[PATCH v2 00/17] amd-pstate cleanups

[PATCH v2 00/17] amd-pstate cleanups

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

This series overhauls locking and drops many unnecessarily cached
variables.

Debugging messages are also dropped in favor of more ftracing.

This series is based off superm1/linux.git bleeding-edge branch.

Mario Limonciello (17):
  cpufreq/amd-pstate: Show a warning when a CPU fails to setup
  cpufreq/amd-pstate: Drop min and max cached frequencies
  cpufreq/amd-pstate: Move perf values into a union
  cpufreq/amd-pstate: Overhaul locking
  cpufreq/amd-pstate: Drop `cppc_cap1_cached`
  cpufreq/amd-pstate-ut: Use _free macro to free put policy
  cpufreq/amd-pstate-ut: Allow lowest nonlinear and lowest to be the
    same
  cpufreq/amd-pstate-ut: Drop SUCCESS and FAIL enums
  cpufreq/amd-pstate-ut: Continue on missing policies
  cpufreq/amd-pstate-ut: Adjust variable scope for
    amd_pstate_ut_check_freq()
  cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks
  cpufreq/amd-pstate: Cache CPPC request in shared mem case too
  cpufreq/amd-pstate: Move all EPP tracing into *_update_perf and
    *_set_epp functions
  cpufreq/amd-pstate: Update cppc_req_cached for shared mem EPP writes
  cpufreq/amd-pstate: Drop debug statements for policy setting
  cpufreq/amd-pstate: Rework CPPC enabling
  cpufreq/amd-pstate: Stop caching EPP

 arch/x86/include/asm/msr-index.h   |  20 +-
 arch/x86/kernel/acpi/cppc.c        |   2 +-
 drivers/cpufreq/amd-pstate-trace.h |  13 +-
 drivers/cpufreq/amd-pstate-ut.c    | 204 ++++------
 drivers/cpufreq/amd-pstate.c       | 589 ++++++++++++++---------------
 drivers/cpufreq/amd-pstate.h       |  60 +--
 6 files changed, 414 insertions(+), 474 deletions(-)

-- 
2.43.0

[PATCH v2 01/17] cpufreq/amd-pstate: Show a warning when a CPU fails to setup

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

I came across a system that MSR_AMD_CPPC_CAP1 for some CPUs isn't
populated.  This is an unexpected behavior that is most likely a
BIOS bug. In the event it happens I'd like users to report bugs
to properly root cause and get this fixed.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index f425fb7ec77d7..573643654e8d6 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1034,6 +1034,7 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 free_cpudata2:
 	freq_qos_remove_request(&cpudata->req[0]);
 free_cpudata1:
+	pr_warn("Failed to initialize CPU %d: %d\n", policy->cpu, ret);
 	kfree(cpudata);
 	return ret;
 }
@@ -1527,6 +1528,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	return 0;
 
 free_cpudata1:
+	pr_warn("Failed to initialize CPU %d: %d\n", policy->cpu, ret);
 	kfree(cpudata);
 	return ret;
 }
-- 
2.43.0

Re: [PATCH v2 01/17] cpufreq/amd-pstate: Show a warning when a CPU fails to setup

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:28PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> I came across a system that MSR_AMD_CPPC_CAP1 for some CPUs isn't
> populated.  This is an unexpected behavior that is most likely a
> BIOS bug. In the event it happens I'd like users to report bugs
> to properly root cause and get this fixed.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.

> ---
>  drivers/cpufreq/amd-pstate.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index f425fb7ec77d7..573643654e8d6 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1034,6 +1034,7 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
>  free_cpudata2:
>  	freq_qos_remove_request(&cpudata->req[0]);
>  free_cpudata1:
> +	pr_warn("Failed to initialize CPU %d: %d\n", policy->cpu, ret);
>  	kfree(cpudata);
>  	return ret;
>  }
> @@ -1527,6 +1528,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  	return 0;
>  
>  free_cpudata1:
> +	pr_warn("Failed to initialize CPU %d: %d\n", policy->cpu, ret);
>  	kfree(cpudata);
>  	return ret;
>  }
> -- 
> 2.43.0
> 

[PATCH v2 02/17] cpufreq/amd-pstate: Drop min and max cached frequencies

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

Use the perf_to_freq helpers to calculate this on the fly.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
--
v2:
 * Keep cached limits
---
 drivers/cpufreq/amd-pstate-ut.c | 14 +++----
 drivers/cpufreq/amd-pstate.c    | 69 +++++++++++----------------------
 drivers/cpufreq/amd-pstate.h    |  9 +----
 3 files changed, 31 insertions(+), 61 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index 3a0a380c3590c..445278cf40b61 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -214,14 +214,14 @@ static void amd_pstate_ut_check_freq(u32 index)
 			break;
 		cpudata = policy->driver_data;
 
-		if (!((cpudata->max_freq >= cpudata->nominal_freq) &&
+		if (!((policy->cpuinfo.max_freq >= cpudata->nominal_freq) &&
 			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
-			(cpudata->lowest_nonlinear_freq > cpudata->min_freq) &&
-			(cpudata->min_freq > 0))) {
+			(cpudata->lowest_nonlinear_freq > policy->cpuinfo.min_freq) &&
+			(policy->cpuinfo.min_freq > 0))) {
 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
-				__func__, cpu, cpudata->max_freq, cpudata->nominal_freq,
-				cpudata->lowest_nonlinear_freq, cpudata->min_freq);
+				__func__, cpu, policy->cpuinfo.max_freq, cpudata->nominal_freq,
+				cpudata->lowest_nonlinear_freq, policy->cpuinfo.min_freq);
 			goto skip_test;
 		}
 
@@ -233,13 +233,13 @@ static void amd_pstate_ut_check_freq(u32 index)
 		}
 
 		if (cpudata->boost_supported) {
-			if ((policy->max == cpudata->max_freq) ||
+			if ((policy->max == policy->cpuinfo.max_freq) ||
 					(policy->max == cpudata->nominal_freq))
 				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
 			else {
 				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
-					__func__, cpu, policy->max, cpudata->max_freq,
+					__func__, cpu, policy->max, policy->cpuinfo.max_freq,
 					cpudata->nominal_freq);
 				goto skip_test;
 			}
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 573643654e8d6..bcebdc4167fe0 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -717,7 +717,7 @@ static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
 	int ret = 0;
 
 	nominal_freq = READ_ONCE(cpudata->nominal_freq);
-	max_freq = READ_ONCE(cpudata->max_freq);
+	max_freq = perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf));
 
 	if (on)
 		policy->cpuinfo.max_freq = max_freq;
@@ -901,35 +901,25 @@ static u32 amd_pstate_get_transition_latency(unsigned int cpu)
 static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 {
 	int ret;
-	u32 min_freq, max_freq;
-	u32 nominal_freq, lowest_nonlinear_freq;
+	u32 min_freq, nominal_freq, lowest_nonlinear_freq;
 	struct cppc_perf_caps cppc_perf;
 
 	ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
 	if (ret)
 		return ret;
 
-	if (quirks && quirks->lowest_freq)
-		min_freq = quirks->lowest_freq;
-	else
-		min_freq = cppc_perf.lowest_freq;
-
 	if (quirks && quirks->nominal_freq)
 		nominal_freq = quirks->nominal_freq;
 	else
 		nominal_freq = cppc_perf.nominal_freq;
 
-	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);
 
-	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
-	WRITE_ONCE(cpudata->max_freq, max_freq);
+	if (quirks && quirks->lowest_freq) {
+		min_freq = quirks->lowest_freq;
+	} else
+		min_freq = cppc_perf.lowest_freq;
 
 	/**
 	 * Below values need to be initialized correctly, otherwise driver will fail to load
@@ -937,12 +927,15 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 	 * 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);
+	if (nominal_freq <= 0) {
+		pr_err("nominal_freq(%d) value is incorrect\n",
+			nominal_freq);
 		return -EINVAL;
 	}
 
+	lowest_nonlinear_freq = perf_to_freq(cpudata, cpudata->lowest_nonlinear_perf);
+	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
+
 	if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq) {
 		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);
@@ -954,9 +947,9 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 
 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 {
-	int min_freq, max_freq, ret;
-	struct device *dev;
 	struct amd_cpudata *cpudata;
+	struct device *dev;
+	int ret;
 
 	/*
 	 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency,
@@ -987,17 +980,11 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
-	min_freq = READ_ONCE(cpudata->min_freq);
-	max_freq = READ_ONCE(cpudata->max_freq);
-
 	policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu);
 	policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu);
 
-	policy->min = min_freq;
-	policy->max = max_freq;
-
-	policy->cpuinfo.min_freq = min_freq;
-	policy->cpuinfo.max_freq = max_freq;
+	policy->cpuinfo.min_freq = policy->min = perf_to_freq(cpudata, cpudata->lowest_perf);
+	policy->cpuinfo.max_freq = policy->max = perf_to_freq(cpudata, cpudata->highest_perf);
 
 	policy->boost_enabled = READ_ONCE(cpudata->boost_supported);
 
@@ -1021,9 +1008,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 		goto free_cpudata2;
 	}
 
-	cpudata->max_limit_freq = max_freq;
-	cpudata->min_limit_freq = min_freq;
-
 	policy->driver_data = cpudata;
 
 	if (!current_pstate_driver->adjust_perf)
@@ -1081,14 +1065,10 @@ static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
 static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy,
 					char *buf)
 {
-	int max_freq;
 	struct amd_cpudata *cpudata = policy->driver_data;
 
-	max_freq = READ_ONCE(cpudata->max_freq);
-	if (max_freq < 0)
-		return max_freq;
 
-	return sysfs_emit(buf, "%u\n", max_freq);
+	return sysfs_emit(buf, "%u\n", perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf)));
 }
 
 static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy,
@@ -1446,10 +1426,10 @@ 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, ret;
 	struct amd_cpudata *cpudata;
 	struct device *dev;
 	u64 value;
+	int ret;
 
 	/*
 	 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency,
@@ -1480,19 +1460,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
-	min_freq = READ_ONCE(cpudata->min_freq);
-	max_freq = READ_ONCE(cpudata->max_freq);
-
-	policy->cpuinfo.min_freq = min_freq;
-	policy->cpuinfo.max_freq = max_freq;
+	policy->cpuinfo.min_freq = policy->min = perf_to_freq(cpudata, cpudata->lowest_perf);
+	policy->cpuinfo.max_freq = policy->max = perf_to_freq(cpudata, cpudata->highest_perf);
 	/* It will be updated by governor */
 	policy->cur = policy->cpuinfo.min_freq;
 
 	policy->driver_data = cpudata;
 
-	policy->min = policy->cpuinfo.min_freq;
-	policy->max = policy->cpuinfo.max_freq;
-
 	policy->boost_enabled = READ_ONCE(cpudata->boost_supported);
 
 	/*
@@ -1550,7 +1524,8 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	struct amd_cpudata *cpudata = policy->driver_data;
 	u8 epp;
 
-	amd_pstate_update_min_max_limit(policy);
+	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
+		amd_pstate_update_min_max_limit(policy);
 
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
 		epp = 0;
diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
index 19d405c6d805e..0149933692458 100644
--- a/drivers/cpufreq/amd-pstate.h
+++ b/drivers/cpufreq/amd-pstate.h
@@ -46,8 +46,6 @@ struct amd_aperf_mperf {
  * @max_limit_perf: Cached value of the performance corresponding to policy->max
  * @min_limit_freq: Cached value of policy->min (in khz)
  * @max_limit_freq: Cached value of policy->max (in khz)
- * @max_freq: the frequency (in khz) that mapped to highest_perf
- * @min_freq: the frequency (in khz) that mapped to lowest_perf
  * @nominal_freq: the frequency (in khz) that mapped to nominal_perf
  * @lowest_nonlinear_freq: the frequency (in khz) that mapped to lowest_nonlinear_perf
  * @cur: Difference of Aperf/Mperf/tsc count between last and current sample
@@ -77,11 +75,8 @@ struct amd_cpudata {
 	u8	prefcore_ranking;
 	u8	min_limit_perf;
 	u8	max_limit_perf;
-	u32     min_limit_freq;
-	u32     max_limit_freq;
-
-	u32	max_freq;
-	u32	min_freq;
+	u32	min_limit_freq;
+	u32	max_limit_freq;
 	u32	nominal_freq;
 	u32	lowest_nonlinear_freq;
 
-- 
2.43.0

Re: [PATCH v2 02/17] cpufreq/amd-pstate: Drop min and max cached frequencies

[Gautham R. Shenoy]

Hello Mario,

On Fri, Feb 14, 2025 at 06:52:29PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> Use the perf_to_freq helpers to calculate this on the fly.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> --
> v2:
>  * Keep cached limits
> ---

[..snip..]

> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -717,7 +717,7 @@ static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
>  	int ret = 0;
>  
>  	nominal_freq = READ_ONCE(cpudata->nominal_freq);
> -	max_freq = READ_ONCE(cpudata->max_freq);
> +	max_freq = perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf));
>  
>  	if (on)
>  		policy->cpuinfo.max_freq = max_freq;
> @@ -901,35 +901,25 @@ static u32 amd_pstate_get_transition_latency(unsigned int cpu)
>  static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>  {
>  	int ret;
> -	u32 min_freq, max_freq;
> -	u32 nominal_freq, lowest_nonlinear_freq;
> +	u32 min_freq, nominal_freq, lowest_nonlinear_freq;
>  	struct cppc_perf_caps cppc_perf;
>  
>  	ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
>  	if (ret)
>  		return ret;
>  
> -	if (quirks && quirks->lowest_freq)
> -		min_freq = quirks->lowest_freq;
> -	else
> -		min_freq = cppc_perf.lowest_freq;
> -
>  	if (quirks && quirks->nominal_freq)
>  		nominal_freq = quirks->nominal_freq;
>  	else
>  		nominal_freq = cppc_perf.nominal_freq;
>  
> -	min_freq *= 1000;
>  	nominal_freq *= 1000;
> -
>  	WRITE_ONCE(cpudata->nominal_freq, nominal_freq);

So cpudata->nominal_freq will be in KHz here.


> -	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);
>  
> -	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
> -	WRITE_ONCE(cpudata->max_freq, max_freq);
> +	if (quirks && quirks->lowest_freq) {
> +		min_freq = quirks->lowest_freq;
> +	} else
> +		min_freq = cppc_perf.lowest_freq;
>

Since cppc_perf exposes the frequency values in MHz, min_freq is in MHz.

>  	/**
>  	 * Below values need to be initialized correctly, otherwise driver will fail to load
> @@ -937,12 +927,15 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>  	 * 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);
> +	if (nominal_freq <= 0) {
> +		pr_err("nominal_freq(%d) value is incorrect\n",
> +			nominal_freq);
>  		return -EINVAL;
>  	}
>  
> +	lowest_nonlinear_freq = perf_to_freq(cpudata, cpudata->lowest_nonlinear_perf);

Since lowest_nonlinear_freq will be computed using cpudata->nominal_freq, the former will be in KHz.

> +	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
> +
>  	if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq) {
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

And thus since lowest_nonlinear_freq is in KHz and min_freq is in MHz, this check will always be true.

Shouldn't the min_freq be multiplied by 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);


-- 
Thanks and Regards
gautham.

Re: [PATCH v2 02/17] cpufreq/amd-pstate: Drop min and max cached frequencies

[Mario Limonciello]

On 2/17/2025 00:38, Gautham R. Shenoy wrote:
> Hello Mario,
> 
> On Fri, Feb 14, 2025 at 06:52:29PM -0600, Mario Limonciello wrote:
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> Use the perf_to_freq helpers to calculate this on the fly.
>>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> --
>> v2:
>>   * Keep cached limits
>> ---
> 
> [..snip..]
> 
>> --- a/drivers/cpufreq/amd-pstate.c
>> +++ b/drivers/cpufreq/amd-pstate.c
>> @@ -717,7 +717,7 @@ static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
>>   	int ret = 0;
>>   
>>   	nominal_freq = READ_ONCE(cpudata->nominal_freq);
>> -	max_freq = READ_ONCE(cpudata->max_freq);
>> +	max_freq = perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf));
>>   
>>   	if (on)
>>   		policy->cpuinfo.max_freq = max_freq;
>> @@ -901,35 +901,25 @@ static u32 amd_pstate_get_transition_latency(unsigned int cpu)
>>   static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>>   {
>>   	int ret;
>> -	u32 min_freq, max_freq;
>> -	u32 nominal_freq, lowest_nonlinear_freq;
>> +	u32 min_freq, nominal_freq, lowest_nonlinear_freq;
>>   	struct cppc_perf_caps cppc_perf;
>>   
>>   	ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
>>   	if (ret)
>>   		return ret;
>>   
>> -	if (quirks && quirks->lowest_freq)
>> -		min_freq = quirks->lowest_freq;
>> -	else
>> -		min_freq = cppc_perf.lowest_freq;
>> -
>>   	if (quirks && quirks->nominal_freq)
>>   		nominal_freq = quirks->nominal_freq;
>>   	else
>>   		nominal_freq = cppc_perf.nominal_freq;
>>   
>> -	min_freq *= 1000;
>>   	nominal_freq *= 1000;
>> -
>>   	WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
> 
> So cpudata->nominal_freq will be in KHz here.
> 
> 
>> -	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);
>>   
>> -	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
>> -	WRITE_ONCE(cpudata->max_freq, max_freq);
>> +	if (quirks && quirks->lowest_freq) {
>> +		min_freq = quirks->lowest_freq;
>> +	} else
>> +		min_freq = cppc_perf.lowest_freq;
>>
> 
> Since cppc_perf exposes the frequency values in MHz, min_freq is in MHz.
> 
>>   	/**
>>   	 * Below values need to be initialized correctly, otherwise driver will fail to load
>> @@ -937,12 +927,15 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>>   	 * 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);
>> +	if (nominal_freq <= 0) {
>> +		pr_err("nominal_freq(%d) value is incorrect\n",
>> +			nominal_freq);
>>   		return -EINVAL;
>>   	}
>>   
>> +	lowest_nonlinear_freq = perf_to_freq(cpudata, cpudata->lowest_nonlinear_perf);
> 
> Since lowest_nonlinear_freq will be computed using cpudata->nominal_freq, the former will be in KHz.
> 
>> +	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
>> +
>>   	if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq) {
>              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 
> And thus since lowest_nonlinear_freq is in KHz and min_freq is in MHz, this check will always be true.
> 
> Shouldn't the min_freq be multiplied by 1000 ?
>     

Yup, I think you're right.  Great catch!
I'll spin this for v3.

> 
>>   		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);
> 
> 

[PATCH v2 03/17] cpufreq/amd-pstate: Move perf values into a union

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

By storing perf values in a union all the writes and reads can
be done atomically, removing the need for some concurrency protections.

While making this change, also drop the cached frequency values,
using inline helpers to calculate them on demand from perf value.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * cache perf variable in unit tests
 * Drop unnecessary check from amd_pstate_update_min_max_limit()
 * Consistency with READ_ONCE()
 * Drop unneeded policy checks
 * add kdoc
---
 drivers/cpufreq/amd-pstate-ut.c |  18 +--
 drivers/cpufreq/amd-pstate.c    | 197 ++++++++++++++++++--------------
 drivers/cpufreq/amd-pstate.h    |  49 +++++---
 3 files changed, 152 insertions(+), 112 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index 445278cf40b61..ba3e06f349c6d 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -129,6 +129,7 @@ static void amd_pstate_ut_check_perf(u32 index)
 	struct cppc_perf_caps cppc_perf;
 	struct cpufreq_policy *policy = NULL;
 	struct amd_cpudata *cpudata = NULL;
+	union perf_cached cur_perf;
 
 	for_each_possible_cpu(cpu) {
 		policy = cpufreq_cpu_get(cpu);
@@ -162,19 +163,20 @@ static void amd_pstate_ut_check_perf(u32 index)
 			lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
 		}
 
-		if (highest_perf != READ_ONCE(cpudata->highest_perf) && !cpudata->hw_prefcore) {
+		cur_perf = READ_ONCE(cpudata->perf);
+		if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
 			pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
-				__func__, cpu, highest_perf, cpudata->highest_perf);
+				__func__, cpu, highest_perf, cpudata->perf.highest_perf);
 			goto skip_test;
 		}
-		if ((nominal_perf != READ_ONCE(cpudata->nominal_perf)) ||
-			(lowest_nonlinear_perf != READ_ONCE(cpudata->lowest_nonlinear_perf)) ||
-			(lowest_perf != READ_ONCE(cpudata->lowest_perf))) {
+		if (nominal_perf != cur_perf.nominal_perf ||
+		   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
+		   (lowest_perf != cur_perf.lowest_perf)) {
 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
-				__func__, cpu, nominal_perf, cpudata->nominal_perf,
-				lowest_nonlinear_perf, cpudata->lowest_nonlinear_perf,
-				lowest_perf, cpudata->lowest_perf);
+				__func__, cpu, nominal_perf, cpudata->perf.nominal_perf,
+				lowest_nonlinear_perf, cpudata->perf.lowest_nonlinear_perf,
+				lowest_perf, cpudata->perf.lowest_perf);
 			goto skip_test;
 		}
 
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index bcebdc4167fe0..8c3b54030ec56 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -142,18 +142,17 @@ static struct quirk_entry quirk_amd_7k62 = {
 	.lowest_freq = 550,
 };
 
-static inline u8 freq_to_perf(struct amd_cpudata *cpudata, unsigned int freq_val)
+static inline u8 freq_to_perf(union perf_cached perf, u32 nominal_freq, unsigned int freq_val)
 {
-	u8 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * cpudata->nominal_perf,
-					cpudata->nominal_freq);
+	u8 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * perf.nominal_perf, nominal_freq);
 
-	return clamp_t(u8, perf_val, cpudata->lowest_perf, cpudata->highest_perf);
+	return clamp_t(u8, perf_val, perf.lowest_perf, perf.highest_perf);
 }
 
-static inline u32 perf_to_freq(struct amd_cpudata *cpudata, u8 perf_val)
+static inline u32 perf_to_freq(union perf_cached perf, u32 nominal_freq, u8 perf_val)
 {
-	return DIV_ROUND_UP_ULL((u64)cpudata->nominal_freq * perf_val,
-				cpudata->nominal_perf);
+	return DIV_ROUND_UP_ULL((u64)nominal_freq * perf_val,
+				perf.nominal_perf);
 }
 
 static int __init dmi_matched_7k62_bios_bug(const struct dmi_system_id *dmi)
@@ -347,7 +346,9 @@ static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
 	}
 
 	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
+		union perf_cached perf = READ_ONCE(cpudata->perf);
+
+		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
 					  epp,
 					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
 					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
@@ -425,6 +426,7 @@ static inline int amd_pstate_cppc_enable(bool enable)
 
 static int msr_init_perf(struct amd_cpudata *cpudata)
 {
+	union perf_cached perf = READ_ONCE(cpudata->perf);
 	u64 cap1, numerator;
 
 	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
@@ -436,19 +438,21 @@ static int msr_init_perf(struct amd_cpudata *cpudata)
 	if (ret)
 		return ret;
 
-	WRITE_ONCE(cpudata->highest_perf, numerator);
-	WRITE_ONCE(cpudata->max_limit_perf, numerator);
-	WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
-	WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
-	WRITE_ONCE(cpudata->lowest_perf, AMD_CPPC_LOWEST_PERF(cap1));
+	perf.highest_perf = numerator;
+	perf.max_limit_perf = numerator;
+	perf.min_limit_perf = AMD_CPPC_LOWEST_PERF(cap1);
+	perf.nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
+	perf.lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
+	perf.lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
+	WRITE_ONCE(cpudata->perf, perf);
 	WRITE_ONCE(cpudata->prefcore_ranking, AMD_CPPC_HIGHEST_PERF(cap1));
-	WRITE_ONCE(cpudata->min_limit_perf, AMD_CPPC_LOWEST_PERF(cap1));
 	return 0;
 }
 
 static int shmem_init_perf(struct amd_cpudata *cpudata)
 {
 	struct cppc_perf_caps cppc_perf;
+	union perf_cached perf = READ_ONCE(cpudata->perf);
 	u64 numerator;
 
 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
@@ -459,14 +463,14 @@ static int shmem_init_perf(struct amd_cpudata *cpudata)
 	if (ret)
 		return ret;
 
-	WRITE_ONCE(cpudata->highest_perf, numerator);
-	WRITE_ONCE(cpudata->max_limit_perf, numerator);
-	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
-	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
-		   cppc_perf.lowest_nonlinear_perf);
-	WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf);
+	perf.highest_perf = numerator;
+	perf.max_limit_perf = numerator;
+	perf.min_limit_perf = cppc_perf.lowest_perf;
+	perf.nominal_perf = cppc_perf.nominal_perf;
+	perf.lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
+	perf.lowest_perf = cppc_perf.lowest_perf;
+	WRITE_ONCE(cpudata->perf, perf);
 	WRITE_ONCE(cpudata->prefcore_ranking, cppc_perf.highest_perf);
-	WRITE_ONCE(cpudata->min_limit_perf, cppc_perf.lowest_perf);
 
 	if (cppc_state == AMD_PSTATE_ACTIVE)
 		return 0;
@@ -549,14 +553,14 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
 			      u8 des_perf, u8 max_perf, bool fast_switch, int gov_flags)
 {
 	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpudata->cpu);
-	u8 nominal_perf = READ_ONCE(cpudata->nominal_perf);
+	union perf_cached perf = READ_ONCE(cpudata->perf);
 
 	if (!policy)
 		return;
 
 	des_perf = clamp_t(u8, des_perf, min_perf, max_perf);
 
-	policy->cur = perf_to_freq(cpudata, des_perf);
+	policy->cur = perf_to_freq(perf, cpudata->nominal_freq, des_perf);
 
 	if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) {
 		min_perf = des_perf;
@@ -565,7 +569,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
 
 	/* limit the max perf when core performance boost feature is disabled */
 	if (!cpudata->boost_supported)
-		max_perf = min_t(u8, nominal_perf, max_perf);
+		max_perf = min_t(u8, perf.nominal_perf, max_perf);
 
 	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
 		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
@@ -602,39 +606,41 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
 	return 0;
 }
 
-static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
+static void amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
 {
-	u8 max_limit_perf, min_limit_perf;
 	struct amd_cpudata *cpudata = policy->driver_data;
+	union perf_cached perf = READ_ONCE(cpudata->perf);
 
-	max_limit_perf = freq_to_perf(cpudata, policy->max);
-	min_limit_perf = freq_to_perf(cpudata, policy->min);
+	perf.max_limit_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->max);
+	perf.min_limit_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->min);
 
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
-		min_limit_perf = min(cpudata->nominal_perf, max_limit_perf);
+		perf.min_limit_perf = min(perf.nominal_perf, perf.max_limit_perf);
 
-	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
-	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
 	WRITE_ONCE(cpudata->max_limit_freq, policy->max);
 	WRITE_ONCE(cpudata->min_limit_freq, policy->min);
-
-	return 0;
+	WRITE_ONCE(cpudata->perf, perf);
 }
 
 static int amd_pstate_update_freq(struct cpufreq_policy *policy,
 				  unsigned int target_freq, bool fast_switch)
 {
 	struct cpufreq_freqs freqs;
-	struct amd_cpudata *cpudata = policy->driver_data;
+	struct amd_cpudata *cpudata;
+	union perf_cached perf;
 	u8 des_perf;
 
+	cpudata = policy->driver_data;
+
 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
 		amd_pstate_update_min_max_limit(policy);
 
+	perf = READ_ONCE(cpudata->perf);
+
 	freqs.old = policy->cur;
 	freqs.new = target_freq;
 
-	des_perf = freq_to_perf(cpudata, target_freq);
+	des_perf = freq_to_perf(perf, cpudata->nominal_freq, target_freq);
 
 	WARN_ON(fast_switch && !policy->fast_switch_enabled);
 	/*
@@ -645,8 +651,8 @@ static int amd_pstate_update_freq(struct cpufreq_policy *policy,
 	if (!fast_switch)
 		cpufreq_freq_transition_begin(policy, &freqs);
 
-	amd_pstate_update(cpudata, cpudata->min_limit_perf, des_perf,
-			  cpudata->max_limit_perf, fast_switch,
+	amd_pstate_update(cpudata, perf.min_limit_perf, des_perf,
+			  perf.max_limit_perf, fast_switch,
 			  policy->governor->flags);
 
 	if (!fast_switch)
@@ -675,9 +681,10 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 				   unsigned long target_perf,
 				   unsigned long capacity)
 {
-	u8 max_perf, min_perf, des_perf, cap_perf, min_limit_perf;
+	u8 max_perf, min_perf, des_perf, cap_perf;
 	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
 	struct amd_cpudata *cpudata;
+	union perf_cached perf;
 
 	if (!policy)
 		return;
@@ -687,8 +694,8 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 	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);
-	min_limit_perf = READ_ONCE(cpudata->min_limit_perf);
+	perf = READ_ONCE(cpudata->perf);
+	cap_perf = perf.highest_perf;
 
 	des_perf = cap_perf;
 	if (target_perf < capacity)
@@ -699,10 +706,10 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 	else
 		min_perf = cap_perf;
 
-	if (min_perf < min_limit_perf)
-		min_perf = min_limit_perf;
+	if (min_perf < perf.min_limit_perf)
+		min_perf = perf.min_limit_perf;
 
-	max_perf = cpudata->max_limit_perf;
+	max_perf = perf.max_limit_perf;
 	if (max_perf < min_perf)
 		max_perf = min_perf;
 
@@ -713,11 +720,12 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
+	union perf_cached perf = READ_ONCE(cpudata->perf);
 	u32 nominal_freq, max_freq;
 	int ret = 0;
 
 	nominal_freq = READ_ONCE(cpudata->nominal_freq);
-	max_freq = perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf));
+	max_freq = perf_to_freq(perf, cpudata->nominal_freq, perf.highest_perf);
 
 	if (on)
 		policy->cpuinfo.max_freq = max_freq;
@@ -888,25 +896,24 @@ static u32 amd_pstate_get_transition_latency(unsigned int cpu)
 }
 
 /*
- * amd_pstate_init_freq: Initialize the max_freq, min_freq,
- *                       nominal_freq and lowest_nonlinear_freq for
- *                       the @cpudata object.
+ * amd_pstate_init_freq: Initialize the 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.
+ * Requires: all perf members of @cpudata to be initialized.
  *
- *  Returns 0 on success, non-zero value on failure.
+ * Returns 0 on success, non-zero value on failure.
  */
 static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 {
-	int ret;
 	u32 min_freq, nominal_freq, lowest_nonlinear_freq;
 	struct cppc_perf_caps cppc_perf;
+	union perf_cached perf;
+	int ret;
 
 	ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
 	if (ret)
 		return ret;
+	perf = READ_ONCE(cpudata->perf);
 
 	if (quirks && quirks->nominal_freq)
 		nominal_freq = quirks->nominal_freq;
@@ -918,6 +925,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 
 	if (quirks && quirks->lowest_freq) {
 		min_freq = quirks->lowest_freq;
+		perf.lowest_perf = freq_to_perf(perf, nominal_freq, min_freq);
 	} else
 		min_freq = cppc_perf.lowest_freq;
 
@@ -933,7 +941,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 		return -EINVAL;
 	}
 
-	lowest_nonlinear_freq = perf_to_freq(cpudata, cpudata->lowest_nonlinear_perf);
+	lowest_nonlinear_freq = perf_to_freq(perf, nominal_freq, perf.lowest_nonlinear_perf);
 	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
 
 	if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq) {
@@ -948,6 +956,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata;
+	union perf_cached perf;
 	struct device *dev;
 	int ret;
 
@@ -983,8 +992,14 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu);
 	policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu);
 
-	policy->cpuinfo.min_freq = policy->min = perf_to_freq(cpudata, cpudata->lowest_perf);
-	policy->cpuinfo.max_freq = policy->max = perf_to_freq(cpudata, cpudata->highest_perf);
+	perf = READ_ONCE(cpudata->perf);
+
+	policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
+							      cpudata->nominal_freq,
+							      perf.lowest_perf);
+	policy->cpuinfo.max_freq = policy->max = perf_to_freq(perf,
+							      cpudata->nominal_freq,
+							      perf.highest_perf);
 
 	policy->boost_enabled = READ_ONCE(cpudata->boost_supported);
 
@@ -1065,23 +1080,27 @@ static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
 static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy,
 					char *buf)
 {
-	struct amd_cpudata *cpudata = policy->driver_data;
+	struct amd_cpudata *cpudata;
+	union perf_cached perf;
 
+	cpudata = policy->driver_data;
+	perf = READ_ONCE(cpudata->perf);
 
-	return sysfs_emit(buf, "%u\n", perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf)));
+	return sysfs_emit(buf, "%u\n",
+			  perf_to_freq(perf, cpudata->nominal_freq, perf.max_limit_perf));
 }
 
 static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy,
 						     char *buf)
 {
-	int freq;
-	struct amd_cpudata *cpudata = policy->driver_data;
+	struct amd_cpudata *cpudata;
+	union perf_cached perf;
 
-	freq = READ_ONCE(cpudata->lowest_nonlinear_freq);
-	if (freq < 0)
-		return freq;
+	cpudata = policy->driver_data;
+	perf = READ_ONCE(cpudata->perf);
 
-	return sysfs_emit(buf, "%u\n", freq);
+	return sysfs_emit(buf, "%u\n",
+			  perf_to_freq(perf, cpudata->nominal_freq, perf.lowest_nonlinear_perf));
 }
 
 /*
@@ -1091,12 +1110,11 @@ static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *poli
 static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy,
 					    char *buf)
 {
-	u8 perf;
-	struct amd_cpudata *cpudata = policy->driver_data;
+	struct amd_cpudata *cpudata;
 
-	perf = READ_ONCE(cpudata->highest_perf);
+	cpudata = policy->driver_data;
 
-	return sysfs_emit(buf, "%u\n", perf);
+	return sysfs_emit(buf, "%u\n", cpudata->perf.highest_perf);
 }
 
 static ssize_t show_amd_pstate_prefcore_ranking(struct cpufreq_policy *policy,
@@ -1427,6 +1445,7 @@ static bool amd_pstate_acpi_pm_profile_undefined(void)
 static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata;
+	union perf_cached perf;
 	struct device *dev;
 	u64 value;
 	int ret;
@@ -1460,8 +1479,15 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
-	policy->cpuinfo.min_freq = policy->min = perf_to_freq(cpudata, cpudata->lowest_perf);
-	policy->cpuinfo.max_freq = policy->max = perf_to_freq(cpudata, cpudata->highest_perf);
+	perf = READ_ONCE(cpudata->perf);
+
+	policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
+							      cpudata->nominal_freq,
+							      perf.lowest_perf);
+	policy->cpuinfo.max_freq = policy->max = perf_to_freq(perf,
+							      cpudata->nominal_freq,
+							      perf.highest_perf);
+
 	/* It will be updated by governor */
 	policy->cur = policy->cpuinfo.min_freq;
 
@@ -1522,6 +1548,7 @@ static void amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
 static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
+	union perf_cached perf;
 	u8 epp;
 
 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
@@ -1532,15 +1559,16 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	else
 		epp = READ_ONCE(cpudata->epp_cached);
 
+	perf = READ_ONCE(cpudata->perf);
 	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf, epp,
-					  cpudata->min_limit_perf,
-					  cpudata->max_limit_perf,
+		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf, epp,
+					  perf.min_limit_perf,
+					  perf.max_limit_perf,
 					  policy->boost_enabled);
 	}
 
-	return amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
-				      cpudata->max_limit_perf, epp, false);
+	return amd_pstate_update_perf(cpudata, perf.min_limit_perf, 0U,
+				      perf.max_limit_perf, epp, false);
 }
 
 static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
@@ -1572,23 +1600,21 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
 static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
-	u8 max_perf;
+	union perf_cached perf = READ_ONCE(cpudata->perf);
 	int ret;
 
 	ret = amd_pstate_cppc_enable(true);
 	if (ret)
 		pr_err("failed to enable amd pstate during resume, return %d\n", ret);
 
-	max_perf = READ_ONCE(cpudata->highest_perf);
-
 	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
+		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
 					  cpudata->epp_cached,
 					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
-					  max_perf, policy->boost_enabled);
+					  perf.highest_perf, policy->boost_enabled);
 	}
 
-	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
+	return amd_pstate_update_perf(cpudata, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
 }
 
 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
@@ -1609,22 +1635,21 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
 static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
-	u8 min_perf;
+	union perf_cached perf = READ_ONCE(cpudata->perf);
 
 	if (cpudata->suspended)
 		return 0;
 
-	min_perf = READ_ONCE(cpudata->lowest_perf);
-
 	guard(mutex)(&amd_pstate_limits_lock);
 
 	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
+		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
 					  AMD_CPPC_EPP_BALANCE_POWERSAVE,
-					  min_perf, min_perf, policy->boost_enabled);
+					  perf.lowest_perf, perf.lowest_perf,
+					  policy->boost_enabled);
 	}
 
-	return amd_pstate_update_perf(cpudata, min_perf, 0, min_perf,
+	return amd_pstate_update_perf(cpudata, perf.lowest_perf, 0, perf.lowest_perf,
 				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
 }
 
diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
index 0149933692458..8421c83c07919 100644
--- a/drivers/cpufreq/amd-pstate.h
+++ b/drivers/cpufreq/amd-pstate.h
@@ -13,6 +13,34 @@
 /*********************************************************************
  *                        AMD P-state INTERFACE                       *
  *********************************************************************/
+
+/**
+ * union perf_cached - A union to cache performance-related data.
+ * @highest_perf: the maximum performance an individual processor may reach,
+ *		  assuming ideal conditions
+ *		  For platforms that do not support the preferred core feature, the
+ *		  highest_pef may be configured with 166 or 255, to avoid max frequency
+ *		  calculated wrongly. we take the fixed value as the highest_perf.
+ * @nominal_perf: the maximum sustained performance level of the processor,
+ *		  assuming ideal operating conditions
+ * @lowest_nonlinear_perf: the lowest performance level at which nonlinear power
+ *			   savings are achieved
+ * @lowest_perf: the absolute lowest performance level of the processor
+ * @min_limit_perf: Cached value of the performance corresponding to policy->min
+ * @max_limit_perf: Cached value of the performance corresponding to policy->max
+ */
+union perf_cached {
+	struct {
+		u8	highest_perf;
+		u8	nominal_perf;
+		u8	lowest_nonlinear_perf;
+		u8	lowest_perf;
+		u8	min_limit_perf;
+		u8	max_limit_perf;
+	};
+	u64	val;
+};
+
 /**
  * struct  amd_aperf_mperf
  * @aperf: actual performance frequency clock count
@@ -30,20 +58,9 @@ struct amd_aperf_mperf {
  * @cpu: CPU number
  * @req: constraint request to apply
  * @cppc_req_cached: cached performance request hints
- * @highest_perf: the maximum performance an individual processor may reach,
- *		  assuming ideal conditions
- *		  For platforms that do not support the preferred core feature, the
- *		  highest_pef may be configured with 166 or 255, to avoid max frequency
- *		  calculated wrongly. we take the fixed value as the highest_perf.
- * @nominal_perf: the maximum sustained performance level of the processor,
- *		  assuming ideal operating conditions
- * @lowest_nonlinear_perf: the lowest performance level at which nonlinear power
- *			   savings are achieved
- * @lowest_perf: the absolute lowest performance level of the processor
+ * @perf: cached performance-related data
  * @prefcore_ranking: the preferred core ranking, the higher value indicates a higher
  * 		  priority.
- * @min_limit_perf: Cached value of the performance corresponding to policy->min
- * @max_limit_perf: Cached value of the performance corresponding to policy->max
  * @min_limit_freq: Cached value of policy->min (in khz)
  * @max_limit_freq: Cached value of policy->max (in khz)
  * @nominal_freq: the frequency (in khz) that mapped to nominal_perf
@@ -68,13 +85,9 @@ struct amd_cpudata {
 	struct	freq_qos_request req[2];
 	u64	cppc_req_cached;
 
-	u8	highest_perf;
-	u8	nominal_perf;
-	u8	lowest_nonlinear_perf;
-	u8	lowest_perf;
+	union perf_cached perf;
+
 	u8	prefcore_ranking;
-	u8	min_limit_perf;
-	u8	max_limit_perf;
 	u32	min_limit_freq;
 	u32	max_limit_freq;
 	u32	nominal_freq;
-- 
2.43.0

Re: [PATCH v2 03/17] cpufreq/amd-pstate: Move perf values into a union

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:30PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> By storing perf values in a union all the writes and reads can
> be done atomically, removing the need for some concurrency protections.
> 
> While making this change, also drop the cached frequency values,
> using inline helpers to calculate them on demand from perf value.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Looks good to me.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.



> ---
> v2:
>  * cache perf variable in unit tests
>  * Drop unnecessary check from amd_pstate_update_min_max_limit()
>  * Consistency with READ_ONCE()
>  * Drop unneeded policy checks
>  * add kdoc
> ---
>  drivers/cpufreq/amd-pstate-ut.c |  18 +--
>  drivers/cpufreq/amd-pstate.c    | 197 ++++++++++++++++++--------------
>  drivers/cpufreq/amd-pstate.h    |  49 +++++---
>  3 files changed, 152 insertions(+), 112 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index 445278cf40b61..ba3e06f349c6d 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -129,6 +129,7 @@ static void amd_pstate_ut_check_perf(u32 index)
>  	struct cppc_perf_caps cppc_perf;
>  	struct cpufreq_policy *policy = NULL;
>  	struct amd_cpudata *cpudata = NULL;
> +	union perf_cached cur_perf;
>  
>  	for_each_possible_cpu(cpu) {
>  		policy = cpufreq_cpu_get(cpu);
> @@ -162,19 +163,20 @@ static void amd_pstate_ut_check_perf(u32 index)
>  			lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
>  		}
>  
> -		if (highest_perf != READ_ONCE(cpudata->highest_perf) && !cpudata->hw_prefcore) {
> +		cur_perf = READ_ONCE(cpudata->perf);
> +		if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
>  			pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
> -				__func__, cpu, highest_perf, cpudata->highest_perf);
> +				__func__, cpu, highest_perf, cpudata->perf.highest_perf);
>  			goto skip_test;
>  		}
> -		if ((nominal_perf != READ_ONCE(cpudata->nominal_perf)) ||
> -			(lowest_nonlinear_perf != READ_ONCE(cpudata->lowest_nonlinear_perf)) ||
> -			(lowest_perf != READ_ONCE(cpudata->lowest_perf))) {
> +		if (nominal_perf != cur_perf.nominal_perf ||
> +		   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
> +		   (lowest_perf != cur_perf.lowest_perf)) {
>  			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
> -				__func__, cpu, nominal_perf, cpudata->nominal_perf,
> -				lowest_nonlinear_perf, cpudata->lowest_nonlinear_perf,
> -				lowest_perf, cpudata->lowest_perf);
> +				__func__, cpu, nominal_perf, cpudata->perf.nominal_perf,
> +				lowest_nonlinear_perf, cpudata->perf.lowest_nonlinear_perf,
> +				lowest_perf, cpudata->perf.lowest_perf);
>  			goto skip_test;
>  		}
>  
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index bcebdc4167fe0..8c3b54030ec56 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -142,18 +142,17 @@ static struct quirk_entry quirk_amd_7k62 = {
>  	.lowest_freq = 550,
>  };
>  
> -static inline u8 freq_to_perf(struct amd_cpudata *cpudata, unsigned int freq_val)
> +static inline u8 freq_to_perf(union perf_cached perf, u32 nominal_freq, unsigned int freq_val)
>  {
> -	u8 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * cpudata->nominal_perf,
> -					cpudata->nominal_freq);
> +	u8 perf_val = DIV_ROUND_UP_ULL((u64)freq_val * perf.nominal_perf, nominal_freq);
>  
> -	return clamp_t(u8, perf_val, cpudata->lowest_perf, cpudata->highest_perf);
> +	return clamp_t(u8, perf_val, perf.lowest_perf, perf.highest_perf);
>  }
>  
> -static inline u32 perf_to_freq(struct amd_cpudata *cpudata, u8 perf_val)
> +static inline u32 perf_to_freq(union perf_cached perf, u32 nominal_freq, u8 perf_val)
>  {
> -	return DIV_ROUND_UP_ULL((u64)cpudata->nominal_freq * perf_val,
> -				cpudata->nominal_perf);
> +	return DIV_ROUND_UP_ULL((u64)nominal_freq * perf_val,
> +				perf.nominal_perf);
>  }
>  
>  static int __init dmi_matched_7k62_bios_bug(const struct dmi_system_id *dmi)
> @@ -347,7 +346,9 @@ static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
>  	}
>  
>  	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
> +		union perf_cached perf = READ_ONCE(cpudata->perf);
> +
> +		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
>  					  epp,
>  					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
>  					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
> @@ -425,6 +426,7 @@ static inline int amd_pstate_cppc_enable(bool enable)
>  
>  static int msr_init_perf(struct amd_cpudata *cpudata)
>  {
> +	union perf_cached perf = READ_ONCE(cpudata->perf);
>  	u64 cap1, numerator;
>  
>  	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
> @@ -436,19 +438,21 @@ static int msr_init_perf(struct amd_cpudata *cpudata)
>  	if (ret)
>  		return ret;
>  
> -	WRITE_ONCE(cpudata->highest_perf, numerator);
> -	WRITE_ONCE(cpudata->max_limit_perf, numerator);
> -	WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
> -	WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
> -	WRITE_ONCE(cpudata->lowest_perf, AMD_CPPC_LOWEST_PERF(cap1));
> +	perf.highest_perf = numerator;
> +	perf.max_limit_perf = numerator;
> +	perf.min_limit_perf = AMD_CPPC_LOWEST_PERF(cap1);
> +	perf.nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
> +	perf.lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
> +	perf.lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
> +	WRITE_ONCE(cpudata->perf, perf);
>  	WRITE_ONCE(cpudata->prefcore_ranking, AMD_CPPC_HIGHEST_PERF(cap1));
> -	WRITE_ONCE(cpudata->min_limit_perf, AMD_CPPC_LOWEST_PERF(cap1));
>  	return 0;
>  }
>  
>  static int shmem_init_perf(struct amd_cpudata *cpudata)
>  {
>  	struct cppc_perf_caps cppc_perf;
> +	union perf_cached perf = READ_ONCE(cpudata->perf);
>  	u64 numerator;
>  
>  	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
> @@ -459,14 +463,14 @@ static int shmem_init_perf(struct amd_cpudata *cpudata)
>  	if (ret)
>  		return ret;
>  
> -	WRITE_ONCE(cpudata->highest_perf, numerator);
> -	WRITE_ONCE(cpudata->max_limit_perf, numerator);
> -	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
> -	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
> -		   cppc_perf.lowest_nonlinear_perf);
> -	WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf);
> +	perf.highest_perf = numerator;
> +	perf.max_limit_perf = numerator;
> +	perf.min_limit_perf = cppc_perf.lowest_perf;
> +	perf.nominal_perf = cppc_perf.nominal_perf;
> +	perf.lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
> +	perf.lowest_perf = cppc_perf.lowest_perf;
> +	WRITE_ONCE(cpudata->perf, perf);
>  	WRITE_ONCE(cpudata->prefcore_ranking, cppc_perf.highest_perf);
> -	WRITE_ONCE(cpudata->min_limit_perf, cppc_perf.lowest_perf);
>  
>  	if (cppc_state == AMD_PSTATE_ACTIVE)
>  		return 0;
> @@ -549,14 +553,14 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
>  			      u8 des_perf, u8 max_perf, bool fast_switch, int gov_flags)
>  {
>  	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpudata->cpu);
> -	u8 nominal_perf = READ_ONCE(cpudata->nominal_perf);
> +	union perf_cached perf = READ_ONCE(cpudata->perf);
>  
>  	if (!policy)
>  		return;
>  
>  	des_perf = clamp_t(u8, des_perf, min_perf, max_perf);
>  
> -	policy->cur = perf_to_freq(cpudata, des_perf);
> +	policy->cur = perf_to_freq(perf, cpudata->nominal_freq, des_perf);
>  
>  	if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) {
>  		min_perf = des_perf;
> @@ -565,7 +569,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
>  
>  	/* limit the max perf when core performance boost feature is disabled */
>  	if (!cpudata->boost_supported)
> -		max_perf = min_t(u8, nominal_perf, max_perf);
> +		max_perf = min_t(u8, perf.nominal_perf, max_perf);
>  
>  	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
>  		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
> @@ -602,39 +606,41 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
>  	return 0;
>  }
>  
> -static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
> +static void amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
>  {
> -	u8 max_limit_perf, min_limit_perf;
>  	struct amd_cpudata *cpudata = policy->driver_data;
> +	union perf_cached perf = READ_ONCE(cpudata->perf);
>  
> -	max_limit_perf = freq_to_perf(cpudata, policy->max);
> -	min_limit_perf = freq_to_perf(cpudata, policy->min);
> +	perf.max_limit_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->max);
> +	perf.min_limit_perf = freq_to_perf(perf, cpudata->nominal_freq, policy->min);
>  
>  	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
> -		min_limit_perf = min(cpudata->nominal_perf, max_limit_perf);
> +		perf.min_limit_perf = min(perf.nominal_perf, perf.max_limit_perf);
>  
> -	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
> -	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
>  	WRITE_ONCE(cpudata->max_limit_freq, policy->max);
>  	WRITE_ONCE(cpudata->min_limit_freq, policy->min);
> -
> -	return 0;
> +	WRITE_ONCE(cpudata->perf, perf);
>  }
>  
>  static int amd_pstate_update_freq(struct cpufreq_policy *policy,
>  				  unsigned int target_freq, bool fast_switch)
>  {
>  	struct cpufreq_freqs freqs;
> -	struct amd_cpudata *cpudata = policy->driver_data;
> +	struct amd_cpudata *cpudata;
> +	union perf_cached perf;
>  	u8 des_perf;
>  
> +	cpudata = policy->driver_data;
> +
>  	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
>  		amd_pstate_update_min_max_limit(policy);
>  
> +	perf = READ_ONCE(cpudata->perf);
> +
>  	freqs.old = policy->cur;
>  	freqs.new = target_freq;
>  
> -	des_perf = freq_to_perf(cpudata, target_freq);
> +	des_perf = freq_to_perf(perf, cpudata->nominal_freq, target_freq);
>  
>  	WARN_ON(fast_switch && !policy->fast_switch_enabled);
>  	/*
> @@ -645,8 +651,8 @@ static int amd_pstate_update_freq(struct cpufreq_policy *policy,
>  	if (!fast_switch)
>  		cpufreq_freq_transition_begin(policy, &freqs);
>  
> -	amd_pstate_update(cpudata, cpudata->min_limit_perf, des_perf,
> -			  cpudata->max_limit_perf, fast_switch,
> +	amd_pstate_update(cpudata, perf.min_limit_perf, des_perf,
> +			  perf.max_limit_perf, fast_switch,
>  			  policy->governor->flags);
>  
>  	if (!fast_switch)
> @@ -675,9 +681,10 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
>  				   unsigned long target_perf,
>  				   unsigned long capacity)
>  {
> -	u8 max_perf, min_perf, des_perf, cap_perf, min_limit_perf;
> +	u8 max_perf, min_perf, des_perf, cap_perf;
>  	struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
>  	struct amd_cpudata *cpudata;
> +	union perf_cached perf;
>  
>  	if (!policy)
>  		return;
> @@ -687,8 +694,8 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
>  	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);
> -	min_limit_perf = READ_ONCE(cpudata->min_limit_perf);
> +	perf = READ_ONCE(cpudata->perf);
> +	cap_perf = perf.highest_perf;
>  
>  	des_perf = cap_perf;
>  	if (target_perf < capacity)
> @@ -699,10 +706,10 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
>  	else
>  		min_perf = cap_perf;
>  
> -	if (min_perf < min_limit_perf)
> -		min_perf = min_limit_perf;
> +	if (min_perf < perf.min_limit_perf)
> +		min_perf = perf.min_limit_perf;
>  
> -	max_perf = cpudata->max_limit_perf;
> +	max_perf = perf.max_limit_perf;
>  	if (max_perf < min_perf)
>  		max_perf = min_perf;
>  
> @@ -713,11 +720,12 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
>  static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
>  {
>  	struct amd_cpudata *cpudata = policy->driver_data;
> +	union perf_cached perf = READ_ONCE(cpudata->perf);
>  	u32 nominal_freq, max_freq;
>  	int ret = 0;
>  
>  	nominal_freq = READ_ONCE(cpudata->nominal_freq);
> -	max_freq = perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf));
> +	max_freq = perf_to_freq(perf, cpudata->nominal_freq, perf.highest_perf);
>  
>  	if (on)
>  		policy->cpuinfo.max_freq = max_freq;
> @@ -888,25 +896,24 @@ static u32 amd_pstate_get_transition_latency(unsigned int cpu)
>  }
>  
>  /*
> - * amd_pstate_init_freq: Initialize the max_freq, min_freq,
> - *                       nominal_freq and lowest_nonlinear_freq for
> - *                       the @cpudata object.
> + * amd_pstate_init_freq: Initialize the 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.
> + * Requires: all perf members of @cpudata to be initialized.
>   *
> - *  Returns 0 on success, non-zero value on failure.
> + * Returns 0 on success, non-zero value on failure.
>   */
>  static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>  {
> -	int ret;
>  	u32 min_freq, nominal_freq, lowest_nonlinear_freq;
>  	struct cppc_perf_caps cppc_perf;
> +	union perf_cached perf;
> +	int ret;
>  
>  	ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
>  	if (ret)
>  		return ret;
> +	perf = READ_ONCE(cpudata->perf);
>  
>  	if (quirks && quirks->nominal_freq)
>  		nominal_freq = quirks->nominal_freq;
> @@ -918,6 +925,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>  
>  	if (quirks && quirks->lowest_freq) {
>  		min_freq = quirks->lowest_freq;
> +		perf.lowest_perf = freq_to_perf(perf, nominal_freq, min_freq);
>  	} else
>  		min_freq = cppc_perf.lowest_freq;
>  
> @@ -933,7 +941,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>  		return -EINVAL;
>  	}
>  
> -	lowest_nonlinear_freq = perf_to_freq(cpudata, cpudata->lowest_nonlinear_perf);
> +	lowest_nonlinear_freq = perf_to_freq(perf, nominal_freq, perf.lowest_nonlinear_perf);
>  	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
>  
>  	if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq) {
> @@ -948,6 +956,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
>  static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
>  {
>  	struct amd_cpudata *cpudata;
> +	union perf_cached perf;
>  	struct device *dev;
>  	int ret;
>  
> @@ -983,8 +992,14 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
>  	policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu);
>  	policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu);
>  
> -	policy->cpuinfo.min_freq = policy->min = perf_to_freq(cpudata, cpudata->lowest_perf);
> -	policy->cpuinfo.max_freq = policy->max = perf_to_freq(cpudata, cpudata->highest_perf);
> +	perf = READ_ONCE(cpudata->perf);
> +
> +	policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
> +							      cpudata->nominal_freq,
> +							      perf.lowest_perf);
> +	policy->cpuinfo.max_freq = policy->max = perf_to_freq(perf,
> +							      cpudata->nominal_freq,
> +							      perf.highest_perf);
>  
>  	policy->boost_enabled = READ_ONCE(cpudata->boost_supported);
>  
> @@ -1065,23 +1080,27 @@ static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
>  static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy,
>  					char *buf)
>  {
> -	struct amd_cpudata *cpudata = policy->driver_data;
> +	struct amd_cpudata *cpudata;
> +	union perf_cached perf;
>  
> +	cpudata = policy->driver_data;
> +	perf = READ_ONCE(cpudata->perf);
>  
> -	return sysfs_emit(buf, "%u\n", perf_to_freq(cpudata, READ_ONCE(cpudata->highest_perf)));
> +	return sysfs_emit(buf, "%u\n",
> +			  perf_to_freq(perf, cpudata->nominal_freq, perf.max_limit_perf));
>  }
>  
>  static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy,
>  						     char *buf)
>  {
> -	int freq;
> -	struct amd_cpudata *cpudata = policy->driver_data;
> +	struct amd_cpudata *cpudata;
> +	union perf_cached perf;
>  
> -	freq = READ_ONCE(cpudata->lowest_nonlinear_freq);
> -	if (freq < 0)
> -		return freq;
> +	cpudata = policy->driver_data;
> +	perf = READ_ONCE(cpudata->perf);
>  
> -	return sysfs_emit(buf, "%u\n", freq);
> +	return sysfs_emit(buf, "%u\n",
> +			  perf_to_freq(perf, cpudata->nominal_freq, perf.lowest_nonlinear_perf));
>  }
>  
>  /*
> @@ -1091,12 +1110,11 @@ static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *poli
>  static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy,
>  					    char *buf)
>  {
> -	u8 perf;
> -	struct amd_cpudata *cpudata = policy->driver_data;
> +	struct amd_cpudata *cpudata;
>  
> -	perf = READ_ONCE(cpudata->highest_perf);
> +	cpudata = policy->driver_data;
>  
> -	return sysfs_emit(buf, "%u\n", perf);
> +	return sysfs_emit(buf, "%u\n", cpudata->perf.highest_perf);
>  }
>  
>  static ssize_t show_amd_pstate_prefcore_ranking(struct cpufreq_policy *policy,
> @@ -1427,6 +1445,7 @@ static bool amd_pstate_acpi_pm_profile_undefined(void)
>  static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  {
>  	struct amd_cpudata *cpudata;
> +	union perf_cached perf;
>  	struct device *dev;
>  	u64 value;
>  	int ret;
> @@ -1460,8 +1479,15 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  	if (ret)
>  		goto free_cpudata1;
>  
> -	policy->cpuinfo.min_freq = policy->min = perf_to_freq(cpudata, cpudata->lowest_perf);
> -	policy->cpuinfo.max_freq = policy->max = perf_to_freq(cpudata, cpudata->highest_perf);
> +	perf = READ_ONCE(cpudata->perf);
> +
> +	policy->cpuinfo.min_freq = policy->min = perf_to_freq(perf,
> +							      cpudata->nominal_freq,
> +							      perf.lowest_perf);
> +	policy->cpuinfo.max_freq = policy->max = perf_to_freq(perf,
> +							      cpudata->nominal_freq,
> +							      perf.highest_perf);
> +
>  	/* It will be updated by governor */
>  	policy->cur = policy->cpuinfo.min_freq;
>  
> @@ -1522,6 +1548,7 @@ static void amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
>  static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>  {
>  	struct amd_cpudata *cpudata = policy->driver_data;
> +	union perf_cached perf;
>  	u8 epp;
>  
>  	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
> @@ -1532,15 +1559,16 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>  	else
>  		epp = READ_ONCE(cpudata->epp_cached);
>  
> +	perf = READ_ONCE(cpudata->perf);
>  	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf, epp,
> -					  cpudata->min_limit_perf,
> -					  cpudata->max_limit_perf,
> +		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf, epp,
> +					  perf.min_limit_perf,
> +					  perf.max_limit_perf,
>  					  policy->boost_enabled);
>  	}
>  
> -	return amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
> -				      cpudata->max_limit_perf, epp, false);
> +	return amd_pstate_update_perf(cpudata, perf.min_limit_perf, 0U,
> +				      perf.max_limit_perf, epp, false);
>  }
>  
>  static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
> @@ -1572,23 +1600,21 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>  static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
>  {
>  	struct amd_cpudata *cpudata = policy->driver_data;
> -	u8 max_perf;
> +	union perf_cached perf = READ_ONCE(cpudata->perf);
>  	int ret;
>  
>  	ret = amd_pstate_cppc_enable(true);
>  	if (ret)
>  		pr_err("failed to enable amd pstate during resume, return %d\n", ret);
>  
> -	max_perf = READ_ONCE(cpudata->highest_perf);
> -
>  	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
> +		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
>  					  cpudata->epp_cached,
>  					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> -					  max_perf, policy->boost_enabled);
> +					  perf.highest_perf, policy->boost_enabled);
>  	}
>  
> -	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
> +	return amd_pstate_update_perf(cpudata, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
>  }
>  
>  static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
> @@ -1609,22 +1635,21 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
>  static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
>  {
>  	struct amd_cpudata *cpudata = policy->driver_data;
> -	u8 min_perf;
> +	union perf_cached perf = READ_ONCE(cpudata->perf);
>  
>  	if (cpudata->suspended)
>  		return 0;
>  
> -	min_perf = READ_ONCE(cpudata->lowest_perf);
> -
>  	guard(mutex)(&amd_pstate_limits_lock);
>  
>  	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
> +		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
>  					  AMD_CPPC_EPP_BALANCE_POWERSAVE,
> -					  min_perf, min_perf, policy->boost_enabled);
> +					  perf.lowest_perf, perf.lowest_perf,
> +					  policy->boost_enabled);
>  	}
>  
> -	return amd_pstate_update_perf(cpudata, min_perf, 0, min_perf,
> +	return amd_pstate_update_perf(cpudata, perf.lowest_perf, 0, perf.lowest_perf,
>  				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
>  }
>  
> diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
> index 0149933692458..8421c83c07919 100644
> --- a/drivers/cpufreq/amd-pstate.h
> +++ b/drivers/cpufreq/amd-pstate.h
> @@ -13,6 +13,34 @@
>  /*********************************************************************
>   *                        AMD P-state INTERFACE                       *
>   *********************************************************************/
> +
> +/**
> + * union perf_cached - A union to cache performance-related data.
> + * @highest_perf: the maximum performance an individual processor may reach,
> + *		  assuming ideal conditions
> + *		  For platforms that do not support the preferred core feature, the
> + *		  highest_pef may be configured with 166 or 255, to avoid max frequency
> + *		  calculated wrongly. we take the fixed value as the highest_perf.
> + * @nominal_perf: the maximum sustained performance level of the processor,
> + *		  assuming ideal operating conditions
> + * @lowest_nonlinear_perf: the lowest performance level at which nonlinear power
> + *			   savings are achieved
> + * @lowest_perf: the absolute lowest performance level of the processor
> + * @min_limit_perf: Cached value of the performance corresponding to policy->min
> + * @max_limit_perf: Cached value of the performance corresponding to policy->max
> + */
> +union perf_cached {
> +	struct {
> +		u8	highest_perf;
> +		u8	nominal_perf;
> +		u8	lowest_nonlinear_perf;
> +		u8	lowest_perf;
> +		u8	min_limit_perf;
> +		u8	max_limit_perf;
> +	};
> +	u64	val;
> +};
> +
>  /**
>   * struct  amd_aperf_mperf
>   * @aperf: actual performance frequency clock count
> @@ -30,20 +58,9 @@ struct amd_aperf_mperf {
>   * @cpu: CPU number
>   * @req: constraint request to apply
>   * @cppc_req_cached: cached performance request hints
> - * @highest_perf: the maximum performance an individual processor may reach,
> - *		  assuming ideal conditions
> - *		  For platforms that do not support the preferred core feature, the
> - *		  highest_pef may be configured with 166 or 255, to avoid max frequency
> - *		  calculated wrongly. we take the fixed value as the highest_perf.
> - * @nominal_perf: the maximum sustained performance level of the processor,
> - *		  assuming ideal operating conditions
> - * @lowest_nonlinear_perf: the lowest performance level at which nonlinear power
> - *			   savings are achieved
> - * @lowest_perf: the absolute lowest performance level of the processor
> + * @perf: cached performance-related data
>   * @prefcore_ranking: the preferred core ranking, the higher value indicates a higher
>   * 		  priority.
> - * @min_limit_perf: Cached value of the performance corresponding to policy->min
> - * @max_limit_perf: Cached value of the performance corresponding to policy->max
>   * @min_limit_freq: Cached value of policy->min (in khz)
>   * @max_limit_freq: Cached value of policy->max (in khz)
>   * @nominal_freq: the frequency (in khz) that mapped to nominal_perf
> @@ -68,13 +85,9 @@ struct amd_cpudata {
>  	struct	freq_qos_request req[2];
>  	u64	cppc_req_cached;
>  
> -	u8	highest_perf;
> -	u8	nominal_perf;
> -	u8	lowest_nonlinear_perf;
> -	u8	lowest_perf;
> +	union perf_cached perf;
> +
>  	u8	prefcore_ranking;
> -	u8	min_limit_perf;
> -	u8	max_limit_perf;
>  	u32	min_limit_freq;
>  	u32	max_limit_freq;
>  	u32	nominal_freq;
> -- 
> 2.43.0
> 

[PATCH v2 04/17] cpufreq/amd-pstate: Overhaul locking

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

amd_pstate_cpu_boost_update() and refresh_frequency_limits() both
update the policy state and have nothing to do with the amd-pstate
driver itself.

A global "limits" lock doesn't make sense because each CPU can have
policies changed independently.  Each time a CPU changes values they
will atomically be written to the per-CPU perf member. Drop per CPU
locking cases.

The remaining "global" driver lock is used to ensure that only one
entity can change driver modes at a given time.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 8c3b54030ec56..044091806f14f 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -196,7 +196,6 @@ static inline int get_mode_idx_from_str(const char *str, size_t size)
 	return -EINVAL;
 }
 
-static DEFINE_MUTEX(amd_pstate_limits_lock);
 static DEFINE_MUTEX(amd_pstate_driver_lock);
 
 static u8 msr_get_epp(struct amd_cpudata *cpudata)
@@ -752,7 +751,6 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
 		pr_err("Boost mode is not supported by this processor or SBIOS\n");
 		return -EOPNOTSUPP;
 	}
-	guard(mutex)(&amd_pstate_driver_lock);
 
 	ret = amd_pstate_cpu_boost_update(policy, state);
 	refresh_frequency_limits(policy);
@@ -1172,8 +1170,6 @@ static ssize_t store_energy_performance_preference(
 	if (ret < 0)
 		return -EINVAL;
 
-	guard(mutex)(&amd_pstate_limits_lock);
-
 	ret = amd_pstate_set_energy_pref_index(policy, ret);
 
 	return ret ? ret : count;
@@ -1346,8 +1342,10 @@ int amd_pstate_update_status(const char *buf, size_t size)
 	if (mode_idx < 0 || mode_idx >= AMD_PSTATE_MAX)
 		return -EINVAL;
 
-	if (mode_state_machine[cppc_state][mode_idx])
+	if (mode_state_machine[cppc_state][mode_idx]) {
+		guard(mutex)(&amd_pstate_driver_lock);
 		return mode_state_machine[cppc_state][mode_idx](mode_idx);
+	}
 
 	return 0;
 }
@@ -1368,7 +1366,6 @@ static ssize_t status_store(struct device *a, struct device_attribute *b,
 	char *p = memchr(buf, '\n', count);
 	int ret;
 
-	guard(mutex)(&amd_pstate_driver_lock);
 	ret = amd_pstate_update_status(buf, p ? p - buf : count);
 
 	return ret < 0 ? ret : count;
@@ -1640,8 +1637,6 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 	if (cpudata->suspended)
 		return 0;
 
-	guard(mutex)(&amd_pstate_limits_lock);
-
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
 					  AMD_CPPC_EPP_BALANCE_POWERSAVE,
@@ -1678,8 +1673,6 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
 	struct amd_cpudata *cpudata = policy->driver_data;
 
 	if (cpudata->suspended) {
-		guard(mutex)(&amd_pstate_limits_lock);
-
 		/* enable amd pstate from suspend state*/
 		amd_pstate_epp_reenable(policy);
 
-- 
2.43.0

Re: [PATCH v2 04/17] cpufreq/amd-pstate: Overhaul locking

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:31PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> amd_pstate_cpu_boost_update() and refresh_frequency_limits() both
> update the policy state and have nothing to do with the amd-pstate
> driver itself.
> 
> A global "limits" lock doesn't make sense because each CPU can have
> policies changed independently.  Each time a CPU changes values they
> will atomically be written to the per-CPU perf member. Drop per CPU
> locking cases.
> 
> The remaining "global" driver lock is used to ensure that only one
> entity can change driver modes at a given time.

Yup. The patch looks good to me.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.


> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 13 +++----------
>  1 file changed, 3 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 8c3b54030ec56..044091806f14f 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -196,7 +196,6 @@ static inline int get_mode_idx_from_str(const char *str, size_t size)
>  	return -EINVAL;
>  }
>  
> -static DEFINE_MUTEX(amd_pstate_limits_lock);
>  static DEFINE_MUTEX(amd_pstate_driver_lock);
>  
>  static u8 msr_get_epp(struct amd_cpudata *cpudata)
> @@ -752,7 +751,6 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
>  		pr_err("Boost mode is not supported by this processor or SBIOS\n");
>  		return -EOPNOTSUPP;
>  	}
> -	guard(mutex)(&amd_pstate_driver_lock);
>  
>  	ret = amd_pstate_cpu_boost_update(policy, state);
>  	refresh_frequency_limits(policy);
> @@ -1172,8 +1170,6 @@ static ssize_t store_energy_performance_preference(
>  	if (ret < 0)
>  		return -EINVAL;
>  
> -	guard(mutex)(&amd_pstate_limits_lock);
> -
>  	ret = amd_pstate_set_energy_pref_index(policy, ret);
>  
>  	return ret ? ret : count;
> @@ -1346,8 +1342,10 @@ int amd_pstate_update_status(const char *buf, size_t size)
>  	if (mode_idx < 0 || mode_idx >= AMD_PSTATE_MAX)
>  		return -EINVAL;
>  
> -	if (mode_state_machine[cppc_state][mode_idx])
> +	if (mode_state_machine[cppc_state][mode_idx]) {
> +		guard(mutex)(&amd_pstate_driver_lock);
>  		return mode_state_machine[cppc_state][mode_idx](mode_idx);
> +	}
>  
>  	return 0;
>  }
> @@ -1368,7 +1366,6 @@ static ssize_t status_store(struct device *a, struct device_attribute *b,
>  	char *p = memchr(buf, '\n', count);
>  	int ret;
>  
> -	guard(mutex)(&amd_pstate_driver_lock);
>  	ret = amd_pstate_update_status(buf, p ? p - buf : count);
>  
>  	return ret < 0 ? ret : count;
> @@ -1640,8 +1637,6 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
>  	if (cpudata->suspended)
>  		return 0;
>  
> -	guard(mutex)(&amd_pstate_limits_lock);
> -
>  	if (trace_amd_pstate_epp_perf_enabled()) {
>  		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
>  					  AMD_CPPC_EPP_BALANCE_POWERSAVE,
> @@ -1678,8 +1673,6 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
>  	struct amd_cpudata *cpudata = policy->driver_data;
>  
>  	if (cpudata->suspended) {
> -		guard(mutex)(&amd_pstate_limits_lock);
> -
>  		/* enable amd pstate from suspend state*/
>  		amd_pstate_epp_reenable(policy);
>  
> -- 
> 2.43.0
> 

[PATCH v2 05/17] cpufreq/amd-pstate: Drop `cppc_cap1_cached`

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

The `cppc_cap1_cached` variable isn't used at all, there is no
need to read it at initialization for each CPU.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 5 -----
 drivers/cpufreq/amd-pstate.h | 2 --
 2 files changed, 7 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 044091806f14f..e5983e5c77ba2 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1510,11 +1510,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 		if (ret)
 			return ret;
 		WRITE_ONCE(cpudata->cppc_req_cached, value);
-
-		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &value);
-		if (ret)
-			return ret;
-		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
 	}
 	ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
 	if (ret)
diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
index 8421c83c07919..1a52582dbac9d 100644
--- a/drivers/cpufreq/amd-pstate.h
+++ b/drivers/cpufreq/amd-pstate.h
@@ -74,7 +74,6 @@ struct amd_aperf_mperf {
  * 		  AMD P-State driver supports preferred core featue.
  * @epp_cached: Cached CPPC energy-performance preference value
  * @policy: Cpufreq policy value
- * @cppc_cap1_cached Cached MSR_AMD_CPPC_CAP1 register value
  *
  * The amd_cpudata is key private data for each CPU thread in AMD P-State, and
  * represents all the attributes and goals that AMD P-State requests at runtime.
@@ -103,7 +102,6 @@ struct amd_cpudata {
 	/* EPP feature related attributes*/
 	u8	epp_cached;
 	u32	policy;
-	u64	cppc_cap1_cached;
 	bool	suspended;
 	u8	epp_default;
 };
-- 
2.43.0

Re: [PATCH v2 05/17] cpufreq/amd-pstate: Drop `cppc_cap1_cached`

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:32PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> The `cppc_cap1_cached` variable isn't used at all, there is no
> need to read it at initialization for each CPU.
> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Thanks for this cleanup.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.


> ---
>  drivers/cpufreq/amd-pstate.c | 5 -----
>  drivers/cpufreq/amd-pstate.h | 2 --
>  2 files changed, 7 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 044091806f14f..e5983e5c77ba2 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1510,11 +1510,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  		if (ret)
>  			return ret;
>  		WRITE_ONCE(cpudata->cppc_req_cached, value);
> -
> -		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &value);
> -		if (ret)
> -			return ret;
> -		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
>  	}
>  	ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
>  	if (ret)
> diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
> index 8421c83c07919..1a52582dbac9d 100644
> --- a/drivers/cpufreq/amd-pstate.h
> +++ b/drivers/cpufreq/amd-pstate.h
> @@ -74,7 +74,6 @@ struct amd_aperf_mperf {
>   * 		  AMD P-State driver supports preferred core featue.
>   * @epp_cached: Cached CPPC energy-performance preference value
>   * @policy: Cpufreq policy value
> - * @cppc_cap1_cached Cached MSR_AMD_CPPC_CAP1 register value
>   *
>   * The amd_cpudata is key private data for each CPU thread in AMD P-State, and
>   * represents all the attributes and goals that AMD P-State requests at runtime.
> @@ -103,7 +102,6 @@ struct amd_cpudata {
>  	/* EPP feature related attributes*/
>  	u8	epp_cached;
>  	u32	policy;
> -	u64	cppc_cap1_cached;
>  	bool	suspended;
>  	u8	epp_default;
>  };
> -- 
> 2.43.0
> 

[PATCH v2 06/17] cpufreq/amd-pstate-ut: Use _free macro to free put policy

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

Using a scoped cleanup macro simplifies cleanup code.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate-ut.c | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index ba3e06f349c6d..9f790c7254d52 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/fs.h>
+#include <linux/cleanup.h>
 
 #include <acpi/cppc_acpi.h>
 
@@ -127,11 +128,12 @@ static void amd_pstate_ut_check_perf(u32 index)
 	u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
 	u64 cap1 = 0;
 	struct cppc_perf_caps cppc_perf;
-	struct cpufreq_policy *policy = NULL;
 	struct amd_cpudata *cpudata = NULL;
 	union perf_cached cur_perf;
 
 	for_each_possible_cpu(cpu) {
+		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
+
 		policy = cpufreq_cpu_get(cpu);
 		if (!policy)
 			break;
@@ -142,7 +144,7 @@ static void amd_pstate_ut_check_perf(u32 index)
 			if (ret) {
 				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 				pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
-				goto skip_test;
+				return;
 			}
 
 			highest_perf = cppc_perf.highest_perf;
@@ -154,7 +156,7 @@ static void amd_pstate_ut_check_perf(u32 index)
 			if (ret) {
 				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 				pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
-				goto skip_test;
+				return;
 			}
 
 			highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
@@ -167,7 +169,7 @@ static void amd_pstate_ut_check_perf(u32 index)
 		if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
 			pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
 				__func__, cpu, highest_perf, cpudata->perf.highest_perf);
-			goto skip_test;
+			return;
 		}
 		if (nominal_perf != cur_perf.nominal_perf ||
 		   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
@@ -177,7 +179,7 @@ static void amd_pstate_ut_check_perf(u32 index)
 				__func__, cpu, nominal_perf, cpudata->perf.nominal_perf,
 				lowest_nonlinear_perf, cpudata->perf.lowest_nonlinear_perf,
 				lowest_perf, cpudata->perf.lowest_perf);
-			goto skip_test;
+			return;
 		}
 
 		if (!((highest_perf >= nominal_perf) &&
@@ -188,15 +190,11 @@ static void amd_pstate_ut_check_perf(u32 index)
 			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
 				__func__, cpu, highest_perf, nominal_perf,
 				lowest_nonlinear_perf, lowest_perf);
-			goto skip_test;
+			return;
 		}
-		cpufreq_cpu_put(policy);
 	}
 
 	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
-	return;
-skip_test:
-	cpufreq_cpu_put(policy);
 }
 
 /*
@@ -207,10 +205,11 @@ static void amd_pstate_ut_check_perf(u32 index)
 static void amd_pstate_ut_check_freq(u32 index)
 {
 	int cpu = 0;
-	struct cpufreq_policy *policy = NULL;
 	struct amd_cpudata *cpudata = NULL;
 
 	for_each_possible_cpu(cpu) {
+		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
+
 		policy = cpufreq_cpu_get(cpu);
 		if (!policy)
 			break;
@@ -224,14 +223,14 @@ static void amd_pstate_ut_check_freq(u32 index)
 			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
 				__func__, cpu, policy->cpuinfo.max_freq, cpudata->nominal_freq,
 				cpudata->lowest_nonlinear_freq, policy->cpuinfo.min_freq);
-			goto skip_test;
+			return;
 		}
 
 		if (cpudata->lowest_nonlinear_freq != policy->min) {
 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d cpudata_lowest_nonlinear_freq=%d policy_min=%d, they should be equal!\n",
 				__func__, cpu, cpudata->lowest_nonlinear_freq, policy->min);
-			goto skip_test;
+			return;
 		}
 
 		if (cpudata->boost_supported) {
@@ -243,20 +242,16 @@ static void amd_pstate_ut_check_freq(u32 index)
 				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
 					__func__, cpu, policy->max, policy->cpuinfo.max_freq,
 					cpudata->nominal_freq);
-				goto skip_test;
+				return;
 			}
 		} else {
 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d must support boost!\n", __func__, cpu);
-			goto skip_test;
+			return;
 		}
-		cpufreq_cpu_put(policy);
 	}
 
 	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
-	return;
-skip_test:
-	cpufreq_cpu_put(policy);
 }
 
 static int amd_pstate_set_mode(enum amd_pstate_mode mode)
-- 
2.43.0

Re: [PATCH v2 06/17] cpufreq/amd-pstate-ut: Use _free macro to free put policy

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:33PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> Using a scoped cleanup macro simplifies cleanup code.
> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

LGTM.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.

> ---
>  drivers/cpufreq/amd-pstate-ut.c | 33 ++++++++++++++-------------------
>  1 file changed, 14 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index ba3e06f349c6d..9f790c7254d52 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -26,6 +26,7 @@
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
>  #include <linux/fs.h>
> +#include <linux/cleanup.h>
>  
>  #include <acpi/cppc_acpi.h>
>  
> @@ -127,11 +128,12 @@ static void amd_pstate_ut_check_perf(u32 index)
>  	u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
>  	u64 cap1 = 0;
>  	struct cppc_perf_caps cppc_perf;
> -	struct cpufreq_policy *policy = NULL;
>  	struct amd_cpudata *cpudata = NULL;
>  	union perf_cached cur_perf;
>  
>  	for_each_possible_cpu(cpu) {
> +		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
> +
>  		policy = cpufreq_cpu_get(cpu);
>  		if (!policy)
>  			break;
> @@ -142,7 +144,7 @@ static void amd_pstate_ut_check_perf(u32 index)
>  			if (ret) {
>  				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  				pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
> -				goto skip_test;
> +				return;
>  			}
>  
>  			highest_perf = cppc_perf.highest_perf;
> @@ -154,7 +156,7 @@ static void amd_pstate_ut_check_perf(u32 index)
>  			if (ret) {
>  				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  				pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
> -				goto skip_test;
> +				return;
>  			}
>  
>  			highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
> @@ -167,7 +169,7 @@ static void amd_pstate_ut_check_perf(u32 index)
>  		if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
>  			pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
>  				__func__, cpu, highest_perf, cpudata->perf.highest_perf);
> -			goto skip_test;
> +			return;
>  		}
>  		if (nominal_perf != cur_perf.nominal_perf ||
>  		   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
> @@ -177,7 +179,7 @@ static void amd_pstate_ut_check_perf(u32 index)
>  				__func__, cpu, nominal_perf, cpudata->perf.nominal_perf,
>  				lowest_nonlinear_perf, cpudata->perf.lowest_nonlinear_perf,
>  				lowest_perf, cpudata->perf.lowest_perf);
> -			goto skip_test;
> +			return;
>  		}
>  
>  		if (!((highest_perf >= nominal_perf) &&
> @@ -188,15 +190,11 @@ static void amd_pstate_ut_check_perf(u32 index)
>  			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
>  				__func__, cpu, highest_perf, nominal_perf,
>  				lowest_nonlinear_perf, lowest_perf);
> -			goto skip_test;
> +			return;
>  		}
> -		cpufreq_cpu_put(policy);
>  	}
>  
>  	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> -	return;
> -skip_test:
> -	cpufreq_cpu_put(policy);
>  }
>  
>  /*
> @@ -207,10 +205,11 @@ static void amd_pstate_ut_check_perf(u32 index)
>  static void amd_pstate_ut_check_freq(u32 index)
>  {
>  	int cpu = 0;
> -	struct cpufreq_policy *policy = NULL;
>  	struct amd_cpudata *cpudata = NULL;
>  
>  	for_each_possible_cpu(cpu) {
> +		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
> +
>  		policy = cpufreq_cpu_get(cpu);
>  		if (!policy)
>  			break;
> @@ -224,14 +223,14 @@ static void amd_pstate_ut_check_freq(u32 index)
>  			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
>  				__func__, cpu, policy->cpuinfo.max_freq, cpudata->nominal_freq,
>  				cpudata->lowest_nonlinear_freq, policy->cpuinfo.min_freq);
> -			goto skip_test;
> +			return;
>  		}
>  
>  		if (cpudata->lowest_nonlinear_freq != policy->min) {
>  			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d cpudata_lowest_nonlinear_freq=%d policy_min=%d, they should be equal!\n",
>  				__func__, cpu, cpudata->lowest_nonlinear_freq, policy->min);
> -			goto skip_test;
> +			return;
>  		}
>  
>  		if (cpudata->boost_supported) {
> @@ -243,20 +242,16 @@ static void amd_pstate_ut_check_freq(u32 index)
>  				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
>  					__func__, cpu, policy->max, policy->cpuinfo.max_freq,
>  					cpudata->nominal_freq);
> -				goto skip_test;
> +				return;
>  			}
>  		} else {
>  			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d must support boost!\n", __func__, cpu);
> -			goto skip_test;
> +			return;
>  		}
> -		cpufreq_cpu_put(policy);
>  	}
>  
>  	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> -	return;
> -skip_test:
> -	cpufreq_cpu_put(policy);
>  }
>  
>  static int amd_pstate_set_mode(enum amd_pstate_mode mode)
> -- 
> 2.43.0
> 

[PATCH v2 07/17] cpufreq/amd-pstate-ut: Allow lowest nonlinear and lowest to be the same

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

Several Ryzen AI processors support the exact same value for lowest
nonlinear perf and lowest perf.  Loosen up the unit tests to allow this
scenario.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * New patch

 drivers/cpufreq/amd-pstate-ut.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index 9f790c7254d52..0f0b867e271cc 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -184,7 +184,7 @@ static void amd_pstate_ut_check_perf(u32 index)
 
 		if (!((highest_perf >= nominal_perf) &&
 			(nominal_perf > lowest_nonlinear_perf) &&
-			(lowest_nonlinear_perf > lowest_perf) &&
+			(lowest_nonlinear_perf >= lowest_perf) &&
 			(lowest_perf > 0))) {
 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
@@ -217,7 +217,7 @@ static void amd_pstate_ut_check_freq(u32 index)
 
 		if (!((policy->cpuinfo.max_freq >= cpudata->nominal_freq) &&
 			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
-			(cpudata->lowest_nonlinear_freq > policy->cpuinfo.min_freq) &&
+			(cpudata->lowest_nonlinear_freq >= policy->cpuinfo.min_freq) &&
 			(policy->cpuinfo.min_freq > 0))) {
 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
-- 
2.43.0

Re: [PATCH v2 07/17] cpufreq/amd-pstate-ut: Allow lowest nonlinear and lowest to be the same

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:34PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> Several Ryzen AI processors support the exact same value for lowest
> nonlinear perf and lowest perf.  Loosen up the unit tests to allow this
> scenario.

LGTM

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.

> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2:
>  * New patch
> 
>  drivers/cpufreq/amd-pstate-ut.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index 9f790c7254d52..0f0b867e271cc 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -184,7 +184,7 @@ static void amd_pstate_ut_check_perf(u32 index)
>  
>  		if (!((highest_perf >= nominal_perf) &&
>  			(nominal_perf > lowest_nonlinear_perf) &&
> -			(lowest_nonlinear_perf > lowest_perf) &&
> +			(lowest_nonlinear_perf >= lowest_perf) &&
>  			(lowest_perf > 0))) {
>  			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
> @@ -217,7 +217,7 @@ static void amd_pstate_ut_check_freq(u32 index)
>  
>  		if (!((policy->cpuinfo.max_freq >= cpudata->nominal_freq) &&
>  			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
> -			(cpudata->lowest_nonlinear_freq > policy->cpuinfo.min_freq) &&
> +			(cpudata->lowest_nonlinear_freq >= policy->cpuinfo.min_freq) &&
>  			(policy->cpuinfo.min_freq > 0))) {
>  			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
> -- 
> 2.43.0
> 

[PATCH v2 08/17] cpufreq/amd-pstate-ut: Drop SUCCESS and FAIL enums

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

Enums are effectively used as a boolean and don't show
the return value of the failing call.

Instead of using enums switch to returning the actual return
code from the unit test.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * new patch

 drivers/cpufreq/amd-pstate-ut.c | 143 ++++++++++++--------------------
 1 file changed, 55 insertions(+), 88 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index 0f0b867e271cc..028527a0019ca 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -32,30 +32,20 @@
 
 #include "amd-pstate.h"
 
-/*
- * Abbreviations:
- * amd_pstate_ut: used as a shortform for AMD P-State unit test.
- * It helps to keep variable names smaller, simpler
- */
-enum amd_pstate_ut_result {
-	AMD_PSTATE_UT_RESULT_PASS,
-	AMD_PSTATE_UT_RESULT_FAIL,
-};
 
 struct amd_pstate_ut_struct {
 	const char *name;
-	void (*func)(u32 index);
-	enum amd_pstate_ut_result result;
+	int (*func)(u32 index);
 };
 
 /*
  * Kernel module for testing the AMD P-State unit test
  */
-static void amd_pstate_ut_acpi_cpc_valid(u32 index);
-static void amd_pstate_ut_check_enabled(u32 index);
-static void amd_pstate_ut_check_perf(u32 index);
-static void amd_pstate_ut_check_freq(u32 index);
-static void amd_pstate_ut_check_driver(u32 index);
+static int amd_pstate_ut_acpi_cpc_valid(u32 index);
+static int amd_pstate_ut_check_enabled(u32 index);
+static int amd_pstate_ut_check_perf(u32 index);
+static int amd_pstate_ut_check_freq(u32 index);
+static int amd_pstate_ut_check_driver(u32 index);
 
 static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = {
 	{"amd_pstate_ut_acpi_cpc_valid",   amd_pstate_ut_acpi_cpc_valid   },
@@ -78,51 +68,46 @@ static bool get_shared_mem(void)
 /*
  * check the _CPC object is present in SBIOS.
  */
-static void amd_pstate_ut_acpi_cpc_valid(u32 index)
+static int amd_pstate_ut_acpi_cpc_valid(u32 index)
 {
-	if (acpi_cpc_valid())
-		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
-	else {
-		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
+	if (!acpi_cpc_valid()) {
 		pr_err("%s the _CPC object is not present in SBIOS!\n", __func__);
+		return -EINVAL;
 	}
+
+	return 0;
 }
 
-static void amd_pstate_ut_pstate_enable(u32 index)
+/*
+ * check if amd pstate is enabled
+ */
+static int amd_pstate_ut_check_enabled(u32 index)
 {
-	int ret = 0;
 	u64 cppc_enable = 0;
+	int ret;
+
+	if (get_shared_mem())
+		return 0;
 
 	ret = rdmsrl_safe(MSR_AMD_CPPC_ENABLE, &cppc_enable);
 	if (ret) {
-		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 		pr_err("%s rdmsrl_safe MSR_AMD_CPPC_ENABLE ret=%d error!\n", __func__, ret);
-		return;
+		return ret;
 	}
-	if (cppc_enable)
-		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
-	else {
-		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
+
+	if (!cppc_enable) {
 		pr_err("%s amd pstate must be enabled!\n", __func__);
+		return -EINVAL;
 	}
-}
 
-/*
- * check if amd pstate is enabled
- */
-static void amd_pstate_ut_check_enabled(u32 index)
-{
-	if (get_shared_mem())
-		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
-	else
-		amd_pstate_ut_pstate_enable(index);
+	return 0;
 }
 
 /*
  * check if performance values are reasonable.
  * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0
  */
-static void amd_pstate_ut_check_perf(u32 index)
+static int amd_pstate_ut_check_perf(u32 index)
 {
 	int cpu = 0, ret = 0;
 	u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
@@ -142,9 +127,8 @@ static void amd_pstate_ut_check_perf(u32 index)
 		if (get_shared_mem()) {
 			ret = cppc_get_perf_caps(cpu, &cppc_perf);
 			if (ret) {
-				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 				pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
-				return;
+				return ret;
 			}
 
 			highest_perf = cppc_perf.highest_perf;
@@ -154,9 +138,8 @@ static void amd_pstate_ut_check_perf(u32 index)
 		} else {
 			ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
 			if (ret) {
-				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 				pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
-				return;
+				return ret;
 			}
 
 			highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
@@ -169,32 +152,30 @@ static void amd_pstate_ut_check_perf(u32 index)
 		if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
 			pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
 				__func__, cpu, highest_perf, cpudata->perf.highest_perf);
-			return;
+			return -EINVAL;
 		}
 		if (nominal_perf != cur_perf.nominal_perf ||
 		   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
 		   (lowest_perf != cur_perf.lowest_perf)) {
-			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
 				__func__, cpu, nominal_perf, cpudata->perf.nominal_perf,
 				lowest_nonlinear_perf, cpudata->perf.lowest_nonlinear_perf,
 				lowest_perf, cpudata->perf.lowest_perf);
-			return;
+			return -EINVAL;
 		}
 
 		if (!((highest_perf >= nominal_perf) &&
 			(nominal_perf > lowest_nonlinear_perf) &&
 			(lowest_nonlinear_perf >= lowest_perf) &&
 			(lowest_perf > 0))) {
-			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
 				__func__, cpu, highest_perf, nominal_perf,
 				lowest_nonlinear_perf, lowest_perf);
-			return;
+			return -EINVAL;
 		}
 	}
 
-	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
+	return 0;
 }
 
 /*
@@ -202,7 +183,7 @@ static void amd_pstate_ut_check_perf(u32 index)
  * max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0
  * check max freq when set support boost mode.
  */
-static void amd_pstate_ut_check_freq(u32 index)
+static int amd_pstate_ut_check_freq(u32 index)
 {
 	int cpu = 0;
 	struct amd_cpudata *cpudata = NULL;
@@ -219,39 +200,33 @@ static void amd_pstate_ut_check_freq(u32 index)
 			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
 			(cpudata->lowest_nonlinear_freq >= policy->cpuinfo.min_freq) &&
 			(policy->cpuinfo.min_freq > 0))) {
-			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
 				__func__, cpu, policy->cpuinfo.max_freq, cpudata->nominal_freq,
 				cpudata->lowest_nonlinear_freq, policy->cpuinfo.min_freq);
-			return;
+			return -EINVAL;
 		}
 
 		if (cpudata->lowest_nonlinear_freq != policy->min) {
-			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d cpudata_lowest_nonlinear_freq=%d policy_min=%d, they should be equal!\n",
 				__func__, cpu, cpudata->lowest_nonlinear_freq, policy->min);
-			return;
+			return -EINVAL;
 		}
 
 		if (cpudata->boost_supported) {
-			if ((policy->max == policy->cpuinfo.max_freq) ||
-					(policy->max == cpudata->nominal_freq))
-				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
-			else {
-				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
+			if ((policy->max != policy->cpuinfo.max_freq) &&
+			    (policy->max != cpudata->nominal_freq)) {
 				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
 					__func__, cpu, policy->max, policy->cpuinfo.max_freq,
 					cpudata->nominal_freq);
-				return;
+				return -EINVAL;
 			}
 		} else {
-			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 			pr_err("%s cpu%d must support boost!\n", __func__, cpu);
-			return;
+			return -EINVAL;
 		}
 	}
 
-	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
+	return 0;
 }
 
 static int amd_pstate_set_mode(enum amd_pstate_mode mode)
@@ -263,32 +238,28 @@ static int amd_pstate_set_mode(enum amd_pstate_mode mode)
 	return amd_pstate_update_status(mode_str, strlen(mode_str));
 }
 
-static void amd_pstate_ut_check_driver(u32 index)
+static int amd_pstate_ut_check_driver(u32 index)
 {
 	enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;
-	int ret;
 
 	for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) {
-		ret = amd_pstate_set_mode(mode1);
+		int ret = amd_pstate_set_mode(mode1);
 		if (ret)
-			goto out;
+			return ret;
 		for (mode2 = AMD_PSTATE_DISABLE; mode2 < AMD_PSTATE_MAX; mode2++) {
 			if (mode1 == mode2)
 				continue;
 			ret = amd_pstate_set_mode(mode2);
-			if (ret)
-				goto out;
+			if (ret) {
+				pr_err("%s: failed to update status for %s->%s\n", __func__,
+					amd_pstate_get_mode_string(mode1),
+					amd_pstate_get_mode_string(mode2));
+				return ret;
+			}
 		}
 	}
-out:
-	if (ret)
-		pr_warn("%s: failed to update status for %s->%s: %d\n", __func__,
-			amd_pstate_get_mode_string(mode1),
-			amd_pstate_get_mode_string(mode2), ret);
-
-	amd_pstate_ut_cases[index].result = ret ?
-					    AMD_PSTATE_UT_RESULT_FAIL :
-					    AMD_PSTATE_UT_RESULT_PASS;
+
+	return 0;
 }
 
 static int __init amd_pstate_ut_init(void)
@@ -296,16 +267,12 @@ static int __init amd_pstate_ut_init(void)
 	u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases);
 
 	for (i = 0; i < arr_size; i++) {
-		amd_pstate_ut_cases[i].func(i);
-		switch (amd_pstate_ut_cases[i].result) {
-		case AMD_PSTATE_UT_RESULT_PASS:
+		int ret = amd_pstate_ut_cases[i].func(i);
+
+		if (ret)
+			pr_err("%-4d %-20s\t fail: %d!\n", i+1, amd_pstate_ut_cases[i].name, ret);
+		else
 			pr_info("%-4d %-20s\t success!\n", i+1, amd_pstate_ut_cases[i].name);
-			break;
-		case AMD_PSTATE_UT_RESULT_FAIL:
-		default:
-			pr_info("%-4d %-20s\t fail!\n", i+1, amd_pstate_ut_cases[i].name);
-			break;
-		}
 	}
 
 	return 0;
-- 
2.43.0

Re: [PATCH v2 08/17] cpufreq/amd-pstate-ut: Drop SUCCESS and FAIL enums

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:35PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> Enums are effectively used as a boolean and don't show
> the return value of the failing call.
> 
> Instead of using enums switch to returning the actual return
> code from the unit test.

Yeah, having the failure code in the error message is helpful.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.

> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2:
>  * new patch
> 
>  drivers/cpufreq/amd-pstate-ut.c | 143 ++++++++++++--------------------
>  1 file changed, 55 insertions(+), 88 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index 0f0b867e271cc..028527a0019ca 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -32,30 +32,20 @@
>  
>  #include "amd-pstate.h"
>  
> -/*
> - * Abbreviations:
> - * amd_pstate_ut: used as a shortform for AMD P-State unit test.
> - * It helps to keep variable names smaller, simpler
> - */
> -enum amd_pstate_ut_result {
> -	AMD_PSTATE_UT_RESULT_PASS,
> -	AMD_PSTATE_UT_RESULT_FAIL,
> -};
>  
>  struct amd_pstate_ut_struct {
>  	const char *name;
> -	void (*func)(u32 index);
> -	enum amd_pstate_ut_result result;
> +	int (*func)(u32 index);
>  };
>  
>  /*
>   * Kernel module for testing the AMD P-State unit test
>   */
> -static void amd_pstate_ut_acpi_cpc_valid(u32 index);
> -static void amd_pstate_ut_check_enabled(u32 index);
> -static void amd_pstate_ut_check_perf(u32 index);
> -static void amd_pstate_ut_check_freq(u32 index);
> -static void amd_pstate_ut_check_driver(u32 index);
> +static int amd_pstate_ut_acpi_cpc_valid(u32 index);
> +static int amd_pstate_ut_check_enabled(u32 index);
> +static int amd_pstate_ut_check_perf(u32 index);
> +static int amd_pstate_ut_check_freq(u32 index);
> +static int amd_pstate_ut_check_driver(u32 index);
>  
>  static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = {
>  	{"amd_pstate_ut_acpi_cpc_valid",   amd_pstate_ut_acpi_cpc_valid   },
> @@ -78,51 +68,46 @@ static bool get_shared_mem(void)
>  /*
>   * check the _CPC object is present in SBIOS.
>   */
> -static void amd_pstate_ut_acpi_cpc_valid(u32 index)
> +static int amd_pstate_ut_acpi_cpc_valid(u32 index)
>  {
> -	if (acpi_cpc_valid())
> -		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> -	else {
> -		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
> +	if (!acpi_cpc_valid()) {
>  		pr_err("%s the _CPC object is not present in SBIOS!\n", __func__);
> +		return -EINVAL;
>  	}
> +
> +	return 0;
>  }
>  
> -static void amd_pstate_ut_pstate_enable(u32 index)
> +/*
> + * check if amd pstate is enabled
> + */
> +static int amd_pstate_ut_check_enabled(u32 index)
>  {
> -	int ret = 0;
>  	u64 cppc_enable = 0;
> +	int ret;
> +
> +	if (get_shared_mem())
> +		return 0;
>  
>  	ret = rdmsrl_safe(MSR_AMD_CPPC_ENABLE, &cppc_enable);
>  	if (ret) {
> -		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  		pr_err("%s rdmsrl_safe MSR_AMD_CPPC_ENABLE ret=%d error!\n", __func__, ret);
> -		return;
> +		return ret;
>  	}
> -	if (cppc_enable)
> -		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> -	else {
> -		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
> +
> +	if (!cppc_enable) {
>  		pr_err("%s amd pstate must be enabled!\n", __func__);
> +		return -EINVAL;
>  	}
> -}
>  
> -/*
> - * check if amd pstate is enabled
> - */
> -static void amd_pstate_ut_check_enabled(u32 index)
> -{
> -	if (get_shared_mem())
> -		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> -	else
> -		amd_pstate_ut_pstate_enable(index);
> +	return 0;
>  }
>  
>  /*
>   * check if performance values are reasonable.
>   * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0
>   */
> -static void amd_pstate_ut_check_perf(u32 index)
> +static int amd_pstate_ut_check_perf(u32 index)
>  {
>  	int cpu = 0, ret = 0;
>  	u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
> @@ -142,9 +127,8 @@ static void amd_pstate_ut_check_perf(u32 index)
>  		if (get_shared_mem()) {
>  			ret = cppc_get_perf_caps(cpu, &cppc_perf);
>  			if (ret) {
> -				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  				pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
> -				return;
> +				return ret;
>  			}
>  
>  			highest_perf = cppc_perf.highest_perf;
> @@ -154,9 +138,8 @@ static void amd_pstate_ut_check_perf(u32 index)
>  		} else {
>  			ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
>  			if (ret) {
> -				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  				pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
> -				return;
> +				return ret;
>  			}
>  
>  			highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
> @@ -169,32 +152,30 @@ static void amd_pstate_ut_check_perf(u32 index)
>  		if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
>  			pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
>  				__func__, cpu, highest_perf, cpudata->perf.highest_perf);
> -			return;
> +			return -EINVAL;
>  		}
>  		if (nominal_perf != cur_perf.nominal_perf ||
>  		   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
>  		   (lowest_perf != cur_perf.lowest_perf)) {
> -			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
>  				__func__, cpu, nominal_perf, cpudata->perf.nominal_perf,
>  				lowest_nonlinear_perf, cpudata->perf.lowest_nonlinear_perf,
>  				lowest_perf, cpudata->perf.lowest_perf);
> -			return;
> +			return -EINVAL;
>  		}
>  
>  		if (!((highest_perf >= nominal_perf) &&
>  			(nominal_perf > lowest_nonlinear_perf) &&
>  			(lowest_nonlinear_perf >= lowest_perf) &&
>  			(lowest_perf > 0))) {
> -			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
>  				__func__, cpu, highest_perf, nominal_perf,
>  				lowest_nonlinear_perf, lowest_perf);
> -			return;
> +			return -EINVAL;
>  		}
>  	}
>  
> -	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> +	return 0;
>  }
>  
>  /*
> @@ -202,7 +183,7 @@ static void amd_pstate_ut_check_perf(u32 index)
>   * max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0
>   * check max freq when set support boost mode.
>   */
> -static void amd_pstate_ut_check_freq(u32 index)
> +static int amd_pstate_ut_check_freq(u32 index)
>  {
>  	int cpu = 0;
>  	struct amd_cpudata *cpudata = NULL;
> @@ -219,39 +200,33 @@ static void amd_pstate_ut_check_freq(u32 index)
>  			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
>  			(cpudata->lowest_nonlinear_freq >= policy->cpuinfo.min_freq) &&
>  			(policy->cpuinfo.min_freq > 0))) {
> -			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
>  				__func__, cpu, policy->cpuinfo.max_freq, cpudata->nominal_freq,
>  				cpudata->lowest_nonlinear_freq, policy->cpuinfo.min_freq);
> -			return;
> +			return -EINVAL;
>  		}
>  
>  		if (cpudata->lowest_nonlinear_freq != policy->min) {
> -			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d cpudata_lowest_nonlinear_freq=%d policy_min=%d, they should be equal!\n",
>  				__func__, cpu, cpudata->lowest_nonlinear_freq, policy->min);
> -			return;
> +			return -EINVAL;
>  		}
>  
>  		if (cpudata->boost_supported) {
> -			if ((policy->max == policy->cpuinfo.max_freq) ||
> -					(policy->max == cpudata->nominal_freq))
> -				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> -			else {
> -				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
> +			if ((policy->max != policy->cpuinfo.max_freq) &&
> +			    (policy->max != cpudata->nominal_freq)) {
>  				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
>  					__func__, cpu, policy->max, policy->cpuinfo.max_freq,
>  					cpudata->nominal_freq);
> -				return;
> +				return -EINVAL;
>  			}
>  		} else {
> -			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
>  			pr_err("%s cpu%d must support boost!\n", __func__, cpu);
> -			return;
> +			return -EINVAL;
>  		}
>  	}
>  
> -	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
> +	return 0;
>  }
>  
>  static int amd_pstate_set_mode(enum amd_pstate_mode mode)
> @@ -263,32 +238,28 @@ static int amd_pstate_set_mode(enum amd_pstate_mode mode)
>  	return amd_pstate_update_status(mode_str, strlen(mode_str));
>  }
>  
> -static void amd_pstate_ut_check_driver(u32 index)
> +static int amd_pstate_ut_check_driver(u32 index)
>  {
>  	enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;
> -	int ret;
>  
>  	for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) {
> -		ret = amd_pstate_set_mode(mode1);
> +		int ret = amd_pstate_set_mode(mode1);
>  		if (ret)
> -			goto out;
> +			return ret;
>  		for (mode2 = AMD_PSTATE_DISABLE; mode2 < AMD_PSTATE_MAX; mode2++) {
>  			if (mode1 == mode2)
>  				continue;
>  			ret = amd_pstate_set_mode(mode2);
> -			if (ret)
> -				goto out;
> +			if (ret) {
> +				pr_err("%s: failed to update status for %s->%s\n", __func__,
> +					amd_pstate_get_mode_string(mode1),
> +					amd_pstate_get_mode_string(mode2));
> +				return ret;
> +			}
>  		}
>  	}
> -out:
> -	if (ret)
> -		pr_warn("%s: failed to update status for %s->%s: %d\n", __func__,
> -			amd_pstate_get_mode_string(mode1),
> -			amd_pstate_get_mode_string(mode2), ret);
> -
> -	amd_pstate_ut_cases[index].result = ret ?
> -					    AMD_PSTATE_UT_RESULT_FAIL :
> -					    AMD_PSTATE_UT_RESULT_PASS;
> +
> +	return 0;
>  }
>  
>  static int __init amd_pstate_ut_init(void)
> @@ -296,16 +267,12 @@ static int __init amd_pstate_ut_init(void)
>  	u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases);
>  
>  	for (i = 0; i < arr_size; i++) {
> -		amd_pstate_ut_cases[i].func(i);
> -		switch (amd_pstate_ut_cases[i].result) {
> -		case AMD_PSTATE_UT_RESULT_PASS:
> +		int ret = amd_pstate_ut_cases[i].func(i);
> +
> +		if (ret)
> +			pr_err("%-4d %-20s\t fail: %d!\n", i+1, amd_pstate_ut_cases[i].name, ret);
> +		else
>  			pr_info("%-4d %-20s\t success!\n", i+1, amd_pstate_ut_cases[i].name);
> -			break;
> -		case AMD_PSTATE_UT_RESULT_FAIL:
> -		default:
> -			pr_info("%-4d %-20s\t fail!\n", i+1, amd_pstate_ut_cases[i].name);
> -			break;
> -		}
>  	}
>  
>  	return 0;
> -- 
> 2.43.0
> 

[PATCH v2 09/17] cpufreq/amd-pstate-ut: Continue on missing policies

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

If a CPU is missing a policy then the unit test is skipped for the rest
of the CPUs on the system.

Instead just skip the rest of that test and continue to test the rest
of them.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * new patch

 drivers/cpufreq/amd-pstate-ut.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index 028527a0019ca..b888a5877ad93 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -121,7 +121,7 @@ static int amd_pstate_ut_check_perf(u32 index)
 
 		policy = cpufreq_cpu_get(cpu);
 		if (!policy)
-			break;
+			continue;
 		cpudata = policy->driver_data;
 
 		if (get_shared_mem()) {
@@ -193,7 +193,7 @@ static int amd_pstate_ut_check_freq(u32 index)
 
 		policy = cpufreq_cpu_get(cpu);
 		if (!policy)
-			break;
+			continue;
 		cpudata = policy->driver_data;
 
 		if (!((policy->cpuinfo.max_freq >= cpudata->nominal_freq) &&
-- 
2.43.0

Re: [PATCH v2 09/17] cpufreq/amd-pstate-ut: Continue on missing policies

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:36PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> If a CPU is missing a policy then the unit test is skipped for the rest
> of the CPUs on the system.
> 
> Instead just skip the rest of that test and continue to test the rest
> of them.

Along with this change, does it make sense to only loop over the
online CPUs instead of possible CPUs ?


-- 
Thanks and Regards
gautham.




> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2:
>  * new patch
> 
>  drivers/cpufreq/amd-pstate-ut.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index 028527a0019ca..b888a5877ad93 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -121,7 +121,7 @@ static int amd_pstate_ut_check_perf(u32 index)
>  
>  		policy = cpufreq_cpu_get(cpu);
>  		if (!policy)
> -			break;
> +			continue;
>  		cpudata = policy->driver_data;
>  
>  		if (get_shared_mem()) {
> @@ -193,7 +193,7 @@ static int amd_pstate_ut_check_freq(u32 index)
>  
>  		policy = cpufreq_cpu_get(cpu);
>  		if (!policy)
> -			break;
> +			continue;
>  		cpudata = policy->driver_data;
>  
>  		if (!((policy->cpuinfo.max_freq >= cpudata->nominal_freq) &&
> -- 
> 2.43.0
> 

Re: [PATCH v2 09/17] cpufreq/amd-pstate-ut: Continue on missing policies

[Mario Limonciello]

On 2/17/2025 05:38, Gautham R. Shenoy wrote:
> On Fri, Feb 14, 2025 at 06:52:36PM -0600, Mario Limonciello wrote:
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> If a CPU is missing a policy then the unit test is skipped for the rest
>> of the CPUs on the system.
>>
>> Instead just skip the rest of that test and continue to test the rest
>> of them.
> 
> Along with this change, does it make sense to only loop over the
> online CPUs instead of possible CPUs ?
> 
> 

Sure thing.  Will change this patch for v3.

Thanks!

[PATCH v2 10/17] cpufreq/amd-pstate-ut: Adjust variable scope for amd_pstate_ut_check_freq()

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

The cpudata variable is only needed in the scope of the for loop. Move it
there.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * new patch

 drivers/cpufreq/amd-pstate-ut.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index b888a5877ad93..9db20ac357042 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -186,10 +186,10 @@ static int amd_pstate_ut_check_perf(u32 index)
 static int amd_pstate_ut_check_freq(u32 index)
 {
 	int cpu = 0;
-	struct amd_cpudata *cpudata = NULL;
 
 	for_each_possible_cpu(cpu) {
 		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
+		struct amd_cpudata *cpudata;
 
 		policy = cpufreq_cpu_get(cpu);
 		if (!policy)
-- 
2.43.0

Re: [PATCH v2 10/17] cpufreq/amd-pstate-ut: Adjust variable scope for amd_pstate_ut_check_freq()

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:37PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> The cpudata variable is only needed in the scope of the for loop. Move it
> there.

Makes sense.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2:
>  * new patch
> 
>  drivers/cpufreq/amd-pstate-ut.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index b888a5877ad93..9db20ac357042 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -186,10 +186,10 @@ static int amd_pstate_ut_check_perf(u32 index)
>  static int amd_pstate_ut_check_freq(u32 index)
>  {
>  	int cpu = 0;
> -	struct amd_cpudata *cpudata = NULL;
>  
>  	for_each_possible_cpu(cpu) {
>  		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
> +		struct amd_cpudata *cpudata;
>  
>  		policy = cpufreq_cpu_get(cpu);
>  		if (!policy)
> -- 
> 2.43.0
> 

-- 
Thanks and Regards
gautham.

[PATCH v2 11/17] cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

Bitfield masks are easier to follow and less error prone.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Add a comment in msr-index.h
 * Pick up tag
---
 arch/x86/include/asm/msr-index.h | 20 +++++++++++---------
 arch/x86/kernel/acpi/cppc.c      |  2 +-
 drivers/cpufreq/amd-pstate-ut.c  |  8 ++++----
 drivers/cpufreq/amd-pstate.c     | 16 ++++++----------
 4 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 3eadc4d5de837..4bb87884998a0 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -700,15 +700,17 @@
 #define MSR_AMD_CPPC_REQ		0xc00102b3
 #define MSR_AMD_CPPC_STATUS		0xc00102b4
 
-#define AMD_CPPC_LOWEST_PERF(x)		(((x) >> 0) & 0xff)
-#define AMD_CPPC_LOWNONLIN_PERF(x)	(((x) >> 8) & 0xff)
-#define AMD_CPPC_NOMINAL_PERF(x)	(((x) >> 16) & 0xff)
-#define AMD_CPPC_HIGHEST_PERF(x)	(((x) >> 24) & 0xff)
-
-#define AMD_CPPC_MAX_PERF(x)		(((x) & 0xff) << 0)
-#define AMD_CPPC_MIN_PERF(x)		(((x) & 0xff) << 8)
-#define AMD_CPPC_DES_PERF(x)		(((x) & 0xff) << 16)
-#define AMD_CPPC_ENERGY_PERF_PREF(x)	(((x) & 0xff) << 24)
+/* Masks for use with MSR_AMD_CPPC_CAP1 */
+#define AMD_CPPC_LOWEST_PERF_MASK	GENMASK(7, 0)
+#define AMD_CPPC_LOWNONLIN_PERF_MASK	GENMASK(15, 8)
+#define AMD_CPPC_NOMINAL_PERF_MASK	GENMASK(23, 16)
+#define AMD_CPPC_HIGHEST_PERF_MASK	GENMASK(31, 24)
+
+/* Masks for use with MSR_AMD_CPPC_REQ */
+#define AMD_CPPC_MAX_PERF_MASK		GENMASK(7, 0)
+#define AMD_CPPC_MIN_PERF_MASK		GENMASK(15, 8)
+#define AMD_CPPC_DES_PERF_MASK		GENMASK(23, 16)
+#define AMD_CPPC_EPP_PERF_MASK		GENMASK(31, 24)
 
 /* AMD Performance Counter Global Status and Control MSRs */
 #define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS	0xc0000300
diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index f96053c305c61..77bfb846490c0 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -151,7 +151,7 @@ int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
 		if (ret)
 			goto out;
 
-		val = AMD_CPPC_HIGHEST_PERF(val);
+		val = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, val);
 	} else {
 		ret = cppc_get_highest_perf(cpu, &val);
 		if (ret)
diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index 9db20ac357042..067e9e325102e 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -142,10 +142,10 @@ static int amd_pstate_ut_check_perf(u32 index)
 				return ret;
 			}
 
-			highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
-			nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
-			lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
-			lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
+			highest_perf = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1);
+			nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
+			lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
+			lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
 		}
 
 		cur_perf = READ_ONCE(cpudata->perf);
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index e5983e5c77ba2..0a7e69fd32dbf 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -89,11 +89,6 @@ static bool cppc_enabled;
 static bool amd_pstate_prefcore = true;
 static struct quirk_entry *quirks;
 
-#define AMD_CPPC_MAX_PERF_MASK		GENMASK(7, 0)
-#define AMD_CPPC_MIN_PERF_MASK		GENMASK(15, 8)
-#define AMD_CPPC_DES_PERF_MASK		GENMASK(23, 16)
-#define AMD_CPPC_EPP_PERF_MASK		GENMASK(31, 24)
-
 /*
  * AMD Energy Preference Performance (EPP)
  * The EPP is used in the CCLK DPM controller to drive
@@ -439,12 +434,13 @@ static int msr_init_perf(struct amd_cpudata *cpudata)
 
 	perf.highest_perf = numerator;
 	perf.max_limit_perf = numerator;
-	perf.min_limit_perf = AMD_CPPC_LOWEST_PERF(cap1);
-	perf.nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
-	perf.lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
-	perf.lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
+	perf.min_limit_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
+	perf.nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
+	perf.lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
+	perf.lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
 	WRITE_ONCE(cpudata->perf, perf);
-	WRITE_ONCE(cpudata->prefcore_ranking, AMD_CPPC_HIGHEST_PERF(cap1));
+	WRITE_ONCE(cpudata->prefcore_ranking, FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1));
+
 	return 0;
 }
 
-- 
2.43.0

Re: [PATCH v2 11/17] cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:38PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> Bitfield masks are easier to follow and less error prone.


LGTM.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>




> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2:
>  * Add a comment in msr-index.h
>  * Pick up tag
> ---
>  arch/x86/include/asm/msr-index.h | 20 +++++++++++---------
>  arch/x86/kernel/acpi/cppc.c      |  2 +-
>  drivers/cpufreq/amd-pstate-ut.c  |  8 ++++----
>  drivers/cpufreq/amd-pstate.c     | 16 ++++++----------
>  4 files changed, 22 insertions(+), 24 deletions(-)
> 
> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
> index 3eadc4d5de837..4bb87884998a0 100644
> --- a/arch/x86/include/asm/msr-index.h
> +++ b/arch/x86/include/asm/msr-index.h
> @@ -700,15 +700,17 @@
>  #define MSR_AMD_CPPC_REQ		0xc00102b3
>  #define MSR_AMD_CPPC_STATUS		0xc00102b4
>  
> -#define AMD_CPPC_LOWEST_PERF(x)		(((x) >> 0) & 0xff)
> -#define AMD_CPPC_LOWNONLIN_PERF(x)	(((x) >> 8) & 0xff)
> -#define AMD_CPPC_NOMINAL_PERF(x)	(((x) >> 16) & 0xff)
> -#define AMD_CPPC_HIGHEST_PERF(x)	(((x) >> 24) & 0xff)
> -
> -#define AMD_CPPC_MAX_PERF(x)		(((x) & 0xff) << 0)
> -#define AMD_CPPC_MIN_PERF(x)		(((x) & 0xff) << 8)
> -#define AMD_CPPC_DES_PERF(x)		(((x) & 0xff) << 16)
> -#define AMD_CPPC_ENERGY_PERF_PREF(x)	(((x) & 0xff) << 24)
> +/* Masks for use with MSR_AMD_CPPC_CAP1 */
> +#define AMD_CPPC_LOWEST_PERF_MASK	GENMASK(7, 0)
> +#define AMD_CPPC_LOWNONLIN_PERF_MASK	GENMASK(15, 8)
> +#define AMD_CPPC_NOMINAL_PERF_MASK	GENMASK(23, 16)
> +#define AMD_CPPC_HIGHEST_PERF_MASK	GENMASK(31, 24)
> +
> +/* Masks for use with MSR_AMD_CPPC_REQ */
> +#define AMD_CPPC_MAX_PERF_MASK		GENMASK(7, 0)
> +#define AMD_CPPC_MIN_PERF_MASK		GENMASK(15, 8)
> +#define AMD_CPPC_DES_PERF_MASK		GENMASK(23, 16)
> +#define AMD_CPPC_EPP_PERF_MASK		GENMASK(31, 24)
>  
>  /* AMD Performance Counter Global Status and Control MSRs */
>  #define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS	0xc0000300
> diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
> index f96053c305c61..77bfb846490c0 100644
> --- a/arch/x86/kernel/acpi/cppc.c
> +++ b/arch/x86/kernel/acpi/cppc.c
> @@ -151,7 +151,7 @@ int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
>  		if (ret)
>  			goto out;
>  
> -		val = AMD_CPPC_HIGHEST_PERF(val);
> +		val = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, val);
>  	} else {
>  		ret = cppc_get_highest_perf(cpu, &val);
>  		if (ret)
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index 9db20ac357042..067e9e325102e 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -142,10 +142,10 @@ static int amd_pstate_ut_check_perf(u32 index)
>  				return ret;
>  			}
>  
> -			highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
> -			nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
> -			lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
> -			lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
> +			highest_perf = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1);
> +			nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
> +			lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
> +			lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
>  		}
>  
>  		cur_perf = READ_ONCE(cpudata->perf);
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index e5983e5c77ba2..0a7e69fd32dbf 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -89,11 +89,6 @@ static bool cppc_enabled;
>  static bool amd_pstate_prefcore = true;
>  static struct quirk_entry *quirks;
>  
> -#define AMD_CPPC_MAX_PERF_MASK		GENMASK(7, 0)
> -#define AMD_CPPC_MIN_PERF_MASK		GENMASK(15, 8)
> -#define AMD_CPPC_DES_PERF_MASK		GENMASK(23, 16)
> -#define AMD_CPPC_EPP_PERF_MASK		GENMASK(31, 24)
> -
>  /*
>   * AMD Energy Preference Performance (EPP)
>   * The EPP is used in the CCLK DPM controller to drive
> @@ -439,12 +434,13 @@ static int msr_init_perf(struct amd_cpudata *cpudata)
>  
>  	perf.highest_perf = numerator;
>  	perf.max_limit_perf = numerator;
> -	perf.min_limit_perf = AMD_CPPC_LOWEST_PERF(cap1);
> -	perf.nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
> -	perf.lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
> -	perf.lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
> +	perf.min_limit_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
> +	perf.nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
> +	perf.lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
> +	perf.lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
>  	WRITE_ONCE(cpudata->perf, perf);
> -	WRITE_ONCE(cpudata->prefcore_ranking, AMD_CPPC_HIGHEST_PERF(cap1));
> +	WRITE_ONCE(cpudata->prefcore_ranking, FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1));
> +
>  	return 0;
>  }
>  
> -- 
> 2.43.0
> 

-- 
Thanks and Regards
gautham.

Re: [PATCH v2 11/17] cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks

[kernel test robot]

Hi Mario,

kernel test robot noticed the following build errors:

[auto build test ERROR on amd-pstate/linux-next]
[also build test ERROR on amd-pstate/bleeding-edge]
[cannot apply to rafael-pm/linux-next rafael-pm/bleeding-edge tip/x86/core linus/master v6.14-rc3 next-20250217]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Mario-Limonciello/cpufreq-amd-pstate-Show-a-warning-when-a-CPU-fails-to-setup/20250215-085903
base:   https://git.kernel.org/pub/scm/linux/kernel/git/superm1/linux.git linux-next
patch link:    https://lore.kernel.org/r/20250215005244.1212285-12-superm1%40kernel.org
patch subject: [PATCH v2 11/17] cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks
config: i386-randconfig-063-20250216 (https://download.01.org/0day-ci/archive/20250218/202502180139.g2a2yoPe-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250218/202502180139.g2a2yoPe-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502180139.g2a2yoPe-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/cpufreq/amd-pstate-ut.c:145:19: error: call to undeclared function 'FIELD_GET'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     145 |                         highest_perf = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1);
         |                                        ^
   1 error generated.


vim +/FIELD_GET +145 drivers/cpufreq/amd-pstate-ut.c

   105	
   106	/*
   107	 * check if performance values are reasonable.
   108	 * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0
   109	 */
   110	static int amd_pstate_ut_check_perf(u32 index)
   111	{
   112		int cpu = 0, ret = 0;
   113		u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
   114		u64 cap1 = 0;
   115		struct cppc_perf_caps cppc_perf;
   116		struct amd_cpudata *cpudata = NULL;
   117		union perf_cached cur_perf;
   118	
   119		for_each_possible_cpu(cpu) {
   120			struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
   121	
   122			policy = cpufreq_cpu_get(cpu);
   123			if (!policy)
   124				continue;
   125			cpudata = policy->driver_data;
   126	
   127			if (get_shared_mem()) {
   128				ret = cppc_get_perf_caps(cpu, &cppc_perf);
   129				if (ret) {
   130					pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
   131					return ret;
   132				}
   133	
   134				highest_perf = cppc_perf.highest_perf;
   135				nominal_perf = cppc_perf.nominal_perf;
   136				lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
   137				lowest_perf = cppc_perf.lowest_perf;
   138			} else {
   139				ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
   140				if (ret) {
   141					pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
   142					return ret;
   143				}
   144	
 > 145				highest_perf = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1);
   146				nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
   147				lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
   148				lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
   149			}
   150	
   151			cur_perf = READ_ONCE(cpudata->perf);
   152			if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
   153				pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
   154					__func__, cpu, highest_perf, cpudata->perf.highest_perf);
   155				return -EINVAL;
   156			}
   157			if (nominal_perf != cur_perf.nominal_perf ||
   158			   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
   159			   (lowest_perf != cur_perf.lowest_perf)) {
   160				pr_err("%s cpu%d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
   161					__func__, cpu, nominal_perf, cpudata->perf.nominal_perf,
   162					lowest_nonlinear_perf, cpudata->perf.lowest_nonlinear_perf,
   163					lowest_perf, cpudata->perf.lowest_perf);
   164				return -EINVAL;
   165			}
   166	
   167			if (!((highest_perf >= nominal_perf) &&
   168				(nominal_perf > lowest_nonlinear_perf) &&
   169				(lowest_nonlinear_perf >= lowest_perf) &&
   170				(lowest_perf > 0))) {
   171				pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
   172					__func__, cpu, highest_perf, nominal_perf,
   173					lowest_nonlinear_perf, lowest_perf);
   174				return -EINVAL;
   175			}
   176		}
   177	
   178		return 0;
   179	}
   180	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v2 12/17] cpufreq/amd-pstate: Cache CPPC request in shared mem case too

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

In order to prevent a potential write for shmem_update_perf()
cache the request into the cppc_req_cached variable normally only
used for the MSR case.

This adds symmetry into the code and potentially avoids extra writes.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 0a7e69fd32dbf..9517da9b7e692 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -496,6 +496,8 @@ static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
 			     u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
 {
 	struct cppc_perf_ctrls perf_ctrls;
+	u64 value, prev;
+	int ret;
 
 	if (cppc_state == AMD_PSTATE_ACTIVE) {
 		int ret = shmem_set_epp(cpudata, epp);
@@ -504,11 +506,29 @@ static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
 			return ret;
 	}
 
+	value = prev = READ_ONCE(cpudata->cppc_req_cached);
+
+	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
+		   AMD_CPPC_DES_PERF_MASK | AMD_CPPC_EPP_PERF_MASK);
+	value |= FIELD_PREP(AMD_CPPC_MAX_PERF_MASK, max_perf);
+	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, des_perf);
+	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
+	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
+
+	if (value == prev)
+		return 0;
+
 	perf_ctrls.max_perf = max_perf;
 	perf_ctrls.min_perf = min_perf;
 	perf_ctrls.desired_perf = des_perf;
 
-	return cppc_set_perf(cpudata->cpu, &perf_ctrls);
+	ret = cppc_set_perf(cpudata->cpu, &perf_ctrls);
+	if (ret)
+		return ret;
+
+	WRITE_ONCE(cpudata->cppc_req_cached, value);
+
+	return 0;
 }
 
 static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
-- 
2.43.0

Re: [PATCH v2 12/17] cpufreq/amd-pstate: Cache CPPC request in shared mem case too

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:39PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> In order to prevent a potential write for shmem_update_perf()
> cache the request into the cppc_req_cached variable normally only
> used for the MSR case.
> 
> This adds symmetry into the code and potentially avoids extra writes.
> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 22 +++++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 0a7e69fd32dbf..9517da9b7e692 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -496,6 +496,8 @@ static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
>  			     u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
>  {
>  	struct cppc_perf_ctrls perf_ctrls;
> +	u64 value, prev;
> +	int ret;
>  
>  	if (cppc_state == AMD_PSTATE_ACTIVE) {
>  		int ret = shmem_set_epp(cpudata, epp);
> @@ -504,11 +506,29 @@ static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
>  			return ret;
>  	}
>  
> +	value = prev = READ_ONCE(cpudata->cppc_req_cached);
> +
> +	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
> +		   AMD_CPPC_DES_PERF_MASK | AMD_CPPC_EPP_PERF_MASK);
> +	value |= FIELD_PREP(AMD_CPPC_MAX_PERF_MASK, max_perf);
> +	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, des_perf);
> +	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
> +	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);


Perhaps this can be further simplified in the future using a new macro
FIELD_SET(var, mask, val) where

#define FIELD_SET(var, mask, val)     var = ((var) & ~(mask)) | FIELD_PREP(mask, val))

For this patch,

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>

-- 
Thanks and Regards
gautham.

[PATCH v2 13/17] cpufreq/amd-pstate: Move all EPP tracing into *_update_perf and *_set_epp functions

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

The EPP tracing is done by the caller today, but this precludes the
information about whether the CPPC request has changed.

Move it into the update_perf and set_epp functions and include information
about whether the request has changed from the last one.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate-trace.h |  13 +++-
 drivers/cpufreq/amd-pstate.c       | 119 +++++++++++++++++------------
 2 files changed, 81 insertions(+), 51 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-trace.h b/drivers/cpufreq/amd-pstate-trace.h
index f457d4af2c62e..32e1bdc588c52 100644
--- a/drivers/cpufreq/amd-pstate-trace.h
+++ b/drivers/cpufreq/amd-pstate-trace.h
@@ -90,7 +90,8 @@ TRACE_EVENT(amd_pstate_epp_perf,
 		 u8 epp,
 		 u8 min_perf,
 		 u8 max_perf,
-		 bool boost
+		 bool boost,
+		 bool changed
 		 ),
 
 	TP_ARGS(cpu_id,
@@ -98,7 +99,8 @@ TRACE_EVENT(amd_pstate_epp_perf,
 		epp,
 		min_perf,
 		max_perf,
-		boost),
+		boost,
+		changed),
 
 	TP_STRUCT__entry(
 		__field(unsigned int, cpu_id)
@@ -107,6 +109,7 @@ TRACE_EVENT(amd_pstate_epp_perf,
 		__field(u8, min_perf)
 		__field(u8, max_perf)
 		__field(bool, boost)
+		__field(bool, changed)
 		),
 
 	TP_fast_assign(
@@ -116,15 +119,17 @@ TRACE_EVENT(amd_pstate_epp_perf,
 		__entry->min_perf = min_perf;
 		__entry->max_perf = max_perf;
 		__entry->boost = boost;
+		__entry->changed = changed;
 		),
 
-	TP_printk("cpu%u: [%hhu<->%hhu]/%hhu, epp=%hhu, boost=%u",
+	TP_printk("cpu%u: [%hhu<->%hhu]/%hhu, epp=%hhu, boost=%u, changed=%u",
 		  (unsigned int)__entry->cpu_id,
 		  (u8)__entry->min_perf,
 		  (u8)__entry->max_perf,
 		  (u8)__entry->highest_perf,
 		  (u8)__entry->epp,
-		  (bool)__entry->boost
+		  (bool)__entry->boost,
+		  (bool)__entry->changed
 		 )
 );
 
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 9517da9b7e692..1304bdc23e809 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -228,9 +228,10 @@ static u8 shmem_get_epp(struct amd_cpudata *cpudata)
 	return FIELD_GET(AMD_CPPC_EPP_PERF_MASK, epp);
 }
 
-static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
+static int msr_update_perf(struct cpufreq_policy *policy, u8 min_perf,
 			   u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
 {
+	struct amd_cpudata *cpudata = policy->driver_data;
 	u64 value, prev;
 
 	value = prev = READ_ONCE(cpudata->cppc_req_cached);
@@ -242,6 +243,18 @@ static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
 	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
 	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
 
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		union perf_cached perf = READ_ONCE(cpudata->perf);
+
+		trace_amd_pstate_epp_perf(cpudata->cpu,
+					  perf.highest_perf,
+					  epp,
+					  min_perf,
+					  max_perf,
+					  policy->boost_enabled,
+					  value != prev);
+	}
+
 	if (value == prev)
 		return 0;
 
@@ -256,24 +269,26 @@ static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
 	}
 
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
-	WRITE_ONCE(cpudata->epp_cached, epp);
+	if (epp != cpudata->epp_cached)
+		WRITE_ONCE(cpudata->epp_cached, epp);
 
 	return 0;
 }
 
 DEFINE_STATIC_CALL(amd_pstate_update_perf, msr_update_perf);
 
-static inline int amd_pstate_update_perf(struct amd_cpudata *cpudata,
+static inline int amd_pstate_update_perf(struct cpufreq_policy *policy,
 					  u8 min_perf, u8 des_perf,
 					  u8 max_perf, u8 epp,
 					  bool fast_switch)
 {
-	return static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
+	return static_call(amd_pstate_update_perf)(policy, min_perf, des_perf,
 						   max_perf, epp, fast_switch);
 }
 
-static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
+static int msr_set_epp(struct cpufreq_policy *policy, u8 epp)
 {
+	struct amd_cpudata *cpudata = policy->driver_data;
 	u64 value, prev;
 	int ret;
 
@@ -281,6 +296,19 @@ static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
 	value &= ~AMD_CPPC_EPP_PERF_MASK;
 	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
 
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		union perf_cached perf = cpudata->perf;
+
+		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
+					  epp,
+					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
+						    cpudata->cppc_req_cached),
+					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK,
+						    cpudata->cppc_req_cached),
+					  policy->boost_enabled,
+					  value != prev);
+	}
+
 	if (value == prev)
 		return 0;
 
@@ -299,15 +327,29 @@ static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
 
 DEFINE_STATIC_CALL(amd_pstate_set_epp, msr_set_epp);
 
-static inline int amd_pstate_set_epp(struct amd_cpudata *cpudata, u8 epp)
+static inline int amd_pstate_set_epp(struct cpufreq_policy *policy, u8 epp)
 {
-	return static_call(amd_pstate_set_epp)(cpudata, epp);
+	return static_call(amd_pstate_set_epp)(policy, epp);
 }
 
-static int shmem_set_epp(struct amd_cpudata *cpudata, u8 epp)
+static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 {
-	int ret;
+	struct amd_cpudata *cpudata = policy->driver_data;
 	struct cppc_perf_ctrls perf_ctrls;
+	int ret;
+
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		union perf_cached perf = cpudata->perf;
+
+		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
+					  epp,
+					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
+						    cpudata->cppc_req_cached),
+					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK,
+						    cpudata->cppc_req_cached),
+					  policy->boost_enabled,
+					  epp != cpudata->epp_cached);
+	}
 
 	if (epp == cpudata->epp_cached)
 		return 0;
@@ -339,17 +381,7 @@ static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
 		return -EBUSY;
 	}
 
-	if (trace_amd_pstate_epp_perf_enabled()) {
-		union perf_cached perf = READ_ONCE(cpudata->perf);
-
-		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
-					  epp,
-					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
-					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
-					  policy->boost_enabled);
-	}
-
-	return amd_pstate_set_epp(cpudata, epp);
+	return amd_pstate_set_epp(policy, epp);
 }
 
 static inline int msr_cppc_enable(bool enable)
@@ -492,15 +524,16 @@ static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata)
 	return static_call(amd_pstate_init_perf)(cpudata);
 }
 
-static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
+static int shmem_update_perf(struct cpufreq_policy *policy, u8 min_perf,
 			     u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
 {
+	struct amd_cpudata *cpudata = policy->driver_data;
 	struct cppc_perf_ctrls perf_ctrls;
 	u64 value, prev;
 	int ret;
 
 	if (cppc_state == AMD_PSTATE_ACTIVE) {
-		int ret = shmem_set_epp(cpudata, epp);
+		int ret = shmem_set_epp(policy, epp);
 
 		if (ret)
 			return ret;
@@ -515,6 +548,18 @@ static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
 	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
 	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
 
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		union perf_cached perf = READ_ONCE(cpudata->perf);
+
+		trace_amd_pstate_epp_perf(cpudata->cpu,
+					  perf.highest_perf,
+					  epp,
+					  min_perf,
+					  max_perf,
+					  policy->boost_enabled,
+					  value != prev);
+	}
+
 	if (value == prev)
 		return 0;
 
@@ -592,7 +637,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
 				cpudata->cpu, fast_switch);
 	}
 
-	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
+	amd_pstate_update_perf(policy, min_perf, des_perf, max_perf, 0, fast_switch);
 }
 
 static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
@@ -1527,7 +1572,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 			return ret;
 		WRITE_ONCE(cpudata->cppc_req_cached, value);
 	}
-	ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
+	ret = amd_pstate_set_epp(policy, cpudata->epp_default);
 	if (ret)
 		return ret;
 
@@ -1568,14 +1613,8 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 		epp = READ_ONCE(cpudata->epp_cached);
 
 	perf = READ_ONCE(cpudata->perf);
-	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf, epp,
-					  perf.min_limit_perf,
-					  perf.max_limit_perf,
-					  policy->boost_enabled);
-	}
 
-	return amd_pstate_update_perf(cpudata, perf.min_limit_perf, 0U,
+	return amd_pstate_update_perf(policy, perf.min_limit_perf, 0U,
 				      perf.max_limit_perf, epp, false);
 }
 
@@ -1615,14 +1654,7 @@ static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
 	if (ret)
 		pr_err("failed to enable amd pstate during resume, return %d\n", ret);
 
-	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
-					  cpudata->epp_cached,
-					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
-					  perf.highest_perf, policy->boost_enabled);
-	}
-
-	return amd_pstate_update_perf(cpudata, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
+	return amd_pstate_update_perf(policy, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
 }
 
 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
@@ -1648,14 +1680,7 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 	if (cpudata->suspended)
 		return 0;
 
-	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
-					  AMD_CPPC_EPP_BALANCE_POWERSAVE,
-					  perf.lowest_perf, perf.lowest_perf,
-					  policy->boost_enabled);
-	}
-
-	return amd_pstate_update_perf(cpudata, perf.lowest_perf, 0, perf.lowest_perf,
+	return amd_pstate_update_perf(policy, perf.lowest_perf, 0, perf.lowest_perf,
 				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
 }
 
-- 
2.43.0

Re: [PATCH v2 13/17] cpufreq/amd-pstate: Move all EPP tracing into *_update_perf and *_set_epp functions

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:40PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> The EPP tracing is done by the caller today, but this precludes the
> information about whether the CPPC request has changed.
> 
> Move it into the update_perf and set_epp functions and include information
> about whether the request has changed from the last one.

A consequential change is that the amd_pstate_update_perf() and the
amd_pstate_set_epp() functions now have the cpufreq_policy parameter
in place of the cpudata parameter as policy->boost_enabled is needed
by the tracepoint. Can you please add this to the commit log?


Otherwise, the patch looks good to me.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>


-- 
Thanks and Regards
gautham.


> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/cpufreq/amd-pstate-trace.h |  13 +++-
>  drivers/cpufreq/amd-pstate.c       | 119 +++++++++++++++++------------
>  2 files changed, 81 insertions(+), 51 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-trace.h b/drivers/cpufreq/amd-pstate-trace.h
> index f457d4af2c62e..32e1bdc588c52 100644
> --- a/drivers/cpufreq/amd-pstate-trace.h
> +++ b/drivers/cpufreq/amd-pstate-trace.h
> @@ -90,7 +90,8 @@ TRACE_EVENT(amd_pstate_epp_perf,
>  		 u8 epp,
>  		 u8 min_perf,
>  		 u8 max_perf,
> -		 bool boost
> +		 bool boost,
> +		 bool changed
>  		 ),
>  
>  	TP_ARGS(cpu_id,
> @@ -98,7 +99,8 @@ TRACE_EVENT(amd_pstate_epp_perf,
>  		epp,
>  		min_perf,
>  		max_perf,
> -		boost),
> +		boost,
> +		changed),
>  
>  	TP_STRUCT__entry(
>  		__field(unsigned int, cpu_id)
> @@ -107,6 +109,7 @@ TRACE_EVENT(amd_pstate_epp_perf,
>  		__field(u8, min_perf)
>  		__field(u8, max_perf)
>  		__field(bool, boost)
> +		__field(bool, changed)
>  		),
>  
>  	TP_fast_assign(
> @@ -116,15 +119,17 @@ TRACE_EVENT(amd_pstate_epp_perf,
>  		__entry->min_perf = min_perf;
>  		__entry->max_perf = max_perf;
>  		__entry->boost = boost;
> +		__entry->changed = changed;
>  		),
>  
> -	TP_printk("cpu%u: [%hhu<->%hhu]/%hhu, epp=%hhu, boost=%u",
> +	TP_printk("cpu%u: [%hhu<->%hhu]/%hhu, epp=%hhu, boost=%u, changed=%u",
>  		  (unsigned int)__entry->cpu_id,
>  		  (u8)__entry->min_perf,
>  		  (u8)__entry->max_perf,
>  		  (u8)__entry->highest_perf,
>  		  (u8)__entry->epp,
> -		  (bool)__entry->boost
> +		  (bool)__entry->boost,
> +		  (bool)__entry->changed
>  		 )
>  );
>  
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 9517da9b7e692..1304bdc23e809 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -228,9 +228,10 @@ static u8 shmem_get_epp(struct amd_cpudata *cpudata)
>  	return FIELD_GET(AMD_CPPC_EPP_PERF_MASK, epp);
>  }
>  
> -static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
> +static int msr_update_perf(struct cpufreq_policy *policy, u8 min_perf,
>  			   u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
>  {
> +	struct amd_cpudata *cpudata = policy->driver_data;
>  	u64 value, prev;
>  
>  	value = prev = READ_ONCE(cpudata->cppc_req_cached);
> @@ -242,6 +243,18 @@ static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
>  	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
>  	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
>  
> +	if (trace_amd_pstate_epp_perf_enabled()) {
> +		union perf_cached perf = READ_ONCE(cpudata->perf);
> +
> +		trace_amd_pstate_epp_perf(cpudata->cpu,
> +					  perf.highest_perf,
> +					  epp,
> +					  min_perf,
> +					  max_perf,
> +					  policy->boost_enabled,
> +					  value != prev);
> +	}
> +
>  	if (value == prev)
>  		return 0;
>  
> @@ -256,24 +269,26 @@ static int msr_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
>  	}
>  
>  	WRITE_ONCE(cpudata->cppc_req_cached, value);
> -	WRITE_ONCE(cpudata->epp_cached, epp);
> +	if (epp != cpudata->epp_cached)
> +		WRITE_ONCE(cpudata->epp_cached, epp);
>  
>  	return 0;
>  }
>  
>  DEFINE_STATIC_CALL(amd_pstate_update_perf, msr_update_perf);
>  
> -static inline int amd_pstate_update_perf(struct amd_cpudata *cpudata,
> +static inline int amd_pstate_update_perf(struct cpufreq_policy *policy,
>  					  u8 min_perf, u8 des_perf,
>  					  u8 max_perf, u8 epp,
>  					  bool fast_switch)
>  {
> -	return static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
> +	return static_call(amd_pstate_update_perf)(policy, min_perf, des_perf,
>  						   max_perf, epp, fast_switch);
>  }
>  
> -static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
> +static int msr_set_epp(struct cpufreq_policy *policy, u8 epp)
>  {
> +	struct amd_cpudata *cpudata = policy->driver_data;
>  	u64 value, prev;
>  	int ret;
>  
> @@ -281,6 +296,19 @@ static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
>  	value &= ~AMD_CPPC_EPP_PERF_MASK;
>  	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
>  
> +	if (trace_amd_pstate_epp_perf_enabled()) {
> +		union perf_cached perf = cpudata->perf;
> +
> +		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> +					  epp,
> +					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
> +						    cpudata->cppc_req_cached),
> +					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK,
> +						    cpudata->cppc_req_cached),
> +					  policy->boost_enabled,
> +					  value != prev);
> +	}
> +
>  	if (value == prev)
>  		return 0;
>  
> @@ -299,15 +327,29 @@ static int msr_set_epp(struct amd_cpudata *cpudata, u8 epp)
>  
>  DEFINE_STATIC_CALL(amd_pstate_set_epp, msr_set_epp);
>  
> -static inline int amd_pstate_set_epp(struct amd_cpudata *cpudata, u8 epp)
> +static inline int amd_pstate_set_epp(struct cpufreq_policy *policy, u8 epp)
>  {
> -	return static_call(amd_pstate_set_epp)(cpudata, epp);
> +	return static_call(amd_pstate_set_epp)(policy, epp);
>  }
>  
> -static int shmem_set_epp(struct amd_cpudata *cpudata, u8 epp)
> +static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
>  {
> -	int ret;
> +	struct amd_cpudata *cpudata = policy->driver_data;
>  	struct cppc_perf_ctrls perf_ctrls;
> +	int ret;
> +
> +	if (trace_amd_pstate_epp_perf_enabled()) {
> +		union perf_cached perf = cpudata->perf;
> +
> +		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> +					  epp,
> +					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK,
> +						    cpudata->cppc_req_cached),
> +					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK,
> +						    cpudata->cppc_req_cached),
> +					  policy->boost_enabled,
> +					  epp != cpudata->epp_cached);
> +	}
>  
>  	if (epp == cpudata->epp_cached)
>  		return 0;
> @@ -339,17 +381,7 @@ static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
>  		return -EBUSY;
>  	}
>  
> -	if (trace_amd_pstate_epp_perf_enabled()) {
> -		union perf_cached perf = READ_ONCE(cpudata->perf);
> -
> -		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> -					  epp,
> -					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> -					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
> -					  policy->boost_enabled);
> -	}
> -
> -	return amd_pstate_set_epp(cpudata, epp);
> +	return amd_pstate_set_epp(policy, epp);
>  }
>  
>  static inline int msr_cppc_enable(bool enable)
> @@ -492,15 +524,16 @@ static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata)
>  	return static_call(amd_pstate_init_perf)(cpudata);
>  }
>  
> -static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
> +static int shmem_update_perf(struct cpufreq_policy *policy, u8 min_perf,
>  			     u8 des_perf, u8 max_perf, u8 epp, bool fast_switch)
>  {
> +	struct amd_cpudata *cpudata = policy->driver_data;
>  	struct cppc_perf_ctrls perf_ctrls;
>  	u64 value, prev;
>  	int ret;
>  
>  	if (cppc_state == AMD_PSTATE_ACTIVE) {
> -		int ret = shmem_set_epp(cpudata, epp);
> +		int ret = shmem_set_epp(policy, epp);
>  
>  		if (ret)
>  			return ret;
> @@ -515,6 +548,18 @@ static int shmem_update_perf(struct amd_cpudata *cpudata, u8 min_perf,
>  	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
>  	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
>  
> +	if (trace_amd_pstate_epp_perf_enabled()) {
> +		union perf_cached perf = READ_ONCE(cpudata->perf);
> +
> +		trace_amd_pstate_epp_perf(cpudata->cpu,
> +					  perf.highest_perf,
> +					  epp,
> +					  min_perf,
> +					  max_perf,
> +					  policy->boost_enabled,
> +					  value != prev);
> +	}
> +
>  	if (value == prev)
>  		return 0;
>  
> @@ -592,7 +637,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u8 min_perf,
>  				cpudata->cpu, fast_switch);
>  	}
>  
> -	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
> +	amd_pstate_update_perf(policy, min_perf, des_perf, max_perf, 0, fast_switch);
>  }
>  
>  static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
> @@ -1527,7 +1572,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  			return ret;
>  		WRITE_ONCE(cpudata->cppc_req_cached, value);
>  	}
> -	ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
> +	ret = amd_pstate_set_epp(policy, cpudata->epp_default);
>  	if (ret)
>  		return ret;
>  
> @@ -1568,14 +1613,8 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>  		epp = READ_ONCE(cpudata->epp_cached);
>  
>  	perf = READ_ONCE(cpudata->perf);
> -	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf, epp,
> -					  perf.min_limit_perf,
> -					  perf.max_limit_perf,
> -					  policy->boost_enabled);
> -	}
>  
> -	return amd_pstate_update_perf(cpudata, perf.min_limit_perf, 0U,
> +	return amd_pstate_update_perf(policy, perf.min_limit_perf, 0U,
>  				      perf.max_limit_perf, epp, false);
>  }
>  
> @@ -1615,14 +1654,7 @@ static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
>  	if (ret)
>  		pr_err("failed to enable amd pstate during resume, return %d\n", ret);
>  
> -	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> -					  cpudata->epp_cached,
> -					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> -					  perf.highest_perf, policy->boost_enabled);
> -	}
> -
> -	return amd_pstate_update_perf(cpudata, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
> +	return amd_pstate_update_perf(policy, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
>  }
>  
>  static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
> @@ -1648,14 +1680,7 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
>  	if (cpudata->suspended)
>  		return 0;
>  
> -	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
> -					  AMD_CPPC_EPP_BALANCE_POWERSAVE,
> -					  perf.lowest_perf, perf.lowest_perf,
> -					  policy->boost_enabled);
> -	}
> -
> -	return amd_pstate_update_perf(cpudata, perf.lowest_perf, 0, perf.lowest_perf,
> +	return amd_pstate_update_perf(policy, perf.lowest_perf, 0, perf.lowest_perf,
>  				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
>  }
>  
> -- 
> 2.43.0
> 

[PATCH v2 14/17] cpufreq/amd-pstate: Update cppc_req_cached for shared mem EPP writes

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

On EPP only writes update the cached variable so that the min/max
performance controls don't need to be updated again.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 1304bdc23e809..fd2b559f47c5c 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -336,6 +336,7 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 	struct cppc_perf_ctrls perf_ctrls;
+	u64 value;
 	int ret;
 
 	if (trace_amd_pstate_epp_perf_enabled()) {
@@ -362,6 +363,11 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 	}
 	WRITE_ONCE(cpudata->epp_cached, epp);
 
+	value = READ_ONCE(cpudata->cppc_req_cached);
+	value &= ~AMD_CPPC_EPP_PERF_MASK;
+	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
+	WRITE_ONCE(cpudata->cppc_req_cached, value);
+
 	return ret;
 }
 
-- 
2.43.0

Re: [PATCH v2 14/17] cpufreq/amd-pstate: Update cppc_req_cached for shared mem EPP writes

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:41PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> On EPP only writes update the cached variable so that the min/max
> performance controls don't need to be updated again.

This also paves the way to get rid of the cpudata->epp_cached variable
which you do in Patch 17.

LGTM

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>



> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 1304bdc23e809..fd2b559f47c5c 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -336,6 +336,7 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
>  {
>  	struct amd_cpudata *cpudata = policy->driver_data;
>  	struct cppc_perf_ctrls perf_ctrls;
> +	u64 value;
>  	int ret;
>  
>  	if (trace_amd_pstate_epp_perf_enabled()) {
> @@ -362,6 +363,11 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
>  	}
>  	WRITE_ONCE(cpudata->epp_cached, epp);
>  
> +	value = READ_ONCE(cpudata->cppc_req_cached);
> +	value &= ~AMD_CPPC_EPP_PERF_MASK;
> +	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
> +	WRITE_ONCE(cpudata->cppc_req_cached, value);
> +
>  	return ret;
>  }
>  
> -- 
> 2.43.0
> 

-- 
Thanks and Regards
gautham.

[PATCH v2 15/17] cpufreq/amd-pstate: Drop debug statements for policy setting

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

There are trace events that exist now for all amd-pstate modes that
will output information right before programming to the hardware.

This makes the existing debug statements unnecessary remaining
overhead.  Drop them.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index fd2b559f47c5c..b39bed12b360f 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -667,7 +667,6 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
 	}
 
 	cpufreq_verify_within_cpu_limits(policy_data);
-	pr_debug("policy_max =%d, policy_min=%d\n", policy_data->max, policy_data->min);
 
 	return 0;
 }
@@ -1632,9 +1631,6 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
 	if (!policy->cpuinfo.max_freq)
 		return -ENODEV;
 
-	pr_debug("set_policy: cpuinfo.max %u policy->max %u\n",
-				policy->cpuinfo.max_freq, policy->max);
-
 	cpudata->policy = policy->policy;
 
 	ret = amd_pstate_epp_update_limit(policy);
-- 
2.43.0

Re: [PATCH v2 15/17] cpufreq/amd-pstate: Drop debug statements for policy setting

[Gautham R. Shenoy]

On Fri, Feb 14, 2025 at 06:52:42PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> There are trace events that exist now for all amd-pstate modes that
> will output information right before programming to the hardware.
> 
> This makes the existing debug statements unnecessary remaining
> overhead.  Drop them.

Ack.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>


> 
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index fd2b559f47c5c..b39bed12b360f 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -667,7 +667,6 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
>  	}
>  
>  	cpufreq_verify_within_cpu_limits(policy_data);
> -	pr_debug("policy_max =%d, policy_min=%d\n", policy_data->max, policy_data->min);
>  
>  	return 0;
>  }
> @@ -1632,9 +1631,6 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>  	if (!policy->cpuinfo.max_freq)
>  		return -ENODEV;
>  
> -	pr_debug("set_policy: cpuinfo.max %u policy->max %u\n",
> -				policy->cpuinfo.max_freq, policy->max);
> -
>  	cpudata->policy = policy->policy;
>  
>  	ret = amd_pstate_epp_update_limit(policy);
> -- 
> 2.43.0
> 

-- 
Thanks and Regards
gautham.

[PATCH v2 16/17] cpufreq/amd-pstate: Rework CPPC enabling

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

The CPPC enable register is configured as "write once".  That is
any future writes don't actually do anything.

Because of this, all the cleanup paths that currently exist for
CPPC disable are non-effective.

Rework CPPC enable to only enable after all the CAP registers have
been read to avoid enabling CPPC on CPUs with invalid _CPC or
unpopulated MSRs.

As the register is write once, remove all cleanup paths as well.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 183 +++++++++++------------------------
 1 file changed, 57 insertions(+), 126 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index b39bed12b360f..1117dd4a6addd 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -85,7 +85,6 @@ static struct cpufreq_driver *current_pstate_driver;
 static struct cpufreq_driver amd_pstate_driver;
 static struct cpufreq_driver amd_pstate_epp_driver;
 static int cppc_state = AMD_PSTATE_UNDEFINED;
-static bool cppc_enabled;
 static bool amd_pstate_prefcore = true;
 static struct quirk_entry *quirks;
 
@@ -371,89 +370,40 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 	return ret;
 }
 
-static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
-					    int pref_index)
+static inline int msr_cppc_enable(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
-	u8 epp;
-
-	if (!pref_index)
-		epp = cpudata->epp_default;
-	else
-		epp = epp_values[pref_index];
-
-	if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) {
-		pr_debug("EPP cannot be set under performance policy\n");
-		return -EBUSY;
-	}
-
-	return amd_pstate_set_epp(policy, epp);
-}
-
-static inline int msr_cppc_enable(bool enable)
-{
-	int ret, cpu;
-	unsigned long logical_proc_id_mask = 0;
-
-       /*
-        * MSR_AMD_CPPC_ENABLE is write-once, once set it cannot be cleared.
-        */
-	if (!enable)
-		return 0;
-
-	if (enable == cppc_enabled)
-		return 0;
-
-	for_each_present_cpu(cpu) {
-		unsigned long logical_id = topology_logical_package_id(cpu);
-
-		if (test_bit(logical_id, &logical_proc_id_mask))
-			continue;
-
-		set_bit(logical_id, &logical_proc_id_mask);
-
-		ret = wrmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_ENABLE,
-				enable);
-		if (ret)
-			return ret;
-	}
 
-	cppc_enabled = enable;
-	return 0;
+	return wrmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_ENABLE, 1);
 }
 
-static int shmem_cppc_enable(bool enable)
+static int shmem_cppc_enable(struct cpufreq_policy *policy)
 {
-	int cpu, ret = 0;
+	struct amd_cpudata *cpudata = policy->driver_data;
 	struct cppc_perf_ctrls perf_ctrls;
+	int ret;
 
-	if (enable == cppc_enabled)
-		return 0;
+	ret = cppc_set_enable(cpudata->cpu, 1);
+	if (ret)
+		return ret;
 
-	for_each_present_cpu(cpu) {
-		ret = cppc_set_enable(cpu, enable);
+	/* Enable autonomous mode for EPP */
+	if (cppc_state == AMD_PSTATE_ACTIVE) {
+		/* Set desired perf as zero to allow EPP firmware control */
+		perf_ctrls.desired_perf = 0;
+		ret = cppc_set_perf(cpudata->cpu, &perf_ctrls);
 		if (ret)
 			return ret;
-
-		/* Enable autonomous mode for EPP */
-		if (cppc_state == AMD_PSTATE_ACTIVE) {
-			/* Set desired perf as zero to allow EPP firmware control */
-			perf_ctrls.desired_perf = 0;
-			ret = cppc_set_perf(cpu, &perf_ctrls);
-			if (ret)
-				return ret;
-		}
 	}
 
-	cppc_enabled = enable;
 	return ret;
 }
 
 DEFINE_STATIC_CALL(amd_pstate_cppc_enable, msr_cppc_enable);
 
-static inline int amd_pstate_cppc_enable(bool enable)
+static inline int amd_pstate_cppc_enable(struct cpufreq_policy *policy)
 {
-	return static_call(amd_pstate_cppc_enable)(enable);
+	return static_call(amd_pstate_cppc_enable)(policy);
 }
 
 static int msr_init_perf(struct amd_cpudata *cpudata)
@@ -1114,24 +1064,7 @@ static void amd_pstate_cpu_exit(struct cpufreq_policy *policy)
 
 static int amd_pstate_cpu_resume(struct cpufreq_policy *policy)
 {
-	int ret;
-
-	ret = amd_pstate_cppc_enable(true);
-	if (ret)
-		pr_err("failed to enable amd-pstate during resume, return %d\n", ret);
-
-	return ret;
-}
-
-static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
-{
-	int ret;
-
-	ret = amd_pstate_cppc_enable(false);
-	if (ret)
-		pr_err("failed to disable amd-pstate during suspend, return %d\n", ret);
-
-	return ret;
+	return amd_pstate_cppc_enable(policy);
 }
 
 /* Sysfs attributes */
@@ -1225,8 +1158,10 @@ static ssize_t show_energy_performance_available_preferences(
 static ssize_t store_energy_performance_preference(
 		struct cpufreq_policy *policy, const char *buf, size_t count)
 {
+	struct amd_cpudata *cpudata = policy->driver_data;
 	char str_preference[21];
 	ssize_t ret;
+	u8 epp;
 
 	ret = sscanf(buf, "%20s", str_preference);
 	if (ret != 1)
@@ -1236,7 +1171,29 @@ static ssize_t store_energy_performance_preference(
 	if (ret < 0)
 		return -EINVAL;
 
-	ret = amd_pstate_set_energy_pref_index(policy, ret);
+	if (!ret)
+		epp = cpudata->epp_default;
+	else
+		epp = epp_values[ret];
+
+	if (epp > 0 && policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
+		pr_debug("EPP cannot be set under performance policy\n");
+		return -EBUSY;
+	}
+
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		union perf_cached perf = cpudata->perf;
+
+		trace_amd_pstate_epp_perf(cpudata->cpu, perf.highest_perf,
+					  epp,
+					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
+					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
+					  policy->boost_enabled,
+					  FIELD_GET(AMD_CPPC_EPP_PERF_MASK,
+						    cpudata->cppc_req_cached) != epp);
+	}
+
+	ret = amd_pstate_set_epp(policy, epp);
 
 	return ret ? ret : count;
 }
@@ -1269,7 +1226,6 @@ static ssize_t show_energy_performance_preference(
 
 static void amd_pstate_driver_cleanup(void)
 {
-	amd_pstate_cppc_enable(false);
 	cppc_state = AMD_PSTATE_DISABLE;
 	current_pstate_driver = NULL;
 }
@@ -1303,14 +1259,6 @@ static int amd_pstate_register_driver(int mode)
 
 	cppc_state = mode;
 
-	ret = amd_pstate_cppc_enable(true);
-	if (ret) {
-		pr_err("failed to enable cppc during amd-pstate driver registration, return %d\n",
-		       ret);
-		amd_pstate_driver_cleanup();
-		return ret;
-	}
-
 	/* at least one CPU supports CPB */
 	current_pstate_driver->boost_enabled = cpu_feature_enabled(X86_FEATURE_CPB);
 
@@ -1550,11 +1498,15 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	policy->cpuinfo.max_freq = policy->max = perf_to_freq(perf,
 							      cpudata->nominal_freq,
 							      perf.highest_perf);
+	policy->driver_data = cpudata;
+
+	ret = amd_pstate_cppc_enable(policy);
+	if (ret)
+		goto free_cpudata1;
 
 	/* It will be updated by governor */
 	policy->cur = policy->cpuinfo.min_freq;
 
-	policy->driver_data = cpudata;
 
 	policy->boost_enabled = READ_ONCE(cpudata->boost_supported);
 
@@ -1646,32 +1598,27 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
 	return 0;
 }
 
-static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
+static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 	union perf_cached perf = READ_ONCE(cpudata->perf);
 	int ret;
 
-	ret = amd_pstate_cppc_enable(true);
-	if (ret)
-		pr_err("failed to enable amd pstate during resume, return %d\n", ret);
-
-	return amd_pstate_update_perf(policy, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
-}
+	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
 
-static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
-{
-	struct amd_cpudata *cpudata = policy->driver_data;
-	int ret;
+	ret = amd_pstate_cppc_enable(policy);
+	if (ret)
+		return ret;
 
-	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
 
-	ret = amd_pstate_epp_reenable(policy);
+	ret = amd_pstate_update_perf(policy, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
 	if (ret)
 		return ret;
+
 	cpudata->suspended = false;
 
 	return 0;
+
 }
 
 static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
@@ -1689,20 +1636,10 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
-	int ret;
-
-	/* avoid suspending when EPP is not enabled */
-	if (cppc_state != AMD_PSTATE_ACTIVE)
-		return 0;
 
 	/* set this flag to avoid setting core offline*/
 	cpudata->suspended = true;
 
-	/* disable CPPC in lowlevel firmware */
-	ret = amd_pstate_cppc_enable(false);
-	if (ret)
-		pr_err("failed to suspend, return %d\n", ret);
-
 	return 0;
 }
 
@@ -1710,12 +1647,8 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 
-	if (cpudata->suspended) {
-		/* enable amd pstate from suspend state*/
-		amd_pstate_epp_reenable(policy);
 
-		cpudata->suspended = false;
-	}
+	cpudata->suspended = false;
 
 	return 0;
 }
@@ -1727,7 +1660,6 @@ static struct cpufreq_driver amd_pstate_driver = {
 	.fast_switch    = amd_pstate_fast_switch,
 	.init		= amd_pstate_cpu_init,
 	.exit		= amd_pstate_cpu_exit,
-	.suspend	= amd_pstate_cpu_suspend,
 	.resume		= amd_pstate_cpu_resume,
 	.set_boost	= amd_pstate_set_boost,
 	.update_limits	= amd_pstate_update_limits,
@@ -1743,8 +1675,8 @@ static struct cpufreq_driver amd_pstate_epp_driver = {
 	.exit		= amd_pstate_epp_cpu_exit,
 	.offline	= amd_pstate_epp_cpu_offline,
 	.online		= amd_pstate_epp_cpu_online,
-	.suspend	= amd_pstate_epp_suspend,
-	.resume		= amd_pstate_epp_resume,
+	.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",
@@ -1895,7 +1827,6 @@ static int __init amd_pstate_init(void)
 
 global_attr_free:
 	cpufreq_unregister_driver(current_pstate_driver);
-	amd_pstate_cppc_enable(false);
 	return ret;
 }
 device_initcall(amd_pstate_init);
-- 
2.43.0

[PATCH v2 17/17] cpufreq/amd-pstate: Stop caching EPP

[Mario Limonciello]

From: Mario Limonciello <mario.limonciello@amd.com>

EPP values are cached in the cpudata structure per CPU. This is needless
though because they are also cached in the CPPC request variable.

Drop the separate cache for EPP values and always reference the CPPC
request variable when needed.

Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 27 ++++++++++++++-------------
 drivers/cpufreq/amd-pstate.h |  1 -
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 1117dd4a6addd..aafd765c43f30 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -268,8 +268,6 @@ static int msr_update_perf(struct cpufreq_policy *policy, u8 min_perf,
 	}
 
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
-	if (epp != cpudata->epp_cached)
-		WRITE_ONCE(cpudata->epp_cached, epp);
 
 	return 0;
 }
@@ -318,7 +316,6 @@ static int msr_set_epp(struct cpufreq_policy *policy, u8 epp)
 	}
 
 	/* update both so that msr_update_perf() can effectively check */
-	WRITE_ONCE(cpudata->epp_cached, epp);
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
 	return ret;
@@ -335,9 +332,12 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 	struct cppc_perf_ctrls perf_ctrls;
+	u8 epp_cached;
 	u64 value;
 	int ret;
 
+
+	epp_cached = FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cpudata->cppc_req_cached);
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		union perf_cached perf = cpudata->perf;
 
@@ -348,10 +348,10 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK,
 						    cpudata->cppc_req_cached),
 					  policy->boost_enabled,
-					  epp != cpudata->epp_cached);
+					  epp != epp_cached);
 	}
 
-	if (epp == cpudata->epp_cached)
+	if (epp == epp_cached)
 		return 0;
 
 	perf_ctrls.energy_perf = epp;
@@ -360,7 +360,6 @@ static int shmem_set_epp(struct cpufreq_policy *policy, u8 epp)
 		pr_debug("failed to set energy perf value (%d)\n", ret);
 		return ret;
 	}
-	WRITE_ONCE(cpudata->epp_cached, epp);
 
 	value = READ_ONCE(cpudata->cppc_req_cached);
 	value &= ~AMD_CPPC_EPP_PERF_MASK;
@@ -1202,9 +1201,11 @@ static ssize_t show_energy_performance_preference(
 				struct cpufreq_policy *policy, char *buf)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
-	u8 preference;
+	u8 preference, epp;
+
+	epp = FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cpudata->cppc_req_cached);
 
-	switch (cpudata->epp_cached) {
+	switch (epp) {
 	case AMD_CPPC_EPP_PERFORMANCE:
 		preference = EPP_INDEX_PERFORMANCE;
 		break;
@@ -1567,7 +1568,7 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
 		epp = 0;
 	else
-		epp = READ_ONCE(cpudata->epp_cached);
+		epp = FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cpudata->cppc_req_cached);
 
 	perf = READ_ONCE(cpudata->perf);
 
@@ -1603,22 +1604,22 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
 	struct amd_cpudata *cpudata = policy->driver_data;
 	union perf_cached perf = READ_ONCE(cpudata->perf);
 	int ret;
+	u8 epp;
+
+	epp = FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cpudata->cppc_req_cached);
 
 	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
 
 	ret = amd_pstate_cppc_enable(policy);
 	if (ret)
 		return ret;
-
-
-	ret = amd_pstate_update_perf(policy, 0, 0, perf.highest_perf, cpudata->epp_cached, false);
+	ret = amd_pstate_update_perf(policy, 0, 0, perf.highest_perf, epp, false);
 	if (ret)
 		return ret;
 
 	cpudata->suspended = false;
 
 	return 0;
-
 }
 
 static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
index 1a52582dbac9d..13918853f0a82 100644
--- a/drivers/cpufreq/amd-pstate.h
+++ b/drivers/cpufreq/amd-pstate.h
@@ -100,7 +100,6 @@ struct amd_cpudata {
 	bool	hw_prefcore;
 
 	/* EPP feature related attributes*/
-	u8	epp_cached;
 	u32	policy;
 	bool	suspended;
 	u8	epp_default;
-- 
2.43.0