PCI/PM: Drain runtime-idle callbacks before driver removal

A race condition between the .runtime_idle() callback and the .remove()
callback in the rtsx_pcr PCI driver leads to a kernel crash due to an
unhandled page fault [1].

The problem is that rtsx_pci_runtime_idle() is not expected to be running
after pm_runtime_get_sync() has been called, but the latter doesn't really
guarantee that. It only guarantees that the suspend and resume callbacks
will not be running when it returns.

However, if a .runtime_idle() callback is already running when
pm_runtime_get_sync() is called, the latter will notice that the runtime PM
status of the device is RPM_ACTIVE and it will return right away without
waiting for the former to complete. In fact, it cannot wait for
.runtime_idle() to complete because it may be called from that callback (it
arguably does not make much sense to do that, but it is not strictly
prohibited).

Thus in general, whoever is providing a .runtime_idle() callback needs
to protect it from running in parallel with whatever code runs after
pm_runtime_get_sync(). [Note that .runtime_idle() will not start after
pm_runtime_get_sync() has returned, but it may continue running then if it
has started earlier.]

One way to address that race condition is to call pm_runtime_barrier()
after pm_runtime_get_sync() (not before it, because a nonzero value of the
runtime PM usage counter is necessary to prevent runtime PM callbacks from
being invoked) to wait for the .runtime_idle() callback to complete should
it be running at that point. A suitable place for doing that is in
pci_device_remove() which calls pm_runtime_get_sync() before removing the
driver, so it may as well call pm_runtime_barrier() subsequently, which
will prevent the race in question from occurring, not just in the rtsx_pcr
driver, but in any PCI drivers providing .runtime_idle() callbacks.

Link: https://lore.kernel.org/lkml/20240229062201.49500-1-kai.heng.feng@canonical.com/ # [1]
Link: https://lore.kernel.org/r/5761426.DvuYhMxLoT@kreacher
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Ricky Wu <ricky_wu@realtek.com>
Acked-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: <stable@vger.kernel.org>

PCI/PM: Allow runtime PM with no PM callbacks at all

Commit c5eb1190074c ("PCI / PM: Allow runtime PM without callback
functions") eliminated the need for PM callbacks in
pci_pm_runtime_suspend() and pci_pm_runtime_resume(), but
didn't do the same for pci_pm_runtime_idle().

Therefore, runtime suspend worked as long as the driver implemented at
least one PM callback. But if the driver doesn't implement any PM
callbacks at all (driver->pm is NULL), pci_pm_runtime_idle() returned
-ENOSYS, which prevented runtime suspend.

Modify pci_pm_runtime_idle() to allow PCI device power state transitions
without runtime PM callbacks and complete the original intention of commit
c5eb1190074c ("PCI / PM: Allow runtime PM without callback functions").

Link: https://lore.kernel.org/r/20240227062648.16579-1-raag.jadav@intel.com
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>

PCI: Make pcie_port_bus_type const

Now that the driver core can properly handle constant struct bus_type, move
the pcie_port_bus_type variable to be a constant structure as well, placing
it into read-only memory which can not be modified at runtime.

Link: https://lore.kernel.org/r/20240208-bus_cleanup-pci2-v1-1-5e578210b6f2@marliere.net
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Place interrupt related code into irq.c

Interrupt related code is spread into irq.c, pci.c, and setup-irq.c.
Group them into pre-existing irq.c.

Link: https://lore.kernel.org/r/20240129113655.3368-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Mark devices disconnected if upstream PCIe link is down on resume

Mark Blakeney reported that when suspending system with a Thunderbolt
dock connected and then unplugging the dock before resume (which is
pretty normal flow with laptops), resuming takes long time.

What happens is that the PCIe link from the root port to the PCIe switch
inside the Thunderbolt device does not train (as expected, the link is
unplugged):

pcieport 0000:00:07.2: restoring config space at offset 0x24 (was 0x3bf12001, writing 0x3bf12001)
pcieport 0000:00:07.0: waiting 100 ms for downstream link
pcieport 0000:01:00.0: not ready 1023ms after resume; giving up

However, at this point we still try to resume the devices below that
unplugged link:

pcieport 0000:01:00.0: Unable to change power state from D3cold to D0, device inaccessible
...
pcieport 0000:01:00.0: restoring config space at offset 0x38 (was 0xffffffff, writing 0x0)
...
pcieport 0000:02:02.0: waiting 100 ms for downstream link, after activation

And this is the link from PCIe switch downstream port to the xHCI on the
dock:

xhci_hcd 0000:03:00.0: not ready 65535ms after resume; giving up
xhci_hcd 0000:03:00.0: Unable to change power state from D3cold to D0, device inaccessible
xhci_hcd 0000:03:00.0: restoring config space at offset 0x3c (was 0xffffffff, writing 0x1ff)

This ends up slowing down the resume time considerably. For this reason
mark these devices as disconnected if the link above them did not train
properly.

Fixes: e8b908146d44 ("PCI/PM: Increase wait time after resume")
Link: https://lore.kernel.org/r/20230918053041.1018876-1-mika.westerberg@linux.intel.com
Reported-by: Mark Blakeney <mark.blakeney@bullet-systems.net>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217915
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v6.4+

PCI: Simplify pci_dev_driver()

Simplify pci_dev_driver() by removing the "else". The "if" case always
returns, so the "else" is superfluous. No functional change intended.

Link: https://lore.kernel.org/r/20230824193712.542167-9-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

PCI: Remove unnecessary initializations

We always assign "fields" immediately, so remove the unnecessary
initializations. No functional change intended.

Link: https://lore.kernel.org/r/20230824193712.542167-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

PCI: Unexport pcie_port_bus_type

pcie_port_bus_type is used only in pci-driver.c and pcie/portdrv_core.c and
pcie/portdrv_pci.c. None of these can be built as modules, so
pcie_port_bus_type doesn't need to be exported. Unexport it.

Link: https://lore.kernel.org/r/20230824193712.542167-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

PCI/PM: Drop pci_bridge_wait_for_secondary_bus() timeout parameter

All callers of pci_bridge_wait_for_secondary_bus() supply a timeout of
PCIE_RESET_READY_POLL_MS, so drop the parameter. Move the definition of
PCIE_RESET_READY_POLL_MS into pci.c, the only user.

[bhelgaas: extracted from
https://lore.kernel.org/r/20230404052714.51315-3-mika.westerberg@linux.intel.com]
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Increase wait time after resume

PCIe r6.0 sec 6.6.1 prescribes that a device must be able to respond to
config requests within 1.0 s (PCI_RESET_WAIT) after exiting conventional
reset and this same delay is prescribed when coming out of D3cold (as that
involves reset too).

A device that requires more than 1 second to initialize after reset may
respond to config requests with Request Retry Status completions (sec
2.3.1), and we accommodate that in Linux with a 60 second cap
(PCIE_RESET_READY_POLL_MS).

Previously we waited up to PCIE_RESET_READY_POLL_MS only in the reset code
path, not in the resume path. However, a device has surfaced, namely Intel
Titan Ridge xHCI, which requires a longer delay also in the resume code
path.

Make the resume code path to use this same extended delay as the reset
path.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216728
Link: https://lore.kernel.org/r/20230404052714.51315-2-mika.westerberg@linux.intel.com
Reported-by: Chris Chiu <chris.chiu@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>

PCI: Unify delay handling for reset and resume

Sheng Bi reports that pci_bridge_secondary_bus_reset() may fail to wait
for devices on the secondary bus to become accessible after reset:

Although it does call pci_dev_wait(), it erroneously passes the bridge's
pci_dev rather than that of a child. The bridge of course is always
accessible while its secondary bus is reset, so pci_dev_wait() returns
immediately.

Sheng Bi proposes introducing a new pci_bridge_secondary_bus_wait()
function which is called from pci_bridge_secondary_bus_reset():

https://lore.kernel.org/linux-pci/20220523171517.32407-1-windy.bi.enflame@gmail.com/

However we already have pci_bridge_wait_for_secondary_bus() which does
almost exactly what we need. So far it's only called on resume from
D3cold (which implies a Fundamental Reset per PCIe r6.0 sec 5.8).
Re-using it for Secondary Bus Resets is a leaner and more rational
approach than introducing a new function.

That only requires a few minor tweaks:

- Amend pci_bridge_wait_for_secondary_bus() to await accessibility of
the first device on the secondary bus by calling pci_dev_wait() after
performing the prescribed delays. pci_dev_wait() needs two parameters,
a reset reason and a timeout, which callers must now pass to
pci_bridge_wait_for_secondary_bus(). The timeout is 1 sec for resume
(PCIe r6.0 sec 6.6.1) and 60 sec for reset (commit 821cdad5c46c ("PCI:
Wait up to 60 seconds for device to become ready after FLR")).
Introduce a PCI_RESET_WAIT macro for the 1 sec timeout.

- Amend pci_bridge_wait_for_secondary_bus() to return 0 on success or
-ENOTTY on error for consumption by pci_bridge_secondary_bus_reset().

- Drop an unnecessary 1 sec delay from pci_reset_secondary_bus() which
is now performed by pci_bridge_wait_for_secondary_bus(). A static
delay this long is only necessary for Conventional PCI, so modern
PCIe systems benefit from shorter reset times as a side effect.

Fixes: 6b2f1351af56 ("PCI: Wait for device to become ready after secondary bus reset")
Link: https://lore.kernel.org/r/da77c92796b99ec568bd070cbe4725074a117038.1673769517.git.lukas@wunner.de
Reported-by: Sheng Bi <windy.bi.enflame@gmail.com>
Tested-by: Ravi Kishore Koppuravuri <ravi.kishore.koppuravuri@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: stable@vger.kernel.org # v4.17+

driver core: make struct bus_type.uevent() take a const *

The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI/PM: Remove unused 'state' parameter to pci_legacy_suspend_late()

1a1daf097e21 ("PCI/PM: Remove unused pci_driver.suspend_late() hook")
removed the legacy .suspend_late() hook, which was the only user of the
"state" parameter to pci_legacy_suspend_late(), but it neglected to remove
the parameter.

Remove the unused "state" parameter to pci_legacy_suspend_late().

Link: https://lore.kernel.org/r/20221025193502.669091-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Simplify pci_pm_suspend_noirq()

We always want to save the device state unless the driver has already done
it. Rearrange the checking in pci_pm_suspend_noirq() to make this more
clear. No functional change intended.

[bhelgaas: commit log, rewrap comment]
Link: https://lore.kernel.org/r/20220830104913.1620539-1-rajvi.jingar@linux.intel.com
Signed-off-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Always disable PTM for all devices during suspend

We want to disable PTM on Root Ports because that allows some chips, e.g.,
Intel mobile chips since Coffee Lake, to enter a lower-power PM state.

That means we also have to disable PTM on downstream devices. PCIe r6.0,
sec 2.2.8, recommends that functions support generation of messages in
non-D0 states, so we have to assume Switch Upstream Ports or Endpoints may
send PTM Requests while in D1, D2, and D3hot. A PTM message received by a
Downstream Port (including a Root Port) with PTM disabled must be treated
as an Unsupported Request (sec 6.21.3).

PTM was previously disabled only for Root Ports, and it was disabled in
pci_prepare_to_sleep(), which is not called at all if a driver supports
legacy PM or does its own state saving.

Instead, disable PTM early in pci_pm_suspend() and pci_pm_runtime_suspend()
so we do it in all cases.

Previously PTM was disabled *after* saving device state, so the state
restore on resume automatically re-enabled it. Since we now disable PTM
*before* saving state, we must explicitly re-enable it in pci_pm_resume()
and pci_pm_runtime_resume().

Here's a sample of errors that occur when PTM is disabled only on the Root
Port. With this topology:

0000:00:1d.0 Root Port to [bus 08-71]
0000:08:00.0 Switch Upstream Port to [bus 09-71]

Kai-Heng reported errors like this:

pcieport 0000:00:1d.0: [20] UnsupReq (First)
pcieport 0000:00:1d.0: AER: TLP Header: 34000000 08000052 00000000 00000000

Decoding TLP header 0x34...... (0011 0100b) and 0x08000052:

Fmt 001b 4 DW header, no data
Type 1 0100b Msg (Local - Terminate at Receiver)
Requester ID 0x0800 Bus 08 Devfn 00.0
Message Code 0x52 0101 0010b PTM Request

The 00:1d.0 Root Port logged an Unsupported Request error when it received
a PTM Request with Requester ID 08:00.0.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215453
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=216210
Fixes: a697f072f5da ("PCI: Disable PTM during suspend to save power")
Link: https://lore.kernel.org/r/20220909202505.314195-10-helgaas@kernel.org
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Rajvi Jingar <rajvi.jingar@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

bus: platform,amba,fsl-mc,PCI: Add device DMA ownership management

The devices on platform/amba/fsl-mc/PCI buses could be bound to drivers
with the device DMA managed by kernel drivers or user-space applications.
Unfortunately, multiple devices may be placed in the same IOMMU group
because they cannot be isolated from each other. The DMA on these devices
must either be entirely under kernel control or userspace control, never
a mixture. Otherwise the driver integrity is not guaranteed because they
could access each other through the peer-to-peer accesses which by-pass
the IOMMU protection.

This checks and sets the default DMA mode during driver binding, and
cleanups during driver unbinding. In the default mode, the device DMA is
managed by the device driver which handles DMA operations through the
kernel DMA APIs (see Documentation/core-api/dma-api.rst).

For cases where the devices are assigned for userspace control through the
userspace driver framework(i.e. VFIO), the drivers(for example, vfio_pci/
vfio_platfrom etc.) may set a new flag (driver_managed_dma) to skip this
default setting in the assumption that the drivers know what they are
doing with the device DMA.

Calling iommu_device_use_default_domain() before {of,acpi}_dma_configure
is currently a problem. As things stand, the IOMMU driver ignored the
initial iommu_probe_device() call when the device was added, since at
that point it had no fwspec yet. In this situation,
{of,acpi}_iommu_configure() are retriggering iommu_probe_device() after
the IOMMU driver has seen the firmware data via .of_xlate to learn that
it actually responsible for the given device. As the result, before
that gets fixed, iommu_use_default_domain() goes at the end, and calls
arch_teardown_dma_ops() if it fails.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20220418005000.897664-5-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

PCI/PM: Replace pci_set_power_state() in pci_pm_thaw_noirq()

Calling pci_set_power_state() to put the given device into D0 in
pci_pm_thaw_noirq() may cause it to restore the device's BARs, which is
redundant before calling pci_restore_state(), so replace it with a direct
pci_power_up() call followed by pci_update_current_state() if it returns a
nonzero value, in analogy with pci_pm_default_resume_early().

Avoid code duplication by introducing a wrapper function to contain the
repeating pattern and calling it in both places.

Link: https://lore.kernel.org/r/3639079.MHq7AAxBmi@kreacher
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Drop the runtime_d3cold device flag

The runtime_d3cold flag is not needed any more, so drop it.

Link: https://lore.kernel.org/r/8077784.T7Z3S40VBb@kreacher
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI/PM: Resume subordinate bus in bus type callbacks

Calling pci_resume_bus() on the secondary bus from pci_power_up() as it is
done now is questionable, because it depends on the mandatory bridge
power-up delays that are only covered by the PCI bus type PM callbacks.

For this reason, move the subordinate bus resume to those callbacks too and
use the observation that if a bridge is being powered-up during resume from
system-wide suspend, it may be still desirable to runtime-resume its
subordinate bus after completing the system-wide transition (in case the
resume of the devices on that bus is skipped during it).

Link: https://lore.kernel.org/r/3190097.aeNJFYEL58@kreacher
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI/PM: Power up all devices during runtime resume

Currently, endpoint devices may not be powered up entirely during runtime
resume that follows a D3hot -> D0 transition of the parent bridge.

Namely, even if the power state of an endpoint device, as indicated by its
PCI_PM_CTRL register, is D0 after powering up its parent bridge, it may be
still necessary to bring its ACPI companion into D0 and that should be done
before accessing it. However, the current code assumes that reading the
PCI_PM_CTRL register is sufficient to establish the endpoint device's power
state, which may lead to problems.

Address that by forcing a power-up of all PCI devices, including the
platform firmware part of it, during runtime resume.

Link: https://lore.kernel.org/linux-pm/11967527.O9o76ZdvQC@kreacher
Fixes: 5775b843a619 ("PCI: Restore config space on runtime resume despite being unbound")
Link: https://lore.kernel.org/r/2652115.mvXUDI8C0e@kreacher
Reported-by: Abhishek Sahu <abhsahu@nvidia.com>
Tested-by: Abhishek Sahu <abhsahu@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI/PM: Define pci_restore_standard_config() only for CONFIG_PM_SLEEP

pci_restore_standard_config() was defined under CONFIG_PM but called only
by pci_pm_resume() (defined under CONFIG_SUSPEND) and pci_pm_restore()
(defined under CONFIG_HIBERNATE_CALLBACKS). A configuration with only
CONFIG_PM leads to a warning:

drivers/pci/pci-driver.c:533:12: error: ‘pci_restore_standard_config’ defined but not used [-Werror=unused-function]

CONFIG_PM_SLEEP depends on CONFIG_SUSPEND and CONFIG_HIBERNATE_CALLBACKS,
so define pci_restore_standard_config() under that instead.

Link: https://lore.kernel.org/r/20220420141135.444820-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

sched/isolation: Use single feature type while referring to housekeeping cpumask

Refer to housekeeping APIs using single feature types instead of flags.
This prevents from passing multiple isolation features at once to
housekeeping interfaces, which soon won't be possible anymore as each
isolation features will have their own cpumask.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org

pci: Decouple HK_FLAG_WQ and HK_FLAG_DOMAIN cpumask fetch

To prepare for supporting each feature of the housekeeping cpumask
toward cpuset, prepare each of the HK_FLAG_* entries to move to their
own cpumask with enforcing to fetch them individually. The new
constraint is that multiple HK_FLAG_* entries can't be mixed together
anymore in a single call to housekeeping cpumask().

This will later allow, for example, to runtime modify the cpulist passed
through "isolcpus=", "nohz_full=" and "rcu_nocbs=" kernel boot
parameters.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-2-frederic@kernel.org

PM: sleep: Add device name to suspend_report_result()

Currently, suspend_report_result() prints only function information.

If any driver uses a common PM function, nobody knows who exactly
called the failing function.

A device pinter is needed to recognize the failing device.

For example:

PM: dpm_run_callback(): pnp_bus_suspend+0x0/0x10 returns 0
PM: dpm_run_callback(): pci_pm_suspend+0x0/0x150 returns 0

become after the change:

serial 00:05: PM: dpm_run_callback(): pnp_bus_suspend+0x0/0x10 returns 0
pci 0000:00:01.3: PM: dpm_run_callback(): pci_pm_suspend+0x0/0x150 returns 0

Signed-off-by: Youngjin Jang <yj84.jang@samsung.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Revert "PCI: Use to_pci_driver() instead of pci_dev->driver"

This reverts commit 2a4d9408c9e8b6f6fc150c66f3fef755c9e20d4a.

Robert reported a NULL pointer dereference caused by the PCI core
(local_pci_probe()) calling the i2c_designware_pci driver's
.runtime_resume() method before the .probe() method. i2c_dw_pci_resume()
depends on initialization done by i2c_dw_pci_probe().

Prior to 2a4d9408c9e8 ("PCI: Use to_pci_driver() instead of
pci_dev->driver"), pci_pm_runtime_resume() avoided calling the
.runtime_resume() method because pci_dev->driver had not been set yet.

2a4d9408c9e8 and b5f9c644eb1b ("PCI: Remove struct pci_dev->driver"),
removed pci_dev->driver, replacing it by device->driver, which *has* been
set by this time, so pci_pm_runtime_resume() called the .runtime_resume()
method when it previously had not.

Fixes: 2a4d9408c9e8 ("PCI: Use to_pci_driver() instead of pci_dev->driver")
Link: https://lore.kernel.org/linux-i2c/CAP145pgdrdiMAT7=-iB1DMgA7t_bMqTcJL4N0=6u8kNY3EU0dw@mail.gmail.com/
Reported-by: Robert Święcki <robert@swiecki.net>
Tested-by: Robert Święcki <robert@swiecki.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Revert "PCI: Remove struct pci_dev->driver"

This reverts commit b5f9c644eb1baafcd349ad134e2110773f8d0a38.

Revert b5f9c644eb1b ("PCI: Remove struct pci_dev->driver"), which is needed
to revert 2a4d9408c9e8 ("PCI: Use to_pci_driver() instead of
pci_dev->driver").

2a4d9408c9e8 caused a NULL pointer dereference reported by Robert Święcki.
Details in the revert of that commit.

Fixes: 2a4d9408c9e8 ("PCI: Use to_pci_driver() instead of pci_dev->driver")
Link: https://lore.kernel.org/linux-i2c/CAP145pgdrdiMAT7=-iB1DMgA7t_bMqTcJL4N0=6u8kNY3EU0dw@mail.gmail.com/
Reported-by: Robert Święcki <robert@swiecki.net>
Tested-by: Robert Święcki <robert@swiecki.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Remove struct pci_dev->driver

There are no remaining uses of the struct pci_dev->driver pointer, so
remove it.

Link: https://lore.kernel.org/r/20211004125935.2300113-12-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Use to_pci_driver() instead of pci_dev->driver

Struct pci_driver contains a struct device_driver, so for PCI devices, it's
easy to convert a device_driver * to a pci_driver * with to_pci_driver().
The device_driver * is in struct device, so we don't need to also keep
track of the pci_driver * in struct pci_dev.

Replace pci_dev->driver with to_pci_driver(). This is a step toward
removing pci_dev->driver.

[bhelgaas: split to separate patch]
Link: https://lore.kernel.org/r/20211004125935.2300113-11-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/ERR: Reduce compile time for CONFIG_PCIEAER=n

The sole non-static function in err.c, pcie_do_recovery(), is only
called from:

* aer.c (if CONFIG_PCIEAER=y)
* dpc.c (if CONFIG_PCIE_DPC=y, which depends on CONFIG_PCIEAER)
* edr.c (if CONFIG_PCIE_EDR=y, which depends on CONFIG_PCIE_DPC)

Thus, err.c need not be compiled if CONFIG_PCIEAER=n.

Also, pci_uevent_ers() and pcie_clear_device_status(), which are called
from err.c, can be #ifdef'ed away unless CONFIG_PCIEAER=y.

Since x86_64_defconfig doesn't enable CONFIG_PCIEAER, this change may
slightly reduce compile time for anyone doing a test build with that
config.

Link: https://lore.kernel.org/r/98f9041151268c1c035ab64cca320ad86803f64a.1627638184.git.lukas@wunner.de
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Drop pci_device_probe() test of !pci_dev->driver

When the device core calls the .probe() callback for a device, the device
is never bound, so pci_dev->driver is always NULL.

Remove the unnecessary test of !pci_dev->driver.

Link: https://lore.kernel.org/r/20211004125935.2300113-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

PCI: Drop pci_device_remove() test of pci_dev->driver

When the driver core calls pci_device_remove(), there is a driver bound
to the device, so pci_dev->driver is never NULL.

Remove the unnecessary test of pci_dev->driver.

Link: https://lore.kernel.org/r/20211004125935.2300113-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

PCI: Correct misspelled and remove duplicated words

Correct a number of misspelled words and remove any words that were
duplicated in the PCI tree. No change to functionality intended.

Link: https://lore.kernel.org/r/20211006233827.147328-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Add 'override_only' field to struct pci_device_id

Add 'override_only' field to struct pci_device_id to be used as part of
pci_match_device().

When set, a driver only matches the entry when dev->driver_override is
set to that driver.

In addition, add a helper macro named 'PCI_DEVICE_DRIVER_OVERRIDE' to
enable setting some data on it.

Next patch from this series will use the above functionality.

Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-10-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Add support for dev_groups to struct pci_driver

This helps converting PCI drivers sysfs attributes to static.

Analogous to' commit b71b283e3d6d ("USB: add support for dev_groups to
struct usb_driver")'

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210512142648.666476-8-andrey.grodzovsky@amd.com

PCI: Fix kernel-doc markup

Update kernel-doc so the names in the doc match the prototypes.

Link: https://lore.kernel.org/r/f19caf7a68f8365c8b573a42b4ac89ec21925c73.1603469755.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Avoid duplicate IDs in driver dynamic IDs list

When a device ID is written to /sys/bus/pci/drivers/.../new_id, we
previously only checked the driver's static ID table for duplicates.
Writing the same ID several times added it to the dynamic IDs list several
times.

This doesn't cause user-visible broken behavior, but remove_id_store() only
removes one of the duplicate IDs, so if we add an ID several times, we
would have to remove it the same number of times before it's completely
gone.

Fix it by calling pci_match_device(), which checks both dynamic and static
IDs to avoid inserting duplicate IDs in dynamic IDs list.

After fix, attempts to add an ID more than once cause an error:

# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/new_id
# echo "1af4 1041" > /sys/bus/pci/drivers/vfio-pci/new_id
bash: echo: write error: File exists

Link: https://lore.kernel.org/r/20201117054409.3428-3-zhenzhong.duan@gmail.com
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Move pci_match_device() ahead of new_id_store()

Move pci_match_device() and its dependencies (pci_match_id() and
pci_device_id_any) ahead of new_id_store().

This is preparation work for calling pci_match_device() in new_id_store().
No functional changes.

[bhelgaas: update function comments]
Link: https://lore.kernel.org/r/20201117054409.3428-2-zhenzhong.duan@gmail.com
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

dma-mapping: move dma-debug.h to kernel/dma/

Most of dma-debug.h is not required by anything outside of kernel/dma.
Move the four declarations needed by dma-mappin.h or dma-ops providers
into dma-mapping.h and dma-map-ops.h, and move the remainder of the
file to kernel/dma/debug.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>

PCI/PM: Remove unused pcibios_pm_ops

The "struct dev_pm_ops pcibios_pm_ops", declared in include/linux/pci.h and
defined in drivers/pci/pci-driver.c, provided arch-specific hooks when a
PCI device was doing a hibernate transition.

394216275c7d ("s390: remove broken hibernate / power management support")
removed the last use of pcibios_pm_ops, so remove it completely.

[bhelgaas: drop unused "error"]
Link: https://lore.kernel.org/r/20200730194416.1029509-1-vaibhavgupta40@gmail.com
Reported-by: Bjorn Helgaas <helgaas@kernel.org>
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Restrict probe functions to housekeeping CPUs

pci_call_probe() prevents the nesting of work_on_cpu() for a scenario
where a VF device is probed from work_on_cpu() of the PF.

Replace the cpumask used in pci_call_probe() from all online CPUs to only
housekeeping CPUs. This is to ensure that there are no additional latency
overheads caused due to the pinning of jobs on isolated CPUs.

Signed-off-by: Alex Belits <abelits@marvell.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lkml.kernel.org/r/20200625223443.2684-3-nitesh@redhat.com

PM: sleep: core: Rename dev_pm_smart_suspend_and_suspended()

Because all callers of dev_pm_smart_suspend_and_suspended use it only
for checking whether or not to skip driver suspend callbacks for a
device, rename it to dev_pm_skip_suspend() in analogy with
dev_pm_skip_resume().

No functional impact.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PM: sleep: core: Rename dev_pm_may_skip_resume()

The name of dev_pm_may_skip_resume() may be easily confused with the
power.may_skip_resume flag which is not checked by that function, so
rename the former as dev_pm_skip_resume().

No functional impact.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PM: sleep: core: Rework the power.may_skip_resume handling

Because the power.may_skip_resume device status bit is taken
into account in combination with the DPM_FLAG_LEAVE_SUSPENDED
driver flag, it can be set to 'true' for all devices in the
"suspend" phase of a suspend-resume cycle, so do that.

Then, neither the PM core nor the middle-layer (sybsystem) code
handling it needs to set it to 'true' any more and it just has
to be cleared if there is a reason to avoid skipping the "noirq"
and "early" resume callbacks provided by the driver, so update
the code in question accordingly.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PM: sleep: core: Do not skip callbacks in the resume phase

The current code in device_resume_noirq() causes the entire early
resume and resume phases of device suspend to be skipped for
devices for which the noirq resume phase have been skipped (due
to the LEAVE_SUSPENDED flag being set) on the premise that those
devices should stay in runtime-suspend after system-wide resume.

However, that may not be correct in two situations. First, the
middle layer (subsystem) noirq resume callback may be missing for
a given device, but its early resume callback may be present and it
may need to do something even if it decides to skip the driver
callback. Second, if the device's wakeup settings were adjusted
in the suspend phase without resuming the device (that was in
runtime suspend at that time), they most likely need to be
adjusted again in the resume phase and so the driver callback
in that phase needs to be run.

For the above reason, modify the core to allow the middle layer
->resume_late callback to run even if its ->resume_noirq callback
is missing (and the core has skipped the driver-level callback
in that phase) and to allow all device callbacks to run in the
resume phase. Also make the core set the PM-runtime status of
devices with SMART_SUSPEND set whose resume callbacks are not
skipped to "active" in the "noirq" resume phase and update the
affected subsystems (PCI and ACPI) accordingly.

After this change, middle-layer (subsystem) callbacks will always
be invoked in all phases of system suspend and resume and driver
callbacks will always run in the prepare, suspend, resume, and
complete phases for all devices.

For devices with SMART_SUSPEND set, driver callbacks will be
skipped in the late and noirq phases of system suspend if those
devices remain in runtime suspend in __device_suspend_late().
Driver callbacks will also be skipped for them during the
noirq and early phases of the "thaw" transition related to
hibernation in that case.

Setting LEAVE_SUSPENDED means that the driver allows its callbacks
to be skipped in the noirq and early phases of system resume, but
some additional conditions need to be met for that to happen (among
other things, the power.may_skip_resume flag needs to be set for the
device during system suspend for the driver callbacks to be skipped
during the subsequent resume transition).

For all devices with SMART_SUSPEND set whose driver callbacks are
invoked during system resume, the PM-runtime status will be set to
"active" (by the core).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Add missing link delays required by the PCIe spec

Currently Linux does not follow PCIe spec regarding the required delays
after reset. A concrete example is a Thunderbolt add-in-card that consists
of a PCIe switch and two PCIe endpoints:

+-1b.0-[01-6b]----00.0-[02-6b]--+-00.0-[03]----00.0 TBT controller
+-01.0-[04-36]-- DS hotplug port
+-02.0-[37]----00.0 xHCI controller
\-04.0-[38-6b]-- DS hotplug port

The root port (1b.0) and the PCIe switch downstream ports are all PCIe Gen3
so they support 8GT/s link speeds.

We wait for the PCIe hierarchy to enter D3cold (runtime):

pcieport 0000:00:1b.0: power state changed by ACPI to D3cold

When it wakes up from D3cold, according to the PCIe 5.0 section 5.8 the
PCIe switch is put to reset and its power is re-applied. This means that we
must follow the rules in PCIe 5.0 section 6.6.1.

For the PCIe Gen3 ports we are dealing with here, the following applies:

With a Downstream Port that supports Link speeds greater than 5.0 GT/s,
software must wait a minimum of 100 ms after Link training completes
before sending a Configuration Request to the device immediately below
that Port. Software can determine when Link training completes by polling
the Data Link Layer Link Active bit or by setting up an associated
interrupt (see Section 6.7.3.3).

Translating this into the above topology we would need to do this (DLLLA
stands for Data Link Layer Link Active):

0000:00:1b.0: wait for 100 ms after DLLLA is set before access to 0000:01:00.0
0000:02:00.0: wait for 100 ms after DLLLA is set before access to 0000:03:00.0
0000:02:02.0: wait for 100 ms after DLLLA is set before access to 0000:37:00.0

I've instrumented the kernel with some additional logging so we can see the
actual delays performed:

pcieport 0000:00:1b.0: power state changed by ACPI to D0
pcieport 0000:00:1b.0: waiting for D3cold delay of 100 ms
pcieport 0000:00:1b.0: waiting for D3hot delay of 10 ms
pcieport 0000:02:01.0: waiting for D3hot delay of 10 ms
pcieport 0000:02:04.0: waiting for D3hot delay of 10 ms

For the switch upstream port (01:00.0 reachable through 00:1b.0 root port)
we wait for 100 ms but not taking into account the DLLLA requirement. We
then wait 10 ms for D3hot -> D0 transition of the root port and the two
downstream hotplug ports. This means that we deviate from what the spec
requires.

Performing the same check for system sleep (s2idle) transitions it turns
out to be even worse. None of the mandatory delays are performed. If this
would be S3 instead of s2idle then according to PCI FW spec 3.2 section
4.6.8. there is a specific _DSM that allows the OS to skip the delays but
this platform does not provide the _DSM and does not go to S3 anyway so no
firmware is involved that could already handle these delays.

On this particular platform these delays are not actually needed because
there is an additional delay as part of the ACPI power resource that is
used to turn on power to the hierarchy but since that additional delay is
not required by any of standards (PCIe, ACPI) it is not present in the
Intel Ice Lake, for example where missing the mandatory delays causes
pciehp to start tearing down the stack too early (links are not yet
trained). Below is an example how it looks like when this happens:

pcieport 0000:83:04.0: pciehp: Slot(4): Card not present
pcieport 0000:87:04.0: PME# disabled
pcieport 0000:83:04.0: pciehp: pciehp_unconfigure_device: domain:bus:dev = 0000:86:00
pcieport 0000:86:00.0: Refused to change power state, currently in D3
pcieport 0000:86:00.0: restoring config space at offset 0x3c (was 0xffffffff, writing 0x201ff)
pcieport 0000:86:00.0: restoring config space at offset 0x38 (was 0xffffffff, writing 0x0)
...

There is also one reported case (see the bugzilla link below) where the
missing delay causes xHCI on a Titan Ridge controller fail to runtime
resume when USB-C dock is plugged. This does not involve pciehp but instead
the PCI core fails to runtime resume the xHCI device:

pcieport 0000:04:02.0: restoring config space at offset 0xc (was 0x10000, writing 0x10020)
pcieport 0000:04:02.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100406)
xhci_hcd 0000:39:00.0: Refused to change power state, currently in D3
xhci_hcd 0000:39:00.0: restoring config space at offset 0x3c (was 0xffffffff, writing 0x1ff)
xhci_hcd 0000:39:00.0: restoring config space at offset 0x38 (was 0xffffffff, writing 0x0)
...

Add a new function pci_bridge_wait_for_secondary_bus() that is called on
PCI core resume and runtime resume paths accordingly if the bridge entered
D3cold (and thus went through reset).

This is second attempt to add the missing delays. The previous solution in
c2bf1fc212f7 ("PCI: Add missing link delays required by the PCIe spec") was
reverted because of two issues it caused:

1. One system become unresponsive after S3 resume due to PME service
spinning in pcie_pme_work_fn(). The root port in question reports that
the xHCI sent PME but the xHCI device itself does not have PME status
set. The PME status bit is never cleared in the root port resulting
the indefinite loop in pcie_pme_work_fn().

2. Slows down resume if the root/downstream port does not support Data
Link Layer Active Reporting because pcie_wait_for_link_delay() waits
1100 ms in that case.

This version should avoid the above issues because we restrict the delay to
happen only if the port went into D3cold.

Link: https://lore.kernel.org/linux-pci/SL2P216MB01878BBCD75F21D882AEEA2880C60@SL2P216MB0187.KORP216.PROD.OUTLOOK.COM/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203885
Link: https://lore.kernel.org/r/20191112091617.70282-3-mika.westerberg@linux.intel.com
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Move power state update away from pci_power_up()

Move the invocation of pci_update_current_state() from pci_power_up() to
pci_pm_default_resume_early(), which is the only caller of that function.

Preparatory change, no functional impact.

Link: https://lore.kernel.org/r/37482337.udjOGdOKNb@kreacher
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI/PM: Remove unused pci_driver.suspend_late() hook

The struct pci_driver.suspend_late() hook is one of the legacy PCI power
management callbacks, and there are no remaining users of it. Remove it.

Link: https://lore.kernel.org/r/20191101204558.210235-7-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Remove unused pci_driver.resume_early() hook

The struct pci_driver.resume_early() hook is one of the legacy PCI power
management callbacks, and there are no remaining users of it. Remove it.

Link: https://lore.kernel.org/r/20191101204558.210235-6-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Use pci_WARN() to include device information

Add and use pci_WARN() wrappers so warnings include device information.

Link: https://lore.kernel.org/r/20191017212851.54237-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Use PCI dev_printk() wrappers for consistency

Use the PCI dev_printk() wrappers for consistency with the rest of the PCI
core. No functional change intended.

Link: https://lore.kernel.org/r/20191017212851.54237-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Make power management op coding style consistent

Some of the power management ops use this style:

struct device_driver *drv = dev->driver;
if (drv && drv->pm && drv->pm->prepare(dev))
drv->pm->prepare(dev);

while others use this:

const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
if (pm && pm->runtime_resume)
pm->runtime_resume(dev);

Convert the first style to the second so they're all consistent. Remove
local "error" variables when unnecessary. No functional change intended.

Link: https://lore.kernel.org/r/20191014230016.240912-6-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Run resume fixups before disabling wakeup events

pci_pm_resume() and pci_pm_restore() call pci_pm_default_resume(), which
runs resume fixups before disabling wakeup events:

static void pci_pm_default_resume(struct pci_dev *pci_dev)
{
pci_fixup_device(pci_fixup_resume, pci_dev);
pci_enable_wake(pci_dev, PCI_D0, false);
}

pci_pm_runtime_resume() does both of these, but in the opposite order:

pci_enable_wake(pci_dev, PCI_D0, false);
pci_fixup_device(pci_fixup_resume, pci_dev);

We should always use the same ordering unless there's a reason to do
otherwise. Change pci_pm_runtime_resume() to call pci_pm_default_resume()
instead of open-coding this, so the fixups are always done before disabling
wakeup events.

pci_pm_default_resume() is called from pci_pm_runtime_resume(), which is
under #ifdef CONFIG_PM. If SUSPEND and HIBERNATION are disabled, PM_SLEEP
is disabled also, so move pci_pm_default_resume() from #ifdef
CONFIG_PM_SLEEP to #ifdef CONFIG_PM.

Link: https://lore.kernel.org/r/20191014230016.240912-5-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Clear PCIe PME Status even for legacy power management

Previously, pci_pm_resume_noirq() cleared the PME Status bit in the Root
Status register only if the device had no driver or the driver did not
implement legacy power management. It should clear PME Status regardless
of what sort of power management the driver supports, so do this before
checking for legacy power management.

This affects Root Ports and Root Complex Event Collectors, for which the
usual driver is the PCIe portdrv, which implements new power management, so
this change is just on principle, not to fix any actual defects.

Fixes: a39bd851dccf ("PCI/PM: Clear PCIe PME Status bit in core, not PCIe port driver")
Link: https://lore.kernel.org/r/20191014230016.240912-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Always return devices to D0 when thawing

pci_pm_thaw_noirq() is supposed to return the device to D0 and restore its
configuration registers, but previously it only did that for devices whose
drivers implemented the new power management ops.

Hibernation, e.g., via "echo disk > /sys/power/state", involves freezing
devices, creating a hibernation image, thawing devices, writing the image,
and powering off. The fact that thawing did not return devices with legacy
power management to D0 caused errors, e.g., in this path:

pci_pm_thaw_noirq
if (pci_has_legacy_pm_support(pci_dev)) # true for Mellanox VF driver
return pci_legacy_resume_early(dev) # ... legacy PM skips the rest
pci_set_power_state(pci_dev, PCI_D0)
pci_restore_state(pci_dev)
pci_pm_thaw
if (pci_has_legacy_pm_support(pci_dev))
pci_legacy_resume
drv->resume
mlx4_resume
...
pci_enable_msix_range
...
if (dev->current_state != PCI_D0) # <---
return -EINVAL;

which caused these warnings:

mlx4_core a6d1:00:02.0: INTx is not supported in multi-function mode, aborting
PM: dpm_run_callback(): pci_pm_thaw+0x0/0xd7 returns -95
PM: Device a6d1:00:02.0 failed to thaw: error -95

Return devices to D0 and restore config registers for all devices, not just
those whose drivers support new power management.

[bhelgaas: also call pci_restore_state() before pci_legacy_resume_early(),
update comment, add stable tag, commit log]
Link: https://lore.kernel.org/r/KU1P153MB016637CAEAD346F0AA8E3801BFAD0@KU1P153MB0166.APCP153.PROD.OUTLOOK.COM
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org # v4.13+

PCI: PM: Simplify bus-level hibernation callbacks

After a previous change causing all runtime-suspended PCI devices
to be resumed before creating a snapshot image of memory during
hibernation, it is not necessary to worry about the case in which
them might be left in runtime-suspend any more, so get rid of the
code related to that from bus-level PCI hibernation callbacks.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

PM: ACPI/PCI: Resume all devices during hibernation

Both the PCI bus type and the ACPI PM domain avoid resuming
runtime-suspended devices with DPM_FLAG_SMART_SUSPEND set during
hibernation (before creating the snapshot image of system memory),
but that turns out to be a mistake. It leads to functional issues
and adds complexity that's hard to justify.

For this reason, resume all runtime-suspended PCI devices and all
devices in the ACPI PM domains before creating a snapshot image of
system memory during hibernation.

Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
Link: https://lore.kernel.org/linux-acpi/917d4399-2e22-67b1-9d54-808561f9083f@uwyo.edu/T/#maf065fe6e4974f2a9d79f332ab99dfaba635f64c
Reported-by: Robert R. Howell <RHowell@uwyo.edu>
Tested-by: Robert R. Howell <RHowell@uwyo.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

PCI: PM/ACPI: Refresh all stale power state data in pci_pm_complete()

In pci_pm_complete() there are checks to decide whether or not to
resume devices that were left in runtime-suspend during the preceding
system-wide transition into a sleep state. They involve checking the
current power state of the device and comparing it with the power
state of it set before the preceding system-wide transition, but the
platform component of the device's power state is not handled
correctly in there.

Namely, on platforms with ACPI, the device power state information
needs to be updated with care, so that the reference counters of
power resources used by the device (if any) are set to ensure that
the refreshed power state of it will be maintained going forward.

To that end, introduce a new ->refresh_state() platform PM callback
for PCI devices, for asking the platform to refresh the device power
state data and ensure that the corresponding power state will be
maintained going forward, make it invoke acpi_device_update_power()
(for devices with ACPI PM) on platforms with ACPI and make
pci_pm_complete() use it, through a new pci_refresh_power_state()
wrapper function.

Fixes: a0d2a959d3da (PCI: Avoid unnecessary resume after direct-complete)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI: PM: Avoid skipping bus-level PM on platforms without ACPI

There are platforms that do not call pm_set_suspend_via_firmware(),
so pm_suspend_via_firmware() returns 'false' on them, but the power
states of PCI devices (PCIe ports in particular) are changed as a
result of powering down core platform components during system-wide
suspend. Thus the pm_suspend_via_firmware() checks in
pci_pm_suspend_noirq() and pci_pm_resume_noirq() introduced by
commit 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to-
idle") are not sufficient to determine that devices left in D0
during suspend will remain in D0 during resume and so the bus-level
power management can be skipped for them.

For this reason, introduce a new global suspend flag,
PM_SUSPEND_FLAG_NO_PLATFORM, set it for suspend-to-idle only
and replace the pm_suspend_via_firmware() checks mentioned above
with checks against this flag.

Fixes: 3e26c5feed2a ("PCI: PM: Skip devices in D0 for suspend-to-idle")
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI: PM: Replace pci_dev_keep_suspended() with two functions

The code in pci_dev_keep_suspended() is relatively hard to follow due
to the negative checks in it and in its callers and the function has
a possible side-effect (disabling the PME) which doesn't really match
its role.

For this reason, move the PME disabling from pci_dev_keep_suspended()
to a separate function and change the semantics (and name) of the
rest of it, so that 'true' is returned when the device needs to be
resumed (and not the other way around). Change the callers of
pci_dev_keep_suspended() accordingly.

While at it, make the code flow in pci_pm_poweroff() reflect the
pci_pm_suspend() more closely to avoid arbitrary differences between
them.

This is a cosmetic change with no intention to alter behavior.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI: PM: Skip devices in D0 for suspend-to-idle

Commit d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue")
attempted to avoid a problem with devices whose drivers want them to
stay in D0 over suspend-to-idle and resume, but it did not go as far
as it should with that.

Namely, first of all, the power state of a PCI bridge with a
downstream device in D0 must be D0 (based on the PCI PM spec r1.2,
sec 6, table 6-1, if the bridge is not in D0, there can be no PCI
transactions on its secondary bus), but that is not actively enforced
during system-wide PM transitions, so use the skip_bus_pm flag
introduced by commit d491f2b75237 for that.

Second, the configuration of devices left in D0 (whatever the reason)
during suspend-to-idle need not be changed and attempting to put them
into D0 again by force is pointless, so explicitly avoid doing that.

Fixes: d491f2b75237 ("PCI: PM: Avoid possible suspend-to-idle issue")
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

PCI: Always allow probing with driver_override

Commit 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control
VF driver binding") introduced the sriov_drivers_autoprobe attribute
which allows users to prevent the kernel from automatically probing a
driver for new VFs as they are created. This allows VFs to be spawned
without automatically binding the new device to a host driver, such as
in cases where the user intends to use the device only with a meta
driver like vfio-pci. However, the current implementation prevents any
use of drivers_probe with the VF while sriov_drivers_autoprobe=0. This
blocks the now current general practice of setting driver_override
followed by using drivers_probe to bind a device to a specified driver.

The kernel never automatically sets a driver_override therefore it seems
we can assume a driver_override reflects the intent of the user. Also,
probing a device using a driver_override match seems outside the scope
of the 'auto' part of sriov_drivers_autoprobe. Therefore, let's allow
driver_override matches regardless of sriov_drivers_autoprobe, which we
can do by simply testing if a driver_override is set for a device as a
'can probe' condition.

Fixes: 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding")
Link: https://lore.kernel.org/lkml/155742996741.21878.569845487290798703.stgit@gimli.home
Link: https://lore.kernel.org/linux-pci/155672991496.20698.4279330795743262888.stgit@gimli.home/T/#u
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Return error if cannot probe VF

Commit 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control
VF driver binding") allows the user to specify that drivers for VFs of
a PF should not be probed, but it actually causes pci_device_probe() to
return success back to the driver core in this case. Therefore by all
sysfs appearances the device is bound to a driver, the driver link from
the device exists as does the device link back from the driver, yet the
driver's probe function is never called on the device. We also fail to
do any sort of cleanup when we're prohibited from probing the device,
the IRQ setup remains in place and we even hold a device reference.

Instead, abort with errno before any setup or references are taken when
pci_device_can_probe() prevents us from trying to probe the device.

Link: https://lore.kernel.org/lkml/155672991496.20698.4279330795743262888.stgit@gimli.home
Fixes: 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: PM: Avoid possible suspend-to-idle issue

If a PCI driver leaves the device handled by it in D0 and calls
pci_save_state() on the device in its ->suspend() or ->suspend_late()
callback, it can expect the device to stay in D0 over the whole
s2idle cycle. However, that may not be the case if there is a
spurious wakeup while the system is suspended, because in that case
pci_pm_suspend_noirq() will run again after pci_pm_resume_noirq()
which calls pci_restore_state(), via pci_pm_default_resume_early(),
so state_saved is cleared and the second iteration of
pci_pm_suspend_noirq() will invoke pci_prepare_to_sleep() which
may change the power state of the device.

To avoid that, add a new internal flag, skip_bus_pm, that will be set
by pci_pm_suspend_noirq() when it runs for the first time during the
given system suspend-resume cycle if the state of the device has
been saved already and the device is still in D0. Setting that flag
will cause the next iterations of pci_pm_suspend_noirq() to set
state_saved for pci_pm_resume_noirq(), so that it always restores the
device state from the originally saved data, and avoid calling
pci_prepare_to_sleep() for the device.

Fixes: 33e4f80ee69b ("ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively

%pF and %pf are functionally equivalent to %pS and %ps conversion
specifiers. The former are deprecated, therefore switch the current users
to use the preferred variant.

The changes have been produced by the following command:

git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \
while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done

And verifying the result.

Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: xen-devel@lists.xenproject.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: drbd-dev@lists.linbit.com
Cc: linux-block@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Cc: linux-pci@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-btrfs@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-mm@kvack.org
Cc: ceph-devel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: David Sterba <dsterba@suse.com> (for btrfs)
Acked-by: Mike Rapoport <rppt@linux.ibm.com> (for mm/memblock.c)
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (for drivers/pci)
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

PCI: Clean up usage of __u32 type

The double underscore types are meant for compatibility in userspace
headers which does not apply here. Therefore, change to use the standard
no-underscore types.

The origin of the double underscore types dates back to before the git era
so I was not able to find a commit to see the original justification.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Remove unused attr variable in pci_dma_configure

Clang warns:

drivers/pci/pci-driver.c:1603:21: error: unused variable 'attr'
[-Werror,-Wunused-variable]

Commit e5361ca29f2f ("ACPI / scan: Refactor _CCA enforcement") removed
attr's use and replaced it with its assigned value so it is no longer
needed.

Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ACPI / scan: Refactor _CCA enforcement

Rather than checking the DMA attribute at each callsite, just pass it
through for acpi_dma_configure() to handle directly. That can then deal
with the relatively exceptional DEV_DMA_NOT_SUPPORTED case by explicitly
installing dummy DMA ops instead of just skipping setup entirely. This
will then free up the dev->dma_ops == NULL case for some valuable
fastpath optimisations.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Tony Luck <tony.luck@intel.com>

PCI / PM: Allow runtime PM without callback functions

a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM")
nullified the runtime PM suspend/resume callback pointers while keeping the
runtime PM enabled.

This caused the SMBus PCI device to stay in D0 with
/sys/devices/.../power/runtime_status showing "error" when the runtime PM
framework attempted to autosuspend the device. This is due to PCI bus
runtime PM, which checks for driver runtime PM callbacks and returns
-ENOSYS if they are not set.

Since i2c-i801.c doesn't need to do anything device-specific for runtime
PM, Jean Delvare proposed this be fixed in the PCI core rather than adding
dummy runtime PM callback functions in the PCI drivers.

Change pci_pm_runtime_suspend()/pci_pm_runtime_resume() so they allow
changing the PCI device power state during runtime PM transitions even if
the driver supplies no runtime PM callbacks.

This fixes the runtime PM regression on i2c-i801.c.

It is not obvious why the code previously required the runtime PM
callbacks. The test has been there since the code was introduced by
6cbf82148ff2 ("PCI PM: Run-time callbacks for PCI bus type").

On the other hand, a similar change was done to generic runtime PM
callbacks in 05aa55dddb9e ("PM / Runtime: Lenient generic runtime pm
callbacks").

Fixes: a9c8088c7988 ("i2c: i801: Don't restore config registers on runtime PM")
Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org # v4.18+

PCI: Call dma_debug_add_bus() for pci_bus_type from PCI core

There is nothing arch-specific about PCI or dma-debug, so call
dma_debug_add_bus() from the PCI core just after registering the bus type.

Most of dma-debug is already generic; this just adds reporting of pending
dma-allocations on driver unload for arches other than powerpc, sh, and
x86.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

PCI/IOV: Reset total_VFs limit after detaching PF driver

The TotalVFs register in the SR-IOV capability is the hardware limit on the
number of VFs. A PF driver can limit the number of VFs further with
pci_sriov_set_totalvfs(). When the PF driver is removed, reset any VF
limit that was imposed by the driver because that limit may not apply to
other drivers.

Before 8d85a7a4f2c9 ("PCI/IOV: Allow PF drivers to limit total_VFs to 0"),
pci_sriov_set_totalvfs(pdev, 0) meant "we can enable TotalVFs virtual
functions", and the nfp driver used that to remove the VF limit when the
driver unloads.

8d85a7a4f2c9 broke that because instead of removing the VF limit,
pci_sriov_set_totalvfs(pdev, 0) actually sets the limit to zero, and that
limit persists even if another driver is loaded.

We could fix that by making the nfp driver reset the limit when it unloads,
but it seems more robust to do it in the PCI core instead of relying on the
driver.

The regression scenario is:

nfp_pci_probe (driver 1)
...
nfp_pci_remove
pci_sriov_set_totalvfs(pf->pdev, 0) # limits VFs to 0

...
nfp_pci_probe (driver 2)
nfp_rtsym_read_le("nfd_vf_cfg_max_vfs")
# no VF limit from firmware

Now driver 2 is broken because the VF limit is still 0 from driver 1.

Fixes: 8d85a7a4f2c9 ("PCI/IOV: Allow PF drivers to limit total_VFs to 0")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
[bhelgaas: changelog, rename functions]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI / PM: Do not clear state_saved for devices that remain suspended

The state_saved flag should not be cleared in pci_pm_suspend() if the
given device is going to remain suspended, or the device's config
space will not be restored properly during the subsequent resume.

Namely, if the device is going to stay in suspend, both the late
and noirq callbacks return early for it, so if its state_saved flag
is cleared in pci_pm_suspend(), it will remain unset throughout the
remaining part of suspend and resume and pci_restore_state() called
for the device going forward will return without doing anything.

For this reason, change pci_pm_suspend() to only clear state_saved
if the given device is not going to remain suspended. [This is
analogous to what commit ae860a19f37c (PCI / PM: Do not clear
state_saved in pci_pm_freeze() when smart suspend is set) did for
hibernation.]

Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
Cc: 4.15+ <stable@vger.kernel.org> # 4.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/AER: Factor out error reporting to drivers/pci/pcie/err.c

Move the error reporting callbacks from aerdrv_core.c to err.c, where they
can be used by DPC in addition to AER.

As part of aerdrv_core.c, these callbacks were built under CONFIG_PCIEAER.
Moving them to the new err.c means they will now be built under
CONFIG_PCIEPORTBUS, so adjust the definition of pci_uevent_ers() to match.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
[bhelgaas: in reset_link(), initialize "driver" even if CONFIG_PCIEAER is
unset, update pci_uevent_ers() #ifdef wrapper]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers: remove force dma flag from buses

With each bus implementing its own DMA configuration callback, there is no
need for bus to explicitly set the force_dma flag. Modify the
of_dma_configure function to accept an input parameter which specifies if
implicit DMA configuration is required when it is not described by the
firmware.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # PCI parts
Reviewed-by: Rob Herring <robh@kernel.org>
[hch: tweaked the changelog a bit]
Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: move dma configuration to bus infrastructure

ACPI/OF support for configuration of DMA is a bus specific aspect, and
thus should be configured by the bus. Introduces a 'dma_configure' bus
method so that busses can control their DMA capabilities.

Also update the PCI, Platform, ACPI and host1x buses to use the new
method.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # PCI parts
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[hch: simplified host1x_dma_configure based on a comment from Thierry,
rewrote changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>

PCI / PM: Do not clear state_saved in pci_pm_freeze() when smart suspend is set

If a driver uses DPM_FLAG_SMART_SUSPEND and the device is already
runtime suspended when hibernate is started PCI core skips runtime
resuming the device but still clears pci_dev->state_saved. After the
hibernation image is written pci_pm_thaw_noirq() makes sure subsequent
thaw phases for the device are also skipped leaving it runtime suspended
with pci_dev->state_saved == false.

When the device is eventually runtime resumed pci_pm_runtime_resume()
restores config space by calling pci_restore_standard_config(), however
because pci_dev->state_saved == false pci_restore_state() never actually
restores the config space leaving the device in a state that is not what
the driver might expect.

For example here is what happens for intel-lpss I2C devices once the
hibernation snapshot is taken:

intel-lpss 0000:00:15.0: power state changed by ACPI to D0
intel-lpss 0000:00:1e.0: power state changed by ACPI to D3cold
video LNXVIDEO:00: Restoring backlight state
PM: hibernation exit
i2c_designware i2c_designware.1: Unknown Synopsys component type: 0xffffffff
i2c_designware i2c_designware.0: Unknown Synopsys component type: 0xffffffff
i2c_designware i2c_designware.1: timeout in disabling adapter
i2c_designware i2c_designware.0: timeout in disabling adapter

Since PCI config space is not restored the device is still in D3hot
making MMIO register reads return 0xffffffff.

Fix this by clearing pci_dev->state_saved only if we actually end up
runtime resuming the device.

Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: 4.15+ <stable@vger.kernel.org> # 4.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/portdrv: Remove pcie_port_bus_type link order dependency

The pcie_port_bus_type must be registered before drivers that depend on it
can be registered. Those drivers include:

pcied_init() # PCIe native hotplug driver
aer_service_init() # AER driver
dpc_service_init() # DPC driver
pcie_pme_service_init() # PME driver

Previously we registered pcie_port_bus_type from pcie_portdrv_init(), a
device_initcall. The callers of pcie_port_service_register() (above) are
also device_initcalls. This is fragile because the device_initcall
ordering depends on link order, which is not explicit.

Register pcie_port_bus_type from pci_driver_init() along with pci_bus_type.
This removes the link order dependency between portdrv and the pciehp, AER,
DPC, and PCIe PME drivers.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

PCI/PM: Clear PCIe PME Status bit for Root Complex Event Collectors

Per PCIe r4.0, sec 6.1.6, Root Complex Event Collectors can generate PME
interrupts on behalf of Root Complex Integrated Endpoints.

Linux does not currently enable PME interrupts from RC Event Collectors,
but fe31e69740ed ("PCI/PCIe: Clear Root PME Status bits early during system
resume") suggests PME interrupts may be enabled by the platform for ACPI-
based runtime wakeup.

Clear the PCIe PME Status bit for Root Complex Event Collectors during
resume, just like we already do for Root Ports.

If the BIOS enables PME interrupts for an event collector and neglects to
clear the status bit on resume, this change should fix the same bug as
fe31e69740ed (PMEs not working after waking from a sleep state), but for
Root Complex Integrated Endpoints.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI: Tidy comments

Remove pointless comments that tell us the file name, remove blank line
comments, follow multi-line comment conventions. No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Restore config space on runtime resume despite being unbound

We leave PCI devices not bound to a driver in D0 during runtime suspend.
But they may have a parent which is bound and can be transitioned to
D3cold at runtime. Once the parent goes to D3cold, the unbound child
may go to D3cold as well. When the child goes to D3cold, its internal
state, including configuration of BARs, MSI, ASPM, MPS, etc., is lost.

One example are recent hybrid graphics laptops which cut power to the
discrete GPU when the root port above it goes to ACPI power state D3.
Users may provoke this by unbinding the GPU driver and allowing runtime
PM on the GPU via sysfs: The PM core will then treat the GPU as
"suspended", which in turn allows the root port to runtime suspend,
causing the power resources listed in its _PR3 object to be powered off.
The GPU's BARs will be uninitialized when a driver later probes it.

Another example are hybrid graphics laptops where the GPU itself (rather
than the root port) is capable of runtime suspending to D3cold. If the
GPU's integrated HDA controller is not bound and the GPU's driver
decides to runtime suspend to D3cold, the HDA controller's BARs will be
uninitialized when a driver later probes it.

Fix by saving and restoring config space over a runtime suspend cycle
even if the device is not bound.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Peter Wu <peter@lekensteyn.nl> # Nvidia Optimus
Tested-by: Lukas Wunner <lukas@wunner.de> # MacBook Pro
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
[lukas: add commit message, bikeshed code comments for clarity]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://patchwork.freedesktop.org/patch/msgid/92fb6e6ae2730915eb733c08e2f76c6a313e3860.1520068884.git.lukas@wunner.de

PCI/PM: Clear PCIe PME Status bit in core, not PCIe port driver

fe31e69740ed ("PCI/PCIe: Clear Root PME Status bits early during system
resume") added a .resume_noirq() callback to the PCIe port driver to clear
the PME Status bit during resume to work around a BIOS issue.

The BIOS evidently enabled PME interrupts for ACPI-based runtime wakeups
but did not clear the PME Status bit during resume, which meant PMEs after
resume did not trigger interrupts because PME Status did not transition
from cleared to set.

The fix was in the PCIe port driver, so it worked when CONFIG_PCIEPORTBUS
was set. But I think we *always* want the fix because the platform may use
PME interrupts even if Linux is built without the PCIe port driver.

Move the fix from the port driver to the PCI core so we can work around
this "PME doesn't work after waking from a sleep state" issue regardless of
CONFIG_PCIEPORTBUS.

[bhelgaas: folded in warning fix from Arnd Bergmann <arnd@arndb.de>:
https://lkml.kernel.org/r/20180328134747.2062348-1-arnd@arndb.de]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/AER: Move pci_uevent_ers() out of pci.h

There's no reason pci_uevent_ers() needs to be inline in pci.h, so move it
out to a C file.

Given it's used by AER the obvious location would be somewhere in
drivers/pci/pcie/aer, but because it's also used by powerpc EEH code
unfortunately that doesn't work in the case where EEH is enabled but
PCIEPORTBUS is not.

So for now put it in pci-driver.c, next to pci_uevent(), with an
appropriate #ifdef so it's not built if AER and EEH are both disabled.

While we're moving it also fix up the kernel doc comment for @pdev to be
accurate.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Reviewed-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>

PCI: Add SPDX GPL-2.0 to replace GPL v2 boilerplate

Add SPDX GPL-2.0 to all PCI files that specified the GPL version 2 license.

Remove the boilerplate GPL version 2 language, relying on the assertion in
b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") that the SPDX identifier may be used instead of the
full boilerplate text.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI / PM: Remove spurious semicolon

The trailing semicolon is an empty statement that does no operation.
Removing it since it doesn't do anything.

Signed-off-by: Luis de Bethencourt <luisbg@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI / PM: Force devices to D0 in pci_pm_thaw_noirq()

It is incorrect to call pci_restore_state() for devices in low-power
states (D1-D3), as that involves the restoration of MSI setup which
requires MMIO to be operational and that is only the case in D0.

However, pci_pm_thaw_noirq() may do that if the driver's "freeze"
callbacks put the device into a low-power state, so fix it by making
it force devices into D0 via pci_set_power_state() instead of trying
to "update" their power state which is pointless.

Fixes: e60514bd4485 (PCI/PM: Restore the status of PCI devices across hibernation)
Cc: 4.13+ <stable@vger.kernel.org> # 4.13+
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Maarten Lankhorst <dev@mblankhorst.nl>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Maarten Lankhorst <dev@mblankhorst.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PM / sleep: Avoid excess pm_runtime_enable() calls in device_resume()

Middle-layer code doing suspend-time optimizations for devices with
the DPM_FLAG_SMART_SUSPEND flag set (currently, the PCI bus type and
the ACPI PM domain) needs to make the core skip ->thaw_early and
->thaw callbacks for those devices in some cases and it sets the
power.direct_complete flag for them for this purpose.

However, it turns out that setting power.direct_complete outside of
the PM core is a bad idea as it triggers an excess invocation of
pm_runtime_enable() in device_resume().

For this reason, provide a helper to clear power.is_late_suspended
and power.is_suspended to be invoked by the middle-layer code in
question instead of setting power.direct_complete and make that code
call the new helper.

Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI / PM: Support for LEAVE_SUSPENDED driver flag

Add support for DPM_FLAG_LEAVE_SUSPENDED to the PCI bus type by
making it (a) set the power.may_skip_resume status bit for devices
that, from its perspective, may be left in suspend after system
wakeup from sleep and (b) return early from pci_pm_resume_noirq()
for devices whose remaining resume callbacks during the transition
under way are going to be skipped by the PM core.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI / PM: Take SMART_SUSPEND driver flag into account

Make the PCI bus type take DPM_FLAG_SMART_SUSPEND into account in its
system-wide PM callbacks and make sure that all code that should not
run in parallel with pci_pm_runtime_resume() is executed in the "late"
phases of system suspend, freeze and poweroff transitions.

[Note that the pm_runtime_suspended() check in pci_dev_keep_suspended()
is an optimization, because if is not passed, all of the subsequent
checks may be skipped and some of them are much more overhead in
general.]

Also use the observation that if the device is in runtime suspend
at the beginning of the "late" phase of a system-wide suspend-like
transition, its state cannot change going forward (runtime PM is
disabled for it at that time) until the transition is over and the
subsequent system-wide PM callbacks should be skipped for it (as
they generally assume the device to not be suspended), so add checks
for that in pci_pm_suspend_late/noirq(), pci_pm_freeze_late/noirq()
and pci_pm_poweroff_late/noirq().

Moreover, if pci_pm_resume_noirq() or pci_pm_restore_noirq() is
called during the subsequent system-wide resume transition and if
the device was left in runtime suspend previously, its runtime PM
status needs to be changed to "active" as it is going to be put
into the full-power state, so add checks for that too to these
functions.

In turn, if pci_pm_thaw_noirq() runs after the device has been
left in runtime suspend, the subsequent "thaw" callbacks need
to be skipped for it (as they may not work correctly with a
suspended device), so set the power.direct_complete flag for the
device then to make the PM core skip those callbacks.

In addition to the above add a core helper for checking if
DPM_FLAG_SMART_SUSPEND is set and the device runtime PM status is
"suspended" at the same time, which is done quite often in the new
code (and will be done elsewhere going forward too).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI / PM: Drop unnecessary invocations of pcibios_pm_ops callbacks

The only user of non-empty pcibios_pm_ops is s390 and it only uses
"noirq" callbacks, so drop the invocations of the other pcibios_pm_ops
callbacks from the PCI PM code.

That will allow subsequent changes to be somewhat simpler.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags

The motivation for this change is to provide a way to work around
a problem with the direct-complete mechanism used for avoiding
system suspend/resume handling for devices in runtime suspend.

The problem is that some middle layer code (the PCI bus type and
the ACPI PM domain in particular) returns positive values from its
system suspend ->prepare callbacks regardless of whether the driver's
->prepare returns a positive value or 0, which effectively prevents
drivers from being able to control the direct-complete feature.
Some drivers need that control, however, and the PCI bus type has
grown its own flag to deal with this issue, but since it is not
limited to PCI, it is better to address it by adding driver flags at
the core level.

To that end, add a driver_flags field to struct dev_pm_info for flags
that can be set by device drivers at the probe time to inform the PM
core and/or bus types, PM domains and so on on the capabilities and/or
preferences of device drivers. Also add two static inline helpers
for setting that field and testing it against a given set of flags
and make the driver core clear it automatically on driver remove
and probe failures.

Define and document two PM driver flags related to the direct-
complete feature: NEVER_SKIP and SMART_PREPARE that can be used,
respectively, to indicate to the PM core that the direct-complete
mechanism should never be used for the device and to inform the
middle layer code (bus types, PM domains etc) that it can only
request the PM core to use the direct-complete mechanism for
the device (by returning a positive value from its ->prepare
callback) if it also has been requested by the driver.

While at it, make the core check pm_runtime_suspended() when
setting power.direct_complete so that it doesn't need to be
checked by ->prepare callbacks.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers: flag buses which demand DMA configuration

We do not want the common dma_configure() pathway to apply
indiscriminately to all devices, since there are plenty of buses which
do not have DMA capability, and if their child devices were used for
DMA API calls it would only be indicative of a driver bug. However,
there are a number of buses for which DMA is implicitly expected even
when not described by firmware - those we whitelist with an automatic
opt-in to dma_configure(), assuming that the DMA address space and the
physical address space are equivalent if not otherwise specified.

Commit 723288836628 ("of: restrict DMA configuration") introduced a
short-term fix by comparing explicit bus types, but this approach is far
from pretty, doesn't scale well, and fails to cope at all with bus
drivers which may be built as modules, like host1x. Let's refine things
by making that opt-in a property of the bus type, which neatly addresses
those problems and lets the decision of whether firmware description of
DMA capability should be optional or mandatory stay internal to the bus
drivers themselves.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

PCI / PM: Add dev_dbg() to print device suspend power states

It sometimes is useful to know what power states the kernel thinks
it puts PCI devices into during system suspend, so add a dev_dbg()
statement for that.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI / PM: Do not resume any devices in pci_pm_prepare()

It should not be necessary to resume devices with ignore_children set
in pci_pm_prepare(), because they should be resumed explicitly by
their children drivers during suspend if need be and they will be
resumed by pci_pm_suspend() after that anyway, so avoid doing that.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/IB: add support for pci driver attribute groups

Some drivers (specifically the nes IB driver), want to create a lot of
sysfs driver attributes. Instead of open-coding the creation and
removal of these files (and getting it wrong btw), it's a better idea to
let the driver core handle all of this logic for us.

So add a new field to the pci driver structure, **groups, that allows
pci drivers to specify an attribute group list it wishes to have created
when it is registered with the driver core.

Big bonus is now the driver doesn't race with userspace when the sysfs
files are created vs. when the kobject is announced, so any script/tool
that actually wanted to use these files will not have to poll waiting
for them to show up.

Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

PCI / PM: Skip bridges in pci_enable_wake()

PCI bridges only have a reason to generate wakeup signals on behalf
of devices below them, so avoid preparing bridges for wakeup directly
in pci_enable_wake().

Also drop the pci_has_subordinate() check from pci_pm_default_resume()
as this will be done by pci_enable_wake() itself now.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI / PM: Restore PME Enable after config space restoration

Commit dc15e71eefc7 (PCI / PM: Restore PME Enable if skipping wakeup
setup) introduced a mechanism by which the PME Enable bit can be
restored by pci_enable_wake() if dev->wakeup_prepared is set in
case it has been overwritten by PCI config space restoration.

However, that commit overlooked the fact that on some systems (Dell
XPS13 9360 in particular) the AML handling wakeup events checks PME
Status and PME Enable and it won't trigger a Notify() for devices
where those bits are not set while it is running.

That happens during resume from suspend-to-idle when pci_restore_state()
invoked by pci_pm_default_resume_early() clears PME Enable before the
wakeup events are processed by AML, effectively causing those wakeup
events to be ignored.

Fix this issue by restoring the PME Enable configuration right after
pci_restore_state() has been called instead of doing that in
pci_enable_wake().

Fixes: dc15e71eefc7 (PCI / PM: Restore PME Enable if skipping wakeup setup)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Add a call to pci_assign_irq() in pci_device_probe()

The pci_assign_irq() function allows assignment of an IRQ to devices during
device enable time rather than only at boot. Therefore call it in the
pci_device_probe() function during the enable device code path so this
assignment can be performed.

This patch will do nothing on arches which do not set the IRQ mapping
function pointers and is therefore currently a nop, however as support for
these function pointers is added to arch-specific code this will cause IRQ
assignment to migrate to device enable time allowing the new code paths to
be used.

Signed-off-by: Matthew Minter <matt@masarand.com>
[lorenzo.pieralisi@arm.com: moved pci_assign_irq() call site]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Restore the status of PCI devices across hibernation

Currently we saw a lot of "No irq handler" errors during hibernation, which
caused the system hang finally:

ata4.00: qc timeout (cmd 0xec)
ata4.00: failed to IDENTIFY (I/O error, err_mask=0x4)
ata4.00: revalidation failed (errno=-5)
ata4: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
do_IRQ: 31.151 No irq handler for vector

According to above logs, there is an interrupt triggered and it is
dispatched to CPU31 with a vector number 151, but there is no handler for
it, thus this IRQ will not get acked and will cause an IRQ flood which
kills the system. To be more specific, the 31.151 is an interrupt from the
AHCI host controller.

After some investigation, the reason why this issue is triggered is because
the thaw_noirq() function does not restore the MSI/MSI-X settings across
hibernation.

The scenario is illustrated below:

1. Before hibernation, IRQ 34 is the handler for the AHCI device, which
is bound to CPU31.

2. Hibernation starts, the AHCI device is put into low power state.

3. All the nonboot CPUs are put offline, so IRQ 34 has to be migrated to
the last alive one - CPU0.

4. After the snapshot has been created, all the nonboot CPUs are brought
up again; IRQ 34 remains bound to CPU0.

5. AHCI devices are put into D0.

6. The snapshot is written to the disk.

The issue is triggered in step 6. The AHCI interrupt should be delivered
to CPU0, however it is delivered to the original CPU31 instead, which
causes the "No irq handler" issue.

Ying Huang has provided a clue that, in step 3 it is possible that writing
to the register might not take effect as the PCI devices have been
suspended.

In step 3, the IRQ 34 affinity should be modified from CPU31 to CPU0, but
in fact it is not. In __pci_write_msi_msg(), if the device is already in
low power state, the low level MSI message entry will not be updated but
cached. During the device restore process after a normal suspend/resume,
pci_restore_msi_state() writes the cached MSI back to the hardware.

But this is not the case for hibernation. pci_restore_msi_state() is not
currently called in pci_pm_thaw_noirq(), although pci_save_state() has
saved the necessary PCI cached information in pci_pm_freeze_noirq().

Restore the PCI status for the device during hibernation. Otherwise the
status might be lost across hibernation (for example, settings for MSI,
MSI-X, ATS, ACS, IOV, etc.), which might cause problems during hibernation.

Suggested-by: Ying Huang <ying.huang@intel.com>
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org
Cc: Len Brown <len.brown@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: Ying Huang <ying.huang@intel.com>

PCI / PM: Simplify device wakeup settings code

After previous changes it is not necessary to distinguish between
device wakeup for run time and device wakeup from system sleep states
any more, so rework the PCI device wakeup settings code accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: pci-driver: convert to use DRIVER_ATTR_WO

We are trying to get rid of DRIVER_ATTR(), and all of the pci-driver
core driver attributes can be trivially changed to use DRIVER_ATTR_WO().

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: <linux-pci@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Replace the racy recursion prevention

pci_call_probe() can called recursively when a physcial function is probed
and the probing creates virtual functions, which are populated via
pci_bus_add_device() which in turn can end up calling pci_call_probe()
again.

The code has an interesting way to prevent recursing into the workqueue
code. That's accomplished by a check whether the current task runs already
on the numa node which is associated with the device.

While that works to prevent the recursion into the workqueue code, it's
racy versus normal execution as there is no guarantee that the node does
not vanish after the check.

There is another issue with this code. It dereferences cpumask_of_node()
unconditionally without checking whether the node is available.

Make the detection reliable by:

- Mark a probed device as 'is_probed' in pci_call_probe()

- Check in pci_call_probe for a virtual function. If it's a virtual
function and the associated physical function device is marked
'is_probed' then this is a recursive call, so the call can be invoked in
the calling context.

- Add a check whether the node is online before dereferencing it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-pci@vger.kernel.org
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.771457199@linutronix.de

PCI: Use cpu_hotplug_disable() instead of get_online_cpus()

Converting the hotplug locking, i.e. get_online_cpus(), to a percpu rwsem
unearthed a circular lock dependency which was hidden from lockdep due to
the lockdep annotation of get_online_cpus() which prevents lockdep from
creating full dependency chains. There are several variants of this. And
example is:

Chain exists of:

cpu_hotplug_lock.rw_sem --> drm_global_mutex --> &item->mutex

CPU0 CPU1
---- ----
lock(&item->mutex);
lock(drm_global_mutex);
lock(&item->mutex);
lock(cpu_hotplug_lock.rw_sem);

because there are dependencies through workqueues. The call chain is:

get_online_cpus
apply_workqueue_attrs
__alloc_workqueue_key
ttm_mem_global_init
ast_ttm_mem_global_init
drm_global_item_ref
ast_mm_init
ast_driver_load
drm_dev_register
drm_get_pci_dev
ast_pci_probe
local_pci_probe
work_for_cpu_fn
process_one_work
worker_thread

This is not a problem of get_online_cpus() recursion, it's a possible
deadlock undetected by lockdep so far.

The cure is to use cpu_hotplug_disable() instead of get_online_cpus() to
protect the PCI probing.

There is a side effect to this: cpu_hotplug_disable() makes a concurrent
cpu hotplug attempt via the sysfs interfaces fail with -EBUSY, but PCI
probing usually happens during the boot process where no interaction is
possible. Any later invocations are infrequent enough and concurrent
hotplug attempts are so unlikely that the danger of user space visible
regressions is very close to zero. Anyway, thats preferrable over a real
deadlock.


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-pci@vger.kernel.org
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.691198590@linutronix.de

PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding

Sometimes it is not desirable to bind SR-IOV VFs to drivers. This can save
host side resource usage by VF instances that will be assigned to VMs.

Add a new PCI sysfs interface "sriov_drivers_autoprobe" to control that
from the PF. To modify it, echo 0/n/N (disable probe) or 1/y/Y (enable
probe) to:

/sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/sriov_drivers_autoprobe

Note that this must be done before enabling VFs. The change will not take
effect if VFs are already enabled. Simply, one can disable VFs by setting
sriov_numvfs to 0, choose whether to probe or not, and then re-enable the
VFs by restoring sriov_numvfs.

[bhelgaas: changelog, ABI doc]
Signed-off-by: Bodong Wang <bodong@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>

PCI/MSI: Stop disabling MSI/MSI-X in pci_device_shutdown()

The pci_bus_type .shutdown method, pci_device_shutdown(), is called from
device_shutdown() in the kernel restart and shutdown paths.

Previously, pci_device_shutdown() called pci_msi_shutdown() and
pci_msix_shutdown(). This disables MSI and MSI-X, which causes the device
to fall back to raising interrupts via INTx. But the driver is still bound
to the device, it doesn't know about this change, and it likely doesn't
have an INTx handler, so these INTx interrupts cause "nobody cared"
warnings like this:

irq 16: nobody cared (try booting with the "irqpoll" option)
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.2-1.el7_UNSUPPORTED.x86_64 #1
Hardware name: Hewlett-Packard HP Z820 Workstation/158B, BIOS J63 v03.90 06/
...

The MSI disabling code was added by d52877c7b1af ("pci/irq: let
pci_device_shutdown to call pci_msi_shutdown v2") because a driver left MSI
enabled and kdump failed because the kexeced kernel wasn't prepared to
receive the MSI interrupts.

Subsequent commits 1851617cd2da ("PCI/MSI: Disable MSI at enumeration even
if kernel doesn't support MSI") and e80e7edc55ba ("PCI/MSI: Initialize MSI
capability for all architectures") changed the kexeced kernel to disable
all MSIs itself so it no longer depends on the crashed kernel to clean up
after itself.

Stop disabling MSI/MSI-X in pci_device_shutdown(). This resolves the
"nobody cared" unhandled IRQ issue above. It also allows PCI serial
devices, which may rely on the MSI interrupts, to continue outputting
messages during reboot/shutdown.

[bhelgaas: changelog, drop pci_msi_shutdown() and pci_msix_shutdown() calls
altogether]
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=187351
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Alex Williamson <alex.williamson@redhat.com>
CC: David Arcari <darcari@redhat.com>
CC: Myron Stowe <mstowe@redhat.com>
CC: Lukas Wunner <lukas@wunner.de>
CC: Keith Busch <keith.busch@intel.com>
CC: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI: Remove duplicate check for positive return value from probe() functions

Function __pci_device_probe() tries to be careful about a PCI driver
probe() hook returning a positive value, but this is not really necessary,
since the same fix up is already done in local_pci_probe() (preceded by a
noisy warning), which renders this instance dead code.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: implement num_vf bus type callback

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

PCI: Avoid unnecessary resume after direct-complete

Commit 58a1fbbb2ee8 ("PM / PCI / ACPI: Kick devices that might have been
reset by firmware") added a runtime resume for devices that were runtime
suspended when the system entered sleep.

The motivation was that devices might be in a reset-power-on state after
waking from system sleep, so their power state as perceived by Linux
(stored in pci_dev->current_state) would no longer reflect reality. By
resuming such devices, we allow them to return to a low-power state via
autosuspend and also bring their current_state in sync with reality.

However for devices that are *not* in a reset-power-on state, doing an
unconditional resume wastes energy. A more refined approach is called for
which issues a runtime resume only if the power state after direct-complete
is shallower than it was before. To achieve this, update the device's
current_state and compare it to its pre-sleep value.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI: Drop CONFIG_KEXEC_CORE ifdeffery

Drop the CONFIG_KEXEC_CORE #ifdef around reference to "kexec_in_progress".

Commit 2b94ed245861 ("kexec: define kexec_in_progress in !CONFIG_KEXEC
case") has made this unnecessary.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Put PCIe ports into D3 during suspend

Currently the Linux PCI core does not touch power state of PCI bridges and
PCIe ports when system suspend is entered. Leaving them in D0 consumes
power unnecessarily and may prevent the CPU from entering deeper C-states.

With recent PCIe hardware we can power down the ports to save power given
that we take into account few restrictions:

- The PCIe port hardware is recent enough, starting from 2015.

- Devices connected to PCIe ports are effectively in D3cold once the port
is transitioned to D3 (the config space is not accessible anymore and
the link may be powered down).

- Devices behind the PCIe port need to be allowed to transition to D3cold
and back. There is a way both drivers and userspace can forbid this.

- If the device behind the PCIe port is capable of waking the system it
needs to be able to do so from D3cold.

This patch adds a new flag to struct pci_device called 'bridge_d3'. This
flag is set and cleared by the PCI core whenever there is a change in power
management state of any of the devices behind the PCIe port. When system
later on is suspended we only need to check this flag and if it is true
transition the port to D3 otherwise we leave it in D0.

Also provide override mechanism via command line parameter
"pcie_port_pm=[off|force]" that can be used to disable or enable the
feature regardless of the BIOS manufacturing date.

Tested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI / PM: Tune down retryable runtime suspend error messages

The runtime PM core doesn't treat EBUSY and EAGAIN retvals from the driver
suspend hooks as errors, but they still show up as errors in dmesg. Tune
them down. See rpm_suspend() for details of handling these return values.

Note that we use dev_dbg() for the retryable retvals, so after this
change you'll need either CONFIG_DYNAMIC_DEBUG or CONFIG_PCI_DEBUG
for them to show up in the log.

One problem caused by this was noticed by Daniel: the i915 driver
returns EAGAIN to signal a temporary failure to suspend and as a request
towards the RPM core for scheduling a suspend again. This is a normal
event, but the resulting error message flags a breakage during the
driver's automated testing which parses dmesg and picks up the error.

Reported-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://bugs.freedesktop.org/show_bug.cgi?id=92992
Signed-off-by: Imre Deak <imre.deak@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / PCI / ACPI: Kick devices that might have been reset by firmware

There is a concern that if the platform firmware was involved in
the system resume that's being completed, some devices might have
been reset by it and if those devices had the power.direct_complete
flag set during the preceding suspend transition, they may stay
in a reset-power-on state indefinitely (until they are runtime-resumed
and then suspended again). That may not be a big deal from the
individual device's perspective, but if the system is an SoC, it may
be prevented from entering deep SoC-wide low-power states on idle
because of that.

The devices that are most likely to be affected by this issue are
PCI devices and ACPI-enumerated devices using the general ACPI PM
domain, so to prevent it from happening for those devices, force a
runtime resume for them if they have their power.direct_complete
flags set and the platform firmware was involved in the resume
transition currently in progress.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Drop pm_request_idle() from pm_generic_complete()

The pm_request_idle() in pm_generic_complete() is pointless as it is
called with the runtime PM usage counter different from zero (bumped
up by the core during the prepare phase of system suspend) and the
core calls pm_runtime_put() for all devices after executing their
complete callbacks, so drop it.

This allows the PCI PM layer to use pm_generic_complete() too.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

PCI / PM: Avoid resuming more devices during system suspend

Commit bac2a909a096 (PCI / PM: Avoid resuming PCI devices during
system suspend) introduced a mechanism by which some PCI devices that
were runtime-suspended at the system suspend time might be left in
that state for the duration of the system suspend-resume cycle.
However, it overlooked devices that were marked as capable of waking
up the system just because PME support was detected in their PCI
config space.

Namely, in that case, device_can_wakeup(dev) returns 'true' for the
device and if the device is not configured for system wakeup,
device_may_wakeup(dev) returns 'false' and it will be resumed during
system suspend even though configuring it for system wakeup may not
really make sense at all.

To avoid this problem, simply disable PME for PCI devices that have
not been configured for system wakeup and are runtime-suspended at
the system suspend time for the duration of the suspend-resume cycle.

If the device is in D3cold, its config space is not available and it
shouldn't be written to, but that's only possible if the device
has platform PM support and the platform code is responsible for
checking whether or not the device's configuration is suitable for
system suspend in that case.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI / PM: Update runtime PM documentation for PCI devices

Section 3.2 "Device Runtime Power Management" of pci.txt has become
outdated, so update it to correctly reflect the current code flow.

Also update the comment in local_pci_probe() to document the fact
that pm_runtime_put_noidle() is not the only runtime PM helper
function that can be used to decrement the device's runtime PM
usage counter in .probe().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>

PCI: Remove unnecessary "if" statement

In store_remove_id(), set the default return value to -ENODEV, and
overwrite it with the input buffer size if we find a matching list entry.
Then we don't need to test whether to return an error or the count.

No functional change.

[bhelgaas: changelog]
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

kexec: split kexec_load syscall from kexec core code

There are two kexec load syscalls, kexec_load another and kexec_file_load.
kexec_file_load has been splited as kernel/kexec_file.c. In this patch I
split kexec_load syscall code to kernel/kexec.c.

And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.

The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use
kexec_load syscall can bypass the checking.

Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.

Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig. Also updated general kernel code with to
kexec_load syscall.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PCI: Add pcibios_alloc_irq() and pcibios_free_irq()

Add pcibios_alloc_irq() and pcibios_free_irq(), which are called when
binding/unbinding PCI device drivers.

PCI arch code may implement these to manage IRQ resources for hotplugged
devices.

[bhelgaas: changelog]
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

PCI / PM: Avoid resuming PCI devices during system suspend

Commit f25c0ae2b4c4 (ACPI / PM: Avoid resuming devices in ACPI PM
domain during system suspend) modified the ACPI PM domain's system
suspend callbacks to allow devices attached to it to be left in the
runtime-suspended state during system suspend so as to optimize
the suspend process.

This was based on the general mechanism introduced by commit
aae4518b3124 (PM / sleep: Mechanism to avoid resuming runtime-suspended
devices unnecessarily).

Extend that approach to PCI devices by modifying the PCI bus type's
->prepare callback to return 1 for devices that are runtime-suspended
when it is being executed and that are in a suitable power state and
need not be resumed going forward.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Generate uppercase hex for modalias var in uevent

Some implementations of modprobe fail to load the driver for a PCI device
automatically because the "interface" part of the modalias from the kernel
is lowercase, and the modalias from file2alias is uppercase.

The "interface" is the low-order byte of the Class Code, defined in PCI
r3.0, Appendix D. Most interface types defined in the spec do not use
alpha characters, so they won't be affected. For example, 00h, 01h, 10h,
20h, etc. are unaffected.

Print the "interface" byte of the Class Code in uppercase hex, as we
already do for the Vendor ID, Device ID, Class, etc.

Commit 89ec3dcf17fd ("PCI: Generate uppercase hex for modalias interface
class") fixed only half of the problem. Some udev implementations rely on
the uevent file and not the modalias file.

Fixes: d1ded203adf1 ("PCI: add MODALIAS to hotplug event for pci devices")
Fixes: 89ec3dcf17fd ("PCI: Generate uppercase hex for modalias interface class")
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: stable@vger.kernel.org

PCI / PM: Drop CONFIG_PM_RUNTIME from the PCI core

After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PCI core code.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI: Fix comment typo 'COMFIG_PM_OPS'

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

PCI: Remove unnecessary variable in pci_add_dynid()

The variable "retval" in pci_add_dynid() is only used to store the return
value of driver_attach() and is then directly returned. Remove the
variable and directly pass on driver_attach()'s return value.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Add pci_fixup_suspend_late quirk pass

Add pci_fixup_suspend_late as a new pci_fixup_pass. The pass is called
from suspend_noirq and poweroff_noirq. Using the same pass for suspend
and hibernate is consistent with resume_early which is called by
resume_noirq and restore_noirq.

The new quirk pass is required for Thunderbolt support on Apple
hardware.

Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Whitespace cleanup

Fix various whitespace errors.

No functional change.

[bhelgaas: fix other similar problems]
Signed-off-by: Ryan Desfosses <ryan@desfo.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Move EXPORT_SYMBOL so it immediately follows function/variable

Move EXPORT_SYMBOL so it immediately follows the function or variable.

No functional change.

[bhelgaas: squash similar changes, fix hotplug, probe, rom, search, too]
Signed-off-by: Ryan Desfosses <ryan@desfo.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Introduce new device binding path using pci_dev.driver_override

The driver_override field allows us to specify the driver for a device
rather than relying on the driver to provide a positive match of the
device. This shortcuts the existing process of looking up the vendor and
device ID, adding them to the driver new_id, binding the device, then
removing the ID, but it also provides a couple advantages.

First, the above existing process allows the driver to bind to any device
matching the new_id for the window where it's enabled. This is often not
desired, such as the case of trying to bind a single device to a meta
driver like pci-stub or vfio-pci. Using driver_override we can do this
deterministically using:

echo pci-stub > /sys/bus/pci/devices/0000:03:00.0/driver_override
echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind
echo 0000:03:00.0 > /sys/bus/pci/drivers_probe

Previously we could not invoke drivers_probe after adding a device to
new_id for a driver as we get non-deterministic behavior whether the driver
we intend or the standard driver will claim the device. Now it becomes a
deterministic process, only the driver matching driver_override will probe
the device.

To return the device to the standard driver, we simply clear the
driver_override and reprobe the device:

echo > /sys/bus/pci/devices/0000:03:00.0/driver_override
echo 0000:03:00.0 > /sys/bus/pci/devices/0000:03:00.0/driver/unbind
echo 0000:03:00.0 > /sys/bus/pci/drivers_probe

Another advantage to this approach is that we can specify a driver override
to force a specific binding or prevent any binding. For instance when an
IOMMU group is exposed to userspace through VFIO we require that all
devices within that group are owned by VFIO. However, devices can be
hot-added into an IOMMU group, in which case we want to prevent the device
from binding to any driver (override driver = "none") or perhaps have it
automatically bind to vfio-pci. With driver_override it's a simple matter
for this field to be set internally when the device is first discovered to
prevent driver matches.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Rename pci_is_bridge() to pci_has_subordinate()

Previously, pci_is_bridge() returned true only when a subordinate bus
existed. Rename pci_is_bridge() to pci_has_subordinate() to better
indicate what we're checking.

No functional change.

[bhelgaas: changelog]
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Remove dead code

"pdev" can never be NULL here, so remove the test.

Found by Coverity (CID 744313).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Fail new_id for vendor/device values already built into driver

While using the sysfs new_id interface, the user can unintentionally feed
incorrect values if the driver static table has a matching entry. This is
possible since only the device and vendor fields are mandatory and the rest
are optional. As a result, store_new_id() will fill in default values that
are then passed on to the driver and can have unintended consequences.

As an example, consider the ixgbe driver and the 82599EB network card:

echo "8086 10fb" > /sys/bus/pci/drivers/ixgbe/new_id

This will pass a pci_device_id with driver_data = 0 to ixgbe_probe(), which
uses that zero to index a table of card operations. The zeroth entry of
the table does *not* correspond to the 82599 operations.

This change returns an error if the user attempts to add a dynid for a
vendor/device combination for which a static entry already exists.
However, if the user intentionally wants a different set of values, she
must provide all the 7 fields and that will be accepted.

[bhelgaas: drop KVM text since the problem isn't KVM-specific]
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>

PCI / PM: Resume runtime-suspended devices later during system suspend

Runtime-suspended devices are resumed during system suspend by
pci_pm_prepare() for two reasons: First, because they may need
to be reprogrammed in order to change their wakeup settings and,
second, because they may need to be operatonal for their children
to be successfully suspended. That is a problem, though, if there
are many runtime-suspended devices that need to be resumed this
way during system suspend, because the .prepare() PM callbacks of
devices are executed sequentially and the times taken by them
accumulate, which may increase the total system suspend time quite
a bit.

For this reason, move the resume of runtime-suspended devices up
to the next phase of device suspend (during system suspend), except
for the ones that have power.ignore_children set. The exception is
made, because the devices with power.ignore_children set may still
be necessary for their children to be successfully suspended (during
system suspend) and they won't be resumed automatically as a result
of the runtime resume of their children.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Disable Bus Master only on kexec reboot

Add a flag to tell the PCI subsystem that kernel is shutting down in
preparation to kexec a kernel. Add code in PCI subsystem to use this flag
to clear Bus Master bit on PCI devices only in case of kexec reboot.

This fixes a power-off problem on Acer Aspire V5-573G and likely other
machines and avoids any other issues caused by clearing Bus Master bit on
PCI devices in normal shutdown path. The problem was introduced by
b566a22c2332 ("PCI: disable Bus Master on PCI device shutdown").

This patch is based on discussion at
http://marc.info/?l=linux-pci&m=138425645204355&w=2

Link: https://bugzilla.kernel.org/show_bug.cgi?id=63861
Reported-by: Chang Liu <cl91tp@gmail.com>
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: stable@vger.kernel.org # v3.5+

PCI: Avoid unnecessary CPU switch when calling driver .probe() method

If we are already on a CPU local to the device, call the driver .probe()
method directly without using work_on_cpu().

This is a workaround for a lockdep warning in the following scenario:

pci_call_probe
work_on_cpu(cpu, local_pci_probe, ...)
driver .probe
pci_enable_sriov
...
pci_bus_add_device
...
pci_call_probe
work_on_cpu(cpu, local_pci_probe, ...)

It would be better to fix PCI so we don't call VF driver .probe() methods
from inside a PF driver .probe() method, but that's a bigger project.

[bhelgaas: open bugzilla, rework comments & changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=65071
Link: http://lkml.kernel.org/r/CAE9FiQXYQEAZ=0sG6+2OdffBqfLS9MpoN1xviRR9aDbxPxcKxQ@mail.gmail.com
Link: http://lkml.kernel.org/r/20130624195942.40795.27292.stgit@ahduyck-cp1.jf.intel.com
Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Yinghai Lu <yinghai@kernel.org>

PCI: Fix whitespace, capitalization, and spelling errors

Fix whitespace, capitalization, and spelling errors. No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.

Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI: Warn on driver probe return value greater than zero

Ages ago, drivers could return values greater than zero from their probe
function and this would be regarded as success.

But after f3ec4f87d607 ("PCI: change device runtime PM settings for probe
and remove") and 967577b06241 ("PCI/PM: Keep runtime PM enabled for unbound
PCI devices"), we set dev->driver to NULL if the driver's probe function
returns a value greater than zero.

__pci_device_probe() treats this as success, and drivers can still mostly
work even with dev->driver == NULL, but PCI power management doesn't work,
and we don't call the driver's remove function on rmmod.

To help catch these driver problems, issue a warning in this case.

[bhelgaas: changelog]
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Remove pci_pm_complete()

88d26136 ("PM: Prevent runtime suspend during system resume") removed the
pm_runtime_put_sync() from pci_pm_complete() to PM core code
device_complete().

Here the pci_pm_complete() is doing the same work which can be done in
device_complete(), so we can remove it directly.

Signed-off-by: Liu Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI: Make pci_dev_pm_ops static

pci_dev_pm_ops is local to pci-driver.c. Make it static.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: convert bus code to use dev_groups

The dev_attrs field of struct bus_type is going away soon, dev_groups
should be used instead. This converts the PCI bus code to use the
correct field.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: convert bus code to use drv_groups

The drv_attrs field of struct bus_type is going away soon, drv_groups
should be used instead. This converts the PCI bus code to use the
correct field.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: convert bus code to use bus_groups

The bus_attrs field of struct bus_type is going away soon, dev_groups
should be used instead. This converts the PCI bus code to use the
correct field.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: convert bus code to use drv_groups

The drv_attrs field of struct bus_type is going away soon, drv_groups
should be used instead. This converts the PCI bus code to use the
correct field.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: convert bus code to use bus_groups

The bus_attrs field of struct bus_type is going away soon, dev_groups
should be used instead. This converts the PCI bus code to use the
correct field.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Add pcibios_pm_ops for optional arch-specific hibernate functionality

Platforms may want to provide architecture-specific functionality when
a PCI device is doing a hibernate transition. Add a weak symbol
pcibios_pm_ops that architectures can override to do so.

[bhelgaas: fold in return value checks from v2 patch]
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PM / Runtime: Rework the "runtime idle" helper routine

The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0. If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.

Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.

To reduce overall code bloat, make the changes described above.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>

PCI: Don't try to disable Bus Master on disconnected PCI devices

This is a fix for commit 7897e60227 ("PCI: Disable Bus Master
unconditionally in pci_device_shutdown()"). Vivek reported that
with this commit, kexec failed because none of his SATA disks
came up.

A ->shutdown() callback might put the device in D3cold, which means config
space is no longer available.

[bhelgaas: changelog]
Link: https://lkml.org/lkml/2013/3/12/529
Reported-and-Tested-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Clear state_saved during suspend

This patch clears pci_dev->state_saved at the beginning of suspending.
PCI config state may be saved long before that. Some drivers call
pci_save_state() from the ->probe() callback to get snapshot of sane
configuration space to use in the ->slot_reset() callback.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> # add comment
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Disable Bus Master unconditionally in pci_device_shutdown()

Commit b566a22c23 ("PCI: disable Bus Master on PCI device shutdown")
used pci_disable_device(), but that doesn't disable Bus Mastering
unconditionally; we allow nested enable/disable calls, and only the
last disable call actually does anything.

This uses pci_clear_master() to unconditionally clear the Bus Master
bit.

Matthew Garrett and Alan Cox said (see LKML link below) that clearing Bus
Master for all PCI devices may lead to unpredictable consequences: some
devices ignores this bit and continue DMA, some of them hang after that or
crash the whole system. But we're already trying to clear Bus Master in
general because of b566a22c23; this merely deals with the cases where
drivers haven't shut down the device correctly.

[bhelgaas: changelog]
Link: https://lkml.org/lkml/2012/6/6/278
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI: Skip attaching driver in device_add()

We want to add PCI devices to the device tree as early as possible but
delay attaching drivers.

device_add() adds a device to the device hierarchy and (via
device_attach()) attaches a matching driver and calls its .probe() method.
We want to separate adding the device to the hierarchy from attaching the
driver.

This patch does that by adding "match_driver" in struct pci_dev. When
false, we return failure from pci_bus_match(), which makes device_attach()
believe there's no matching driver.

Later, we set "match_driver = true" and call device_attach() again, which
now attaches the driver and calls its .probe() method.

[bhelgaas: changelog, explicitly init dev->match_driver,
fold device_attach() call into pci_bus_add_device()]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/PM: Keep runtime PM enabled for unbound PCI devices

For unbound PCI devices, what we need is:

- Always in D0 state, because some devices do not work again after
being put into D3 by the PCI bus.

- In SUSPENDED state if allowed, so that the parent devices can still
be put into low power state.

To satisfy these requirements, the runtime PM for the unbound PCI
devices are disabled and set to SUSPENDED state. One issue of this
solution is that the PCI devices will be put into SUSPENDED state even
if the SUSPENDED state is forbidden via the sysfs interface
(.../power/control) of the device. This is not an issue for most
devices, because most PCI devices are not used at all if unbound.
But there are exceptions. For example, unbound VGA card can be used
for display, but suspending its parents makes it stop working.

To fix the issue, we keep the runtime PM enabled when the PCI devices
are unbound. But the runtime PM callbacks will do nothing if the PCI
devices are unbound. This way, we can put the PCI devices into
SUSPENDED state without putting the PCI devices into D3 state.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=48201
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: stable@vger.kernel.org # v3.6+

PCI: Move pci_uevent into pci-driver.c

With the demise of CONFIG_HOTPLUG as an option, the pci_uevent
function located in hotplug.c will now always be used and doesn't need
special treatment in the Makefile. Move pci_uevent into pci-driver.c
and remove hotplug.c

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Remove CONFIG_HOTPLUG ifdefs

Remove conditional code based on CONFIG_HOTPLUG being false. It's
always on now in preparation of it going away as an option.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI: Don't touch card regs after runtime suspend D3

If the driver takes care of state saving, don't touch any registers on it.

Optimus (dual-gpu) laptops seem to have their own form of D3cold, but
unfortunately enter it on normal D3 transitions via the ACPI callback.

So when we use runtime PM to transition to D3, the card disappears off
the PCI bus, however we then try to access registers on it in the
runtime suspend finish, which really doesn't work.

This patch checks whether the pci state is saved and doesn't attempt to hit
any registers after that point if it is.

(Looks okay to Rafael)

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Resume device before shutdown

Some actions during shutdown need device to be in D0 state, such as
MSI shutdown etc, so resume device before shutdown.

Without this patch, a device may not be enumerated after a kexec
because the corresponding bridge is not in D0, so that
configuration space of the device is not accessible.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: stable@vger.kernel.org # v3.6+

PM: Prevent runtime suspend during system resume

This patch (as1591) moves the pm_runtime_get_noresume() and
pm_runtime_put_sync() calls from __device_suspend() and
device_resume() to device_prepare() and device_complete() in the PM
core.

The reason for doing this is to make sure that parent devices remain
at full power (i.e., don't go into runtime suspend) while their
children are being resumed from a system sleep.

The PCI core already contained equivalent code to serve the same
purpose. The patch removes the duplicated code, since it is no longer
needed. One of the comments from the PCI core gets moved into the PM
core, and a second comment is added to explain whe the _get_noresume
and _put_sync calls are present.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PCI: Convert "new_id"/"remove_id" into generic pci_bus driver attributes

This patch removes hardcoded sysfs attributes manipulation and
converts them into generic pci_bus->drv_attrs. This saves several bytes.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: Keep parent bridge active when probing device

This patch fixes the following bug:

http://marc.info/?l=linux-pci&m=134329923124234&w=2

The root cause of the bug is as follow.

If a device is not bound with the corresponding driver, the device
runtime PM will be disabled and the device will be put into suspended
state. So that, the bridge/PCIe port connected to it may be put into
suspended and low power state. When do probing for the device later,
because the bridge/PCIe port connected to it is in low power state,
the IO access to device may fail.

To solve the issue, the bridge/PCIe port connected to the device is
put into active state before probing.

Reported-by: Bjorn Mork <bjorn@mork.no>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>

PCI: EHCI: Fix crash during hibernation on ASUS computers

Commit dbf0e4c (PCI: EHCI: fix crash during suspend on ASUS
computers) added a workaround for an ASUS suspend issue related to
USB EHCI and a bug in a number of ASUS BIOSes that attempt to shut
down the EHCI controller during system suspend if its PCI command
register doesn't contain 0 at that time.

It turns out that the same workaround is necessary in the analogous
hibernation code path, so add it.

References: https://bugzilla.kernel.org/show_bug.cgi?id=45811
Reported-and-tested-by: Oleksij Rempel <bug-track@fisher-privat.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org

PCI: EHCI: fix crash during suspend on ASUS computers

Quite a few ASUS computers experience a nasty problem, related to the
EHCI controllers, when going into system suspend. It was observed
that the problem didn't occur if the controllers were not put into the
D3 power state before starting the suspend, and commit
151b61284776be2d6f02d48c23c3625678960b97 (USB: EHCI: fix crash during
suspend on ASUS computers) was created to do this.

It turned out this approach messed up other computers that didn't have
the problem -- it prevented USB wakeup from working. Consequently
commit c2fb8a3fa25513de8fedb38509b1f15a5bbee47b (USB: add
NO_D3_DURING_SLEEP flag and revert 151b61284776be2) was merged; it
reverted the earlier commit and added a whitelist of known good board
names.

Now we know the actual cause of the problem. Thanks to AceLan Kao for
tracking it down.

According to him, an engineer at ASUS explained that some of their
BIOSes contain a bug that was added in an attempt to work around a
problem in early versions of Windows. When the computer goes into S3
suspend, the BIOS tries to verify that the EHCI controllers were first
quiesced by the OS. Nothing's wrong with this, but the BIOS does it
by checking that the PCI COMMAND registers contain 0 without checking
the controllers' power state. If the register isn't 0, the BIOS
assumes the controller needs to be quiesced and tries to do so. This
involves making various MMIO accesses to the controller, which don't
work very well if the controller is already in D3. The end result is
a system hang or memory corruption.

Since the value in the PCI COMMAND register doesn't matter once the
controller has been suspended, and since the value will be restored
anyway when the controller is resumed, we can work around the BIOS bug
simply by setting the register to 0 during system suspend. This patch
(as1590) does so and also reverts the second commit mentioned above,
which is now unnecessary.

In theory we could do this for every PCI device. However to avoid
introducing new problems, the patch restricts itself to EHCI host
controllers.

Finally the affected systems can suspend with USB wakeup working
properly.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=37632
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=42728
Based-on-patch-by: AceLan Kao <acelan.kao@canonical.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Dâniel Fraga <fragabr@gmail.com>
Tested-by: Javier Marcet <jmarcet@gmail.com>
Tested-by: Andrey Rahmatullin <wrar@wrar.name>
Tested-by: Oleksij Rempel <bug-track@fisher-privat.net>
Tested-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Cc: stable <stable@vger.kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PCI / PM: restore the original behavior of pci_set_power_state()

Commit cc2893b6 (PCI: Ensure we re-enable devices on resume)
addressed the problem with USB not being powered after resume on
recent Lenovo machines, but it did that in a suboptimal way.
Namely, it should have changed the relevant code paths only,
which are pci_pm_resume_noirq() and pci_pm_restore_noirq() supposed
to restore the device's power and standard configuration registers
after system resume from suspend or hibernation. Instead, however,
it modified pci_set_power_state() which is executed in several
other situations too. That resulted in some undesirable effects,
like attempting to change a device's power state in the same way
multiple times in a row (up to as many as 4 times in a row in the
snd_hda_intel driver).

Fix the bug addressed by commit cc2893b6 in an alternative way,
by forcibly powering up all devices in pci_pm_default_resume_early(),
which is called by pci_pm_resume_noirq() and pci_pm_restore_noirq()
to restore the device's power and standard configuration registers,
and modifying pci_pm_runtime_resume() to avoid the forcible power-up
if not necessary. Then, revert the changes made by commit cc2893b6
to make the confusion introduced by it go away.

Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/PM: add PCIe runtime D3cold support

This patch adds runtime D3cold support and corresponding ACPI platform
support. This patch only enables runtime D3cold support; it does not
enable D3cold support during system suspend/hibernate.

D3cold is the deepest power saving state for a PCIe device, where its main
power is removed. While it is in D3cold, you can't access the device at
all, not even its configuration space (which is still accessible in D3hot).
Therefore the PCI PM registers can not be used to transition into/out of
the D3cold state; that must be done by platform logic such as ACPI _PR3.

To support wakeup from D3cold, a system may provide auxiliary power, which
allows a device to request wakeup using a Beacon or the sideband WAKE#
signal. WAKE# is usually connected to platform logic such as ACPI GPE.
This is quite different from other power saving states, where devices
request wakeup via a PME message on the PCIe link.

Some devices, such as those in plug-in slots, have no direct platform
logic. For example, there is usually no ACPI _PR3 for them. D3cold
support for these devices can be done via the PCIe Downstream Port leading
to the device. When the PCIe port is powered on/off, the device is powered
on/off too. Wakeup events from the device will be notified to the
corresponding PCIe port.

For more information about PCIe D3cold and corresponding ACPI support,
please refer to:

- PCI Express Base Specification Revision 2.0
- Advanced Configuration and Power Interface Specification Revision 5.0

[bhelgaas: changelog]
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Originally-by: Zheng Yan <zheng.z.yan@intel.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: disable Bus Master on PCI device shutdown

Disable Bus Master bit on the device in pci_device_shutdown() to ensure PCI
devices do not continue to DMA data after shutdown. This can cause memory
corruption in case of a kexec where the current kernel shuts down and
transfers control to a new kernel while a PCI device continues to DMA to
memory that does not belong to it any more in the new kernel.

I have tested this code on two laptops, two workstations and a 16-socket
server. kexec worked correctly on all of them.

Signed-off-by: Khalid Aziz <khalid.aziz@hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI / PM: Disable wakeup during shutdown for devices not enabled to wake up

If a PCI device is enabled to generate wakeup signals (PME) when put
into a low-power state by runtime PM, it will be still enabled to
generate those signals after the system shutdown, unless its driver's
.shutdown() callback takes care of the wakeup signals generation
setting. Moreover, there are devices that are not enabled to wake
up the system and that are configured by runtime PM to generate
wakeup signals so that (runtime) remote wakeup works with them.
Those devices should be reconfigured during system shutdown so that
they don't generate wakeup signals, but at least some drivers don't
do that. However, that very well may be done by the PCI core so
that drivers don't have to worry about it. For this reason, modify
pci_device_shutdown() to disable the generation of wakeup events for
devices not supposed to wake up the system.

References: https://bugzilla.kernel.org/show_bug.cgi?id=37952
Reported-and-tested-by: Kamil Iskra <kamil.54002@iskra.name>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

USB/PCI/PCMCIA: Clean up new_id and remove_id sysfs attribute routines

This patch (as1514) cleans up some places where new_id and remove_id
sysfs attributes are created and deleted. Handling both attributes in
a single routine rather than a pair of routines makes the code
smaller. It also prevents certain kinds of errors, like one we
currently have in the USB subsystem: The removeid attribute is often
created even when newid isn't (because the driver's no_dynamid_id flag
is set).

In the case of the PCMCIA subsystem, the newid attribute is created
but never explicitly deleted. The patch adds a deletion routine.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Dynamic ID addition doesn't need get_driver()

As part of the removal of get_driver()/put_driver(), this patch
(as1511) changes all the places that add dynamic IDs for drivers.
Since these additions are done by writing to the drivers' sysfs
attribute files, and the attributes are removed when the drivers are
unregistered, there is no reason to take an extra reference to the
drivers.

The one exception is the pci-stub driver, which calls pci_add_dynid()
as part of its registration. But again, there's no reason to take an
extra reference here, because the driver can't be unloaded while it is
being registered.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: Jiri Kosina <jkosina@suse.cz>
CC: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: pci_has_legacy_pm_support add driver and device to WARN

Include the driver name and device in warning when a pci driver
supports both legacy pm and new framework as just the stack trace
gives no way to identify the driver.

Signed-off-by: David Fries <David@Fries.net>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI / PM: Detect early wakeup in pci_pm_prepare()

A subsequent patch is going to move the invocation of
pm_runtime_barrier() from dpm_prepare() to __device_suspend().
Consequently, early wakeup events resulting from runtime resume
requests for wakeup devices queued up right before system suspend
will only be detected after all of the subsystem-level .prepare()
callbacks have run. However, the PCI bus type calls
pm_runtime_get_sync() from its pci_pm_prepare() callback routine,
so it would destroy the early wakeup events information regarding PCI
devices. To prevent this from happening add an early wakeup
detection mechanism, analogous to the one currently in dpm_prepare(),
to pci_pm_prepare().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI / PM: Block races between runtime PM and system sleep

After commit e8665002477f0278f84f898145b1f141ba26ee26
(PM: Allow pm_runtime_suspend() to succeed during system suspend) it
is possible that a device resumed by the pm_runtime_resume(dev) in
pci_pm_prepare() will be suspended immediately from a work item,
timer function or otherwise, defeating the very purpose of calling
pm_runtime_resume(dev) from there. To prevent that from happening
it is necessary to increment the runtime PM usage counter of the
device by replacing pm_runtime_resume() with pm_runtime_get_sync().
Moreover, the incremented runtime PM usage counter has to be
decremented by the corresponding pci_pm_complete(), via
pm_runtime_put_sync().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKS

Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose. However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation. Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.

To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>

PM: Remove CONFIG_PM_OPS

After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP ||
CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be
replaced with CONFIG_PM.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PCI: fix __pci_device_probe kernel-doc warning

Fix kernel-doc warning for __pci_device_probe():

Warning(drivers/pci/pci-driver.c:341): missing initial short description on line:
* __pci_device_probe()

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: make pci_restore_state return void

pci_restore_state only ever returns 0, thus there is no benefit in
having it return any value. Also, a large majority of the callers do
not check the return code of pci_restore_state. Make the
pci_restore_state a void return and avoid the overhead.

Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Jon Mason <jon.mason@exar.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: change device runtime PM settings for probe and remove

This patch (as1388) changes the way the PCI core handles runtime PM
settings when probing or unbinding drivers. Now the core will make
sure the device is enabled for runtime PM, with a usage count >= 1,
when a driver is probed. It does the same when calling a driver's
remove method.

If the driver wants to use runtime PM, all it has to do is call
pm_runtime_pu_noidle() near the end of its probe routine (to cancel
the core's usage increment) and pm_runtime_get_noresume() near the
start of its remove routine (to restore the usage count). It does not
need to mess around with setting the runtime state to enabled,
disabled, active, or suspended.

The patch updates e1000e and r8169, the only PCI drivers that already
use the existing runtime PM interface.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Run-time callbacks for PCI bus type

Introduce run-time PM callbacks for the PCI bus type. Make the new
callbacks work in analogy with the existing system sleep PM
callbacks, so that the drivers already converted to struct dev_pm_ops
can use their suspend and resume routines for run-time PM without
modifications.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: Clear saved_state after the state has been restored

Some PCI devices fail if their standard configuration registers are
restored twice in a row. Prevent this from happening by making
pci_restore_state() clear the saved_state flag of the device right
after the device's standard configuration registers have been
populated with the previously saved values.

Simplify PCI PM callbacks by removing the direct clearing of
state_saved from them, as it shouldn't be necessary any more (except
in pci_pm_thaw(), where it has to be cleared, so that the values saved
during the "freeze" phase of hibernation are not used later by mistake).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Return error codes from pci_pm_resume()

Currently pci_pm_resume() always returns 0, which makes the error
variable defined in there a bit pointless. Make pci_pm_resume()
return error codes obtained from drivers' callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: separate out pci_add_dynid()

Separate out pci_add_dynid() from store_new_id() and export it so that
in-kernel code can add PCI IDs dynamically. As the function will be
available regardless of HOTPLUG, put it and pull pci_free_dynids()
outside of CONFIG_HOTPLUG.

This will be used by pci-stub to initialize initial IDs via module
param.

While at it, remove bogus get_driver() failure check.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: check saved state before restore

Without the check, the config space may be filled with zeros. Though
the driver should try to avoid call restoring before saving, but the
pci layer also should check this.

Also removes the existing check in pci_restore_standard_config, since
it's superfluous with the new check in restore_state.

Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Driver Core: Make PM operations a const pointer

They are not supposed to be modified by drivers, so make them const.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Driver Core: Make PM operations a const pointer

They are not supposed to be modified by drivers, so make them const.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PCI PM: Restore config spaces of all devices during early resume

At present the configuration spaces of PCI devices that have no
drivers or no PM support in the drivers (either legacy or through a
pm object) are not saved during suspend and, consequently, they are
not restored during resume. This generally may lead to the state of
the system being slightly inconsistent after the resume, so it's
better to save and restore the configuration spaces of these devices
as well.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Put devices into low power states during late suspend (rev. 2)

Once we have allowed timer interrupts to be enabled during the late
phase of suspending devices, we are now able to use the generic
pci_set_power_state() to put PCI devices into low power states at
that time. We can also use some related platform callbacks, like the
ones preparing devices for wake-up, during the late suspend.

Doing this will allow us to avoid the race condition where a device
using shared interrupts is put into a low power state with interrupts
enabled and then an interrupt (for another device) comes in and
confuses its driver. At the same time, devices that don't support
the native PCI PM or that require some additional, platform-specific
operations to be carried out to put them into low power states will
be handled as appropriate.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Move pci_restore_standard_config to pci-driver.c

Move pci_restore_standard_config() from pci.c to pci-driver.c and
make it static.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Consistently use variable name "error" for pm call return values

I noticed two functions use a variable "i" to store the return value of PM
function calls while the rest of the file uses "error". As "i" normally
indicates a counter of some sort it seems better to keep this consistent.

Signed-off-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PCI: Introduce /sys/bus/pci/rescan

This interface allows the user to force a rescan of all PCI buses
in system, and rediscover devices that have been removed earlier.

pci_bus_attrs implementation from Trent Piepho.

Thanks to Vegard Nossum for discovering locking issues with the
sysfs interface.

Cc: Trent Piepho <xyzzy@speakeasy.org>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: add remove_id sysfs entry

This adds a remove_id sysfs entry to allow users of new_id to later
remove the added dynid. One use case is management tools that want to
dynamically bind/unbind devices to pci-stub driver while devices are
assigned to KVM guests. Rather than having to track which driver was
originally bound to the driver, a mangement tool can simply:

Guest uses device

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

cpumask: replace node_to_cpumask with cpumask_of_node.

Impact: cleanup

node_to_cpumask (and the blecherous node_to_cpumask_ptr which
contained a declaration) are replaced now everyone implements
cpumask_of_node.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

PCI PM: make the PM core more careful with drivers using the new PM framework

Currently, the PM core always attempts to manage devices with drivers
that use the new PM framework. In particular, it attempts to disable
the devices (which is unnecessary), to save their state (which may be
undesirable if the driver has done that already) and to put them into
low power states (again, this may be undesirable if the driver has
already put the device into a low power state). That need not be
the right thing to do, so make the core be more careful in this
respect.

Generally, there are the following categories of devices to consider:
* bridge devices without drivers
* non-bridge devices without drivers
* bridge devices with drivers
* non-bridge devices with drivers
and each of them should be handled differently.

For bridge devices without drivers the PCI PM core will save their
state on suspend and restore it (early) during resume, after putting
them into D0 if necessary. It will not attempt to do anything else
to these devices.

For non-bridge devices without drivers the PCI PM core will disable
them and save their state on suspend. During resume, it will put
them into D0, if necessary, restore their state (early) and reenable
them.

For bridge devices with drivers the PCI PM core will only save
their state on suspend if the driver hasn't done that already.
Still, the core will restore their state (early) during resume,
after putting them into D0, if necessary.

For non-bridge devices with drivers the PCI PM core will only save
their state on suspend if the driver hasn't done that already. Also,
if the state of the device hasn't been saved by the driver, the core
will attempt to put the device into a low power state. During
resume the core will restore the state of the device (early), after
putting it into D0, if necessary.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Do not disable and enable bridges during suspend-resume

It is a mistake to disable and enable PCI bridges and PCI Express
ports during suspend-resume, at least at the time when it is
currently done. Disabling them may lead to problems with accessing
devices behind them and they should be automatically enabled when
their standard config spaces are restored. Fix this by not attempting
to disable bridges during suspend and enable them during resume.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Fix saving of device state in pci_legacy_suspend

Make pci_legacy_suspend() save the state of the device if it is
in PCI_UNKNOWN after its suspend callback has run and warn only if
the power state of the device has been changed by its suspend
callback.

Also, use WARN_ONCE(), which is more useful, in pci_legacy_suspend(),
so that the name of the offending function is printed.

Additionally, remove the unnecessary line of code setting
pci_dev->state_saved.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Fix handling of devices without drivers

Suspend to RAM is reported to break on some machines as a result of
attempting to put one of driverless PCI devices into a low power
state. Avoid that by not attepmting to power manage driverless
devices during suspend.

Fix up pci_pm_poweroff() after a previous incomplete fix for the same
thing during hibernation.

This patch is reported to fix the regression from 2.6.28 tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=12605

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: Eric Sesterhenn <snakebyte@gmx.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Fix hibernation breakage on EeePC 701

Hibernation breaks on EeePC 701 as a result of attempting to put one
of its (driverless) devices into a low power state. Avoid that by
not attepmting to power manage driverless devices during hibernation.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-and-tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Fix suspend error paths and testing facility breakage

If one of device drivers refuses to suspend by returning error code
from its ->suspend() callback, the devices that have already been
suspended are resumed by executing their drivers' ->resume()
callbacks. Some of these callbacks expect the device's
configuration space to be restored if the device has been put into
D3 before they are called. Unfortunately, this mechanism has been
broken by recent changes moving the restoration of config spaces
of some devices (most importantly, USB controllers and HDA Intel)
into the resume callbacks executed with interrupts off. Obviously,
these callbacks are not invoked in the suspend error path and, as a
result, the system cannot be successfully brought back into the
working state in case of a suspend error. The same thing happens
in the hibernation error path right before putting the system into
S4.

Similarly, the suspend testing facility associated with the
/sys/power/pm_test file is broken, because it uses the very same
mechanism that is used in the suspend and hibernation error paths.

Fix the breakage by making the PCI core restore the configuration
spaces of PCI devices that haven't been restored already before
pci_pm_resume() is called for those devices by the PM core.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Restore standard config registers of all devices early

There is a problem in our handling of suspend-resume of PCI devices that
many of them have their standard config registers restored with
interrupts enabled and they are put into the full power state with
interrupts enabled as well. This may lead to the following scenario:
* an interrupt vector is shared between two or more devices
* one device is resumed earlier and generates an interrupt
* the interrupt handler of another device tries to handle it and
attempts to access the device the config space of which hasn't been
restored yet and/or which still is in a low power state
* the system crashes as a result

To prevent this from happening we should restore the standard
configuration registers of all devices with interrupts disabled and we
should put them into the D0 power state right after that.
Unfortunately, this cannot be done using the existing
pci_set_power_state(), because it can sleep. Also, to do it we have to
make sure that the config spaces of all devices were actually saved
during suspend.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Put PM callbacks in the order of execution

Put PM callbacks in drivers/pci/pci-driver.c in the order in which
they are executed which makes it much easier to follow the code.

No functional changes should result from this.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Run default PM callbacks for all devices using new framework

It should be quite clear that it generally makes sense to execute
the default PM callbacks (ie. the callbacks used for handling
suspend, hibernation and resume of PCI devices without drivers) for
all devices. Of course, the drivers that provide legacy PCI PM
support (ie. the ->suspend, ->suspend_late, ->resume_early
or ->resume hooks in the pci_driver structure), carry out these
operations too, so we can't do it for devices with such drivers.
Still, we can make the default PM callbacks run for devices with
drivers using the new framework (ie. implement the pm object), since
there are no such drivers at the moment.

This also simplifies the code and makes it smaller.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Call pci_fixup_device from legacy routines

The size of drivers/pci/pci-driver.c can be reduced quite a bit
if pci_fixup_device() is called from the legacy PM callbacks, so make
it happen.

No functional changes should result from this.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Rearrange code in pci-driver.c

Rename two functions and rearrange code in drivers/pci/pci-driver.c
so that it's easier to follow. In particular, separate invocations
of the legacy callbacks from the rest of the new callbacks' code.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Avoid touching devices behind bridges in unknown state

It generally is better to avoid accessing devices behind bridges that
may not be in the D0 power state, because in that case the bridges'
secondary buses may not be accessible. For this reason, during the
early phase of resume (ie. with interrupts disabled), before
restoring the standard config registers of a device, check the power
state of the bridge the device is behind and postpone the restoration
of the device's config space, as well as any other operations that
would involve accessing the device, if that state is not D0.

In such cases the restoration of the device's config space will be
retried during the "normal" phase of resume (ie. with interrupts
enabled), so that the bridge can be put into D0 before that happens.

Also, save standard configuration registers of PCI devices during the
"normal" phase of suspend (ie. with interrupts enabled), so that the
bridges the devices are behind can be put into low power states (we
don't put bridges into low power states at the moment, but we may
want to do it in the future and it seems reasonable to design for
that).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Move pci_has_legacy_pm_support

Move pci_has_legacy_pm_support() closer to the functions that
call it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Power-manage devices without drivers during suspend-resume

PCI devices without drivers can be put into low power states during
suspend with the help of pci_prepare_to_sleep() and prevented from
generating wake-up events during resume with the help of
pci_enable_wake(). However, it's better not to put bridges into
low power states during suspend, because that might result in entire
bus segments being powered off.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Add suspend counterpart of pci_reenable_device

PCI devices without drivers are not disabled during suspend and
hibernation, but they are enabled during resume, with the help of
pci_reenable_device(), so there is an unbalanced execution of
pcibios_enable_device() in the resume code path.

To correct this introduce function pci_disable_enabled_device()
that will disable the argument device, if it is enabled when the
function is being run, without updating the device's pci_dev
structure and use it in the suspend code path to balance the
pci_reenable_device() executed during resume.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: Fix poweroff and restore callbacks

pci_fixup_device() is called too early in pci_pm_poweroff() and too
late in pci_pm_restore(). Moreover, pci_pm_restore_noirq() calls
pci_fixup_device() twice and in a wrong way. Fix that.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: work_on_cpu: use in drivers/pci/pci-driver.c

This uses work_on_cpu(), rather than altering the cpumask of the
thread which we happen to be.

Note the cleanups:

1) I've removed the CONFIG_NUMA test, since dev_to_node() returns -1
for !CONFIG_NUMA anyway and the compiler will eliminate it.

2) No need to reset mempolicy to default (a bad idea anyway) since
work_on_cpu is run from a workqueue.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: allow pci driver to support only dynids

commit b41d6cf38e27 (PCI: Check dynids driver_data value for validity)
requires all drivers to include an id table to try and match
driver_data. Before validating driver_data check driver has an id
table.

Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Milton Miller <miltonm@bga.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: Rework default handling of suspend and resume

Rework the handling of suspend and resume of PCI devices which have
no drivers or the drivers of which do not provide any suspend-resume
callbacks in such a way that their standard PCI configuration
registers will be saved and restored with interrupts disabled. This
should prevent such devices, including PCI bridges, from being
resumed too late to be able to function correctly during the resume
of the other PCI devices that may depend on them.

Also, to remove one possible source of future confusion, drop the
default handling of suspend and resume for PCI devices with drivers
providing the 'pm' object introduced by the new suspend-resume
framework (there are no such PCI drivers at the moment).

This patch addresses the regression from 2.6.26 tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=12121 .

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PM: Simplify the new suspend/hibernation framework for devices

PM: Simplify the new suspend/hibernation framework for devices

Following the discussion at the Kernel Summit, simplify the new
device PM framework by merging 'struct pm_ops' and
'struct pm_ext_ops' and removing pointers to 'struct pm_ext_ops'
from 'struct platform_driver' and 'struct pci_driver'.

After this change, the suspend/hibernation callbacks will only
reside in 'struct device_driver' as well as at the bus type/
device class/device type level. Accordingly, PCI and platform
device drivers are now expected to put their suspend/hibernation
callbacks into the 'struct device_driver' embedded in
'struct pci_driver' or 'struct platform_driver', respectively.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: Check dynids driver_data value for validity

Only accept dynids whose driver_data value matches one of the driver's
pci_driver_id entries. This prevents the user from accidentally passing
values the drivers do not expect.

Cc: Milton Miller <miltonm@bga.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: remove dynids.use_driver_data

The driver flag dynids.use_driver_data is almost consistently not set,
and causes more problems than it solves. It was initially intended as a
flag to indicate whether a driver's usage of driver_data had been
carefully inspected and was ready for values from userspace. That audit
was never done, so most drivers just get a 0 for driver_data when new
IDs are added from userspace via sysfs. So remove the flag, allowing
drivers to see the data directly (a followon patch validates the passed
driver_data value against what the drivers expect).

Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: implement new suspend/resume callbacks

Implement new suspend and hibernation callbacks for the PCI bus type.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Suspend/Resume bug in PCI layer wrt quirks

Some quirks should be called with interrupt disabled, we can't directly
call them in .resume_early. Also the patch introduces
pci_fixup_resume_early and pci_fixup_suspend, which matches current
device core callbacks (.suspend/.resume_early).

TBD: Somebody knows why we need quirk resume should double check if a
quirk should be called in resume or resume_early. I changed some per my
understanding, but can't make sure I fixed all.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: use dev_to_node in pci_call_probe

to make sure get one online node.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2

[PATCH 2/2] pci/irq: let pci_device_shutdown to call pci_msi_shutdown v2

this change

| commit 23a274c8a5adafc74a66f16988776fc7dd6f6e51
| Author: Prakash, Sathya <sathya.prakash@lsi.com>
| Date: Fri Mar 7 15:53:21 2008 +0530
|
| [SCSI] mpt fusion: Enable MSI by default for SAS controllers
|
| This patch modifies the driver to enable MSI by default for all SAS chips.
|
| Signed-off-by: Sathya Prakash <sathya.prakash@lsi.com>
| Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
|
Causes the kexec of a RHEL 5.1 kernel to fail.

root casue: the rhel 5.1 kernel still uses INTx emulation. and
mptscsih_shutdown doesn't call pci_disable_msi to reenable INTx on kexec path

So call pci_msi_shutdown in the shutdown path to do the same thing to msix

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@hobbes.lan>

generic: use new set_cpus_allowed_ptr function

* Use new set_cpus_allowed_ptr() function added by previous patch,
which instead of passing the "newly allowed cpus" cpumask_t arg
by value, pass it by pointer:

-int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
+int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask)

* Modify CPU_MASK_ALL

Depends on:
[sched-devel]: sched: add new set_cpus_allowed_ptr function

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

PCI: Mem Policy: fix mempolicy usage in pci driver

In an attempt to ensure memory allocation from the local node, the pci
driver temporarily replaces the current task's memory policy with the
system default policy. Trying to be a good citizen, the driver then call's
mpol_get() on the new policy. When it's finished probing, it undoes the
'_get by calling mpol_free() [on the system default policy] and then
restores the current task's saved mempolicy.

A couple of issues here:

1) it's never necessary to set a task's mempolicy to the
system default policy in order to get system default
allocation behavior. Simply set the current task's
mempolicy to NULL and allocations will fall back to
system default policy.

2) we should never [need to] call mpol_free() on the system
default policy. [I plan on trapping this with a VM_BUG_ON()
in a subsequent patch.]

This patch removes the calls to mpol_get() and mpol_free()
and uses NULL for the temporary task mempolicy to effect
default allocation behavior.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: remove foolish code from pci-driver.c

The PCI bus should not be trying to declare its own attribute type.
Especially as this code could never ever be called because the driver
core overwrites the driver kobject type to be its own internal type.
Delete all of this code as it was never being used and is not correct.

Also update my copyright on the file while I'm touching things there.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: use proper call to driver_create_file

Don't try to call the "raw" sysfs_create_file when we already have a
helper function to do this kind of work for us.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: make pci_match_device() static

pci_match_device() no longer has any other users.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: Fix incorrect argument order to list_add_tail() in PCI dynamic ID code

The code for dynamically assigning new ids to PCI drivers,
store_new_id(), calls list_add_tail() with the list head and new node
arguments in reversed order.

The result is that every new id written essentially overwrites the
previous list of ids.

Caught with the help of Rusty's "horribly bad" list_node patch:
http://lkml.org/lkml/2007/6/10/10

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: change add_uevent_var to use a struct

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

pci: rename __pci_reenable_device() to pci_reenable_device()

Rename __pci_reenable_device() to pci_reenable_device().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

Fix more "deprecated" spellos.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

PCI: remove the broken PCI_MULTITHREAD_PROBE option

This patch removes the PCI_MULTITHREAD_PROBE option that had already
been marked as broken.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: Require vendor and device for new_id

Currently, there is no minimum number of fields required when adding
a new device ID to a PCI driver through the new_id sysfs file. It is
possible to add a new ID with only the vendor ID set, causing the
driver to attempt to attach to all PCI devices from that vendor. This
has been reported to happen accidentally:
http://lists.lm-sensors.org/pipermail/lm-sensors/2007-March/019366.html
It is even possible to not even set the vendor ID field, causing the
driver to attempt to attach to _all_ the PCI devices.

This sounds dangerous and I fail to see any valid use of this
"feature". Thus I suggest that we now require at least the first two
fields (vendor ID and device ID) to be set. For what it's worth, this
is what the USB subsystem does.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: per-subsystem multithreaded probing

Make multithreaded probing work per subsystem instead of per driver.

It doesn't make much sense to probe the same device for multiple drivers in
parallel (after all, only one driver can bind to the device). Instead, create
a probing thread for each device that probes the drivers one after another.
Also make the decision to use multi-threaded probe per bus instead of per
device and adapt the pci code.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI/sysfs/kobject kernel-doc fixes

Fix kernel-doc warnings in PCI, sysfs, and kobject files.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI : add extremely specialized __pci_reenable_device for default resume

Original patch was posted as "PCI : Move pci_fixup_device and is_enabled".
This 3 of 3 patches does:

- add __pci_reenable_device
(recover former change of 1st patch)

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI : remove too specialized __pci_enable_device for default resume

Original patch was posted as "PCI : Move pci_fixup_device and is_enabled".
This 1 of 3 patches does:

- reverts small part of Inaky's patch
(remove __pci_enable_device)
This change will be recovered by 3rd patch.

- temporarily remove pci_fixup_device.
This change will be recovered by 2nd patch.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: add the sysfs driver name to all modules

This adds the module name to all PCI drivers, if they are built into the
kernel or not. It will show up in /sys/modules/MODULE_NAME/drivers/

It also fixes up the IDE core, which was calling __pci_register_driver()
directly.

Cc: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: fix pci-driver kernel-doc

Function short description should be on only one line.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: Fix multiple problems with VIA hardware

This patch is designed to fix:
- Disk eating corruptor on KT7 after resume from RAM
- VIA IRQ handling
- VIA fixups for bus lockups after resume from RAM

The core of this is to add a table of resume fixups run at resume time.
We need to do this for a variety of boards and features, but particularly
we need to do this to get various critical VIA fixups done on resume.

The second part of the problem is to handle VIA IRQ number rules which
are a bit odd and need special handling for PIC interrupts. Various
patches broke various boxes and while this one may not be perfect
(hopefully it is) it ensures the workaround is applied to the right
devices only.

From: Jean Delvare <khali@linux-fr.org>

Now that PCI quirks are replayed on software resume, we can safely
re-enable the Asus SMBus unhiding quirk even when software suspend support
is enabled.

[akpm@osdl.org: fix const warning]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: use /sys/bus/pci/drivers/<driver>/new_id first

Unfortunately, the .../new_id feature does not work with the 8250_pci
driver.

The reason for this comes down to the way .../new_id is implemented.
When PCI tries to match a driver to a device, it checks the modules
static device ID tables _before_ checking the dynamic new_id tables.

When a driver is capable of matching by ID, and falls back to matching
by class (as 8250_pci does), this makes it absolutely impossible to
specify a board by ID, and as such the correct driver_data value to
use with it.

Let's say you have a serial board with vendor 0x1234 and device 0x5678.
It's class is set to PCI_CLASS_COMMUNICATION_SERIAL.

On boot, this card is matched to the 8250_pci driver, which tries to
probe it because it matched using the class entry. The driver finds
that it is unable to automatically detect the correct settings to use,
so it returns -ENODEV.

You know that the information the driver needs is to match this card
using a device_data value of '7'. So you echo 1234 5678 0 0 0 0 7
into new_id.

The kernel attempts to re-bind 8250_pci to this device. However,
because it scans the PCI driver tables, it _again_ matches the class
entry which has the wrong device_data. It fails.

End of story. You can't support the card without rebuilding the
kernel (or writing a specific PCI probe module to support it.)

So, can we make new_id override the driver-internal PCI ID tables?
IOW, like this:


From: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: switch pci_{enable,disable}_device() to be nestable

Changes the pci_{enable,disable}_device() functions to work in a
nested basis, so that eg, three calls to enable_device() require three
calls to disable_device().

The reason for this is to simplify PCI drivers for
multi-interface/capability devices. These are devices that cram more
than one interface in a single function. A relevant example of that is
the Wireless [USB] Host Controller Interface (similar to EHCI) [see
http://www.intel.com/technology/comms/wusb/whci.htm].

In these kind of devices, multiple interfaces are accessed through a
single bar and IRQ line. For that, the drivers map only the smallest
area of the bar to access their register banks and use shared IRQ
handlers.

However, because the order at which those drivers load cannot be known
ahead of time, the sequence in which the calls to pci_enable_device()
and pci_disable_device() cannot be predicted. Thus:

1. driverA starts pci_enable_device()
2. driverB starts pci_enable_device()
3. driverA shutdown pci_disable_device()
4. driverB shutdown pci_disable_device()

between steps 3 and 4, driver B would loose access to it's device,
even if it didn't intend to.

By using this modification, the device won't be disabled until all the
callers to enable() have called disable().

This is implemented by replacing 'struct pci_dev->is_enabled' from a
bitfield to an atomic use count. Each caller to enable increments it,
each caller to disable decrements it. When the count increments from 0
to 1, __pci_enable_device() is called to actually enable the
device. When it drops to zero, pci_disable_device() actually does the
disabling.

We keep the backend __pci_enable_device() for pci_default_resume() to
use and also change the sysfs method implementation, so that userspace
enabling/disabling the device doesn't disable it one time too much.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

pci: fix __pci_register_driver error handling

__pci_register_driver() error path forgot to unwind.
driver_unregister() needs to be called when pci_create_newid_file() failed.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: reset pci device state to unknown state for resume

Considering below scenario:
1.Unload a PCI device's driver, the device ->current remains in PCI_D0.
2.Do suspend/resume circle. After that, BIOS puts the device to D3.
3.Reload the device driver. The calling pci_set_power_state in the
driver can't change the state to D0, as set_power_state thinks the
device is already in D0.

A bug is reported at http://bugzilla.kernel.org/show_bug.cgi?id=6024
Pat attached a patch at
http://marc.theaimsgroup.com/?l=linux-pci&m=114049761428561&w=2 for this
issue, but it's lost. As pci_set_power_state can handle D3 -> D0
correctly (restore config space), I simplified Patrick's patch.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: Multiprobe sanitizer

There are numerous drivers that can use multithreaded probing but having
some kind of global flag as the way to control this makes migration to
threaded probing hard and since it enables it everywhere and is almost
as likely to cause serious pain as holding a clog dance in a minefield.

If we have a pci_driver multithread_probe flag to inherit you can turn
it on for one driver at a time.

From playing so far however I think we need a different model at the
device layer which serializes until the called probe function says "ok
you can start another one now". That would need some kind of flag and
semaphore plus a helper function.

Anyway in the absence of that this is a starting point to usefully play
with this stuff

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: fix __must_check warnings

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: enable driver multi-threaded probe

This provides a build and run-time option to turn on multhreaded probe
for all PCI drivers. It can cause bad problems on multi-processor
machines that take a while to find their root disks, and play havoc on
machines that don't use persistant device names for block or network
devices.

But it can cause speedups on some machines, my tiny laptop's boot goes
up by 0.4 seconds, and my desktop boots up several seconds faster.

Use at your own risk!!!

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PM: no suspend_prepare() phase

Remove the new suspend_prepare() phase. It doesn't seem very usable,
has never been tested, doesn't address fault cleanup, and would need
a sibling resume_complete(); plus there are no real use cases. It
could be restored later if those issues get resolved.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Suspend changes for PCI core

Changes the PCI core to use the new suspend infrastructure changes.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI: kerneldoc correction in pci-driver

Removes an unused kerneldoc entry from pci_match_device and
put the others into correct order.

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI: Error handling on PCI device resume

We currently don't handle errors properly when resuming a PCI device:
* In pci_default_resume() we capture the error code returned by
pci_enable_device() but don't pass it up to the caller.
Introduced by commit 95a629657dbe28e44a312c47815b3dc3f1ce0970
* In pci_resume_device(), the errors possibly returned by the driver's
.resume method or by the generic pci_default_resume() function are
ignored.

This patch fixes both issues.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] pm: print name of failed suspend function

Print more diagnostic info to help identify the source of power management
suspend failures.

Example:

usb_hcd_pci_suspend(): pci_set_power_state+0x0/0x1af() returns -22
pci_device_suspend(): usb_hcd_pci_suspend+0x0/0x11b() returns -22
suspend_device(): pci_device_suspend+0x0/0x34() returns -22

Work-in-progress. It needs lots more suspend_report_result() calls sprinkled
everywhere.

Cc: Patrick Mochel <mochel@digitalimplant.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@suspend2.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI: kzalloc() conversion in drivers/pci

this patch converts drivers/pci to kzalloc usage.
Compile tested with allyes config.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI: Add pci_device_shutdown to pci_bus_type

The extra compatability code is not necessary. Any code still using
the old shutdown method will trigger the warning in driver_register()
instead.

Signed-off-by: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Add pci_bus_type probe and remove methods

Move the PCI bus device probe/remove methods to the bus_type
structure. We leave the shutdown method alone since there
are compatibility issues with that.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] driver core: replace "hotplug" by "uevent"

Leave the overloaded "hotplug" word to susbsystems which are handling
real devices. The driver core does not "plug" anything, it just exports
the state to userspace and generates events.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PCI: automatically set device_driver.owner

A nice feature of sysfs is that it can create the symlink from the
driver to the module that is contained in it.

It requires that the device_driver.owner is set, what is not the
case for many PCI drivers.

This patch allows pci_register_driver to set automatically the
device_driver.owner for any PCI driver.

Credits to Al Viro who suggested the method.

Signed-off-by: Laurent Riffard <laurent.riffard@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--

drivers/ide/setup-pci.c | 12 +++++++-----
drivers/pci/pci-driver.c | 9 +++++----
include/linux/ide.h | 3 ++-
include/linux/pci.h | 10 ++++++++--
4 files changed, 22 insertions(+), 12 deletions(-)

[PATCH] pci-driver: store_new_id() not inline

store_new_id() should not be (and cannot be) inline;
the function pointer is stored in a device_attribute table.

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] fix remaining missing includes

Fix more include file problems that surfaced since I submitted the previous
fix-missing-includes.patch. This should now allow not to include sched.h
from module.h, which is done by a followup patch.

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] fix missing includes

I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.

In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch. This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other. So if any
hunk rejects or gets in the way of other patches, just drop it. My scripts
will pick it up again in the next round.

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>