#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_CPUFREQ_TRANSITION_LATENCY 20000
#define INTEL_CPUFREQ_TRANSITION_DELAY 500
int32_t ratio;
};
-/**
- * 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.
* @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
struct pstate_data pstate;
struct vid_data vid;
- struct _pid pid;
u64 last_update;
u64 last_sample_time;
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_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.
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;
}
#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;
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 \
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);
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;
-
- 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)
{
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;
if ((s64)delta_ns < INTEL_PSTATE_DEFAULT_SAMPLING_INTERVAL)
return;
+set_pstate:
if (intel_pstate_sample(cpu, time)) {
int target_pstate;
.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 = {
.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 = {
.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 = {
.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 = {
.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) \
{}
};
-static bool pid_in_use(void);
-
static int intel_pstate_init_cpu(unsigned int cpunum)
{
struct cpudata *cpu;
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);
/* 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;
}
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;
global.min_perf_pct = min_perf_pct_min();
- if (pid_in_use())
- intel_pstate_debug_expose_params();
-
return 0;
}
if (hwp_active)
return -EBUSY;
- if (pid_in_use())
- intel_pstate_debug_hide_params();
-
cpufreq_unregister_driver(intel_pstate_driver);
intel_pstate_driver_cleanup();
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;
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
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;
git.samba.org / sfrench / cifs-2.6.git / blobdiff