Commit Graph

225 Commits

Author SHA1 Message Date
Thierry Reding
82aa68afa1 thermal: core: Fix thermal zone lookup by ID
When a thermal zone is looked up by an ID and no zone is found matching
that ID, the thermal_zone_get_by_id() function will return a pointer to
the thermal zone list head which isn't actually a valid thermal zone.

This can lead to a subsequent crash because a valid pointer is returned
to the called, but dereferencing that pointer as struct thermal_zone is
not safe.

Fixes: 329b064fbd ("thermal: core: Get thermal zone by id")
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200724170105.2705467-1-thierry.reding@gmail.com
2020-07-24 19:11:47 +02:00
Daniel Lezcano
3f5a2cbe0f thermal: core: Move initialization after core initcall
The generic netlink is initialized at subsys_initcall, so far after
the thermal init routine and the thermal generic netlink family
initialization.

On ŝome platforms, that leads to a memory corruption.

The fix was sent to netdev@ to move the genetlink framework
initialization at core_initcall.

Move the thermal core initialization to postcore level which is very
close to core level.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Link: https://lore.kernel.org/r/20200717164217.18819-2-daniel.lezcano@linaro.org
2020-07-21 10:40:08 +02:00
Daniel Lezcano
d2a89b5283 thermal: netlink: Improve the initcall ordering
The initcalls like to play joke. In our case, the thermal-netlink
initcall is called after the thermal-core initcall but this one sends
a notification before the former is initialized. No issue was spotted,
but it could lead to a memory corruption, so instead of relying on the
core_initcall for the thermal-netlink, let's initialize directly from
the thermal-core init routine, so we have full control of the init
ordering.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Link: https://lore.kernel.org/r/20200717164217.18819-1-daniel.lezcano@linaro.org
2020-07-21 10:40:08 +02:00
Daniel Lezcano
55cdf0a283 thermal: core: Add notifications call in the framework
The generic netlink protocol is implemented but the different
notification functions are not yet connected to the core code.

These changes add the notification calls in the different
corresponding places.

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20200706105538.2159-4-daniel.lezcano@linaro.org
2020-07-07 15:55:22 +02:00
Daniel Lezcano
329b064fbd thermal: core: Get thermal zone by id
The next patch will introduce the generic netlink protocol to handle
events, sampling and command from the thermal framework. In order to
deal with the thermal zone, it uses its unique identifier to
characterize it in the message. Passing an integer is more efficient
than passing an entire string.

This change provides a function returning back a thermal zone pointer
corresponding to the identifier passed as parameter.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20200706105538.2159-2-daniel.lezcano@linaro.org
2020-07-07 15:55:21 +02:00
Daniel Lezcano
3d44a509c1 thermal: core: Add helpers to browse the cdev, tz and governor list
The cdev, tz and governor list, as well as their respective locks are
statically defined in the thermal_core.c file.

In order to give a sane access to these list, like browsing all the
thermal zones or all the cooling devices, let's define a set of
helpers where we pass a callback as a parameter to be called for each
thermal entity.

We keep the self-encapsulation and ensure the locks are correctly
taken when looking at the list.

Acked-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200706105538.2159-1-daniel.lezcano@linaro.org
2020-07-07 15:55:20 +02:00
Andrzej Pietrasiewicz
514acd00f9 thermal: Make thermal_zone_device_is_enabled() available to core only
This function is not needed by drivers.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200703104354.19657-4-andrzej.p@collabora.com
2020-07-07 01:26:07 +02:00
Andrzej Pietrasiewicz
f5e50bf4d3 thermal: Rename set_mode() to change_mode()
set_mode() is only called when tzd's mode is about to change. Actual
setting is performed in thermal_core, in thermal_zone_device_set_mode().
The meaning of set_mode() callback is actually to notify the driver about
the mode being changed and giving the driver a chance to oppose such
change.

To better reflect the purpose of the method rename it to change_mode()

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
[for acerhdf]
Acked-by: Peter Kaestle <peter@piie.net>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-12-andrzej.p@collabora.com
2020-06-29 20:26:39 +02:00
Andrzej Pietrasiewicz
b56bdff78e thermal: core: Stop polling DISABLED thermal devices
Polling DISABLED devices is not desired, as all such "disabled" devices
are meant to be handled by userspace. This patch introduces and uses
should_stop_polling() to decide whether the device should be polled or not.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-10-andrzej.p@collabora.com
2020-06-29 20:26:38 +02:00
Andrzej Pietrasiewicz
7f4957be0d thermal: Use mode helpers in drivers
Use thermal_zone_device_{en|dis}able() and thermal_zone_device_is_enabled().

Consequently, all set_mode() implementations in drivers:

- can stop modifying tzd's "mode" member,
- shall stop taking tzd's lock, as it is taken in the helpers
- shall stop calling thermal_zone_device_update() as it is called in the
helpers
- can assume they are called when the mode truly changes, so checks to
verify that can be dropped

Not providing set_mode() by a driver no longer prevents the core from
being able to set tzd's mode, so the relevant check in mode_store() is
removed.

Other comments:

- acpi/thermal.c: tz->thermal_zone->mode will be updated only after we
return from set_mode(), so use function parameter in thermal_set_mode()
instead, no need to call acpi_thermal_check() in set_mode()
- thermal/imx_thermal.c: regmap writes and mode assignment are done in
thermal_zone_device_{en|dis}able() and set_mode() callback
- thermal/intel/intel_quark_dts_thermal.c: soc_dts_{en|dis}able() are a
part of set_mode() callback, so they don't need to modify tzd->mode, and
don't need to fall back to the opposite mode if unsuccessful, as the return
value will be propagated to thermal_zone_device_{en|dis}able() and
ultimately tzd's member will not be changed in thermal_zone_device_set_mode().
- thermal/of-thermal.c: no need to set zone->mode to DISABLED in
of_parse_thermal_zones() as a tzd is kzalloc'ed so mode is DISABLED anyway

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
[for acerhdf]
Acked-by: Peter Kaestle <peter@piie.net>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-8-andrzej.p@collabora.com
2020-06-29 20:26:36 +02:00
Andrzej Pietrasiewicz
ac5d9ecc74 thermal: Add mode helpers
Prepare for making the drivers not access tzd's private members.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[staticize thermal_zone_device_set_mode()]
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-7-andrzej.p@collabora.com
2020-06-29 20:26:36 +02:00
Andrzej Pietrasiewicz
1ee14820fd thermal: remove get_mode() operation of drivers
get_mode() is now redundant, as the state is stored in struct
thermal_zone_device.

Consequently the "mode" attribute in sysfs can always be visible, because
it is always possible to get the mode from struct tzd.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
[for acerhdf]
Acked-by: Peter Kaestle <peter@piie.net>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-6-andrzej.p@collabora.com
2020-06-29 20:26:35 +02:00
Amit Kucheria
3f0cfea3dd thermal/core: Replace module.h with export.h
Thermal core cannot be modular, remove the unnecessary module.h include
and replace with export.h to handle EXPORT_SYMBOL family of macros.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/33af23406dcdb0c62dae1e6401446b997ccb449f.1589199124.git.amit.kucheria@linaro.org
2020-05-22 18:48:53 +02:00
Amit Kucheria
869495ccf5 thermal/core: Get rid of MODULE_* tags
The thermal framework can no longer be compiled as a module as of
commit 554b3529fe ("thermal/drivers/core: Remove the module Kconfig's
option"). Remove the MODULE_* tags.

Rui is mentioned in the copyright line at the top of the file and the
license is mentioned in the SPDX tags. So no loss of information.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/74339a09a55f8f3d86c4074fc2bf853a302d6186.1589199124.git.amit.kucheria@linaro.org
2020-05-22 18:48:53 +02:00
Daniel Lezcano
44fc73223e thermal: core: Remove pointless debug traces
The last temperature and the current temperature are show via a
dev_debug. The line before, those temperature are also traced.

It is pointless to duplicate the traces for the temperatures,
remove the dev_dbg traces.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Link: https://lore.kernel.org/r/20200331165449.30355-2-daniel.lezcano@linaro.org
2020-04-14 11:41:12 +02:00
Wei Wang
163b00cde7 thermal: Fix deadlock in thermal thermal_zone_device_check
1851799e1d ("thermal: Fix use-after-free when unregistering thermal zone
device") changed cancel_delayed_work to cancel_delayed_work_sync to avoid
a use-after-free issue. However, cancel_delayed_work_sync could be called
insides the WQ causing deadlock.

[54109.642398] c0   1162 kworker/u17:1   D    0 11030      2 0x00000000
[54109.642437] c0   1162 Workqueue: thermal_passive_wq thermal_zone_device_check
[54109.642447] c0   1162 Call trace:
[54109.642456] c0   1162  __switch_to+0x138/0x158
[54109.642467] c0   1162  __schedule+0xba4/0x1434
[54109.642480] c0   1162  schedule_timeout+0xa0/0xb28
[54109.642492] c0   1162  wait_for_common+0x138/0x2e8
[54109.642511] c0   1162  flush_work+0x348/0x40c
[54109.642522] c0   1162  __cancel_work_timer+0x180/0x218
[54109.642544] c0   1162  handle_thermal_trip+0x2c4/0x5a4
[54109.642553] c0   1162  thermal_zone_device_update+0x1b4/0x25c
[54109.642563] c0   1162  thermal_zone_device_check+0x18/0x24
[54109.642574] c0   1162  process_one_work+0x3cc/0x69c
[54109.642583] c0   1162  worker_thread+0x49c/0x7c0
[54109.642593] c0   1162  kthread+0x17c/0x1b0
[54109.642602] c0   1162  ret_from_fork+0x10/0x18
[54109.643051] c0   1162 kworker/u17:2   D    0 16245      2 0x00000000
[54109.643067] c0   1162 Workqueue: thermal_passive_wq thermal_zone_device_check
[54109.643077] c0   1162 Call trace:
[54109.643085] c0   1162  __switch_to+0x138/0x158
[54109.643095] c0   1162  __schedule+0xba4/0x1434
[54109.643104] c0   1162  schedule_timeout+0xa0/0xb28
[54109.643114] c0   1162  wait_for_common+0x138/0x2e8
[54109.643122] c0   1162  flush_work+0x348/0x40c
[54109.643131] c0   1162  __cancel_work_timer+0x180/0x218
[54109.643141] c0   1162  handle_thermal_trip+0x2c4/0x5a4
[54109.643150] c0   1162  thermal_zone_device_update+0x1b4/0x25c
[54109.643159] c0   1162  thermal_zone_device_check+0x18/0x24
[54109.643167] c0   1162  process_one_work+0x3cc/0x69c
[54109.643177] c0   1162  worker_thread+0x49c/0x7c0
[54109.643186] c0   1162  kthread+0x17c/0x1b0
[54109.643195] c0   1162  ret_from_fork+0x10/0x18
[54109.644500] c0   1162 cat             D    0  7766      1 0x00000001
[54109.644515] c0   1162 Call trace:
[54109.644524] c0   1162  __switch_to+0x138/0x158
[54109.644536] c0   1162  __schedule+0xba4/0x1434
[54109.644546] c0   1162  schedule_preempt_disabled+0x80/0xb0
[54109.644555] c0   1162  __mutex_lock+0x3a8/0x7f0
[54109.644563] c0   1162  __mutex_lock_slowpath+0x14/0x20
[54109.644575] c0   1162  thermal_zone_get_temp+0x84/0x360
[54109.644586] c0   1162  temp_show+0x30/0x78
[54109.644609] c0   1162  dev_attr_show+0x5c/0xf0
[54109.644628] c0   1162  sysfs_kf_seq_show+0xcc/0x1a4
[54109.644636] c0   1162  kernfs_seq_show+0x48/0x88
[54109.644656] c0   1162  seq_read+0x1f4/0x73c
[54109.644664] c0   1162  kernfs_fop_read+0x84/0x318
[54109.644683] c0   1162  __vfs_read+0x50/0x1bc
[54109.644692] c0   1162  vfs_read+0xa4/0x140
[54109.644701] c0   1162  SyS_read+0xbc/0x144
[54109.644708] c0   1162  el0_svc_naked+0x34/0x38
[54109.845800] c0   1162 D 720.000s 1->7766->7766 cat [panic]

Fixes: 1851799e1d ("thermal: Fix use-after-free when unregistering thermal zone device")
Cc: stable@vger.kernel.org
Signed-off-by: Wei Wang <wvw@google.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-11-14 22:41:09 +08:00
Amit Kucheria
ae16a688f6 thermal: Initialize thermal subsystem earlier
Now that the thermal framework is built-in, in order to facilitate
thermal mitigation as early as possible in the boot cycle, move the
thermal framework initialization to core_initcall.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/f8ff0ab4a8e9c2eca5a26fb2256365b26cb326ce.1571656015.git.amit.kucheria@linaro.org
2019-11-07 07:00:26 +01:00
Amit Kucheria
f96c8e5015 thermal: Remove netlink support
There are no users of netlink messages for thermal inside the kernel.
Remove the code and adjust the documentation.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/8ff02cf62186c7a54fff325fad40a2e9ca3affa6.1571656014.git.amit.kucheria@linaro.org
2019-11-07 07:00:26 +01:00
Amit Kucheria
67eed44b8a thermal: Add some error messages
When registering a thermal zone device, we currently return -EINVAL in
four cases. This makes it a little hard to debug the real cause of the
failure.

Print some error messages to make it easier for developer to figure out
what happened.

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-09-24 09:56:08 +08:00
Ido Schimmel
1851799e1d thermal: Fix use-after-free when unregistering thermal zone device
thermal_zone_device_unregister() cancels the delayed work that polls the
thermal zone, but it does not wait for it to finish. This is racy with
respect to the freeing of the thermal zone device, which can result in a
use-after-free [1].

Fix this by waiting for the delayed work to finish before freeing the
thermal zone device. Note that thermal_zone_device_set_polling() is
never invoked from an atomic context, so it is safe to call
cancel_delayed_work_sync() that can block.

[1]
[  +0.002221] ==================================================================
[  +0.000064] BUG: KASAN: use-after-free in __mutex_lock+0x1076/0x11c0
[  +0.000016] Read of size 8 at addr ffff8881e48e0450 by task kworker/1:0/17

[  +0.000023] CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.2.0-rc6-custom-02495-g8e73ca3be4af #1701
[  +0.000010] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[  +0.000016] Workqueue: events_freezable_power_ thermal_zone_device_check
[  +0.000012] Call Trace:
[  +0.000021]  dump_stack+0xa9/0x10e
[  +0.000020]  print_address_description.cold.2+0x9/0x25e
[  +0.000018]  __kasan_report.cold.3+0x78/0x9d
[  +0.000016]  kasan_report+0xe/0x20
[  +0.000016]  __mutex_lock+0x1076/0x11c0
[  +0.000014]  step_wise_throttle+0x72/0x150
[  +0.000018]  handle_thermal_trip+0x167/0x760
[  +0.000019]  thermal_zone_device_update+0x19e/0x5f0
[  +0.000019]  process_one_work+0x969/0x16f0
[  +0.000017]  worker_thread+0x91/0xc40
[  +0.000014]  kthread+0x33d/0x400
[  +0.000015]  ret_from_fork+0x3a/0x50

[  +0.000020] Allocated by task 1:
[  +0.000015]  save_stack+0x19/0x80
[  +0.000015]  __kasan_kmalloc.constprop.4+0xc1/0xd0
[  +0.000014]  kmem_cache_alloc_trace+0x152/0x320
[  +0.000015]  thermal_zone_device_register+0x1b4/0x13a0
[  +0.000015]  mlxsw_thermal_init+0xc92/0x23d0
[  +0.000014]  __mlxsw_core_bus_device_register+0x659/0x11b0
[  +0.000013]  mlxsw_core_bus_device_register+0x3d/0x90
[  +0.000013]  mlxsw_pci_probe+0x355/0x4b0
[  +0.000014]  local_pci_probe+0xc3/0x150
[  +0.000013]  pci_device_probe+0x280/0x410
[  +0.000013]  really_probe+0x26a/0xbb0
[  +0.000013]  driver_probe_device+0x208/0x2e0
[  +0.000013]  device_driver_attach+0xfe/0x140
[  +0.000013]  __driver_attach+0x110/0x310
[  +0.000013]  bus_for_each_dev+0x14b/0x1d0
[  +0.000013]  driver_register+0x1c0/0x400
[  +0.000015]  mlxsw_sp_module_init+0x5d/0xd3
[  +0.000014]  do_one_initcall+0x239/0x4dd
[  +0.000013]  kernel_init_freeable+0x42b/0x4e8
[  +0.000012]  kernel_init+0x11/0x18b
[  +0.000013]  ret_from_fork+0x3a/0x50

[  +0.000015] Freed by task 581:
[  +0.000013]  save_stack+0x19/0x80
[  +0.000014]  __kasan_slab_free+0x125/0x170
[  +0.000013]  kfree+0xf3/0x310
[  +0.000013]  thermal_release+0xc7/0xf0
[  +0.000014]  device_release+0x77/0x200
[  +0.000014]  kobject_put+0x1a8/0x4c0
[  +0.000014]  device_unregister+0x38/0xc0
[  +0.000014]  thermal_zone_device_unregister+0x54e/0x6a0
[  +0.000014]  mlxsw_thermal_fini+0x184/0x35a
[  +0.000014]  mlxsw_core_bus_device_unregister+0x10a/0x640
[  +0.000013]  mlxsw_devlink_core_bus_device_reload+0x92/0x210
[  +0.000015]  devlink_nl_cmd_reload+0x113/0x1f0
[  +0.000014]  genl_family_rcv_msg+0x700/0xee0
[  +0.000013]  genl_rcv_msg+0xca/0x170
[  +0.000013]  netlink_rcv_skb+0x137/0x3a0
[  +0.000012]  genl_rcv+0x29/0x40
[  +0.000013]  netlink_unicast+0x49b/0x660
[  +0.000013]  netlink_sendmsg+0x755/0xc90
[  +0.000013]  __sys_sendto+0x3de/0x430
[  +0.000013]  __x64_sys_sendto+0xe2/0x1b0
[  +0.000013]  do_syscall_64+0xa4/0x4d0
[  +0.000013]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[  +0.000017] The buggy address belongs to the object at ffff8881e48e0008
               which belongs to the cache kmalloc-2k of size 2048
[  +0.000012] The buggy address is located 1096 bytes inside of
               2048-byte region [ffff8881e48e0008, ffff8881e48e0808)
[  +0.000007] The buggy address belongs to the page:
[  +0.000012] page:ffffea0007923800 refcount:1 mapcount:0 mapping:ffff88823680d0c0 index:0x0 compound_mapcount: 0
[  +0.000020] flags: 0x200000000010200(slab|head)
[  +0.000019] raw: 0200000000010200 ffffea0007682008 ffffea00076ab808 ffff88823680d0c0
[  +0.000016] raw: 0000000000000000 00000000000d000d 00000001ffffffff 0000000000000000
[  +0.000007] page dumped because: kasan: bad access detected

[  +0.000012] Memory state around the buggy address:
[  +0.000012]  ffff8881e48e0300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  +0.000012]  ffff8881e48e0380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  +0.000012] >ffff8881e48e0400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  +0.000008]                                                  ^
[  +0.000012]  ffff8881e48e0480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  +0.000012]  ffff8881e48e0500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  +0.000007] ==================================================================

Fixes: b1569e99c7 ("ACPI: move thermal trip handling to generic thermal layer")
Reported-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-09-24 09:56:08 +08:00
Yue Hu
adc8749b15 thermal/drivers/core: Use put_device() if device_register() fails
Never directly free @dev after calling device_register(), even if it
returned an error! Always use put_device() to give up the reference
initialized. Clean up the rollback block also.

Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-09-24 09:56:08 +08:00
Daniel Lezcano
57c5b2ec90 thermal/drivers/core: Use governor table to initialize
Now that the governor table is in place and the macro allows to browse the
table, declare the governor so the entry is added in the governor table
in the init section.

The [un]register_thermal_governors function does no longer need to use the
exported [un]register thermal governor's specific function which in turn
call the [un]register_thermal_governor. The governors are fully
self-encapsulated.

The cyclic dependency is no longer needed, remove it.

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-06-27 21:22:14 +08:00
Linus Torvalds
2c45e7fbc9 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux
Pull thermal management updates from Zhang Rui:

 - Remove the 'module' Kconfig option for thermal subsystem framework
   because the thermal framework are required to be ready as early as
   possible to avoid overheat at boot time (Daniel Lezcano)

 - Fix a bug that thermal framework pokes disabled thermal zones upon
   resume (Wei Wang)

  - A couple of cleanups and trivial fixes on int340x thermal drivers
    (Srinivas Pandruvada, Zhang Rui, Sumeet Pawnikar)

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  drivers: thermal: processor_thermal: Downgrade error message
  mlxsw: Remove obsolete dependency on THERMAL=m
  hwmon/drivers/core: Simplify complex dependency
  thermal/drivers/core: Fix typo in the option name
  thermal/drivers/core: Remove depends on THERMAL in Kconfig
  thermal/drivers/core: Remove module unload code
  thermal/drivers/core: Remove the module Kconfig's option
  thermal: core: skip update disabled thermal zones after suspend
  thermal: make device_register's type argument const
  thermal: intel: int340x: processor_thermal_device: simplify to get driver data
  thermal/int3403_thermal: favor _TMP instead of PTYP
2019-05-16 16:16:18 -07:00
Guenter Roeck
b4ab114cc6 thermal: Introduce devm_thermal_of_cooling_device_register
thermal_of_cooling_device_register() and thermal_cooling_device_register()
are typically called from driver probe functions, and
thermal_cooling_device_unregister() is called from remove functions. This
makes both a perfect candidate for device managed functions.

Introduce devm_thermal_of_cooling_device_register(). This function can
also be used to replace thermal_cooling_device_register() by passing a NULL
pointer as device node. The new function requires both struct device *
and struct device_node * as parameters since the struct device_node *
parameter is not always identical to dev->of_node.

Don't introduce a device managed remove function since it is not needed
at this point.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2019-05-14 07:00:30 -07:00
Zhang Rui
6df24c3e81 Merge branches 'thermal-core', 'thermal-built-it' and 'thermal-intel' into next 2019-05-07 21:54:11 +08:00
Daniel Lezcano
77e1dd46a1 thermal/drivers/core: Remove module unload code
Now the thermal core is no longer compiled as a module. Remove the
unloading module code and move the unregister function to the __init
section.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-05-06 20:35:24 +08:00
Wei Wang
ff54bbd1be thermal: core: skip update disabled thermal zones after suspend
It is unnecessary to update disabled thermal zones post suspend and
sometimes leads error/warning in bad behaved thermal drivers.

Signed-off-by: Wei Wang <wvw@google.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-05-06 20:35:11 +08:00
Jean-Francois Dagenais
f991de53a8 thermal: make device_register's type argument const
...because it can be, the buffer is strlcpy'd into a local buffer in a
thermal struct member.

Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2019-05-06 20:35:11 +08:00
Wei Wang
964f4843a4 Thermal: do not clear passive state during system sleep
commit ff140fea84 ("Thermal: handle thermal zone device properly
during system sleep") added PM hook to call thermal zone reset during
sleep. However resetting thermal zone will also clear the passive state
and thus cancel the polling queue which leads the passive cooling device
state not being cleared properly after sleep.

thermal_pm_notify => thermal_zone_device_reset set passive to 0
thermal_zone_trip_update will skip update passive as `old_target ==
instance->target'.
monitor_thermal_zone => thermal_zone_device_set_polling will cancel
tz->poll_queue, so the cooling device state will not be changed
afterwards.

Reported-by: Kame Wang <kamewang@google.com>
Signed-off-by: Wei Wang <wvw@google.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-11-30 16:53:13 +08:00
Lukasz Luba
5be52fccaf thermal: remove unused function parameter
Clean unused parameter from internal framework function.

Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-11-30 16:44:34 +08:00
Jeson Gao
c2b59d279d thermal: core: using power_efficient_wq for thermal worker
For SMP systems, thermal worker should use power_efficient_wq in power
saving mode, that will make scheduler more flexible on selecting an active
core for running work handler to avoid keeping work handler always
running on a single core, that will save some power.

Even if 'power_efficient_wq' relevant configs are disabled
'system_freezable_power_efficient_wq' is identical to system_freezable_wq,
behavior is unchanged.

Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-10-10 21:48:50 +08:00
Dmitry Osipenko
3c58776827 thermal: core: Fix use-after-free in thermal_cooling_device_destroy_sysfs
This patch fixes use-after-free that was detected by KASAN. The bug is
triggered on a CPUFreq driver module unload by freeing 'cdev' on device
unregister and then using the freed structure during of the cdev's sysfs
data destruction. The solution is to unregister the sysfs at first, then
destroy sysfs data and finally release the cooling device.

Cc: <stable@vger.kernel.org> # v4.17+
Fixes: 8ea229511e ("thermal: Add cooling device's statistics in sysfs")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-10-10 11:44:52 +08:00
Lina Iyer
7e3c03817f drivers: thermal: Update license to SPDX format
Update licences format for core thermal files.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-05-30 14:46:17 +08:00
Viresh Kumar
33e678d47d thermal: Shorten name of sysfs callbacks
The naming isn't consistent across all sysfs callbacks in the thermal
core, some have a short name like type_show() and others have long names
like thermal_cooling_device_weight_show(). This patch tries to make it
consistent by shortening the name of sysfs callbacks.

Some of the sysfs files are named similarly for both thermal zone and
cooling device (like: type) and to avoid name clash between their
show/store routines, the cooling device specific sysfs callbacks are
prefixed with "cdev_".

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-05-22 10:07:09 +08:00
Viresh Kumar
8ea229511e thermal: Add cooling device's statistics in sysfs
This extends the sysfs interface for thermal cooling devices and exposes
some pretty useful statistics. These statistics have proven to be quite
useful specially while doing benchmarks related to the task scheduler,
where we want to make sure that nothing has disrupted the test,
specially the cooling device which may have put constraints on the CPUs.
The information exposed here tells us to what extent the CPUs were
constrained by the thermal framework.

The write-only "reset" file is used to reset the statistics.

The read-only "time_in_state_ms" file shows the time (in msec) spent by the
device in the respective cooling states, and it prints one line per
cooling state.

The read-only "total_trans" file shows single positive integer value
showing the total number of cooling state transitions the device has
gone through since the time the cooling device is registered or the time
when statistics were reset last.

The read-only "trans_table" file shows a two dimensional matrix, where
an entry <i,j> (row i, column j) represents the number of transitions
from State_i to State_j.

This is how the directory structure looks like for a single cooling
device:

$ ls -R /sys/class/thermal/cooling_device0/
/sys/class/thermal/cooling_device0/:
cur_state  max_state  power  stats  subsystem  type  uevent

/sys/class/thermal/cooling_device0/power:
autosuspend_delay_ms  runtime_active_time  runtime_suspended_time
control               runtime_status

/sys/class/thermal/cooling_device0/stats:
reset  time_in_state_ms  total_trans  trans_table

This is tested on ARM 64-bit Hisilicon hikey620 board running Ubuntu and
ARM 64-bit Hisilicon hikey960 board running Android.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2018-04-02 21:49:01 +08:00
Christophe Jaillet
9d9ca1f9f0 thermal: core: Fix resources release in error paths in thermal_zone_device_register()
Reorder error handling code in order to fix some resources leaks in some
cases:
   - 'tz' would leak if 'thermal_zone_create_device_groups()' fails
   - memory allocated by 'thermal_zone_create_device_groups()' would leak
     if 'device_register()' fails

With this patch, we now have 2 error handling paths: one before
'device_register()', and one after it.
This is needed because some resources are released in 'thermal_release()'.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2017-08-11 11:34:07 +08:00
Christophe Jaillet
6a6cd25b58 thermal: core: Use the new 'thermal_zone_destroy_device_groups()' helper function
Simplify code by using the new 'thermal_zone_destroy_device_groups()'
helper function.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2017-08-11 11:34:00 +08:00
Icenowy Zheng
039f6cf5b5 thermal: core: fix some format issues on critical shutdown string
The critical shutdown notice string used to have some spaces missing,
which makes it not so pretty.

Add the spaces to satisfy usual English space rules.

Reported-by: Mingcong Bai <jeffbai@aosc.io>
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2017-08-08 17:18:26 +08:00
Colin Ian King
c4b379d064 thermal: core: make thermal_emergency_poweroff static
Making thermal_emergency_poweroff static fixes sparse warning:

  drivers/thermal/thermal_core.c:6: warning: symbol
  'thermal_emergency_poweroff' was not declared. Should it be static?

Fixes: ef1d87e06a ("thermal: core: Add a back up thermal shutdown mechanism")
Acked-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2017-05-23 20:03:35 -07:00
Keerthy
ef1d87e06a thermal: core: Add a back up thermal shutdown mechanism
orderly_poweroff is triggered when a graceful shutdown
of system is desired. This may be used in many critical states of the
kernel such as when subsystems detects conditions such as critical
temperature conditions. However, in certain conditions in system
boot up sequences like those in the middle of driver probes being
initiated, userspace will be unable to power off the system in a clean
manner and leaves the system in a critical state. In cases like these,
the /sbin/poweroff will return success (having forked off to attempt
powering off the system. However, the system overall will fail to
completely poweroff (since other modules will be probed) and the system
is still functional with no userspace (since that would have shut itself
off).

However, there is no clean way of detecting such failure of userspace
powering off the system. In such scenarios, it is necessary for a backup
workqueue to be able to force a shutdown of the system when orderly
shutdown is not successful after a configurable time period.

Reported-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2017-05-05 16:01:45 +08:00
Keerthy
e441fd6866 thermal: core: Allow orderly_poweroff to be called only once
thermal_zone_device_check --> thermal_zone_device_update -->
handle_thermal_trip --> handle_critical_trips --> orderly_poweroff

The above sequence happens every 250/500 mS based on the configuration.
The orderly_poweroff function is getting called every 250/500 mS.
With a full fledged file system it takes at least 5-10 Seconds to
power off gracefully.

In that period due to the thermal_zone_device_check triggering
periodically the thermal work queues bombard with
orderly_poweroff calls multiple times eventually leading to
failures in gracefully powering off the system.

Make sure that orderly_poweroff is called only once.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2017-05-05 16:01:44 +08:00
Zhang Rui
6fefe19f58 Merge branches 'thermal-core', 'thermal-soc', 'thermal-intel' and 'ida-conversion' into next 2017-02-22 15:35:06 +08:00
Jacob von Chorus
f53345e8cf thermal: core: move tz->device.groups cleanup to thermal_release
The device_unregister call in thermal_zone_device_unregister causes the
thermal_zone_device structure to be freed before the call to free the
dynamically allocated attribute groups. This leads to a kernel panic.

Furthermore, the 4 calls to free the trip point attribute structures
occur before the call to unregister the device, leading to a kernel
panic when sysfs attempts to access the attributes to remove them.

Here is an example of a kernel panic when the cpu thermal zones are
removed upon cpu offline:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: strlen+0x0/0x20
<snip>
Call Trace:
   ? kernfs_name_hash+0x17/0x80
   kernfs_find_ns+0x3f/0xd0
   kernfs_remove_by_name_ns+0x36/0xa0
   remove_files.isra.1+0x36/0x70
   sysfs_remove_group+0x44/0x90
   sysfs_remove_groups+0x2e/0x50
   device_remove_attrs+0x5e/0x90
   device_del+0x1ea/0x350
   device_unregister+0x1a/0x60
   thermal_zone_device_unregister+0x1f2/0x210
   pkg_thermal_cpu_offline+0x14f/0x1a0 [x86_pkg_temp_thermal]
   ? kzalloc.constprop.2+0x10/0x10 [x86_pkg_temp_thermal]
   cpuhp_invoke_callback+0x8d/0x3f0
   cpuhp_down_callbacks+0x42/0x80
   cpuhp_thread_fun+0x8b/0xf0
   smpboot_thread_fn+0x110/0x160
   kthread+0x101/0x140
   ? sort_range+0x30/0x30
   ? kthread_park+0x90/0x90
   ret_from_fork+0x25/0x30

This patch moves the kfree calls to clean up the dynamic attributes to
the thermal_class's thermal_zone_device release function.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Tested-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Jacob von Chorus <jacobvonchorus@cwphoto.ca>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2017-01-06 13:04:00 +08:00
Matthew Wilcox
b31ef8285b thermal core: convert ID allocation to IDA
The thermal core does not use the ability to look up pointers by ID, so
convert it from using an IDR to the more space-efficient IDA.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2017-01-04 12:47:28 +08:00
Linus Torvalds
9346116d14 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux
Pull thermal management updates from Zhang Rui:

 - Thermal core code reorganization and cleanup. Two new files are
   created for thermal sysfs I/F code and thermal helper functions
   (Eduardo Valentin).

 - Sanitize hotplug and locking for x86_pkg_temp driver (Thomas
   Gleixner)

 - Update MAINTAINER file for pwm-fan driver and Samsung thermal driver
   (Lukasz Majewski)

 - Fix module auto-load for max77620, tango and db8500 thermal driver
   (Javier Martinez Canillas)

 - Fix a bug that thermal hwmon sysfs I/F returns wrong critical trip
   point temperature value (Krzysztof Kozlowski)

 - Add Skylake PCH 100 series support for intel_pch_thermal driver
   (OGAWA Hirofumi)

 - Small fixes and cleanups for platform thermal drivers (Julia Lawall,
   Luis Henriques, Leo Yan, Stephen Boyd, Shawn Lin, Javi Merino and
   Lukasz Luba)

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (76 commits)
  MAINTAINERS: Samsung: Update maintainer for PWM FAN and SAMSUNG THERMAL
  thermal/x86 pkg temp: Convert to hotplug state machine
  thermal/x86_pkg_temp: Sanitize package management
  thermal/x86_pkg_temp: Move work into package struct
  thermal/x86_pkg_temp: Move work scheduled flag into package struct
  thermal/x86_pkg_temp: Sanitize locking
  thermal/x86_pkg_temp: Cleanup code some more
  thermal/x86_pkg_temp: Cleanup namespace
  thermal/x86_pkg_temp: Get rid of ref counting
  thermal/x86_pkg_temp: Sanitize callback (de)initialization
  thermal/x86_pkg_temp: Replace open coded cpu search
  thermal/x86_pkg_temp: Remove redundant package search
  thermal/x86_pkg_temp: Cleanup thermal interrupt handling
  thermal: hwmon: Properly report critical temperature in sysfs
  devfreq_cooling: pass a pointer to devfreq in the power model callbacks
  devfreq_cooling: make the structs devfreq_cooling_xxx visible for all
  dt-bindings: rockchip-thermal: fix the misleading description
  thermal: rockchip: improve the warning log
  thermal: db8500: Fix module autoload
  thermal: tango: Fix module autoload
  ...
2016-12-13 09:00:28 -08:00
Eduardo Valentin
373f91d125 thermal: core: move slop and offset helpers to thermal_helpers.c
Reorganize code to reflect better placement.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
95e3ed1513 thermal: core: use kzalloc(sizeof(*ptr),...)
As a safety check, this patch changes thermal
core to check for pointer content size, instead of type size,
while allocating memory.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
38e7b549af thermal: core: improve kerneldoc entry of thermal_cooling_device_unregister
Improve description and keep 80 columns limit.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
b659a30d7b thermal: core: remove style warnings and checks
Removing several style issues in thermal code code.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
2a0b4c44ce thermal: core: remove void function return statements
Simply removing useless returns of void functions.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
eb7be329bd thermal: core: standardize line breaking alignment
Pass through the code to remove check suggested by
checkpatch.pl (alignment to parenthesis):
CHECK: Alignment should match open parenthesis

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
5027ba36cd thermal: core: small style fix when checking for __find_governor()
Remove style issue:
CHECK: Comparison to NULL could be written "!__find_governor"
+	if (__find_governor(governor->name) == NULL) {

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
7eb4bd723e thermal: core: remove FSF address in the GPL notice
Simplify the GPL notice by removing the FSF address.
No need to track FSF location in this file.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
81193e2e6b thermal: core: add a comment describing the device management section
comment describing the section with function to handle
registration, unregistration, binding, and unbinding of
thermal devices.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
712afbdfdf thermal: core: add a comment describing the power actor section
Simply marking the power actor section and adding a
comment describing it.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
8772e185f1 thermal: core: add a comment describing the main update loop
Simply marking the main update loop section and adding a
comment describing it.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
106339ab7e thermal: core: move notify to the zone update section
moving the helper function to closer to similar functions.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
4b0d3c2d3b thermal: core: add inline to print_bind_err_msg()
Given that this is simple wrapper, adding the inline flag.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
f502ab8440 thermal: core: move __bind() to where it is used
Moving the helper to closer where it is used.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
9b68ef89c9 thermal: core: fix couple of style issues on __bind() helper
Removing style issues on __bind() and its helpers.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
90f5b5bb7f thermal: core: move bind_tz() to where it is used
Moving the helper to closer where it is used.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
949aad839c thermal: core: move bind_cdev() to where it is used
Moving the helper to closer where it is used.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
f11997fa24 thermal: core: move __unbind() helper to where it is used
Simply moving the helper to closer where it is actually used.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
4f5163fac2 thermal: core: small style fix on __unbind() helper
Simply aligning to parenthesis.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
c30176fc6f thermal: core: move idr handling to device management section
Given that idr is only used to get id for thermal devices
(zones and cooling), makes sense to move the code closer.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
1b4f48494e thermal: core: group functions related to governor handling
Organize thermal core code to group the functions
handling with governor manipulation in one single section.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
cd221c7b63 thermal: core: introduce thermal_helpers.c
Here we have a simple code organization. This patch moves
functions that do not need to handle thermal core internal
data structure to thermal_helpers.c file.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
77dc4f9032 thermal: core: remove a couple of style issues on helpers
Reorganizing the code of helper functions to improve
readability and style, as recommended by checkpatch.pl.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
45cf2ec99c thermal: core: move cooling device sysfs to thermal_sysfs.c
This is a code reorganization, simply to concentrate
the sysfs handling functions in thermal_sysfs.c.

This patch moves the cooling device handling functions.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
99ea2eff91 thermal: core: move to_cooling_device macro to header file
Make the to_cooling_device() macro available across
files in thermal core.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
a369ee88f7 thermal: core: move thermal_zone sysfs to thermal_sysfs.c
This is a code reorganization, simply to concentrate
the code handling sysfs in a specific file: thermal_sysfs.c.

Right now, moving only the sysfs entries of thermal_zone_device.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
72afe8e549 thermal: core: match parenthesis on code alignment
Cosmetic change in the sysfs handling functions, as
recommended by checkpatch.pl.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
09544da9e8 thermal: core: treat correctly the return value of *scanf calls
This patch checks the return value of all calls to *scanf.
The check is to simply match the number of expect inputs.

The current code does not do any recovery in case the
number of treated inputs are different than the expected.
Therefore, keeping the same behavior.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
ba78da443b thermal: core: move to_thermal_zone() macro to header file
Simply making this macro available to other thermal core
files.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
97d2423bd9 thermal: core: split available_policies_show()
This patch creates a helper to build a list of available governors.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
6b885202d7 thermal: core: split policy_store
Similarly to passive_store, policy_store now is split
between thermal core data structure handling and sysfs handling.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
3d0055d2b2 thermal: core: split passive_store
Split passive_store between sysfs handling and thermal
core internal data handling.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
2a4806bf7a thermal: core: remove unnecessary device_remove() calls
Given that cdevs sysfs properties are already registered using
the dev.groups, there is no need to explicitly call device_remove()
for each property.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
4d0fe7490d thermal: core: move trips attributes to tz->device.groups
Finally, move the last thermal zone sysfs attributes to
tz->device.groups: trips attributes. This requires adding a
attribute_group to thermal_zone_device, creating it dynamically, and
then setting all trips attributes in it. The trips attribute is then
added to the tz->device.groups.

As the removal of all attributes are handled by device core, the device
remove calls are not needed anymore.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
e161aefb9a thermal: core: create tz->device.groups dynamically
This is a patch to allow adding groups created dynamically. For now we
create only the existing group. However, this is a preparation to allow
creating trip groups, which are determined only when the number of trips
are known at runtime.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
0a9de81907 thermal: core: move the trip attrs to the tz sysfs I/F section
Code reorganization to keep all the sysfs I/F of a thermal zone in the
same section.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
3bafb5e2a6 thermal: core: fix style on remove_trip_attrs()
Align to parentheses, removing checkpatch warning.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
9d934fc883 thermal: core: remove useless empty line
Fix style problem on create_trip_attrs();

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
1a7e7cc03f thermal: core: move power actor code out of sysfs I/F section
Simply reorganize code to keep only functions of sysfs interface
of thermal zone device together. Therefore, move the power actor code
out of the sysfs I/F section.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
059386f43e thermal: core: improve power actor documentation
Simple improvement on clarity and removal of checkpatch warning
in the documentation of power actor kernel doc.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
3a836bfe9f thermal: core: move passive attr to tz->device.groups
This patch moves the passive attribute to tz->device.groups. Moving the
passive attribute also requires a .is_visible() callback implementation
for its attribute group.

The logic behind the visibility of passive attribute is kept the same.
We only expose the passive attribute if the thermal driver has exposed
at least one passive trip point.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
8baa5dae60 thermal: core: move mode attribute to tz->device.groups
Moving mode attribute to tz->device.groups requires the implementation
of a .is_visible() callback. The condition returned by .is_visible() of
the mode attribute group is kept the same, we allow the attribute to be
visible only if ops->get_mode() is set by the thermal driver.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
66e554bde9 thermal: core: move emul_temp creation to tz->device.groups
emul_temp creation is dependent on a compile time
condition. Moving to tz->device.groups.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
1c600861fa thermal: core: use dev.groups to manage always present tz attributes
Thermal zones attributes are all being created using
device_create_file(). This has the disadvantage of making the code
complicated and sometimes we may miss the cleanup of them.

This patch starts to move the thermal zone sysfs attributes to the
dev.groups, so Linux device core manage them for us. For now, this patch
only moves those attributes are always present regardless of thermal
zone condition.

This change has also the advantage of cleaning up the thermal zone
parameters sysfs entries that are left unclean after device
registration.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
308f726ac8 thermal: core: group device_create_file() calls that are always created
Simple code reorganization to group files that are always created
when registering a thermal zone.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
ef1d8bff72 thermal: core: group thermal_zone DEVICE_ATTR's declarations
Simply reorganize the code to have all DEVICE_ATTR's
in one point in the file.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Eduardo Valentin
54fa38cc2e thermal: core: prevent zones with no types to be registered
There are APIs that rely on tz->type. This patch
prevent thermal zones without it to be registered.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-11-23 10:06:12 +08:00
Johannes Berg
56989f6d85 genetlink: mark families as __ro_after_init
Now genl_register_family() is the only thing (other than the
users themselves, perhaps, but I didn't find any doing that)
writing to the family struct.

In all families that I found, genl_register_family() is only
called from __init functions (some indirectly, in which case
I've add __init annotations to clarifly things), so all can
actually be marked __ro_after_init.

This protects the data structure from accidental corruption.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 16:16:09 -04:00
Johannes Berg
489111e5c2 genetlink: statically initialize families
Instead of providing macros/inline functions to initialize
the families, make all users initialize them statically and
get rid of the macros.

This reduces the kernel code size by about 1.6k on x86-64
(with allyesconfig).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 16:16:09 -04:00
Johannes Berg
a07ea4d994 genetlink: no longer support using static family IDs
Static family IDs have never really been used, the only
use case was the workaround I introduced for those users
that assumed their family ID was also their multicast
group ID.

Additionally, because static family IDs would never be
reserved by the generic netlink code, using a relatively
low ID would only work for built-in families that can be
registered immediately after generic netlink is started,
which is basically only the control family (apart from
the workaround code, which I also had to add code for so
it would reserve those IDs)

Thus, anything other than GENL_ID_GENERATE is flawed and
luckily not used except in the cases I mentioned. Move
those workarounds into a few lines of code, and then get
rid of GENL_ID_GENERATE entirely, making it more robust.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-27 16:16:09 -04:00
Srinivas Pandruvada
0e70f466fb thermal: Enhance thermal_zone_device_update for events
Added one additional parameter to thermal_zone_device_update() to provide
caller with an optional capability to specify reason.
Currently this event is used by user space governor to trigger different
processing based on event code. Also it saves an additional call to read
temperature when the event is received.
The following events are cuurently defined:
- Unspecified event
- New temperature sample
- Trip point violated
- Trip point changed
- thermal device up and down
- thermal device power capability changed

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-09-27 14:35:21 +08:00
Sascha Hauer
060c034a97 thermal: Add support for hardware-tracked trip points
This adds support for hardware-tracked trip points to the device tree
thermal sensor framework.

The framework supports an arbitrary number of trip points. Whenever
the current temperature is updated, the trip points immediately
below and above the current temperature are found. A .set_trips
callback is then called with the temperatures. If there is no trip
point above or below the current temperature, the passed trip
temperature will be -INT_MAX or INT_MAX respectively. In this callback,
the driver should program the hardware such that it is notified
when either of these trip points are triggered. When a trip point
is triggered, the driver should call `thermal_zone_device_update'
for the respective thermal zone. This will cause the trip points
to be updated again.

If .set_trips is not implemented, the framework behaves as before.

This patch is based on an earlier version from Mikko Perttunen
<mikko.perttunen@kapsi.fi>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: linux-pm@vger.kernel.org
Reviewed-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-09-27 14:02:16 +08:00
Rajendra Nayak
4a7069a32c thermal: core: export apis to get slope and offset
Add apis for platform thermal drivers to query for slope and offset
attributes, which might be needed for temperature calculations.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-09-27 14:02:16 +08:00
Michele Di Giorgio
d0b7306d20 thermal: fix race condition when updating cooling device
When multiple thermal zones are bound to the same cooling device, multiple
kernel threads may want to update the cooling device state by calling
thermal_cdev_update(). Having cdev not protected by a mutex can lead to a race
condition. Consider the following situation with two kernel threads k1 and k2:

	    Thread k1				Thread k2
                                    ||
                                    ||  call thermal_cdev_update()
                                    ||      ...
                                    ||      set_cur_state(cdev, target);
    call power_actor_set_power()    ||
        ...                         ||
        instance->target = state;   ||
        cdev->updated = false;      ||
                                    ||      cdev->updated = true;
                                    ||      // completes execution
    call thermal_cdev_update()      ||
        // cdev->updated == true    ||
        return;                     ||
                                    \/
                                    time

k2 has already looped through the thermal instances looking for the deepest
cooling device state and is preempted right before setting cdev->updated to
true. Now, k1 runs, modifies the thermal instance state and sets cdev->updated
to false. Then, k1 is preempted and k2 continues the execution by setting
cdev->updated to true, therefore preventing k1 from performing the update.
Notice that this is not an issue if k2 looks at the instance->target modified by
k1 "after" it is assigned by k1. In fact, in this case the update will happen
anyway and k1 can safely return immediately from thermal_cdev_update().

This may lead to a situation where a thermal governor never updates the cooling
device. For example, this is the case for the step_wise governor: when calling
the function thermal_zone_trip_update(), the governor may always get a new state
equal to the old one (which, however, wasn't notified to the cooling device) and
will therefore skip the update.

CC: Zhang Rui <rui.zhang@intel.com>
CC: Eduardo Valentin <edubezval@gmail.com>
CC: Peter Feuerer <peter@piie.net>
Reported-by: Toby Huang <toby.huang@arm.com>
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
2016-08-08 10:57:39 +08:00
Leo Yan
15333e3af1 thermal: use %d to print S32 parameters
Power allocator's parameters are S32 type, so use %d to print them.

Acked-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2016-04-27 15:54:51 -07:00