PCI/AER: Forward RCH downstream port-detected errors to the CXL.mem dev handler

In Restricted CXL Device (RCD) mode a CXL device is exposed as an
RCiEP, but CXL downstream and upstream ports are not enumerated and
not visible in the PCIe hierarchy. [1] Protocol and link errors from
these non-enumerated ports are signaled as internal AER errors, either
Uncorrectable Internal Error (UIE) or Corrected Internal Errors (CIE)
via an RCEC.

Restricted CXL host (RCH) downstream port-detected errors have the
Requester ID of the RCEC set in the RCEC's AER Error Source ID
register. A CXL handler must then inspect the error status in various
CXL registers residing in the dport's component register space (CXL
RAS capability) or the dport's RCRB (PCIe AER extended
capability). [2]

Errors showing up in the RCEC's error handler must be handled and
connected to the CXL subsystem. Implement this by forwarding the error
to all CXL devices below the RCEC. Since the entire CXL device is
controlled only using PCIe Configuration Space of device 0, function
0, only pass it there [3]. The error handling is limited to currently
supported devices with the Memory Device class code set (CXL Type 3
Device, PCI_CLASS_MEMORY_CXL, 502h), handle downstream port errors in
the device's cxl_pci driver. Support for other CXL Device Types
(e.g. a CXL.cache Device) can be added later.

To handle downstream port errors in addition to errors directed to the
CXL endpoint device, a handler must also inspect the CXL RAS and PCIe
AER capabilities of the CXL downstream port the device is connected
to.

Since CXL downstream port errors are signaled using internal errors,
the handler requires those errors to be unmasked. This is subject of a
follow-on patch.

The reason for choosing this implementation is that the AER service
driver claims the RCEC device, but does not allow it to register a
custom specific handler to support CXL. Connecting the RCEC hard-wired
with a CXL handler does not work, as the CXL subsystem might not be
present all the time. The alternative to add an implementation to the
portdrv to allow the registration of a custom RCEC error handler isn't
worth doing it as CXL would be its only user. Instead, just check for
an CXL RCEC and pass it down to the connected CXL device's error
handler. With this approach the code can entirely be implemented in
the PCIe AER driver and is independent of the CXL subsystem. The CXL
driver only provides the handler.

[1] CXL 3.0 spec: 9.11.8 CXL Devices Attached to an RCH
[2] CXL 3.0 spec, 12.2.1.1 RCH Downstream Port-detected Errors
[3] CXL 3.0 spec, 8.1.3 PCIe DVSEC for CXL Devices

Co-developed-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Terry Bowman <terry.bowman@amd.com>
Signed-off-by: Robert Richter <rrichter@amd.com>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-pci@vger.kernel.org
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20231018171713.1883517-18-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

PCI: pciehp: Enable by default if USB4 enabled

Thunderbolt/USB4 PCIe tunneling depends on native PCIe hotplug. Enable
pciehp by default if USB4 is enabled.

[bhelgaas: squash, update subject, commit logs, tidy whitespace]
Link: https://lore.kernel.org/r/20221115113857.35800-2-albert.zhou.50@gmail.com
Link: https://lore.kernel.org/r/20221115113857.35800-3-albert.zhou.50@gmail.com
Signed-off-by: Albert Zhou <albert.zhou.50@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PCI/AER: Update aer-inject URL

The link to the aer-inject referenced leads to an empty repo and seems no
longer used. Replace it with the link mentioned in
Documentation/PCI/pcieaer-howto.rst.

Link: https://lore.kernel.org/r/20220115104921.21606-1-yangyicong@hisilicon.com
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/LINK: Remove bandwidth notification

The PCIe Bandwidth Change Notification feature logs messages when the link
bandwidth changes. Some users have reported that these messages occur
often enough to significantly reduce NVMe performance. GPUs also seem to
generate these messages.

We don't know why the link bandwidth changes, but in the reported cases
there's no indication that it's caused by hardware failures.

Remove the bandwidth change notifications for now. Hopefully we can add
this back when we have a better understanding of why this happens and how
we can make the messages useful instead of overwhelming.

Link: https://lore.kernel.org/r/20200115221008.GA191037@google.com/
Link: https://lore.kernel.org/r/155605909349.3575.13433421148215616375.stgit@gimli.home/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206197
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Replace http:// links with https://

Replace http:// links with https:// links. This reduces the likelihood of
man-in-the-middle attacks when developers open these links.

Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.

[bhelgaas: also update samsung.com links, drop sourceforge link]
Link: https://lore.kernel.org/r/20200627103050.71712-1-grandmaster@al2klimov.de
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/AER: Don't select CONFIG_PCIEAER by default

PCIe Advanced Error Reporting (AER) is optional and there's no need for it
to be selected by default.

Remove the "default y" for CONFIG_PCIEAER.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Russell Currey <ruscur@russell.cc>
Cc: Sam Bobroff <sbobroff@linux.ibm.com>
Cc: Oliver O'Halloran <oohall@gmail.com>

PCI/DPC: Add Error Disconnect Recover (EDR) support

Error Disconnect Recover (EDR) is a feature that allows ACPI firmware to
notify OSPM that a device has been disconnected due to an error condition
(ACPI v6.3, sec 5.6.6). OSPM advertises its support for EDR on PCI devices
via _OSC (see [1], sec 4.5.1, table 4-4). The OSPM EDR notify handler
should invalidate software state associated with disconnected devices and
may attempt to recover them. OSPM communicates the status of recovery to
the firmware via _OST (sec 6.3.5.2).

For PCIe, firmware may use Downstream Port Containment (DPC) to support
EDR. Per [1], sec 4.5.1, table 4-6, even if firmware has retained control
of DPC, OSPM may read/write DPC control and status registers during the EDR
notification processing window, i.e., from the time it receives an EDR
notification until it clears the DPC Trigger Status.

Note that per [1], sec 4.5.1 and 4.5.2.4,

1. If the OS supports EDR, it should advertise that to firmware by
setting OSC_PCI_EDR_SUPPORT in _OSC Support.

2. If the OS sets OSC_PCI_EXPRESS_DPC_CONTROL in _OSC Control to request
control of the DPC capability, it must also set OSC_PCI_EDR_SUPPORT in
_OSC Support.

Add an EDR notify handler to attempt recovery.

[1] Downstream Port Containment Related Enhancements ECN, Jan 28, 2019,
affecting PCI Firmware Specification, Rev. 3.2
https://members.pcisig.com/wg/PCI-SIG/document/12888

[bhelgaas: squash add/enable patches into one]
Link: https://lore.kernel.org/r/90f91fe6d25c13f9d2255d2ce97ca15be307e1bb.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>

PCI/AER: Fix the broken interrupt injection

The AER error injection mechanism just blindly abuses generic_handle_irq()
which is really not meant for consumption by random drivers. The include of
linux/irq.h should have been a red flag in the first place. Driver code,
unless implementing interrupt chips or low level hypervisor functionality
has absolutely no business with that.

Invoking generic_handle_irq() from non interrupt handling context can have
nasty side effects at least on x86 due to the hardware trainwreck which
makes interrupt affinity changes a fragile beast. Sathyanarayanan triggered
a NULL pointer dereference in the low level APIC code that way. While the
particular pointer could be checked this would only paper over the issue
because there are other ways to trigger warnings or silently corrupt state.

Invoke the new irq_inject_interrupt() mechanism, which has the necessary
sanity checks in place and injects the interrupt via the irq_retrigger()
mechanism, which is at least halfways safe vs. the fragile x86 affinity
change mechanics.

It's safe on x86 as it does not corrupt state, but it still can cause a
premature completion of an interrupt affinity change causing the interrupt
line to become stale. Very unlikely, but possible.

For regular operations this is a non issue as AER error injection is meant
for debugging and testing and not for usage on production systems. People
using this should better know what they are doing.

Fixes: 390e2db82480 ("PCI/AER: Abstract AER interrupt handling")
Reported-by: sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lkml.kernel.org/r/20200306130624.098374457@linutronix.de

PCI/ASPM: Remove PCIEASPM_DEBUG Kconfig option and related code

Previously, CONFIG_PCIEASPM_DEBUG enabled "link_state" and "clk_ctl" sysfs
files that controlled ASPM. We believe these files were rarely if ever
used.

We recently added sysfs ASPM controls that are always present, so the debug
code is no longer needed. Removing this debug code has been discussed for
quite some time, see e.g. [0].

Remove PCIEASPM_DEBUG and the related code.

[0] https://lore.kernel.org/lkml/20180727202619.GD173328@bhelgaas-glaptop.roam.corp.google.com/
Link: https://lore.kernel.org/r/ec935d8e-c084-3938-f1d1-748617596b25@gmail.com
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Remove PCIe Kconfig dependencies on PCI

drivers/pci/pcie/Kconfig is only sourced by drivers/pci/Kconfig, and only
when PCI is defined, so there's no need to depend on PCI again. Remove the
unnecessary dependencies.

Link: https://lore.kernel.org/r/20191106222420.10216-5-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>

PCI/ASPM: Remove dependency on PCIEPORTBUS

The ASPM support does not depend on the portdrv, so remove the Kconfig
dependency.

Link: https://lore.kernel.org/r/20191106222420.10216-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>

PCI/PTM: Remove dependency on PCIEPORTBUS

The PTM support does not depend on the portdrv, so remove the Kconfig
dependency.

Link: https://lore.kernel.org/r/20191106222420.10216-3-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Cc: Jonathan Yong <jonathan.yong@intel.com>

PCI/LINK: Add Kconfig option (default off)

e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth
notification") added dmesg logging whenever a link changes speed or width
to a state that is considered degraded. Unfortunately, it cannot
differentiate signal integrity-related link changes from those
intentionally initiated by an endpoint driver, including drivers that may
live in userspace or VMs when making use of vfio-pci. Some GPU drivers
actively manage the link state to save power, which generates a stream of
messages like this:

vfio-pci 0000:07:00.0: 32.000 Gb/s available PCIe bandwidth, limited by 2.5 GT/s x16 link at 0000:00:02.0 (capable of 64.000 Gb/s with 5 GT/s x16 link)

Since we can't distinguish the intentional changes from the signal
integrity issues, leave the reporting turned off by default. Add a Kconfig
option to turn it on if desired.

Fixes: e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth notification")
Link: https://lore.kernel.org/linux-pci/20190501142942.26972-1-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Update PCIEPORTBUS Kconfig help text

The Virtual Channel service has been removed and Downstream Port
Containment has been added, so update the symbol description to be
consistent with the current code.

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

PCI: pcie: Remove redundant 'default n' from Kconfig

'default n' is the default value for any bool or tristate Kconfig setting
so there is no need to write it explicitly.

Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO is not
set' for visible symbols") the Kconfig behavior is the same regardless of
'default n' being present or not:

...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:

config FOO
bool

config FOO
bool
default n

With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI/AER: Use "PCI Express" consistently in Kconfig text

Use "PCI Express" consistently in Kconfig text. No functional change
intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>

PCI/AER: Hoist aerdrv.c, aer_inject.c up to drivers/pci/pcie/

Hoist aerdrv.c, aer_inject.c up to drivers/pci/pcie/ so they're next to
other PCIe service drivers. No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>

PCI/DPC: Enable DPC only if AER is available

The "Determination of DPC Control" implementation note in PCIe r4.0, sec
6.1.10, recommends the operating system always link DPC control to the
control of AER, as the two functionalities are strongly connected.

To avoid conflicts over whether platform firmware or the OS controls DPC,
enable DPC only if AER is enabled in the OS, and the device's error
handling does not have firmware-first AER handling.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>

PCI: Add SPDX GPL-2.0 when no license was specified

b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to
files with no license") added SPDX GPL-2.0 to several PCI files that
previously contained no license information.

Add SPDX GPL-2.0 to all other PCI files that did not contain any license
information and hence were under the default GPL version 2 license of the
kernel.

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

PCI/ASPM: Add support for L1 substates

Add support for ASPM L1 substates. For details about L1 substates, see the
PCIe r3.1 spec, which includes the ECN below in secs 5.5 and 7.33.

Add macros for the 4 new L1 substates, and add a new ASPM "POWER_SUPERSAVE"
policy that can be used to enable L1 substates on a system if desired. The
new policy is in a sense, a superset of the existing POWERSAVE policy. The
4 policies are now:

DEFAULT: Reads and uses whatever ASPM states BIOS enabled
PERFORMANCE: Everything except L0 disabled.
POWERSAVE: L0s and L1 enabled (but not L1 substates)
POWER_SUPERSAVE: L0s + L1 + L1 substates also enabled

[bhelgaas: add PCIe r3.1 spec reference]
Link: https://pcisig.com/sites/default/files/specification_documents/ECN_L1_PM_Substates_with_CLKREQ_31_May_2013_Rev10a.pdf
Signed-off-by: Rajat Jain <rajatja@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Add Precision Time Measurement (PTM) support

Add Precision Time Measurement (PTM) support (see PCIe r3.1, sec 6.22).

Enable PTM on PTM Root devices and switch ports. This does not enable PTM
on endpoints.

There currently are no PTM-capable devices on the market, but it is
expected to be supported by the Intel Apollo Lake platform.

[bhelgaas: complete rework]
Signed-off-by: Jonathan Yong <jonathan.yong@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Remove DPC tristate module option

Change the Downstream Port Containment config type from tristate to bool.

The driver doesn't automatically load based on any rules, so it needs to be
built-in in order to bind to devices it needs to drive.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Add Downstream Port Containment driver

Add driver for the PCI Express Downstream Port Containment extended
capability. DPC is an optional capability to contain uncorrectable errors
below a port.

For more information on DPC, please see PCI Express Base Specification
Revision 4, section 7.31, or view the PCI-SIG DPC ECN here:

https://pcisig.com/sites/default/files/specification_documents/ECN_DPC_2012-02-09_finalized.pdf

When a DPC event is triggered, the hardware disables downstream links, so
the DPC driver schedules removal for all devices below this port. This may
happen concurrently with a PCIe hotplug driver if enabled. When all
downstream devices are removed and the link state transitions to disabled,
the DPC driver clears the DPC status and interrupt bits so the link may
retrain for a newly connected device.

[bhelgaas: clear (not set) DPC_CTL bits on remove, whitespace cleanup]
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>

PCI: Cleanup pci/pcie/Kconfig whitespace

Clean up style issues in drivers/pci/pcie/Kconfig, in particular all
indentation is now done using tabs, not spaces, and the definition of
PCIEASPM_DEBUG is now separated from the definition of PCIEASPM with a
newline.

Signed-off-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

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: pciehp: Convert pciehp to be builtin only, not modular

Convert pciehp to be builtin only, with no module option.

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

PCI: Rename "PCI Express support" kconfig title

The previous option title "PCI Express support" is confusing. The name
seems to imply this option is required to get PCIe support, which is not
true.

Fix it to "PCI Express Port Bus support" which is more accurate.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: Remove unnecessary dependencies between PME and ACPI

PCIe PME doesn't depend on ACPI, so remove the #includes and
Kconfig dependency.

Based-on-patch-by: Andrew Murray <Andrew.Murray@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI: remove depends on CONFIG_EXPERIMENTAL

The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

PCI: pcie: Add support for setting default ASPM policy

Distributions may wish to provide different defaults for PCIE ASPM
depending on their target audience. Provide a configuration option for
choosing the default policy.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: kconfig: English typo in pci/pcie/Kconfig

Just fix this help text.

Signed-off-by: P. Christeas <xrg@linux.gr>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT

The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.

This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel. A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).

Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PCI: Default PCIe ASPM control to on and require !EMBEDDED to disable

The CONFIG_PCIEASPM option is confusing and potentially dangerous. ASPM is
a hardware mediated feature rather than one under direct OS control, and
even if the config option is disabled the system firmware may have turned
on ASPM on various bits of hardware. This can cause problems later -
various hardware that claims to support ASPM does a poor job of it and may
hang or cause other difficulties. The kernel is able to recognise this in
many cases and disable the ASPM functionality, but only if CONFIG_PCIEASPM
is enabled.

Given that in its default configuration this option will either leave the
hardware as it was originally or disable hardware functionality that may
cause problems, it should by default y. The only reason to disable it
ought to be to reduce code size, so make it dependent on CONFIG_EMBEDDED.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: lrodriguez@atheros.com
Cc: maximlevitsky@gmail.com
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI PM: PCIe PME root port service driver

PCIe native PME detection mechanism is based on interrupts generated
by root ports or event collectors every time a PCIe device sends a
PME message upstream.

Once a PME message has been sent by an endpoint device and received
by its root port (or event collector in the case of root complex
integrated endpoints), the Requester ID from the message header is
registered in the root port's Root Status register. At the same
time, the PME Status bit of the Root Status register is set to
indicate that there's a PME to handle. If PCIe PME interrupt is
enabled for the root port, it generates an interrupt once the PME
Status has been set. After receiving the interrupt, the kernel can
identify the PCIe device that generated the PME using the Requester
ID from the root port's Root Status register. [For details, see PCI
Express Base Specification, Rev. 2.0.]

Implement a driver for the PCIe PME root port service working in
accordance with the above description.

Based on a patch from Shaohua Li <shaohua.li@intel.com>.

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

PCI Express ASPM support should default to 'No'

Running 'make oldconfig' I just noticed that PCIEASPM defaults to
'y' in Kconfig even though the feature is both experimental and the
help text recommends that if you are unsure you say 'n'.
It seems to me that this really should default to 'n', not 'y' at the
moment.
The following patch makes that change. Please consider applying.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: add PCI Express ASPM support

PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.

This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.

In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.

Note: some devices might not work well with aspm, either because chipset
issue or device issue. The patch provide API (pci_disable_link_state),
driver can disable ASPM for specific device.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Revert "PCI: PCIE ASPM support"

This reverts commit 6c723d5bd89f03fc3ef627d50f89ade054d2ee3b.

It caused build errors on non-x86 platforms, config file confusion, and
even some boot errors on some x86-64 boxes. All around, not quite ready
for prime-time :(

Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI: PCIE ASPM support

PCI Express ASPM defines a protocol for PCI Express components in the D0
state to reduce Link power by placing their Links into a low power state
and instructing the other end of the Link to do likewise. This
capability allows hardware-autonomous, dynamic Link power reduction
beyond what is achievable by software-only controlled power management.
However, The device should be configured by software appropriately.
Enabling ASPM will save power, but will introduce device latency.

This patch adds ASPM support in Linux. It introduces a global policy for
ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control
it. The interface can be used as a boot option too. Currently we have
below setting:
-default, BIOS default setting
-powersave, highest power saving mode, enable all available ASPM
state
and clock power management
-performance, highest performance, disable ASPM and clock power
management
By default, the 'default' policy is used currently.

In my test, power difference between powersave mode and performance mode
is about 1.3w in a system with 3 PCIE links.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

pciehp: remove CONFIG_HOTPLUG_PCI_PCIE_POLL_EVENT_MODE

Remove unnecessary CONFIG_HOTPLUG_PCI_PCIE_EVENT_MODE.

The CONFIG_HOTPLUG_PCI_PCIE_POLL_EVENT_MODE option is not needed
because polling mechanism can be enabled through 'pciehp_poll_mode'
module option.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PCI-Express AER implemetation: AER core and aerdriver

Patch 3 implements the core part of PCI-Express AER and aerdrv
port service driver.

When a root port service device is probed, the aerdrv will call
request_irq to register irq handler for AER error interrupt.

When a device sends an PCI-Express error message to the root port,
the root port will trigger an interrupt, by either MSI or IO-APIC,
then kernel would run the irq handler. The handler collects root
error status register and schedules a work. The work will call
the core part to process the error based on its type
(Correctable/non-fatal/fatal).

As for Correctable errors, the patch chooses to just clear the correctable
error status register of the device.

As for the non-fatal error, the patch follows generic PCI error handler
rules to call the error callback functions of the endpoint's driver. If
the device is a bridge, the patch chooses to broadcast the error to
downstream devices.

As for the fatal error, the patch resets the pci-express link and
follows generic PCI error handler rules to call the error callback
functions of the endpoint's driver. If the device is a bridge, the patch
chooses to broadcast the error to downstream devices.

Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!