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

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>

show more ...

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-b

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>

show more ...

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

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>

show more ...

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

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>

show more ...

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.

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>

show more ...

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 d

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>

show more ...

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_bin

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>

show more ...

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 dri

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>

show more ...

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

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>

show more ...

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 b

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>

show more ...

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@

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>

show more ...

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

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>

show more ...

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

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>

show more ...

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 d

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>

show more ...

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 paral

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>

show more ...

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

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>

show more ...

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.

C

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>

show more ...

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>

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>

show more ...

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@linuxfoun

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>

show more ...

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 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>

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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 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>

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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

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>

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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:
knod

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>

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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@linuxfoundatio

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>

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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 rea

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>

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