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Date: Tue, 28 Mar 2017 00:22:16 +0200
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
Doug Smythies <dsmythies@...us.net>
Subject: [PATCH 15/16] cpufreq: intel_pstate: Do not walk policy->cpus
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
intel_pstate_hwp_set() is the only function walking policy->cpus
in intel_pstate. The rest of the code simply assumes one CPU per
policy, including the initialization code.
Therefore it doesn't make sense for intel_pstate_hwp_set() to
walk policy->cpus as it is guaranteed to have only one bit set
for policy->cpu.
For this reason, rearrange intel_pstate_hwp_set() to take the CPU
number as the argument and drop the loop over policy->cpus from it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
drivers/cpufreq/intel_pstate.c | 132 +++++++++++++++++++----------------------
1 file changed, 64 insertions(+), 68 deletions(-)
Index: linux-pm/drivers/cpufreq/intel_pstate.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/intel_pstate.c
+++ linux-pm/drivers/cpufreq/intel_pstate.c
@@ -792,84 +792,80 @@ static struct freq_attr *hwp_cpufreq_att
NULL,
};
-static void intel_pstate_hwp_set(struct cpufreq_policy *policy)
+static void intel_pstate_hwp_set(unsigned int cpu)
{
- int min, hw_min, max, hw_max, cpu;
+ struct cpudata *cpu_data = all_cpu_data[cpu];
+ int min, hw_min, max, hw_max;
u64 value, cap;
+ s16 epp;
- for_each_cpu(cpu, policy->cpus) {
- struct cpudata *cpu_data = all_cpu_data[cpu];
- s16 epp;
-
- rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap);
- hw_min = HWP_LOWEST_PERF(cap);
- if (global.no_turbo)
- hw_max = HWP_GUARANTEED_PERF(cap);
- else
- hw_max = HWP_HIGHEST_PERF(cap);
-
- max = fp_ext_toint(hw_max * cpu_data->max_perf);
- if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE)
- min = max;
- else
- min = fp_ext_toint(hw_max * cpu_data->min_perf);
-
- rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
+ rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap);
+ hw_min = HWP_LOWEST_PERF(cap);
+ if (global.no_turbo)
+ hw_max = HWP_GUARANTEED_PERF(cap);
+ else
+ hw_max = HWP_HIGHEST_PERF(cap);
- value &= ~HWP_MIN_PERF(~0L);
- value |= HWP_MIN_PERF(min);
+ max = fp_ext_toint(hw_max * cpu_data->max_perf);
+ if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE)
+ min = max;
+ else
+ min = fp_ext_toint(hw_max * cpu_data->min_perf);
- value &= ~HWP_MAX_PERF(~0L);
- value |= HWP_MAX_PERF(max);
+ rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
- if (cpu_data->epp_policy == cpu_data->policy)
- goto skip_epp;
+ value &= ~HWP_MIN_PERF(~0L);
+ value |= HWP_MIN_PERF(min);
- cpu_data->epp_policy = cpu_data->policy;
+ value &= ~HWP_MAX_PERF(~0L);
+ value |= HWP_MAX_PERF(max);
- if (cpu_data->epp_saved >= 0) {
- epp = cpu_data->epp_saved;
- cpu_data->epp_saved = -EINVAL;
- goto update_epp;
- }
+ if (cpu_data->epp_policy == cpu_data->policy)
+ goto skip_epp;
- if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE) {
- epp = intel_pstate_get_epp(cpu_data, value);
- cpu_data->epp_powersave = epp;
- /* If EPP read was failed, then don't try to write */
- if (epp < 0)
- goto skip_epp;
-
-
- epp = 0;
- } else {
- /* skip setting EPP, when saved value is invalid */
- if (cpu_data->epp_powersave < 0)
- goto skip_epp;
-
- /*
- * No need to restore EPP when it is not zero. This
- * means:
- * - Policy is not changed
- * - user has manually changed
- * - Error reading EPB
- */
- epp = intel_pstate_get_epp(cpu_data, value);
- if (epp)
- goto skip_epp;
+ cpu_data->epp_policy = cpu_data->policy;
- epp = cpu_data->epp_powersave;
- }
+ if (cpu_data->epp_saved >= 0) {
+ epp = cpu_data->epp_saved;
+ cpu_data->epp_saved = -EINVAL;
+ goto update_epp;
+ }
+
+ if (cpu_data->policy == CPUFREQ_POLICY_PERFORMANCE) {
+ epp = intel_pstate_get_epp(cpu_data, value);
+ cpu_data->epp_powersave = epp;
+ /* If EPP read was failed, then don't try to write */
+ if (epp < 0)
+ goto skip_epp;
+
+ epp = 0;
+ } else {
+ /* skip setting EPP, when saved value is invalid */
+ if (cpu_data->epp_powersave < 0)
+ goto skip_epp;
+
+ /*
+ * No need to restore EPP when it is not zero. This
+ * means:
+ * - Policy is not changed
+ * - user has manually changed
+ * - Error reading EPB
+ */
+ epp = intel_pstate_get_epp(cpu_data, value);
+ if (epp)
+ goto skip_epp;
+
+ epp = cpu_data->epp_powersave;
+ }
update_epp:
- if (static_cpu_has(X86_FEATURE_HWP_EPP)) {
- value &= ~GENMASK_ULL(31, 24);
- value |= (u64)epp << 24;
- } else {
- intel_pstate_set_epb(cpu, epp);
- }
-skip_epp:
- wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
+ if (static_cpu_has(X86_FEATURE_HWP_EPP)) {
+ value &= ~GENMASK_ULL(31, 24);
+ value |= (u64)epp << 24;
+ } else {
+ intel_pstate_set_epb(cpu, epp);
}
+skip_epp:
+ wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
}
static int intel_pstate_hwp_save_state(struct cpufreq_policy *policy)
@@ -892,7 +888,7 @@ static int intel_pstate_resume(struct cp
mutex_lock(&intel_pstate_limits_lock);
all_cpu_data[policy->cpu]->epp_policy = 0;
- intel_pstate_hwp_set(policy);
+ intel_pstate_hwp_set(policy->cpu);
mutex_unlock(&intel_pstate_limits_lock);
@@ -2057,7 +2053,7 @@ static int intel_pstate_set_policy(struc
intel_pstate_set_update_util_hook(policy->cpu);
if (hwp_active)
- intel_pstate_hwp_set(policy);
+ intel_pstate_hwp_set(policy->cpu);
mutex_unlock(&intel_pstate_limits_lock);
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