From 9558fae8ce97b3b320b387dd7c88309df2c36d4d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 25 Mar 2024 18:04:24 +0100 Subject: cpufreq: intel_pstate: Read global.no_turbo under READ_ONCE() Because global.no_turbo is generally not read under intel_pstate_driver_lock make store_no_turbo() use WRITE_ONCE() for updating it (this is the only place at which it is updated except for the initialization) and make the majority of places reading it use READ_ONCE(). Also remove redundant global.turbo_disabled checks from places that depend on the 'true' value of global.no_turbo because it can only be 'true' if global.turbo_disabled is also 'true'. Signed-off-by: Rafael J. Wysocki Acked-by: Srinivas Pandruvada --- drivers/cpufreq/intel_pstate.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/cpufreq') diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 357993ae1454..3a707e34acd8 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1296,7 +1296,7 @@ static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b, goto unlock_driver; } - global.no_turbo = no_turbo; + WRITE_ONCE(global.no_turbo, no_turbo); mutex_lock(&intel_pstate_limits_lock); @@ -1748,7 +1748,7 @@ static u64 atom_get_val(struct cpudata *cpudata, int pstate) u32 vid; val = (u64)pstate << 8; - if (global.no_turbo && !global.turbo_disabled) + if (READ_ONCE(global.no_turbo) && !global.turbo_disabled) val |= (u64)1 << 32; vid_fp = cpudata->vid.min + mul_fp( @@ -1913,7 +1913,7 @@ static u64 core_get_val(struct cpudata *cpudata, int pstate) u64 val; val = (u64)pstate << 8; - if (global.no_turbo && !global.turbo_disabled) + if (READ_ONCE(global.no_turbo) && !global.turbo_disabled) val |= (u64)1 << 32; return val; @@ -2211,7 +2211,7 @@ static inline int32_t get_target_pstate(struct cpudata *cpu) sample->busy_scaled = busy_frac * 100; - target = global.no_turbo || global.turbo_disabled ? + target = READ_ONCE(global.no_turbo) ? cpu->pstate.max_pstate : cpu->pstate.turbo_pstate; target += target >> 2; target = mul_fp(target, busy_frac); @@ -2473,7 +2473,7 @@ static void intel_pstate_clear_update_util_hook(unsigned int cpu) static int intel_pstate_get_max_freq(struct cpudata *cpu) { - return global.turbo_disabled || global.no_turbo ? + return READ_ONCE(global.no_turbo) ? cpu->pstate.max_freq : cpu->pstate.turbo_freq; } @@ -2610,7 +2610,7 @@ static void intel_pstate_verify_cpu_policy(struct cpudata *cpu, if (hwp_active) { intel_pstate_get_hwp_cap(cpu); - max_freq = global.no_turbo || global.turbo_disabled ? + max_freq = READ_ONCE(global.no_turbo) ? cpu->pstate.max_freq : cpu->pstate.turbo_freq; } else { max_freq = intel_pstate_get_max_freq(cpu); -- cgit v1.2.3