intel_pstate: remove unneeded sample buffers

Remove unneeded sample buffers, intel_pstate operates on the most
recent sample only.  This save some memory and make the code more
readable.

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 11 insertions, 13 deletions

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 2cd36b9297f3..41f9eb295f0c 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -99,8 +99,7 @@ struct cpudata {
         u64     prev_aperf;
         u64     prev_mperf;
         unsigned long long prev_tsc;
-        int     sample_ptr;
-        struct sample samples[SAMPLE_COUNT];
+        struct sample sample;
 };
 
 static struct cpudata **all_cpu_data;
@@ -586,15 +585,14 @@ static inline void intel_pstate_sample(struct cpudata *cpu)
         mperf = mperf >> FRAC_BITS;
         tsc = tsc >> FRAC_BITS;
 
-        cpu->sample_ptr = (cpu->sample_ptr + 1) % SAMPLE_COUNT;
-        cpu->samples[cpu->sample_ptr].aperf = aperf;
-        cpu->samples[cpu->sample_ptr].mperf = mperf;
-        cpu->samples[cpu->sample_ptr].tsc = tsc;
-        cpu->samples[cpu->sample_ptr].aperf -= cpu->prev_aperf;
-        cpu->samples[cpu->sample_ptr].mperf -= cpu->prev_mperf;
-        cpu->samples[cpu->sample_ptr].tsc -= cpu->prev_tsc;
+        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->samples[cpu->sample_ptr]);
+        intel_pstate_calc_busy(cpu, &cpu->sample);
 
         cpu->prev_aperf = aperf;
         cpu->prev_mperf = mperf;
@@ -614,7 +612,7 @@ static inline int32_t intel_pstate_get_scaled_busy(struct cpudata *cpu)
 {
         int32_t core_busy, max_pstate, current_pstate;
 
-        core_busy = cpu->samples[cpu->sample_ptr].core_pct_busy;
+        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));
@@ -648,7 +646,7 @@ static void intel_pstate_timer_func(unsigned long __data)
 
         intel_pstate_sample(cpu);
 
-        sample = &cpu->samples[cpu->sample_ptr];
+        sample = &cpu->sample;
 
         intel_pstate_adjust_busy_pstate(cpu);
 
@@ -729,7 +727,7 @@ static unsigned int intel_pstate_get(unsigned int cpu_num)
         cpu = all_cpu_data[cpu_num];
         if (!cpu)
                 return 0;
-        sample = &cpu->samples[cpu->sample_ptr];
+        sample = &cpu->sample;
         return sample->freq;
 }