From 6fec833b9d70c54ceacbf7d07665215fbd0cddef Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 28 Mar 2025 21:42:48 +0100 Subject: cpufreq: Add and use cpufreq policy locking guards Introduce "read" and "write" locking guards for cpufreq policies and use them where applicable in the cpufreq core. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Reviewed-by: Mario Limonciello Acked-by: Sudeep Holla Tested-by: Sudeep Holla Link: https://patch.msgid.link/8518682.T7Z3S40VBb@rjwysocki.net --- include/linux/cpufreq.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 400fee6427a5..cb972d2aa8df 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -170,6 +170,12 @@ struct cpufreq_policy { struct notifier_block nb_max; }; +DEFINE_GUARD(cpufreq_policy_write, struct cpufreq_policy *, + down_write(&_T->rwsem), up_write(&_T->rwsem)) + +DEFINE_GUARD(cpufreq_policy_read, struct cpufreq_policy *, + down_read(&_T->rwsem), up_read(&_T->rwsem)) + /* * Used for passing new cpufreq policy data to the cpufreq driver's ->verify() * callback for sanitization. That callback is only expected to modify the min -- cgit v1.3 From c7282dce257480f0f22ed3db69cfb400a18709f4 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 28 Mar 2025 21:45:38 +0100 Subject: cpufreq: Drop cpufreq_cpu_acquire() and cpufreq_cpu_release() Since cpufreq_cpu_acquire() and cpufreq_cpu_release() have no more users in the tree, remove them. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Reviewed-by: Mario Limonciello Acked-by: Sudeep Holla Tested-by: Sudeep Holla Link: https://patch.msgid.link/3880470.kQq0lBPeGt@rjwysocki.net --- drivers/cpufreq/cpufreq.c | 45 --------------------------------------------- include/linux/cpufreq.h | 2 -- 2 files changed, 47 deletions(-) (limited to 'include/linux') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 40244ff620b6..2ed873777fb5 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -255,51 +255,6 @@ void cpufreq_cpu_put(struct cpufreq_policy *policy) } EXPORT_SYMBOL_GPL(cpufreq_cpu_put); -/** - * cpufreq_cpu_release - Unlock a policy and decrement its usage counter. - * @policy: cpufreq policy returned by cpufreq_cpu_acquire(). - */ -void cpufreq_cpu_release(struct cpufreq_policy *policy) -{ - if (WARN_ON(!policy)) - return; - - lockdep_assert_held(&policy->rwsem); - - up_write(&policy->rwsem); - - cpufreq_cpu_put(policy); -} - -/** - * cpufreq_cpu_acquire - Find policy for a CPU, mark it as busy and lock it. - * @cpu: CPU to find the policy for. - * - * Call cpufreq_cpu_get() to get a reference on the cpufreq policy for @cpu and - * if the policy returned by it is not NULL, acquire its rwsem for writing. - * Return the policy if it is active or release it and return NULL otherwise. - * - * The policy returned by this function has to be released with the help of - * cpufreq_cpu_release() in order to release its rwsem and balance its usage - * counter properly. - */ -struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu) -{ - struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); - - if (!policy) - return NULL; - - down_write(&policy->rwsem); - - if (policy_is_inactive(policy)) { - cpufreq_cpu_release(policy); - return NULL; - } - - return policy; -} - /********************************************************************* * EXTERNALLY AFFECTING FREQUENCY CHANGES * *********************************************************************/ diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index cb972d2aa8df..a33a094ef755 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -241,8 +241,6 @@ void disable_cpufreq(void); u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy); -struct cpufreq_policy *cpufreq_cpu_acquire(unsigned int cpu); -void cpufreq_cpu_release(struct cpufreq_policy *policy); int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu); void refresh_frequency_limits(struct cpufreq_policy *policy); void cpufreq_update_policy(unsigned int cpu); -- cgit v1.3 From eaff6b62d3439ca6ee00dba4f77673a8c37dac20 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 28 Mar 2025 21:48:54 +0100 Subject: cpufreq: Pass policy pointer to ->update_limits() Since cpufreq_update_limits() obtains a cpufreq policy pointer for the given CPU and reference counts the corresponding policy object, it may as well pass the policy pointer to the cpufreq driver's ->update_limits() callback which allows that callback to avoid invoking cpufreq_cpu_get() for the same CPU. Accordingly, redefine ->update_limits() to take a policy pointer instead of a CPU number and update both drivers implementing it, intel_pstate and amd-pstate, as needed. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Reviewed-by: Mario Limonciello Acked-by: Srinivas Pandruvada Acked-by: Sudeep Holla Tested-by: Sudeep Holla Link: https://patch.msgid.link/8560367.NyiUUSuA9g@rjwysocki.net --- drivers/cpufreq/amd-pstate.c | 7 ++----- drivers/cpufreq/cpufreq.c | 2 +- drivers/cpufreq/intel_pstate.c | 29 ++++++++++++++++++----------- include/linux/cpufreq.h | 2 +- 4 files changed, 22 insertions(+), 18 deletions(-) (limited to 'include/linux') diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 6789eed1bb5b..b9d59c7425f5 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -821,19 +821,16 @@ static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata) schedule_work(&sched_prefcore_work); } -static void amd_pstate_update_limits(unsigned int cpu) +static void amd_pstate_update_limits(struct cpufreq_policy *policy) { - struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu); struct amd_cpudata *cpudata; u32 prev_high = 0, cur_high = 0; bool highest_perf_changed = false; + unsigned int cpu = policy->cpu; if (!amd_pstate_prefcore) return; - if (!policy) - return; - if (amd_get_highest_perf(cpu, &cur_high)) return; diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index c885e0ec174f..2b91ba503b32 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2769,7 +2769,7 @@ void cpufreq_update_limits(unsigned int cpu) return; if (cpufreq_driver->update_limits) - cpufreq_driver->update_limits(cpu); + cpufreq_driver->update_limits(policy); else cpufreq_policy_refresh(policy); } diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 108e4c6a371e..f5ca04b98b92 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1353,14 +1353,9 @@ static void intel_pstate_update_policies(void) cpufreq_update_policy(cpu); } -static bool intel_pstate_update_max_freq(struct cpudata *cpudata) +static void __intel_pstate_update_max_freq(struct cpufreq_policy *policy, + struct cpudata *cpudata) { - struct cpufreq_policy *policy __free(put_cpufreq_policy); - - policy = cpufreq_cpu_get(cpudata->cpu); - if (!policy) - return false; - guard(cpufreq_policy_write)(policy); if (hwp_active) @@ -1370,16 +1365,28 @@ static bool intel_pstate_update_max_freq(struct cpudata *cpudata) cpudata->pstate.max_freq : cpudata->pstate.turbo_freq; refresh_frequency_limits(policy); +} + +static bool intel_pstate_update_max_freq(struct cpudata *cpudata) +{ + struct cpufreq_policy *policy __free(put_cpufreq_policy); + + policy = cpufreq_cpu_get(cpudata->cpu); + if (!policy) + return false; + + __intel_pstate_update_max_freq(policy, cpudata); return true; } -static void intel_pstate_update_limits(unsigned int cpu) +static void intel_pstate_update_limits(struct cpufreq_policy *policy) { - struct cpudata *cpudata = all_cpu_data[cpu]; + struct cpudata *cpudata = all_cpu_data[policy->cpu]; - if (intel_pstate_update_max_freq(cpudata)) - hybrid_update_capacity(cpudata); + __intel_pstate_update_max_freq(policy, cpudata); + + hybrid_update_capacity(cpudata); } static void intel_pstate_update_limits_for_all(void) diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index a33a094ef755..f3cf2adea18f 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -399,7 +399,7 @@ struct cpufreq_driver { unsigned int (*get)(unsigned int cpu); /* Called to update policy limits on firmware notifications. */ - void (*update_limits)(unsigned int cpu); + void (*update_limits)(struct cpufreq_policy *policy); /* optional */ int (*bios_limit)(int cpu, unsigned int *limit); -- cgit v1.3