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;