diff options
| author | Dirk Brandewie <dirk.j.brandewie@intel.com> | 2014-03-19 08:45:53 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-03-20 03:50:12 +0100 |
| commit | 367dc4aa932bfb33a3189064d33f7890a8ec1ca8 (patch) | |
| tree | fde9bd6004ff7852da144a373dd1c0536521efef | |
| parent | bda9f552f9826313ef8a477fc8e4891de9ae5e73 (diff) | |
cpufreq: Add stop CPU callback to cpufreq_driver interface
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>
| -rw-r--r-- | Documentation/cpu-freq/cpu-drivers.txt | 8 | ||||
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 2 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 1 |
3 files changed, 10 insertions, 1 deletions
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt index 8b1a4451422e..48da5fdcb9f1 100644 --- a/Documentation/cpu-freq/cpu-drivers.txt +++ b/Documentation/cpu-freq/cpu-drivers.txt @@ -61,7 +61,13 @@ target_index - See below on the differences. 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 which is called with interrupts disabled diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 3c56c4759aa1..3aa7a7a226b3 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -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", __func__, new_cpu, cpu); } + } else if (cpufreq_driver->stop_cpu && cpufreq_driver->setpolicy) { + cpufreq_driver->stop_cpu(policy); } return 0; diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 70929bcf1a9d..2d2e62c8666a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -227,6 +227,7 @@ struct cpufreq_driver { int (*bios_limit) (int cpu, unsigned int *limit); int (*exit) (struct cpufreq_policy *policy); + void (*stop_cpu) (struct cpufreq_policy *policy); int (*suspend) (struct cpufreq_policy *policy); int (*resume) (struct cpufreq_policy *policy); struct freq_attr **attr; |