Merge tag 'v3.16-rc1' into i2c/for-next

[karo-tx-linux.git] / drivers / cpufreq / intel_pstate.c

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index eab8ccfe6bebed652b8fec4849a5fc9fb67d82f3..4e7f492ad5839d43ef02a092d1b8cd9fde735278 100644 (file)
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -32,18 +32,16 @@
 #include <asm/msr.h>
 #include <asm/cpu_device_id.h>
 
-#define SAMPLE_COUNT           3
-
 #define BYT_RATIOS             0x66a
 #define BYT_VIDS               0x66b
 #define BYT_TURBO_RATIOS       0x66c
 #define BYT_TURBO_VIDS         0x66d
 
 
-#define FRAC_BITS 6
+#define FRAC_BITS 8
 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
 #define fp_toint(X) ((X) >> FRAC_BITS)
-#define FP_ROUNDUP(X) ((X) += 1 << FRAC_BITS)
+
 
 static inline int32_t mul_fp(int32_t x, int32_t y)
 {
@@ -59,8 +57,8 @@ struct sample {
        int32_t core_pct_busy;
        u64 aperf;
        u64 mperf;
-       unsigned long long tsc;
        int freq;
+       ktime_t time;
 };
 
 struct pstate_data {
@@ -90,17 +88,15 @@ struct _pid {
 struct cpudata {
        int cpu;
 
-       char name[64];
-
        struct timer_list timer;
 
        struct pstate_data pstate;
        struct vid_data vid;
        struct _pid pid;
 
+       ktime_t last_sample_time;
        u64     prev_aperf;
        u64     prev_mperf;
-       unsigned long long prev_tsc;
        struct sample sample;
 };
 
@@ -200,7 +196,10 @@ static signed int pid_calc(struct _pid *pid, int32_t busy)
        pid->last_err = fp_error;
 
        result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
-
+       if (result >= 0)
+               result = result + (1 << (FRAC_BITS-1));
+       else
+               result = result - (1 << (FRAC_BITS-1));
        return (signed int)fp_toint(result);
 }
 
@@ -546,8 +545,6 @@ static inline void intel_pstate_pstate_decrease(struct cpudata *cpu, int steps)
 
 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
 {
-       sprintf(cpu->name, "Intel 2nd generation core");
-
        cpu->pstate.min_pstate = pstate_funcs.get_min();
        cpu->pstate.max_pstate = pstate_funcs.get_max();
        cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
@@ -557,50 +554,45 @@ static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
        intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
 }
 
-static inline void intel_pstate_calc_busy(struct cpudata *cpu,
-                                       struct sample *sample)
+static inline void intel_pstate_calc_busy(struct cpudata *cpu)
 {
-       int32_t core_pct;
-       int32_t c0_pct;
+       struct sample *sample = &cpu->sample;
+       int64_t core_pct;
+       int32_t rem;
 
-       core_pct = div_fp(int_tofp((sample->aperf)),
-                       int_tofp((sample->mperf)));
-       core_pct = mul_fp(core_pct, int_tofp(100));
-       FP_ROUNDUP(core_pct);
+       core_pct = int_tofp(sample->aperf) * int_tofp(100);
+       core_pct = div_u64_rem(core_pct, int_tofp(sample->mperf), &rem);
 
-       c0_pct = div_fp(int_tofp(sample->mperf), int_tofp(sample->tsc));
+       if ((rem << 1) >= int_tofp(sample->mperf))
+               core_pct += 1;
 
        sample->freq = fp_toint(
                mul_fp(int_tofp(cpu->pstate.max_pstate * 1000), core_pct));
 
-       sample->core_pct_busy = mul_fp(core_pct, c0_pct);
+       sample->core_pct_busy = (int32_t)core_pct;
 }
 
 static inline void intel_pstate_sample(struct cpudata *cpu)
 {
        u64 aperf, mperf;
-       unsigned long long tsc;
 
        rdmsrl(MSR_IA32_APERF, aperf);
        rdmsrl(MSR_IA32_MPERF, mperf);
-       tsc = native_read_tsc();
 
        aperf = aperf >> FRAC_BITS;
        mperf = mperf >> FRAC_BITS;
-       tsc = tsc >> FRAC_BITS;
 
+       cpu->last_sample_time = cpu->sample.time;
+       cpu->sample.time = ktime_get();
        cpu->sample.aperf = aperf;
        cpu->sample.mperf = mperf;
-       cpu->sample.tsc = tsc;
        cpu->sample.aperf -= cpu->prev_aperf;
        cpu->sample.mperf -= cpu->prev_mperf;
-       cpu->sample.tsc -= cpu->prev_tsc;
 
-       intel_pstate_calc_busy(cpu, &cpu->sample);
+       intel_pstate_calc_busy(cpu);
 
        cpu->prev_aperf = aperf;
        cpu->prev_mperf = mperf;
-       cpu->prev_tsc = tsc;
 }
 
 static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
@@ -614,13 +606,25 @@ static inline void intel_pstate_set_sample_time(struct cpudata *cpu)
 
 static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
 {
-       int32_t core_busy, max_pstate, current_pstate;
+       int32_t core_busy, max_pstate, current_pstate, sample_ratio;
+       u32 duration_us;
+       u32 sample_time;
 
        core_busy = cpu->sample.core_pct_busy;
        max_pstate = int_tofp(cpu->pstate.max_pstate);
        current_pstate = int_tofp(cpu->pstate.current_pstate);
        core_busy = mul_fp(core_busy, div_fp(max_pstate, current_pstate));
-       return FP_ROUNDUP(core_busy);
+
+       sample_time = (pid_params.sample_rate_ms  * USEC_PER_MSEC);
+       duration_us = (u32) ktime_us_delta(cpu->sample.time,
+                                       cpu->last_sample_time);
+       if (duration_us > sample_time * 3) {
+               sample_ratio = div_fp(int_tofp(sample_time),
+                               int_tofp(duration_us));
+               core_busy = mul_fp(core_busy, sample_ratio);
+       }
+
+       return core_busy;
 }
 
 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
@@ -674,24 +678,21 @@ static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
        ICPU(0x37, byt_params),
        ICPU(0x3a, core_params),
        ICPU(0x3c, core_params),
+       ICPU(0x3d, core_params),
        ICPU(0x3e, core_params),
        ICPU(0x3f, core_params),
        ICPU(0x45, core_params),
        ICPU(0x46, core_params),
+       ICPU(0x4f, core_params),
+       ICPU(0x56, core_params),
        {}
 };
 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
 
 static int intel_pstate_init_cpu(unsigned int cpunum)
 {
-
-       const struct x86_cpu_id *id;
        struct cpudata *cpu;
 
-       id = x86_match_cpu(intel_pstate_cpu_ids);
-       if (!id)
-               return -ENODEV;
-
        all_cpu_data[cpunum] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
        if (!all_cpu_data[cpunum])
                return -ENOMEM;