[PATCH v2 00/16] amd-pstate fixes and improvements for 6.14

[PATCH v2 00/16] amd-pstate fixes and improvements for 6.14

[Mario Limonciello]

This series started as work on the behavior around boost numerator that
was changed in the last few kernels to make it more expected.

As part of the process of these improvements I found various other
optimizations that made a lot of sense in the context of the code.

While I was working on the issues I found it was really helpful to have
ftrace for EPP, so it introduces that as well.

Lastly a bug was reported requesting that amd-pstate default policy be
changed for client systems that don't use other software after bootup
so it includes that change too.

---
v2:
 * Pick up tags
 * Fix boost in some calls for tracing
 * Rename macro from AMD_PSTATE to AMD_CPPC
 * Use nominal freq for consistency
 * Drop unused lowest_perf variable
 * Drop extra mutex
 * Add patch to drop another unused variable

Mario Limonciello (16):
  cpufreq/amd-pstate: Store the boost numerator as highest perf again
  cpufreq/amd-pstate: Use boost numerator for upper bound of frequencies
  cpufreq/amd-pstate: Add trace event for EPP perf updates
  cpufreq/amd-pstate: convert mutex use to guard()
  cpufreq/amd-pstate: Drop cached epp_policy variable
  cpufreq/amd-pstate: Use FIELD_PREP and FIELD_GET macros
  cpufreq/amd-pstate: Only update the cached value in msr_set_epp() on
    success
  cpufreq/amd-pstate: store all values in cpudata struct in khz
  cpufreq/amd-pstate: Change amd_pstate_update_perf() to return an int
  cpufreq/amd-pstate: Move limit updating code
  cpufreq/amd-pstate: Cache EPP value and use that everywhere
  cpufreq/amd-pstate: Always write EPP value when updating perf
  cpufreq/amd-pstate: Check if CPPC request has changed before writing
    to the MSR or shared memory
  cpufreq/amd-pstate: Drop ret variable from
    amd_pstate_set_energy_pref_index()
  cpufreq/amd-pstate: Set different default EPP policy for Epyc and
    Ryzen
  cpufreq/amd-pstate: Drop boost_state variable

 Documentation/admin-guide/pm/amd-pstate.rst |   4 +-
 drivers/cpufreq/amd-pstate-trace.h          |  52 ++-
 drivers/cpufreq/amd-pstate-ut.c             |  12 +-
 drivers/cpufreq/amd-pstate.c                | 411 ++++++++++----------
 drivers/cpufreq/amd-pstate.h                |   3 -
 5 files changed, 250 insertions(+), 232 deletions(-)


base-commit: ab9e5b2eb56412cb8c63b46b935878d29205418e
-- 
2.43.0

[PATCH v2 01/16] cpufreq/amd-pstate: Store the boost numerator as highest perf again

[Mario Limonciello]

commit ad4caad58d91d ("cpufreq: amd-pstate: Merge
amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
changed the semantics for highest perf and commit 18d9b52271213
("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled")
worked around those semantic changes.

This however is a confusing result and furthermore makes it awkward to
change frequency limits and boost due to the scaling differences. Restore
the boost numerator to highest perf again.

Suggested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Fixes: ad4caad58d91 ("cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 Documentation/admin-guide/pm/amd-pstate.rst |  4 +---
 drivers/cpufreq/amd-pstate.c                | 25 ++++++++++++---------
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 210a808b74ec2..412423c54f258 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -251,9 +251,7 @@ performance supported in `AMD CPPC Performance Capability <perf_cap_>`_).
 In some ASICs, the highest CPPC performance is not the one in the ``_CPC``
 table, so we need to expose it to sysfs. If boost is not active, but
 still supported, this maximum frequency will be larger than the one in
-``cpuinfo``. On systems that support preferred core, the driver will have
-different values for some cores than others and this will reflect the values
-advertised by the platform at bootup.
+``cpuinfo``.
 This attribute is read-only.
 
 ``amd_pstate_lowest_nonlinear_freq``
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 66fb7aee95d24..c51026fe636a9 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -397,15 +397,19 @@ static inline int amd_pstate_cppc_enable(bool enable)
 
 static int msr_init_perf(struct amd_cpudata *cpudata)
 {
-	u64 cap1;
+	u64 cap1, numerator;
 
 	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
 				     &cap1);
 	if (ret)
 		return ret;
 
-	WRITE_ONCE(cpudata->highest_perf, AMD_CPPC_HIGHEST_PERF(cap1));
-	WRITE_ONCE(cpudata->max_limit_perf, AMD_CPPC_HIGHEST_PERF(cap1));
+	ret = amd_get_boost_ratio_numerator(cpudata->cpu, &numerator);
+	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));
@@ -417,13 +421,18 @@ static int msr_init_perf(struct amd_cpudata *cpudata)
 static int shmem_init_perf(struct amd_cpudata *cpudata)
 {
 	struct cppc_perf_caps cppc_perf;
+	u64 numerator;
 
 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
 	if (ret)
 		return ret;
 
-	WRITE_ONCE(cpudata->highest_perf, cppc_perf.highest_perf);
-	WRITE_ONCE(cpudata->max_limit_perf, cppc_perf.highest_perf);
+	ret = amd_get_boost_ratio_numerator(cpudata->cpu, &numerator);
+	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);
@@ -912,7 +921,6 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 {
 	int ret;
 	u32 min_freq, max_freq;
-	u64 numerator;
 	u32 nominal_perf, nominal_freq;
 	u32 lowest_nonlinear_perf, lowest_nonlinear_freq;
 	u32 boost_ratio, lowest_nonlinear_ratio;
@@ -934,10 +942,7 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 
-	ret = amd_get_boost_ratio_numerator(cpudata->cpu, &numerator);
-	if (ret)
-		return ret;
-	boost_ratio = div_u64(numerator << SCHED_CAPACITY_SHIFT, nominal_perf);
+	boost_ratio = div_u64(cpudata->highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);
 	max_freq = (nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT) * 1000;
 
 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
-- 
2.43.0

[PATCH v2 02/16] cpufreq/amd-pstate: Use boost numerator for upper bound of frequencies

[Mario Limonciello]

commit 18d9b5227121 ("cpufreq/amd-pstate: Use nominal perf for limits
when boost is disabled") introduced different semantics for min/max limits
based upon whether the user turned off boost from sysfs.

This however is not necessary when the highest perf value is the boost
numerator.

Suggested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Fixes: 18d9b5227121 ("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index c51026fe636a9..5e0edb65de32a 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -593,16 +593,13 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
 
 static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
 {
-	u32 max_limit_perf, min_limit_perf, lowest_perf, max_perf;
+	u32 max_limit_perf, min_limit_perf, lowest_perf, max_perf, max_freq;
 	struct amd_cpudata *cpudata = policy->driver_data;
 
-	if (cpudata->boost_supported && !policy->boost_enabled)
-		max_perf = READ_ONCE(cpudata->nominal_perf);
-	else
-		max_perf = READ_ONCE(cpudata->highest_perf);
-
-	max_limit_perf = div_u64(policy->max * max_perf, policy->cpuinfo.max_freq);
-	min_limit_perf = div_u64(policy->min * max_perf, policy->cpuinfo.max_freq);
+	max_perf = READ_ONCE(cpudata->highest_perf);
+	max_freq = READ_ONCE(cpudata->max_freq);
+	max_limit_perf = div_u64(policy->max * max_perf, max_freq);
+	min_limit_perf = div_u64(policy->min * max_perf, max_freq);
 
 	lowest_perf = READ_ONCE(cpudata->lowest_perf);
 	if (min_limit_perf < lowest_perf)
-- 
2.43.0

[PATCH v2 03/16] cpufreq/amd-pstate: Add trace event for EPP perf updates

[Mario Limonciello]

In "active" mode the most important thing for debugging whether
an issue is hardware or software based is to look at what was the
last thing written to the CPPC request MSR or shared memory region.

The 'amd_pstate_epp_perf' trace event shows the values being written
for all CPUs.

Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Fix boost in some calls
---
 drivers/cpufreq/amd-pstate-trace.h | 45 ++++++++++++++++++++++++++++++
 drivers/cpufreq/amd-pstate.c       | 28 +++++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/drivers/cpufreq/amd-pstate-trace.h b/drivers/cpufreq/amd-pstate-trace.h
index 35f38ae67fb13..e2221a4b6901c 100644
--- a/drivers/cpufreq/amd-pstate-trace.h
+++ b/drivers/cpufreq/amd-pstate-trace.h
@@ -88,6 +88,51 @@ TRACE_EVENT(amd_pstate_perf,
 		 )
 );
 
+TRACE_EVENT(amd_pstate_epp_perf,
+
+	TP_PROTO(unsigned int cpu_id,
+		 unsigned int highest_perf,
+		 unsigned int epp,
+		 unsigned int min_perf,
+		 unsigned int max_perf,
+		 bool boost
+		 ),
+
+	TP_ARGS(cpu_id,
+		highest_perf,
+		epp,
+		min_perf,
+		max_perf,
+		boost),
+
+	TP_STRUCT__entry(
+		__field(unsigned int, cpu_id)
+		__field(unsigned int, highest_perf)
+		__field(unsigned int, epp)
+		__field(unsigned int, min_perf)
+		__field(unsigned int, max_perf)
+		__field(bool, boost)
+		),
+
+	TP_fast_assign(
+		__entry->cpu_id = cpu_id;
+		__entry->highest_perf = highest_perf;
+		__entry->epp = epp;
+		__entry->min_perf = min_perf;
+		__entry->max_perf = max_perf;
+		__entry->boost = boost;
+		),
+
+	TP_printk("cpu%u: [%u<->%u]/%u, epp=%u, boost=%u",
+		  (unsigned int)__entry->cpu_id,
+		  (unsigned int)__entry->min_perf,
+		  (unsigned int)__entry->max_perf,
+		  (unsigned int)__entry->highest_perf,
+		  (unsigned int)__entry->epp,
+		  (bool)__entry->boost
+		 )
+);
+
 #endif /* _AMD_PSTATE_TRACE_H */
 
 /* This part must be outside protection */
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 5e0edb65de32a..a59c897dd59c7 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -324,6 +324,14 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
 		return -EBUSY;
 	}
 
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
+					  epp,
+					  AMD_CPPC_MIN_PERF(cpudata->cppc_req_cached),
+					  AMD_CPPC_MAX_PERF(cpudata->cppc_req_cached),
+					  cpudata->boost_state);
+	}
+
 	ret = amd_pstate_set_epp(cpudata, epp);
 
 	return ret;
@@ -1598,6 +1606,13 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
+	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,
+					  policy->boost_enabled);
+	}
+
 	amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
 			       cpudata->max_limit_perf, false);
 
@@ -1641,6 +1656,13 @@ static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
 
 	max_perf = READ_ONCE(cpudata->highest_perf);
 
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
+					  cpudata->epp_cached,
+					  AMD_CPPC_MIN_PERF(cpudata->cppc_req_cached),
+					  max_perf, cpudata->boost_state);
+	}
+
 	amd_pstate_update_perf(cpudata, 0, 0, max_perf, false);
 	amd_pstate_set_epp(cpudata, cpudata->epp_cached);
 }
@@ -1669,6 +1691,12 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 
 	mutex_lock(&amd_pstate_limits_lock);
 
+	if (trace_amd_pstate_epp_perf_enabled()) {
+		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
+					  AMD_CPPC_EPP_BALANCE_POWERSAVE,
+					  min_perf, min_perf, policy->boost_enabled);
+	}
+
 	amd_pstate_update_perf(cpudata, min_perf, 0, min_perf, false);
 	amd_pstate_set_epp(cpudata, AMD_CPPC_EPP_BALANCE_POWERSAVE);
 
-- 
2.43.0

[PATCH v2 04/16] cpufreq/amd-pstate: convert mutex use to guard()

[Mario Limonciello]

Using scoped guard declaration will unlock mutexes automatically.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index a59c897dd59c7..6a96d3a24c77e 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -758,12 +758,12 @@ 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;
 	}
-	mutex_lock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
+
 	ret = amd_pstate_cpu_boost_update(policy, state);
 	WRITE_ONCE(cpudata->boost_state, !ret ? state : false);
 	policy->boost_enabled = !ret ? state : false;
 	refresh_frequency_limits(policy);
-	mutex_unlock(&amd_pstate_driver_lock);
 
 	return ret;
 }
@@ -854,7 +854,8 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	if (!amd_pstate_prefcore)
 		return;
 
-	mutex_lock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
+
 	ret = amd_get_highest_perf(cpu, &cur_high);
 	if (ret)
 		goto free_cpufreq_put;
@@ -874,7 +875,6 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	if (!highest_perf_changed)
 		cpufreq_update_policy(cpu);
 
-	mutex_unlock(&amd_pstate_driver_lock);
 }
 
 /*
@@ -1203,11 +1203,11 @@ static ssize_t store_energy_performance_preference(
 	if (ret < 0)
 		return -EINVAL;
 
-	mutex_lock(&amd_pstate_limits_lock);
+	guard(mutex)(&amd_pstate_limits_lock);
+
 	ret = amd_pstate_set_energy_pref_index(cpudata, ret);
-	mutex_unlock(&amd_pstate_limits_lock);
 
-	return ret ?: count;
+	return ret ? ret : count;
 }
 
 static ssize_t show_energy_performance_preference(
@@ -1371,13 +1371,10 @@ EXPORT_SYMBOL_GPL(amd_pstate_update_status);
 static ssize_t status_show(struct device *dev,
 			   struct device_attribute *attr, char *buf)
 {
-	ssize_t ret;
 
-	mutex_lock(&amd_pstate_driver_lock);
-	ret = amd_pstate_show_status(buf);
-	mutex_unlock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
 
-	return ret;
+	return amd_pstate_show_status(buf);
 }
 
 static ssize_t status_store(struct device *a, struct device_attribute *b,
@@ -1386,9 +1383,8 @@ static ssize_t status_store(struct device *a, struct device_attribute *b,
 	char *p = memchr(buf, '\n', count);
 	int ret;
 
-	mutex_lock(&amd_pstate_driver_lock);
+	guard(mutex)(&amd_pstate_driver_lock);
 	ret = amd_pstate_update_status(buf, p ? p - buf : count);
-	mutex_unlock(&amd_pstate_driver_lock);
 
 	return ret < 0 ? ret : count;
 }
@@ -1689,7 +1685,7 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 
 	min_perf = READ_ONCE(cpudata->lowest_perf);
 
-	mutex_lock(&amd_pstate_limits_lock);
+	guard(mutex)(&amd_pstate_limits_lock);
 
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
@@ -1700,8 +1696,6 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 	amd_pstate_update_perf(cpudata, min_perf, 0, min_perf, false);
 	amd_pstate_set_epp(cpudata, AMD_CPPC_EPP_BALANCE_POWERSAVE);
 
-	mutex_unlock(&amd_pstate_limits_lock);
-
 	return 0;
 }
 
@@ -1730,13 +1724,11 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
 	struct amd_cpudata *cpudata = policy->driver_data;
 
 	if (cpudata->suspended) {
-		mutex_lock(&amd_pstate_limits_lock);
+		guard(mutex)(&amd_pstate_limits_lock);
 
 		/* enable amd pstate from suspend state*/
 		amd_pstate_epp_reenable(cpudata);
 
-		mutex_unlock(&amd_pstate_limits_lock);
-
 		cpudata->suspended = false;
 	}
 
-- 
2.43.0

[PATCH v2 05/16] cpufreq/amd-pstate: Drop cached epp_policy variable

[Mario Limonciello]

epp_policy is not used by any of the current code and there
is no need to cache it.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 3 ---
 drivers/cpufreq/amd-pstate.h | 2 --
 2 files changed, 5 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 6a96d3a24c77e..dd25e7e615984 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1478,7 +1478,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 		return -ENOMEM;
 
 	cpudata->cpu = policy->cpu;
-	cpudata->epp_policy = 0;
 
 	ret = amd_pstate_init_perf(cpudata);
 	if (ret)
@@ -1585,8 +1584,6 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	value &= ~AMD_CPPC_DES_PERF(~0L);
 	value |= AMD_CPPC_DES_PERF(0);
 
-	cpudata->epp_policy = cpudata->policy;
-
 	/* Get BIOS pre-defined epp value */
 	epp = amd_pstate_get_epp(cpudata, value);
 	if (epp < 0) {
diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
index cd573bc6b6db8..7765c82f975c6 100644
--- a/drivers/cpufreq/amd-pstate.h
+++ b/drivers/cpufreq/amd-pstate.h
@@ -57,7 +57,6 @@ struct amd_aperf_mperf {
  * @hw_prefcore: check whether HW supports preferred core featue.
  * 		  Only when hw_prefcore and early prefcore param are true,
  * 		  AMD P-State driver supports preferred core featue.
- * @epp_policy: Last saved policy used to set energy-performance preference
  * @epp_cached: Cached CPPC energy-performance preference value
  * @policy: Cpufreq policy value
  * @cppc_cap1_cached Cached MSR_AMD_CPPC_CAP1 register value
@@ -94,7 +93,6 @@ struct amd_cpudata {
 	bool	hw_prefcore;
 
 	/* EPP feature related attributes*/
-	s16	epp_policy;
 	s16	epp_cached;
 	u32	policy;
 	u64	cppc_cap1_cached;
-- 
2.43.0

[PATCH v2 06/16] cpufreq/amd-pstate: Use FIELD_PREP and FIELD_GET macros

[Mario Limonciello]

The FIELD_PREP and FIELD_GET macros improve readability and help
to avoid shifting bugs.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Add a missing case to traces
 * Use AMD_CPPC instead of AMD_PSTATE
---
 drivers/cpufreq/amd-pstate.c | 51 ++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 28 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index dd25e7e615984..0ed04316a8d80 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -22,6 +22,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/bitfield.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
@@ -88,6 +89,11 @@ 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
@@ -182,7 +188,6 @@ static DEFINE_MUTEX(amd_pstate_driver_lock);
 
 static s16 msr_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
 {
-	u64 epp;
 	int ret;
 
 	if (!cppc_req_cached) {
@@ -192,9 +197,8 @@ static s16 msr_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
 			return ret;
 		}
 	}
-	epp = (cppc_req_cached >> 24) & 0xFF;
 
-	return (s16)epp;
+	return FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cppc_req_cached);
 }
 
 DEFINE_STATIC_CALL(amd_pstate_get_epp, msr_get_epp);
@@ -269,12 +273,11 @@ static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata,
 
 static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
 {
-	int ret;
-
 	u64 value = READ_ONCE(cpudata->cppc_req_cached);
+	int ret;
 
-	value &= ~GENMASK_ULL(31, 24);
-	value |= (u64)epp << 24;
+	value &= ~AMD_CPPC_EPP_PERF_MASK;
+	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
 	ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
@@ -327,8 +330,8 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
 					  epp,
-					  AMD_CPPC_MIN_PERF(cpudata->cppc_req_cached),
-					  AMD_CPPC_MAX_PERF(cpudata->cppc_req_cached),
+					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
+					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
 					  cpudata->boost_state);
 	}
 
@@ -542,18 +545,15 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 		des_perf = 0;
 	}
 
-	value &= ~AMD_CPPC_MIN_PERF(~0L);
-	value |= AMD_CPPC_MIN_PERF(min_perf);
-
-	value &= ~AMD_CPPC_DES_PERF(~0L);
-	value |= AMD_CPPC_DES_PERF(des_perf);
-
 	/* limit the max perf when core performance boost feature is disabled */
 	if (!cpudata->boost_supported)
 		max_perf = min_t(unsigned long, nominal_perf, max_perf);
 
-	value &= ~AMD_CPPC_MAX_PERF(~0L);
-	value |= AMD_CPPC_MAX_PERF(max_perf);
+	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
+		   AMD_CPPC_DES_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);
 
 	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
 		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
@@ -1573,16 +1573,11 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
 		min_perf = min(cpudata->nominal_perf, max_perf);
 
-	/* Initial min/max values for CPPC Performance Controls Register */
-	value &= ~AMD_CPPC_MIN_PERF(~0L);
-	value |= AMD_CPPC_MIN_PERF(min_perf);
-
-	value &= ~AMD_CPPC_MAX_PERF(~0L);
-	value |= AMD_CPPC_MAX_PERF(max_perf);
-
-	/* CPPC EPP feature require to set zero to the desire perf bit */
-	value &= ~AMD_CPPC_DES_PERF(~0L);
-	value |= AMD_CPPC_DES_PERF(0);
+	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
+		   AMD_CPPC_DES_PERF_MASK);
+	value |= FIELD_PREP(AMD_CPPC_MAX_PERF_MASK, max_perf);
+	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, 0);
+	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
 
 	/* Get BIOS pre-defined epp value */
 	epp = amd_pstate_get_epp(cpudata, value);
@@ -1652,7 +1647,7 @@ static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
 	if (trace_amd_pstate_epp_perf_enabled()) {
 		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
 					  cpudata->epp_cached,
-					  AMD_CPPC_MIN_PERF(cpudata->cppc_req_cached),
+					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
 					  max_perf, cpudata->boost_state);
 	}
 
-- 
2.43.0

[PATCH v2 07/16] cpufreq/amd-pstate: Only update the cached value in msr_set_epp() on success

[Mario Limonciello]

If writing the MSR MSR_AMD_CPPC_REQ fails then the cached value in the
amd_cpudata structure should not be updated.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 0ed04316a8d80..263acce2f4b0c 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -278,11 +278,15 @@ static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
 
 	value &= ~AMD_CPPC_EPP_PERF_MASK;
 	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
-	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
 	ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
-	if (!ret)
-		cpudata->epp_cached = epp;
+	if (ret) {
+		pr_err("failed to set energy perf value (%d)\n", ret);
+		return ret;
+	}
+
+	cpudata->epp_cached = epp;
+	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
 	return ret;
 }
-- 
2.43.0

[PATCH v2 08/16] cpufreq/amd-pstate: store all values in cpudata struct in khz

[Mario Limonciello]

Storing values in the cpudata structure in different units leads
to confusion and hardcoded conversions elsewhere.  After ratios are
calculated store everything in khz for any future use. Adjust all
relevant consumers for this change as well.

Suggested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Adjust checks to use nominal_freq for consistency
---
 drivers/cpufreq/amd-pstate-ut.c | 12 +++++-------
 drivers/cpufreq/amd-pstate.c    | 28 ++++++++++++++--------------
 2 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
index a261d7300951e..3a0a380c3590c 100644
--- a/drivers/cpufreq/amd-pstate-ut.c
+++ b/drivers/cpufreq/amd-pstate-ut.c
@@ -207,7 +207,6 @@ static void amd_pstate_ut_check_freq(u32 index)
 	int cpu = 0;
 	struct cpufreq_policy *policy = NULL;
 	struct amd_cpudata *cpudata = NULL;
-	u32 nominal_freq_khz;
 
 	for_each_possible_cpu(cpu) {
 		policy = cpufreq_cpu_get(cpu);
@@ -215,14 +214,13 @@ static void amd_pstate_ut_check_freq(u32 index)
 			break;
 		cpudata = policy->driver_data;
 
-		nominal_freq_khz = cpudata->nominal_freq*1000;
-		if (!((cpudata->max_freq >= nominal_freq_khz) &&
-			(nominal_freq_khz > cpudata->lowest_nonlinear_freq) &&
+		if (!((cpudata->max_freq >= cpudata->nominal_freq) &&
+			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
 			(cpudata->lowest_nonlinear_freq > cpudata->min_freq) &&
 			(cpudata->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, nominal_freq_khz,
+				__func__, cpu, cpudata->max_freq, cpudata->nominal_freq,
 				cpudata->lowest_nonlinear_freq, cpudata->min_freq);
 			goto skip_test;
 		}
@@ -236,13 +234,13 @@ static void amd_pstate_ut_check_freq(u32 index)
 
 		if (cpudata->boost_supported) {
 			if ((policy->max == cpudata->max_freq) ||
-					(policy->max == nominal_freq_khz))
+					(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,
-					nominal_freq_khz);
+					cpudata->nominal_freq);
 				goto skip_test;
 			}
 		} else {
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 263acce2f4b0c..8a173359c2754 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -739,8 +739,8 @@ static int amd_pstate_cpu_boost_update(struct cpufreq_policy *policy, bool on)
 
 	if (on)
 		policy->cpuinfo.max_freq = max_freq;
-	else if (policy->cpuinfo.max_freq > nominal_freq * 1000)
-		policy->cpuinfo.max_freq = nominal_freq * 1000;
+	else if (policy->cpuinfo.max_freq > nominal_freq)
+		policy->cpuinfo.max_freq = nominal_freq;
 
 	policy->max = policy->cpuinfo.max_freq;
 
@@ -940,29 +940,29 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 		return ret;
 
 	if (quirks && quirks->lowest_freq)
-		min_freq = quirks->lowest_freq * 1000;
+		min_freq = quirks->lowest_freq;
 	else
-		min_freq = cppc_perf.lowest_freq * 1000;
+		min_freq = cppc_perf.lowest_freq;
 
 	if (quirks && quirks->nominal_freq)
-		nominal_freq = quirks->nominal_freq ;
+		nominal_freq = quirks->nominal_freq;
 	else
 		nominal_freq = cppc_perf.nominal_freq;
 
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 
 	boost_ratio = div_u64(cpudata->highest_perf << SCHED_CAPACITY_SHIFT, nominal_perf);
-	max_freq = (nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT) * 1000;
+	max_freq = (nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT);
 
 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
 	lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf << SCHED_CAPACITY_SHIFT,
 					 nominal_perf);
-	lowest_nonlinear_freq = (nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT) * 1000;
+	lowest_nonlinear_freq = (nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT);
 
-	WRITE_ONCE(cpudata->min_freq, min_freq);
-	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq);
-	WRITE_ONCE(cpudata->nominal_freq, nominal_freq);
-	WRITE_ONCE(cpudata->max_freq, max_freq);
+	WRITE_ONCE(cpudata->min_freq, min_freq * 1000);
+	WRITE_ONCE(cpudata->lowest_nonlinear_freq, lowest_nonlinear_freq * 1000);
+	WRITE_ONCE(cpudata->nominal_freq, nominal_freq * 1000);
+	WRITE_ONCE(cpudata->max_freq, max_freq * 1000);
 
 	/**
 	 * Below values need to be initialized correctly, otherwise driver will fail to load
@@ -972,13 +972,13 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 	 */
 	if (min_freq <= 0 || max_freq <= 0 || nominal_freq <= 0 || min_freq > max_freq) {
 		pr_err("min_freq(%d) or max_freq(%d) or nominal_freq(%d) value is incorrect\n",
-			min_freq, max_freq, nominal_freq * 1000);
+			min_freq, max_freq, nominal_freq);
 		return -EINVAL;
 	}
 
-	if (lowest_nonlinear_freq <= min_freq || lowest_nonlinear_freq > nominal_freq * 1000) {
+	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 * 1000);
+			lowest_nonlinear_freq, min_freq, nominal_freq);
 		return -EINVAL;
 	}
 
-- 
2.43.0

[PATCH v2 09/16] cpufreq/amd-pstate: Change amd_pstate_update_perf() to return an int

[Mario Limonciello]

As msr_update_perf() calls an MSR it's possible that it fails. Pass
this return code up to the caller.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 8a173359c2754..3a3df67c096d5 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -251,24 +251,26 @@ static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata)
 	return index;
 }
 
-static void msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
+static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
 			       u32 des_perf, u32 max_perf, bool fast_switch)
 {
-	if (fast_switch)
+	if (fast_switch) {
 		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
-	else
-		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
-			      READ_ONCE(cpudata->cppc_req_cached));
+		return 0;
+	}
+
+	return wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
+			     READ_ONCE(cpudata->cppc_req_cached));
 }
 
 DEFINE_STATIC_CALL(amd_pstate_update_perf, msr_update_perf);
 
-static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata,
+static inline int amd_pstate_update_perf(struct amd_cpudata *cpudata,
 					  u32 min_perf, u32 des_perf,
 					  u32 max_perf, bool fast_switch)
 {
-	static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
-					    max_perf, fast_switch);
+	return static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
+						   max_perf, fast_switch);
 }
 
 static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
@@ -480,7 +482,7 @@ static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata)
 	return static_call(amd_pstate_init_perf)(cpudata);
 }
 
-static void shmem_update_perf(struct amd_cpudata *cpudata,
+static int shmem_update_perf(struct amd_cpudata *cpudata,
 			     u32 min_perf, u32 des_perf,
 			     u32 max_perf, bool fast_switch)
 {
@@ -490,7 +492,7 @@ static void shmem_update_perf(struct amd_cpudata *cpudata,
 	perf_ctrls.min_perf = min_perf;
 	perf_ctrls.desired_perf = des_perf;
 
-	cppc_set_perf(cpudata->cpu, &perf_ctrls);
+	return cppc_set_perf(cpudata->cpu, &perf_ctrls);
 }
 
 static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
-- 
2.43.0

[PATCH v2 10/16] cpufreq/amd-pstate: Move limit updating code

[Mario Limonciello]

The limit updating code in amd_pstate_epp_update_limit() should not
only apply to EPP updates.  Move it to amd_pstate_update_min_max_limit()
so other callers can benefit as well.

With this move it's not necessary to have clamp_t calls anymore because
the verify callback is called when setting limits.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Drop lowest_perf variable
---
 drivers/cpufreq/amd-pstate.c | 28 +++++-----------------------
 1 file changed, 5 insertions(+), 23 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 3a3df67c096d5..dc3c45b6f5103 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -537,10 +537,6 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 	u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	u64 value = prev;
 
-	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
-			cpudata->max_limit_perf);
-	max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf,
-			cpudata->max_limit_perf);
 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
 
 	max_freq = READ_ONCE(cpudata->max_limit_freq);
@@ -607,7 +603,7 @@ static int amd_pstate_verify(struct cpufreq_policy_data *policy_data)
 
 static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
 {
-	u32 max_limit_perf, min_limit_perf, lowest_perf, max_perf, max_freq;
+	u32 max_limit_perf, min_limit_perf, max_perf, max_freq;
 	struct amd_cpudata *cpudata = policy->driver_data;
 
 	max_perf = READ_ONCE(cpudata->highest_perf);
@@ -615,12 +611,8 @@ static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
 	max_limit_perf = div_u64(policy->max * max_perf, max_freq);
 	min_limit_perf = div_u64(policy->min * max_perf, max_freq);
 
-	lowest_perf = READ_ONCE(cpudata->lowest_perf);
-	if (min_limit_perf < lowest_perf)
-		min_limit_perf = lowest_perf;
-
-	if (max_limit_perf < min_limit_perf)
-		max_limit_perf = min_limit_perf;
+	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
+		min_limit_perf = min(cpudata->nominal_perf, max_limit_perf);
 
 	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
 	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
@@ -1562,28 +1554,18 @@ 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;
-	u32 max_perf, min_perf;
 	u64 value;
 	s16 epp;
 
-	max_perf = READ_ONCE(cpudata->highest_perf);
-	min_perf = READ_ONCE(cpudata->lowest_perf);
 	amd_pstate_update_min_max_limit(policy);
 
-	max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf,
-			cpudata->max_limit_perf);
-	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
-			cpudata->max_limit_perf);
 	value = READ_ONCE(cpudata->cppc_req_cached);
 
-	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
-		min_perf = min(cpudata->nominal_perf, max_perf);
-
 	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
 		   AMD_CPPC_DES_PERF_MASK);
-	value |= FIELD_PREP(AMD_CPPC_MAX_PERF_MASK, max_perf);
+	value |= FIELD_PREP(AMD_CPPC_MAX_PERF_MASK, cpudata->max_limit_perf);
 	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, 0);
-	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, min_perf);
+	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
 
 	/* Get BIOS pre-defined epp value */
 	epp = amd_pstate_get_epp(cpudata, value);
-- 
2.43.0

[PATCH v2 11/16] cpufreq/amd-pstate: Cache EPP value and use that everywhere

[Mario Limonciello]

Cache the value in cpudata->epp_cached, and use that for all callers.
As all callers use cached value merge amd_pstate_get_energy_pref_index()
into show_energy_performance_preference().

Check if the EPP value is changed before writing it to MSR or
shared memory region.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2:
 * Drop extra mutex
---
 drivers/cpufreq/amd-pstate.c | 105 ++++++++++++++---------------------
 1 file changed, 43 insertions(+), 62 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index dc3c45b6f5103..d21acd961edcd 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -186,29 +186,28 @@ static inline int get_mode_idx_from_str(const char *str, size_t size)
 static DEFINE_MUTEX(amd_pstate_limits_lock);
 static DEFINE_MUTEX(amd_pstate_driver_lock);
 
-static s16 msr_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
+static s16 msr_get_epp(struct amd_cpudata *cpudata)
 {
+	u64 value;
 	int ret;
 
-	if (!cppc_req_cached) {
-		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &cppc_req_cached);
-		if (ret < 0) {
-			pr_debug("Could not retrieve energy perf value (%d)\n", ret);
-			return ret;
-		}
+	ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
+	if (ret < 0) {
+		pr_debug("Could not retrieve energy perf value (%d)\n", ret);
+		return ret;
 	}
 
-	return FIELD_GET(AMD_CPPC_EPP_PERF_MASK, cppc_req_cached);
+	return FIELD_GET(AMD_CPPC_EPP_PERF_MASK, value);
 }
 
 DEFINE_STATIC_CALL(amd_pstate_get_epp, msr_get_epp);
 
-static inline s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
+static inline s16 amd_pstate_get_epp(struct amd_cpudata *cpudata)
 {
-	return static_call(amd_pstate_get_epp)(cpudata, cppc_req_cached);
+	return static_call(amd_pstate_get_epp)(cpudata);
 }
 
-static s16 shmem_get_epp(struct amd_cpudata *cpudata, u64 dummy)
+static s16 shmem_get_epp(struct amd_cpudata *cpudata)
 {
 	u64 epp;
 	int ret;
@@ -222,35 +221,6 @@ static s16 shmem_get_epp(struct amd_cpudata *cpudata, u64 dummy)
 	return (s16)(epp & 0xff);
 }
 
-static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata)
-{
-	s16 epp;
-	int index = -EINVAL;
-
-	epp = amd_pstate_get_epp(cpudata, 0);
-	if (epp < 0)
-		return epp;
-
-	switch (epp) {
-	case AMD_CPPC_EPP_PERFORMANCE:
-		index = EPP_INDEX_PERFORMANCE;
-		break;
-	case AMD_CPPC_EPP_BALANCE_PERFORMANCE:
-		index = EPP_INDEX_BALANCE_PERFORMANCE;
-		break;
-	case AMD_CPPC_EPP_BALANCE_POWERSAVE:
-		index = EPP_INDEX_BALANCE_POWERSAVE;
-		break;
-	case AMD_CPPC_EPP_POWERSAVE:
-		index = EPP_INDEX_POWERSAVE;
-		break;
-	default:
-		break;
-	}
-
-	return index;
-}
-
 static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
 			       u32 des_perf, u32 max_perf, bool fast_switch)
 {
@@ -275,19 +245,23 @@ static inline int amd_pstate_update_perf(struct amd_cpudata *cpudata,
 
 static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
 {
-	u64 value = READ_ONCE(cpudata->cppc_req_cached);
+	u64 value, prev;
 	int ret;
 
+	value = prev = READ_ONCE(cpudata->cppc_req_cached);
 	value &= ~AMD_CPPC_EPP_PERF_MASK;
 	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, epp);
 
+	if (value == prev)
+		return 0;
+
 	ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
 	if (ret) {
 		pr_err("failed to set energy perf value (%d)\n", ret);
 		return ret;
 	}
 
-	cpudata->epp_cached = epp;
+	WRITE_ONCE(cpudata->epp_cached, epp);
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
 	return ret;
@@ -305,13 +279,16 @@ static int shmem_set_epp(struct amd_cpudata *cpudata, u32 epp)
 	int ret;
 	struct cppc_perf_ctrls perf_ctrls;
 
+	if (epp == cpudata->epp_cached)
+		return 0;
+
 	perf_ctrls.energy_perf = epp;
 	ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1);
 	if (ret) {
 		pr_debug("failed to set energy perf value (%d)\n", ret);
 		return ret;
 	}
-	cpudata->epp_cached = epp;
+	WRITE_ONCE(cpudata->epp_cached, epp);
 
 	return ret;
 }
@@ -1214,9 +1191,22 @@ static ssize_t show_energy_performance_preference(
 	struct amd_cpudata *cpudata = policy->driver_data;
 	int preference;
 
-	preference = amd_pstate_get_energy_pref_index(cpudata);
-	if (preference < 0)
-		return preference;
+	switch (cpudata->epp_cached) {
+	case AMD_CPPC_EPP_PERFORMANCE:
+		preference = EPP_INDEX_PERFORMANCE;
+		break;
+	case AMD_CPPC_EPP_BALANCE_PERFORMANCE:
+		preference = EPP_INDEX_BALANCE_PERFORMANCE;
+		break;
+	case AMD_CPPC_EPP_BALANCE_POWERSAVE:
+		preference = EPP_INDEX_BALANCE_POWERSAVE;
+		break;
+	case AMD_CPPC_EPP_POWERSAVE:
+		preference = EPP_INDEX_POWERSAVE;
+		break;
+	default:
+		return -EINVAL;
+	}
 
 	return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]);
 }
@@ -1501,7 +1491,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 
 	policy->driver_data = cpudata;
 
-	cpudata->epp_cached = cpudata->epp_default = amd_pstate_get_epp(cpudata, 0);
+	cpudata->epp_cached = cpudata->epp_default = amd_pstate_get_epp(cpudata);
 
 	policy->min = policy->cpuinfo.min_freq;
 	policy->max = policy->cpuinfo.max_freq;
@@ -1555,35 +1545,26 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 	u64 value;
-	s16 epp;
 
 	amd_pstate_update_min_max_limit(policy);
 
 	value = READ_ONCE(cpudata->cppc_req_cached);
 
 	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
-		   AMD_CPPC_DES_PERF_MASK);
+		   AMD_CPPC_DES_PERF_MASK | AMD_CPPC_EPP_PERF_MASK);
 	value |= FIELD_PREP(AMD_CPPC_MAX_PERF_MASK, cpudata->max_limit_perf);
 	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, 0);
 	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
 
-	/* Get BIOS pre-defined epp value */
-	epp = amd_pstate_get_epp(cpudata, value);
-	if (epp < 0) {
-		/**
-		 * This return value can only be negative for shared_memory
-		 * systems where EPP register read/write not supported.
-		 */
-		return epp;
-	}
-
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
-		epp = 0;
+		WRITE_ONCE(cpudata->epp_cached, 0);
+	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, cpudata->epp_cached);
 
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
 	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf, epp,
+		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
+					  cpudata->epp_cached,
 					  cpudata->min_limit_perf,
 					  cpudata->max_limit_perf,
 					  policy->boost_enabled);
@@ -1592,7 +1573,7 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
 			       cpudata->max_limit_perf, false);
 
-	return amd_pstate_set_epp(cpudata, epp);
+	return amd_pstate_set_epp(cpudata, READ_ONCE(cpudata->epp_cached));
 }
 
 static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
-- 
2.43.0

[PATCH v2 12/16] cpufreq/amd-pstate: Always write EPP value when updating perf

[Mario Limonciello]

For MSR systems the EPP value is in the same register as perf targets
and so divding them into two separate MSR writes is wasteful.

In msr_update_perf(), update both EPP and perf values in one write to
MSR_AMD_CPPC_REQ, and cache them if successful.

To accomplish this plumb the EPP value into the update_perf call and modify
all its callers to check the return value.

Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 71 ++++++++++++++++++++++--------------
 1 file changed, 43 insertions(+), 28 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index d21acd961edcd..dd11ba6c00cc3 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -222,25 +222,36 @@ static s16 shmem_get_epp(struct amd_cpudata *cpudata)
 }
 
 static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
-			       u32 des_perf, u32 max_perf, bool fast_switch)
+			   u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
 {
+	u64 value;
+
+	value = READ_ONCE(cpudata->cppc_req_cached);
 	if (fast_switch) {
 		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
 		return 0;
+	} else {
+		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
+					READ_ONCE(cpudata->cppc_req_cached));
+		if (ret)
+			return ret;
 	}
 
-	return wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
-			     READ_ONCE(cpudata->cppc_req_cached));
+	WRITE_ONCE(cpudata->cppc_req_cached, value);
+	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,
 					  u32 min_perf, u32 des_perf,
-					  u32 max_perf, bool fast_switch)
+					  u32 max_perf, u32 epp,
+					  bool fast_switch)
 {
 	return static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
-						   max_perf, fast_switch);
+						   max_perf, epp, fast_switch);
 }
 
 static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
@@ -459,12 +470,19 @@ 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,
-			     u32 min_perf, u32 des_perf,
-			     u32 max_perf, bool fast_switch)
+static int shmem_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
+			     u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
 {
 	struct cppc_perf_ctrls perf_ctrls;
 
+	if (cppc_state == AMD_PSTATE_ACTIVE) {
+		int ret = shmem_set_epp(cpudata, epp);
+
+		if (ret)
+			return ret;
+		WRITE_ONCE(cpudata->epp_cached, epp);
+	}
+
 	perf_ctrls.max_perf = max_perf;
 	perf_ctrls.min_perf = min_perf;
 	perf_ctrls.desired_perf = des_perf;
@@ -545,10 +563,10 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 
 	WRITE_ONCE(cpudata->cppc_req_cached, value);
 
-	amd_pstate_update_perf(cpudata, min_perf, des_perf,
-			       max_perf, fast_switch);
+	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
 
 cpufreq_policy_put:
+
 	cpufreq_cpu_put(policy);
 }
 
@@ -1545,6 +1563,7 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
 	u64 value;
+	u32 epp;
 
 	amd_pstate_update_min_max_limit(policy);
 
@@ -1557,23 +1576,19 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
 	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
 
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
-		WRITE_ONCE(cpudata->epp_cached, 0);
-	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, cpudata->epp_cached);
-
-	WRITE_ONCE(cpudata->cppc_req_cached, value);
+		epp = 0;
+	else
+		epp = READ_ONCE(cpudata->epp_cached);
 
 	if (trace_amd_pstate_epp_perf_enabled()) {
-		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
-					  cpudata->epp_cached,
+		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf, epp,
 					  cpudata->min_limit_perf,
 					  cpudata->max_limit_perf,
 					  policy->boost_enabled);
 	}
 
-	amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
-			       cpudata->max_limit_perf, false);
-
-	return amd_pstate_set_epp(cpudata, READ_ONCE(cpudata->epp_cached));
+	return amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
+				      cpudata->max_limit_perf, epp, false);
 }
 
 static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
@@ -1602,7 +1617,7 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
 	return 0;
 }
 
-static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
+static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
 {
 	u64 max_perf;
 	int ret;
@@ -1620,17 +1635,19 @@ static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
 					  max_perf, cpudata->boost_state);
 	}
 
-	amd_pstate_update_perf(cpudata, 0, 0, max_perf, false);
-	amd_pstate_set_epp(cpudata, cpudata->epp_cached);
+	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
 }
 
 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
 {
 	struct amd_cpudata *cpudata = policy->driver_data;
+	int ret;
 
 	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
 
-	amd_pstate_epp_reenable(cpudata);
+	ret = amd_pstate_epp_reenable(cpudata);
+	if (ret)
+		return ret;
 	cpudata->suspended = false;
 
 	return 0;
@@ -1654,10 +1671,8 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
 					  min_perf, min_perf, policy->boost_enabled);
 	}
 
-	amd_pstate_update_perf(cpudata, min_perf, 0, min_perf, false);
-	amd_pstate_set_epp(cpudata, AMD_CPPC_EPP_BALANCE_POWERSAVE);
-
-	return 0;
+	return amd_pstate_update_perf(cpudata, min_perf, 0, min_perf,
+				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
 }
 
 static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
-- 
2.43.0

Re: [PATCH v2 12/16] cpufreq/amd-pstate: Always write EPP value when updating perf

[Gautham R. Shenoy]

Hello Mario,

On Sun, Dec 08, 2024 at 12:30:27AM -0600, Mario Limonciello wrote:
> For MSR systems the EPP value is in the same register as perf targets
> and so divding them into two separate MSR writes is wasteful.
> 
> In msr_update_perf(), update both EPP and perf values in one write to
> MSR_AMD_CPPC_REQ, and cache them if successful.
> 
> To accomplish this plumb the EPP value into the update_perf call and modify
> all its callers to check the return value.
> 
> Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 71 ++++++++++++++++++++++--------------
>  1 file changed, 43 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index d21acd961edcd..dd11ba6c00cc3 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -222,25 +222,36 @@ static s16 shmem_get_epp(struct amd_cpudata *cpudata)
>  }
>  
>  static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
> -			       u32 des_perf, u32 max_perf, bool fast_switch)
> +			   u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>  {
> +	u64 value;
> +
> +	value = READ_ONCE(cpudata->cppc_req_cached);


There seems to be a mismatch here between what the API is passing and
parameters and how this function is *not* using them, and instead
using cpudata->cppc_req_cached.

The expectation seems to be that the max_perf, min_perf, des_perf and
epp fields in cpudata->cppc_req_cached would be the same as @des_perf,
@max_perf, @min_perf and @ep, no ?

Or is it that for the MSR update, the value in
cpudata->cppc_req_cached take precedence over the arguments passed ?

Ideally, the "value" should be recomputed here using (@min_perf |
@max_perf | @des_perf | @epp) and that value should be cached as you
are doing below.


>  	if (fast_switch) {
>  		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
>  		return 0;
> +	} else {
> +		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
> +					READ_ONCE(cpudata->cppc_req_cached));
> +		if (ret)
> +			return ret;
>  	}
>  
> -	return wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
> -			     READ_ONCE(cpudata->cppc_req_cached));
> +	WRITE_ONCE(cpudata->cppc_req_cached, value);

Since cppc_req_cached is not changed, why write it again ?

> +	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,
>  					  u32 min_perf, u32 des_perf,
> -					  u32 max_perf, bool fast_switch)
> +					  u32 max_perf, u32 epp,
> +					  bool fast_switch)
>  {
>  	return static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
> -						   max_perf, fast_switch);
> +						   max_perf, epp, fast_switch);
>  }
>  
>  static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
> @@ -459,12 +470,19 @@ 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,
> -			     u32 min_perf, u32 des_perf,
> -			     u32 max_perf, bool fast_switch)
> +static int shmem_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
> +			     u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>  {
>  	struct cppc_perf_ctrls perf_ctrls;
>  
> +	if (cppc_state == AMD_PSTATE_ACTIVE) {
> +		int ret = shmem_set_epp(cpudata, epp);
> +
> +		if (ret)
> +			return ret;
> +		WRITE_ONCE(cpudata->epp_cached, epp);
> +	}
> +
>  	perf_ctrls.max_perf = max_perf;
>  	perf_ctrls.min_perf = min_perf;
>  	perf_ctrls.desired_perf = des_perf;
> @@ -545,10 +563,10 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
>  
>  	WRITE_ONCE(cpudata->cppc_req_cached, value);
>  
> -	amd_pstate_update_perf(cpudata, min_perf, des_perf,
> -			       max_perf, fast_switch);
> +	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
>  
>  cpufreq_policy_put:
> +
>  	cpufreq_cpu_put(policy);
>  }
>  
> @@ -1545,6 +1563,7 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>  {
>  	struct amd_cpudata *cpudata = policy->driver_data;
>  	u64 value;
> +	u32 epp;
>  
>  	amd_pstate_update_min_max_limit(policy);
>  
> @@ -1557,23 +1576,19 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>  	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
>  
>  	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
> -		WRITE_ONCE(cpudata->epp_cached, 0);
> -	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, cpudata->epp_cached);
> -
> -	WRITE_ONCE(cpudata->cppc_req_cached, value);
> +		epp = 0;
> +	else
> +		epp = READ_ONCE(cpudata->epp_cached);
>  
>  	if (trace_amd_pstate_epp_perf_enabled()) {
> -		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
> -					  cpudata->epp_cached,
> +		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf, epp,
>  					  cpudata->min_limit_perf,
>  					  cpudata->max_limit_perf,
>  					  policy->boost_enabled);
>  	}
>  
> -	amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
> -			       cpudata->max_limit_perf, false);
> -
> -	return amd_pstate_set_epp(cpudata, READ_ONCE(cpudata->epp_cached));
> +	return amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
> +				      cpudata->max_limit_perf, epp, false);
>  }
>  
>  static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
> @@ -1602,7 +1617,7 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>  	return 0;
>  }
>  
> -static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
> +static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>  {
>  	u64 max_perf;
>  	int ret;
> @@ -1620,17 +1635,19 @@ static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>  					  max_perf, cpudata->boost_state);
>  	}
>  
> -	amd_pstate_update_perf(cpudata, 0, 0, max_perf, false);
> -	amd_pstate_set_epp(cpudata, cpudata->epp_cached);
> +	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
					       
On an MSR based system, none of the values passed here will be used,
and instead the value in cpudata->cppc_req_cached will be used, no?

>  }
>  
>  static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
>  {
>  	struct amd_cpudata *cpudata = policy->driver_data;
> +	int ret;
>  
>  	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
>  
> -	amd_pstate_epp_reenable(cpudata);
> +	ret = amd_pstate_epp_reenable(cpudata);
> +	if (ret)
> +		return ret;
>  	cpudata->suspended = false;
>  
>  	return 0;
> @@ -1654,10 +1671,8 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
>  					  min_perf, min_perf, policy->boost_enabled);
>  	}
>  
> -	amd_pstate_update_perf(cpudata, min_perf, 0, min_perf, false);
> -	amd_pstate_set_epp(cpudata, AMD_CPPC_EPP_BALANCE_POWERSAVE);
> -
> -	return 0;
> +	return amd_pstate_update_perf(cpudata, min_perf, 0, min_perf,
> +				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
>  }
>  
>  static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
> -- 
> 2.43.0
> 

--
Thanks and Regards
gautham.

Re: [PATCH v2 12/16] cpufreq/amd-pstate: Always write EPP value when updating perf

[Mario Limonciello]

On 12/9/2024 02:42, Gautham R. Shenoy wrote:
> Hello Mario,
> 
> On Sun, Dec 08, 2024 at 12:30:27AM -0600, Mario Limonciello wrote:
>> For MSR systems the EPP value is in the same register as perf targets
>> and so divding them into two separate MSR writes is wasteful.
>>
>> In msr_update_perf(), update both EPP and perf values in one write to
>> MSR_AMD_CPPC_REQ, and cache them if successful.
>>
>> To accomplish this plumb the EPP value into the update_perf call and modify
>> all its callers to check the return value.
>>
>> Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>>   drivers/cpufreq/amd-pstate.c | 71 ++++++++++++++++++++++--------------
>>   1 file changed, 43 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
>> index d21acd961edcd..dd11ba6c00cc3 100644
>> --- a/drivers/cpufreq/amd-pstate.c
>> +++ b/drivers/cpufreq/amd-pstate.c
>> @@ -222,25 +222,36 @@ static s16 shmem_get_epp(struct amd_cpudata *cpudata)
>>   }
>>   
>>   static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
>> -			       u32 des_perf, u32 max_perf, bool fast_switch)
>> +			   u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>>   {
>> +	u64 value;
>> +
>> +	value = READ_ONCE(cpudata->cppc_req_cached);
> 
> 
> There seems to be a mismatch here between what the API is passing and
> parameters and how this function is *not* using them, and instead
> using cpudata->cppc_req_cached.
> 
> The expectation seems to be that the max_perf, min_perf, des_perf and
> epp fields in cpudata->cppc_req_cached would be the same as @des_perf,
> @max_perf, @min_perf and @ep, no ?
> 
> Or is it that for the MSR update, the value in
> cpudata->cppc_req_cached take precedence over the arguments passed ?
> 
> Ideally, the "value" should be recomputed here using (@min_perf |
> @max_perf | @des_perf | @epp) and that value should be cached as you
> are doing below.
> 

Yeah - that's what the next patch does (which I think you probably saw 
after you reviewed it).

Do you think maybe I should just squash the two?  Or would you be 
happier if I re-ordered the two?

> 
>>   	if (fast_switch) {
>>   		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
>>   		return 0;
>> +	} else {
>> +		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
>> +					READ_ONCE(cpudata->cppc_req_cached));
>> +		if (ret)
>> +			return ret;
>>   	}
>>   
>> -	return wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
>> -			     READ_ONCE(cpudata->cppc_req_cached));
>> +	WRITE_ONCE(cpudata->cppc_req_cached, value);
> 
> Since cppc_req_cached is not changed, why write it again ?

Because of the next patch.  It will look at cpudata->cppc_req_cached and 
determine if anything changed in it - including EPP.


> 
>> +	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,
>>   					  u32 min_perf, u32 des_perf,
>> -					  u32 max_perf, bool fast_switch)
>> +					  u32 max_perf, u32 epp,
>> +					  bool fast_switch)
>>   {
>>   	return static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
>> -						   max_perf, fast_switch);
>> +						   max_perf, epp, fast_switch);
>>   }
>>   
>>   static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
>> @@ -459,12 +470,19 @@ 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,
>> -			     u32 min_perf, u32 des_perf,
>> -			     u32 max_perf, bool fast_switch)
>> +static int shmem_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
>> +			     u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>>   {
>>   	struct cppc_perf_ctrls perf_ctrls;
>>   
>> +	if (cppc_state == AMD_PSTATE_ACTIVE) {
>> +		int ret = shmem_set_epp(cpudata, epp);
>> +
>> +		if (ret)
>> +			return ret;
>> +		WRITE_ONCE(cpudata->epp_cached, epp);
>> +	}
>> +
>>   	perf_ctrls.max_perf = max_perf;
>>   	perf_ctrls.min_perf = min_perf;
>>   	perf_ctrls.desired_perf = des_perf;
>> @@ -545,10 +563,10 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
>>   
>>   	WRITE_ONCE(cpudata->cppc_req_cached, value);
>>   
>> -	amd_pstate_update_perf(cpudata, min_perf, des_perf,
>> -			       max_perf, fast_switch);
>> +	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
>>   
>>   cpufreq_policy_put:
>> +
>>   	cpufreq_cpu_put(policy);
>>   }
>>   
>> @@ -1545,6 +1563,7 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>>   {
>>   	struct amd_cpudata *cpudata = policy->driver_data;
>>   	u64 value;
>> +	u32 epp;
>>   
>>   	amd_pstate_update_min_max_limit(policy);
>>   
>> @@ -1557,23 +1576,19 @@ static int amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
>>   	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
>>   
>>   	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
>> -		WRITE_ONCE(cpudata->epp_cached, 0);
>> -	value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, cpudata->epp_cached);
>> -
>> -	WRITE_ONCE(cpudata->cppc_req_cached, value);
>> +		epp = 0;
>> +	else
>> +		epp = READ_ONCE(cpudata->epp_cached);
>>   
>>   	if (trace_amd_pstate_epp_perf_enabled()) {
>> -		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
>> -					  cpudata->epp_cached,
>> +		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf, epp,
>>   					  cpudata->min_limit_perf,
>>   					  cpudata->max_limit_perf,
>>   					  policy->boost_enabled);
>>   	}
>>   
>> -	amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
>> -			       cpudata->max_limit_perf, false);
>> -
>> -	return amd_pstate_set_epp(cpudata, READ_ONCE(cpudata->epp_cached));
>> +	return amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
>> +				      cpudata->max_limit_perf, epp, false);
>>   }
>>   
>>   static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>> @@ -1602,7 +1617,7 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>>   	return 0;
>>   }
>>   
>> -static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>> +static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>>   {
>>   	u64 max_perf;
>>   	int ret;
>> @@ -1620,17 +1635,19 @@ static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>>   					  max_perf, cpudata->boost_state);
>>   	}
>>   
>> -	amd_pstate_update_perf(cpudata, 0, 0, max_perf, false);
>> -	amd_pstate_set_epp(cpudata, cpudata->epp_cached);
>> +	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
>                                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 					
> On an MSR based system, none of the values passed here will be used,
> and instead the value in cpudata->cppc_req_cached will be used, no?

Currently; yes.  After the next patch that changes.

> 
>>   }
>>   
>>   static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
>>   {
>>   	struct amd_cpudata *cpudata = policy->driver_data;
>> +	int ret;
>>   
>>   	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
>>   
>> -	amd_pstate_epp_reenable(cpudata);
>> +	ret = amd_pstate_epp_reenable(cpudata);
>> +	if (ret)
>> +		return ret;
>>   	cpudata->suspended = false;
>>   
>>   	return 0;
>> @@ -1654,10 +1671,8 @@ static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
>>   					  min_perf, min_perf, policy->boost_enabled);
>>   	}
>>   
>> -	amd_pstate_update_perf(cpudata, min_perf, 0, min_perf, false);
>> -	amd_pstate_set_epp(cpudata, AMD_CPPC_EPP_BALANCE_POWERSAVE);
>> -
>> -	return 0;
>> +	return amd_pstate_update_perf(cpudata, min_perf, 0, min_perf,
>> +				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
>>   }
>>   
>>   static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
>> -- 
>> 2.43.0
>>
> 
> --
> Thanks and Regards
> gautham.

Re: [PATCH v2 12/16] cpufreq/amd-pstate: Always write EPP value when updating perf

[Mario Limonciello]

On 12/9/2024 10:49, Mario Limonciello wrote:
> On 12/9/2024 02:42, Gautham R. Shenoy wrote:
>> Hello Mario,
>>
>> On Sun, Dec 08, 2024 at 12:30:27AM -0600, Mario Limonciello wrote:
>>> For MSR systems the EPP value is in the same register as perf targets
>>> and so divding them into two separate MSR writes is wasteful.
>>>
>>> In msr_update_perf(), update both EPP and perf values in one write to
>>> MSR_AMD_CPPC_REQ, and cache them if successful.
>>>
>>> To accomplish this plumb the EPP value into the update_perf call and 
>>> modify
>>> all its callers to check the return value.
>>>
>>> Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
>>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>>> ---
>>>   drivers/cpufreq/amd-pstate.c | 71 ++++++++++++++++++++++--------------
>>>   1 file changed, 43 insertions(+), 28 deletions(-)
>>>
>>> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
>>> index d21acd961edcd..dd11ba6c00cc3 100644
>>> --- a/drivers/cpufreq/amd-pstate.c
>>> +++ b/drivers/cpufreq/amd-pstate.c
>>> @@ -222,25 +222,36 @@ static s16 shmem_get_epp(struct amd_cpudata 
>>> *cpudata)
>>>   }
>>>   static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
>>> -                   u32 des_perf, u32 max_perf, bool fast_switch)
>>> +               u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>>>   {
>>> +    u64 value;
>>> +
>>> +    value = READ_ONCE(cpudata->cppc_req_cached);
>>
>>
>> There seems to be a mismatch here between what the API is passing and
>> parameters and how this function is *not* using them, and instead
>> using cpudata->cppc_req_cached.
>>
>> The expectation seems to be that the max_perf, min_perf, des_perf and
>> epp fields in cpudata->cppc_req_cached would be the same as @des_perf,
>> @max_perf, @min_perf and @ep, no ?
>>
>> Or is it that for the MSR update, the value in
>> cpudata->cppc_req_cached take precedence over the arguments passed ?
>>
>> Ideally, the "value" should be recomputed here using (@min_perf |
>> @max_perf | @des_perf | @epp) and that value should be cached as you
>> are doing below.
>>
> 
> Yeah - that's what the next patch does (which I think you probably saw 
> after you reviewed it).
> 
> Do you think maybe I should just squash the two?  Or would you be 
> happier if I re-ordered the two?

FYI - I looked into re-ordering and it's not feasible because you need 
EPP plumbed in order to validate the result.

So I'm going to squash the two patches, and I'll do another one that 
adjusts tracing locations for your other feedback.

> 
>>
>>>       if (fast_switch) {
>>>           wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
>>>           return 0;
>>> +    } else {
>>> +        int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
>>> +                    READ_ONCE(cpudata->cppc_req_cached));
>>> +        if (ret)
>>> +            return ret;
>>>       }
>>> -    return wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
>>> -                 READ_ONCE(cpudata->cppc_req_cached));
>>> +    WRITE_ONCE(cpudata->cppc_req_cached, value);
>>
>> Since cppc_req_cached is not changed, why write it again ?
> 
> Because of the next patch.  It will look at cpudata->cppc_req_cached and 
> determine if anything changed in it - including EPP.
> 
> 
>>
>>> +    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,
>>>                         u32 min_perf, u32 des_perf,
>>> -                      u32 max_perf, bool fast_switch)
>>> +                      u32 max_perf, u32 epp,
>>> +                      bool fast_switch)
>>>   {
>>>       return static_call(amd_pstate_update_perf)(cpudata, min_perf, 
>>> des_perf,
>>> -                           max_perf, fast_switch);
>>> +                           max_perf, epp, fast_switch);
>>>   }
>>>   static int msr_set_epp(struct amd_cpudata *cpudata, u32 epp)
>>> @@ -459,12 +470,19 @@ 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,
>>> -                 u32 min_perf, u32 des_perf,
>>> -                 u32 max_perf, bool fast_switch)
>>> +static int shmem_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
>>> +                 u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>>>   {
>>>       struct cppc_perf_ctrls perf_ctrls;
>>> +    if (cppc_state == AMD_PSTATE_ACTIVE) {
>>> +        int ret = shmem_set_epp(cpudata, epp);
>>> +
>>> +        if (ret)
>>> +            return ret;
>>> +        WRITE_ONCE(cpudata->epp_cached, epp);
>>> +    }
>>> +
>>>       perf_ctrls.max_perf = max_perf;
>>>       perf_ctrls.min_perf = min_perf;
>>>       perf_ctrls.desired_perf = des_perf;
>>> @@ -545,10 +563,10 @@ static void amd_pstate_update(struct 
>>> amd_cpudata *cpudata, u32 min_perf,
>>>       WRITE_ONCE(cpudata->cppc_req_cached, value);
>>> -    amd_pstate_update_perf(cpudata, min_perf, des_perf,
>>> -                   max_perf, fast_switch);
>>> +    amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, 
>>> fast_switch);
>>>   cpufreq_policy_put:
>>> +
>>>       cpufreq_cpu_put(policy);
>>>   }
>>> @@ -1545,6 +1563,7 @@ static int amd_pstate_epp_update_limit(struct 
>>> cpufreq_policy *policy)
>>>   {
>>>       struct amd_cpudata *cpudata = policy->driver_data;
>>>       u64 value;
>>> +    u32 epp;
>>>       amd_pstate_update_min_max_limit(policy);
>>> @@ -1557,23 +1576,19 @@ static int amd_pstate_epp_update_limit(struct 
>>> cpufreq_policy *policy)
>>>       value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata- 
>>> >min_limit_perf);
>>>       if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
>>> -        WRITE_ONCE(cpudata->epp_cached, 0);
>>> -    value |= FIELD_PREP(AMD_CPPC_EPP_PERF_MASK, cpudata->epp_cached);
>>> -
>>> -    WRITE_ONCE(cpudata->cppc_req_cached, value);
>>> +        epp = 0;
>>> +    else
>>> +        epp = READ_ONCE(cpudata->epp_cached);
>>>       if (trace_amd_pstate_epp_perf_enabled()) {
>>> -        trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
>>> -                      cpudata->epp_cached,
>>> +        trace_amd_pstate_epp_perf(cpudata->cpu, cpudata- 
>>> >highest_perf, epp,
>>>                         cpudata->min_limit_perf,
>>>                         cpudata->max_limit_perf,
>>>                         policy->boost_enabled);
>>>       }
>>> -    amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
>>> -                   cpudata->max_limit_perf, false);
>>> -
>>> -    return amd_pstate_set_epp(cpudata, READ_ONCE(cpudata->epp_cached));
>>> +    return amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
>>> +                      cpudata->max_limit_perf, epp, false);
>>>   }
>>>   static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>>> @@ -1602,7 +1617,7 @@ static int amd_pstate_epp_set_policy(struct 
>>> cpufreq_policy *policy)
>>>       return 0;
>>>   }
>>> -static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>>> +static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>>>   {
>>>       u64 max_perf;
>>>       int ret;
>>> @@ -1620,17 +1635,19 @@ static void amd_pstate_epp_reenable(struct 
>>> amd_cpudata *cpudata)
>>>                         max_perf, cpudata->boost_state);
>>>       }
>>> -    amd_pstate_update_perf(cpudata, 0, 0, max_perf, false);
>>> -    amd_pstate_set_epp(cpudata, cpudata->epp_cached);
>>> +    return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata- 
>>> >epp_cached, false);
>>                                                 
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>
>> On an MSR based system, none of the values passed here will be used,
>> and instead the value in cpudata->cppc_req_cached will be used, no?
> 
> Currently; yes.  After the next patch that changes.
> 
>>
>>>   }
>>>   static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
>>>   {
>>>       struct amd_cpudata *cpudata = policy->driver_data;
>>> +    int ret;
>>>       pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
>>> -    amd_pstate_epp_reenable(cpudata);
>>> +    ret = amd_pstate_epp_reenable(cpudata);
>>> +    if (ret)
>>> +        return ret;
>>>       cpudata->suspended = false;
>>>       return 0;
>>> @@ -1654,10 +1671,8 @@ static int amd_pstate_epp_cpu_offline(struct 
>>> cpufreq_policy *policy)
>>>                         min_perf, min_perf, policy->boost_enabled);
>>>       }
>>> -    amd_pstate_update_perf(cpudata, min_perf, 0, min_perf, false);
>>> -    amd_pstate_set_epp(cpudata, AMD_CPPC_EPP_BALANCE_POWERSAVE);
>>> -
>>> -    return 0;
>>> +    return amd_pstate_update_perf(cpudata, min_perf, 0, min_perf,
>>> +                      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
>>>   }
>>>   static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
>>> -- 
>>> 2.43.0
>>>
>>
>> -- 
>> Thanks and Regards
>> gautham.
> 

Re: [PATCH v2 12/16] cpufreq/amd-pstate: Always write EPP value when updating perf

[Gautham R. Shenoy]

On Mon, Dec 09, 2024 at 11:15:49AM -0600, Mario Limonciello wrote:
> On 12/9/2024 10:49, Mario Limonciello wrote:
> > On 12/9/2024 02:42, Gautham R. Shenoy wrote:
> > > Hello Mario,
> > > 
> > > On Sun, Dec 08, 2024 at 12:30:27AM -0600, Mario Limonciello wrote:
> > > > For MSR systems the EPP value is in the same register as perf targets
> > > > and so divding them into two separate MSR writes is wasteful.
> > > > 
> > > > In msr_update_perf(), update both EPP and perf values in one write to
> > > > MSR_AMD_CPPC_REQ, and cache them if successful.
> > > > 
> > > > To accomplish this plumb the EPP value into the update_perf call
> > > > and modify
> > > > all its callers to check the return value.
> > > > 
> > > > Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> > > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> > > > ---
> > > >   drivers/cpufreq/amd-pstate.c | 71 ++++++++++++++++++++++--------------
> > > >   1 file changed, 43 insertions(+), 28 deletions(-)
> > > > 
> > > > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> > > > index d21acd961edcd..dd11ba6c00cc3 100644
> > > > --- a/drivers/cpufreq/amd-pstate.c
> > > > +++ b/drivers/cpufreq/amd-pstate.c
> > > > @@ -222,25 +222,36 @@ static s16 shmem_get_epp(struct
> > > > amd_cpudata *cpudata)
> > > >   }
> > > >   static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
> > > > -                   u32 des_perf, u32 max_perf, bool fast_switch)
> > > > +               u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
> > > >   {
> > > > +    u64 value;
> > > > +
> > > > +    value = READ_ONCE(cpudata->cppc_req_cached);
> > > 
> > > 
> > > There seems to be a mismatch here between what the API is passing and
> > > parameters and how this function is *not* using them, and instead
> > > using cpudata->cppc_req_cached.
> > > 
> > > The expectation seems to be that the max_perf, min_perf, des_perf and
> > > epp fields in cpudata->cppc_req_cached would be the same as @des_perf,
> > > @max_perf, @min_perf and @ep, no ?
> > > 
> > > Or is it that for the MSR update, the value in
> > > cpudata->cppc_req_cached take precedence over the arguments passed ?
> > > 
> > > Ideally, the "value" should be recomputed here using (@min_perf |
> > > @max_perf | @des_perf | @epp) and that value should be cached as you
> > > are doing below.
> > > 
> > 
> > Yeah - that's what the next patch does (which I think you probably saw
> > after you reviewed it).
> > 
> > Do you think maybe I should just squash the two?  Or would you be
> > happier if I re-ordered the two?
> 
> FYI - I looked into re-ordering and it's not feasible because you need EPP
> plumbed in order to validate the result.
> 
> So I'm going to squash the two patches, and I'll do another one that adjusts
> tracing locations for your other feedback.

Yeah, it is not possible to reorder the two. I like the newer version
better.


--
Thanks and Regards
gautham.

[PATCH v2 13/16] cpufreq/amd-pstate: Check if CPPC request has changed before writing to the MSR or shared memory

[Mario Limonciello]

Move the common MSR field formatting code to msr_update_perf() from
its callers.

Ensure that the MSR write is necessary before flushing a write out.
Also drop the comparison from the passive flow tracing.

Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate-trace.h |  7 +----
 drivers/cpufreq/amd-pstate.c       | 47 +++++++++++-------------------
 2 files changed, 18 insertions(+), 36 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate-trace.h b/drivers/cpufreq/amd-pstate-trace.h
index e2221a4b6901c..8d692415d9050 100644
--- a/drivers/cpufreq/amd-pstate-trace.h
+++ b/drivers/cpufreq/amd-pstate-trace.h
@@ -32,7 +32,6 @@ TRACE_EVENT(amd_pstate_perf,
 		 u64 aperf,
 		 u64 tsc,
 		 unsigned int cpu_id,
-		 bool changed,
 		 bool fast_switch
 		 ),
 
@@ -44,7 +43,6 @@ TRACE_EVENT(amd_pstate_perf,
 		aperf,
 		tsc,
 		cpu_id,
-		changed,
 		fast_switch
 		),
 
@@ -57,7 +55,6 @@ TRACE_EVENT(amd_pstate_perf,
 		__field(unsigned long long, aperf)
 		__field(unsigned long long, tsc)
 		__field(unsigned int, cpu_id)
-		__field(bool, changed)
 		__field(bool, fast_switch)
 		),
 
@@ -70,11 +67,10 @@ TRACE_EVENT(amd_pstate_perf,
 		__entry->aperf = aperf;
 		__entry->tsc = tsc;
 		__entry->cpu_id = cpu_id;
-		__entry->changed = changed;
 		__entry->fast_switch = fast_switch;
 		),
 
-	TP_printk("amd_min_perf=%lu amd_des_perf=%lu amd_max_perf=%lu freq=%llu mperf=%llu aperf=%llu tsc=%llu cpu_id=%u changed=%s fast_switch=%s",
+	TP_printk("amd_min_perf=%lu amd_des_perf=%lu amd_max_perf=%lu freq=%llu mperf=%llu aperf=%llu tsc=%llu cpu_id=%u fast_switch=%s",
 		  (unsigned long)__entry->min_perf,
 		  (unsigned long)__entry->target_perf,
 		  (unsigned long)__entry->capacity,
@@ -83,7 +79,6 @@ TRACE_EVENT(amd_pstate_perf,
 		  (unsigned long long)__entry->aperf,
 		  (unsigned long long)__entry->tsc,
 		  (unsigned int)__entry->cpu_id,
-		  (__entry->changed) ? "true" : "false",
 		  (__entry->fast_switch) ? "true" : "false"
 		 )
 );
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index dd11ba6c00cc3..2178931fbf87b 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -224,15 +224,26 @@ static s16 shmem_get_epp(struct amd_cpudata *cpudata)
 static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
 			   u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
 {
-	u64 value;
+	u64 value, prev;
+
+	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;
 
-	value = READ_ONCE(cpudata->cppc_req_cached);
 	if (fast_switch) {
-		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
+		wrmsrl(MSR_AMD_CPPC_REQ, value);
 		return 0;
 	} else {
-		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
-					READ_ONCE(cpudata->cppc_req_cached));
+		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
+
 		if (ret)
 			return ret;
 	}
@@ -528,9 +539,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 {
 	unsigned long max_freq;
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpudata->cpu);
-	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
 	u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
-	u64 value = prev;
 
 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
 
@@ -546,27 +555,14 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 	if (!cpudata->boost_supported)
 		max_perf = min_t(unsigned long, nominal_perf, max_perf);
 
-	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
-		   AMD_CPPC_DES_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);
-
 	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
 		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
 			cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc,
-				cpudata->cpu, (value != prev), fast_switch);
+				cpudata->cpu, fast_switch);
 	}
 
-	if (value == prev)
-		goto cpufreq_policy_put;
-
-	WRITE_ONCE(cpudata->cppc_req_cached, value);
-
 	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
 
-cpufreq_policy_put:
-
 	cpufreq_cpu_put(policy);
 }
 
@@ -1562,19 +1558,10 @@ 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;
-	u64 value;
 	u32 epp;
 
 	amd_pstate_update_min_max_limit(policy);
 
-	value = 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, cpudata->max_limit_perf);
-	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, 0);
-	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
-
 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
 		epp = 0;
 	else
-- 
2.43.0

Re: [PATCH v2 13/16] cpufreq/amd-pstate: Check if CPPC request has changed before writing to the MSR or shared memory

[Gautham R. Shenoy]

Hello Mario,


On Sun, Dec 08, 2024 at 12:30:28AM -0600, Mario Limonciello wrote:
> Move the common MSR field formatting code to msr_update_perf() from
> its callers.
> 
> Ensure that the MSR write is necessary before flushing a write out.
> Also drop the comparison from the passive flow tracing.
> 
> Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---

[..snip..]

> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index dd11ba6c00cc3..2178931fbf87b 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -224,15 +224,26 @@ static s16 shmem_get_epp(struct amd_cpudata *cpudata)
>  static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
>  			   u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>  {
> -	u64 value;
> +	u64 value, prev;
> +
> +	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;
>  
> -	value = READ_ONCE(cpudata->cppc_req_cached);
>  	if (fast_switch) {
> -		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
> +		wrmsrl(MSR_AMD_CPPC_REQ, value);
>  		return 0;
>  	} else {
> -		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
> -					READ_ONCE(cpudata->cppc_req_cached));
> +		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
> +
>  		if (ret)
>  			return ret;

Ok, so you are recomputing the value in this patch. Does it also make
sense to move trace_amd_pstate_perf() call to this place?


--
Thanks and Regards
gautham.

>  	}
> @@ -528,9 +539,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
>  {
>  	unsigned long max_freq;
>  	struct cpufreq_policy *policy = cpufreq_cpu_get(cpudata->cpu);
> -	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
>  	u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
> -	u64 value = prev;
>  
>  	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
>  
> @@ -546,27 +555,14 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
>  	if (!cpudata->boost_supported)
>  		max_perf = min_t(unsigned long, nominal_perf, max_perf);
>  
> -	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
> -		   AMD_CPPC_DES_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);
> -
>  	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
>  		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
>  			cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc,
> -				cpudata->cpu, (value != prev), fast_switch);
> +				cpudata->cpu, fast_switch);
>  	}
>  
> -	if (value == prev)
> -		goto cpufreq_policy_put;
> -
> -	WRITE_ONCE(cpudata->cppc_req_cached, value);
> -
>  	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
>  
> -cpufreq_policy_put:
> -
>  	cpufreq_cpu_put(policy);
>  }
>  
> @@ -1562,19 +1558,10 @@ 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;
> -	u64 value;
>  	u32 epp;
>  
>  	amd_pstate_update_min_max_limit(policy);
>  
> -	value = 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, cpudata->max_limit_perf);
> -	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, 0);
> -	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
> -
>  	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
>  		epp = 0;
>  	else
> -- 
> 2.43.0
> 

Re: [PATCH v2 13/16] cpufreq/amd-pstate: Check if CPPC request has changed before writing to the MSR or shared memory

[Mario Limonciello]

On 12/9/2024 02:56, Gautham R. Shenoy wrote:
> Hello Mario,
> 
> 
> On Sun, Dec 08, 2024 at 12:30:28AM -0600, Mario Limonciello wrote:
>> Move the common MSR field formatting code to msr_update_perf() from
>> its callers.
>>
>> Ensure that the MSR write is necessary before flushing a write out.
>> Also drop the comparison from the passive flow tracing.
>>
>> Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
> 
> [..snip..]
> 
>> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
>> index dd11ba6c00cc3..2178931fbf87b 100644
>> --- a/drivers/cpufreq/amd-pstate.c
>> +++ b/drivers/cpufreq/amd-pstate.c
>> @@ -224,15 +224,26 @@ static s16 shmem_get_epp(struct amd_cpudata *cpudata)
>>   static int msr_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
>>   			   u32 des_perf, u32 max_perf, u32 epp, bool fast_switch)
>>   {
>> -	u64 value;
>> +	u64 value, prev;
>> +
>> +	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;
>>   
>> -	value = READ_ONCE(cpudata->cppc_req_cached);
>>   	if (fast_switch) {
>> -		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
>> +		wrmsrl(MSR_AMD_CPPC_REQ, value);
>>   		return 0;
>>   	} else {
>> -		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
>> -					READ_ONCE(cpudata->cppc_req_cached));
>> +		int ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
>> +
>>   		if (ret)
>>   			return ret;
> 
> Ok, so you are recomputing the value in this patch. Does it also make
> sense to move trace_amd_pstate_perf() call to this place?

You mean so that essentially it only logs events that REALLY write to 
the MSR/shared memory region?

I guess with an ftrace function call graph + that event you can 
effectively determine that is what happened.

An alternative is to move it right above the (value == prev) check and 
include "prev" in the trace event.

I think that's my preference at least - you capture whether it changed 
and what the intent was.

> 
> 
> --
> Thanks and Regards
> gautham.
> 
>>   	}
>> @@ -528,9 +539,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
>>   {
>>   	unsigned long max_freq;
>>   	struct cpufreq_policy *policy = cpufreq_cpu_get(cpudata->cpu);
>> -	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
>>   	u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
>> -	u64 value = prev;
>>   
>>   	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
>>   
>> @@ -546,27 +555,14 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
>>   	if (!cpudata->boost_supported)
>>   		max_perf = min_t(unsigned long, nominal_perf, max_perf);
>>   
>> -	value &= ~(AMD_CPPC_MAX_PERF_MASK | AMD_CPPC_MIN_PERF_MASK |
>> -		   AMD_CPPC_DES_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);
>> -
>>   	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
>>   		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
>>   			cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc,
>> -				cpudata->cpu, (value != prev), fast_switch);
>> +				cpudata->cpu, fast_switch);
>>   	}
>>   
>> -	if (value == prev)
>> -		goto cpufreq_policy_put;
>> -
>> -	WRITE_ONCE(cpudata->cppc_req_cached, value);
>> -
>>   	amd_pstate_update_perf(cpudata, min_perf, des_perf, max_perf, 0, fast_switch);
>>   
>> -cpufreq_policy_put:
>> -
>>   	cpufreq_cpu_put(policy);
>>   }
>>   
>> @@ -1562,19 +1558,10 @@ 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;
>> -	u64 value;
>>   	u32 epp;
>>   
>>   	amd_pstate_update_min_max_limit(policy);
>>   
>> -	value = 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, cpudata->max_limit_perf);
>> -	value |= FIELD_PREP(AMD_CPPC_DES_PERF_MASK, 0);
>> -	value |= FIELD_PREP(AMD_CPPC_MIN_PERF_MASK, cpudata->min_limit_perf);
>> -
>>   	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
>>   		epp = 0;
>>   	else
>> -- 
>> 2.43.0
>>

[PATCH v2 14/16] cpufreq/amd-pstate: Drop ret variable from amd_pstate_set_energy_pref_index()

[Mario Limonciello]

The ret variable is not necessary.

Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 2178931fbf87b..5869bcd287e87 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -318,13 +318,11 @@ static int shmem_set_epp(struct amd_cpudata *cpudata, u32 epp)
 static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
 		int pref_index)
 {
-	int epp = -EINVAL;
-	int ret;
+	int epp;
 
 	if (!pref_index)
 		epp = cpudata->epp_default;
-
-	if (epp == -EINVAL)
+	else
 		epp = epp_values[pref_index];
 
 	if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) {
@@ -340,9 +338,7 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
 					  cpudata->boost_state);
 	}
 
-	ret = amd_pstate_set_epp(cpudata, epp);
-
-	return ret;
+	return amd_pstate_set_epp(cpudata, epp);
 }
 
 static inline int msr_cppc_enable(bool enable)
-- 
2.43.0

Re: [PATCH v2 14/16] cpufreq/amd-pstate: Drop ret variable from amd_pstate_set_energy_pref_index()

[Gautham R. Shenoy]

On Sun, Dec 08, 2024 at 12:30:29AM -0600, Mario Limonciello wrote:
> The ret variable is not necessary.
> 
> Reviewed-and-tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> 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 | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 2178931fbf87b..5869bcd287e87 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -318,13 +318,11 @@ static int shmem_set_epp(struct amd_cpudata *cpudata, u32 epp)
>  static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
>  		int pref_index)
>  {
> -	int epp = -EINVAL;
> -	int ret;
> +	int epp;
>  
>  	if (!pref_index)
>  		epp = cpudata->epp_default;
> -
> -	if (epp == -EINVAL)
> +	else
>  		epp = epp_values[pref_index];
>  
>  	if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) {
> @@ -340,9 +338,7 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
>  					  cpudata->boost_state);
>  	}
>  
> -	ret = amd_pstate_set_epp(cpudata, epp);
> -
> -	return ret;
> +	return amd_pstate_set_epp(cpudata, epp);
>  }
>  
>  static inline int msr_cppc_enable(bool enable)
> -- 
> 2.43.0
> 

[PATCH v2 15/16] cpufreq/amd-pstate: Set different default EPP policy for Epyc and Ryzen

[Mario Limonciello]

For Ryzen systems the EPP policy set by the BIOS is generally configured
to performance as this is the default register value for the CPPC request
MSR.

If a user doesn't use additional software to configure EPP then the system
will default biased towards performance and consume extra battery. Instead
configure the default to "balanced_performance" for this case.

Suggested-by: Artem S. Tashkinov <aros@gmx.com>
Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219526
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 5869bcd287e87..a4ededb8d89df 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -1501,8 +1501,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 
 	policy->driver_data = cpudata;
 
-	cpudata->epp_cached = cpudata->epp_default = amd_pstate_get_epp(cpudata);
-
 	policy->min = policy->cpuinfo.min_freq;
 	policy->max = policy->cpuinfo.max_freq;
 
@@ -1513,10 +1511,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	 * the default cpufreq governor is neither powersave nor performance.
 	 */
 	if (amd_pstate_acpi_pm_profile_server() ||
-	    amd_pstate_acpi_pm_profile_undefined())
+	    amd_pstate_acpi_pm_profile_undefined()) {
 		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
-	else
+		cpudata->epp_default = amd_pstate_get_epp(cpudata);
+	} else {
 		policy->policy = CPUFREQ_POLICY_POWERSAVE;
+		cpudata->epp_default = AMD_CPPC_EPP_BALANCE_PERFORMANCE;
+	}
 
 	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
 		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
@@ -1529,6 +1530,9 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 			return ret;
 		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
 	}
+	ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
+	if (ret)
+		return ret;
 
 	current_pstate_driver->adjust_perf = NULL;
 
-- 
2.43.0

Re: [PATCH v2 15/16] cpufreq/amd-pstate: Set different default EPP policy for Epyc and Ryzen

[Gautham R. Shenoy]

On Sun, Dec 08, 2024 at 12:30:30AM -0600, Mario Limonciello wrote:
> For Ryzen systems the EPP policy set by the BIOS is generally configured
> to performance as this is the default register value for the CPPC request
> MSR.
> 
> If a user doesn't use additional software to configure EPP then the system
> will default biased towards performance and consume extra battery. Instead
> configure the default to "balanced_performance" for this case.
> 
> Suggested-by: Artem S. Tashkinov <aros@gmx.com>
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219526
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Looks good to me for EPYC.

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

--
Thanks and Regards
gautham.

> ---
>  drivers/cpufreq/amd-pstate.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 5869bcd287e87..a4ededb8d89df 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1501,8 +1501,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  
>  	policy->driver_data = cpudata;
>  
> -	cpudata->epp_cached = cpudata->epp_default = amd_pstate_get_epp(cpudata);
> -
>  	policy->min = policy->cpuinfo.min_freq;
>  	policy->max = policy->cpuinfo.max_freq;
>  
> @@ -1513,10 +1511,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  	 * the default cpufreq governor is neither powersave nor performance.
>  	 */
>  	if (amd_pstate_acpi_pm_profile_server() ||
> -	    amd_pstate_acpi_pm_profile_undefined())
> +	    amd_pstate_acpi_pm_profile_undefined()) {
>  		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
> -	else
> +		cpudata->epp_default = amd_pstate_get_epp(cpudata);
> +	} else {
>  		policy->policy = CPUFREQ_POLICY_POWERSAVE;
> +		cpudata->epp_default = AMD_CPPC_EPP_BALANCE_PERFORMANCE;
> +	}
>  
>  	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
>  		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
> @@ -1529,6 +1530,9 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>  			return ret;
>  		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
>  	}
> +	ret = amd_pstate_set_epp(cpudata, cpudata->epp_default);
> +	if (ret)
> +		return ret;
>  
>  	current_pstate_driver->adjust_perf = NULL;
>  
> -- 
> 2.43.0
> 

[PATCH v2 16/16] cpufreq/amd-pstate: Drop boost_state variable

[Mario Limonciello]

Currently boost_state is cached for every processor in cpudata structure
and driver boost state is set for every processor.

Both of these aren't necessary as the driver only needs to set once and
the policy stores whether boost is enabled.

Move the driver boost setting to registration and adjust all references
to cached value to pull from the policy instead.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 26 +++++++++++++-------------
 drivers/cpufreq/amd-pstate.h |  1 -
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index a4ededb8d89df..3f6208828c063 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -315,9 +315,10 @@ static int shmem_set_epp(struct amd_cpudata *cpudata, u32 epp)
 	return ret;
 }
 
-static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
-		int pref_index)
+static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
+					    int pref_index)
 {
+	struct amd_cpudata *cpudata = policy->driver_data;
 	int epp;
 
 	if (!pref_index)
@@ -335,7 +336,7 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
 					  epp,
 					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
 					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
-					  cpudata->boost_state);
+					  policy->boost_enabled);
 	}
 
 	return amd_pstate_set_epp(cpudata, epp);
@@ -746,7 +747,6 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
 	guard(mutex)(&amd_pstate_driver_lock);
 
 	ret = amd_pstate_cpu_boost_update(policy, state);
-	WRITE_ONCE(cpudata->boost_state, !ret ? state : false);
 	policy->boost_enabled = !ret ? state : false;
 	refresh_frequency_limits(policy);
 
@@ -768,9 +768,6 @@ static int amd_pstate_init_boost_support(struct amd_cpudata *cpudata)
 		goto exit_err;
 	}
 
-	/* at least one CPU supports CPB, even if others fail later on to set up */
-	current_pstate_driver->boost_enabled = true;
-
 	ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
 	if (ret) {
 		pr_err_once("failed to read initial CPU boost state!\n");
@@ -1176,7 +1173,6 @@ 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;
 
@@ -1190,7 +1186,7 @@ static ssize_t store_energy_performance_preference(
 
 	guard(mutex)(&amd_pstate_limits_lock);
 
-	ret = amd_pstate_set_energy_pref_index(cpudata, ret);
+	ret = amd_pstate_set_energy_pref_index(policy, ret);
 
 	return ret ? ret : count;
 }
@@ -1265,6 +1261,9 @@ static int amd_pstate_register_driver(int mode)
 		return ret;
 	}
 
+	/* at least one CPU supports CPB */
+	current_pstate_driver->boost_enabled = cpu_feature_enabled(X86_FEATURE_CPB);
+
 	ret = cpufreq_register_driver(current_pstate_driver);
 	if (ret) {
 		amd_pstate_driver_cleanup();
@@ -1604,8 +1603,9 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
 	return 0;
 }
 
-static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
+static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
 {
+	struct amd_cpudata *cpudata = policy->driver_data;
 	u64 max_perf;
 	int ret;
 
@@ -1619,7 +1619,7 @@ static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
 		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
 					  cpudata->epp_cached,
 					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
-					  max_perf, cpudata->boost_state);
+					  max_perf, policy->boost_enabled);
 	}
 
 	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
@@ -1632,7 +1632,7 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
 
 	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
 
-	ret = amd_pstate_epp_reenable(cpudata);
+	ret = amd_pstate_epp_reenable(policy);
 	if (ret)
 		return ret;
 	cpudata->suspended = false;
@@ -1690,7 +1690,7 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
 		guard(mutex)(&amd_pstate_limits_lock);
 
 		/* enable amd pstate from suspend state*/
-		amd_pstate_epp_reenable(cpudata);
+		amd_pstate_epp_reenable(policy);
 
 		cpudata->suspended = false;
 	}
diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
index 7765c82f975c6..9747e3be6ceee 100644
--- a/drivers/cpufreq/amd-pstate.h
+++ b/drivers/cpufreq/amd-pstate.h
@@ -98,7 +98,6 @@ struct amd_cpudata {
 	u64	cppc_cap1_cached;
 	bool	suspended;
 	s16	epp_default;
-	bool	boost_state;
 };
 
 /*
-- 
2.43.0

Re: [PATCH v2 16/16] cpufreq/amd-pstate: Drop boost_state variable

[Gautham R. Shenoy]

Hello Mario,

On Sun, Dec 08, 2024 at 12:30:31AM -0600, Mario Limonciello wrote:
> Currently boost_state is cached for every processor in cpudata structure
> and driver boost state is set for every processor.
> 
> Both of these aren't necessary as the driver only needs to set once and
> the policy stores whether boost is enabled.
> 
> Move the driver boost setting to registration and adjust all references
> to cached value to pull from the policy instead.
> 
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>

Thanks for cleaning this up.

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

--
Thanks and Regards
gautham.

> ---
>  drivers/cpufreq/amd-pstate.c | 26 +++++++++++++-------------
>  drivers/cpufreq/amd-pstate.h |  1 -
>  2 files changed, 13 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index a4ededb8d89df..3f6208828c063 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -315,9 +315,10 @@ static int shmem_set_epp(struct amd_cpudata *cpudata, u32 epp)
>  	return ret;
>  }
>  
> -static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
> -		int pref_index)
> +static int amd_pstate_set_energy_pref_index(struct cpufreq_policy *policy,
> +					    int pref_index)
>  {
> +	struct amd_cpudata *cpudata = policy->driver_data;
>  	int epp;
>  
>  	if (!pref_index)
> @@ -335,7 +336,7 @@ static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
>  					  epp,
>  					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
>  					  FIELD_GET(AMD_CPPC_MAX_PERF_MASK, cpudata->cppc_req_cached),
> -					  cpudata->boost_state);
> +					  policy->boost_enabled);
>  	}
>  
>  	return amd_pstate_set_epp(cpudata, epp);
> @@ -746,7 +747,6 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
>  	guard(mutex)(&amd_pstate_driver_lock);
>  
>  	ret = amd_pstate_cpu_boost_update(policy, state);
> -	WRITE_ONCE(cpudata->boost_state, !ret ? state : false);
>  	policy->boost_enabled = !ret ? state : false;
>  	refresh_frequency_limits(policy);
>  
> @@ -768,9 +768,6 @@ static int amd_pstate_init_boost_support(struct amd_cpudata *cpudata)
>  		goto exit_err;
>  	}
>  
> -	/* at least one CPU supports CPB, even if others fail later on to set up */
> -	current_pstate_driver->boost_enabled = true;
> -
>  	ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
>  	if (ret) {
>  		pr_err_once("failed to read initial CPU boost state!\n");
> @@ -1176,7 +1173,6 @@ 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;
>  
> @@ -1190,7 +1186,7 @@ static ssize_t store_energy_performance_preference(
>  
>  	guard(mutex)(&amd_pstate_limits_lock);
>  
> -	ret = amd_pstate_set_energy_pref_index(cpudata, ret);
> +	ret = amd_pstate_set_energy_pref_index(policy, ret);
>  
>  	return ret ? ret : count;
>  }
> @@ -1265,6 +1261,9 @@ static int amd_pstate_register_driver(int mode)
>  		return ret;
>  	}
>  
> +	/* at least one CPU supports CPB */
> +	current_pstate_driver->boost_enabled = cpu_feature_enabled(X86_FEATURE_CPB);
> +
>  	ret = cpufreq_register_driver(current_pstate_driver);
>  	if (ret) {
>  		amd_pstate_driver_cleanup();
> @@ -1604,8 +1603,9 @@ static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
>  	return 0;
>  }
>  
> -static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
> +static int amd_pstate_epp_reenable(struct cpufreq_policy *policy)
>  {
> +	struct amd_cpudata *cpudata = policy->driver_data;
>  	u64 max_perf;
>  	int ret;
>  
> @@ -1619,7 +1619,7 @@ static int amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
>  		trace_amd_pstate_epp_perf(cpudata->cpu, cpudata->highest_perf,
>  					  cpudata->epp_cached,
>  					  FIELD_GET(AMD_CPPC_MIN_PERF_MASK, cpudata->cppc_req_cached),
> -					  max_perf, cpudata->boost_state);
> +					  max_perf, policy->boost_enabled);
>  	}
>  
>  	return amd_pstate_update_perf(cpudata, 0, 0, max_perf, cpudata->epp_cached, false);
> @@ -1632,7 +1632,7 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
>  
>  	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
>  
> -	ret = amd_pstate_epp_reenable(cpudata);
> +	ret = amd_pstate_epp_reenable(policy);
>  	if (ret)
>  		return ret;
>  	cpudata->suspended = false;
> @@ -1690,7 +1690,7 @@ static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
>  		guard(mutex)(&amd_pstate_limits_lock);
>  
>  		/* enable amd pstate from suspend state*/
> -		amd_pstate_epp_reenable(cpudata);
> +		amd_pstate_epp_reenable(policy);
>  
>  		cpudata->suspended = false;
>  	}
> diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
> index 7765c82f975c6..9747e3be6ceee 100644
> --- a/drivers/cpufreq/amd-pstate.h
> +++ b/drivers/cpufreq/amd-pstate.h
> @@ -98,7 +98,6 @@ struct amd_cpudata {
>  	u64	cppc_cap1_cached;
>  	bool	suspended;
>  	s16	epp_default;
> -	bool	boost_state;
>  };
>  
>  /*
> -- 
> 2.43.0
>