x86/amd: Move amd_get_highest_perf() out of amd-pstate

amd_pstate_get_highest_perf() is a helper used to get the highest perf
value on AMD systems.  It's used in amd-pstate as part of preferred
core handling, but applicable for acpi-cpufreq as well.

Move it out to cppc handling code as amd_get_highest_perf().

Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

arch/x86/kernel/acpi/cppc.c

@@ -116,6 +116,36 @@ void init_freq_invariance_cppc(void)
 	mutex_unlock(&freq_invariance_lock);
 }
 
+/*
+ * Get the highest performance register value.
+ * @cpu: CPU from which to get highest performance.
+ * @highest_perf: Return address for highest performance value.
+ *
+ * Return: 0 for success, negative error code otherwise.
+ */
+int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
+{
+	u64 val;
+	int ret;
+
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
+		ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &val);
+		if (ret)
+			goto out;
+
+		val = AMD_CPPC_HIGHEST_PERF(val);
+	} else {
+		ret = cppc_get_highest_perf(cpu, &val);
+		if (ret)
+			goto out;
+	}
+
+	WRITE_ONCE(*highest_perf, (u32)val);
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(amd_get_highest_perf);
+
 /**
  * amd_get_boost_ratio_numerator: Get the numerator to use for boost ratio calculation
  * @cpu: CPU to get numerator for.

drivers/cpufreq/amd-pstate.c

@@ -811,44 +811,14 @@ static void amd_pstste_sched_prefcore_workfn(struct work_struct *work)
 }
 static DECLARE_WORK(sched_prefcore_work, amd_pstste_sched_prefcore_workfn);
 
-/*
- * Get the highest performance register value.
- * @cpu: CPU from which to get highest performance.
- * @highest_perf: Return address.
- *
- * Return: 0 for success, -EIO otherwise.
- */
-static int amd_pstate_get_highest_perf(int cpu, u32 *highest_perf)
-{
-	int ret;
-
-	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
-		u64 cap1;
-
-		ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
-		if (ret)
-			return ret;
-		WRITE_ONCE(*highest_perf, AMD_CPPC_HIGHEST_PERF(cap1));
-	} else {
-		u64 cppc_highest_perf;
-
-		ret = cppc_get_highest_perf(cpu, &cppc_highest_perf);
-		if (ret)
-			return ret;
-		WRITE_ONCE(*highest_perf, cppc_highest_perf);
-	}
-
-	return (ret);
-}
-
 #define CPPC_MAX_PERF	U8_MAX
 
 static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
 {
 	int ret, prio;
 	u32 highest_perf;
 
-	ret = amd_pstate_get_highest_perf(cpudata->cpu, &highest_perf);
+	ret = amd_get_highest_perf(cpudata->cpu, &highest_perf);
 	if (ret)
 		return;
 
@@ -892,7 +862,7 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
 		goto free_cpufreq_put;
 
-	ret = amd_pstate_get_highest_perf(cpu, &cur_high);
+	ret = amd_get_highest_perf(cpu, &cur_high);
 	if (ret)
 		goto free_cpufreq_put;
 

include/acpi/cppc_acpi.h

@@ -159,6 +159,7 @@ extern int cppc_get_epp_perf(int cpunum, u64 *epp_perf);
 extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable);
 extern int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps);
 extern int cppc_set_auto_sel(int cpu, bool enable);
+extern int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf);
 extern int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator);
 #else /* !CONFIG_ACPI_CPPC_LIB */
 static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
@@ -233,6 +234,10 @@ static inline int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf
 {
 	return -EOPNOTSUPP;
 }
+static inline int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
+{
+	return -ENODEV;
+}
 static inline int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
 {
 	return -EOPNOTSUPP;