Messages in this thread Patch in this message | | | From | dirk.brandewie@gmail ... | Subject | [PATCH v2 1/2] cpufreq: Add exit_prepare callback to cpufreq_driver interface | Date | Fri, 14 Mar 2014 14:03:56 -0700 |
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From: Dirk Brandewie <dirk.j.brandewie@intel.com>
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> --- Documentation/cpu-freq/cpu-drivers.txt | 8 +++++++- drivers/cpufreq/cpufreq.c | 3 +++ include/linux/cpufreq.h | 1 + 3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/Documentation/cpu-freq/cpu-drivers.txt b/Documentation/cpu-freq/cpu-drivers.txt index 8b1a445..79def80 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 - 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 cf485d9..0d430d7 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1338,6 +1338,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev, } } + if (cpufreq_driver->stop) + cpufreq_driver->stop(policy); + return 0; } diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 4d89e0e..ff8db19 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -224,6 +224,7 @@ struct cpufreq_driver { int (*bios_limit) (int cpu, unsigned int *limit); int (*exit) (struct cpufreq_policy *policy); + int (*stop) (struct cpufreq_policy *policy); int (*suspend) (struct cpufreq_policy *policy); int (*resume) (struct cpufreq_policy *policy); struct freq_attr **attr; -- 1.8.3.1
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