The b.L switcher can be turned on/off at run time. It is therefore necessary to change the cpufreq driver behavior accordingly.
The driver must be unregistered/registered with the cpufreq core to reconfigure freq tables for the virtual or actual CPUs. This is accomplished via the b.L switcher notifier callback.
Signed-off-by: Nicolas Pitre nicolas.pitre@linaro.org --- drivers/cpufreq/arm_big_little.c | 54 +++++++++++++++++++++++++++++++++++++--- 1 file changed, 51 insertions(+), 3 deletions(-)
diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c index ba73f868b6..0904f0e0e6 100644 --- a/drivers/cpufreq/arm_big_little.c +++ b/drivers/cpufreq/arm_big_little.c @@ -40,9 +40,12 @@ #define MAX_CLUSTERS 2
#ifdef CONFIG_BL_SWITCHER -#define is_bL_switching_enabled() true +static bool bL_switching_enabled; +#define is_bL_switching_enabled() bL_switching_enabled +#define set_switching_enabled(x) (bL_switching_enabled = (x)) #else #define is_bL_switching_enabled() false +#define set_switching_enabled(x) do { } while (0) #endif
#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq) @@ -533,6 +536,38 @@ static struct cpufreq_driver bL_cpufreq_driver = { .attr = bL_cpufreq_attr, };
+static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb, + unsigned long action, void *_arg) +{ + pr_debug("%s: action: %ld\n", __func__, action); + + switch (action) { + case BL_NOTIFY_PRE_ENABLE: + case BL_NOTIFY_PRE_DISABLE: + cpufreq_unregister_driver(&bL_cpufreq_driver); + break; + + case BL_NOTIFY_POST_ENABLE: + set_switching_enabled(true); + cpufreq_register_driver(&bL_cpufreq_driver); + break; + + case BL_NOTIFY_POST_DISABLE: + set_switching_enabled(false); + cpufreq_register_driver(&bL_cpufreq_driver); + break; + + default: + return NOTIFY_DONE; + } + + return NOTIFY_OK; +} + +static struct notifier_block bL_switcher_notifier = { + .notifier_call = bL_cpufreq_switcher_notifier, +}; + int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops) { int ret, i; @@ -550,6 +585,9 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
arm_bL_ops = ops;
+ ret = bL_switcher_get_enabled(); + set_switching_enabled(ret); + for (i = 0; i < MAX_CLUSTERS; i++) mutex_init(&cluster_lock[i]);
@@ -559,10 +597,17 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops) __func__, ops->name, ret); arm_bL_ops = NULL; } else { - pr_info("%s: Registered platform driver: %s\n", __func__, - ops->name); + ret = bL_switcher_register_notifier(&bL_switcher_notifier); + if (ret) { + cpufreq_unregister_driver(&bL_cpufreq_driver); + arm_bL_ops = NULL; + } else { + pr_info("%s: Registered platform driver: %s\n", + __func__, ops->name); + } }
+ bL_switcher_put_enabled(); return ret; } EXPORT_SYMBOL_GPL(bL_cpufreq_register); @@ -575,7 +620,10 @@ void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops) return; }
+ bL_switcher_get_enabled(); + bL_switcher_unregister_notifier(&bL_switcher_notifier); cpufreq_unregister_driver(&bL_cpufreq_driver); + bL_switcher_put_enabled(); pr_info("%s: Un-registered platform driver: %s\n", __func__, arm_bL_ops->name); arm_bL_ops = NULL;