CPUFreq drivers today support a ->get(cpu) callback, which returns current rate of a CPU. The problem with ->get() is that it takes a cpu number as parameter and this unnecessarily makes things complex.
Firstly the core gets the cpu number by doing operation 'policy->cpu' on the policy and then many drivers need to get the policy back and so do cpufreq_cpu_get(cpu) on the passed cpu.
As cpufreq core works on policies, it would be better if we pass them 'policy' directly and drivers can use policy->cpu if that's all they need.
Hence, this patch adds in another callback, ->get_rate() which does exactly the same work as ->get(), just that we pass 'policy' as parameter instead of 'cpu'.
The plan is to migrate all drivers to this new callback and remove ->get() after that.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- Hi Rafael,
I hope you are fine with this stuff :), once you approve I will get other patches to migrate existing drivers to this interface.
drivers/cpufreq/cpufreq.c | 50 ++++++++++++++++++++++++++++++++--------------- include/linux/cpufreq.h | 1 + 2 files changed, 35 insertions(+), 16 deletions(-)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index b612411655f9..b66e169601e8 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -154,6 +154,20 @@ void disable_cpufreq(void) } static DEFINE_MUTEX(cpufreq_governor_mutex);
+/* Operations for ->get() and ->get_rate() operations */ +static inline bool driver_supports_get_rate(void) +{ + return cpufreq_driver->get || cpufreq_driver->get_rate; +} + +static inline unsigned int policy_get_rate(struct cpufreq_policy *policy) +{ + if (cpufreq_driver->get) + return cpufreq_driver->get(policy->cpu); + else + return cpufreq_driver->get_rate(policy); +} + bool have_governor_per_policy(void) { return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); @@ -596,8 +610,9 @@ static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) { ssize_t ret;
- if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) - ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); + if (cpufreq_driver && cpufreq_driver->setpolicy && + driver_supports_get_rate()) + ret = sprintf(buf, "%u\n", policy_get_rate(policy)); else ret = sprintf(buf, "%u\n", policy->cur); return ret; @@ -1032,7 +1047,7 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, return ret; drv_attr++; } - if (cpufreq_driver->get) { + if (driver_supports_get_rate()) { ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); if (ret) return ret; @@ -1313,10 +1328,10 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) write_unlock_irqrestore(&cpufreq_driver_lock, flags); }
- if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { - policy->cur = cpufreq_driver->get(policy->cpu); + if (driver_supports_get_rate() && !cpufreq_driver->setpolicy) { + policy->cur = policy_get_rate(policy); if (!policy->cur) { - pr_err("%s: ->get() failed\n", __func__); + pr_err("%s: ->get_rate() failed\n", __func__); goto err_get_freq; } } @@ -1594,14 +1609,17 @@ unsigned int cpufreq_quick_get(unsigned int cpu) struct cpufreq_policy *policy; unsigned int ret_freq = 0;
- if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) - return cpufreq_driver->get(cpu); - policy = cpufreq_cpu_get(cpu); - if (policy) { + if (!policy) + return 0; + + if (cpufreq_driver && cpufreq_driver->setpolicy && + driver_supports_get_rate()) + ret_freq = policy_get_rate(policy); + else ret_freq = policy->cur; - cpufreq_cpu_put(policy); - } + + cpufreq_cpu_put(policy);
return ret_freq; } @@ -1631,10 +1649,10 @@ static unsigned int __cpufreq_get(struct cpufreq_policy *policy) { unsigned int ret_freq = 0;
- if (!cpufreq_driver->get) + if (!driver_supports_get_rate()) return ret_freq;
- ret_freq = cpufreq_driver->get(policy->cpu); + ret_freq = policy_get_rate(policy);
/* Updating inactive policies is invalid, so avoid doing that. */ if (unlikely(policy_is_inactive(policy))) @@ -2345,8 +2363,8 @@ int cpufreq_update_policy(unsigned int cpu) * BIOS might change freq behind our back * -> ask driver for current freq and notify governors about a change */ - if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { - new_policy.cur = cpufreq_driver->get(cpu); + if (driver_supports_get_rate() && !cpufreq_driver->setpolicy) { + new_policy.cur = policy_get_rate(policy); if (WARN_ON(!new_policy.cur)) { ret = -EIO; goto unlock; diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 29ad97c34fd5..a82049683016 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -263,6 +263,7 @@ struct cpufreq_driver {
/* should be defined, if possible */ unsigned int (*get)(unsigned int cpu); + unsigned int (*get_rate)(struct cpufreq_policy *policy);
/* optional */ int (*bios_limit)(int cpu, unsigned int *limit);