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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-12-14 23:09:26 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2020-12-15 21:24:19 +0300
commita365ab6b9dfbaf8fb4fb4cd5d8a4c55dc4fb8b1c (patch)
tree6909d1ae71356b79bbc9f8a1deb6d6b31cb9a166 /drivers/cpufreq
parentee2cc4276ba4909438f5894a218877660e1536d9 (diff)
downloadlinux-a365ab6b9dfbaf8fb4fb4cd5d8a4c55dc4fb8b1c.tar.xz
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 <rafael.j.wysocki@intel.com> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/intel_pstate.c70
1 files 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;