1 files changed, 246 insertions, 111 deletions

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 9ad62dbe8bfb..68c616b572f2 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -51,6 +51,7 @@
 
 #define AMD_PSTATE_TRANSITION_LATENCY	20000
 #define AMD_PSTATE_TRANSITION_DELAY	1000
+#define AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY 600
 #define CPPC_HIGHEST_PERF_PERFORMANCE	196
 #define CPPC_HIGHEST_PERF_DEFAULT	166
 
@@ -85,15 +86,6 @@ struct quirk_entry {
 	u32 lowest_freq;
 };
 
-/*
- * TODO: We need more time to fine tune processors with shared memory solution
- * with community together.
- *
- * There are some performance drops on the CPU benchmarks which reports from
- * Suse. We are co-working with them to fine tune the shared memory solution. So
- * we disable it by default to go acpi-cpufreq on these processors and add a
- * module parameter to be able to enable it manually for debugging.
- */
 static struct cpufreq_driver *current_pstate_driver;
 static struct cpufreq_driver amd_pstate_driver;
 static struct cpufreq_driver amd_pstate_epp_driver;
@@ -157,7 +149,7 @@ static int __init dmi_matched_7k62_bios_bug(const struct dmi_system_id *dmi)
 	 * broken BIOS lack of nominal_freq and lowest_freq capabilities
 	 * definition in ACPI tables
 	 */
-	if (boot_cpu_has(X86_FEATURE_ZEN2)) {
+	if (cpu_feature_enabled(X86_FEATURE_ZEN2)) {
 		quirks = dmi->driver_data;
 		pr_info("Overriding nominal and lowest frequencies for %s\n", dmi->ident);
 		return 1;
@@ -199,7 +191,7 @@ static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
 	u64 epp;
 	int ret;
 
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		if (!cppc_req_cached) {
 			epp = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
 					&cppc_req_cached);
@@ -247,12 +239,32 @@ static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata)
 	return index;
 }
 
+static void pstate_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
+			       u32 des_perf, u32 max_perf, bool fast_switch)
+{
+	if (fast_switch)
+		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
+	else
+		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
+			      READ_ONCE(cpudata->cppc_req_cached));
+}
+
+DEFINE_STATIC_CALL(amd_pstate_update_perf, pstate_update_perf);
+
+static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata,
+					  u32 min_perf, u32 des_perf,
+					  u32 max_perf, bool fast_switch)
+{
+	static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
+					    max_perf, fast_switch);
+}
+
 static int amd_pstate_set_epp(struct amd_cpudata *cpudata, u32 epp)
 {
 	int ret;
 	struct cppc_perf_ctrls perf_ctrls;
 
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		u64 value = READ_ONCE(cpudata->cppc_req_cached);
 
 		value &= ~GENMASK_ULL(31, 24);
@@ -263,6 +275,9 @@ static int amd_pstate_set_epp(struct amd_cpudata *cpudata, u32 epp)
 		if (!ret)
 			cpudata->epp_cached = epp;
 	} else {
+		amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
+					     cpudata->max_limit_perf, false);
+
 		perf_ctrls.energy_perf = epp;
 		ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1);
 		if (ret) {
@@ -281,10 +296,8 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
 	int epp = -EINVAL;
 	int ret;
 
-	if (!pref_index) {
-		pr_debug("EPP pref_index is invalid\n");
-		return -EINVAL;
-	}
+	if (!pref_index)
+		epp = cpudata->epp_default;
 
 	if (epp == -EINVAL)
 		epp = epp_values[pref_index];
@@ -452,16 +465,6 @@ static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata)
 	return static_call(amd_pstate_init_perf)(cpudata);
 }
 
-static void pstate_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
-			       u32 des_perf, u32 max_perf, bool fast_switch)
-{
-	if (fast_switch)
-		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
-	else
-		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
-			      READ_ONCE(cpudata->cppc_req_cached));
-}
-
 static void cppc_update_perf(struct amd_cpudata *cpudata,
 			     u32 min_perf, u32 des_perf,
 			     u32 max_perf, bool fast_switch)
@@ -475,16 +478,6 @@ static void cppc_update_perf(struct amd_cpudata *cpudata,
 	cppc_set_perf(cpudata->cpu, &perf_ctrls);
 }
 
-DEFINE_STATIC_CALL(amd_pstate_update_perf, pstate_update_perf);
-
-static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata,
-					  u32 min_perf, u32 des_perf,
-					  u32 max_perf, bool fast_switch)
-{
-	static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
-					    max_perf, fast_switch);
-}
-
 static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
 {
 	u64 aperf, mperf, tsc;
@@ -521,7 +514,10 @@ static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
 static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 			      u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags)
 {
+	unsigned long max_freq;
+	struct cpufreq_policy *policy = cpufreq_cpu_get(cpudata->cpu);
 	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
+	u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	u64 value = prev;
 
 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
@@ -530,6 +526,9 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 			cpudata->max_limit_perf);
 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
 
+	max_freq = READ_ONCE(cpudata->max_limit_freq);
+	policy->cur = div_u64(des_perf * max_freq, max_perf);
+
 	if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) {
 		min_perf = des_perf;
 		des_perf = 0;
@@ -541,6 +540,10 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 	value &= ~AMD_CPPC_DES_PERF(~0L);
 	value |= AMD_CPPC_DES_PERF(des_perf);
 
+	/* limit the max perf when core performance boost feature is disabled */
+	if (!cpudata->boost_supported)
+		max_perf = min_t(unsigned long, nominal_perf, max_perf);
+
 	value &= ~AMD_CPPC_MAX_PERF(~0L);
 	value |= AMD_CPPC_MAX_PERF(max_perf);
 
@@ -651,10 +654,9 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 				   unsigned long capacity)
 {
 	unsigned long max_perf, min_perf, des_perf,
-		      cap_perf, lowest_nonlinear_perf, max_freq;
+		      cap_perf, lowest_nonlinear_perf;
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 	struct amd_cpudata *cpudata = policy->driver_data;
-	unsigned int target_freq;
 
 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
 		amd_pstate_update_min_max_limit(policy);
@@ -662,7 +664,6 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 
 	cap_perf = READ_ONCE(cpudata->highest_perf);
 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
-	max_freq = READ_ONCE(cpudata->max_freq);
 
 	des_perf = cap_perf;
 	if (target_perf < capacity)
@@ -680,51 +681,111 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 		max_perf = min_perf;
 
 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
-	target_freq = div_u64(des_perf * max_freq, max_perf);
-	policy->cur = target_freq;
 
 	amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
 			policy->governor->flags);
 	cpufreq_cpu_put(policy);
 }
 
-static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
+static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
+	struct cppc_perf_ctrls perf_ctrls;
+	u32 highest_perf, nominal_perf, nominal_freq, max_freq;
 	int ret;
 
-	if (!cpudata->boost_supported) {
-		pr_err("Boost mode is not supported by this processor or SBIOS\n");
-		return -EINVAL;
+	highest_perf = READ_ONCE(cpudata->highest_perf);
+	nominal_perf = READ_ONCE(cpudata->nominal_perf);
+	nominal_freq = READ_ONCE(cpudata->nominal_freq);
+	max_freq = READ_ONCE(cpudata->max_freq);
+
+	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+		u64 value = READ_ONCE(cpudata->cppc_req_cached);
+
+		value &= ~GENMASK_ULL(7, 0);
+		value |= on ? highest_perf : nominal_perf;
+		WRITE_ONCE(cpudata->cppc_req_cached, value);
+
+		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
+	} else {
+		perf_ctrls.max_perf = on ? highest_perf : nominal_perf;
+		ret = cppc_set_perf(cpudata->cpu, &perf_ctrls);
+		if (ret) {
+			cpufreq_cpu_release(policy);
+			pr_debug("Failed to set max perf on CPU:%d. ret:%d\n",
+				cpudata->cpu, ret);
+			return ret;
+		}
 	}
 
-	if (state)
-		policy->cpuinfo.max_freq = cpudata->max_freq;
-	else
-		policy->cpuinfo.max_freq = cpudata->nominal_freq * 1000;
+	if (on)
+		policy->cpuinfo.max_freq = max_freq;
+	else if (policy->cpuinfo.max_freq > nominal_freq * 1000)
+		policy->cpuinfo.max_freq = nominal_freq * 1000;
 
 	policy->max = policy->cpuinfo.max_freq;
 
-	ret = freq_qos_update_request(&cpudata->req[1],
-				      policy->cpuinfo.max_freq);
-	if (ret < 0)
-		return ret;
+	if (cppc_state == AMD_PSTATE_PASSIVE) {
+		ret = freq_qos_update_request(&cpudata->req[1], policy->cpuinfo.max_freq);
+		if (ret < 0)
+			pr_debug("Failed to update freq constraint: CPU%d\n", cpudata->cpu);
+	}
 
-	return 0;
+	return ret < 0 ? ret : 0;
 }
 
-static void amd_pstate_boost_init(struct amd_cpudata *cpudata)
+static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
 {
-	u32 highest_perf, nominal_perf;
+	struct amd_cpudata *cpudata = policy->driver_data;
+	int ret;
 
-	highest_perf = READ_ONCE(cpudata->highest_perf);
-	nominal_perf = READ_ONCE(cpudata->nominal_perf);
+	if (!cpudata->boost_supported) {
+		pr_err("Boost mode is not supported by this processor or SBIOS\n");
+		return -EOPNOTSUPP;
+	}
+	mutex_lock(&amd_pstate_driver_lock);
+	ret = amd_pstate_cpu_boost_update(policy, state);
+	WRITE_ONCE(cpudata->boost_state, !ret ? state : false);
+	policy->boost_enabled = !ret ? state : false;
+	refresh_frequency_limits(policy);
+	mutex_unlock(&amd_pstate_driver_lock);
 
-	if (highest_perf <= nominal_perf)
-		return;
+	return ret;
+}
 
-	cpudata->boost_supported = true;
+static int amd_pstate_init_boost_support(struct amd_cpudata *cpudata)
+{
+	u64 boost_val;
+	int ret = -1;
+
+	/*
+	 * If platform has no CPB support or disable it, initialize current driver
+	 * boost_enabled state to be false, it is not an error for cpufreq core to handle.
+	 */
+	if (!cpu_feature_enabled(X86_FEATURE_CPB)) {
+		pr_debug_once("Boost CPB capabilities not present in the processor\n");
+		ret = 0;
+		goto exit_err;
+	}
+
+	/* at least one CPU supports CPB, even if others fail later on to set up */
 	current_pstate_driver->boost_enabled = true;
+
+	ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
+	if (ret) {
+		pr_err_once("failed to read initial CPU boost state!\n");
+		ret = -EIO;
+		goto exit_err;
+	}
+
+	if (!(boost_val & MSR_K7_HWCR_CPB_DIS))
+		cpudata->boost_supported = true;
+
+	return 0;
+
+exit_err:
+	cpudata->boost_supported = false;
+	return ret;
 }
 
 static void amd_perf_ctl_reset(unsigned int cpu)
@@ -753,7 +814,7 @@ static int amd_pstate_get_highest_perf(int cpu, u32 *highest_perf)
 {
 	int ret;
 
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		u64 cap1;
 
 		ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
@@ -849,8 +910,12 @@ static u32 amd_pstate_get_transition_delay_us(unsigned int cpu)
 	u32 transition_delay_ns;
 
 	transition_delay_ns = cppc_get_transition_latency(cpu);
-	if (transition_delay_ns == CPUFREQ_ETERNAL)
-		return AMD_PSTATE_TRANSITION_DELAY;
+	if (transition_delay_ns == CPUFREQ_ETERNAL) {
+		if (cpu_feature_enabled(X86_FEATURE_FAST_CPPC))
+			return AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY;
+		else
+			return AMD_PSTATE_TRANSITION_DELAY;
+	}
 
 	return transition_delay_ns / NSEC_PER_USEC;
 }
@@ -921,12 +986,30 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 	WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
 	WRITE_ONCE(cpudata->max_freq, max_freq);
 
+	/**
+	 * Below values need to be initialized correctly, otherwise driver will fail to load
+	 * max_freq is calculated according to (nominal_freq * highest_perf)/nominal_perf
+	 * lowest_nonlinear_freq is a value between [min_freq, nominal_freq]
+	 * Check _CPC in ACPI table objects if any values are incorrect
+	 */
+	if (min_freq <= 0 || max_freq <= 0 || nominal_freq <= 0 || min_freq > max_freq) {
+		pr_err("min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect\n",
+			min_freq, max_freq, nominal_freq * 1000);
+		return -EINVAL;
+	}
+
+	if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq * 1000) {
+		pr_err("lowest_nonlinear_freq(%d) value is out of range [min_freq(%d), nominal_freq(%d)]\n",
+			lowest_nonlinear_freq, min_freq, nominal_freq * 1000);
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 {
-	int min_freq, max_freq, nominal_freq, ret;
+	int min_freq, max_freq, ret;
 	struct device *dev;
 	struct amd_cpudata *cpudata;
 
@@ -955,18 +1038,12 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
+	ret = amd_pstate_init_boost_support(cpudata);
+	if (ret)
+		goto free_cpudata1;
+
 	min_freq = READ_ONCE(cpudata->min_freq);
 	max_freq = READ_ONCE(cpudata->max_freq);
-	nominal_freq = READ_ONCE(cpudata->nominal_freq);
-
-	if (min_freq <= 0 || max_freq <= 0 ||
-	    nominal_freq <= 0 || min_freq > max_freq) {
-		dev_err(dev,
-			"min_freq(%d) or max_freq(%d) or nominal_freq (%d) value is incorrect, check _CPC in ACPI tables\n",
-			min_freq, max_freq, nominal_freq);
-		ret = -EINVAL;
-		goto free_cpudata1;
-	}
 
 	policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu);
 	policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu);
@@ -977,10 +1054,12 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	policy->cpuinfo.min_freq = min_freq;
 	policy->cpuinfo.max_freq = max_freq;
 
+	policy->boost_enabled = READ_ONCE(cpudata->boost_supported);
+
 	/* It will be updated by governor */
 	policy->cur = policy->cpuinfo.min_freq;
 
-	if (boot_cpu_has(X86_FEATURE_CPPC))
+	if (cpu_feature_enabled(X86_FEATURE_CPPC))
 		policy->fast_switch_possible = true;
 
 	ret = freq_qos_add_request(&policy->constraints, &cpudata->req[0],
@@ -1002,7 +1081,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 
 	policy->driver_data = cpudata;
 
-	amd_pstate_boost_init(cpudata);
 	if (!current_pstate_driver->adjust_perf)
 		current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
 
@@ -1015,7 +1093,7 @@ free_cpudata1:
 	return ret;
 }
 
-static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
+static void amd_pstate_cpu_exit(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 
@@ -1023,8 +1101,6 @@ static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
 	freq_qos_remove_request(&cpudata->req[0]);
 	policy->fast_switch_possible = false;
 	kfree(cpudata);
-
-	return 0;
 }
 
 static int amd_pstate_cpu_resume(struct cpufreq_policy *policy)
@@ -1213,7 +1289,7 @@ static int amd_pstate_change_mode_without_dvr_change(int mode)
 
 	cppc_state = mode;
 
-	if (boot_cpu_has(X86_FEATURE_CPPC) || cppc_state == AMD_PSTATE_ACTIVE)
+	if (cpu_feature_enabled(X86_FEATURE_CPPC) || cppc_state == AMD_PSTATE_ACTIVE)
 		return 0;
 
 	for_each_present_cpu(cpu) {
@@ -1386,7 +1462,7 @@ static bool amd_pstate_acpi_pm_profile_undefined(void)
 
 static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 {
-	int min_freq, max_freq, nominal_freq, ret;
+	int min_freq, max_freq, ret;
 	struct amd_cpudata *cpudata;
 	struct device *dev;
 	u64 value;
@@ -1417,17 +1493,12 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
+	ret = amd_pstate_init_boost_support(cpudata);
+	if (ret)
+		goto free_cpudata1;
+
 	min_freq = READ_ONCE(cpudata->min_freq);
 	max_freq = READ_ONCE(cpudata->max_freq);
-	nominal_freq = READ_ONCE(cpudata->nominal_freq);
-	if (min_freq <= 0 || max_freq <= 0 ||
-	    nominal_freq <= 0 || min_freq > max_freq) {
-		dev_err(dev,
-			"min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect, check _CPC in ACPI tables\n",
-			min_freq, max_freq, nominal_freq);
-		ret = -EINVAL;
-		goto free_cpudata1;
-	}
 
 	policy->cpuinfo.min_freq = min_freq;
 	policy->cpuinfo.max_freq = max_freq;
@@ -1436,11 +1507,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 
 	policy->driver_data = cpudata;
 
-	cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0);
+	cpudata->epp_cached = cpudata->epp_default = amd_pstate_get_epp(cpudata, 0);
 
 	policy->min = policy->cpuinfo.min_freq;
 	policy->max = policy->cpuinfo.max_freq;
 
+	policy->boost_enabled = READ_ONCE(cpudata->boost_supported);
+
 	/*
 	 * Set the policy to provide a valid fallback value in case
 	 * the default cpufreq governor is neither powersave nor performance.
@@ -1451,7 +1524,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	else
 		policy->policy = CPUFREQ_POLICY_POWERSAVE;
 
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
 		if (ret)
 			return ret;
@@ -1462,7 +1535,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 			return ret;
 		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
 	}
-	amd_pstate_boost_init(cpudata);
 
 	return 0;
 
@@ -1471,7 +1543,7 @@ free_cpudata1:
 	return ret;
 }
 
-static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
+static void amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 
@@ -1481,7 +1553,6 @@ static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
 	}
 
 	pr_debug("CPU %d exiting\n", policy->cpu);
-	return 0;
 }
 
 static void amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
@@ -1541,7 +1612,7 @@ static void amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 		epp = 0;
 
 	/* Set initial EPP value */
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		value &= ~GENMASK_ULL(31, 24);
 		value |= (u64)epp << 24;
 	}
@@ -1564,6 +1635,12 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
 
 	amd_pstate_epp_update_limit(policy);
 
+	/*
+	 * policy->cur is never updated with the amd_pstate_epp driver, but it
+	 * is used as a stale frequency value. So, keep it within limits.
+	 */
+	policy->cur = policy->min;
+
 	return 0;
 }
 
@@ -1580,7 +1657,7 @@ static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
 	value = READ_ONCE(cpudata->cppc_req_cached);
 	max_perf = READ_ONCE(cpudata->highest_perf);
 
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
 	} else {
 		perf_ctrls.max_perf = max_perf;
@@ -1614,7 +1691,7 @@ static void amd_pstate_epp_offline(struct cpufreq_policy *policy)
 	value = READ_ONCE(cpudata->cppc_req_cached);
 
 	mutex_lock(&amd_pstate_limits_lock);
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		cpudata->epp_policy = CPUFREQ_POLICY_UNKNOWN;
 
 		/* Set max perf same as min perf */
@@ -1718,6 +1795,7 @@ static struct cpufreq_driver amd_pstate_epp_driver = {
 	.suspend	= amd_pstate_epp_suspend,
 	.resume		= amd_pstate_epp_resume,
 	.update_limits	= amd_pstate_update_limits,
+	.set_boost	= amd_pstate_set_boost,
 	.name		= "amd-pstate-epp",
 	.attr		= amd_pstate_epp_attr,
 };
@@ -1741,6 +1819,46 @@ static int __init amd_pstate_set_driver(int mode_idx)
 	return -EINVAL;
 }
 
+/**
+ * CPPC function is not supported for family ID 17H with model_ID ranging from 0x10 to 0x2F.
+ * show the debug message that helps to check if the CPU has CPPC support for loading issue.
+ */
+static bool amd_cppc_supported(void)
+{
+	struct cpuinfo_x86 *c = &cpu_data(0);
+	bool warn = false;
+
+	if ((boot_cpu_data.x86 == 0x17) && (boot_cpu_data.x86_model < 0x30)) {
+		pr_debug_once("CPPC feature is not supported by the processor\n");
+		return false;
+	}
+
+	/*
+	 * If the CPPC feature is disabled in the BIOS for processors that support MSR-based CPPC,
+	 * the AMD Pstate driver may not function correctly.
+	 * Check the CPPC flag and display a warning message if the platform supports CPPC.
+	 * Note: below checking code will not abort the driver registeration process because of
+	 * the code is added for debugging purposes.
+	 */
+	if (!cpu_feature_enabled(X86_FEATURE_CPPC)) {
+		if (cpu_feature_enabled(X86_FEATURE_ZEN1) || cpu_feature_enabled(X86_FEATURE_ZEN2)) {
+			if (c->x86_model > 0x60 && c->x86_model < 0xaf)
+				warn = true;
+		} else if (cpu_feature_enabled(X86_FEATURE_ZEN3) || cpu_feature_enabled(X86_FEATURE_ZEN4)) {
+			if ((c->x86_model > 0x10 && c->x86_model < 0x1F) ||
+					(c->x86_model > 0x40 && c->x86_model < 0xaf))
+				warn = true;
+		} else if (cpu_feature_enabled(X86_FEATURE_ZEN5)) {
+			warn = true;
+		}
+	}
+
+	if (warn)
+		pr_warn_once("The CPPC feature is supported but currently disabled by the BIOS.\n"
+					"Please enable it if your BIOS has the CPPC option.\n");
+	return true;
+}
+
 static int __init amd_pstate_init(void)
 {
 	struct device *dev_root;
@@ -1749,6 +1867,11 @@ static int __init amd_pstate_init(void)
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
 		return -ENODEV;
 
+	/* show debug message only if CPPC is not supported */
+	if (!amd_cppc_supported())
+		return -EOPNOTSUPP;
+
+	/* show warning message when BIOS broken or ACPI disabled */
 	if (!acpi_cpc_valid()) {
 		pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n");
 		return -ENODEV;
@@ -1763,35 +1886,43 @@ static int __init amd_pstate_init(void)
 	/* check if this machine need CPPC quirks */
 	dmi_check_system(amd_pstate_quirks_table);
 
-	switch (cppc_state) {
-	case AMD_PSTATE_UNDEFINED:
+	/*
+	* determine the driver mode from the command line or kernel config.
+	* If no command line input is provided, cppc_state will be AMD_PSTATE_UNDEFINED.
+	* command line options will override the kernel config settings.
+	*/
+
+	if (cppc_state == AMD_PSTATE_UNDEFINED) {
 		/* Disable on the following configs by default:
 		 * 1. Undefined platforms
 		 * 2. Server platforms
-		 * 3. Shared memory designs
 		 */
 		if (amd_pstate_acpi_pm_profile_undefined() ||
-		    amd_pstate_acpi_pm_profile_server() ||
-		    !boot_cpu_has(X86_FEATURE_CPPC)) {
+		    amd_pstate_acpi_pm_profile_server()) {
 			pr_info("driver load is disabled, boot with specific mode to enable this\n");
 			return -ENODEV;
 		}
-		ret = amd_pstate_set_driver(CONFIG_X86_AMD_PSTATE_DEFAULT_MODE);
-		if (ret)
-			return ret;
-		break;
+		/* get driver mode from kernel config option [1:4] */
+		cppc_state = CONFIG_X86_AMD_PSTATE_DEFAULT_MODE;
+	}
+
+	switch (cppc_state) {
 	case AMD_PSTATE_DISABLE:
+		pr_info("driver load is disabled, boot with specific mode to enable this\n");
 		return -ENODEV;
 	case AMD_PSTATE_PASSIVE:
 	case AMD_PSTATE_ACTIVE:
 	case AMD_PSTATE_GUIDED:
+		ret = amd_pstate_set_driver(cppc_state);
+		if (ret)
+			return ret;
 		break;
 	default:
 		return -EINVAL;
 	}
 
 	/* capability check */
-	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		pr_debug("AMD CPPC MSR based functionality is supported\n");
 		if (cppc_state != AMD_PSTATE_ACTIVE)
 			current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
@@ -1805,13 +1936,15 @@ static int __init amd_pstate_init(void)
 	/* enable amd pstate feature */
 	ret = amd_pstate_enable(true);
 	if (ret) {
-		pr_err("failed to enable with return %d\n", ret);
+		pr_err("failed to enable driver mode(%d)\n", cppc_state);
 		return ret;
 	}
 
 	ret = cpufreq_register_driver(current_pstate_driver);
-	if (ret)
+	if (ret) {
 		pr_err("failed to register with return %d\n", ret);
+		goto disable_driver;
+	}
 
 	dev_root = bus_get_dev_root(&cpu_subsys);
 	if (dev_root) {
@@ -1827,6 +1960,8 @@ static int __init amd_pstate_init(void)
 
 global_attr_free:
 	cpufreq_unregister_driver(current_pstate_driver);
+disable_driver:
+	amd_pstate_enable(false);
 	return ret;
 }
 device_initcall(amd_pstate_init);