Commit Graph

342 Commits

Author SHA1 Message Date
5f46671398 cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown
commit 65650b3513 upstream.

It is incorrect to set the cpufreq syscore shutdown callback pointer
to cpufreq_suspend(), because that function cannot be run in the
syscore stage of system shutdown for two reasons: (a) it may attempt
to carry out actions depending on devices that have already been shut
down at that point and (b) the RCU synchronization carried out by it
may not be able to make progress then.

The latter issue has been present since commit 45975c7d21 ("rcu:
Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds"),
but the former one has been there since commit 90de2a4aa9 ("cpufreq:
suspend cpufreq governors on shutdown") regardless.

Fix that by dropping cpufreq_syscore_ops altogether and making
device_shutdown() call cpufreq_suspend() directly before shutting
down devices, which is along the lines of what system-wide power
management does.

Fixes: 45975c7d21 ("rcu: Define RCU-sched API in terms of RCU for Tree RCU PREEMPT builds")
Fixes: 90de2a4aa9 ("cpufreq: suspend cpufreq governors on shutdown")
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 4.0+ <stable@vger.kernel.org> # 4.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-29 09:17:44 +01:00
5432923a6b driver core: Fix use-after-free and double free on glue directory
commit ac43432cb1 upstream.

There is a race condition between removing glue directory and adding a new
device under the glue dir. It can be reproduced in following test:

CPU1:                                         CPU2:

device_add()
  get_device_parent()
    class_dir_create_and_add()
      kobject_add_internal()
        create_dir()    // create glue_dir

                                              device_add()
                                                get_device_parent()
                                                  kobject_get() // get glue_dir

device_del()
  cleanup_glue_dir()
    kobject_del(glue_dir)

                                                kobject_add()
                                                  kobject_add_internal()
                                                    create_dir() // in glue_dir
                                                      sysfs_create_dir_ns()
                                                        kernfs_create_dir_ns(sd)

      sysfs_remove_dir() // glue_dir->sd=NULL
      sysfs_put()        // free glue_dir->sd

                                                          // sd is freed
                                                          kernfs_new_node(sd)
                                                            kernfs_get(glue_dir)
                                                            kernfs_add_one()
                                                            kernfs_put()

Before CPU1 remove last child device under glue dir, if CPU2 add a new
device under glue dir, the glue_dir kobject reference count will be
increase to 2 via kobject_get() in get_device_parent(). And CPU2 has
been called kernfs_create_dir_ns(), but not call kernfs_new_node().
Meanwhile, CPU1 call sysfs_remove_dir() and sysfs_put(). This result in
glue_dir->sd is freed and it's reference count will be 0. Then CPU2 call
kernfs_get(glue_dir) will trigger a warning in kernfs_get() and increase
it's reference count to 1. Because glue_dir->sd is freed by CPU1, the next
call kernfs_add_one() by CPU2 will fail(This is also use-after-free)
and call kernfs_put() to decrease reference count. Because the reference
count is decremented to 0, it will also call kmem_cache_free() to free
the glue_dir->sd again. This will result in double free.

In order to avoid this happening, we also should make sure that kernfs_node
for glue_dir is released in CPU1 only when refcount for glue_dir kobj is
1 to fix this race.

The following calltrace is captured in kernel 4.14 with the following patch
applied:

commit 726e410979 ("drivers: core: Remove glue dirs from sysfs earlier")

--------------------------------------------------------------------------
[    3.633703] WARNING: CPU: 4 PID: 513 at .../fs/kernfs/dir.c:494
                Here is WARN_ON(!atomic_read(&kn->count) in kernfs_get().
....
[    3.633986] Call trace:
[    3.633991]  kernfs_create_dir_ns+0xa8/0xb0
[    3.633994]  sysfs_create_dir_ns+0x54/0xe8
[    3.634001]  kobject_add_internal+0x22c/0x3f0
[    3.634005]  kobject_add+0xe4/0x118
[    3.634011]  device_add+0x200/0x870
[    3.634017]  _request_firmware+0x958/0xc38
[    3.634020]  request_firmware_into_buf+0x4c/0x70
....
[    3.634064] kernel BUG at .../mm/slub.c:294!
                Here is BUG_ON(object == fp) in set_freepointer().
....
[    3.634346] Call trace:
[    3.634351]  kmem_cache_free+0x504/0x6b8
[    3.634355]  kernfs_put+0x14c/0x1d8
[    3.634359]  kernfs_create_dir_ns+0x88/0xb0
[    3.634362]  sysfs_create_dir_ns+0x54/0xe8
[    3.634366]  kobject_add_internal+0x22c/0x3f0
[    3.634370]  kobject_add+0xe4/0x118
[    3.634374]  device_add+0x200/0x870
[    3.634378]  _request_firmware+0x958/0xc38
[    3.634381]  request_firmware_into_buf+0x4c/0x70
--------------------------------------------------------------------------

Fixes: 726e410979 ("drivers: core: Remove glue dirs from sysfs earlier")
Signed-off-by: Muchun Song <smuchun@gmail.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Link: https://lore.kernel.org/r/20190727032122.24639-1-smuchun@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-19 09:08:06 +02:00
53dedc8d52 kobject: return error code if writing /sys/.../uevent fails
[ Upstream commit df44b47965 ]

Propagate error code back to userspace if writing the /sys/.../uevent
file fails. Before, the write operation always returned with success,
even if we failed to recognize the input string or if we failed to
generate the uevent itself.

With the error codes properly propagated back to userspace, we are
able to react in userspace accordingly by not assuming and awaiting
a uevent that is not delivered.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-02-12 19:46:02 +01:00
2f4da60e21 drivers: core: Remove glue dirs from sysfs earlier
commit 726e410979 upstream.

For devices with a class, we create a "glue" directory between
the parent device and the new device with the class name.

This directory is never "explicitely" removed when empty however,
this is left to the implicit sysfs removal done by kobject_release()
when the object loses its last reference via kobject_put().

This is problematic because as long as it's not been removed from
sysfs, it is still present in the class kset and in sysfs directory
structure.

The presence in the class kset exposes a use after free bug fixed
by the previous patch, but the presence in sysfs means that until
the kobject is released, which can take a while (especially with
kobject debugging), any attempt at re-creating such as binding a
new device for that class/parent pair, will result in a sysfs
duplicate file name error.

This fixes it by instead doing an explicit kobject_del() when
the glue dir is empty, by keeping track of the number of
child devices of the gluedir.

This is made easy by the fact that all glue dir operations are
done with a global mutex, and there's already a function
(cleanup_glue_dir) called in all the right places taking that
mutex that can be enhanced for this. It appears that this was
in fact the intent of the function, but the implementation was
wrong.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Guenter Roeck <groeck@google.com>
Cc: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-06 17:31:37 +01:00
c8692d9f5c driver core: Move device_links_purge() after bus_remove_device()
commit 2ec1615017 upstream.

The current ordering of code in device_del() triggers a WARN_ON()
in device_links_purge(), because of an unexpected link status.

The device_links_unbind_consumers() call in device_release_driver()
has to take place before device_links_purge() for the status of all
links to be correct, so move the device_links_purge() call in
device_del() after the invocation of bus_remove_device() which calls
device_release_driver().

Fixes: 9ed9895370 (driver core: Functional dependencies tracking support)
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-01 09:42:59 +01:00
ab605544f6 drivers/base: stop new probing during shutdown
[ Upstream commit 3297c8fc65 ]

There is a race window in device_shutdown(), which may cause
-1. parent device shut down before child or
-2. no shutdown on a new probing device.

For 1st, taking the following scenario:
         device_shutdown                        new plugin device
  list_del_init(parent_dev);
  spin_unlock(list_lock);
                                                  device_add(child)
                                                  probe child
  shutdown parent_dev
       --> now child is on the tail of devices_kset

For 2nd, taking the following scenario:
         device_shutdown                        new plugin device
                                                  device_add(dev)
  device_lock(dev);
  ...
  device_unlock(dev);
                                                  probe dev
       --> now, the new occurred dev has no opportunity to shutdown

To fix this race issue, just prevent the new probing request. With this
logic, device_shutdown() is more similar to dpm_prepare().

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-26 08:38:04 +02:00
ba0be5973f PM / core: Fix supplier device runtime PM usage counter imbalance
commit 47e5abfb54 upstream.

If a device link is added via device_link_add() by the driver of the
link's consumer device, the supplier's runtime PM usage counter is
going to be dropped by the pm_runtime_put_suppliers() call in
driver_probe_device().  However, in that case it is not incremented
unless the supplier driver is already present and the link is not
stateless.  That leads to a runtime PM usage counter imbalance for
the supplier device in a few cases.

To prevent that from happening, bump up the supplier runtime
PM usage counter in device_link_add() for all links with the
DL_FLAG_PM_RUNTIME flag set that are added at the consumer probe
time.  Use pm_runtime_get_noresume() for that as the callers of
device_link_add() who want the supplier to be resumed by it are
expected to pass DL_FLAG_RPM_ACTIVE in flags to it anyway, but
additionally resume the supplier if the link is added during
consumer driver probe to retain the existing behavior for the
callers depending on it.

Fixes: 21d5c57b37 (PM / runtime: Use device links)
Reported-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: 4.10+ <stable@vger.kernel.org> # 4.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-03 11:24:47 +02:00
c81a6be9da driver core: Don't ignore class_dir_create_and_add() failure.
commit 84d0c27d62 upstream.

syzbot is hitting WARN() at kernfs_add_one() [1].
This is because kernfs_create_link() is confused by previous device_add()
call which continued without setting dev->kobj.parent field when
get_device_parent() failed by memory allocation fault injection.
Fix this by propagating the error from class_dir_create_and_add() to
the calllers of get_device_parent().

[1] https://syzkaller.appspot.com/bug?id=fae0fb607989ea744526d1c082a5b8de6529116f

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+df47f81c226b31d89fb1@syzkaller.appspotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-26 08:06:29 +08:00
c59cce7943 PM / runtime: Update links_count also if !CONFIG_SRCU
commit 433986c2c2 upstream.

Commit baa8809f60 (PM / runtime: Optimize the use of device links)
added an invocation of pm_runtime_drop_link() to __device_link_del().
However there are two variants of that function, one for CONFIG_SRCU and
another for !CONFIG_SRCU, and the commit only modified the former.

Fixes: baa8809f60 (PM / runtime: Optimize the use of device links)
Cc: v4.10+ <stable@vger.kernel.org> # v4.10+
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22 15:42:20 +01:00
7521621e60 Do not disable driver and bus shutdown hook when class shutdown hook is set.
As seen from the implementation of the single class shutdown hook this
is not very sound design.

Rename the class shutdown hook to shutdown_pre to make it clear it runs
before the driver shutdown hook.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 18:02:46 +02:00
1af824f085 Merge branch 'bind_unbind' into driver-core-next
This merges the bind_unbind driver core feature into the
driver-core-next branch.  bind_unbind is a branch so that others can
pull and work off of it safely.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-22 12:00:15 +02:00
57b8ff070f driver core: add devm_device_add_group() and friends
Many drivers create additional driver-specific device attributes when
binding to the device, and providing managed version of
device_create_group() will simplify unbinding and error handling in probe
path for such drivers.

Without managed version driver writers either have to mix manual and
managed resources, which is prone to errors, or open-code this function by
providing a wrapper to device_add_group() and use it with devm_add_action()
or devm_add_action_or_reset().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-22 11:59:23 +02:00
a7670d425b 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>
2017-07-22 11:59:23 +02:00
f77af15165 Add "shutdown" to "struct class".
The TPM class has some common shutdown code that must be executed for
all drivers. This adds some needed functionality for that.

Signed-off-by: Josh Zimmerman <joshz@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Fixes: 74d6b3ceaa ("tpm: fix suspend/resume paths for TPM 2.0")
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-07-07 09:49:24 +10:00
974668417b Merge tag 'driver-core-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
 "Here is the big driver core update for 4.13-rc1.

  The large majority of this is a lot of cleanup of old fields in the
  driver core structures and their remaining usages in random drivers.
  All of those fixes have been reviewed by the various subsystem
  maintainers. There's also some small firmware updates in here, a new
  kobject uevent api interface that makes userspace interaction easier,
  and a few other minor things.

  All of these have been in linux-next for a long while with no reported
  issues"

* tag 'driver-core-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (56 commits)
  arm: mach-rpc: ecard: fix build error
  zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()
  driver-core: remove struct bus_type.dev_attrs
  powerpc: vio_cmo: use dev_groups and not dev_attrs for bus_type
  powerpc: vio: use dev_groups and not dev_attrs for bus_type
  USB: usbip: convert to use DRIVER_ATTR_RW
  s390: drivers: convert to use DRIVER_ATTR_RO/WO
  platform: thinkpad_acpi: convert to use DRIVER_ATTR_RO/RW
  pcmcia: ds: convert to use DRIVER_ATTR_RO
  wireless: ipw2x00: convert to use DRIVER_ATTR_RW
  net: ehea: convert to use DRIVER_ATTR_RO
  net: caif: convert to use DRIVER_ATTR_RO
  TTY: hvc: convert to use DRIVER_ATTR_RW
  PCI: pci-driver: convert to use DRIVER_ATTR_WO
  IB: nes: convert to use DRIVER_ATTR_RW
  HID: hid-core: convert to use DRIVER_ATTR_RO and drv_groups
  arm: ecard: fix dev_groups patch typo
  tty: serdev: use dev_groups and not dev_attrs for bus_type
  sparc: vio: use dev_groups and not dev_attrs for bus_type
  hid: intel-ish-hid: use dev_groups and not dev_attrs for bus_type
  ...
2017-07-03 20:27:48 -07:00
4e75e1d7da driver core: add helper to reuse a device-tree node
Add a helper function to be used when reusing the device-tree node of
another device.

It is fairly common for drivers to reuse the device-tree node of a
parent (or other ancestor) device when creating class or bus devices
(e.g. gpio chips, i2c adapters, iio chips, spi masters, serdev, phys,
usb root hubs). But reusing a device-tree node may cause problems if the
new device is later probed as for example driver core would currently
attempt to reinitialise an already active associated pinmux
configuration.

Other potential issues include the platform-bus code unconditionally
dropping the device-tree node reference in its device destructor,
reinitialisation of other bus-managed resources such as clocks, and the
recently added DMA-setup in driver core.

Note that for most examples above this is currently not an issue as the
devices are never probed, but this is a problem for the USB bus which
has recently gained device-tree support. This was discovered and
worked-around in a rather ad-hoc fashion by commit dc5878abf4 ("usb:
core: move root hub's device node assignment after it is added to bus")
by not setting the of_node pointer until after the root-hub device has
been registered.

Instead we can allow devices to reuse a device-tree node by setting a
flag in their struct device that can be used by core, bus and driver
code to avoid resources from being over-allocated.

Note that the helper also grabs an extra reference to the device node,
which specifically balances the unconditional put in the platform-device
destructor.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:07:32 +02:00
f36776fafb kobject: support passing in variables for synthetic uevents
This patch makes it possible to pass additional arguments in addition
to uevent action name when writing /sys/.../uevent attribute. These
additional arguments are then inserted into generated synthetic uevent
as additional environment variables.

Before, we were not able to pass any additional uevent environment
variables for synthetic uevents. This made it hard to identify such uevents
properly in userspace to make proper distinction between genuine uevents
originating from kernel and synthetic uevents triggered from userspace.
Also, it was not possible to pass any additional information which would
make it possible to optimize and change the way the synthetic uevents are
processed back in userspace based on the originating environment of the
triggering action in userspace. With the extra additional variables, we are
able to pass through this extra information needed and also it makes it
possible to synchronize with such synthetic uevents as they can be clearly
identified back in userspace.

The format for writing the uevent attribute is following:

    ACTION [UUID [KEY=VALUE ...]

There's no change in how "ACTION" is recognized - it stays the same
("add", "change", "remove"). The "ACTION" is the only argument required
to generate synthetic uevent, the rest of arguments, that this patch
adds support for, are optional.

The "UUID" is considered as transaction identifier so it's possible to
use the same UUID value for one or more synthetic uevents in which case
we logically group these uevents together for any userspace listeners.
The "UUID" is expected to be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
format where "x" is a hex digit. The value appears in uevent as
"SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment variable.

The "KEY=VALUE" pairs can contain alphanumeric characters only. It's
possible to define zero or more more pairs - each pair is then delimited
by a space character " ". Each pair appears in synthetic uevents as
"SYNTH_ARG_KEY=VALUE" environment variable. That means the KEY name gains
"SYNTH_ARG_" prefix to avoid possible collisions with existing variables.
To pass the "KEY=VALUE" pairs, it's also required to pass in the "UUID"
part for the synthetic uevent first.

If "UUID" is not passed in, the generated synthetic uevent gains
"SYNTH_UUID=0" environment variable automatically so it's possible to
identify this situation in userspace when reading generated uevent and so
we can still make a difference between genuine and synthetic uevents.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 18:30:51 +02:00
35dbf4efb0 driver core: don't initialize 'parent' in device_add()
'parent' is always overwritten before getting used and there is no need
to initialize it with NULL.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:27:39 +02:00
15c9e10d9a drivers core: remove assert_held_device_hotplug()
The last caller of assert_held_device_hotplug() is gone, so remove it again.

Link: http://lkml.kernel.org/r/20170314125226.16779-3-heiko.carstens@de.ibm.com
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-16 16:56:19 -07:00
174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
3fc2192410 mm: validate device_hotplug is held for memory hotplug
mem_hotplug_begin() assumes that it can set mem_hotplug.active_writer
and run the hotplug process without racing another thread.  Validate
this assumption with a lockdep assertion.

Link: http://lkml.kernel.org/r/148693886229.16345.1770484669403334689.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:53 -08:00
c7334ce814 Revert "driver core: Add deferred_probe attribute to devices in sysfs"
This reverts commit 6751667a29.

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>
2017-01-14 14:09:03 +01:00
64df114887 driver core: Silence device links sphinx warning
Silence this warning emitted by sphinx:
include/linux/device.h:938: warning: No description found for parameter 'links'

While at it, fix typos in comments of device links code.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Silvio Fricke <silvio.fricke@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-05 15:02:20 +01:00
6751667a29 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>
2016-11-10 17:22:23 +01:00
baa8809f60 PM / runtime: Optimize the use of device links
If the device has no links to suppliers that should be used for
runtime PM (links with DEVICE_LINK_PM_RUNTIME set), there is no
reason to walk the list of suppliers for that device during
runtime suspend and resume.

Add a simple mechanism to detect that case and possibly avoid the
extra unnecessary overhead.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31 11:42:51 -06:00
21d5c57b37 PM / runtime: Use device links
Modify the runtime PM framework to use device links to ensure that
supplier devices will not be suspended if any of their consumer
devices are active.

The idea is to reference count suppliers on the consumer's resume
and drop references to them on its suspend.  The information on
whether or not the supplier has been reference counted by the
consumer's (runtime) resume is stored in a new field (rpm_active)
in the link object for each link.

It may be necessary to clean up those references when the
supplier is unbinding and that's why the links whose status is
DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend
and resume code.

The above means that if the consumer device is probed in the
runtime-active state, the supplier has to be resumed and reference
counted by device_link_add() so the code works as expected on its
(runtime) suspend.  There is a new flag, DEVICE_LINK_RPM_ACTIVE,
to tell device_link_add() about that (in which case the caller
is responsible for making sure that the consumer really will
be runtime-active when runtime PM is enabled for it).

The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core
whether or not the link should be used for runtime PM at all.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31 11:42:51 -06:00
9ed9895370 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>
2016-10-31 11:36:20 -06:00
9929780e86 Merge tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
 "Here are the "big" driver core patches for 4.9-rc1. Also in here are a
  number of debugfs fixes that cropped up due to the changes that
  happened in 4.8 for that filesystem. Overall, nothing major, just a
  few fixes and cleanups.

  All of these have been in linux-next with no reported issues"

* tag 'driver-core-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (23 commits)
  drivers: dma-coherent: Move spinlock in dma_alloc_from_coherent()
  drivers: dma-coherent: Fix DMA coherent size for less than page
  MAINTAINERS: extend firmware_class maintainer list
  debugfs: propagate release() call result
  driver-core: platform: Catch errors from calls to irq_get_irq_data
  sysfs print name of undiscoverable attribute group
  carl9170: fix debugfs crashes
  b43legacy: fix debugfs crash
  b43: fix debugfs crash
  debugfs: introduce a public file_operations accessor
  device core: Remove deprecated create_singlethread_workqueue
  drivers/base dmam_declare_coherent_memory leaks
  platform: don't return 0 from platform_get_irq[_byname]() on error
  cpu: clean up register_cpu func
  dma-mapping: use vma_pages().
  drivers: dma-coherent: use vma_pages().
  attribute_container: Fix typo
  base: soc: make it explicitly non-modular
  drivers: base: dma-mapping: page align the size when unmap_kernel_range
  platform driver: fix use-after-free in platform_device_del()
  ...
2016-10-03 20:03:24 -07:00
cebf8fd169 driver core: fix race between creating/querying glue dir and its cleanup
The global mutex of 'gdp_mutex' is used to serialize creating/querying
glue dir and its cleanup. Turns out it isn't a perfect way because
part(kobj_kset_leave()) of the actual cleanup action() is done inside
the release handler of the glue dir kobject. That means gdp_mutex has
to be held before releasing the last reference count of the glue dir
kobject.

This patch moves glue dir's cleanup after kobject_del() in device_del()
for avoiding the race.

Cc: Yijing Wang <wangyijing@huawei.com>
Reported-by: Chandra Sekhar Lingutla <clingutla@codeaurora.org>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31 15:13:55 +02:00
478573c93a driver core: Don't leak secondary fwnode on device removal
If device_add_property_set() is called for a device, a secondary fwnode
is allocated and assigned to the device but currently not freed once the
device is removed.

This can be triggered on Apple Macs if a Thunderbolt device is plugged
in on boot since Apple's NHI EFI driver sets a number of properties for
that device which are leaked on unplug.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31 00:28:29 +02:00
55f89a8a45 driver core: Do not overwrite secondary fwnode with NULL if it is set
If multiple devices share single firmware node like it is case with MFD
devices, the same firmware node (ACPI) is assigned to all of them. The
function also modifies the shared firmware node in order to preserve
secondary firmware node of the device in question.

If the new device which is sharing the firmware node does not have
secondary node it will be NULL which will be assigned to the secondary node
of the shared firmware node losing all built-in properties.

Prevent this by setting the secondary firmware node only if the replacement
is non-NULL.

Print also warning if someone tries to overwrite secondary node that has
already been assigned.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-07 02:29:23 +01:00
56f2de81e0 of: to support binding numa node to specified device in devicetree
For now, in function device_add, the new device will be forced to
inherit the numa node of its parent. But this will override the device's
numa node which configured in devicetree.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 22:11:50 -07:00
ae98207309 Merge tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
 "From the number of commits perspective, the biggest items are ACPICA
  and cpufreq changes with the latter taking the lead (over 50 commits).

  On the cpufreq front, there are many cleanups and minor fixes in the
  core and governors, driver updates etc.  We also have a new cpufreq
  driver for Mediatek MT8173 chips.

  ACPICA mostly updates its debug infrastructure and adds a number of
  fixes and cleanups for a good measure.

  The Operating Performance Points (OPP) framework is updated with new
  DT bindings and support for them among other things.

  We have a few updates of the generic power domains framework and a
  reorganization of the ACPI device enumeration code and bus type
  operations.

  And a lot of fixes and cleanups all over.

  Included is one branch from the MFD tree as it contains some
  PM-related driver core and ACPI PM changes a few other commits are
  based on.

  Specifics:

   - ACPICA update to upstream revision 20150818 including method
     tracing extensions to allow more in-depth AML debugging in the
     kernel and a number of assorted fixes and cleanups (Bob Moore, Lv
     Zheng, Markus Elfring).

   - ACPI sysfs code updates and a documentation update related to AML
     method tracing (Lv Zheng).

   - ACPI EC driver fix related to serialized evaluations of _Qxx
     methods and ACPI tools updates allowing the EC userspace tool to be
     built from the kernel source (Lv Zheng).

   - ACPI processor driver updates preparing it for future introduction
     of CPPC support and ACPI PCC mailbox driver updates (Ashwin
     Chaugule).

   - ACPI interrupts enumeration fix for a regression related to the
     handling of IRQ attribute conflicts between MADT and the ACPI
     namespace (Jiang Liu).

   - Fixes related to ACPI device PM (Mika Westerberg, Srinidhi
     Kasagar).

   - ACPI device registration code reorganization to separate the
     sysfs-related code and bus type operations from the rest (Rafael J
     Wysocki).

   - Assorted cleanups in the ACPI core (Jarkko Nikula, Mathias Krause,
     Andy Shevchenko, Rafael J Wysocki, Nicolas Iooss).

   - ACPI cpufreq driver and ia64 cpufreq driver fixes and cleanups (Pan
     Xinhui, Rafael J Wysocki).

   - cpufreq core cleanups on top of the previous changes allowing it to
     preseve its sysfs directories over system suspend/resume (Viresh
     Kumar, Rafael J Wysocki, Sebastian Andrzej Siewior).

   - cpufreq fixes and cleanups related to governors (Viresh Kumar).

   - cpufreq updates (core and the cpufreq-dt driver) related to the
     turbo/boost mode support (Viresh Kumar, Bartlomiej Zolnierkiewicz).

   - New DT bindings for Operating Performance Points (OPP), support for
     them in the OPP framework and in the cpufreq-dt driver plus related
     OPP framework fixes and cleanups (Viresh Kumar).

   - cpufreq powernv driver updates (Shilpasri G Bhat).

   - New cpufreq driver for Mediatek MT8173 (Pi-Cheng Chen).

   - Assorted cpufreq driver (speedstep-lib, sfi, integrator) cleanups
     and fixes (Abhilash Jindal, Andrzej Hajda, Cristian Ardelean).

   - intel_pstate driver updates including Skylake-S support, support
     for enabling HW P-states per CPU and an additional vendor bypass
     list entry (Kristen Carlson Accardi, Chen Yu, Ethan Zhao).

   - cpuidle core fixes related to the handling of coupled idle states
     (Xunlei Pang).

   - intel_idle driver updates including Skylake Client support and
     support for freeze-mode-specific idle states (Len Brown).

   - Driver core updates related to power management (Andy Shevchenko,
     Rafael J Wysocki).

   - Generic power domains framework fixes and cleanups (Jon Hunter,
     Geert Uytterhoeven, Rajendra Nayak, Ulf Hansson).

   - Device PM QoS framework update to allow the latency tolerance
     setting to be exposed to user space via sysfs (Mika Westerberg).

   - devfreq support for PPMUv2 in Exynos5433 and a fix for an incorrect
     exynos-ppmu DT binding (Chanwoo Choi, Javier Martinez Canillas).

   - System sleep support updates (Alan Stern, Len Brown, SungEun Kim).

   - rockchip-io AVS support updates (Heiko Stuebner).

   - PM core clocks support fixup (Colin Ian King).

   - Power capping RAPL driver update including support for Skylake H/S
     and Broadwell-H (Radivoje Jovanovic, Seiichi Ikarashi).

   - Generic device properties framework fixes related to the handling
     of static (driver-provided) property sets (Andy Shevchenko).

   - turbostat and cpupower updates (Len Brown, Shilpasri G Bhat,
     Shreyas B Prabhu)"

* tag 'pm+acpi-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (180 commits)
  cpufreq: speedstep-lib: Use monotonic clock
  cpufreq: powernv: Increase the verbosity of OCC console messages
  cpufreq: sfi: use kmemdup rather than duplicating its implementation
  cpufreq: drop !cpufreq_driver check from cpufreq_parse_governor()
  cpufreq: rename cpufreq_real_policy as cpufreq_user_policy
  cpufreq: remove redundant 'policy' field from user_policy
  cpufreq: remove redundant 'governor' field from user_policy
  cpufreq: update user_policy.* on success
  cpufreq: use memcpy() to copy policy
  cpufreq: remove redundant CPUFREQ_INCOMPATIBLE notifier event
  cpufreq: mediatek: Add MT8173 cpufreq driver
  dt-bindings: mediatek: Add MT8173 CPU DVFS clock bindings
  PM / Domains: Fix typo in description of genpd_dev_pm_detach()
  PM / Domains: Remove unusable governor dummies
  PM / Domains: Make pm_genpd_init() available to modules
  PM / domains: Align column headers and data in pm_genpd_summary output
  powercap / RAPL: disable the 2nd power limit properly
  tools: cpupower: Fix error when running cpupower monitor
  PM / OPP: Drop unlikely before IS_ERR(_OR_NULL)
  PM / OPP: Fix static checker warning (broken 64bit big endian systems)
  ...
2015-09-01 19:45:46 -07:00
17e6b00ac4 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "This updated pull request does not contain the last few GIC related
  patches which were reported to cause a regression.  There is a fix
  available, but I let it breed for a couple of days first.

  The irq departement provides:

   - new infrastructure to support non PCI based MSI interrupts
   - a couple of new irq chip drivers
   - the usual pile of fixlets and updates to irq chip drivers
   - preparatory changes for removal of the irq argument from interrupt
     flow handlers
   - preparatory changes to remove IRQF_VALID"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits)
  irqchip/imx-gpcv2: IMX GPCv2 driver for wakeup sources
  irqchip: Add bcm2836 interrupt controller for Raspberry Pi 2
  irqchip: Add documentation for the bcm2836 interrupt controller
  irqchip/bcm2835: Add support for being used as a second level controller
  irqchip/bcm2835: Refactor handle_IRQ() calls out of MAKE_HWIRQ
  PCI: xilinx: Fix typo in function name
  irqchip/gic: Ensure gic_cpu_if_up/down() programs correct GIC instance
  irqchip/gic: Only allow the primary GIC to set the CPU map
  PCI/MSI: pci-xgene-msi: Consolidate chained IRQ handler install/remove
  unicore32/irq: Prepare puv3_gpio_handler for irq argument removal
  tile/pci_gx: Prepare trio_handle_level_irq for irq argument removal
  m68k/irq: Prepare irq handlers for irq argument removal
  C6X/megamode-pic: Prepare megamod_irq_cascade for irq argument removal
  blackfin: Prepare irq handlers for irq argument removal
  arc/irq: Prepare idu_cascade_isr for irq argument removal
  sparc/irq: Use access helper irq_data_get_affinity_mask()
  sparc/irq: Use helper irq_data_get_irq_handler_data()
  parisc/irq: Use access helper irq_data_get_affinity_mask()
  mn10300/irq: Use access helper irq_data_get_affinity_mask()
  irqchip/i8259: Prepare i8259_irq_dispatch for irq argument removal
  ...
2015-09-01 14:33:35 -07:00
52cdbdd498 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>
2015-08-05 17:07:19 -07:00
3d060aeb72 driver core: implement device_for_each_child_reverse()
The new function device_for_each_child_reverse() is helpful to traverse the
registered devices in a reversed order, e.g. in the case when an operation on
each device should be done first on the last added device, then on one before
last and so on.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-07-28 08:50:42 +01:00
4a7cc83167 genirq/MSI: Move msi_list from struct pci_dev to struct device
Move msi_list from struct pci_dev into struct device, so we can
support non-PCI-device based generic MSI interrupts.

msi_list is now conditional under CONFIG_GENERIC_MSI_IRQ, which is
selected from CONFIG_PCI_MSI, so no functional change for PCI MSI
users.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Reviewed-by: Yijing Wang <wangyijing@huawei.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Stuart Yoder <stuart.yoder@freescale.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Alexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/1436428847-8886-10-git-send-email-jiang.liu@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-22 18:37:43 +02:00
a29fd614a6 drivers/base/core.c: use strreplace()
This eliminates a little .text and avoids repeating the strchr call when
we meet a '!' (which will happen at least once).

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25 17:00:40 -07:00
2481bc7528 Merge tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
 "These are mostly fixes and cleanups all over, although there are a few
  items that sort of fall into the new feature category.

  First off, we have new callbacks for PM domains that should help us to
  handle some issues related to device initialization in a better way.

  There also is some consolidation in the unified device properties API
  area allowing us to use that inferface for accessing data coming from
  platform initialization code in addition to firmware-provided data.

  We have some new device/CPU IDs in a few drivers, support for new
  chips and a new cpufreq driver too.

  Specifics:

   - Generic PM domains support update including new PM domain callbacks
     to handle device initialization better (Russell King, Rafael J
     Wysocki, Kevin Hilman)

   - Unified device properties API update including a new mechanism for
     accessing data provided by platform initialization code (Rafael J
     Wysocki, Adrian Hunter)

   - ARM cpuidle update including ARM32/ARM64 handling consolidation
     (Daniel Lezcano)

   - intel_idle update including support for the Silvermont Core in the
     Baytrail SOC and for the Airmont Core in the Cherrytrail and
     Braswell SOCs (Len Brown, Mathias Krause)

   - New cpufreq driver for Hisilicon ACPU (Leo Yan)

   - intel_pstate update including support for the Knights Landing chip
     (Dasaratharaman Chandramouli, Kristen Carlson Accardi)

   - QorIQ cpufreq driver update (Tang Yuantian, Arnd Bergmann)

   - powernv cpufreq driver update (Shilpasri G Bhat)

   - devfreq update including Tegra support changes (Tomeu Vizoso,
     MyungJoo Ham, Chanwoo Choi)

   - powercap RAPL (Running-Average Power Limit) driver update including
     support for Intel Broadwell server chips (Jacob Pan, Mathias Krause)

   - ACPI device enumeration update related to the handling of the
     special PRP0001 device ID allowing DT-style 'compatible' property
     to be used for ACPI device identification (Rafael J Wysocki)

   - ACPI EC driver update including limited _DEP support (Lan Tianyu,
     Lv Zheng)

   - ACPI backlight driver update including a new mechanism to allow
     native backlight handling to be forced on non-Windows 8 systems and
     a new quirk for Lenovo Ideapad Z570 (Aaron Lu, Hans de Goede)

   - New Windows Vista compatibility quirk for Sony VGN-SR19XN (Chen Yu)

   - Assorted ACPI fixes and cleanups (Aaron Lu, Martin Kepplinger,
     Masanari Iida, Mika Westerberg, Nan Li, Rafael J Wysocki)

   - Fixes related to suspend-to-idle for the iTCO watchdog driver and
     the ACPI core system suspend/resume code (Rafael J Wysocki, Chen Yu)

   - PM tracing support for the suspend phase of system suspend/resume
     transitions (Zhonghui Fu)

   - Configurable delay for the system suspend/resume testing facility
     (Brian Norris)

   - PNP subsystem cleanups (Peter Huewe, Rafael J Wysocki)"

* tag 'pm+acpi-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  ACPI / scan: Fix NULL pointer dereference in acpi_companion_match()
  ACPI / scan: Rework modalias creation when "compatible" is present
  intel_idle: mark cpu id array as __initconst
  powercap / RAPL: mark rapl_ids array as __initconst
  powercap / RAPL: add ID for Broadwell server
  intel_pstate: Knights Landing support
  intel_pstate: remove MSR test
  cpufreq: fix qoriq uniprocessor build
  ACPI / scan: Take the PRP0001 position in the list of IDs into account
  ACPI / scan: Simplify acpi_match_device()
  ACPI / scan: Generalize of_compatible matching
  device property: Introduce firmware node type for platform data
  device property: Make it possible to use secondary firmware nodes
  PM / watchdog: iTCO: stop watchdog during system suspend
  cpufreq: hisilicon: add acpu driver
  ACPI / EC: Call acpi_walk_dep_device_list() after installing EC opregion handler
  cpufreq: powernv: Report cpu frequency throttling
  intel_idle: Add support for the Airmont Core in the Cherrytrail and Braswell SOCs
  intel_idle: Update support for Silvermont Core in Baytrail SOC
  PM / devfreq: tegra: Register governor on module init
  ...
2015-04-14 20:21:54 -07:00
97badf873a device property: Make it possible to use secondary firmware nodes
Add a secondary pointer to struct fwnode_handle so as to make it
possible for a device to have two firmware nodes associated with
it at the same time, for example, an ACPI node and a node with
a set of properties provided by platform initialization code.

In the future that will allow device property lookup to fall back
from the primary firmware node to the secondary one if the given
property is not present there to make it easier to provide defaults
for device properties used by device drivers.

Introduce two helper routines, set_primary_fwnode() and
set_secondary_fwnode() allowing callers to add a primary/secondary
firmware node to the given device in such a way that

 (1) If there's only one firmware node for that device, it will be
     pointed to by the device's firmware node pointer.
 (2) If both the primary and secondary firmware nodes are present,
     the primary one will be pointed to by the device's firmware
     node pointer, while the secondary one will be pointed to by the
     primary node's secondary pointer.
 (3) If one of these nodes is removed (by calling one of the new
     nelpers with NULL as the second argument), the other one will
     be preserved.

Make ACPI use set_primary_fwnode() for attaching its firmware nodes
to devices.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-03 23:23:37 +02:00
5590f3196b drivers/core/of: Add symlink to device-tree from devices with an OF node
So I've been annoyed lately with having a bunch of devices such as i2c
eeproms (for use by VPDs, server world !) and other bits and pieces that
I want to be able to identify from userspace, and possibly provide
additional data about from FW.

Basically, it boils down to correlating the sysfs device with the OF
tree device node, so that user space can use device-tree info such as
additional "location" or "label" (or whatever else we can come up with)
propreties to identify a given device, or get some attributes of use
about it, etc...

Now, so far, we've done that in some subsystem in a fairly ad-hoc basis
using "devspec" properties. For example, PCI creates them if it can
correlate the probed device with a DT node. Some powerpc specific busses
do that too.

However, i2c doesn't and it would be nice to have something more generic
since technically any device can have a corresponding device tree node.

This patch adds an "of_node" symlink to devices that have a non-NULL
dev->of_node pointer, the patch is pretty trivial and seems to work just
fine for me.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 14:56:58 +01:00
5f0163a5ee driver core: Delete an unnecessary check before the function call "put_device"
The put_device() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-25 13:52:35 +01:00
d1f1052c52 device: Change dev_<level> logging functions to return void
No caller or macro uses the return value so make all
the functions return void.

Compiled x86 allyesconfig and defconfig w/o CONFIG_PRINTK

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-26 15:57:59 -08:00
e6b5be2be4 Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00
0cd75047de driver core: fix race with userland in device_add()
bus_add_device() should be called before devtmpfs_create_node(), so when
userland application opens device from devtmpfs, it wouldn't get ENODEV
from kernel, because device_add() wasn't completed.

Signed-off-by: Sergey Klyaus <Sergey.Klyaus@Tune-IT.Ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07 11:14:57 -08:00
e4a60d1390 sysfs: driver core: Fix glue dir race condition by gdp_mutex
There is a race condition when removing glue directory.
It can be reproduced in following test:

path 1: Add first child device
device_add()
    get_device_parent()
            /*find parent from glue_dirs.list*/
            list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
                    if (k->parent == parent_kobj) {
                            kobj = kobject_get(k);
                            break;
                    }
            ....
            class_dir_create_and_add()

path2: Remove last child device under glue dir
device_del()
    cleanup_device_parent()
            cleanup_glue_dir()
                    kobject_put(glue_dir);

If path2 has been called cleanup_glue_dir(), but not
call kobject_put(glue_dir), the glue dir is still
in parent's kset list. Meanwhile, path1 find the glue
dir from the glue_dirs.list. Path2 may release glue dir
before path1 call kobject_get(). So kernel will report
the warning and bug_on.

This is a "classic" problem we have of a kref in a list
that can be found while the last instance could be removed
at the same time.

This patch reuse gdp_mutex to fix this race condition.

The following calltrace is captured in kernel 3.4, but
the latest kernel still has this bug.

-----------------------------------------------------
<4>[ 3965.441471] WARNING: at ...include/linux/kref.h:41 kobject_get+0x33/0x40()
<4>[ 3965.441474] Hardware name: Romley
<4>[ 3965.441475] Modules linked in: isd_iop(O) isd_xda(O)...
...
<4>[ 3965.441605] Call Trace:
<4>[ 3965.441611]  [<ffffffff8103717a>] warn_slowpath_common+0x7a/0xb0
<4>[ 3965.441615]  [<ffffffff810371c5>] warn_slowpath_null+0x15/0x20
<4>[ 3965.441618]  [<ffffffff81215963>] kobject_get+0x33/0x40
<4>[ 3965.441624]  [<ffffffff812d1e45>] get_device_parent.isra.11+0x135/0x1f0
<4>[ 3965.441627]  [<ffffffff812d22d4>] device_add+0xd4/0x6d0
<4>[ 3965.441631]  [<ffffffff812d0dbc>] ? dev_set_name+0x3c/0x40
....
<2>[ 3965.441912] kernel BUG at ..../fs/sysfs/group.c:65!
<4>[ 3965.441915] invalid opcode: 0000 [#1] SMP
...
<4>[ 3965.686743]  [<ffffffff811a677e>] sysfs_create_group+0xe/0x10
<4>[ 3965.686748]  [<ffffffff810cfb04>] blk_trace_init_sysfs+0x14/0x20
<4>[ 3965.686753]  [<ffffffff811fcabb>] blk_register_queue+0x3b/0x120
<4>[ 3965.686756]  [<ffffffff812030bc>] add_disk+0x1cc/0x490
....
-------------------------------------------------------

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.com>
Cc: <stable@vger.kernel.org> #3.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07 08:17:43 -08:00
23971bdfff Merge tag 'iommu-updates-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
 "This pull-request includes:

   - change in the IOMMU-API to convert the former iommu_domain_capable
     function to just iommu_capable

   - various fixes in handling RMRR ranges for the VT-d driver (one fix
     requires a device driver core change which was acked by Greg KH)

   - the AMD IOMMU driver now assigns and deassigns complete alias
     groups to fix issues with devices using the wrong PCI request-id

   - MMU-401 support for the ARM SMMU driver

   - multi-master IOMMU group support for the ARM SMMU driver

   - various other small fixes all over the place"

* tag 'iommu-updates-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (41 commits)
  iommu/vt-d: Work around broken RMRR firmware entries
  iommu/vt-d: Store bus information in RMRR PCI device path
  iommu/vt-d: Only remove domain when device is removed
  driver core: Add BUS_NOTIFY_REMOVED_DEVICE event
  iommu/amd: Fix devid mapping for ivrs_ioapic override
  iommu/irq_remapping: Fix the regression of hpet irq remapping
  iommu: Fix bus notifier breakage
  iommu/amd: Split init_iommu_group() from iommu_init_device()
  iommu: Rework iommu_group_get_for_pci_dev()
  iommu: Make of_device_id array const
  amd_iommu: do not dereference a NULL pointer address.
  iommu/omap: Remove omap_iommu unused owner field
  iommu: Remove iommu_domain_has_cap() API function
  IB/usnic: Convert to use new iommu_capable() API function
  vfio: Convert to use new iommu_capable() API function
  kvm: iommu: Convert to use new iommu_capable() API function
  iommu/tegra: Convert to iommu_capable() API function
  iommu/msm: Convert to iommu_capable() API function
  iommu/vt-d: Convert to iommu_capable() API function
  iommu/fsl: Convert to iommu_capable() API function
  ...
2014-10-15 07:23:49 +02:00
599bad38cf driver core: Add BUS_NOTIFY_REMOVED_DEVICE event
This event closes an important gap in the bus notifiers.
There is already the BUS_NOTIFY_DEL_DEVICE event, but that
is sent when the device is still bound to its device driver.

This is too early for the IOMMU code to destroy any mappings
for the device, as they might still be in use by the driver.

The new BUS_NOTIFY_REMOVED_DEVICE event introduced with this
patch closes this gap as it is sent when the device is
already unbound from its device driver and almost completly
removed from the driver core.

With this event the IOMMU code can safely destroy any
mappings and other data structures when a device is removed.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Jerry Hoemann <jerry.hoemann@hp.com>
2014-10-02 11:14:34 +02:00
655e5b7c03 drivers/base: Fix length checks in create_syslog_header()/dev_vprintk_emit()
snprintf() returns the number of bytes that could have been written
(excluding the null), not the actual number of bytes written.  Given a
long enough subsystem or device name, these functions will advance
beyond the end of the on-stack buffer in dev_vprintk_exit(), resulting
in an information leak or stack corruption.  I don't know whether such
a long name is currently possible.

In case snprintf() returns a value >= the buffer size, do not add
structured logging information.  Also WARN if this happens, so we can
fix the driver or increase the buffer size.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 22:55:15 -07:00
33ac1257ff sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
All device_schedule_callback_owner() users are converted to use
device_remove_file_self().  Remove now unused
{sysfs|device}_schedule_callback_owner().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16 11:56:33 -07:00