[PATCH v3 00/11] Adjustments for preferred core detection

[PATCH v3 00/11] Adjustments for preferred core detection

[Mario Limonciello]

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

Preferred core detection is fragile in that any CPU that reports
less than 255 for any core is assumed to be a preferred core design.
This might not always be true, so it's better to check all CPUs and
see that varying values are actually reported.

Furthermore, preferred core detection isn't used by acpi-cpufreq. So
incorrect frequencies are used unless amd-pstate is active.

This series moves preferred core detection out of amd-pstate in a more
robust fashion.  It also removes some tech debt of hardcoded values for
platforms that are actually preferred core platforms.

This branch is based off v6.11-rc6.

v2->v3:
 * Pick up tags
 * Fix LKP reported issue
Mario Limonciello (11):
  x86/amd: Move amd_get_highest_perf() from amd.c to cppc.c
  ACPI: CPPC: Adjust return code for inline functions in
    !CONFIG_ACPI_CPPC_LIB
  x86/amd: Rename amd_get_highest_perf() to
    amd_get_boost_ratio_numerator()
  ACPI: CPPC: Drop check for non zero perf ratio
  ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn
  x86/amd: Move amd_get_highest_perf() out of amd-pstate
  x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()
  cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into
    amd_get_boost_ratio_numerator()
  cpufreq: amd-pstate: Optimize amd_pstate_update_limits()
  cpufreq: amd-pstate: Add documentation for `amd_pstate_hw_prefcore`
  amd-pstate: Add missing documentation for
    `amd_pstate_prefcore_ranking`

 Documentation/admin-guide/pm/amd-pstate.rst |  15 +-
 arch/x86/include/asm/processor.h            |   3 -
 arch/x86/kernel/acpi/cppc.c                 | 172 ++++++++++++++++++--
 arch/x86/kernel/cpu/amd.c                   |  16 --
 drivers/cpufreq/acpi-cpufreq.c              |  12 +-
 drivers/cpufreq/amd-pstate.c                | 128 ++++-----------
 include/acpi/cppc_acpi.h                    |  41 +++--
 7 files changed, 241 insertions(+), 146 deletions(-)

-- 
2.43.0

[PATCH v3 01/11] x86/amd: Move amd_get_highest_perf() from amd.c to cppc.c

[Mario Limonciello]

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

To prepare to let amd_get_highest_perf() detect preferred cores
it will require CPPC functions. Move amd_get_highest_perf() to
cppc.c to prepare for 'preferred core detection' rework.

No functional changes intended.

Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 arch/x86/kernel/acpi/cppc.c | 16 ++++++++++++++++
 arch/x86/kernel/cpu/amd.c   | 16 ----------------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index ff8f25faca3dd..7ec8f2ce859c8 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -116,3 +116,19 @@ void init_freq_invariance_cppc(void)
 	init_done = true;
 	mutex_unlock(&freq_invariance_lock);
 }
+
+u32 amd_get_highest_perf(void)
+{
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+
+	if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
+			       (c->x86_model >= 0x70 && c->x86_model < 0x80)))
+		return 166;
+
+	if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
+			       (c->x86_model >= 0x40 && c->x86_model < 0x70)))
+		return 166;
+
+	return 255;
+}
+EXPORT_SYMBOL_GPL(amd_get_highest_perf);
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 1e0fe5f8ab84e..015971adadfc7 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -1190,22 +1190,6 @@ unsigned long amd_get_dr_addr_mask(unsigned int dr)
 }
 EXPORT_SYMBOL_GPL(amd_get_dr_addr_mask);
 
-u32 amd_get_highest_perf(void)
-{
-	struct cpuinfo_x86 *c = &boot_cpu_data;
-
-	if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
-			       (c->x86_model >= 0x70 && c->x86_model < 0x80)))
-		return 166;
-
-	if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
-			       (c->x86_model >= 0x40 && c->x86_model < 0x70)))
-		return 166;
-
-	return 255;
-}
-EXPORT_SYMBOL_GPL(amd_get_highest_perf);
-
 static void zenbleed_check_cpu(void *unused)
 {
 	struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
-- 
2.43.0

[PATCH v3 02/11] ACPI: CPPC: Adjust return code for inline functions in !CONFIG_ACPI_CPPC_LIB

[Mario Limonciello]

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

Checkpath emits the following warning:
```
WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP
```

Adjust the code accordingly.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2->v3:
 * Pick up tag
---
 include/acpi/cppc_acpi.h | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 930b6afba6f4d..409a7190a4a86 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -162,31 +162,31 @@ extern int cppc_set_auto_sel(int cpu, bool enable);
 #else /* !CONFIG_ACPI_CPPC_LIB */
 static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_get_nominal_perf(int cpunum, u64 *nominal_perf)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_get_highest_perf(int cpunum, u64 *highest_perf)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_set_enable(int cpu, bool enable)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline bool cppc_perf_ctrs_in_pcc(void)
 {
@@ -210,27 +210,27 @@ static inline bool cpc_ffh_supported(void)
 }
 static inline int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_get_epp_perf(int cpunum, u64 *epp_perf)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_set_auto_sel(int cpu, bool enable)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 static inline int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 {
-	return -ENOTSUPP;
+	return -EOPNOTSUPP;
 }
 #endif /* !CONFIG_ACPI_CPPC_LIB */
 
-- 
2.43.0

[PATCH v3 03/11] x86/amd: Rename amd_get_highest_perf() to amd_get_boost_ratio_numerator()

[Mario Limonciello]

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

The function name is ambiguous because it returns an intermediate value
for calculating maximum frequency rather than the CPPC 'Highest Perf'
register.

Rename the function to clarify its use and allow the function to return
errors. Adjust the consumer in acpi-cpufreq to catch errors.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v1->v2:
 * Rename variable from `highest_perf` to `numerator`
 * Fail when unable to return boost numerator
 * Move prototype behind CONFIG_ACPI_CPPC_LIB (lkp robot)
v2->v3:
 * Pick up tag
---
 arch/x86/include/asm/processor.h |  3 ---
 arch/x86/kernel/acpi/cppc.c      | 44 +++++++++++++++++++++++---------
 drivers/cpufreq/acpi-cpufreq.c   | 12 ++++++---
 include/acpi/cppc_acpi.h         |  5 ++++
 4 files changed, 46 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index a75a07f4931fd..775acbdea1a96 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -691,8 +691,6 @@ static inline u32 per_cpu_l2c_id(unsigned int cpu)
 }
 
 #ifdef CONFIG_CPU_SUP_AMD
-extern u32 amd_get_highest_perf(void);
-
 /*
  * Issue a DIV 0/1 insn to clear any division data from previous DIV
  * operations.
@@ -705,7 +703,6 @@ static __always_inline void amd_clear_divider(void)
 
 extern void amd_check_microcode(void);
 #else
-static inline u32 amd_get_highest_perf(void)		{ return 0; }
 static inline void amd_clear_divider(void)		{ }
 static inline void amd_check_microcode(void)		{ }
 #endif
diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index 7ec8f2ce859c8..660cfeb6384ba 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -69,7 +69,7 @@ int cpc_write_ffh(int cpunum, struct cpc_reg *reg, u64 val)
 static void amd_set_max_freq_ratio(void)
 {
 	struct cppc_perf_caps perf_caps;
-	u64 highest_perf, nominal_perf;
+	u64 numerator, nominal_perf;
 	u64 perf_ratio;
 	int rc;
 
@@ -79,15 +79,19 @@ static void amd_set_max_freq_ratio(void)
 		return;
 	}
 
-	highest_perf = amd_get_highest_perf();
+	rc = amd_get_boost_ratio_numerator(0, &numerator);
+	if (rc) {
+		pr_debug("Could not retrieve highest performance (%d)\n", rc);
+		return;
+	}
 	nominal_perf = perf_caps.nominal_perf;
 
-	if (!highest_perf || !nominal_perf) {
-		pr_debug("Could not retrieve highest or nominal performance\n");
+	if (!nominal_perf) {
+		pr_debug("Could not retrieve nominal performance\n");
 		return;
 	}
 
-	perf_ratio = div_u64(highest_perf * SCHED_CAPACITY_SCALE, nominal_perf);
+	perf_ratio = div_u64(numerator * SCHED_CAPACITY_SCALE, nominal_perf);
 	/* midpoint between max_boost and max_P */
 	perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
 	if (!perf_ratio) {
@@ -117,18 +121,34 @@ void init_freq_invariance_cppc(void)
 	mutex_unlock(&freq_invariance_lock);
 }
 
-u32 amd_get_highest_perf(void)
+/**
+ * amd_get_boost_ratio_numerator: Get the numerator to use for boost ratio calculation
+ * @cpu: CPU to get numerator for.
+ * @numerator: Output variable for numerator.
+ *
+ * Determine the numerator to use for calculating the boost ratio on
+ * a CPU. On systems that support preferred cores, this will be a hardcoded
+ * value. On other systems this will the highest performance register value.
+ *
+ * Return: 0 for success, negative error code otherwise.
+ */
+int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
 {
 	struct cpuinfo_x86 *c = &boot_cpu_data;
 
 	if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
-			       (c->x86_model >= 0x70 && c->x86_model < 0x80)))
-		return 166;
+			       (c->x86_model >= 0x70 && c->x86_model < 0x80))) {
+		*numerator = 166;
+		return 0;
+	}
 
 	if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
-			       (c->x86_model >= 0x40 && c->x86_model < 0x70)))
-		return 166;
+			       (c->x86_model >= 0x40 && c->x86_model < 0x70))) {
+		*numerator = 166;
+		return 0;
+	}
+	*numerator = 255;
 
-	return 255;
+	return 0;
 }
-EXPORT_SYMBOL_GPL(amd_get_highest_perf);
+EXPORT_SYMBOL_GPL(amd_get_boost_ratio_numerator);
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index a8ca625a98b89..0f04feb6cafaf 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -642,10 +642,16 @@ static u64 get_max_boost_ratio(unsigned int cpu)
 		return 0;
 	}
 
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
-		highest_perf = amd_get_highest_perf();
-	else
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+		ret = amd_get_boost_ratio_numerator(cpu, &highest_perf);
+		if (ret) {
+			pr_debug("CPU%d: Unable to get boost ratio numerator (%d)\n",
+				 cpu, ret);
+			return 0;
+		}
+	} else {
 		highest_perf = perf_caps.highest_perf;
+	}
 
 	nominal_perf = perf_caps.nominal_perf;
 
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 409a7190a4a86..97861abc5f5b8 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -159,6 +159,7 @@ extern int cppc_get_epp_perf(int cpunum, u64 *epp_perf);
 extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable);
 extern int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps);
 extern int cppc_set_auto_sel(int cpu, bool enable);
+extern int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator);
 #else /* !CONFIG_ACPI_CPPC_LIB */
 static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
 {
@@ -232,6 +233,10 @@ static inline int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf
 {
 	return -EOPNOTSUPP;
 }
+static inline int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
+{
+	return -EOPNOTSUPP;
+}
 #endif /* !CONFIG_ACPI_CPPC_LIB */
 
 #endif /* _CPPC_ACPI_H*/
-- 
2.43.0

[PATCH v3 04/11] ACPI: CPPC: Drop check for non zero perf ratio

[Mario Limonciello]

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

perf_ratio is a u64 and SCHED_CAPACITY_SCALE is a large number.
Shifting by one will never have a zero value.

Drop the check.

Suggested-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.sheoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2->v3:
 * Correct typo in commit message
 * Pick up tag
---
 arch/x86/kernel/acpi/cppc.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index 660cfeb6384ba..e65c77afab318 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -91,13 +91,8 @@ static void amd_set_max_freq_ratio(void)
 		return;
 	}
 
-	perf_ratio = div_u64(numerator * SCHED_CAPACITY_SCALE, nominal_perf);
 	/* midpoint between max_boost and max_P */
-	perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
-	if (!perf_ratio) {
-		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
-		return;
-	}
+	perf_ratio = (div_u64(numerator * SCHED_CAPACITY_SCALE, nominal_perf) + SCHED_CAPACITY_SCALE) >> 1;
 
 	freq_invariance_set_perf_ratio(perf_ratio, false);
 }
-- 
2.43.0

[PATCH v3 05/11] ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn

[Mario Limonciello]

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

If the boost ratio isn't calculated properly for the system for any
reason this can cause other problems that are non-obvious.

Raise all messages to warn instead.

Suggested-by: Perry Yuan <Perry.Yuan@amd.com>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 arch/x86/kernel/acpi/cppc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index e65c77afab318..f0328ce98a8fe 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -75,19 +75,19 @@ static void amd_set_max_freq_ratio(void)
 
 	rc = cppc_get_perf_caps(0, &perf_caps);
 	if (rc) {
-		pr_debug("Could not retrieve perf counters (%d)\n", rc);
+		pr_warn("Could not retrieve perf counters (%d)\n", rc);
 		return;
 	}
 
 	rc = amd_get_boost_ratio_numerator(0, &numerator);
 	if (rc) {
-		pr_debug("Could not retrieve highest performance (%d)\n", rc);
+		pr_warn("Could not retrieve highest performance (%d)\n", rc);
 		return;
 	}
 	nominal_perf = perf_caps.nominal_perf;
 
 	if (!nominal_perf) {
-		pr_debug("Could not retrieve nominal performance\n");
+		pr_warn("Could not retrieve nominal performance\n");
 		return;
 	}
 
-- 
2.43.0

[PATCH v3 06/11] x86/amd: Move amd_get_highest_perf() out of amd-pstate

[Mario Limonciello]

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

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

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

Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v1->v2:
 * Update commit message (Gautham)
---
 arch/x86/kernel/acpi/cppc.c  | 30 ++++++++++++++++++++++++++++++
 drivers/cpufreq/amd-pstate.c | 34 ++--------------------------------
 include/acpi/cppc_acpi.h     |  5 +++++
 3 files changed, 37 insertions(+), 32 deletions(-)

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index f0328ce98a8fe..a75dcb382c786 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -116,6 +116,36 @@ void init_freq_invariance_cppc(void)
 	mutex_unlock(&freq_invariance_lock);
 }
 
+/*
+ * Get the highest performance register value.
+ * @cpu: CPU from which to get highest performance.
+ * @highest_perf: Return address for highest performance value.
+ *
+ * Return: 0 for success, negative error code otherwise.
+ */
+int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
+{
+	u64 val;
+	int ret;
+
+	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
+		ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &val);
+		if (ret)
+			goto out;
+
+		val = AMD_CPPC_HIGHEST_PERF(val);
+	} else {
+		ret = cppc_get_highest_perf(cpu, &val);
+		if (ret)
+			goto out;
+	}
+
+	WRITE_ONCE(*highest_perf, (u32)val);
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(amd_get_highest_perf);
+
 /**
  * amd_get_boost_ratio_numerator: Get the numerator to use for boost ratio calculation
  * @cpu: CPU to get numerator for.
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index db4f747f128f1..44df6ef66b5fa 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -803,36 +803,6 @@ static void amd_pstste_sched_prefcore_workfn(struct work_struct *work)
 }
 static DECLARE_WORK(sched_prefcore_work, amd_pstste_sched_prefcore_workfn);
 
-/*
- * Get the highest performance register value.
- * @cpu: CPU from which to get highest performance.
- * @highest_perf: Return address.
- *
- * Return: 0 for success, -EIO otherwise.
- */
-static int amd_pstate_get_highest_perf(int cpu, u32 *highest_perf)
-{
-	int ret;
-
-	if (cpu_feature_enabled(X86_FEATURE_CPPC)) {
-		u64 cap1;
-
-		ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
-		if (ret)
-			return ret;
-		WRITE_ONCE(*highest_perf, AMD_CPPC_HIGHEST_PERF(cap1));
-	} else {
-		u64 cppc_highest_perf;
-
-		ret = cppc_get_highest_perf(cpu, &cppc_highest_perf);
-		if (ret)
-			return ret;
-		WRITE_ONCE(*highest_perf, cppc_highest_perf);
-	}
-
-	return (ret);
-}
-
 #define CPPC_MAX_PERF	U8_MAX
 
 static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
@@ -840,7 +810,7 @@ static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
 	int ret, prio;
 	u32 highest_perf;
 
-	ret = amd_pstate_get_highest_perf(cpudata->cpu, &highest_perf);
+	ret = amd_get_highest_perf(cpudata->cpu, &highest_perf);
 	if (ret)
 		return;
 
@@ -879,7 +849,7 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
 		goto free_cpufreq_put;
 
-	ret = amd_pstate_get_highest_perf(cpu, &cur_high);
+	ret = amd_get_highest_perf(cpu, &cur_high);
 	if (ret)
 		goto free_cpufreq_put;
 
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 97861abc5f5b8..f7c7abf2a95e9 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -159,6 +159,7 @@ extern int cppc_get_epp_perf(int cpunum, u64 *epp_perf);
 extern int cppc_set_epp_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls, bool enable);
 extern int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps);
 extern int cppc_set_auto_sel(int cpu, bool enable);
+extern int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf);
 extern int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator);
 #else /* !CONFIG_ACPI_CPPC_LIB */
 static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
@@ -233,6 +234,10 @@ static inline int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf
 {
 	return -EOPNOTSUPP;
 }
+static inline int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
+{
+	return -ENODEV;
+}
 static inline int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
 {
 	return -EOPNOTSUPP;
-- 
2.43.0

[PATCH v3 07/11] x86/amd: Detect preferred cores in amd_get_boost_ratio_numerator()

[Mario Limonciello]

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

AMD systems that support preferred cores will use "166" as their
numerator for max frequency calculations instead of "255".

Add a function for detecting preferred cores by looking at the
highest perf value on all cores.

If preferred cores are enabled return 166 and if disabled the
value in the highest perf register. As the function will be called
multiple times, cache the values for the boost numerator and if
preferred cores will be enabled in global variables.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v1->v2:
 * Add a comment into amd_get_boost_ratio_numerator() as well
v2->v3:
 * Fix kernel robot error
---
 arch/x86/kernel/acpi/cppc.c  | 93 ++++++++++++++++++++++++++++++++----
 drivers/cpufreq/amd-pstate.c | 34 +++++--------
 include/acpi/cppc_acpi.h     |  5 ++
 3 files changed, 101 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index a75dcb382c786..df367bc359308 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -9,6 +9,16 @@
 #include <asm/processor.h>
 #include <asm/topology.h>
 
+#define CPPC_HIGHEST_PERF_PREFCORE	166
+
+enum amd_pref_core {
+	AMD_PREF_CORE_UNKNOWN = 0,
+	AMD_PREF_CORE_SUPPORTED,
+	AMD_PREF_CORE_UNSUPPORTED,
+};
+static enum amd_pref_core amd_pref_core_detected;
+static u64 boost_numerator;
+
 /* Refer to drivers/acpi/cppc_acpi.c for the description of functions */
 
 bool cpc_supported_by_cpu(void)
@@ -146,6 +156,66 @@ int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf)
 }
 EXPORT_SYMBOL_GPL(amd_get_highest_perf);
 
+/**
+ * amd_detect_prefcore: Detect if CPUs in the system support preferred cores
+ * @detected: Output variable for the result of the detection.
+ *
+ * Determine whether CPUs in the system support preferred cores. On systems
+ * that support preferred cores, different highest perf values will be found
+ * on different cores. On other systems, the highest perf value will be the
+ * same on all cores.
+ *
+ * The result of the detection will be stored in the 'detected' parameter.
+ *
+ * Return: 0 for success, negative error code otherwise
+ */
+int amd_detect_prefcore(bool *detected)
+{
+	int cpu, count = 0;
+	u64 highest_perf[2] = {0};
+
+	if (WARN_ON(!detected))
+		return -EINVAL;
+
+	switch (amd_pref_core_detected) {
+	case AMD_PREF_CORE_SUPPORTED:
+		*detected = true;
+		return 0;
+	case AMD_PREF_CORE_UNSUPPORTED:
+		*detected = false;
+		return 0;
+	default:
+		break;
+	}
+
+	for_each_present_cpu(cpu) {
+		u32 tmp;
+		int ret;
+
+		ret = amd_get_highest_perf(cpu, &tmp);
+		if (ret)
+			return ret;
+
+		if (!count || (count == 1 && tmp != highest_perf[0]))
+			highest_perf[count++] = tmp;
+
+		if (count == 2)
+			break;
+	}
+
+	*detected = (count == 2);
+	boost_numerator = highest_perf[0];
+
+	amd_pref_core_detected = *detected ? AMD_PREF_CORE_SUPPORTED :
+					     AMD_PREF_CORE_UNSUPPORTED;
+
+	pr_debug("AMD CPPC preferred core is %ssupported (highest perf: 0x%llx)\n",
+		 *detected ? "" : "un", highest_perf[0]);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(amd_detect_prefcore);
+
 /**
  * amd_get_boost_ratio_numerator: Get the numerator to use for boost ratio calculation
  * @cpu: CPU to get numerator for.
@@ -155,24 +225,27 @@ EXPORT_SYMBOL_GPL(amd_get_highest_perf);
  * a CPU. On systems that support preferred cores, this will be a hardcoded
  * value. On other systems this will the highest performance register value.
  *
+ * If booting the system with amd-pstate enabled but preferred cores disabled then
+ * the correct boost numerator will be returned to match hardware capabilities
+ * even if the preferred cores scheduling hints are not enabled.
+ *
  * Return: 0 for success, negative error code otherwise.
  */
 int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
 {
-	struct cpuinfo_x86 *c = &boot_cpu_data;
+	bool prefcore;
+	int ret;
 
-	if (c->x86 == 0x17 && ((c->x86_model >= 0x30 && c->x86_model < 0x40) ||
-			       (c->x86_model >= 0x70 && c->x86_model < 0x80))) {
-		*numerator = 166;
-		return 0;
-	}
+	ret = amd_detect_prefcore(&prefcore);
+	if (ret)
+		return ret;
 
-	if (c->x86 == 0x19 && ((c->x86_model >= 0x20 && c->x86_model < 0x30) ||
-			       (c->x86_model >= 0x40 && c->x86_model < 0x70))) {
-		*numerator = 166;
+	/* without preferred cores, return the highest perf register value */
+	if (!prefcore) {
+		*numerator = boost_numerator;
 		return 0;
 	}
-	*numerator = 255;
+	*numerator = CPPC_HIGHEST_PERF_PREFCORE;
 
 	return 0;
 }
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 44df6ef66b5fa..c29cdf2d3882c 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -807,32 +807,18 @@ static DECLARE_WORK(sched_prefcore_work, amd_pstste_sched_prefcore_workfn);
 
 static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
 {
-	int ret, prio;
-	u32 highest_perf;
-
-	ret = amd_get_highest_perf(cpudata->cpu, &highest_perf);
-	if (ret)
+	/* user disabled or not detected */
+	if (!amd_pstate_prefcore)
 		return;
 
 	cpudata->hw_prefcore = true;
-	/* check if CPPC preferred core feature is enabled*/
-	if (highest_perf < CPPC_MAX_PERF)
-		prio = (int)highest_perf;
-	else {
-		pr_debug("AMD CPPC preferred core is unsupported!\n");
-		cpudata->hw_prefcore = false;
-		return;
-	}
-
-	if (!amd_pstate_prefcore)
-		return;
 
 	/*
 	 * The priorities can be set regardless of whether or not
 	 * sched_set_itmt_support(true) has been called and it is valid to
 	 * update them at any time after it has been called.
 	 */
-	sched_set_itmt_core_prio(prio, cpudata->cpu);
+	sched_set_itmt_core_prio((int)READ_ONCE(cpudata->highest_perf), cpudata->cpu);
 
 	schedule_work(&sched_prefcore_work);
 }
@@ -998,12 +984,12 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 
 	cpudata->cpu = policy->cpu;
 
-	amd_pstate_init_prefcore(cpudata);
-
 	ret = amd_pstate_init_perf(cpudata);
 	if (ret)
 		goto free_cpudata1;
 
+	amd_pstate_init_prefcore(cpudata);
+
 	ret = amd_pstate_init_freq(cpudata);
 	if (ret)
 		goto free_cpudata1;
@@ -1453,12 +1439,12 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	cpudata->cpu = policy->cpu;
 	cpudata->epp_policy = 0;
 
-	amd_pstate_init_prefcore(cpudata);
-
 	ret = amd_pstate_init_perf(cpudata);
 	if (ret)
 		goto free_cpudata1;
 
+	amd_pstate_init_prefcore(cpudata);
+
 	ret = amd_pstate_init_freq(cpudata);
 	if (ret)
 		goto free_cpudata1;
@@ -1920,6 +1906,12 @@ static int __init amd_pstate_init(void)
 		static_call_update(amd_pstate_update_perf, cppc_update_perf);
 	}
 
+	if (amd_pstate_prefcore) {
+		ret = amd_detect_prefcore(&amd_pstate_prefcore);
+		if (ret)
+			return ret;
+	}
+
 	/* enable amd pstate feature */
 	ret = amd_pstate_enable(true);
 	if (ret) {
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index f7c7abf2a95e9..482e0587a0413 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -161,6 +161,7 @@ extern int cppc_get_auto_sel_caps(int cpunum, struct cppc_perf_caps *perf_caps);
 extern int cppc_set_auto_sel(int cpu, bool enable);
 extern int amd_get_highest_perf(unsigned int cpu, u32 *highest_perf);
 extern int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator);
+extern int amd_detect_prefcore(bool *detected);
 #else /* !CONFIG_ACPI_CPPC_LIB */
 static inline int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
 {
@@ -242,6 +243,10 @@ static inline int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator
 {
 	return -EOPNOTSUPP;
 }
+static inline int amd_detect_prefcore(bool *detected)
+{
+	return -ENODEV;
+}
 #endif /* !CONFIG_ACPI_CPPC_LIB */
 
 #endif /* _CPPC_ACPI_H*/
-- 
2.43.0

[PATCH v3 08/11] cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()

[Mario Limonciello]

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

The special case in amd_pstate_highest_perf_set() is the value used
for calculating the boost numerator.  Merge this into
amd_get_boost_ratio_numerator() and then use that to calculate boost
ratio.

This allows dropping more special casing of the highest perf value.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2->v3:
 * Add tag
v1->v2:
 * Document that preferred cores will have different values for highest
   perf.
 * Fix an uninitialized variable caused by merge
---
 Documentation/admin-guide/pm/amd-pstate.rst |  3 +-
 arch/x86/kernel/acpi/cppc.c                 | 16 +++++++
 drivers/cpufreq/amd-pstate.c                | 52 ++++-----------------
 3 files changed, 28 insertions(+), 43 deletions(-)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index d0324d44f5482..e13915c540648 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -251,7 +251,8 @@ 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``.
+``cpuinfo``. On systems that support preferred core, the driver will have
+different values for some cores than others.
 This attribute is read-only.
 
 ``amd_pstate_lowest_nonlinear_freq``
diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index df367bc359308..956984054bf30 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -9,6 +9,7 @@
 #include <asm/processor.h>
 #include <asm/topology.h>
 
+#define CPPC_HIGHEST_PERF_PERFORMANCE	196
 #define CPPC_HIGHEST_PERF_PREFCORE	166
 
 enum amd_pref_core {
@@ -245,6 +246,21 @@ int amd_get_boost_ratio_numerator(unsigned int cpu, u64 *numerator)
 		*numerator = boost_numerator;
 		return 0;
 	}
+
+	/*
+	 * For AMD CPUs with Family ID 19H and Model ID range 0x70 to 0x7f,
+	 * the highest performance level is set to 196.
+	 * https://bugzilla.kernel.org/show_bug.cgi?id=218759
+	 */
+	if (cpu_feature_enabled(X86_FEATURE_ZEN4)) {
+		switch (boot_cpu_data.x86_model) {
+		case 0x70 ... 0x7f:
+			*numerator = CPPC_HIGHEST_PERF_PERFORMANCE;
+			return 0;
+		default:
+			break;
+		}
+	}
 	*numerator = CPPC_HIGHEST_PERF_PREFCORE;
 
 	return 0;
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index c29cdf2d3882c..3ae41af6f041e 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -52,8 +52,6 @@
 #define AMD_PSTATE_TRANSITION_LATENCY	20000
 #define AMD_PSTATE_TRANSITION_DELAY	1000
 #define AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY 600
-#define CPPC_HIGHEST_PERF_PERFORMANCE	196
-#define CPPC_HIGHEST_PERF_DEFAULT	166
 
 #define AMD_CPPC_EPP_PERFORMANCE		0x00
 #define AMD_CPPC_EPP_BALANCE_PERFORMANCE	0x80
@@ -372,43 +370,17 @@ static inline int amd_pstate_enable(bool enable)
 	return static_call(amd_pstate_enable)(enable);
 }
 
-static u32 amd_pstate_highest_perf_set(struct amd_cpudata *cpudata)
-{
-	struct cpuinfo_x86 *c = &cpu_data(0);
-
-	/*
-	 * For AMD CPUs with Family ID 19H and Model ID range 0x70 to 0x7f,
-	 * the highest performance level is set to 196.
-	 * https://bugzilla.kernel.org/show_bug.cgi?id=218759
-	 */
-	if (c->x86 == 0x19 && (c->x86_model >= 0x70 && c->x86_model <= 0x7f))
-		return CPPC_HIGHEST_PERF_PERFORMANCE;
-
-	return CPPC_HIGHEST_PERF_DEFAULT;
-}
-
 static int pstate_init_perf(struct amd_cpudata *cpudata)
 {
 	u64 cap1;
-	u32 highest_perf;
 
 	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
 				     &cap1);
 	if (ret)
 		return ret;
 
-	/* For platforms that do not support the preferred core feature, the
-	 * highest_pef may be configured with 166 or 255, to avoid max frequency
-	 * calculated wrongly. we take the AMD_CPPC_HIGHEST_PERF(cap1) value as
-	 * the default max perf.
-	 */
-	if (cpudata->hw_prefcore)
-		highest_perf = amd_pstate_highest_perf_set(cpudata);
-	else
-		highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
-
-	WRITE_ONCE(cpudata->highest_perf, highest_perf);
-	WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
+	WRITE_ONCE(cpudata->highest_perf, AMD_CPPC_HIGHEST_PERF(cap1));
+	WRITE_ONCE(cpudata->max_limit_perf, AMD_CPPC_HIGHEST_PERF(cap1));
 	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));
@@ -420,19 +392,13 @@ static int pstate_init_perf(struct amd_cpudata *cpudata)
 static int cppc_init_perf(struct amd_cpudata *cpudata)
 {
 	struct cppc_perf_caps cppc_perf;
-	u32 highest_perf;
 
 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
 	if (ret)
 		return ret;
 
-	if (cpudata->hw_prefcore)
-		highest_perf = amd_pstate_highest_perf_set(cpudata);
-	else
-		highest_perf = cppc_perf.highest_perf;
-
-	WRITE_ONCE(cpudata->highest_perf, highest_perf);
-	WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
+	WRITE_ONCE(cpudata->highest_perf, cppc_perf.highest_perf);
+	WRITE_ONCE(cpudata->max_limit_perf, cppc_perf.highest_perf);
 	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
 	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
 		   cppc_perf.lowest_nonlinear_perf);
@@ -905,8 +871,8 @@ static u32 amd_pstate_get_transition_latency(unsigned int cpu)
 static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 {
 	int ret;
-	u32 min_freq;
-	u32 highest_perf, max_freq;
+	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;
@@ -928,8 +894,10 @@ static int amd_pstate_init_freq(struct amd_cpudata *cpudata)
 
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 
-	highest_perf = READ_ONCE(cpudata->highest_perf);
-	boost_ratio = div_u64(highest_perf << SCHED_CAPACITY_SHIFT, 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);
 	max_freq = (nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT) * 1000;
 
 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
-- 
2.43.0

[PATCH v3 09/11] cpufreq: amd-pstate: Optimize amd_pstate_update_limits()

[Mario Limonciello]

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

Don't take and release the mutex when prefcore isn't present and
avoid initialization of variables that will be initially set
in the function.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 3ae41af6f041e..9312d4e40994f 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -797,17 +797,17 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	int ret;
 	bool highest_perf_changed = false;
 
-	mutex_lock(&amd_pstate_driver_lock);
-	if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
-		goto free_cpufreq_put;
+	if (!amd_pstate_prefcore)
+		return;
 
+	mutex_lock(&amd_pstate_driver_lock);
 	ret = amd_get_highest_perf(cpu, &cur_high);
 	if (ret)
 		goto free_cpufreq_put;
 
 	prev_high = READ_ONCE(cpudata->prefcore_ranking);
-	if (prev_high != cur_high) {
-		highest_perf_changed = true;
+	highest_perf_changed = (prev_high != cur_high);
+	if (highest_perf_changed) {
 		WRITE_ONCE(cpudata->prefcore_ranking, cur_high);
 
 		if (cur_high < CPPC_MAX_PERF)
-- 
2.43.0

[PATCH v3 10/11] cpufreq: amd-pstate: Add documentation for `amd_pstate_hw_prefcore`

[Mario Limonciello]

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

Explain that the sysfs file represents both preferred core being
enabled by the user and supported by the hardware.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2->v3:
 * Add tag
---
 Documentation/admin-guide/pm/amd-pstate.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index e13915c540648..d5c050ea390dc 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -263,6 +263,11 @@ lowest non-linear performance in `AMD CPPC Performance Capability
 <perf_cap_>`_.)
 This attribute is read-only.
 
+``amd_pstate_hw_prefcore``
+
+Whether the platform supports the preferred core feature and it has been
+enabled. This attribute is read-only.
+
 ``energy_performance_available_preferences``
 
 A list of all the supported EPP preferences that could be used for
-- 
2.43.0

[PATCH v3 11/11] amd-pstate: Add missing documentation for `amd_pstate_prefcore_ranking`

[Mario Limonciello]

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

`amd_pstate_prefcore_ranking` reflects the dynamic rankings of a CPU
core based on platform conditions.  Explicitly include it in the
documentation.

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
v2->v3:
 * Add tag
---
 Documentation/admin-guide/pm/amd-pstate.rst | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index d5c050ea390dc..210a808b74ec2 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -252,7 +252,8 @@ 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.
+different values for some cores than others and this will reflect the values
+advertised by the platform at bootup.
 This attribute is read-only.
 
 ``amd_pstate_lowest_nonlinear_freq``
@@ -268,6 +269,12 @@ This attribute is read-only.
 Whether the platform supports the preferred core feature and it has been
 enabled. This attribute is read-only.
 
+``amd_pstate_prefcore_ranking``
+
+The performance ranking of the core. This number doesn't have any unit, but
+larger numbers are preferred at the time of reading. This can change at
+runtime based on platform conditions. This attribute is read-only.
+
 ``energy_performance_available_preferences``
 
 A list of all the supported EPP preferences that could be used for
-- 
2.43.0

Re: [PATCH v3 10/11] cpufreq: amd-pstate: Add documentation for `amd_pstate_hw_prefcore`

[Russell Haley]

On 9/5/24 11:30 AM, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> Explain that the sysfs file represents both preferred core being
> enabled by the user and supported by the hardware.
> 
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
> v2->v3:
>  * Add tag
> ---
>  Documentation/admin-guide/pm/amd-pstate.rst | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
> index e13915c540648..d5c050ea390dc 100644
> --- a/Documentation/admin-guide/pm/amd-pstate.rst
> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
> @@ -263,6 +263,11 @@ lowest non-linear performance in `AMD CPPC Performance Capability
>  <perf_cap_>`_.)
>  This attribute is read-only.
>  
> +``amd_pstate_hw_prefcore``
> +
> +Whether the platform supports the preferred core feature and it has been
> +enabled. This attribute is read-only.
> +
>  ``energy_performance_available_preferences``
>  
>  A list of all the supported EPP preferences that could be used for

I notice I am confused. If the attribute is read only, how can it be
enabled by the user?

Re: [PATCH v3 10/11] cpufreq: amd-pstate: Add documentation for `amd_pstate_hw_prefcore`

[Mario Limonciello]

On 9/10/2024 05:19, Russell Haley wrote:
> On 9/5/24 11:30 AM, Mario Limonciello wrote:
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> Explain that the sysfs file represents both preferred core being
>> enabled by the user and supported by the hardware.
>>
>> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>> v2->v3:
>>   * Add tag
>> ---
>>   Documentation/admin-guide/pm/amd-pstate.rst | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
>> index e13915c540648..d5c050ea390dc 100644
>> --- a/Documentation/admin-guide/pm/amd-pstate.rst
>> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
>> @@ -263,6 +263,11 @@ lowest non-linear performance in `AMD CPPC Performance Capability
>>   <perf_cap_>`_.)
>>   This attribute is read-only.
>>   
>> +``amd_pstate_hw_prefcore``
>> +
>> +Whether the platform supports the preferred core feature and it has been
>> +enabled. This attribute is read-only.
>> +
>>   ``energy_performance_available_preferences``
>>   
>>   A list of all the supported EPP preferences that could be used for
> 
> I notice I am confused. If the attribute is read only, how can it be
> enabled by the user?

It is enabled by default.  It can be disabled by the user via the kernel 
command line:

amd_prefcore=disable

This is documented separately in kernel-parameters.txt.

Re: [PATCH v3 00/11] Adjustments for preferred core detection

[Ivan Shapovalov]

Hi,

On my desktop Zen 3 (Vermeer) system applying this series yields a new
warning message on each boot:

> Oct 16 06:20:41 kernel: Could not retrieve highest performance (-19)

As I see it, this is one of the pr_debug()s newly promoted to warnings.
Is there anything I can provide to help fix this?

Just for completeness:

```
$ cat-files /sys/devices/system/cpu/cpufreq/policy0/*
/sys/devices/system/cpu/cpufreq/policy0/affected_cpus                             0
/sys/devices/system/cpu/cpufreq/policy0/amd_pstate_highest_perf                   231
/sys/devices/system/cpu/cpufreq/policy0/amd_pstate_hw_prefcore                    enabled
/sys/devices/system/cpu/cpufreq/policy0/amd_pstate_lowest_nonlinear_freq          1746000
/sys/devices/system/cpu/cpufreq/policy0/amd_pstate_max_freq                       5274000
/sys/devices/system/cpu/cpufreq/policy0/amd_pstate_prefcore_ranking               231
/sys/devices/system/cpu/cpufreq/policy0/boost                                     1
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq                          5274000
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq                          550000
/sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency                0
/sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences  default performance balance_performance balance_power power
/sys/devices/system/cpu/cpufreq/policy0/energy_performance_preference             balance_performance
/sys/devices/system/cpu/cpufreq/policy0/related_cpus                              0
/sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors               performance powersave
/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq                          1746000
/sys/devices/system/cpu/cpufreq/policy0/scaling_driver                            amd-pstate-epp
/sys/devices/system/cpu/cpufreq/policy0/scaling_governor                          powersave
/sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq                          5274000
/sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq                          1746000
/sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed                          <unsupported>

$ grep -w cppc /proc/cpuinfo
<empty>
```

Thanks,
-- 
Ivan Shapovalov / intelfx /

Re: [PATCH v3 00/11] Adjustments for preferred core detection

[Mario Limonciello]

On 10/16/2024 17:03, Ivan Shapovalov wrote:
> Hi,
> 
> On my desktop Zen 3 (Vermeer) system applying this series yields a new
> warning message on each boot:
> 
>> Oct 16 06:20:41 kernel: Could not retrieve highest performance (-19)
> 
> As I see it, this is one of the pr_debug()s newly promoted to warnings.
> Is there anything I can provide to help fix this?
> 

Open up a kernel Bugzilla and attach a full dmesg and all details.  You 
can CC me directly to it and I'll look into it.

Also ideally; can you please check 6.12-rc3.

> Just for completeness:
> 
> ```
> $ cat-files /sys/devices/system/cpu/cpufreq/policy0/*
> /sys/devices/system/cpu/cpufreq/policy0/affected_cpus                             0
> /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_highest_perf                   231
> /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_hw_prefcore                    enabled
> /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_lowest_nonlinear_freq          1746000
> /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_max_freq                       5274000
> /sys/devices/system/cpu/cpufreq/policy0/amd_pstate_prefcore_ranking               231
> /sys/devices/system/cpu/cpufreq/policy0/boost                                     1
> /sys/devices/system/cpu/cpufreq/policy0/cpuinfo_max_freq                          5274000
> /sys/devices/system/cpu/cpufreq/policy0/cpuinfo_min_freq                          550000
> /sys/devices/system/cpu/cpufreq/policy0/cpuinfo_transition_latency                0
> /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences  default performance balance_performance balance_power power
> /sys/devices/system/cpu/cpufreq/policy0/energy_performance_preference             balance_performance
> /sys/devices/system/cpu/cpufreq/policy0/related_cpus                              0
> /sys/devices/system/cpu/cpufreq/policy0/scaling_available_governors               performance powersave
> /sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq                          1746000
> /sys/devices/system/cpu/cpufreq/policy0/scaling_driver                            amd-pstate-epp
> /sys/devices/system/cpu/cpufreq/policy0/scaling_governor                          powersave
> /sys/devices/system/cpu/cpufreq/policy0/scaling_max_freq                          5274000
> /sys/devices/system/cpu/cpufreq/policy0/scaling_min_freq                          1746000
> /sys/devices/system/cpu/cpufreq/policy0/scaling_setspeed                          <unsupported>
> 
> $ grep -w cppc /proc/cpuinfo
> <empty>
> ```
> 
> Thanks,

Re: [PATCH v3 00/11] Adjustments for preferred core detection

[Ivan Shapovalov]

On 2024-10-16 at 17:06 -0500, Mario Limonciello wrote:
> On 10/16/2024 17:03, Ivan Shapovalov wrote:
> > Hi,
> > 
> > On my desktop Zen 3 (Vermeer) system applying this series yields a new
> > warning message on each boot:
> > 
> > > Oct 16 06:20:41 kernel: Could not retrieve highest performance (-19)
> > 
> > As I see it, this is one of the pr_debug()s newly promoted to warnings.
> > Is there anything I can provide to help fix this?
> > 
> 
> Open up a kernel Bugzilla and attach a full dmesg and all details.  You 
> can CC me directly to it and I'll look into it.
> 
> Also ideally; can you please check 6.12-rc3.
> 

Alright, I'll do that once I build and test the -rc.

Besides dmesg+config+cpuinfo, are there any other details that you
would like to see there?

Thanks,
> 
-- 
Ivan Shapovalov / intelfx /

Re: [PATCH v3 00/11] Adjustments for preferred core detection

[Mario Limonciello]

On 10/16/24 17:19, Ivan Shapovalov wrote:
> On 2024-10-16 at 17:06 -0500, Mario Limonciello wrote:
>> On 10/16/2024 17:03, Ivan Shapovalov wrote:
>>> Hi,
>>>
>>> On my desktop Zen 3 (Vermeer) system applying this series yields a new
>>> warning message on each boot:
>>>
>>>> Oct 16 06:20:41 kernel: Could not retrieve highest performance (-19)
>>>
>>> As I see it, this is one of the pr_debug()s newly promoted to warnings.
>>> Is there anything I can provide to help fix this?
>>>
>>
>> Open up a kernel Bugzilla and attach a full dmesg and all details.  You
>> can CC me directly to it and I'll look into it.
>>
>> Also ideally; can you please check 6.12-rc3.
>>
> 
> Alright, I'll do that once I build and test the -rc.
> 
> Besides dmesg+config+cpuinfo, are there any other details that you
> would like to see there?
> 
> Thanks,
>>

That's fine for now.  Depending on what we find we might want to look at 
an acpidump too.