diff options
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 320 |
1 files changed, 20 insertions, 300 deletions
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 0c50637e6bda..8f95265d5f52 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -37,8 +37,7 @@ #include <asm/cpufeature.h> #include <asm/intel-family.h> -#define INTEL_PSTATE_DEFAULT_SAMPLING_INTERVAL (10 * NSEC_PER_MSEC) -#define INTEL_PSTATE_HWP_SAMPLING_INTERVAL (50 * NSEC_PER_MSEC) +#define INTEL_PSTATE_SAMPLING_INTERVAL (10 * NSEC_PER_MSEC) #define INTEL_CPUFREQ_TRANSITION_LATENCY 20000 #define INTEL_CPUFREQ_TRANSITION_DELAY 500 @@ -173,28 +172,6 @@ struct vid_data { }; /** - * struct _pid - Stores PID data - * @setpoint: Target set point for busyness or performance - * @integral: Storage for accumulated error values - * @p_gain: PID proportional gain - * @i_gain: PID integral gain - * @d_gain: PID derivative gain - * @deadband: PID deadband - * @last_err: Last error storage for integral part of PID calculation - * - * Stores PID coefficients and last error for PID controller. - */ -struct _pid { - int setpoint; - int32_t integral; - int32_t p_gain; - int32_t i_gain; - int32_t d_gain; - int deadband; - int32_t last_err; -}; - -/** * struct global_params - Global parameters, mostly tunable via sysfs. * @no_turbo: Whether or not to use turbo P-states. * @turbo_disabled: Whethet or not turbo P-states are available at all, @@ -223,7 +200,6 @@ struct global_params { * @last_update: Time of the last update. * @pstate: Stores P state limits for this CPU * @vid: Stores VID limits for this CPU - * @pid: Stores PID parameters for this CPU * @last_sample_time: Last Sample time * @aperf_mperf_shift: Number of clock cycles after aperf, merf is incremented * This shift is a multiplier to mperf delta to @@ -258,7 +234,6 @@ struct cpudata { struct pstate_data pstate; struct vid_data vid; - struct _pid pid; u64 last_update; u64 last_sample_time; @@ -284,28 +259,6 @@ struct cpudata { static struct cpudata **all_cpu_data; /** - * struct pstate_adjust_policy - Stores static PID configuration data - * @sample_rate_ms: PID calculation sample rate in ms - * @sample_rate_ns: Sample rate calculation in ns - * @deadband: PID deadband - * @setpoint: PID Setpoint - * @p_gain_pct: PID proportional gain - * @i_gain_pct: PID integral gain - * @d_gain_pct: PID derivative gain - * - * Stores per CPU model static PID configuration data. - */ -struct pstate_adjust_policy { - int sample_rate_ms; - s64 sample_rate_ns; - int deadband; - int setpoint; - int p_gain_pct; - int d_gain_pct; - int i_gain_pct; -}; - -/** * struct pstate_funcs - Per CPU model specific callbacks * @get_max: Callback to get maximum non turbo effective P state * @get_max_physical: Callback to get maximum non turbo physical P state @@ -314,7 +267,6 @@ struct pstate_adjust_policy { * @get_scaling: Callback to get frequency scaling factor * @get_val: Callback to convert P state to actual MSR write value * @get_vid: Callback to get VID data for Atom platforms - * @update_util: Active mode utilization update callback. * * Core and Atom CPU models have different way to get P State limits. This * structure is used to store those callbacks. @@ -328,20 +280,9 @@ struct pstate_funcs { int (*get_aperf_mperf_shift)(void); u64 (*get_val)(struct cpudata*, int pstate); void (*get_vid)(struct cpudata *); - void (*update_util)(struct update_util_data *data, u64 time, - unsigned int flags); }; static struct pstate_funcs pstate_funcs __read_mostly; -static struct pstate_adjust_policy pid_params __read_mostly = { - .sample_rate_ms = 10, - .sample_rate_ns = 10 * NSEC_PER_MSEC, - .deadband = 0, - .setpoint = 97, - .p_gain_pct = 20, - .d_gain_pct = 0, - .i_gain_pct = 0, -}; static int hwp_active __read_mostly; static bool per_cpu_limits __read_mostly; @@ -509,56 +450,6 @@ static inline void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy) } #endif -static signed int pid_calc(struct _pid *pid, int32_t busy) -{ - signed int result; - int32_t pterm, dterm, fp_error; - int32_t integral_limit; - - fp_error = pid->setpoint - busy; - - if (abs(fp_error) <= pid->deadband) - return 0; - - pterm = mul_fp(pid->p_gain, fp_error); - - pid->integral += fp_error; - - /* - * 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; - if (pid->integral < -integral_limit) - pid->integral = -integral_limit; - - dterm = mul_fp(pid->d_gain, fp_error - pid->last_err); - pid->last_err = fp_error; - - result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm; - result = result + (1 << (FRAC_BITS-1)); - return (signed int)fp_toint(result); -} - -static inline void intel_pstate_pid_reset(struct cpudata *cpu) -{ - struct _pid *pid = &cpu->pid; - - pid->p_gain = percent_fp(pid_params.p_gain_pct); - pid->d_gain = percent_fp(pid_params.d_gain_pct); - pid->i_gain = percent_fp(pid_params.i_gain_pct); - pid->setpoint = int_tofp(pid_params.setpoint); - pid->last_err = pid->setpoint - int_tofp(100); - pid->deadband = int_tofp(pid_params.deadband); - pid->integral = 0; -} - static inline void update_turbo_state(void) { u64 misc_en; @@ -911,82 +802,6 @@ static void intel_pstate_update_policies(void) cpufreq_update_policy(cpu); } -/************************** debugfs begin ************************/ -static int pid_param_set(void *data, u64 val) -{ - unsigned int cpu; - - *(u32 *)data = val; - pid_params.sample_rate_ns = pid_params.sample_rate_ms * NSEC_PER_MSEC; - for_each_possible_cpu(cpu) - if (all_cpu_data[cpu]) - intel_pstate_pid_reset(all_cpu_data[cpu]); - - return 0; -} - -static int pid_param_get(void *data, u64 *val) -{ - *val = *(u32 *)data; - return 0; -} -DEFINE_SIMPLE_ATTRIBUTE(fops_pid_param, pid_param_get, pid_param_set, "%llu\n"); - -static struct dentry *debugfs_parent; - -struct pid_param { - char *name; - void *value; - struct dentry *dentry; -}; - -static struct pid_param pid_files[] = { - {"sample_rate_ms", &pid_params.sample_rate_ms, }, - {"d_gain_pct", &pid_params.d_gain_pct, }, - {"i_gain_pct", &pid_params.i_gain_pct, }, - {"deadband", &pid_params.deadband, }, - {"setpoint", &pid_params.setpoint, }, - {"p_gain_pct", &pid_params.p_gain_pct, }, - {NULL, NULL, } -}; - -static void intel_pstate_debug_expose_params(void) -{ - int i; - - debugfs_parent = debugfs_create_dir("pstate_snb", NULL); - if (IS_ERR_OR_NULL(debugfs_parent)) - return; - - for (i = 0; pid_files[i].name; i++) { - struct dentry *dentry; - - dentry = debugfs_create_file(pid_files[i].name, 0660, - debugfs_parent, pid_files[i].value, - &fops_pid_param); - if (!IS_ERR(dentry)) - pid_files[i].dentry = dentry; - } -} - -static void intel_pstate_debug_hide_params(void) -{ - int i; - - if (IS_ERR_OR_NULL(debugfs_parent)) - return; - - for (i = 0; pid_files[i].name; i++) { - debugfs_remove(pid_files[i].dentry); - pid_files[i].dentry = NULL; - } - - debugfs_remove(debugfs_parent); - debugfs_parent = NULL; -} - -/************************** debugfs end ************************/ - /************************** sysfs begin ************************/ #define show_one(file_name, object) \ static ssize_t show_##file_name \ @@ -1622,7 +1437,7 @@ static inline int32_t get_avg_pstate(struct cpudata *cpu) cpu->sample.core_avg_perf); } -static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu) +static inline int32_t get_target_pstate(struct cpudata *cpu) { struct sample *sample = &cpu->sample; int32_t busy_frac, boost; @@ -1660,44 +1475,6 @@ static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu) return target; } -static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu) -{ - int32_t perf_scaled, max_pstate, current_pstate, sample_ratio; - u64 duration_ns; - - /* - * perf_scaled is the ratio of the average P-state during the last - * sampling period to the P-state requested last time (in percent). - * - * That measures the system's response to the previous P-state - * selection. - */ - max_pstate = cpu->pstate.max_pstate_physical; - current_pstate = cpu->pstate.current_pstate; - perf_scaled = mul_ext_fp(cpu->sample.core_avg_perf, - div_fp(100 * max_pstate, current_pstate)); - - /* - * Since our utilization update callback will not run unless we are - * in C0, check 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 performance metric. - */ - duration_ns = cpu->sample.time - cpu->last_sample_time; - if ((s64)duration_ns > pid_params.sample_rate_ns * 3) { - sample_ratio = div_fp(pid_params.sample_rate_ns, duration_ns); - perf_scaled = mul_fp(perf_scaled, sample_ratio); - } else { - sample_ratio = div_fp(100 * (cpu->sample.mperf << cpu->aperf_mperf_shift), - cpu->sample.tsc); - if (sample_ratio < int_tofp(1)) - perf_scaled = 0; - } - - cpu->sample.busy_scaled = perf_scaled; - return cpu->pstate.current_pstate - pid_calc(&cpu->pid, perf_scaled); -} - static int intel_pstate_prepare_request(struct cpudata *cpu, int pstate) { int max_pstate = intel_pstate_get_base_pstate(cpu); @@ -1717,13 +1494,15 @@ static void intel_pstate_update_pstate(struct cpudata *cpu, int pstate) wrmsrl(MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, pstate)); } -static void intel_pstate_adjust_pstate(struct cpudata *cpu, int target_pstate) +static void intel_pstate_adjust_pstate(struct cpudata *cpu) { int from = cpu->pstate.current_pstate; struct sample *sample; + int target_pstate; update_turbo_state(); + target_pstate = get_target_pstate(cpu); target_pstate = intel_pstate_prepare_request(cpu, target_pstate); trace_cpu_frequency(target_pstate * cpu->pstate.scaling, cpu->cpu); intel_pstate_update_pstate(cpu, target_pstate); @@ -1740,27 +1519,6 @@ static void intel_pstate_adjust_pstate(struct cpudata *cpu, int target_pstate) fp_toint(cpu->iowait_boost * 100)); } -static void intel_pstate_update_util_pid(struct update_util_data *data, - u64 time, unsigned int flags) -{ - struct cpudata *cpu = container_of(data, struct cpudata, update_util); - u64 delta_ns = time - cpu->sample.time; - - /* Don't allow remote callbacks */ - if (smp_processor_id() != cpu->cpu) - return; - - if ((s64)delta_ns < pid_params.sample_rate_ns) - return; - - if (intel_pstate_sample(cpu, time)) { - int target_pstate; - - target_pstate = get_target_pstate_use_performance(cpu); - intel_pstate_adjust_pstate(cpu, target_pstate); - } -} - static void intel_pstate_update_util(struct update_util_data *data, u64 time, unsigned int flags) { @@ -1773,6 +1531,15 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time, if (flags & SCHED_CPUFREQ_IOWAIT) { cpu->iowait_boost = int_tofp(1); + cpu->last_update = time; + /* + * The last time the busy was 100% so P-state was max anyway + * so avoid overhead of computation. + */ + if (fp_toint(cpu->sample.busy_scaled) == 100) + return; + + goto set_pstate; } else if (cpu->iowait_boost) { /* Clear iowait_boost if the CPU may have been idle. */ delta_ns = time - cpu->last_update; @@ -1781,15 +1548,12 @@ static void intel_pstate_update_util(struct update_util_data *data, u64 time, } cpu->last_update = time; delta_ns = time - cpu->sample.time; - if ((s64)delta_ns < INTEL_PSTATE_DEFAULT_SAMPLING_INTERVAL) + if ((s64)delta_ns < INTEL_PSTATE_SAMPLING_INTERVAL) return; - if (intel_pstate_sample(cpu, time)) { - int target_pstate; - - target_pstate = get_target_pstate_use_cpu_load(cpu); - intel_pstate_adjust_pstate(cpu, target_pstate); - } +set_pstate: + if (intel_pstate_sample(cpu, time)) + intel_pstate_adjust_pstate(cpu); } static struct pstate_funcs core_funcs = { @@ -1799,7 +1563,6 @@ static struct pstate_funcs core_funcs = { .get_turbo = core_get_turbo_pstate, .get_scaling = core_get_scaling, .get_val = core_get_val, - .update_util = intel_pstate_update_util_pid, }; static const struct pstate_funcs silvermont_funcs = { @@ -1810,7 +1573,6 @@ static const struct pstate_funcs silvermont_funcs = { .get_val = atom_get_val, .get_scaling = silvermont_get_scaling, .get_vid = atom_get_vid, - .update_util = intel_pstate_update_util, }; static const struct pstate_funcs airmont_funcs = { @@ -1821,7 +1583,6 @@ static const struct pstate_funcs airmont_funcs = { .get_val = atom_get_val, .get_scaling = airmont_get_scaling, .get_vid = atom_get_vid, - .update_util = intel_pstate_update_util, }; static const struct pstate_funcs knl_funcs = { @@ -1832,7 +1593,6 @@ static const struct pstate_funcs knl_funcs = { .get_aperf_mperf_shift = knl_get_aperf_mperf_shift, .get_scaling = core_get_scaling, .get_val = core_get_val, - .update_util = intel_pstate_update_util_pid, }; static const struct pstate_funcs bxt_funcs = { @@ -1842,7 +1602,6 @@ static const struct pstate_funcs bxt_funcs = { .get_turbo = core_get_turbo_pstate, .get_scaling = core_get_scaling, .get_val = core_get_val, - .update_util = intel_pstate_update_util, }; #define ICPU(model, policy) \ @@ -1886,8 +1645,6 @@ static const struct x86_cpu_id intel_pstate_cpu_ee_disable_ids[] = { {} }; -static bool pid_in_use(void); - static int intel_pstate_init_cpu(unsigned int cpunum) { struct cpudata *cpu; @@ -1918,8 +1675,6 @@ static int intel_pstate_init_cpu(unsigned int cpunum) intel_pstate_disable_ee(cpunum); intel_pstate_hwp_enable(cpu); - } else if (pid_in_use()) { - intel_pstate_pid_reset(cpu); } intel_pstate_get_cpu_pstates(cpu); @@ -1942,7 +1697,7 @@ static void intel_pstate_set_update_util_hook(unsigned int cpu_num) /* Prevent intel_pstate_update_util() from using stale data. */ cpu->sample.time = 0; cpufreq_add_update_util_hook(cpu_num, &cpu->update_util, - pstate_funcs.update_util); + intel_pstate_update_util); cpu->update_util_set = true; } @@ -2267,12 +2022,6 @@ static struct cpufreq_driver intel_cpufreq = { static struct cpufreq_driver *default_driver = &intel_pstate; -static bool pid_in_use(void) -{ - return intel_pstate_driver == &intel_pstate && - pstate_funcs.update_util == intel_pstate_update_util_pid; -} - static void intel_pstate_driver_cleanup(void) { unsigned int cpu; @@ -2307,9 +2056,6 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver) global.min_perf_pct = min_perf_pct_min(); - if (pid_in_use()) - intel_pstate_debug_expose_params(); - return 0; } @@ -2318,9 +2064,6 @@ static int intel_pstate_unregister_driver(void) if (hwp_active) return -EBUSY; - if (pid_in_use()) - intel_pstate_debug_hide_params(); - cpufreq_unregister_driver(intel_pstate_driver); intel_pstate_driver_cleanup(); @@ -2388,24 +2131,6 @@ static int __init intel_pstate_msrs_not_valid(void) return 0; } -#ifdef CONFIG_ACPI -static void intel_pstate_use_acpi_profile(void) -{ - switch (acpi_gbl_FADT.preferred_profile) { - case PM_MOBILE: - case PM_TABLET: - case PM_APPLIANCE_PC: - case PM_DESKTOP: - case PM_WORKSTATION: - pstate_funcs.update_util = intel_pstate_update_util; - } -} -#else -static void intel_pstate_use_acpi_profile(void) -{ -} -#endif - static void __init copy_cpu_funcs(struct pstate_funcs *funcs) { pstate_funcs.get_max = funcs->get_max; @@ -2415,10 +2140,7 @@ static void __init copy_cpu_funcs(struct pstate_funcs *funcs) pstate_funcs.get_scaling = funcs->get_scaling; pstate_funcs.get_val = funcs->get_val; pstate_funcs.get_vid = funcs->get_vid; - pstate_funcs.update_util = funcs->update_util; pstate_funcs.get_aperf_mperf_shift = funcs->get_aperf_mperf_shift; - - intel_pstate_use_acpi_profile(); } #ifdef CONFIG_ACPI @@ -2562,9 +2284,7 @@ static int __init intel_pstate_init(void) if (x86_match_cpu(hwp_support_ids)) { copy_cpu_funcs(&core_funcs); - if (no_hwp) { - pstate_funcs.update_util = intel_pstate_update_util; - } else { + if (!no_hwp) { hwp_active++; intel_pstate.attr = hwp_cpufreq_attrs; goto hwp_cpu_matched; |