From 17ffd35809c34b9564edb10727d02eb62958ba5c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 5 Jan 2021 19:20:29 +0100 Subject: [PATCH 1/3] cpufreq: intel_pstate: Use HWP capabilities in intel_cpufreq_adjust_perf() If turbo P-states cannot be used, either due to the configuration of the processor, or because intel_pstate is not allowed to used them, the maximum available P-state with HWP enabled corresponds to the HWP_CAP.GUARANTEED value which is not static. It can be adjusted by an out-of-band agent or during an Intel Speed Select performance level change, so long as it remains less than or equal to HWP_CAP.MAX. However, if turbo P-states cannot be used, intel_cpufreq_adjust_perf() always uses pstate.max_pstate (set during the initialization of the driver only) as the maximum available P-state, so it may miss a change of the HWP_CAP.GUARANTEED value. Prevent that from happening by modifyig intel_cpufreq_adjust_perf() to always read the "guaranteed" and "maximum turbo" performance levels from the cached HWP_CAP value. Fixes: a365ab6b9dfb ("cpufreq: intel_pstate: Implement the ->adjust_perf() callback") Signed-off-by: Rafael J. Wysocki Acked-by: Srinivas Pandruvada --- 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 1a660466dd75..32bc11851b8d 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2653,12 +2653,13 @@ static void intel_cpufreq_adjust_perf(unsigned int cpunum, unsigned long capacity) { struct cpudata *cpu = all_cpu_data[cpunum]; + u64 hwp_cap = READ_ONCE(cpu->hwp_cap_cached); int old_pstate = cpu->pstate.current_pstate; int cap_pstate, min_pstate, max_pstate, target_pstate; update_turbo_state(); - cap_pstate = global.turbo_disabled ? cpu->pstate.max_pstate : - cpu->pstate.turbo_pstate; + cap_pstate = global.turbo_disabled ? HWP_GUARANTEED_PERF(hwp_cap) : + HWP_HIGHEST_PERF(hwp_cap); /* Optimization: Avoid unnecessary divisions. */ From 943bdd0cecad06da8392a33093230e30e501eccc Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Tue, 5 Jan 2021 10:19:57 +0000 Subject: [PATCH 2/3] cpufreq: powernow-k8: pass policy rather than use cpufreq_cpu_get() Currently there is an unlikely case where cpufreq_cpu_get() returns a NULL policy and this will cause a NULL pointer dereference later on. Fix this by passing the policy to transition_frequency_fidvid() from the caller and hence eliminating the need for the cpufreq_cpu_get() and cpufreq_cpu_put(). Thanks to Viresh Kumar for suggesting the fix. Addresses-Coverity: ("Dereference null return") Fixes: b43a7ffbf33b ("cpufreq: Notify all policy->cpus in cpufreq_notify_transition()") Suggested-by: Viresh Kumar Signed-off-by: Colin Ian King Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/powernow-k8.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c index 0acc9e241cd7..b9ccb6a3dad9 100644 --- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -878,9 +878,9 @@ static int get_transition_latency(struct powernow_k8_data *data) /* Take a frequency, and issue the fid/vid transition command */ static int transition_frequency_fidvid(struct powernow_k8_data *data, - unsigned int index) + unsigned int index, + struct cpufreq_policy *policy) { - struct cpufreq_policy *policy; u32 fid = 0; u32 vid = 0; int res; @@ -912,9 +912,6 @@ static int transition_frequency_fidvid(struct powernow_k8_data *data, freqs.old = find_khz_freq_from_fid(data->currfid); freqs.new = find_khz_freq_from_fid(fid); - policy = cpufreq_cpu_get(smp_processor_id()); - cpufreq_cpu_put(policy); - cpufreq_freq_transition_begin(policy, &freqs); res = transition_fid_vid(data, fid, vid); cpufreq_freq_transition_end(policy, &freqs, res); @@ -969,7 +966,7 @@ static long powernowk8_target_fn(void *arg) powernow_k8_acpi_pst_values(data, newstate); - ret = transition_frequency_fidvid(data, newstate); + ret = transition_frequency_fidvid(data, newstate, pol); if (ret) { pr_err("transition frequency failed\n"); From c4151604f0603d5700072183a05828ff87d764e4 Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Mon, 21 Dec 2020 06:13:20 +0100 Subject: [PATCH 3/3] cpufreq: intel_pstate: remove obsolete functions percent_fp() was used in intel_pstate_pid_reset(), which was removed in commit 9d0ef7af1f2d ("cpufreq: intel_pstate: Do not use PID-based P-state selection") and hence, percent_fp() is unused since then. percent_ext_fp() was last used in intel_pstate_update_perf_limits(), which was refactored in commit 1a4fe38add8b ("cpufreq: intel_pstate: Remove max/min fractions to limit performance"), and hence, percent_ext_fp() is unused since then. make CC=clang W=1 points us those unused functions: drivers/cpufreq/intel_pstate.c:79:23: warning: unused function 'percent_fp' [-Wunused-function] static inline int32_t percent_fp(int percent) ^ drivers/cpufreq/intel_pstate.c:94:23: warning: unused function 'percent_ext_fp' [-Wunused-function] static inline int32_t percent_ext_fp(int percent) ^ Remove those obsolete functions. Signed-off-by: Lukas Bulwahn Reviewed-by: Nathan Chancellor Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 32bc11851b8d..be05e038d956 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -76,11 +76,6 @@ static inline int ceiling_fp(int32_t x) return ret; } -static inline int32_t percent_fp(int percent) -{ - return div_fp(percent, 100); -} - static inline u64 mul_ext_fp(u64 x, u64 y) { return (x * y) >> EXT_FRAC_BITS; @@ -91,11 +86,6 @@ static inline u64 div_ext_fp(u64 x, u64 y) return div64_u64(x << EXT_FRAC_BITS, y); } -static inline int32_t percent_ext_fp(int percent) -{ - return div_ext_fp(percent, 100); -} - /** * struct sample - Store performance sample * @core_avg_perf: Ratio of APERF/MPERF which is the actual average