linux-toradex.git/include/linux/cpufreq.h, branch v2.6.36-rc5

[CPUFREQ] unexport (un)lock_policy_rwsem* functions

2010-08-03T17:47:04+00:00

lock_policy_rwsem_* and unlock_policy_rwsem_* functions are scheduled
to be unexported when 2.6.33. Now there are no other callers of them
out of cpufreq.c, unexport them and make them static.

Signed-off-by: WANG Cong 
Cc: Venkatesh Pallipadi 
Signed-off-by: Dave Jones

cpufreq: Unify sysfs attribute definition macros

2010-04-09T21:07:56+00:00

Multiple modules used to define those which are with identical
functionality and were needlessly replicated among the different cpufreq
drivers. Push them into the header and remove duplication.

Signed-off-by: Borislav Petkov 
LKML-Reference: <1270065406-1814-7-git-send-email-bp@amd64.org>
Reviewed-by: Thomas Renninger 
Signed-off-by: H. Peter Anvin

[ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface

2009-11-24T18:33:34+00:00

This interface is mainly intended (and implemented) for ACPI _PPC BIOS
frequency limitations, but other cpufreq drivers can also use it for
similar use-cases.

Why is this needed:

Currently it's not obvious why cpufreq got limited.
People see cpufreq/scaling_max_freq reduced, but this could have
happened by:
  - any userspace prog writing to scaling_max_freq
  - thermal limitations
  - hardware (_PPC in ACPI case) limitiations

Therefore export bios_limit (in kHz) to:
  - Point the user that it's the BIOS (broken or intended) which limits
    frequency
  - Export it as a sysfs interface for userspace progs.
    While this was a rarely used feature on laptops, there will appear
    more and more server implemenations providing "Green IT" features like
    allowing the service processor to limit the frequency. People want
    to know about HW/BIOS frequency limitations.

All ACPI P-state driven cpufreq drivers are covered with this patch:
  - powernow-k8
  - powernow-k7
  - acpi-cpufreq

Tested with a patched DSDT which limits the first two cores (_PPC returns 1)
via _PPC, exposed by bios_limit:
# echo 2200000 >cpu2/cpufreq/scaling_max_freq
# cat cpu*/cpufreq/scaling_max_freq
2600000
2600000
2200000
2200000
# #scaling_max_freq shows general user/thermal/BIOS limitations

# cat cpu*/cpufreq/bios_limit
2600000
2600000
2800000
2800000
# #bios_limit only shows the HW/BIOS limitation

CC: Pallipadi Venkatesh 
CC: Len Brown 
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.net

Signed-off-by: Thomas Renninger 
Signed-off-by: Dave Jones

cpufreq: add cpufreq_get() stub for CONFIG_CPU_FREQ=n

2009-10-29T14:39:24+00:00

When CONFIG_CPU_FREQ is disabled, cpufreq_get() needs a stub.  Used by kvm
(although it looks like a bit of the kvm code could be omitted when
CONFIG_CPU_FREQ is disabled).

arch/x86/built-in.o: In function `kvm_arch_init':
(.text+0x10de7): undefined reference to `cpufreq_get'

(Needed in linux-next's KVM tree, but it's correct in 2.6.32).

Signed-off-by: Randy Dunlap 
Tested-by: Eric Paris 
Cc: Jiri Slaby 
Cc: Avi Kivity 
Cc: Marcelo Tosatti 
Cc: Dave Jones 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[CPUFREQ] Introduce global, not per core: /sys/devices/system/cpu/cpufreq

2009-09-01T16:45:14+00:00

Currently everything in the cpufreq layer is per core based.
This does not reflect reality, for example ondemand on conservative
governors have global sysfs variables.

Introduce a global cpufreq directory and add the kobject to the governor
struct, so that governors can easily access it.
The directory is initialized in the cpufreq_core_init initcall and thus will
always be created if cpufreq is compiled in, even if no cpufreq driver is
active later.

Signed-off-by: Thomas Renninger 
Signed-off-by: Dave Jones

Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."

2009-03-09T19:07:33+00:00

This reverts commit e088e4c9cdb618675874becb91b2fd581ee707e6.

Removing the sysfs interface for p4-clockmod was flagged as a
regression in bug 12826.

Course of action:
 - Find out the remaining causes of overheating, and fix them
   if possible. ACPI should be doing the right thing automatically.
   If it isn't, we need to fix that.
 - mark p4-clockmod ui as deprecated
 - try again with the removal in six months.

It's not really feasible to printk about the deprecation, because
it needs to happen at all the sysfs entry points, which means adding
a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch.

Signed-off-by: Dave Jones

cpumask: convert struct cpufreq_policy to cpumask_var_t

2009-01-06T08:05:31+00:00

Impact: use new cpumask API to reduce memory usage

This is part of an effort to reduce structure sizes for machines
configured with large NR_CPUS.  cpumask_t gets replaced by
cpumask_var_t, which is either struct cpumask[1] (small NR_CPUS) or
struct cpumask * (large NR_CPUS).

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Acked-by: Dave Jones 
Signed-off-by: Ingo Molnar

[CPUFREQ] Disable sysfs ui for p4-clockmod.

2008-12-05T20:20:10+00:00

p4-clockmod has a long history of abuse.   It pretends to be a CPU
frequency scaling driver, even though it doesn't actually change
the CPU frequency, but instead just modulates the frequency with
wait-states.
The biggest misconception is that when running at the lower 'frequency'
p4-clockmod is saving power.  This isn't the case, as workloads running
slower take longer to complete, preventing the CPU from entering deep C states.

However p4-clockmod does have a purpose.  It can prevent overheating.
Having it hooked up to the cpufreq interfaces is the wrong way to achieve
cooling however. It should instead be hooked up to ACPI.

This diff introduces a means for a cpufreq driver to register with the
cpufreq core, but not present a sysfs interface.

Signed-off-by: Matthew Garrett 
Signed-off-by: Dave Jones

[CPUFREQ][1/6] cpufreq: Add cpu number parameter to __cpufreq_driver_getavg()

2008-10-09T17:52:43+00:00

Add a cpu parameter to __cpufreq_driver_getavg(). This is needed for software
cpufreq coordination where policy->cpu may not be same as the CPU on which we
want to getavg frequency.

A follow-on patch will use this parameter to getavg freq from all cpus
in policy->cpus.

Change since last patch. Fix the offline/online and suspend/resume
oops reported by Youquan Song 

Signed-off-by: Venkatesh Pallipadi 
Signed-off-by: Dave Jones

cpufreq acpi: only call _PPC after cpufreq ACPI init funcs got called already

2008-07-30T16:41:43+00:00

Ingo Molnar provided a fix to not call _PPC at processor driver
initialization time in "[PATCH] ACPI: fix cpufreq regression" (git
commit e4233dec749a3519069d9390561b5636a75c7579)

But it can still happen that _PPC is called at processor driver
initialization time.

This patch should make sure that this is not possible anymore.

Signed-off-by: Thomas Renninger 
Cc: Andi Kleen 
Cc: Len Brown 
Cc: Dave Jones 
Cc: Ingo Molnar 
Cc: Venkatesh Pallipadi 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds