Messages in this thread Patch in this message | | | From | Chen Yu <> | Subject | [PATCH][v3] cpufreq: intel_pstate: Get percpu max freq via HWP MSR register if available | Date | Tue, 12 Jan 2021 13:21:27 +0800 |
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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 the MSR_HWP_CAPABILITIES is percpu scope according to Intel Software Developer Manual.
The turbo max freq is already percpu basis in current code, thus 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> --- v2: Per Srinivas' suggestion, avoid duplicated assignment of max_pstate. v3: Per Rafael's suggestion, do not add new argument in intel_pstate_get_hwp_max() to avoid redundant local vars. Per Srinivas' suggestion, refined the commit log to reflect the 'non-turbo' max frequency. -- drivers/cpufreq/intel_pstate.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index eaf32ef7a030..99e180f644c3 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1724,11 +1724,9 @@ 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; @@ -1736,9 +1734,12 @@ 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(); -- 2.17.1
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