block: make block_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the block_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240305-class_cleanup-block-v1-1-130bb27b9c72@marliere.net
Signed-off-by: Jens Axboe <axboe@kernel.dk>

driver core: class: make class_register() take a const *

Now that the class code is cleaned up to not modify the class pointer
registered with it, change class_register() to take a const * to allow
the structure to be placed into read-only memory.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023040248-customary-release-4aec@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: make sysfs_dev_char_kobj static

Nothing outside of drivers/base/core.c uses sysfs_dev_char_kobj, so
make it static and document what it is used for so we remember it the
next time we touch it 15 years from now.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-7-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: clean up the logic to determine which /sys/dev/ directory to use

When a dev_t is set in a struct device, an symlink in /sys/dev/ is
created for it either under /sys/dev/block/ or /sys/dev/char/ depending
on the device type.

The logic to determine this would trigger off of the class of the
object, and the kobj_type set in that location. But it turns out that
this deep nesting isn't needed at all, as it's either a choice of block
or "everything else" which is a char device. So make the logic a lot
more simple and obvious, and remove the incorrect comments in the code
that tried to document something that was not happening at all (it is
impossible to set class->dev_kobj to NULL as the class core prevented
that from happening.

This removes the only place that class->dev_kobj was being used, so
after this, it can be removed entirely.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: core: move to use class_to_subsys()

There are a number of places in core.c that need access to the private
subsystem structure of struct class, so move them to use
class_to_subsys() instead of accessing it directly.

This requires exporting class_to_subsys() out of class.c, but keeping it
local to the driver core.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230331093318.82288-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: move sysfs_dev_char_kobj out of class.h

The structure sysfs_dev_char_kobj is local only to the driver core code,
so move it out of the global class.h file and into the internal base.h
file as no one else should be touching this symbol.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230327160319.513974-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: bus: move documentation for lock_key to proper location.

In commit 37e98d9bedb5 ("driver core: bus: move lock_class_key into
dynamic structure"), the lock_key variable moved out of struct bus_type
and into struct subsys_private, yet the documentation for it did not
move. Fix that up and place the documentation comment in the correct
location.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Fixes: 37e98d9bedb5 ("driver core: bus: move lock_class_key into dynamic structure")
Link: https://lore.kernel.org/r/20230324090814.386654-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: base.h: remove extern from function prototypes

The kernel coding style does not require 'extern' in function prototypes
in .h files, so remove them from drivers/base/base.h as they are not
needed.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230324122711.2664537-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: bus: constantify bus_register()

bus_register() is now safe to take a constant * to bus_type, so make
that change and mark the subsys_private bus_type * constant as well.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-24-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: bus: move dev_root out of struct bus_type

Now that all accesses of dev_root is through the bus_get_dev_root()
call, move the pointer out of struct bus_type and into the private
dynamic structure, subsys_private.

With this change, there is no modifiable portions of struct bus_type so
it can be marked as a constant structure and moved to read-only memory.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230313182918.1312597-22-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Make state_synced device attribute writeable

If the file is written to and sync_state() hasn't been called for the
device yet, then call sync_state() for the device independent of the
state of its consumers.

This is useful for supplier devices that have one or more consumers that
don't have a driver but the consumers are in a state that don't use the
resources supplied by the supplier device.

This gives finer grained control than using the
fw_devlink.sync_state=timeout kernel commandline parameter.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20230304005355.746421-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Add fw_devlink.sync_state command line param

When all devices that could probe have finished probing (based on
deferred_probe_timeout configuration or late_initcall() when
!CONFIG_MODULES), this parameter controls what to do with devices that
haven't yet received their sync_state() calls.

fw_devlink.sync_state=strict is the default and the driver core will
continue waiting on all consumers of a device to probe successfully
before sync_state() is called for the device. This is the default
behavior since calling sync_state() on a device when all its consumers
haven't probed could make some systems unusable/unstable. When this
option is selected, we also print the list of devices that haven't had
sync_state() called on them by the time all devices the could probe have
finished probing.

fw_devlink.sync_state=timeout will cause the driver core to give up
waiting on consumers and call sync_state() on any devices that haven't
yet received their sync_state() calls. This option is provided for
systems that won't become unusable/unstable as they might be able to
save power (depends on state of hardware before kernel starts) if all
devices get their sync_state().

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20230304005355.746421-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "devtmpfs: remove return value of devtmpfs_delete_node()"

This reverts commit 9d3fe6aa6b9517408064c7c3134187e8ec77dbf7 as it is
reported to cause boot regressions.

Link: https://lore.kernel.org/r/Y+rSXg14z1Myd8Px@dev-arch.thelio-3990X
Reported-by: Nathan Chancellor <nathan@kernel.org>
Cc: Longlong Xia <xialonglong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

devtmpfs: remove return value of devtmpfs_delete_node()

The only caller of device_del() does not check the return value. And
there's nothing we can do when cleaning things up on a remove path.
Let's make it a void function.

Signed-off-by: Longlong Xia <xialonglong1@huawei.com>
Link: https://lore.kernel.org/r/20230210095444.4067307-4-xialonglong1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: create bus_is_registered()

A local function to the driver core to determine if a bus really is
registered with the kernel or not. To be used only by the driver core
code, as part of the driver registration path as it's not really "safe"
because the bus could be unregistered instantly after being called.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-17-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: add local subsys_get and subsys_put functions

We need to control the reference count of the subsys private structure
instead of directly manipulating the kset reference count of it, so wrap
that logic up in a subsys_get() and subsys_put() function to make it more
obvious as to what is happening.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230208111330.439504-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: bus: move lock_class_key into dynamic structure

Move the lock_class_key structure out of struct bus_type and into the
dynamic structure we create already for all bus_types registered with
the kernel. This saves on static space and removes one more writable
field in struct bus_type.

In the future, the same field can be moved out of the struct class logic
because it shares this same private structure.

Most everyone will never notice this change, as lockdep is not enabled
in real systems so no memory or logic changes are happening for them.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230201083349.4038660-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: device_get_devnode() should take a const *

device_get_devnode() should take a constant * to struct device as it
does not modify it in any way, so modify the function definition to do
this and move it out of device.h as it does not need to be exposed to
the whole kernel tree.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Won Chung <wonchung@google.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-8-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: bus: move bus notifier logic into bus.c

The logic to touch the bus notifier was open-coded in numberous places
in the driver core. Clean that up by creating a local bus_notify()
function and have everyone call this function instead, making the
reading of the caller code simpler and easier to maintain over time.

Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230111092331.3946745-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: change to_subsys_private() to use container_of_const()

The macro to_subsys_private() needs to switch to using
container_of_const() as it turned out to being incorrectly casting a
const pointer to a non-const one. Make this change and fix up the one
offending user to be correctly handling a const pointer properly.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230111093327.3955063-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: mark driver_allows_async_probing static

driver_allows_async_probing is only used in drivers/base/dd.c, so mark
it static and remove the declaration in drivers/base/base.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221030092255.872280-1-hch@lst.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: remove make_class_name declaration

make_class_name has been removed since
commit 39aba963d937 ("driver core: remove CONFIG_SYSFS_DEPRECATED_V2
but keep it for block devices"), so remove it.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20220909063337.1146151-1-cuigaosheng1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Add wait_for_init_devices_probe helper function

Some devices might need to be probed and bound successfully before the
kernel boot sequence can finish and move on to init/userspace. For
example, a network interface might need to be bound to be able to mount
a NFS rootfs.

With fw_devlink=on by default, some of these devices might be blocked
from probing because they are waiting on a optional supplier that
doesn't have a driver. While fw_devlink will eventually identify such
devices and unblock the probing automatically, it might be too late by
the time it unblocks the probing of devices. For example, the IP4
autoconfig might timeout before fw_devlink unblocks probing of the
network interface.

This function is available to temporarily try and probe all devices that
have a driver even if some of their suppliers haven't been added or
don't have drivers.

The drivers can then decide which of the suppliers are optional vs
mandatory and probe the device if possible. By the time this function
returns, all such "best effort" probes are guaranteed to be completed.
If a device successfully probes in this mode, we delete all fw_devlink
discovered dependencies of that device where the supplier hasn't yet
probed successfully because they have to be optional dependencies.

This also means that some devices that aren't needed for init and could
have waited for their optional supplier to probe (when the supplier's
module is loaded later on) would end up probing prematurely with limited
functionality. So call this function only when boot would fail without
it.

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220601070707.3946847-5-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Extend deferred probe timeout on driver registration

The deferred probe timer that's used for this currently starts at
late_initcall and runs for driver_deferred_probe_timeout seconds. The
assumption being that all available drivers would be loaded and
registered before the timer expires. This means, the
driver_deferred_probe_timeout has to be pretty large for it to cover the
worst case. But if we set the default value for it to cover the worst
case, it would significantly slow down the average case. For this
reason, the default value is set to 0.

Also, with CONFIG_MODULES=y and the current default values of
driver_deferred_probe_timeout=0 and fw_devlink=on, devices with missing
drivers will cause their consumer devices to always defer their probes.
This is because device links created by fw_devlink defer the probe even
before the consumer driver's probe() is called.

Instead of a fixed timeout, if we extend an unexpired deferred probe
timer on every successful driver registration, with the expectation more
modules would be loaded in the near future, then the default value of
driver_deferred_probe_timeout only needs to be as long as the worst case
time difference between two consecutive module loads.

So let's implement that and set the default value to 10 seconds when
CONFIG_MODULES=y.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: linux-gpio@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: iommu@lists.linux-foundation.org
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220429220933.1350374-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

software nodes: Split software_node_notify()

Split software_node_notify_remove) out of software_node_notify()
and make device_platform_notify() call the latter on device addition
and the former on device removal.

While at it, put the headers of the above functions into base.h,
because they don't need to be present in a global header file.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

driver core: Export device_driver_attach()

This is intended as a replacement API for device_bind_driver(). It has at
least the following benefits:

- Internal locking. Few of the users of device_bind_driver() follow the
locking rules

- Calls device driver probe() internally. Notably this means that devm
support for probe works correctly as probe() error will call
devres_release_all()

- struct device_driver -> dev_groups is supported

- Simplified calling convention, no need to manually call probe().

The general usage is for situations that already know what driver to bind
and need to ensure the bind is synchronized with other logic. Call
device_driver_attach() after device_add().

If probe() returns a failure then this will be preserved up through to the
error return of device_driver_attach().

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20210617142218.1877096-6-hch@lst.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

driver core: Improve fw_devlink & deferred_probe_timeout interaction

deferred_probe_timeout kernel commandline parameter allows probing of
consumer devices if the supplier devices don't have any drivers.

fw_devlink=on will indefintely block probe() calls on a device if all
its suppliers haven't probed successfully. This completely skips calls
to driver_deferred_probe_check_state() since that's only called when a
.probe() function calls framework APIs. So fw_devlink=on breaks
deferred_probe_timeout.

deferred_probe_timeout in its current state also ignores a lot of
information that's now available to the kernel. It assumes all suppliers
that haven't probed when the timer expires (or when initcalls are done
on a static kernel) will never probe and fails any calls to acquire
resources from these unprobed suppliers.

However, this assumption by deferred_probe_timeout isn't true under many
conditions. For example:
- If the consumer happens to be before the supplier in the deferred
probe list.
- If the supplier itself is waiting on its supplier to probe.

This patch fixes both these issues by relaxing device links between
devices only if the supplier doesn't have any driver that could match
with (NOT bound to) the supplier device. This way, we only fail attempts
to acquire resources from suppliers that truly don't have any driver vs
suppliers that just happen to not have probed yet.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210402040342.2944858-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Update device link status properly for device_bind_driver()

Device link status was not getting updated correctly when
device_bind_driver() is called on a device. This causes a warning[1].
Fix this by updating device links that can be updated and dropping
device links that can't be updated to a sensible state.

[1] - https://lore.kernel.org/lkml/56f7d032-ba5a-a8c7-23de-2969d98c527e@nvidia.com/

Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210302211133.2244281-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: auxiliary bus: Fix calling stage for auxiliary bus init

When the auxiliary device code is built into the kernel, it can be executed
before the auxiliary bus is registered. This causes bus->p to be not
allocated and triggers a NULL pointer dereference when the auxiliary bus
device gets added with bus_add_device(). Call the auxiliary_bus_init()
under driver_init() so the bus is initialized before devices.

Below is the kernel splat for the bug:
[ 1.948215] BUG: kernel NULL pointer dereference, address: 0000000000000060
[ 1.950670] #PF: supervisor read access in kernel mode
[ 1.950670] #PF: error_code(0x0000) - not-present page
[ 1.950670] PGD 0
[ 1.950670] Oops: 0000 1 SMP NOPTI
[ 1.950670] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-intel-nextsvmtest+ #2205
[ 1.950670] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1.950670] RIP: 0010:bus_add_device+0x64/0x140
[ 1.950670] Code: 00 49 8b 75 20 48 89 df e8 59 a1 ff ff 41 89 c4 85 c0 75 7b 48 8b 53 50 48 85 d2 75 03 48 8b 13 49 8b 85 a0 00 00 00 48 89 de <48> 8
78 60 48 83 c7 18 e8 ef d9 a9 ff 41 89 c4 85 c0 75 45 48 8b
[ 1.950670] RSP: 0000:ff46032ac001baf8 EFLAGS: 00010246
[ 1.950670] RAX: 0000000000000000 RBX: ff4597f7414aa680 RCX: 0000000000000000
[ 1.950670] RDX: ff4597f74142bbc0 RSI: ff4597f7414aa680 RDI: ff4597f7414aa680
[ 1.950670] RBP: ff46032ac001bb10 R08: 0000000000000044 R09: 0000000000000228
[ 1.950670] R10: ff4597f741141b30 R11: ff4597f740182a90 R12: 0000000000000000
[ 1.950670] R13: ffffffffa5e936c0 R14: 0000000000000000 R15: 0000000000000000
[ 1.950670] FS: 0000000000000000(0000) GS:ff4597f7bba00000(0000) knlGS:0000000000000000
[ 1.950670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1.950670] CR2: 0000000000000060 CR3: 000000002140c001 CR4: 0000000000f71ef0
[ 1.950670] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1.950670] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
[ 1.950670] PKRU: 55555554
[ 1.950670] Call Trace:
[ 1.950670] device_add+0x3ee/0x850
[ 1.950670] __auxiliary_device_add+0x47/0x60
[ 1.950670] idxd_pci_probe+0xf77/0x1180
[ 1.950670] local_pci_probe+0x4a/0x90
[ 1.950670] pci_device_probe+0xff/0x1b0
[ 1.950670] really_probe+0x1cf/0x440
[ 1.950670] ? rdinit_setup+0x31/0x31
[ 1.950670] driver_probe_device+0xe8/0x150
[ 1.950670] device_driver_attach+0x58/0x60
[ 1.950670] __driver_attach+0x8f/0x150
[ 1.950670] ? device_driver_attach+0x60/0x60
[ 1.950670] ? device_driver_attach+0x60/0x60
[ 1.950670] bus_for_each_dev+0x79/0xc0
[ 1.950670] ? kmem_cache_alloc_trace+0x323/0x430
[ 1.950670] driver_attach+0x1e/0x20
[ 1.950670] bus_add_driver+0x154/0x1f0
[ 1.950670] driver_register+0x70/0xc0
[ 1.950670] __pci_register_driver+0x54/0x60
[ 1.950670] idxd_init_module+0xe2/0xfc
[ 1.950670] ? idma64_platform_driver_init+0x19/0x19
[ 1.950670] do_one_initcall+0x4a/0x1e0
[ 1.950670] kernel_init_freeable+0x1fc/0x25c
[ 1.950670] ? rest_init+0xba/0xba
[ 1.950670] kernel_init+0xe/0x116
[ 1.950670] ret_from_fork+0x1f/0x30
[ 1.950670] Modules linked in:
[ 1.950670] CR2: 0000000000000060
[ 1.950670] --[ end trace cd7d1b226d3ca901 ]--

Fixes: 7de3697e9cbd ("Add auxiliary bus support")
Reported-by: Jacob Pan <jacob.jun.pan@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Dave Ertman <david.m.ertman@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20210210201611.1611074-1-dave.jiang@intel.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: make driver_probe_device() static

It's only used inside drivers/base/dd.c

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Link: https://lore.kernel.org/r/20201123111938.18968-1-jwi@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "driver core: fw_devlink: Add support for batching fwnode parsing"

This reverts commit 716a7a25969003d82ab738179c3f1068a120ed11.

The fw_devlink_pause/resume() APIs added by the commit being reverted
were a first cut attempt at optimizing boot time. But these APIs don't
fully solve the problem and are very fragile (can only be used for the
top level devices being added). This series replaces them with a much
better optimization that works for all device additions and also has the
benefit of reducing the complexity of the firmware (DT, EFI) specific
code and abstracting out common code to driver core.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-7-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "driver core: Don't do deferred probe in parallel with kernel_init thread"

This reverts commit cec72f3efc6272420c2c2c699607f03d09b93e41.

Commit cec72f3efc62 ("driver core: Don't do deferred probe in parallel
with kernel_init thread") was fixing a commit 716a7a259690 ("driver
core: fw_devlink: Add support for batching fwnode parsing"). Since the
commit being fixed itself is going to be reverted, the fix can also be
reverted.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: add deferring probe reason to devices_deferred property

/sys/kernel/debug/devices_deferred property contains list of deferred devices.
This list does not contain reason why the driver deferred probe, the patch
improves it.
The natural place to set the reason is dev_err_probe function introduced
recently, ie. if dev_err_probe will be called with -EPROBE_DEFER instead of
printk the message will be attached to a deferred device and printed when user
reads devices_deferred property.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20200713144324.23654-3-a.hajda@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Don't do deferred probe in parallel with kernel_init thread

The current deferred probe implementation can mess up suspend/resume
ordering if deferred probe thread is kicked off in parallel with the
main initcall thread (kernel_init thread) [1].

For example:

Say device-B is a consumer of device-A.

Initcall thread Deferred probe thread
=============== =====================
1. device-A is added.
2. device-B is added.
3. dpm_list is now [device-A, device-B].
4. driver-A defers probe of device-A.
5. device-A is moved to
end of dpm_list
6. dpm_list is now
[device-B, device-A]
7. driver-B is registereed and probes device-B.
8. dpm_list stays as [device-B, device-A].

The reverse order of dpm_list is used for suspend. So in this case
device-A would incorrectly get suspended before device-B.

Commit 716a7a259690 ("driver core: fw_devlink: Add support for batching
fwnode parsing") kicked off the deferred probe thread early during boot
to run in parallel with the initcall thread and caused suspend/resume
regressions. This patch removes the parallel run of the deferred probe
thread to avoid the suspend/resume regressions.

[1] - https://lore.kernel.org/lkml/CAGETcx8W96KAw-d_siTX4qHB_-7ddk0miYRDQeHE6E0_8qx-6Q@mail.gmail.com/

Fixes: 716a7a259690 ("driver core: fw_devlink: Add support for batching fwnode parsing")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200701194259.3337652-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: fw_devlink: Add support for batching fwnode parsing

The amount of time spent parsing fwnodes of devices can become really
high if the devices are added in an non-ideal order. Worst case can be
O(N^2) when N devices are added. But this can be optimized to O(N) by
adding all the devices and then parsing all their fwnodes in one batch.

This commit adds fw_devlink_pause() and fw_devlink_resume() to allow
doing this.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200515053500.215929-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

device.h: move devtmpfs prototypes out of the file

The devtmpfs functions do not need to be in device.h as only the driver
core uses them, so move them to the private .h file for the driver core.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20191209193303.1694546-3-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base: base.h: add proper copyright and header info

base.h didn't have any copyright information in it, so update it with
the correct information.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20191209193303.1694546-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver/core: Convert to use built-in RCU list checking

This commit applies the consolidated hlist_for_each_entry_rcu() support
for lockdep conditions.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>

driver core: Probe devices asynchronously instead of the driver

Probe devices asynchronously instead of the driver. This results in us
seeing the same behavior if the device is registered before the driver or
after. This way we can avoid serializing the initialization should the
driver not be loaded until after the devices have already been added.

The motivation behind this is that if we have a set of devices that
take a significant amount of time to load we can greatly reduce the time to
load by processing them in parallel instead of one at a time. In addition,
each device can exist on a different node so placing a single thread on one
CPU to initialize all of the devices for a given driver can result in poor
performance on a system with multiple nodes.

This approach can reduce the time needed to scan SCSI LUNs significantly.
The only way to realize that speedup is by enabling more concurrency which
is what is achieved with this patch.

To achieve this it was necessary to add a new member "async_driver" to the
device_private structure to store the driver pointer while we wait on the
deferred probe call.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

device core: Consolidate locking and unlocking of parent and device

Try to consolidate all of the locking and unlocking of both the parent and
device when attaching or removing a driver from a given device.

To do that I first consolidated the lock pattern into two functions
__device_driver_lock and __device_driver_unlock. After doing that I then
created functions specific to attaching and detaching the driver while
acquiring these locks. By doing this I was able to reduce the number of
spots where we touch need_parent_lock from 12 down to 4.

This patch should produce no functional changes, it is meant to be a code
clean-up/consolidation only.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Establish order of operations for device_add and device_del via bitflag

Add an additional bit flag to the device_private struct named "dead".

This additional flag provides a guarantee that when a device_del is
executed on a given interface an async worker will not attempt to attach
the driver following the earlier device_del call. Previously this
guarantee was not present and could result in the device_del call
attempting to remove a driver from an interface only to have the async
worker attempt to probe the driver later when it finally completes the
asynchronous probe call.

One additional change added was that I pulled the check for dev->driver
out of the __device_attach_driver call and instead placed it in the
__device_attach_async_helper call. This was motivated by the fact that the
only other caller of this, __device_attach, had already taken the
device_lock() and checked for dev->driver. Instead of testing for this
twice in this path it makes more sense to just consolidate the dev->dead
and dev->driver checks together into one set of checks.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: move device->knode_class to device_private

As the description of struct device_private says, it stores data which
is private to driver core. And it already has similar fields like:
knode_parent, knode_driver, knode_driver and knode_bus. This look it is
more proper to put knode_class together with those fields to make it
private to driver core.

This patch move device->knode_class to device_private to make it comply
with code convention.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: remove unnecessary function extern declare

device_private_init is called only in core.c, extern declare is
unnecessary and make it static.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / core: fix deferred probe breaking suspend resume order

When bridge and its endpoint is enumerated the devices are added to the
dpm list. Afterward, the bridge defers probe when IOMMU is not ready.
This causes the bridge to be moved to the end of the dpm list when
deferred probe kicks in. The order of the dpm list for bridge and
endpoint is reversed.

Add reordering code to move the bridge and its children and consumers to
the end of the pm list so the order for suspend and resume is not altered.
The code also move device and its children and consumers to the tail of
device_kset list if it is registered.

Signed-off-by: Toan Le <toanle@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: make device_{add|remove}_groups() public

Many drivers create additional driver-specific device attributes when
binding to the device. To avoid them calling SYSFS API directly, let's
export these helpers.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "driver core: Add deferred_probe attribute to devices in sysfs"

This reverts commit 6751667a29d6fd64afb9ce30567ad616b68ed789.

Rob Herring objected to it, and a replacement for it will be added using
debugfs in the future.

Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Reported-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Add deferred_probe attribute to devices in sysfs

It is sometimes useful to know that a device is on the deferred probe
list rather than, say, not having a driver available. Expose this
information to user-space.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Functional dependencies tracking support

Currently, there is a problem with taking functional dependencies
between devices into account.

What I mean by a "functional dependency" is when the driver of device
B needs device A to be functional and (generally) its driver to be
present in order to work properly. This has certain consequences
for power management (suspend/resume and runtime PM ordering) and
shutdown ordering of these devices. In general, it also implies that
the driver of A needs to be working for B to be probed successfully
and it cannot be unbound from the device before the B's driver.

Support for representing those functional dependencies between
devices is added here to allow the driver core to track them and act
on them in certain cases where applicable.

The argument for doing that in the driver core is that there are
quite a few distinct use cases involving device dependencies, they
are relatively hard to get right in a driver (if one wants to
address all of them properly) and it only gets worse if multiplied
by the number of drivers potentially needing to do it. Morever, at
least one case (asynchronous system suspend/resume) cannot be handled
in a single driver at all, because it requires the driver of A to
wait for B to suspend (during system suspend) and the driver of B to
wait for A to resume (during system resume).

For this reason, represent dependencies between devices as "links",
with the help of struct device_link objects each containing pointers
to the "linked" devices, a list node for each of them, status
information, flags, and an RCU head for synchronization.

Also add two new list heads, representing the lists of links to the
devices that depend on the given one (consumers) and to the devices
depended on by it (suppliers), and a "driver presence status" field
(needed for figuring out initial states of device links) to struct
device.

The entire data structure consisting of all of the lists of link
objects for all devices is protected by a mutex (for link object
addition/removal and for list walks during device driver probing
and removal) and by SRCU (for list walking in other case that will
be introduced by subsequent change sets). If CONFIG_SRCU is not
selected, however, an rwsem is used for protecting the entire data
structure.

In addition, each link object has an internal status field whose
value reflects whether or not drivers are bound to the devices
pointed to by the link or probing/removal of their drivers is in
progress etc. That field is only modified under the device links
mutex, but it may be read outside of it in some cases (introduced by
subsequent change sets), so modifications of it are annotated with
WRITE_ONCE().

New links are added by calling device_link_add() which takes three
arguments: pointers to the devices in question and flags. In
particular, if DL_FLAG_STATELESS is set in the flags, the link status
is not to be taken into account for this link and the driver core
will not manage it. In turn, if DL_FLAG_AUTOREMOVE is set in the
flags, the driver core will remove the link automatically when the
consumer device driver unbinds from it.

One of the actions carried out by device_link_add() is to reorder
the lists used for device shutdown and system suspend/resume to
put the consumer device along with all of its children and all of
its consumers (and so on, recursively) to the ends of those lists
in order to ensure the right ordering between all of the supplier
and consumer devices.

For this reason, it is not possible to create a link between two
devices if the would-be supplier device already depends on the
would-be consumer device as either a direct descendant of it or a
consumer of one of its direct descendants or one of its consumers
and so on.

There are two types of link objects, persistent and non-persistent.
The persistent ones stay around until one of the target devices is
deleted, while the non-persistent ones are removed automatically when
the consumer driver unbinds from its device (ie. they are assumed to
be valid only as long as the consumer device has a driver bound to
it). Persistent links are created by default and non-persistent
links are created when the DL_FLAG_AUTOREMOVE flag is passed
to device_link_add().

Both persistent and non-persistent device links can be deleted
with an explicit call to device_link_del().

Links created without the DL_FLAG_STATELESS flag set are managed
by the driver core using a simple state machine. There are 5 states
each link can be in: DORMANT (unused), AVAILABLE (the supplier driver
is present and functional), CONSUMER_PROBE (the consumer driver is
probing), ACTIVE (both supplier and consumer drivers are present and
functional), and SUPPLIER_UNBIND (the supplier driver is unbinding).
The driver core updates the link state automatically depending on
what happens to the linked devices and for each link state specific
actions are taken in addition to that.

For example, if the supplier driver unbinds from its device, the
driver core will also unbind the drivers of all of its consumers
automatically under the assumption that they cannot function
properly without the supplier. Analogously, the driver core will
only allow the consumer driver to bind to its device if the
supplier driver is present and functional (ie. the link is in
the AVAILABLE state). If that's not the case, it will rely on
the existing deferred probing mechanism to wait for the supplier
driver to become available.

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

PM / sleep: prohibit devices probing during suspend/hibernation

It is unsafe [1] if probing of devices will happen during suspend or
hibernation and system behavior will be unpredictable in this case.
So, let's prohibit device's probing in dpm_prepare() and defer their
probing instead. The normal behavior will be restored in
dpm_complete().

This patch introduces new DD core APIs:
device_block_probing()
It will disable probing of devices and defer their probes instead.
device_unblock_probing()
It will restore normal behavior and trigger re-probing of deferred
devices.

[1] https://lkml.org/lkml/2015/9/11/554

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

driver core: correct device's shutdown order

Now device's shutdown sequence is performed in reverse order of their
registration in devices_kset list and this sequence corresponds to the
reverse device's creation order. So, devices_kset data tracks
"parent<-child" device's dependencies only.

Unfortunately, that's not enough and causes problems in case of
implementing board's specific shutdown procedures. For example [1]:
"DRA7XX_evm uses PCF8575 and one of the PCF output lines feeds to
MMC/SD and this line should be driven high in order for the MMC/SD to
be detected. This line is modelled as regulator and the hsmmc driver
takes care of enabling and disabling it. In the case of 'reboot',
during shutdown path as part of it's cleanup process the hsmmc driver
disables this regulator. This makes MMC boot not functional."

To handle this issue the .shutdown() callback could be implemented
for PCF8575 device where corresponding GPIO pins will be configured to
states, required for correct warm/cold reset. This can be achieved
only when all .shutdown() callbacks have been called already for all
PCF8575's consumers. But devices_kset is not filled correctly now:

devices_kset: Device61 4e000000.dmm
devices_kset: Device62 48070000.i2c
devices_kset: Device63 48072000.i2c
devices_kset: Device64 48060000.i2c
devices_kset: Device65 4809c000.mmc
...
devices_kset: Device102 fixedregulator-sd
...
devices_kset: Device181 0-0020 // PCF8575
devices_kset: Device182 gpiochip496
devices_kset: Device183 0-0021 // PCF8575
devices_kset: Device184 gpiochip480

As can be seen from above .shutdown() callback for PCF8575 will be called
before its consumers, which, in turn means, that any changes of PCF8575
GPIO's pins will be or unsafe or overwritten later by GPIO's consumers.
The problem can be solved if devices_kset list will be filled not only
according device creation order, but also according device's probing
order to track "supplier<-consumer" dependencies also.

Hence, as a fix, lets add devices_kset_move_last(),
devices_kset_move_before(), devices_kset_move_after() and call them
from device_move() and also add call of devices_kset_move_last() in
really_probe(). After this change all entries in devices_kset will
be sorted according to device's creation ("parent<-child") and
probing ("supplier<-consumer") order.

devices_kset after:
devices_kset: Device121 48070000.i2c
devices_kset: Device122 i2c-0
...
devices_kset: Device147 regulator.24
devices_kset: Device148 0-0020
devices_kset: Device149 gpiochip496
devices_kset: Device150 0-0021
devices_kset: Device151 gpiochip480
devices_kset: Device152 0-0019
...
devices_kset: Device372 fixedregulator-sd
devices_kset: Device373 regulator.29
devices_kset: Device374 4809c000.mmc
devices_kset: Device375 mmc0

[1] http://www.spinics.net/lists/linux-mmc/msg29825.html

Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: fix docbook for device_private.device

This field refers to the public device struct, not to classes.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver-core: add asynchronous probing support for drivers

Some devices take a long time when initializing, and not all drivers are
suited to initialize their devices when they are open. For example,
input drivers need to interrogate their devices in order to publish
device's capabilities before userspace will open them. When such drivers
are compiled into kernel they may stall entire kernel initialization.

This change allows drivers request for their probe functions to be
called asynchronously during driver and device registration (manual
binding is still synchronous). Because async_schedule is used to perform
asynchronous calls module loading will still wait for the probing to
complete.

Note that the end goal is to make the probing asynchronous by default,
so annotating drivers with PROBE_PREFER_ASYNCHRONOUS is a temporary
measure that allows us to speed up boot process while we validating and
fixing the rest of the drivers and preparing userspace.

This change is based on earlier patch by "Luis R. Rodriguez"
<mcgrof@suse.com>

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: Move driver_data back to struct device

Having to allocate memory as part of dev_set_drvdata() is a problem
because that memory may never get freed if the device itself is not
created. So move driver_data back to struct device.

This is a partial revert of commit b4028437.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI / hotplug / driver core: Handle containers in a special way

ACPI container devices require special hotplug handling, at least
on some systems, since generally user space needs to carry out
system-specific cleanup before it makes sense to offline devices in
the container. However, the current ACPI hotplug code for containers
first attempts to offline devices in the container and only then it
notifies user space of the container offline.

Moreover, after commit 202317a573b2 (ACPI / scan: Add acpi_device
objects for all device nodes in the namespace), ACPI device objects
representing containers are present as long as the ACPI namespace
nodes corresponding to them are present, which may be forever, even
if the container devices are physically detached from the system (the
return values of the corresponding _STA methods change in those
cases, but generally the namespace nodes themselves are still there).
Thus it is useful to introduce entities representing containers that
will go away during container hot-unplug.

The goal of this change is to address both the above issues.

The idea is to create a "companion" container system device for each
of the ACPI container device objects during the initial namespace
scan or on a hotplug event making the container present. That system
device will be unregistered on container removal. A new bus type
for container devices is added for this purpose, because device
offline and online operations need to be defined for them. The
online operation is a trivial function that is always successful
and the offline uses a callback pointed to by the container device's
offline member.

For ACPI containers that callback simply walks the list of ACPI
device objects right below the container object (its children) and
checks if all of their physical companion devices are offline. If
that's not the case, it returns -EBUSY and the container system
devivce cannot be put offline. Consequently, to put the container
system device offline, it is necessary to put all of the physical
devices depending on its ACPI companion object offline beforehand.

Container system devices created for ACPI container objects are
initially online. They are created by the container ACPI scan
handler whose hotplug.demand_offline flag is set. That causes
acpi_scan_hot_remove() to check if the companion container system
device is offline before attempting to remove an ACPI container or
any devices below it. If the check fails, a KOBJ_CHANGE uevent is
emitted for the container system device in question and user space
is expected to offline all devices below the container and the
container itself in response to it. Then, user space can finalize
the removal of the container with the help of its ACPI device
object's eject attribute in sysfs.

Tested-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: bus_type: add drv_groups

attribute groups are much more flexible than just a list of attributes,
due to their support for visibility of the attributes, and binary
attributes. Add drv_groups to struct bus_type which should be used
instead of drv_attrs.

drv_attrs will be removed from the structure soon.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: bus_type: add dev_groups

attribute groups are much more flexible than just a list of attributes,
due to their support for visibility of the attributes, and binary
attributes. Add dev_groups to struct bus_type which should be used
instead of dev_attrs.

dev_attrs will be removed from the structure soon.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver/base: implement subsys_virtual_register()

Kay tells me the most appropriate place to expose workqueues to
userland would be /sys/devices/virtual/workqueues/WQ_NAME which is
symlinked to /sys/bus/workqueue/devices/WQ_NAME and that we're lacking
a way to do that outside of driver core as virtual_device_parent()
isn't exported and there's no inteface to conveniently create a
virtual subsystem.

This patch implements subsys_virtual_register() by factoring out
subsys_register() from subsys_system_register() and using it with
virtual_device_parent() as the origin directory. It's identical to
subsys_system_register() other than the origin directory but we aren't
gonna restrict the device names which should be used under it.

This will be used to expose workqueue attributes to userland.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>

driver core: move the deferred probe pointer into the private area

Nothing outside of the driver core needs to get to the deferred probe
pointer, so move it inside the private area of 'struct device' so no one
tries to mess around with it.

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivercore: Add driver probe deferral mechanism

Allow drivers to report at probe time that they cannot get all the resources
required by the device, and should be retried at a later time.

This should completely solve the problem of getting devices
initialized in the right order. Right now this is mostly handled by
mucking about with initcall ordering which is a complete hack, and
doesn't even remotely handle the case where device drivers are in
modules. This approach completely sidesteps the issues by allowing
driver registration to occur in any order, and any driver can request
to be retried after a few more other drivers get probed.

v4: - Integrate Manjunath's addition of a separate workqueue
- Change -EAGAIN to -EPROBE_DEFER for drivers to trigger deferral
- Update comment blocks to reflect how the code really works
v3: - Hold off workqueue scheduling until late_initcall so that the bulk
of driver probes are complete before we start retrying deferred devices.
- Tested with simple use cases. Still needs more testing though.
Using it to get rid of the gpio early_initcall madness, or to replace
the ASoC internal probe deferral code would be ideal.
v2: - added locking so it should no longer be utterly broken in that regard
- remove device from deferred list at device_del time.
- Still completely untested with any real use case, but has been
boot tested.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dilan Lee <dilee@nvidia.com>
Cc: Manjunath GKondaiah <manjunath.gkondaiah@linaro.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

cpu: Do not return errors from cpu_dev_init() which will be ignored

cpu_dev_init() is only called from driver_init(), which does not check
its return value. Therefore make cpu_dev_init() return void.

We must register the CPU subsystem, so panic if this fails.

If sched_create_sysfs_power_savings_entries() fails, the damage is
contained, so ignore this (as before).

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

driver-core: implement 'sysdev' functionality for regular devices and buses

All sysdev classes and sysdev devices will converted to regular devices
and buses to properly hook userspace into the event processing.

There is no interesting difference between a 'sysdev' and 'device' which
would justify to roll an entire own subsystem with different userspace
export semantics. Userspace relies on events and generic sysfs subsystem
infrastructure from sysdev devices, which are currently not properly
available.

Every converted sysdev class will create a regular device with the class
name in /sys/devices/system and all registered devices will becom a children
of theses devices.

For compatibility reasons, the sysdev class-wide attributes are created
at this parent device. (Do not copy that logic for anything new, subsystem-
wide properties belong to the subsystem, not to some fake parent device
created in /sys/devices.)

Every sysdev driver is implemented as a simple subsystem interface now,
and no longer called a driver.

After all sysdev classes are ported to regular driver core entities, the
sysdev implementation will be entirely removed from the kernel.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/base: base.h implicitly depends on <linux/notifier.h>

This file is currently relying on <linux/module.h> sneaking it in
through the implicit include paths from device.h. Once that
is cleaned up, this will happen:

In file included from drivers/base/init.c:12:
drivers/base/base.h:34: error: field ‘bus_notifier’ has incomplete type
make[3]: *** [drivers/base/init.o] Error 1

Fix it up in advance, so the cleanup can continue.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

PM: Remove sysdev suspend, resume and shutdown operations

Since suspend, resume and shutdown operations in struct sysdev_class
and struct sysdev_driver are not used any more, remove them. Also
drop sysdev_suspend(), sysdev_resume() and sysdev_shutdown() used
for executing those operations and modify all of their users
accordingly. This reduces kernel code size quite a bit and reduces
its complexity.

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

driver-core: merge private parts of class and bus

As classes and busses are pretty much the same thing, and we want to
merge them together into a 'subsystem' in the future, let us share the
same private data parts to make that merge easier.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev

Devtmpfs lets the kernel create a tmpfs instance called devtmpfs
very early at kernel initialization, before any driver-core device
is registered. Every device with a major/minor will provide a
device node in devtmpfs.

Devtmpfs can be changed and altered by userspace at any time,
and in any way needed - just like today's udev-mounted tmpfs.
Unmodified udev versions will run just fine on top of it, and will
recognize an already existing kernel-created device node and use it.
The default node permissions are root:root 0600. Proper permissions
and user/group ownership, meaningful symlinks, all other policy still
needs to be applied by userspace.

If a node is created by devtmps, devtmpfs will remove the device node
when the device goes away. If the device node was created by
userspace, or the devtmpfs created node was replaced by userspace, it
will no longer be removed by devtmpfs.

If it is requested to auto-mount it, it makes init=/bin/sh work
without any further userspace support. /dev will be fully populated
and dynamic, and always reflect the current device state of the kernel.
With the commonly used dynamic device numbers, it solves the problem
where static devices nodes may point to the wrong devices.

It is intended to make the initial bootup logic simpler and more robust,
by de-coupling the creation of the inital environment, to reliably run
userspace processes, from a complex userspace bootstrap logic to provide
a working /dev.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Tested-By: Harald Hoyer <harald@redhat.com>
Tested-By: Scott James Remnant <scott@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: move dev_get/set_drvdata to drivers/base/dd.c

No one should directly access the driver_data field, so remove the field
and make it private. We dynamically create the private field now if it
is needed, to handle drivers that call get/set before they are
registered with the driver core.

Also update the copyright notices on these files while we are there.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: add new device to bus's list before probing

This patch (as1271) affects when new devices get linked into their
bus's list of devices. Currently this happens after probing, and it
doesn't happen at all if probing fails. Clearly this is wrong,
because at that point quite a few symbolic links have already been
created in sysfs. We are committed to adding the device, so it should
be linked into the bus's list regardless.

In addition, this needs to happen before the uevent announcing the new
device gets issued. Otherwise user programs might try to access the
device before it has been added to the bus.

To fix both these problems, the patch moves the call to
klist_add_tail() forward from bus_attach_device() to bus_add_device().
Since bus_attach_device() now does nothing but probe for drivers, it
has been renamed to bus_probe_device(). And lastly, the kerneldoc is
updated.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: fix driver_match_device

This patch fixes a bug introduced in commit
49b420a13ff95b449947181190b08367348e3e1b.

If a instance of bus_type doesn't have .match method,
all .probe of drivers in the bus should be called, or else
the .probe have not a chance to be called.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reported-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move knode_bus into private structure

Nothing outside of the driver core should ever touch knode_bus, so
move it out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move knode_driver into private structure

Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move klist_children into private structure

Nothing outside of the driver core should ever touch klist_children, or
knode_parent, so move them out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: create a private portion of struct device

This is to be used to move things out of struct device that no code
outside of the driver core should ever touch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: check bus->match without holding device lock

This patch moves bus->match out from driver_probe_device and
does not hold device lock to check the match between a device
and a driver.

The idea has been verified by the commit 6cd495860901,
which leads to a faster boot. But the commit 6cd495860901 has
the following drawbacks: 1),only does the quick check in
the path of __driver_attach->driver_probe_device, not in other
paths; 2),for a matched device and driver, check the same match
twice. It is a waste of cpu ,especially for some drivers with long
device id table (eg. usb-storage driver).

This patch adds a helper of driver_match_device to check the match
in all paths, and testes the match only once.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PM: Split up sysdev_[suspend|resume] from device_power_[down|up]

Move the sysdev_suspend/resume from the callee to the callers, with
no real change in semantics, so that we can rework the disabling of
interrupts during suspend/hibernation.

This is based on an earlier patch from Linus.

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

Revert "driver core: create a private portion of struct device"

This reverts commit 2831fe6f9cc4e16c103504ee09a47a084297c0f3.

Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.

Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Revert "driver core: move klist_children into private structure"

This reverts commit 11c3b5c3e08f4d855cbef52883c266b9ab9df879.

Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.

Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Revert "driver core: move knode_driver into private structure"

This reverts commit 93e746db183b3bdbbda67900f79b5835f9cb388f.

Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.

Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Revert "driver core: move knode_bus into private structure"

This reverts commit b9daa99ee533578e3f88231e7a16784dcb44ec42.

Turns out that device_initialize shouldn't fail silently.
This series needs to be reworked in order to get into proper
shape.

Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move knode_bus into private structure

Nothing outside of the driver core should ever touch knode_bus, so
move it out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move knode_driver into private structure

Nothing outside of the driver core should ever touch knode_driver, so
move it out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: move klist_children into private structure

Nothing outside of the driver core should ever touch klist_children, or
knode_parent, so move them out of the public eye.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: create a private portion of struct device

This is to be used to move things out of struct device that no code
outside of the driver core should ever touch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver-core: use klist for class device list and implement iterator

Iterating over entries using callback usually isn't too fun especially
when the entry being iterated over can't be manipulated freely. This
patch converts class->p->class_devices to klist and implements class
device iterator so that the users can freely build their own control
structure. The users are also free to call back into class code
without worrying about locking.

class_for_each_device() and class_find_device() are converted to use
the new iterators, so their users don't have to worry about locking
anymore either.

Note: This depends on klist-dont-iterate-over-deleted-entries patch
because class_intf->add/remove_dev() depends on proper synchronization
with device removal.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

class: change internal semaphore to a mutex

Now that the lockdep infrastructure in the class core is in place, we
should be able to properly change the internal class semaphore to be a
mutex.

David wrote the original patch, and Greg fixed it up to apply properly
due to all of the recent changes in this area.

From: Dave Young <hidave.darkstar@gmail.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

class: fix docbook comments for class_private structure

Removes a field that has been deleted, and adds a description fo the
class_dirs field which was previously undocumented.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

class: rename "sem" to "class_sem" in internal class structure

This renames the struct class "sem" field to be "class_sem" to make
things easier when struct bus_type and struct class merge in the future.
It also makes grepping for fields easier as well.

Based on an idea from Kay.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

class: rename "subsys" to "class_subsys" in internal class structure

This renames the struct class "subsys" field to be "class_subsys" to
make things easier when struct bus_type and struct class merge in the
future. It also makes grepping for fields easier as well.

Based on an idea from Kay.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

class: rename "interfaces" to "class_interfaces" in internal class structure

This renames the struct class "interfaces" field to be
"class_interfaces" to make things easier when struct bus_type and struct
class merge in the future. It also makes grepping for fields easier as
well.

Based on an idea from Kay.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

class: rename "devices" to "class_devices" in internal class structure

This renames the struct class "devices" field to be "class_devices" to
make things easier when struct bus_type and struct class merge in the
future. It also makes grepping for fields easier as well.

Based on an idea from Kay.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

class: move driver core specific parts to a private structure

This moves the portions of struct class that are dynamic (kobject and
lock and lists) out of the main structure and into a dynamic, private,
structure.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: remove no longer used "struct class_device"

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: coding style fixes

Fix up a number of coding style issues in the drivers/base/ directory
that have annoyed me over the years. checkpatch.pl is now very happy.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: fix build with SYSFS=n

When SYSFS=n and MODULES=y, build ends with:

linux-2.6.24-rc6-mm1/drivers/base/module.c: In function 'module_add_driver':
linux-2.6.24-rc6-mm1/drivers/base/module.c:49: error: 'module_kset' undeclared (first use in this function)
make[3]: *** [drivers/base/module.o] Error 1

Below is one possible fix.
Build-tested with all 4 config combinations of SYSFS & MODULES.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: use LIST_HEAD instead of call to INIT_LIST_HEAD in __init

LIST_HEAD has been widely used, so switch to this simpler method.

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: move the static kobject out of struct driver

This patch removes the kobject, and a few other driver-core-only fields
out of struct driver and into the driver core only. Now drivers can be
safely create on the stack or statically (like they currently are.)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: move the driver specific module code into the driver core

The module driver specific code should belong in the driver core, not in
the kernel/ directory. So move this code. This is done in preparation
for some struct device_driver rework that should be confined to the
driver core code only.

This also lets us keep from exporting these functions, as no external
code should ever be calling it.

Thanks to Andrew Morton for the !CONFIG_MODULES fix.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: remove fields from struct bus_type

struct bus_type is static everywhere in the kernel. This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure. This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.

Thanks to Kay for the build fixes on this patch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

kset: convert /sys/devices to use kset_create

Dynamically create the kset instead of declaring it statically. We also
rename devices_subsys to devices_kset to catch all users of the
variable.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: remove get_bus()

get_bus() should not be globally visable as it is not used by anything
other than drivers/base/bus.c. This patch removes the visability of it,
and renames it to match all of the other *_get() functions in the
kernel.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: remove put_bus()

put_bus() should not be globally visable as it is not used by anything
other than drivers/base/bus.c. This patch removes the visability of it,
and renames it to match all of the other *_put() functions in the
kernel.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver core: fix devres_release_all() return value

Every file should include the headers containing the prototypes for
it's global functions.

Since the GNU C compiler is now able to detect that the function
prototype of devres_release_all() in the header and the actual function
disagree regarding the return value, this patch also fixes this bug.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

remove "struct subsystem" as it is no longer needed

We need to work on cleaning up the relationship between kobjects, ksets and
ktypes. The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.

Thanks to Kay for fixing the bugs in this patch.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

driver core: don't fail attaching the device if it cannot be bound

Don't fail bus_attach_device() if the device cannot be bound.

If dev->driver has been specified, reset it to NULL if device_bind_driver()
failed and add the device as an unbound device. As a result,
bus_attach_device() now cannot fail, and we can remove some checking from
device_add().

Also remove an unneeded check in bus_rescan_devices_helper().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

devres: device resource management

Implement device resource management, in short, devres. A device
driver can allocate arbirary size of devres data which is associated
with a release function. On driver detach, release function is
invoked on the devres data, then, devres data is freed.

devreses are typed by associated release functions. Some devreses are
better represented by single instance of the type while others need
multiple instances sharing the same release function. Both usages are
supported.

devreses can be grouped using devres group such that a device driver
can easily release acquired resources halfway through initialization
or selectively release resources (e.g. resources for port 1 out of 4
ports).

This patch adds devres core including documentation and the following
managed interfaces.

* alloc/free : devm_kzalloc(), devm_kzfree()
* IO region : devm_request_region(), devm_release_region()
* IRQ : devm_request_irq(), devm_free_irq()
* DMA : dmam_alloc_coherent(), dmam_free_coherent(),
dmam_declare_coherent_memory(), dmam_pool_create(),
dmam_pool_destroy()
* PCI : pcim_enable_device(), pcim_pin_device(), pci_is_managed()
* iomap : devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(),
devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(),
pcim_iomap(), pcim_iounmap()

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/base: check errors

Add lots of return-value checking.

<pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()]
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Driver core: change make_class_name() to take kobjects

This is needed for a future patch for the device code to create the
proper symlinks for devices that are "class devices".

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Driver Core: Add /sys/hypervisor when needed

To have a home for all hypervisors, this patch creates /sys/hypervisor.
A new config option SYS_HYPERVISOR is introduced, which should to be set
by architecture dependent hypervisors (e.g. s390 or Xen).

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Driver Core: remove unused exports

Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Driver core: bus device event delay

split bus_add_device() and send device uevents after sysfs population

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] drivers/base/: proper prototypes

This patch contains the following changes:
- move prototypes to base.h
- sys.c should #include "base.h" for getting the prototype of it's
global function system_bus_init()

Note that hidden in this patch there's a bugfix:

Caller and callee disagreed regarding the return type of
sysdev_shutdown().

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] drivers/base - fix sparse warnings

There are a number of sparse warnings from the latest sparse
snapshot being generated from the drivers/base build. The
main culprits are due to the initialisation functions not
being declared in a header file.

Also, the firmware.c file should include <linux/device.h>
to get the prototype of firmware_register() and
firmware_unregister().

This patch moves the init function declerations from the
init.c file to the base.h, and ensures it is included in
all the relevant c sources. It also adds <linux/device.h>
to the included headers for firmware.c.

The patch does not solve all the sparse errors generated,
but reduces the count significantly.

drivers/base/core.c:161:1: warning: symbol 'devices_subsys' was not declared. Should it be static?
drivers/base/core.c:417:12: warning: symbol 'devices_init' was not declared. Should it be static?
drivers/base/sys.c:253:6: warning: symbol 'sysdev_shutdown' was not declared. Should it be static?
drivers/base/sys.c:326:5: warning: symbol 'sysdev_suspend' was not declared. Should it be static?
drivers/base/sys.c:428:5: warning: symbol 'sysdev_resume' was not declared. Should it be static?
drivers/base/sys.c:450:12: warning: symbol 'system_bus_init' was not declared. Should it be static?
drivers/base/bus.c:133:1: warning: symbol 'bus_subsys' was not declared. Should it be static?
drivers/base/bus.c:667:12: warning: symbol 'buses_init' was not declared. Should it be static?
drivers/base/class.c:759:12: warning: symbol 'classes_init' was not declared. Should it be static?
drivers/base/platform.c:313:12: warning: symbol 'platform_bus_init' was not declared. Should it be static?
drivers/base/cpu.c:110:12: warning: symbol 'cpu_dev_init' was not declared. Should it be static?
drivers/base/firmware.c:17:5: warning: symbol 'firmware_register' was not declared. Should it be static?
drivers/base/firmware.c:23:6: warning: symbol 'firmware_unregister' was not declared. Should it be static?
drivers/base/firmware.c:28:12: warning: symbol 'firmware_init' was not declared. Should it be static?
drivers/base/init.c:28:13: warning: symbol 'driver_init' was not declared. Should it be static?
drivers/base/dmapool.c:174:10: warning: implicit cast from nocast type
drivers/base/attribute_container.c:439:1: warning: symbol 'attribute_container_init' was not declared. Should it be static?
drivers/base/power/runtime.c:76:6: warning: symbol 'dpm_set_power_state' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] driver core: Add the ability to bind drivers to devices from userspace

This adds a single file, "bind", to the sysfs directory of every driver
registered with the driver core. To bind a device to a driver, write
the bus id of the device you wish to bind to that specific driver to the
"bind" file (remember to not add a trailing \n). If that bus id matches
a device on that bus, and it does not currently have a driver bound to
it, the probe sequence will be initiated with that driver and device.

Note, this requires that the driver itself be willing and able to accept
that device (usually through a device id type table). This patch does
not make it possible to override the driver's id table.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] Move device/driver code to drivers/base/dd.c

This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done
for two reasons: One, it's not code related to the bus_type itself; it uses some from
that, some from devices, and some from drivers. And Two, it will make it easier to do
some of the upcoming lock removal on that code..

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
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!