summaryrefslogtreecommitdiff
path: root/drivers/cpufreq/intel_pstate.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpufreq/intel_pstate.c')
-rw-r--r--drivers/cpufreq/intel_pstate.c93
1 files changed, 87 insertions, 6 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1405b393c93d..872c5772c5d3 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -148,6 +148,8 @@ struct perf_limits {
int32_t min_perf;
int max_policy_pct;
int max_sysfs_pct;
+ int min_policy_pct;
+ int min_sysfs_pct;
};
static struct perf_limits limits = {
@@ -159,6 +161,8 @@ static struct perf_limits limits = {
.min_perf = 0,
.max_policy_pct = 100,
.max_sysfs_pct = 100,
+ .min_policy_pct = 0,
+ .min_sysfs_pct = 0,
};
static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
@@ -199,7 +203,14 @@ static signed int pid_calc(struct _pid *pid, int32_t busy)
pid->integral += fp_error;
- /* limit the integral term */
+ /*
+ * We limit the integral here so that it will never
+ * get higher than 30. This prevents it from becoming
+ * too large an input over long periods of time and allows
+ * it to get factored out sooner.
+ *
+ * The value of 30 was chosen through experimentation.
+ */
integral_limit = int_tofp(30);
if (pid->integral > integral_limit)
pid->integral = integral_limit;
@@ -331,6 +342,33 @@ static void __init intel_pstate_debug_expose_params(void)
return sprintf(buf, "%u\n", limits.object); \
}
+static ssize_t show_turbo_pct(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct cpudata *cpu;
+ int total, no_turbo, turbo_pct;
+ uint32_t turbo_fp;
+
+ cpu = all_cpu_data[0];
+
+ total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
+ no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
+ turbo_fp = div_fp(int_tofp(no_turbo), int_tofp(total));
+ turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
+ return sprintf(buf, "%u\n", turbo_pct);
+}
+
+static ssize_t show_num_pstates(struct kobject *kobj,
+ struct attribute *attr, char *buf)
+{
+ struct cpudata *cpu;
+ int total;
+
+ cpu = all_cpu_data[0];
+ total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
+ return sprintf(buf, "%u\n", total);
+}
+
static ssize_t show_no_turbo(struct kobject *kobj,
struct attribute *attr, char *buf)
{
@@ -397,7 +435,9 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
ret = sscanf(buf, "%u", &input);
if (ret != 1)
return -EINVAL;
- limits.min_perf_pct = clamp_t(int, input, 0 , 100);
+
+ limits.min_sysfs_pct = clamp_t(int, input, 0 , 100);
+ limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
if (hwp_active)
@@ -411,11 +451,15 @@ show_one(min_perf_pct, min_perf_pct);
define_one_global_rw(no_turbo);
define_one_global_rw(max_perf_pct);
define_one_global_rw(min_perf_pct);
+define_one_global_ro(turbo_pct);
+define_one_global_ro(num_pstates);
static struct attribute *intel_pstate_attributes[] = {
&no_turbo.attr,
&max_perf_pct.attr,
&min_perf_pct.attr,
+ &turbo_pct.attr,
+ &num_pstates.attr,
NULL
};
@@ -616,6 +660,11 @@ static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
if (limits.no_turbo || limits.turbo_disabled)
max_perf = cpu->pstate.max_pstate;
+ /*
+ * performance can be limited by user through sysfs, by cpufreq
+ * policy, or by cpu specific default values determined through
+ * experimentation.
+ */
max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), limits.max_perf));
*max = clamp_t(int, max_perf_adj,
cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
@@ -717,11 +766,29 @@ static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
u32 duration_us;
u32 sample_time;
+ /*
+ * core_busy is the ratio of actual performance to max
+ * max_pstate is the max non turbo pstate available
+ * current_pstate was the pstate that was requested during
+ * the last sample period.
+ *
+ * We normalize core_busy, which was our actual percent
+ * performance to what we requested during the last sample
+ * period. The result will be a percentage of busy at a
+ * specified pstate.
+ */
core_busy = cpu->sample.core_pct_busy;
max_pstate = int_tofp(cpu->pstate.max_pstate);
current_pstate = int_tofp(cpu->pstate.current_pstate);
core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
+ /*
+ * Since we have a deferred timer, it will not fire unless
+ * we are in C0. So, determine if the actual elapsed time
+ * is significantly greater (3x) than our sample interval. If it
+ * is, then we were idle for a long enough period of time
+ * to adjust our busyness.
+ */
sample_time = pid_params.sample_rate_ms * USEC_PER_MSEC;
duration_us = (u32) ktime_us_delta(cpu->sample.time,
cpu->last_sample_time);
@@ -795,6 +862,7 @@ static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
ICPU(0x46, core_params),
ICPU(0x47, core_params),
ICPU(0x4c, byt_params),
+ ICPU(0x4e, core_params),
ICPU(0x4f, core_params),
ICPU(0x56, core_params),
{}
@@ -857,7 +925,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
if (!policy->cpuinfo.max_freq)
return -ENODEV;
- if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
+ if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
+ policy->max >= policy->cpuinfo.max_freq) {
+ limits.min_policy_pct = 100;
limits.min_perf_pct = 100;
limits.min_perf = int_tofp(1);
limits.max_policy_pct = 100;
@@ -867,8 +937,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
return 0;
}
- limits.min_perf_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
- limits.min_perf_pct = clamp_t(int, limits.min_perf_pct, 0 , 100);
+ limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
+ limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100);
+ limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct);
limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100));
limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq;
@@ -948,6 +1019,8 @@ static struct cpufreq_driver intel_pstate_driver = {
static int __initdata no_load;
static int __initdata no_hwp;
+static int __initdata hwp_only;
+static unsigned int force_load;
static int intel_pstate_msrs_not_valid(void)
{
@@ -1094,7 +1167,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
case PSS:
return intel_pstate_no_acpi_pss();
case PPC:
- return intel_pstate_has_acpi_ppc();
+ return intel_pstate_has_acpi_ppc() &&
+ (!force_load);
}
}
@@ -1143,6 +1217,9 @@ static int __init intel_pstate_init(void)
if (cpu_has(c,X86_FEATURE_HWP) && !no_hwp)
intel_pstate_hwp_enable();
+ if (!hwp_active && hwp_only)
+ goto out;
+
rc = cpufreq_register_driver(&intel_pstate_driver);
if (rc)
goto out;
@@ -1175,6 +1252,10 @@ static int __init intel_pstate_setup(char *str)
no_load = 1;
if (!strcmp(str, "no_hwp"))
no_hwp = 1;
+ if (!strcmp(str, "force"))
+ force_load = 1;
+ if (!strcmp(str, "hwp_only"))
+ hwp_only = 1;
return 0;
}
early_param("intel_pstate", intel_pstate_setup);