6.6-stable review patch. If anyone has any objections, please let me know.
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From: Rafael J. Wysocki rafael.j.wysocki@intel.com
[ Upstream commit 9558fae8ce97b3b320b387dd7c88309df2c36d4d ]
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 rafael.j.wysocki@intel.com Acked-by: Srinivas Pandruvada srinivas.pandruvada@linux.intel.com Stable-dep-of: 350cbb5d2f67 ("cpufreq: intel_pstate: Check turbo_is_disabled() in store_no_turbo()") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/cpufreq/intel_pstate.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 8bac7afb13a3d..05aae7e6da157 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1297,7 +1297,7 @@ 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);
@@ -1766,7 +1766,7 @@ 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( @@ -1931,7 +1931,7 @@ 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; @@ -2229,7 +2229,7 @@ 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); @@ -2490,7 +2490,7 @@ 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; }
@@ -2627,7 +2627,7 @@ 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);