diff options
| author | Rohit Gupta <rohgup@codeaurora.org> | 2014-11-14 17:53:15 -0800 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-23 20:02:59 -0700 |
| commit | db44d1e057ce4c3396668fd0e55cba71729ce71e (patch) | |
| tree | 9f4374b51f0294f152ca91a16df2f48ac17e8729 | |
| parent | db35fc6d65c4e53ea31b7c599c5072367b450af0 (diff) | |
cpufreq: Add a notifer chain that governors can use to report information
Some modules can benefit from getting additional information cpufreq
governors use to make frequency switch decisions.
This change lays down a basic framework that the governors can use
to report additional information (Eg: CPU's load) information to
the clients that subscribe to cpufreq govinfo notifier chain.
Change-Id: I511b4bdb7d12394a31ce5352ae47553861e49303
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
[imaund@codeaurora.org: resolved context conflicts]
Signed-off-by: Ian Maund <imaund@codeaurora.org>
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 21 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 14 |
2 files changed, 34 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index e49512718325..f897a7dec97d 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -127,6 +127,7 @@ static void handle_update(struct work_struct *work); */ static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); static struct srcu_notifier_head cpufreq_transition_notifier_list; +struct atomic_notifier_head cpufreq_govinfo_notifier_list; static bool init_cpufreq_transition_notifier_list_called; static int __init init_cpufreq_transition_notifier_list(void) @@ -137,6 +138,15 @@ static int __init init_cpufreq_transition_notifier_list(void) } pure_initcall(init_cpufreq_transition_notifier_list); +static bool init_cpufreq_govinfo_notifier_list_called; +static int __init init_cpufreq_govinfo_notifier_list(void) +{ + ATOMIC_INIT_NOTIFIER_HEAD(&cpufreq_govinfo_notifier_list); + init_cpufreq_govinfo_notifier_list_called = true; + return 0; +} +pure_initcall(init_cpufreq_govinfo_notifier_list); + static int off __read_mostly; static int cpufreq_disabled(void) { @@ -1703,7 +1713,8 @@ int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) if (cpufreq_disabled()) return -EINVAL; - WARN_ON(!init_cpufreq_transition_notifier_list_called); + WARN_ON(!init_cpufreq_transition_notifier_list_called || + !init_cpufreq_govinfo_notifier_list_called); switch (list) { case CPUFREQ_TRANSITION_NOTIFIER: @@ -1714,6 +1725,10 @@ int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) ret = blocking_notifier_chain_register( &cpufreq_policy_notifier_list, nb); break; + case CPUFREQ_GOVINFO_NOTIFIER: + ret = atomic_notifier_chain_register( + &cpufreq_govinfo_notifier_list, nb); + break; default: ret = -EINVAL; } @@ -1748,6 +1763,10 @@ int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) ret = blocking_notifier_chain_unregister( &cpufreq_policy_notifier_list, nb); break; + case CPUFREQ_GOVINFO_NOTIFIER: + ret = atomic_notifier_chain_unregister( + &cpufreq_govinfo_notifier_list, nb); + break; default: ret = -EINVAL; } diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 3ac01621cd1f..af746a212e88 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -361,6 +361,7 @@ static inline void cpufreq_resume(void) {} #define CPUFREQ_TRANSITION_NOTIFIER (0) #define CPUFREQ_POLICY_NOTIFIER (1) +#define CPUFREQ_GOVINFO_NOTIFIER (2) /* Transition notifiers */ #define CPUFREQ_PRECHANGE (0) @@ -373,6 +374,9 @@ static inline void cpufreq_resume(void) {} #define CPUFREQ_CREATE_POLICY (3) #define CPUFREQ_REMOVE_POLICY (4) +/* Govinfo Notifiers */ +#define CPUFREQ_LOAD_CHANGE (0) + #ifdef CONFIG_CPU_FREQ int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list); int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list); @@ -381,6 +385,16 @@ void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs); void cpufreq_freq_transition_end(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs, int transition_failed); +/* + * Governor specific info that can be passed to modules that subscribe + * to CPUFREQ_GOVINFO_NOTIFIER + */ +struct cpufreq_govinfo { + unsigned int cpu; + unsigned int load; + unsigned int sampling_rate_us; +}; +extern struct atomic_notifier_head cpufreq_govinfo_notifier_list; #else /* CONFIG_CPU_FREQ */ static inline int cpufreq_register_notifier(struct notifier_block *nb, |