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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
cpufreq/amd-pstate: Cache the max frequency in cpudata
The value of maximum frequency is fixed and never changes. Doing
calculations every time based off of perf is unnecessary.
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20260326193620.649441-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
+11
-18
+9
-18
drivers/cpufreq/amd-pstate.c
+9
-18
drivers/cpufreq/amd-pstate.c
···
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826
static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
827
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{
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struct amd_cpudata *cpudata = policy->driver_data;
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-
union perf_cached perf = READ_ONCE(cpudata->perf);
830
-
u32 nominal_freq, max_freq;
829
+
u32 nominal_freq;
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int ret = 0;
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nominal_freq = READ_ONCE(cpudata->nominal_freq);
834
-
max_freq = perf_to_freq(perf, cpudata->nominal_freq, perf.highest_perf);
835
833
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834
if (on)
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-
policy->cpuinfo.max_freq = max_freq;
835
+
policy->cpuinfo.max_freq = cpudata->max_freq;
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else if (policy->cpuinfo.max_freq > nominal_freq)
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policy->cpuinfo.max_freq = nominal_freq;
840
838
···
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WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
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1024
+
/* max_freq is calculated according to (nominal_freq * highest_perf)/nominal_perf */
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max_freq = perf_to_freq(perf, nominal_freq, perf.highest_perf);
1026
+
WRITE_ONCE(cpudata->max_freq, max_freq);
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+
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lowest_nonlinear_freq = perf_to_freq(perf, nominal_freq, perf.lowest_nonlinear_perf);
1024
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WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
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/**
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* Below values need to be initialized correctly, otherwise driver will fail to load
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-
* max_freq is calculated according to (nominal_freq * highest_perf)/nominal_perf
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* lowest_nonlinear_freq is a value between [min_freq, nominal_freq]
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* Check _CPC in ACPI table objects if any values are incorrect
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*/
···
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policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
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cpudata->nominal_freq,
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perf.lowest_perf);
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-
policy->cpuinfo.max_freq = policy->max = perf_to_freq(perf,
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cpudata->nominal_freq,
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perf.highest_perf);
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+
policy->cpuinfo.max_freq = policy->max = cpudata->max_freq;
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policy->driver_data = cpudata;
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ret = amd_pstate_cppc_enable(policy);
···
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static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy,
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char *buf)
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{
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-
struct amd_cpudata *cpudata;
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union perf_cached perf;
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+
struct amd_cpudata *cpudata = policy->driver_data;
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-
cpudata = policy->driver_data;
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perf = READ_ONCE(cpudata->perf);
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-
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-
return sysfs_emit(buf, "%u\n",
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-
perf_to_freq(perf, cpudata->nominal_freq, perf.highest_perf));
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+
return sysfs_emit(buf, "%u\n", cpudata->max_freq);
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}
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static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy,
···
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policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
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cpudata->nominal_freq,
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perf.lowest_perf);
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-
policy->cpuinfo.max_freq = policy->max = perf_to_freq(perf,
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cpudata->nominal_freq,
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-
perf.highest_perf);
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+
policy->cpuinfo.max_freq = policy->max = cpudata->max_freq;
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policy->driver_data = cpudata;
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ret = amd_pstate_cppc_enable(policy);
+2
drivers/cpufreq/amd-pstate.h
+2
drivers/cpufreq/amd-pstate.h
···
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* @min_limit_freq: Cached value of policy->min (in khz)
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* @max_limit_freq: Cached value of policy->max (in khz)
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* @nominal_freq: the frequency (in khz) that mapped to nominal_perf
76
+
* @max_freq: in ideal conditions the maximum frequency (in khz) possible frequency
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* @lowest_nonlinear_freq: the frequency (in khz) that mapped to lowest_nonlinear_perf
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* @floor_freq: Cached value of the user requested floor_freq
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* @cur: Difference of Aperf/Mperf/tsc count between last and current sample
···
104
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u32 min_limit_freq;
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u32 max_limit_freq;
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u32 nominal_freq;
106
+
u32 max_freq;
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u32 lowest_nonlinear_freq;
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u32 floor_freq;
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