iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

cpufreq: Add stop CPU callback to cpufreq_driver interface

Browse Source 
This callback allows the driver to do clean up before the CPU is
completely down and its state cannot be modified.  This is used
by the intel_pstate driver to reduce the requested P state prior to
the core going away.  This is required because the requested P state
of the offline core is used to select the package P state. This
effectively sets the floor package P state to the requested P state on
the offline core.

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
[rjw: Minor modifications]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Dirk Brandewie 2014-03-19 08:45:53 -07:00 committed by Rafael J. Wysocki
parent bda9f552f9
commit 367dc4aa93
3 changed files with 10 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
Documentation/cpu-freq/cpu-drivers.txt
View File

@ -61,7 +61,13 @@ target_index - See below on the differences.
And optionally And optionally
cpufreq_driver.exit - A pointer to a per-CPU cleanup function. cpufreq_driver.exit - A pointer to a per-CPU cleanup
function called during CPU_POST_DEAD
phase of cpu hotplug process.
cpufreq_driver.stop_cpu - A pointer to a per-CPU stop function
called during CPU_DOWN_PREPARE phase of
cpu hotplug process.
cpufreq_driver.resume - A pointer to a per-CPU resume function cpufreq_driver.resume - A pointer to a per-CPU resume function
which is called with interrupts disabled which is called with interrupts disabled

2
drivers/cpufreq/cpufreq.c
View File

@ -1337,6 +1337,8 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
__func__, new_cpu, cpu); __func__, new_cpu, cpu);
} }
} else if (cpufreq_driver->stop_cpu && cpufreq_driver->setpolicy) {
cpufreq_driver->stop_cpu(policy);
} }
return 0; return 0;

1
include/linux/cpufreq.h
View File

@ -227,6 +227,7 @@ struct cpufreq_driver {
int (*bios_limit) (int cpu, unsigned int *limit); int (*bios_limit) (int cpu, unsigned int *limit);
int (*exit) (struct cpufreq_policy *policy); int (*exit) (struct cpufreq_policy *policy);
void (*stop_cpu) (struct cpufreq_policy *policy);
int (*suspend) (struct cpufreq_policy *policy); int (*suspend) (struct cpufreq_policy *policy);
int (*resume) (struct cpufreq_policy *policy); int (*resume) (struct cpufreq_policy *policy);
struct freq_attr **attr; struct freq_attr **attr;