cpufreq: amd-pstate: Unify computation of {max,min,nominal,lowest_nonlinear}_freq

Currently the amd_get_{min, max, nominal, lowest_nonlinear}_freq()
helpers computes the values of min_freq, max_freq, nominal_freq and
lowest_nominal_freq respectively afresh from
cppc_get_perf_caps(). This is not necessary as there are fields in
cpudata to cache these values.

To simplify this, add a single helper function named
amd_pstate_init_freq() which computes all these frequencies at once, and
caches it in cpudata.

Use the cached values everywhere else in the code.

Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Li Meng <li.meng@amd.com>
Tested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Co-developed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 2015c9fcc3c9145e997d15d834aeace8728fc346..891fad6f90e146f9d668374c59278510b57f806b 100644 (file)
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -606,74 +606,22 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 
 static int amd_get_min_freq(struct amd_cpudata *cpudata)
 {
-       struct cppc_perf_caps cppc_perf;
-
-       int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
-       if (ret)
-               return ret;
-
-       /* Switch to khz */
-       return cppc_perf.lowest_freq * 1000;
+       return READ_ONCE(cpudata->min_freq);
 }
 
 static int amd_get_max_freq(struct amd_cpudata *cpudata)
 {
-       struct cppc_perf_caps cppc_perf;
-       u32 max_perf, max_freq, nominal_freq, nominal_perf;
-       u64 boost_ratio;
-
-       int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
-       if (ret)
-               return ret;
-
-       nominal_freq = cppc_perf.nominal_freq;
-       nominal_perf = READ_ONCE(cpudata->nominal_perf);
-       max_perf = READ_ONCE(cpudata->highest_perf);
-
-       boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT,
-                             nominal_perf);
-
-       max_freq = nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT;
-
-       /* Switch to khz */
-       return max_freq * 1000;
+       return READ_ONCE(cpudata->max_freq);
 }
 
 static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
 {
-       struct cppc_perf_caps cppc_perf;
-
-       int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
-       if (ret)
-               return ret;
-
-       /* Switch to khz */
-       return cppc_perf.nominal_freq * 1000;
+       return READ_ONCE(cpudata->nominal_freq);
 }
 
 static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
 {
-       struct cppc_perf_caps cppc_perf;
-       u32 lowest_nonlinear_freq, lowest_nonlinear_perf,
-           nominal_freq, nominal_perf;
-       u64 lowest_nonlinear_ratio;
-
-       int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
-       if (ret)
-               return ret;
-
-       nominal_freq = cppc_perf.nominal_freq;
-       nominal_perf = READ_ONCE(cpudata->nominal_perf);
-
-       lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
-
-       lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf << SCHED_CAPACITY_SHIFT,
-                                        nominal_perf);
-
-       lowest_nonlinear_freq = nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT;
-
-       /* Switch to khz */
-       return lowest_nonlinear_freq * 1000;
+       return READ_ONCE(cpudata->lowest_nonlinear_freq);
 }
 
 static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
@@ -828,6 +776,53 @@ free_cpufreq_put:
        mutex_unlock(&amd_pstate_driver_lock);
 }
 
+/**
+ * amd_pstate_init_freq: Initialize the max_freq, min_freq,
+ *                       nominal_freq and lowest_nonlinear_freq for
+ *                       the @cpudata object.
+ *
+ *  Requires: highest_perf, lowest_perf, nominal_perf and
+ *            lowest_nonlinear_perf members of @cpudata to be
+ *            initialized.
+ *
+ *  Returns 0 on success, non-zero value on failure.
+ */
+static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
+{
+       int ret;
+       u32 min_freq;
+       u32 highest_perf, max_freq;
+       u32 nominal_perf, nominal_freq;
+       u32 lowest_nonlinear_perf, lowest_nonlinear_freq;
+       u32 boost_ratio, lowest_nonlinear_ratio;
+       struct cppc_perf_caps cppc_perf;
+
+
+       ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
+       if (ret)
+               return ret;
+
+       min_freq = cppc_perf.lowest_freq * 1000;
+       nominal_freq = cppc_perf.nominal_freq;
+       nominal_perf = READ_ONCE(cpudata->nominal_perf);
+
+       highest_perf = READ_ONCE(cpudata->highest_perf);
+       boost_ratio = div_u64(highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);
+       max_freq = (nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT) * 1000;
+
+       lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
+       lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf << SCHED_CAPACITY_SHIFT,
+                                        nominal_perf);
+       lowest_nonlinear_freq = (nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT) * 1000;
+
+       WRITE_ONCE(cpudata->min_freq, min_freq);
+       WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
+       WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
+       WRITE_ONCE(cpudata->max_freq, max_freq);
+
+       return 0;
+}
+
 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 {
        int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
@@ -855,6 +850,10 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
        if (ret)
                goto free_cpudata1;
 
+       ret = amd_pstate_init_freq(cpudata);
+       if (ret)
+               goto free_cpudata1;
+
        min_freq = amd_get_min_freq(cpudata);
        max_freq = amd_get_max_freq(cpudata);
        nominal_freq = amd_get_nominal_freq(cpudata);
@@ -896,13 +895,8 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
                goto free_cpudata2;
        }
 
-       /* Initial processor data capability frequencies */
-       cpudata->max_freq = max_freq;
-       cpudata->min_freq = min_freq;
        cpudata->max_limit_freq = max_freq;
        cpudata->min_limit_freq = min_freq;
-       cpudata->nominal_freq = nominal_freq;
-       cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
 
        policy->driver_data = cpudata;
 
@@ -1317,6 +1311,10 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
        if (ret)
                goto free_cpudata1;
 
+       ret = amd_pstate_init_freq(cpudata);
+       if (ret)
+               goto free_cpudata1;
+
        min_freq = amd_get_min_freq(cpudata);
        max_freq = amd_get_max_freq(cpudata);
        nominal_freq = amd_get_nominal_freq(cpudata);
@@ -1333,12 +1331,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
        /* It will be updated by governor */
        policy->cur = policy->cpuinfo.min_freq;
 
-       /* Initial processor data capability frequencies */
-       cpudata->max_freq = max_freq;
-       cpudata->min_freq = min_freq;
-       cpudata->nominal_freq = nominal_freq;
-       cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
-
        policy->driver_data = cpudata;
 
        cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0);