From a365ab6b9dfbaf8fb4fb4cd5d8a4c55dc4fb8b1c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 14 Dec 2020 21:09:26 +0100 Subject: [PATCH] cpufreq: intel_pstate: Implement the ->adjust_perf() callback Make intel_pstate expose the ->adjust_perf() callback when it operates in the passive mode with HWP enabled which causes the schedutil governor to use that callback instead of ->fast_switch(). The minimum and target performance-level values passed by the governor to ->adjust_perf() are converted to HWP.REQ.MIN and HWP.REQ.DESIRED, respectively, which allows the processor to adjust its configuration to maximize energy-efficiency while providing sufficient capacity. Signed-off-by: Rafael J. Wysocki Acked-by: Srinivas Pandruvada Acked-by: Viresh Kumar --- drivers/cpufreq/intel_pstate.c | 70 ++++++++++++++++++++++++++++------ 1 file changed, 58 insertions(+), 12 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 2a4db856222f..d5ec0c962ec5 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2526,20 +2526,19 @@ static void intel_cpufreq_trace(struct cpudata *cpu, unsigned int trace_type, in fp_toint(cpu->iowait_boost * 100)); } -static void intel_cpufreq_adjust_hwp(struct cpudata *cpu, u32 target_pstate, - bool strict, bool fast_switch) +static void intel_cpufreq_adjust_hwp(struct cpudata *cpu, u32 min, u32 max, + u32 desired, bool fast_switch) { u64 prev = READ_ONCE(cpu->hwp_req_cached), value = prev; value &= ~HWP_MIN_PERF(~0L); - value |= HWP_MIN_PERF(target_pstate); + value |= HWP_MIN_PERF(min); - /* - * The entire MSR needs to be updated in order to update the HWP min - * field in it, so opportunistically update the max too if needed. - */ value &= ~HWP_MAX_PERF(~0L); - value |= HWP_MAX_PERF(strict ? target_pstate : cpu->max_perf_ratio); + value |= HWP_MAX_PERF(max); + + value &= ~HWP_DESIRED_PERF(~0L); + value |= HWP_DESIRED_PERF(desired); if (value == prev) return; @@ -2569,11 +2568,15 @@ static int intel_cpufreq_update_pstate(struct cpufreq_policy *policy, int old_pstate = cpu->pstate.current_pstate; target_pstate = intel_pstate_prepare_request(cpu, target_pstate); - if (hwp_active) - intel_cpufreq_adjust_hwp(cpu, target_pstate, - policy->strict_target, fast_switch); - else if (target_pstate != old_pstate) + if (hwp_active) { + int max_pstate = policy->strict_target ? + target_pstate : cpu->max_perf_ratio; + + intel_cpufreq_adjust_hwp(cpu, target_pstate, max_pstate, 0, + fast_switch); + } else if (target_pstate != old_pstate) { intel_cpufreq_adjust_perf_ctl(cpu, target_pstate, fast_switch); + } cpu->pstate.current_pstate = target_pstate; @@ -2634,6 +2637,47 @@ static unsigned int intel_cpufreq_fast_switch(struct cpufreq_policy *policy, return target_pstate * cpu->pstate.scaling; } +static void intel_cpufreq_adjust_perf(unsigned int cpunum, + unsigned long min_perf, + unsigned long target_perf, + unsigned long capacity) +{ + struct cpudata *cpu = all_cpu_data[cpunum]; + 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; + + /* Optimization: Avoid unnecessary divisions. */ + + target_pstate = cap_pstate; + if (target_perf < capacity) + target_pstate = DIV_ROUND_UP(cap_pstate * target_perf, capacity); + + min_pstate = cap_pstate; + if (min_perf < capacity) + min_pstate = DIV_ROUND_UP(cap_pstate * min_perf, capacity); + + if (min_pstate < cpu->pstate.min_pstate) + min_pstate = cpu->pstate.min_pstate; + + if (min_pstate < cpu->min_perf_ratio) + min_pstate = cpu->min_perf_ratio; + + max_pstate = min(cap_pstate, cpu->max_perf_ratio); + if (max_pstate < min_pstate) + max_pstate = min_pstate; + + target_pstate = clamp_t(int, target_pstate, min_pstate, max_pstate); + + intel_cpufreq_adjust_hwp(cpu, min_pstate, max_pstate, target_pstate, true); + + cpu->pstate.current_pstate = target_pstate; + intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_FAST_SWITCH, old_pstate); +} + static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy) { int max_state, turbo_max, min_freq, max_freq, ret; @@ -3032,6 +3076,8 @@ static int __init intel_pstate_init(void) intel_pstate.attr = hwp_cpufreq_attrs; intel_cpufreq.attr = hwp_cpufreq_attrs; intel_cpufreq.flags |= CPUFREQ_NEED_UPDATE_LIMITS; + intel_cpufreq.fast_switch = NULL; + intel_cpufreq.adjust_perf = intel_cpufreq_adjust_perf; if (!default_driver) default_driver = &intel_pstate; -- 2.20.1