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| author | Chen Yu <yu.c.chen@intel.com> | 2021-01-12 13:21:27 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-01-12 19:44:49 +0100 |
| commit | 6f67e060083a84a4cc364eab6ae40c717165fb0c (patch) | |
| tree | 031978b05159489fd6609d7d1ab6673b593b6289 /drivers | |
| parent | 597ffbc8d085870e071807b514a6ed45809f81a5 (diff) | |
| download | lwn-6f67e060083a84a4cc364eab6ae40c717165fb0c.tar.gz lwn-6f67e060083a84a4cc364eab6ae40c717165fb0c.zip | |
cpufreq: intel_pstate: Get per-CPU max freq via MSR_HWP_CAPABILITIES if available
Currently, when turbo is disabled (either by BIOS or by the user),
the intel_pstate driver reads the max non-turbo frequency from the
package-wide MSR_PLATFORM_INFO(0xce) register.
However, on asymmetric platforms it is possible in theory that small
and big core with HWP enabled might have different max non-turbo CPU
frequency, because MSR_HWP_CAPABILITIES is per-CPU scope according
to Intel Software Developer Manual.
The turbo max freq is already per-CPU in current code, so make
similar change to the max non-turbo frequency as well.
Reported-by: Wendy Wang <wendy.wang@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
[ rjw: Subject and changelog edits ]
Cc: 4.18+ <stable@vger.kernel.org> # 4.18+: a45ee4d4e13b: cpufreq: intel_pstate: Change intel_pstate_get_hwp_max() argument
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 86873f4c6a72..6f2ff2775664 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1714,11 +1714,9 @@ static void intel_pstate_max_within_limits(struct cpudata *cpu) static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) { cpu->pstate.min_pstate = pstate_funcs.get_min(); - cpu->pstate.max_pstate = pstate_funcs.get_max(); cpu->pstate.max_pstate_physical = pstate_funcs.get_max_physical(); cpu->pstate.turbo_pstate = pstate_funcs.get_turbo(); cpu->pstate.scaling = pstate_funcs.get_scaling(); - cpu->pstate.max_freq = cpu->pstate.max_pstate * cpu->pstate.scaling; if (hwp_active && !hwp_mode_bdw) { unsigned int phy_max, current_max; @@ -1726,9 +1724,12 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu) intel_pstate_get_hwp_max(cpu, &phy_max, ¤t_max); cpu->pstate.turbo_freq = phy_max * cpu->pstate.scaling; cpu->pstate.turbo_pstate = phy_max; + cpu->pstate.max_pstate = HWP_GUARANTEED_PERF(READ_ONCE(cpu->hwp_cap_cached)); } else { cpu->pstate.turbo_freq = cpu->pstate.turbo_pstate * cpu->pstate.scaling; + cpu->pstate.max_pstate = pstate_funcs.get_max(); } + cpu->pstate.max_freq = cpu->pstate.max_pstate * cpu->pstate.scaling; if (pstate_funcs.get_aperf_mperf_shift) cpu->aperf_mperf_shift = pstate_funcs.get_aperf_mperf_shift(); |