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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-01-07 19:42:15 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-01-12 19:34:04 +0100 |
| commit | 9dd04ec6bc6fa7b310e5595f2ad9bef13eacd3a0 (patch) | |
| tree | 70ca4c03580209e00d15dc466460b72fdf50a3f9 | |
| parent | Linux 5.11-rc3 (diff) | |
| download | linux-9dd04ec6bc6fa7b310e5595f2ad9bef13eacd3a0.tar.xz linux-9dd04ec6bc6fa7b310e5595f2ad9bef13eacd3a0.zip | |
cpufreq: intel_pstate: Always read hwp_cap_cached with READ_ONCE()
Because intel_pstate_get_hwp_max() which updates hwp_cap_cached
may run in parallel with the readers of it, annotate all of the
read accesses to it with READ_ONCE().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index be05e038d956..74bf54e6c993 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -914,7 +914,7 @@ static void intel_pstate_hwp_offline(struct cpudata *cpu) } value &= ~GENMASK_ULL(31, 0); - min_perf = HWP_LOWEST_PERF(cpu->hwp_cap_cached); + min_perf = HWP_LOWEST_PERF(READ_ONCE(cpu->hwp_cap_cached)); /* Set hwp_max = hwp_min */ value |= HWP_MAX_PERF(min_perf); @@ -1750,6 +1750,7 @@ static int hwp_boost_hold_time_ns = 3 * NSEC_PER_MSEC; static inline void intel_pstate_hwp_boost_up(struct cpudata *cpu) { u64 hwp_req = READ_ONCE(cpu->hwp_req_cached); + u64 hwp_cap = READ_ONCE(cpu->hwp_cap_cached); u32 max_limit = (hwp_req & 0xff00) >> 8; u32 min_limit = (hwp_req & 0xff); u32 boost_level1; @@ -1776,14 +1777,14 @@ static inline void intel_pstate_hwp_boost_up(struct cpudata *cpu) cpu->hwp_boost_min = min_limit; /* level at half way mark between min and guranteed */ - boost_level1 = (HWP_GUARANTEED_PERF(cpu->hwp_cap_cached) + min_limit) >> 1; + boost_level1 = (HWP_GUARANTEED_PERF(hwp_cap) + min_limit) >> 1; if (cpu->hwp_boost_min < boost_level1) cpu->hwp_boost_min = boost_level1; - else if (cpu->hwp_boost_min < HWP_GUARANTEED_PERF(cpu->hwp_cap_cached)) - cpu->hwp_boost_min = HWP_GUARANTEED_PERF(cpu->hwp_cap_cached); - else if (cpu->hwp_boost_min == HWP_GUARANTEED_PERF(cpu->hwp_cap_cached) && - max_limit != HWP_GUARANTEED_PERF(cpu->hwp_cap_cached)) + else if (cpu->hwp_boost_min < HWP_GUARANTEED_PERF(hwp_cap)) + cpu->hwp_boost_min = HWP_GUARANTEED_PERF(hwp_cap); + else if (cpu->hwp_boost_min == HWP_GUARANTEED_PERF(hwp_cap) && + max_limit != HWP_GUARANTEED_PERF(hwp_cap)) cpu->hwp_boost_min = max_limit; else return; |