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cpufreq: intel_pstate: Simplify intel_pstate_update_perf_limits() 

Because pstate.max_freq is always equal to the product of
pstate.max_pstate and pstate.scaling and, analogously,
pstate.turbo_freq is always equal to the product of
pstate.turbo_pstate and pstate.scaling, the result of the
max_policy_perf computation in intel_pstate_update_perf_limits() is
always equal to the quotient of policy_max and pstate.scaling,
regardless of whether or not turbo is disabled.  Analogously, the
result of min_policy_perf in intel_pstate_update_perf_limits() is
always equal to the quotient of policy_min and pstate.scaling.

Accordingly, intel_pstate_update_perf_limits() need not check
whether or not turbo is enabled at all and in order to compute
max_policy_perf and min_policy_perf it can always divide policy_max
and policy_min, respectively, by pstate.scaling.  Make it do so.

While at it, move the definition and initialization of the
turbo_max local variable to the code branch using it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
This commit is contained in:
Rafael J. Wysocki 2021-04-07 16:21:55 +02:00
parent 60943bbdb4
commit b989bc0f3c
1 changed files with 6 additions and 16 deletions
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22
drivers/cpufreq/intel_pstate.c
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@ -2195,9 +2195,8 @@ static void intel_pstate_update_perf_limits(struct cpudata *cpu,
unsigned int policy_min,
unsigned int policy_max)
{
int scaling = cpu->pstate.scaling;
int32_t max_policy_perf, min_policy_perf;
int max_state, turbo_max;
int max_freq;
/*
* HWP needs some special consideration, because HWP_REQUEST uses
@ -2206,33 +2205,24 @@ static void intel_pstate_update_perf_limits(struct cpudata *cpu,
if (hwp_active)
intel_pstate_get_hwp_cap(cpu);
if (global.no_turbo || global.turbo_disabled) {
max_state = cpu->pstate.max_pstate;
max_freq = cpu->pstate.max_freq;
} else {
max_state = cpu->pstate.turbo_pstate;
max_freq = cpu->pstate.turbo_freq;
}
turbo_max = cpu->pstate.turbo_pstate;
max_policy_perf = max_state * policy_max / max_freq;
max_policy_perf = policy_max / scaling;
if (policy_max == policy_min) {
min_policy_perf = max_policy_perf;
} else {
min_policy_perf = max_state * policy_min / max_freq;
min_policy_perf = policy_min / scaling;
min_policy_perf = clamp_t(int32_t, min_policy_perf,
0, max_policy_perf);
}
pr_debug("cpu:%d max_state %d min_policy_perf:%d max_policy_perf:%d\n",
cpu->cpu, max_state, min_policy_perf, max_policy_perf);
pr_debug("cpu:%d min_policy_perf:%d max_policy_perf:%d\n",
cpu->cpu, min_policy_perf, max_policy_perf);
/* Normalize user input to [min_perf, max_perf] */
if (per_cpu_limits) {
cpu->min_perf_ratio = min_policy_perf;
cpu->max_perf_ratio = max_policy_perf;
} else {
int turbo_max = cpu->pstate.turbo_pstate;
int32_t global_min, global_max;
/* Global limits are in percent of the maximum turbo P-state. */