diff options
author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2015-10-14 16:12:01 -0700 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-10-15 01:53:18 +0200 |
commit | 37afb00032424d684a48d649fcfb8b5e4f17c409 (patch) | |
tree | 27e39c9822569de2b6a18e5cc38c2074ce34d69e /drivers/cpufreq | |
parent | 3bcc6fa971c06151d6bf90cb0dc80807f71b93f6 (diff) | |
download | linux-37afb00032424d684a48d649fcfb8b5e4f17c409.tar.bz2 |
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>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r-- | drivers/cpufreq/Kconfig.x86 | 1 | ||||
-rw-r--r-- | drivers/cpufreq/intel_pstate.c | 171 |
2 files changed, 171 insertions, 1 deletions
diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86 index c59bdcb83217..adbd1de1cea5 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 1369afdc1e19..041cb4107991 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); |