linux-toradex.git/drivers/cpufreq/acpi-cpufreq.c, branch v4.4.10

cpufreq: acpi_cpufreq: prevent crash on reading freqdomain_cpus

2015-10-08T19:47:13+00:00

When freqdomain_cpus attribute is read from an offlined cpu, it will
cause crash. This change prevents calling cpufreq_show_cpus when
policy driver_data is NULL.

Crash info:

[  170.814949] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[  170.814990] IP: [] _find_next_bit.part.0+0x10/0x70
[  170.815021] PGD 227d30067 PUD 229e56067 PMD 0
[  170.815043] Oops: 0000 [#2] SMP
[  170.816022] CPU: 3 PID: 3121 Comm: cat Tainted: G      D    OE   4.3.0-rc3+ #33
...
...
[  170.816657] Call Trace:
[  170.816672]  [] ? find_next_bit+0x15/0x20
[  170.816696]  [] cpufreq_show_cpus+0x5c/0xd0
[  170.816722]  [] show_freqdomain_cpus+0x19/0x20 [acpi_cpufreq]
[  170.816749]  [] show+0x3b/0x60
[  170.816769]  [] sysfs_kf_seq_show+0xbc/0x130
[  170.816793]  [] kernfs_seq_show+0x23/0x30
[  170.816816]  [] seq_read+0xec/0x390
[  170.816837]  [] kernfs_fop_read+0x10a/0x160
[  170.816861]  [] __vfs_read+0x37/0x100
[  170.816883]  [] ? security_file_permission+0xa0/0xc0
[  170.816909]  [] vfs_read+0x83/0x130
[  170.816930]  [] SyS_read+0x55/0xc0
...
...
[  170.817185] ---[ end trace bc6eadf82b2b965a ]---

Signed-off-by: Srinivas Pandruvada 
Acked-by: Viresh Kumar 
Cc: 4.2+  # 4.2+
Signed-off-by: Rafael J. Wysocki

cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()

2015-09-16T00:17:49+00:00

cpufreq_cpu_get() called by get_cur_freq_on_cpu() is overkill,
because the ->get() callback is always invoked in a context in
which all of the conditions checked by cpufreq_cpu_get() are
guaranteed to be satisfied.

Use cpufreq_cpu_get_raw() instead of it and drop the
corresponding cpufreq_cpu_put() from get_cur_freq_on_cpu().

Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar

cpufreq: acpi-cpufreq: Fix up the handling of cpb sysfs attribute

2015-07-22T20:12:10+00:00

The cpb sysfs attribute is only exposed by the ACPI cpufreq driver
after a runtime check.  For this purpose, the driver keeps a NULL
placeholder in its table of sysfs attributes and replaces the NULL
with a pointer to an attribute structure if it decides to expose
cpb.

That is confusing, so make the driver set the pointer to the cpb
attribute structure upfront and replace it with NULL if the
attribute should not be exposed instead.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar

cpufreq: acpi-cpufreq: Drop acpi_data from struct acpi_cpufreq_data

2015-07-22T20:11:56+00:00

After commit 8cfcfd39000d (acpi-cpufreq: Fix an ACPI perf unregister
issue) we store both a pointer to per-CPU data of the first policy
CPU and the number of that CPU which are redundant.

Since the CPU number has to be stored anyway for the unregistration,
the pointer to the CPU's per-CPU data may be dropped and we can
access the data in question via per_cpu_ptr().

Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar

ACPI / processor: Drop an unused argument of a cleanup routine

2015-07-22T20:11:16+00:00

acpi_processor_unregister_performance() actually doesn't use its
first argument, so drop it and update the callers accordingly.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar

acpi-cpufreq: Fix an ACPI perf unregister issue

2015-07-16T21:51:26+00:00

As policy->cpu may not be same in acpi_cpufreq_cpu_init() and
acpi_cpufreq_cpu_exit(). There is a risk that we use different CPU
to un/register ACPI performance. So acpi_processor_unregister_performance()
may not be able to do the cleanup work. That causes a memory leak. And
if there will be another acpi_processor_register_performance() call,
it may also fail thanks to the internal check of pr->performace.

So add a new struct acpi_cpufreq_data field, acpi_perf_cpu, to fix
this issue.

Signed-off-by: Pan Xinhui 
Acked-by: Viresh Kumar 
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki

acpi-cpufreq: replace per_cpu with driver_data of policy

2015-07-16T21:51:05+00:00

Drivers can store their internal per-policy information in
policy->driver_data, lets use it.

we have benefits after this replacing.
1) memory saving.
2) policy is shared by several cpus, per_cpu seems not correct. using
*driver_data* is more reasonable.
3) fix a memory leak in acpi_cpufreq_cpu_exit. as policy->cpu might
change during cpu hotplug. So sometimes we cant't free *data*, use
*driver_data* to fix it.
4) fix a zero return value of get_cur_freq_on_cpu. Only per_cpu of
policy->cpu is set to *data*, if we try to get cpufreq on other cpus, we
get zero instead of correct values. Use *driver_data* to fix it.

Signed-off-by: Pan Xinhui 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

acpi-cpufreq: Replace cpumask() with topologycpumask()

2015-05-27T13:22:16+00:00

The former duplicate the functionalities of the latter but are
neither documented nor arch-independent.

Signed-off-by: Bartosz Golaszewski 
Acked-by: Viresh Kumar 
Acked-by: Rafael J. Wysocki 
Cc: Benoit Cousson 
Cc: Catalin Marinas 
Cc: Fenghua Yu 
Cc: Guenter Roeck 
Cc: Jean Delvare 
Cc: Jonathan Corbet 
Cc: Linus Torvalds 
Cc: Oleg Drokin 
Cc: Peter Zijlstra 
Cc: Russell King 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1432645896-12588-7-git-send-email-bgolaszewski@baylibre.com
Signed-off-by: Ingo Molnar

cpufreq: Use cpufreq_for_each_* macros for frequency table iteration

2014-04-29T22:06:21+00:00

The cpufreq core now supports the cpufreq_for_each_entry and
cpufreq_for_each_valid_entry macros helpers for iteration over the
cpufreq_frequency_table, so use them.

It should have no functional changes.

Signed-off-by: Stratos Karafotis 
Acked-by: Lad, Prabhakar 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki

Merge branch 'pm-cpufreq'

2014-04-08T11:28:02+00:00

* pm-cpufreq:
  cpufreq: ppc: Remove duplicate inclusion of fsl_soc.h
  cpufreq: create another field .flags in cpufreq_frequency_table
  cpufreq: use kzalloc() to allocate memory for cpufreq_frequency_table
  cpufreq: don't print value of .driver_data from core
  cpufreq: ia64: don't set .driver_data to index
  cpufreq: powernv: Select CPUFreq related Kconfig options for powernv
  cpufreq: powernv: Use cpufreq_frequency_table.driver_data to store pstate ids
  cpufreq: powernv: cpufreq driver for powernv platform
  cpufreq: at32ap: don't declare local variable as static
  cpufreq: loongson2_cpufreq: don't declare local variable as static
  cpufreq: unicore32: fix typo issue for 'clk'
  cpufreq: exynos: Disable on multiplatform build