cpufreq/amd-pstate: Modularize perf<->freq conversion

Delegate the perf<->frequency conversion to helper functions to reduce
code duplication, and improve readability.

Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20250205112523.201101-8-dhananjay.ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 69409d43eae8528f3d297b02eb46dac3724efc31..9ab95ec1f8285d33da6b31ddc7b13a6a18877f6f 100644 (file)
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -142,6 +142,20 @@ static struct quirk_entry quirk_amd_7k62 = {
        .lowest_freq = 550,
 };
 
+static inline u8 freq_to_perf(struct amd_cpudata *cpudata, unsigned int freq_val)
+{
+       u8 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * cpudata->nominal_perf,
+                                       cpudata->nominal_freq);
+
+       return clamp_t(u8, perf_val, cpudata->lowest_perf, cpudata->highest_perf);
+}
+
+static inline u32 perf_to_freq(struct amd_cpudata *cpudata, u8 perf_val)
+{
+       return DIV_ROUND_UP_ULL((u64)cpudata->nominal_freq * perf_val,
+                               cpudata->nominal_perf);
+}
+
 static int __init dmi_matched_7k62_bios_bug(const struct dmi_system_id *dmi)
 {
        /**
@@ -534,14 +548,12 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
 static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
                              u8 des_perf, u8 max_perf, bool fast_switch, int gov_flags)
 {
-       unsigned long max_freq;
        struct cpufreq_policy *policy = cpufreq_cpu_get(cpudata->cpu);
        u8 nominal_perf = READ_ONCE(cpudata->nominal_perf);
 
        des_perf = clamp_t(u8, des_perf, min_perf, max_perf);
 
-       max_freq = READ_ONCE(cpudata->max_limit_freq);
-       policy->cur = div_u64(des_perf * max_freq, max_perf);
+       policy->cur = perf_to_freq(cpudata, des_perf);
 
        if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) {
                min_perf = des_perf;
@@ -591,14 +603,11 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
 
 static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
 {
-       u8 max_limit_perf, min_limit_perf, max_perf;
-       u32 max_freq;
+       u8 max_limit_perf, min_limit_perf;
        struct amd_cpudata *cpudata = policy->driver_data;
 
-       max_perf = READ_ONCE(cpudata->highest_perf);
-       max_freq = READ_ONCE(cpudata->max_freq);
-       max_limit_perf = div_u64(policy->max * max_perf, max_freq);
-       min_limit_perf = div_u64(policy->min * max_perf, max_freq);
+       max_limit_perf = freq_to_perf(cpudata, policy->max);
+       min_limit_perf = freq_to_perf(cpudata, policy->min);
 
        if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
                min_limit_perf = min(cpudata->nominal_perf, max_limit_perf);
@@ -616,21 +625,15 @@ static int amd_pstate_update_freq(struct cpufreq_policy *policy,
 {
        struct cpufreq_freqs freqs;
        struct amd_cpudata *cpudata = policy->driver_data;
-       u8 des_perf, cap_perf;
-
-       if (!cpudata->max_freq)
-               return -ENODEV;
+       u8 des_perf;
 
        if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
                amd_pstate_update_min_max_limit(policy);
 
-       cap_perf = READ_ONCE(cpudata->highest_perf);
-
        freqs.old = policy->cur;
        freqs.new = target_freq;
 
-       des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
-                                    cpudata->max_freq);
+       des_perf = freq_to_perf(cpudata, target_freq);
 
        WARN_ON(fast_switch && !policy->fast_switch_enabled);
        /*
@@ -905,7 +908,6 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 {
        int ret;
        u32 min_freq, max_freq;
-       u8 highest_perf, nominal_perf, lowest_nonlinear_perf;
        u32 nominal_freq, lowest_nonlinear_freq;
        struct cppc_perf_caps cppc_perf;
 
@@ -923,16 +925,17 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
        else
                nominal_freq = cppc_perf.nominal_freq;
 
-       highest_perf = READ_ONCE(cpudata->highest_perf);
-       nominal_perf = READ_ONCE(cpudata->nominal_perf);
-       max_freq = div_u64((u64)highest_perf * nominal_freq, nominal_perf);
+       min_freq *= 1000;
+       nominal_freq *= 1000;
+
+       WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
+       WRITE_ONCE(cpudata->min_freq, min_freq);
+
+       max_freq = perf_to_freq(cpudata, cpudata->highest_perf);
+       lowest_nonlinear_freq = perf_to_freq(cpudata, cpudata->lowest_nonlinear_perf);
 
-       lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
-       lowest_nonlinear_freq = div_u64((u64)nominal_freq * lowest_nonlinear_perf, nominal_perf);
-       WRITE_ONCE(cpudata->min_freq, min_freq * 1000);
-       WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq * 1000);
-       WRITE_ONCE(cpudata->nominal_freq, nominal_freq * 1000);
-       WRITE_ONCE(cpudata->max_freq, max_freq * 1000);
+       WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
+       WRITE_ONCE(cpudata->max_freq, max_freq);
 
        /**
         * Below values need to be initialized correctly, otherwise driver will fail to load