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cpufreq: intel_pstate: Implement the ->adjust_perf() callback

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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>
This commit is contained in:
Rafael J. Wysocki 2020-12-14 21:09:26 +01:00
parent ee2cc4276b
commit a365ab6b9d
1 changed files with 58 additions and 12 deletions
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70
drivers/cpufreq/intel_pstate.c
View file

@ -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;