From: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Date: Wed, 14 Oct 2015 23:12:01 +0000 (-0700)
Subject: cpufreq: intel_pstate: Use ACPI perf configuration
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=37afb0003242;p=linux.git
cpufreq: intel_pstate: Use ACPI perf configuration
Use ACPI _PSS to limit the Intel P State turbo, max and min ratios.
This driver uses acpi processor perf lib calls to register performance.
The following logic is used to adjust Intel P state driver limits:
- If there is no turbo entry in _PSS, then disable Intel P state turbo
and limit to non turbo max
- If the non turbo max ratio is more than _PSS max non turbo value, then
set the max non turbo ratio to _PSS non turbo max
- If the min ratio is less than _PSS min then change the min ratio
matching _PSS min
- Scale the _PSS turbo frequency to max turbo frequency based on control
value.
This feature can be disabled by using kernel parameters:
intel_pstate=no_acpi
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86
index c59bdcb832170..adbd1de1cea55 100644
--- a/drivers/cpufreq/Kconfig.x86
+++ b/drivers/cpufreq/Kconfig.x86
@@ -5,6 +5,7 @@
config X86_INTEL_PSTATE
bool "Intel P state control"
depends on X86
+ select ACPI_PROCESSOR if ACPI
help
This driver provides a P state for Intel core processors.
The driver implements an internal governor and will become
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 1369afdc1e195..041cb4107991e 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -34,6 +34,10 @@
#include <asm/cpu_device_id.h>
#include <asm/cpufeature.h>
+#if IS_ENABLED(CONFIG_ACPI)
+#include <acpi/processor.h>
+#endif
+
#define BYT_RATIOS 0x66a
#define BYT_VIDS 0x66b
#define BYT_TURBO_RATIOS 0x66c
@@ -113,6 +117,9 @@ struct cpudata {
u64 prev_mperf;
u64 prev_tsc;
struct sample sample;
+#if IS_ENABLED(CONFIG_ACPI)
+ struct acpi_processor_performance acpi_perf_data;
+#endif
};
static struct cpudata **all_cpu_data;
@@ -143,6 +150,7 @@ struct cpu_defaults {
static struct pstate_adjust_policy pid_params;
static struct pstate_funcs pstate_funcs;
static int hwp_active;
+static int no_acpi_perf;
struct perf_limits {
int no_turbo;
@@ -170,6 +178,153 @@ static struct perf_limits limits = {
.min_sysfs_pct = 0,
};
+#if IS_ENABLED(CONFIG_ACPI)
+/*
+ * The max target pstate ratio is a 8 bit value in both PLATFORM_INFO MSR and
+ * in TURBO_RATIO_LIMIT MSR, which pstate driver stores in max_pstate and
+ * max_turbo_pstate fields. The PERF_CTL MSR contains 16 bit value for P state
+ * ratio, out of it only high 8 bits are used. For example 0x1700 is setting
+ * target ratio 0x17. The _PSS control value stores in a format which can be
+ * directly written to PERF_CTL MSR. But in intel_pstate driver this shift
+ * occurs during write to PERF_CTL (E.g. for cores core_set_pstate()).
+ * This function converts the _PSS control value to intel pstate driver format
+ * for comparison and assignment.
+ */
+static int convert_to_native_pstate_format(struct cpudata *cpu, int index)
+{
+ return cpu->acpi_perf_data.states[index].control >> 8;
+}
+
+static int intel_pstate_init_perf_limits(struct cpufreq_policy *policy)
+{
+ struct cpudata *cpu;
+ int ret;
+ bool turbo_absent = false;
+ int max_pstate_index;
+ int min_pss_ctl, max_pss_ctl, turbo_pss_ctl;
+ int i;
+
+ cpu = all_cpu_data[policy->cpu];
+
+ pr_debug("intel_pstate: default limits 0x%x 0x%x 0x%x\n",
+ cpu->pstate.min_pstate, cpu->pstate.max_pstate,
+ cpu->pstate.turbo_pstate);
+
+ if (!cpu->acpi_perf_data.shared_cpu_map &&
+ zalloc_cpumask_var_node(&cpu->acpi_perf_data.shared_cpu_map,
+ GFP_KERNEL, cpu_to_node(policy->cpu))) {
+ return -ENOMEM;
+ }
+
+ ret = acpi_processor_register_performance(&cpu->acpi_perf_data,
+ policy->cpu);
+ if (ret)
+ return ret;
+
+ /*
+ * Check if the control value in _PSS is for PERF_CTL MSR, which should
+ * guarantee that the states returned by it map to the states in our
+ * list directly.
+ */
+ if (cpu->acpi_perf_data.control_register.space_id !=
+ ACPI_ADR_SPACE_FIXED_HARDWARE)
+ return -EIO;
+
+ pr_debug("intel_pstate: CPU%u - ACPI _PSS perf data\n", policy->cpu);
+ for (i = 0; i < cpu->acpi_perf_data.state_count; i++)
+ pr_debug(" %cP%d: %u MHz, %u mW, 0x%x\n",
+ (i == cpu->acpi_perf_data.state ? '*' : ' '), i,
+ (u32) cpu->acpi_perf_data.states[i].core_frequency,
+ (u32) cpu->acpi_perf_data.states[i].power,
+ (u32) cpu->acpi_perf_data.states[i].control);
+
+ /*
+ * If there is only one entry _PSS, simply ignore _PSS and continue as
+ * usual without taking _PSS into account
+ */
+ if (cpu->acpi_perf_data.state_count < 2)
+ return 0;
+
+ turbo_pss_ctl = convert_to_native_pstate_format(cpu, 0);
+ min_pss_ctl = convert_to_native_pstate_format(cpu,
+ cpu->acpi_perf_data.state_count - 1);
+ /* Check if there is a turbo freq in _PSS */
+ if (turbo_pss_ctl <= cpu->pstate.max_pstate &&
+ turbo_pss_ctl > cpu->pstate.min_pstate) {
+ pr_debug("intel_pstate: no turbo range exists in _PSS\n");
+ limits.no_turbo = limits.turbo_disabled = 1;
+ cpu->pstate.turbo_pstate = cpu->pstate.max_pstate;
+ turbo_absent = true;
+ }
+
+ /* Check if the max non turbo p state < Intel P state max */
+ max_pstate_index = turbo_absent ? 0 : 1;
+ max_pss_ctl = convert_to_native_pstate_format(cpu, max_pstate_index);
+ if (max_pss_ctl < cpu->pstate.max_pstate &&
+ max_pss_ctl > cpu->pstate.min_pstate)
+ cpu->pstate.max_pstate = max_pss_ctl;
+
+ /* check If min perf > Intel P State min */
+ if (min_pss_ctl > cpu->pstate.min_pstate &&
+ min_pss_ctl < cpu->pstate.max_pstate) {
+ cpu->pstate.min_pstate = min_pss_ctl;
+ policy->cpuinfo.min_freq = min_pss_ctl * cpu->pstate.scaling;
+ }
+
+ if (turbo_absent)
+ policy->cpuinfo.max_freq = cpu->pstate.max_pstate *
+ cpu->pstate.scaling;
+ else {
+ policy->cpuinfo.max_freq = cpu->pstate.turbo_pstate *
+ cpu->pstate.scaling;
+ /*
+ * The _PSS table doesn't contain whole turbo frequency range.
+ * This just contains +1 MHZ above the max non turbo frequency,
+ * with control value corresponding to max turbo ratio. But
+ * when cpufreq set policy is called, it will call with this
+ * max frequency, which will cause a reduced performance as
+ * this driver uses real max turbo frequency as the max
+ * frequeny. So correct this frequency in _PSS table to
+ * correct max turbo frequency based on the turbo ratio.
+ * Also need to convert to MHz as _PSS freq is in MHz.
+ */
+ cpu->acpi_perf_data.states[0].core_frequency =
+ turbo_pss_ctl * 100;
+ }
+
+ pr_debug("intel_pstate: Updated limits using _PSS 0x%x 0x%x 0x%x\n",
+ cpu->pstate.min_pstate, cpu->pstate.max_pstate,
+ cpu->pstate.turbo_pstate);
+ pr_debug("intel_pstate: policy max_freq=%d Khz min_freq = %d KHz\n",
+ policy->cpuinfo.max_freq, policy->cpuinfo.min_freq);
+
+ return 0;
+}
+
+static int intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
+{
+ struct cpudata *cpu;
+
+ if (!no_acpi_perf)
+ return 0;
+
+ cpu = all_cpu_data[policy->cpu];
+ acpi_processor_unregister_performance(policy->cpu);
+ return 0;
+}
+
+#else
+static int intel_pstate_init_perf_limits(struct cpufreq_policy *policy)
+{
+ return 0;
+}
+
+static int intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
+{
+ return 0;
+}
+#endif
+
static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
int deadband, int integral) {
pid->setpoint = setpoint;
@@ -1115,18 +1270,30 @@ static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
policy->cpuinfo.max_freq =
cpu->pstate.turbo_pstate * cpu->pstate.scaling;
+ if (!no_acpi_perf)
+ intel_pstate_init_perf_limits(policy);
+ /*
+ * If there is no acpi perf data or error, we ignore and use Intel P
+ * state calculated limits, So this is not fatal error.
+ */
policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
cpumask_set_cpu(policy->cpu, policy->cpus);
return 0;
}
+static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
+{
+ return intel_pstate_exit_perf_limits(policy);
+}
+
static struct cpufreq_driver intel_pstate_driver = {
.flags = CPUFREQ_CONST_LOOPS,
.verify = intel_pstate_verify_policy,
.setpolicy = intel_pstate_set_policy,
.get = intel_pstate_get,
.init = intel_pstate_cpu_init,
+ .exit = intel_pstate_cpu_exit,
.stop_cpu = intel_pstate_stop_cpu,
.name = "intel_pstate",
};
@@ -1168,7 +1335,6 @@ static void copy_cpu_funcs(struct pstate_funcs *funcs)
}
#if IS_ENABLED(CONFIG_ACPI)
-#include <acpi/processor.h>
static bool intel_pstate_no_acpi_pss(void)
{
@@ -1360,6 +1526,9 @@ static int __init intel_pstate_setup(char *str)
force_load = 1;
if (!strcmp(str, "hwp_only"))
hwp_only = 1;
+ if (!strcmp(str, "no_acpi"))
+ no_acpi_perf = 1;
+
return 0;
}
early_param("intel_pstate", intel_pstate_setup);