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AMD Pstate Fixes And Enhancements

PATCH Superseded Perry Yuan 2 participants 12 messages Feb 2, 2024

Subsystems (5)
x86 ACPI CPU frequency scaling framework AMD pstate driver +1 more subsystems

v2 of 12 Superseded Latest is v12 →

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Perry Yuan

author reviewer
#0 lore raw

v2 cover AMD Pstate Fixes And Enhancements

The patch series adds some fixes and enhancements to the AMD pstate driver.
It enables CPPC v2 for certain processors in the family 17H, as requested
by TR40 processor users who expect improved performance and lower system temperature.

Additionally, it fixes the initialization of nominal_freq for each cpudata
and changes latency and delay values to be read from platform firmware firstly
for more accurate timing.

A new quirk is also added for legacy processors that lack CPPC capabilities which caused the pstate driver to fail loading.

I would greatly appreciate any feedbacks.

Thank you!

Changes from v1:
* pick up the RB flags from Mario
* address review comment of patch #6 for amd_get_nominal_freq()
* rebased the series to linux-pm/bleeding-edge v6.8.0-rc2
* update debug log for patch #5 as Mario suggested.
* fix some typos and format problems
* tested on 7950X platform

V1: https://lore.kernel.org/lkml/[email protected]/

Perry Yuan (6):
ACPI: CPPC: enable AMD CPPC V2 support for family 17h processors cpufreq:amd-pstate: fix the nominal freq value set cpufreq:amd-pstate: initialize nominal_freq of each cpudata cpufreq:amd-pstate: get pstate transition delay and latency value from
ACPI tables
cppc_acpi: print error message if CPPC is unsupported cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

 arch/x86/kernel/acpi/cppc.c  |   2 +-
 drivers/acpi/cppc_acpi.c     |   4 +-
 drivers/cpufreq/amd-pstate.c | 108 +++++++++++++++++++++++++++++------
 include/linux/amd-pstate.h   |   6 ++
 4 files changed, 101 insertions(+), 19 deletions(-)
Signature · 1 line
2.34.1
author reviewer
#1 lore raw

PATCH v2 1/6 ACPI: CPPC: enable AMD CPPC V2 support for family 17h processors

As there are some AMD processors which only support CPPC V2 firmware and BIOS implementation, the amd_pstate driver will be failed to load when system booting with below kernel warning message:

[    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled

To make the amd_pstate driver can be loaded on those TR40 processors, it needs to match x86_model from 0x30 to 0x7F for family 17H. With the change, the system can load amd_pstate driver as expected.

Reviewed-by Mario Limonciello <[email protected]>
Reported-by Gino Badouri <[email protected]>
Closes https://bugzilla.kernel.org/show_bug.cgi?id=218171
Fixes fbd74d1689 ("ACPI: CPPC: Fix enabling CPPC on AMD systems with shared memory")
Signed-off-by Perry Yuan <[email protected]>
---
 arch/x86/kernel/acpi/cppc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/kernel/acpi/cppc.c +1 -1
index 8d8752b44f11..ff8f25faca3d 100644
@@ -20,7 +20,7 @@ bool cpc_supported_by_cpu(void)
 		    (boot_cpu_data.x86_model >= 0x20 && boot_cpu_data.x86_model <= 0x2f)))
 			return true;
 		else if (boot_cpu_data.x86 == 0x17 &&
-			 boot_cpu_data.x86_model >= 0x70 && boot_cpu_data.x86_model <= 0x7f)
+			 boot_cpu_data.x86_model >= 0x30 && boot_cpu_data.x86_model <= 0x7f)
 			return true;
 		return boot_cpu_has(X86_FEATURE_CPPC);
 	}
Signature · 1 line
2.34.1
author reviewer
#2 lore raw

PATCH v2 2/6 cpufreq:amd-pstate: fix the nominal freq value set

In reply to Perry Yuan

Address an untested error where the nominal_freq was returned in KHz instead of the correct MHz units, this oversight led to a wrong nominal_freq set and resued, it will cause the max frequency of core to be initialized with a wrong frequency value.

Cc [email protected]
Fixes ec437d71db7 ("cpufreq: amd-pstate: Introduce a new AMD P-State driver to support future processors")
Reviewed-by Mario Limonciello <[email protected]>
Signed-off-by Perry Yuan <[email protected]>
---
 drivers/cpufreq/amd-pstate.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
drivers/cpufreq/amd-pstate.c +1 -2
index 08e112444c27..ac7faa98a450 100644
@@ -640,8 +640,7 @@ static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
 	if (ret)
 		return ret;
 
-	/* Switch to khz */
-	return cppc_perf.nominal_freq * 1000;
+	return cppc_perf.nominal_freq;
 }
 
 static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
Signature · 1 line
2.34.1
author reviewer
#3 lore raw

PATCH v2 3/6 cpufreq:amd-pstate: initialize nominal_freq of each cpudata

In reply to Perry Yuan

Optimizes the process of retrieving the nominal frequency by utilizing 'cpudata->nominal_freq' instead of repeatedly accessing the cppc_acpi interface.

To enhance efficiency and reduce the CPU load, shifted to using 'cpudata->nominal_freq'. It allows for the nominal frequency to be accessed directly from the cached data in 'cpudata' of each CPU.
It will also slightly reduce the frequency change latency while using pstate driver passive mode.

Reviewed-by Mario Limonciello <[email protected]>
Signed-off-by Perry Yuan <[email protected]>
---
 drivers/cpufreq/amd-pstate.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)
drivers/cpufreq/amd-pstate.c +12 -12
index ac7faa98a450..ea8681ea3bad 100644
@@ -619,7 +619,7 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
 	if (ret)
 		return ret;
 
-	nominal_freq = cppc_perf.nominal_freq;
+	nominal_freq = READ_ONCE(cpudata->nominal_freq);
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	max_perf = READ_ONCE(cpudata->highest_perf);
 

@@ -654,7 +654,7 @@ static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
 	if (ret)
 		return ret;
 
-	nominal_freq = cppc_perf.nominal_freq;
+	nominal_freq = READ_ONCE(cpudata->nominal_freq);
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 
 	lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;

@@ -848,13 +848,14 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 		goto free_cpudata1;
 
 	min_freq = amd_get_min_freq(cpudata);
-	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
+	cpudata->nominal_freq = nominal_freq;
+	max_freq = amd_get_max_freq(cpudata);
 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
 
-	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
-		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
-			min_freq, max_freq);
+	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) {
+		dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n",
+			min_freq, max_freq, nominal_freq);
 		ret = -EINVAL;
 		goto free_cpudata1;
 	}

@@ -893,7 +894,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	cpudata->min_freq = min_freq;
 	cpudata->max_limit_freq = max_freq;
 	cpudata->min_limit_freq = min_freq;
-	cpudata->nominal_freq = nominal_freq;
 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
 
 	policy->driver_data = cpudata;

@@ -1310,12 +1310,13 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 		goto free_cpudata1;
 
 	min_freq = amd_get_min_freq(cpudata);
-	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
+	cpudata->nominal_freq = nominal_freq;
+	max_freq = amd_get_max_freq(cpudata);
 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
-	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
-		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
-				min_freq, max_freq);
+	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq || nominal_freq == 0) {
+		dev_err(dev, "min_freq(%d) or max_freq(%d) or nominal_freq(%d) is incorrect\n",
+				min_freq, max_freq, nominal_freq);
 		ret = -EINVAL;
 		goto free_cpudata1;
 	}

@@ -1328,7 +1329,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	/* Initial processor data capability frequencies */
 	cpudata->max_freq = max_freq;
 	cpudata->min_freq = min_freq;
-	cpudata->nominal_freq = nominal_freq;
 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
 
 	policy->driver_data = cpudata;
Signature · 1 line
2.34.1
author reviewer
#4 lore raw

PATCH v2 4/6 cpufreq:amd-pstate: get pstate transition delay and latency value from ACPI tables

In reply to Perry Yuan

make pstate driver initially retrieve the P-state transition delay and latency values from the BIOS ACPI tables which has more reasonable delay and latency values according to the platform design and requirements.

Previously there values were hardcoded at specific value which may have conflicted with platform and it might not reflect the most accurate or optimized setting for the processor.

[054h 0084   8]                Preserve Mask : FFFFFFFF00000000
[05Ch 0092   8]                   Write Mask : 0000000000000001
[064h 0100   4]              Command Latency : 00000FA0
[068h 0104   4]          Maximum Access Rate : 0000EA60
[06Ch 0108   2]      Minimum Turnaround Time : 0000
Reviewed-by Mario Limonciello <[email protected]>
Signed-off-by Perry Yuan <[email protected]>
---
 drivers/cpufreq/amd-pstate.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)
drivers/cpufreq/amd-pstate.c +32 -2
index ea8681ea3bad..77effc3caf6c 100644
@@ -820,6 +820,36 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	mutex_unlock(&amd_pstate_driver_lock);
 }
 
+/**
+ * Get pstate transition delay time from ACPI tables that firmware set
+ * instead of using hardcode value directly.
+ */
+static u32 amd_pstate_get_transition_delay_us(unsigned int cpu)
+{
+	u32 transition_delay_ns;
+
+	transition_delay_ns = cppc_get_transition_latency(cpu);
+	if (transition_delay_ns == CPUFREQ_ETERNAL)
+		return AMD_PSTATE_TRANSITION_DELAY;
+
+	return transition_delay_ns / NSEC_PER_USEC;
+}
+
+/**
+ * Get pstate transition latency value from ACPI tables that firmware set
+ * instead of using hardcode value directly.
+ */
+static u32 amd_pstate_get_transition_latency(unsigned int cpu)
+{
+	u32 transition_latency;
+
+	transition_latency = cppc_get_transition_latency(cpu);
+	if (transition_latency  == CPUFREQ_ETERNAL)
+		return AMD_PSTATE_TRANSITION_LATENCY;
+
+	return transition_latency;
+}
+
 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 {
 	int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;

@@ -860,8 +890,8 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 		goto free_cpudata1;
 	}
 
-	policy->cpuinfo.transition_latency = AMD_PSTATE_TRANSITION_LATENCY;
-	policy->transition_delay_us = AMD_PSTATE_TRANSITION_DELAY;
+	policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu);
+	policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu);
 
 	policy->min = min_freq;
 	policy->max = max_freq;
Signature · 1 line
2.34.1
author reviewer
#5 lore raw

PATCH v2 5/6 cppc_acpi: print error message if CPPC is unsupported

In reply to Perry Yuan

to be more clear what is wrong with CPPC when pstate driver failed to load which has dependency on the CPPC capabilities.

Add one more debug message to notify user if CPPC is not supported by the CPU, then it will be easy to find out what need to fix for pstate driver loading issue.

[    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled

Above message is not clear enough to verify whether CPPC is not supported.

Signed-off-by Perry Yuan <[email protected]>
---
 drivers/acpi/cppc_acpi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
drivers/acpi/cppc_acpi.c +3 -1
index a50e70abdf19..e23a84f4a50a 100644
@@ -679,8 +679,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 
 	if (!osc_sb_cppc2_support_acked) {
 		pr_debug("CPPC v2 _OSC not acked\n");
-		if (!cpc_supported_by_cpu())
+		if (!cpc_supported_by_cpu()) {
+			pr_debug("CPPC is not supported by the CPU\n");
 			return -ENODEV;
+		}
 	}
 
 	/* Parse the ACPI _CPC table for this CPU. */
Signature · 1 line
2.34.1
author reviewer
#7 lore raw

PATCH v2 6/6 cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

In reply to Perry Yuan

Add quirk table to get CPPC capabilities issue fixed by providing correct perf or frequency values while driver loading.

If CPPC capabilities are not defined in the ACPI tables or wrongly defined by platform firmware, it needs to use quick to get those issues fixed with correct workaround values to make pstate driver can be loaded even though there are CPPC capabilities errors.

Signed-off-by Perry Yuan <[email protected]>
---
 drivers/cpufreq/amd-pstate.c | 49 ++++++++++++++++++++++++++++++++++--
 include/linux/amd-pstate.h   |  6 +++++
 2 files changed, 53 insertions(+), 2 deletions(-)
drivers/cpufreq/amd-pstate.c +47 -2
index 77effc3caf6c..4d426516abb9 100644
@@ -67,6 +67,7 @@ static struct cpufreq_driver amd_pstate_epp_driver;
 static int cppc_state = AMD_PSTATE_UNDEFINED;
 static bool cppc_enabled;
 static bool amd_pstate_prefcore = true;
+static struct quirk_entry *quirks;
 
 /*
  * AMD Energy Preference Performance (EPP)

@@ -111,6 +112,33 @@ static unsigned int epp_values[] = {
 
 typedef int (*cppc_mode_transition_fn)(int);
 
+static struct quirk_entry quirk_amd_7k62 = {
+	.nominal_freq = 2600,
+	.lowest_freq = 550,
+};
+
+static int __init dmi_matched(const struct dmi_system_id *dmi)
+{
+	quirks = dmi->driver_data;
+	pr_info("hardware type %s found\n", dmi->ident);
+
+	return 1;
+}
+
+static const struct dmi_system_id amd_pstate_quirks_table[] __initconst = {
+	{
+		.callback = dmi_matched,
+		.ident = "AMD EPYC 7K62",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_VERSION, "C1"),
+			DMI_MATCH(DMI_PRODUCT_SERIAL, "FX19911000028"),
+		},
+		.driver_data = &quirk_amd_7k62,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table);
+
 static inline int get_mode_idx_from_str(const char *str, size_t size)
 {
 	int i;

@@ -600,13 +628,19 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
 static int amd_get_min_freq(struct amd_cpudata *cpudata)
 {
 	struct cppc_perf_caps cppc_perf;
+	u32 lowest_freq;
 
 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
 	if (ret)
 		return ret;
 
+	if (quirks && quirks->lowest_freq)
+		lowest_freq = quirks->lowest_freq;
+	else
+		lowest_freq = cppc_perf.lowest_freq;
+
 	/* Switch to khz */
-	return cppc_perf.lowest_freq * 1000;
+	return lowest_freq * 1000;
 }
 
 static int amd_get_max_freq(struct amd_cpudata *cpudata)

@@ -635,12 +669,18 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
 static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
 {
 	struct cppc_perf_caps cppc_perf;
+	u32 nominal_freq;
 
 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
 	if (ret)
 		return ret;
 
-	return cppc_perf.nominal_freq;
+	if (quirks && quirks->nominal_freq)
+		nominal_freq = quirks->nominal_freq;
+	else
+		nominal_freq = cppc_perf.nominal_freq;
+
+	return nominal_freq;
 }
 
 static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)

@@ -1672,6 +1712,11 @@ static int __init amd_pstate_init(void)
 	if (cpufreq_get_current_driver())
 		return -EEXIST;
 
+	quirks = NULL;
+
+	/* check if this machine need CPPC quirks */
+	dmi_check_system(amd_pstate_quirks_table);
+
 	switch (cppc_state) {
 	case AMD_PSTATE_UNDEFINED:
 		/* Disable on the following configs by default:
include/linux/amd-pstate.h +6 -0
index d21838835abd..7b2cbb892fd9 100644
@@ -124,4 +124,10 @@ static const char * const amd_pstate_mode_string[] = {
 	[AMD_PSTATE_GUIDED]      = "guided",
 	NULL,
 };
+
+struct quirk_entry {
+	u32 nominal_freq;
+	u32 lowest_freq;
+};
+
 #endif /* _LINUX_AMD_PSTATE_H */
Signature · 1 line
2.34.1
maintainer
#8 lore raw

Re: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

Quoted 40 lines · Perry Yuan

Add quirk table to get CPPC capabilities issue fixed by providing correct perf or frequency values while driver loading.

If CPPC capabilities are not defined in the ACPI tables or wrongly defined by platform firmware, it needs to use quick to get those issues fixed with correct workaround values to make pstate driver can be loaded even though there are CPPC capabilities errors.

Signed-off-by Perry Yuan <[email protected]>
---
  drivers/cpufreq/amd-pstate.c | 49 ++++++++++++++++++++++++++++++++++--
  include/linux/amd-pstate.h   |  6 +++++
  2 files changed, 53 insertions(+), 2 deletions(-)
drivers/cpufreq/amd-pstate.c +11 -0
index 77effc3caf6c..4d426516abb9 100644
@@ -67,6 +67,7 @@ static struct cpufreq_driver amd_pstate_epp_driver;
  static int cppc_state = AMD_PSTATE_UNDEFINED;
  static bool cppc_enabled;
  static bool amd_pstate_prefcore = true;
+static struct quirk_entry *quirks;
 
  /*
   * AMD Energy Preference Performance (EPP)

@@ -111,6 +112,33 @@ static unsigned int epp_values[] = {
 
  typedef int (*cppc_mode_transition_fn)(int);
 
+static struct quirk_entry quirk_amd_7k62 = {
+	.nominal_freq = 2600,
+	.lowest_freq = 550,
+};
+
+static int __init dmi_matched(const struct dmi_system_id *dmi)
+{
+	quirks = dmi->driver_data;
+	pr_info("hardware type %s found\n", dmi->ident);
+

drivers/cpufreq/amd-pstate.c static unsigned int epp_values[] = { · line 134

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10 -0
+	return 1;
+}
+
+static const struct dmi_system_id amd_pstate_quirks_table[] __initconst = {
+	{
+		.callback = dmi_matched,
+		.ident = "AMD EPYC 7K62",
+		.matches = {
+			DMI_MATCH(DMI_PRODUCT_VERSION, "C1"),
+			DMI_MATCH(DMI_PRODUCT_SERIAL, "FX19911000028")

I saw your response to v1, but really this is too narrow for upstream. It's literally applying to a SINGLE system.

I feel the rest of the patch is fine, but we shouldn't be adding single system quirks.

Quoted 78 lines
drivers/cpufreq/amd-pstate.c +26 -2
+		},
+		.driver_data = &quirk_amd_7k62,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table);
+
  static inline int get_mode_idx_from_str(const char *str, size_t size)
  {
  	int i;

@@ -600,13 +628,19 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
  static int amd_get_min_freq(struct amd_cpudata *cpudata)
  {
  	struct cppc_perf_caps cppc_perf;
+	u32 lowest_freq;
 
  	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
  	if (ret)
  		return ret;
 
+	if (quirks && quirks->lowest_freq)
+		lowest_freq = quirks->lowest_freq;
+	else
+		lowest_freq = cppc_perf.lowest_freq;
+
  	/* Switch to khz */
-	return cppc_perf.lowest_freq * 1000;
+	return lowest_freq * 1000;
  }
 
  static int amd_get_max_freq(struct amd_cpudata *cpudata)

@@ -635,12 +669,18 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
  static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
  {
  	struct cppc_perf_caps cppc_perf;
+	u32 nominal_freq;
 
  	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
  	if (ret)
  		return ret;
 
-	return cppc_perf.nominal_freq;
+	if (quirks && quirks->nominal_freq)
+		nominal_freq = quirks->nominal_freq;
+	else
+		nominal_freq = cppc_perf.nominal_freq;
+
+	return nominal_freq;
  }
 
  static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)

@@ -1672,6 +1712,11 @@ static int __init amd_pstate_init(void)
  	if (cpufreq_get_current_driver())
  		return -EEXIST;
 
+	quirks = NULL;
+
+	/* check if this machine need CPPC quirks */
+	dmi_check_system(amd_pstate_quirks_table);
+
  	switch (cppc_state) {
  	case AMD_PSTATE_UNDEFINED:
  		/* Disable on the following configs by default:
include/linux/amd-pstate.h +6 -0
index d21838835abd..7b2cbb892fd9 100644
@@ -124,4 +124,10 @@ static const char * const amd_pstate_mode_string[] = {
  	[AMD_PSTATE_GUIDED]      = "guided",
  	NULL,
  };
+
+struct quirk_entry {
+	u32 nominal_freq;
+	u32 lowest_freq;
+};
+
  #endif /* _LINUX_AMD_PSTATE_H */
maintainer Reviewed-by on v2 5/6
#6 lore raw

Re: [PATCH v2 5/6] cppc_acpi: print error message if CPPC is unsupported

In reply to Perry Yuan
Quoted 7 lines · Perry Yuan

to be more clear what is wrong with CPPC when pstate driver failed to load which has dependency on the CPPC capabilities.

Add one more debug message to notify user if CPPC is not supported by the CPU, then it will be easy to find out what need to fix for pstate driver loading issue.

Quoted 5 lines
[    0.477523] amd_pstate: the _CPC object is not present in SBIOS or ACPI disabled

Above message is not clear enough to verify whether CPPC is not supported.

Signed-off-by Perry Yuan <[email protected]>
Reviewed-by Mario Limonciello <[email protected]>
Quoted 20 lines
---
  drivers/acpi/cppc_acpi.c | 4 +++-
  1 file changed, 3 insertions(+), 1 deletion(-)
drivers/acpi/cppc_acpi.c +3 -1
index a50e70abdf19..e23a84f4a50a 100644
@@ -679,8 +679,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 
  	if (!osc_sb_cppc2_support_acked) {
  		pr_debug("CPPC v2 _OSC not acked\n");
-		if (!cpc_supported_by_cpu())
+		if (!cpc_supported_by_cpu()) {
+			pr_debug("CPPC is not supported by the CPU\n");
  			return -ENODEV;
+		}
  	}
 
  	/* Parse the ACPI _CPC table for this CPU. */
author reviewer
#9 lore raw

RE: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

In reply to Mario Limonciello

[AMD Official Use Only - General]

Hi Mario,

Quoted 66 lines

-----Original Message-----
From: Limonciello, Mario <[email protected]>
Sent: Friday, February 2, 2024 11:17 PM
To: Yuan, Perry <[email protected]>; [email protected]; [email protected]; Huang, Ray <[email protected]>; Shenoy, Gautham Ranjal <[email protected]>; Petkov, Borislav <[email protected]>
Cc: Deucher, Alexander <[email protected]>; Huang, Shimmer <[email protected]>; Du, Xiaojian <[email protected]>; Meng, Li (Jassmine) <[email protected]>; [email protected]; linux- [email protected]
Subject: Re: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

Quoted 11 lines · Perry Yuan

Add quirk table to get CPPC capabilities issue fixed by providing correct perf or frequency values while driver loading.

If CPPC capabilities are not defined in the ACPI tables or wrongly defined by platform firmware, it needs to use quick to get those issues fixed with correct workaround values to make pstate driver can be loaded even though there are CPPC capabilities errors.

Signed-off-by Perry Yuan <[email protected]>
---
  drivers/cpufreq/amd-pstate.c | 49

++++++++++++++++++++++++++++++++++--

Quoted 22 lines
  include/linux/amd-pstate.h   |  6 +++++
  2 files changed, 53 insertions(+), 2 deletions(-)
(quoted diff) +0 -0

b/drivers/cpufreq/amd-pstate.c index 77effc3caf6c..4d426516abb9 100644

drivers/cpufreq/amd-pstate.c +1 -0
@@ -67,6 +67,7 @@ static struct cpufreq_driver amd_pstate_epp_driver;
  static int cppc_state = AMD_PSTATE_UNDEFINED;
  static bool cppc_enabled;
  static bool amd_pstate_prefcore = true;
+static struct quirk_entry *quirks;
 
  /*
   * AMD Energy Preference Performance (EPP) @@ -111,6 +112,33 @@

static unsigned int epp_values[] = {

  typedef int (*cppc_mode_transition_fn)(int);
drivers/cpufreq/amd-pstate.c +3 -0
+static struct quirk_entry quirk_amd_7k62 = {
+   .nominal_freq = 2600,
+   .lowest_freq = 550,

drivers/cpufreq/amd-pstate.c static unsigned int epp_values[] = {

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10 -0
+};
+
+static int __init dmi_matched(const struct dmi_system_id *dmi) {
+   quirks = dmi->driver_data;
+   pr_info("hardware type %s found\n", dmi->ident);
+
+   return 1;
+}
+
+static const struct dmi_system_id amd_pstate_quirks_table[] __initconst

= {

drivers/cpufreq/amd-pstate.c static unsigned int epp_values[] = {

Quoted 6 lines
drivers/cpufreq/amd-pstate.c +6 -0
+   {
+           .callback = dmi_matched,
+           .ident = "AMD EPYC 7K62",
+           .matches = {
+                   DMI_MATCH(DMI_PRODUCT_VERSION, "C1"),
+                   DMI_MATCH(DMI_PRODUCT_SERIAL,
Quoted 7 lines

"FX19911000028")

I saw your response to v1, but really this is too narrow for upstream. It's literally applying to a SINGLE system.

I feel the rest of the patch is fine, but we shouldn't be adding single system quirks.

How about change to match the BIOS version ?
Actually, the issue should be impacting all the systems which have the same broken BIOS.

Perry.

Quoted 81 lines

drivers/cpufreq/amd-pstate.c static void amd_pstate_adjust_perf(unsigned int

Quoted 12 lines
drivers/cpufreq/amd-pstate.c +7 -0
+           },
+           .driver_data = &quirk_amd_7k62,
+   },
+   {}
+};
+MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table);
+
  static inline int get_mode_idx_from_str(const char *str, size_t size)
  {
    int i;

@@ -600,13 +628,19 @@ static void amd_pstate_adjust_perf(unsigned int

cpu,

include/linux/amd-pstate.h static const char * const

Quoted 57 lines
drivers/cpufreq/amd-pstate.c +15 -2
  static int amd_get_min_freq(struct amd_cpudata *cpudata)
  {
    struct cppc_perf_caps cppc_perf;
+   u32 lowest_freq;
 
    int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
    if (ret)
            return ret;
 
+   if (quirks && quirks->lowest_freq)
+           lowest_freq = quirks->lowest_freq;
+   else
+           lowest_freq = cppc_perf.lowest_freq;
+
    /* Switch to khz */
-   return cppc_perf.lowest_freq * 1000;
+   return lowest_freq * 1000;
  }
 
  static int amd_get_max_freq(struct amd_cpudata *cpudata) @@ -635,12
+669,18 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
  static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
  {
    struct cppc_perf_caps cppc_perf;
+   u32 nominal_freq;
 
    int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
    if (ret)
            return ret;
 
-   return cppc_perf.nominal_freq;
+   if (quirks && quirks->nominal_freq)
+           nominal_freq = quirks->nominal_freq;
+   else
+           nominal_freq = cppc_perf.nominal_freq;
+
+   return nominal_freq;
  }
 
  static int amd_get_lowest_nonlinear_freq(struct amd_cpudata

*cpudata) @@ -1672,6 +1712,11 @@ static int __init amd_pstate_init(void)

    if (cpufreq_get_current_driver())
            return -EEXIST;
drivers/cpufreq/amd-pstate.c +5 -0
+   quirks = NULL;
+
+   /* check if this machine need CPPC quirks */
+   dmi_check_system(amd_pstate_quirks_table);
+
    switch (cppc_state) {
    case AMD_PSTATE_UNDEFINED:
            /* Disable on the following configs by default:
include/linux/amd-pstate.h +0 -0
index d21838835abd..7b2cbb892fd9 100644
@@ -124,4 +124,10 @@ static const char * const

amd_pstate_mode_string[] = {

Quoted 10 lines
include/linux/amd-pstate.h +6 -0
    [AMD_PSTATE_GUIDED]      = "guided",
    NULL,
  };
+
+struct quirk_entry {
+   u32 nominal_freq;
+   u32 lowest_freq;
+};
+
  #endif /* _LINUX_AMD_PSTATE_H */
maintainer
#10 lore raw

Re: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

Quoted 72 lines · Perry

[AMD Official Use Only - General]

Hi Mario,

Quoted 68 lines

-----Original Message-----
From: Limonciello, Mario <[email protected]>
Sent: Friday, February 2, 2024 11:17 PM
To: Yuan, Perry <[email protected]>; [email protected]; [email protected]; Huang, Ray <[email protected]>; Shenoy, Gautham Ranjal <[email protected]>; Petkov, Borislav <[email protected]>
Cc: Deucher, Alexander <[email protected]>; Huang, Shimmer <[email protected]>; Du, Xiaojian <[email protected]>; Meng, Li (Jassmine) <[email protected]>; [email protected]; linux- [email protected]
Subject: Re: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

Quoted 11 lines · Perry Yuan

Add quirk table to get CPPC capabilities issue fixed by providing correct perf or frequency values while driver loading.

If CPPC capabilities are not defined in the ACPI tables or wrongly defined by platform firmware, it needs to use quick to get those issues fixed with correct workaround values to make pstate driver can be loaded even though there are CPPC capabilities errors.

Signed-off-by Perry Yuan <[email protected]>
---
   drivers/cpufreq/amd-pstate.c | 49

++++++++++++++++++++++++++++++++++--

Quoted 22 lines
   include/linux/amd-pstate.h   |  6 +++++
   2 files changed, 53 insertions(+), 2 deletions(-)
(quoted diff) +0 -0

b/drivers/cpufreq/amd-pstate.c index 77effc3caf6c..4d426516abb9 100644

drivers/cpufreq/amd-pstate.c +1 -0
@@ -67,6 +67,7 @@ static struct cpufreq_driver amd_pstate_epp_driver;
   static int cppc_state = AMD_PSTATE_UNDEFINED;
   static bool cppc_enabled;
   static bool amd_pstate_prefcore = true;
+static struct quirk_entry *quirks;
 
   /*
    * AMD Energy Preference Performance (EPP) @@ -111,6 +112,33 @@

static unsigned int epp_values[] = {

   typedef int (*cppc_mode_transition_fn)(int);
drivers/cpufreq/amd-pstate.c +3 -0
+static struct quirk_entry quirk_amd_7k62 = {
+   .nominal_freq = 2600,
+   .lowest_freq = 550,

drivers/cpufreq/amd-pstate.c static unsigned int epp_values[] = {

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10 -0
+};
+
+static int __init dmi_matched(const struct dmi_system_id *dmi) {
+   quirks = dmi->driver_data;
+   pr_info("hardware type %s found\n", dmi->ident);
+
+   return 1;
+}
+
+static const struct dmi_system_id amd_pstate_quirks_table[] __initconst

= {

drivers/cpufreq/amd-pstate.c static unsigned int epp_values[] = {

Quoted 6 lines
drivers/cpufreq/amd-pstate.c +6 -0
+   {
+           .callback = dmi_matched,
+           .ident = "AMD EPYC 7K62",
+           .matches = {
+                   DMI_MATCH(DMI_PRODUCT_VERSION, "C1"),
+                   DMI_MATCH(DMI_PRODUCT_SERIAL,

"FX19911000028")

Quoted 9 lines
Quoted 5 lines

I saw your response to v1, but really this is too narrow for upstream. It's literally applying to a SINGLE system.

I feel the rest of the patch is fine, but we shouldn't be adding single system quirks.

How about change to match the BIOS version ?
Actually, the issue should be impacting all the systems which have the same broken BIOS.

Yeah it does sound like a BIOS defect; so this is a reasonable alternative. Just make sure that you only apply it to the necessary systems with this change.

Quoted 85 lines

Perry.

Quoted 81 lines

drivers/cpufreq/amd-pstate.c static void amd_pstate_adjust_perf(unsigned int

Quoted 12 lines
drivers/cpufreq/amd-pstate.c +7 -0
+           },
+           .driver_data = &quirk_amd_7k62,
+   },
+   {}
+};
+MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table);
+
   static inline int get_mode_idx_from_str(const char *str, size_t size)
   {
     int i;

@@ -600,13 +628,19 @@ static void amd_pstate_adjust_perf(unsigned int

cpu,

include/linux/amd-pstate.h static const char * const

Quoted 57 lines
drivers/cpufreq/amd-pstate.c +15 -2
   static int amd_get_min_freq(struct amd_cpudata *cpudata)
   {
     struct cppc_perf_caps cppc_perf;
+   u32 lowest_freq;
 
     int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
     if (ret)
             return ret;
 
+   if (quirks && quirks->lowest_freq)
+           lowest_freq = quirks->lowest_freq;
+   else
+           lowest_freq = cppc_perf.lowest_freq;
+
     /* Switch to khz */
-   return cppc_perf.lowest_freq * 1000;
+   return lowest_freq * 1000;
   }
 
   static int amd_get_max_freq(struct amd_cpudata *cpudata) @@ -635,12
+669,18 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
   static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
   {
     struct cppc_perf_caps cppc_perf;
+   u32 nominal_freq;
 
     int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
     if (ret)
             return ret;
 
-   return cppc_perf.nominal_freq;
+   if (quirks && quirks->nominal_freq)
+           nominal_freq = quirks->nominal_freq;
+   else
+           nominal_freq = cppc_perf.nominal_freq;
+
+   return nominal_freq;
   }
 
   static int amd_get_lowest_nonlinear_freq(struct amd_cpudata

*cpudata) @@ -1672,6 +1712,11 @@ static int __init amd_pstate_init(void)

     if (cpufreq_get_current_driver())
             return -EEXIST;
drivers/cpufreq/amd-pstate.c +5 -0
+   quirks = NULL;
+
+   /* check if this machine need CPPC quirks */
+   dmi_check_system(amd_pstate_quirks_table);
+
     switch (cppc_state) {
     case AMD_PSTATE_UNDEFINED:
             /* Disable on the following configs by default:
include/linux/amd-pstate.h +0 -0
index d21838835abd..7b2cbb892fd9 100644
@@ -124,4 +124,10 @@ static const char * const

amd_pstate_mode_string[] = {

Quoted 10 lines
include/linux/amd-pstate.h +6 -0
     [AMD_PSTATE_GUIDED]      = "guided",
     NULL,
   };
+
+struct quirk_entry {
+   u32 nominal_freq;
+   u32 lowest_freq;
+};
+
   #endif /* _LINUX_AMD_PSTATE_H */
author reviewer
#11 lore raw

RE: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

[AMD Official Use Only - General]

Quoted 98 lines

-----Original Message-----
From: Limonciello, Mario <[email protected]>
Sent: Friday, February 2, 2024 11:55 PM
To: Yuan, Perry <[email protected]>; [email protected]; [email protected]; Huang, Ray <[email protected]>; Shenoy, Gautham Ranjal <[email protected]>; Petkov, Borislav <[email protected]>
Cc: Deucher, Alexander <[email protected]>; Huang, Shimmer <[email protected]>; Du, Xiaojian <[email protected]>; Meng, Li (Jassmine) <[email protected]>; [email protected]; linux- [email protected]
Subject: Re: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

Quoted 12 lines · Perry

[AMD Official Use Only - General]

Hi Mario,

Quoted 8 lines

-----Original Message-----
From: Limonciello, Mario <[email protected]>
Sent: Friday, February 2, 2024 11:17 PM
To: Yuan, Perry <[email protected]>; [email protected]; [email protected]; Huang, Ray <[email protected]>; Shenoy, Gautham Ranjal <[email protected]>; Petkov, Borislav <[email protected]>
Cc: Deucher, Alexander <[email protected]>; Huang,

Shimmer

Quoted 1 line
Quoted 1 line

<[email protected]>; Du, Xiaojian <[email protected]>;

Meng, Li

Quoted 21 lines
Quoted 21 lines

(Jassmine) <[email protected]>; [email protected]; linux- [email protected]
Subject: Re: [PATCH v2 6/6] cpufreq:amd-pstate: add quirk for the pstate CPPC capabilities missing

Quoted 11 lines · Perry Yuan

Add quirk table to get CPPC capabilities issue fixed by providing correct perf or frequency values while driver loading.

If CPPC capabilities are not defined in the ACPI tables or wrongly defined by platform firmware, it needs to use quick to get those issues fixed with correct workaround values to make pstate driver can be loaded even though there are CPPC capabilities errors.

Signed-off-by Perry Yuan <[email protected]>
---
   drivers/cpufreq/amd-pstate.c | 49

++++++++++++++++++++++++++++++++++--

Quoted 3 lines
   include/linux/amd-pstate.h   |  6 +++++
   2 files changed, 53 insertions(+), 2 deletions(-)
Quoted 6 lines
Quoted 6 lines

drivers/cpufreq/amd-pstate.c static struct cpufreq_driver

Quoted 6 lines
(quoted diff) +0 -0

b/drivers/cpufreq/amd-pstate.c index 77effc3caf6c..4d426516abb9 100644

drivers/cpufreq/amd-pstate.c +0 -0
@@ -67,6 +67,7 @@ static struct cpufreq_driver

amd_pstate_epp_driver;

Quoted 40 lines
Quoted 39 lines
Quoted 15 lines
drivers/cpufreq/amd-pstate.c +1 -0
   static int cppc_state = AMD_PSTATE_UNDEFINED;
   static bool cppc_enabled;
   static bool amd_pstate_prefcore = true;
+static struct quirk_entry *quirks;
 
   /*
    * AMD Energy Preference Performance (EPP) @@ -111,6 +112,33 @@

static unsigned int epp_values[] = {

   typedef int (*cppc_mode_transition_fn)(int);
drivers/cpufreq/amd-pstate.c +4 -0
+static struct quirk_entry quirk_amd_7k62 = {
+   .nominal_freq = 2600,
+   .lowest_freq = 550,
+};

drivers/cpufreq/amd-pstate.c static unsigned int epp_values[] = {

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10 -0
+
+static int __init dmi_matched(const struct dmi_system_id *dmi) {
+   quirks = dmi->driver_data;
+   pr_info("hardware type %s found\n", dmi->ident);
+
+   return 1;
+}
+
+static const struct dmi_system_id amd_pstate_quirks_table[]
+__initconst

= {

drivers/cpufreq/amd-pstate.c static unsigned int epp_values[] = {

Quoted 6 lines
drivers/cpufreq/amd-pstate.c +6 -0
+   {
+           .callback = dmi_matched,
+           .ident = "AMD EPYC 7K62",
+           .matches = {
+                   DMI_MATCH(DMI_PRODUCT_VERSION, "C1"),
+                   DMI_MATCH(DMI_PRODUCT_SERIAL,

"FX19911000028")

I saw your response to v1, but really this is too narrow for upstream. It's literally applying to a SINGLE system.

I feel the rest of the patch is fine, but we shouldn't be adding single system quirks.

Quoted 8 lines
Quoted 2 lines

How about change to match the BIOS version ?
Actually, the issue should be impacting all the systems which have the

same broken BIOS.

Quoted 1 line

Yeah it does sound like a BIOS defect; so this is a reasonable alternative. Just make sure that you only apply it to the necessary systems with this change.

Agreed, let me change to match BIOS version in V3. Thanks for the feedback!

Perry.

Quoted 88 lines
Quoted 57 lines

Perry.

Quoted 54 lines
Quoted 12 lines
drivers/cpufreq/amd-pstate.c +7 -0
+           },
+           .driver_data = &quirk_amd_7k62,
+   },
+   {}
+};
+MODULE_DEVICE_TABLE(dmi, amd_pstate_quirks_table);
+
   static inline int get_mode_idx_from_str(const char *str, size_t size)
   {
     int i;

@@ -600,13 +628,19 @@ static void amd_pstate_adjust_perf(unsigned
Quoted 1 line

int

cpu,

Quoted 40 lines
   static int amd_get_min_freq(struct amd_cpudata *cpudata)
   {
     struct cppc_perf_caps cppc_perf;
drivers/cpufreq/amd-pstate.c +15 -3
+   u32 lowest_freq;
 
     int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
     if (ret)
             return ret;
 
+   if (quirks && quirks->lowest_freq)
+           lowest_freq = quirks->lowest_freq;
+   else
+           lowest_freq = cppc_perf.lowest_freq;
+
     /* Switch to khz */
-   return cppc_perf.lowest_freq * 1000;
+   return lowest_freq * 1000;
   }
 
   static int amd_get_max_freq(struct amd_cpudata *cpudata) @@
-635,12
+669,18 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
   static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
   {
     struct cppc_perf_caps cppc_perf;
+   u32 nominal_freq;
 
     int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
     if (ret)
             return ret;
 
-   return cppc_perf.nominal_freq;
+   if (quirks && quirks->nominal_freq)
+           nominal_freq = quirks->nominal_freq;
+   else
+           nominal_freq = cppc_perf.nominal_freq;
+
+   return nominal_freq;
   }
Quoted 2 lines
Quoted 2 lines
Quoted 2 lines

static int amd_get_lowest_nonlinear_freq(struct amd_cpudata
*cpudata) @@ -1672,6 +1712,11 @@ static int __init

amd_pstate_init(void)

Quoted 28 lines
Quoted 27 lines

include/linux/amd-pstate.h static const char * const

Quoted 16 lines
     if (cpufreq_get_current_driver())
             return -EEXIST;
drivers/cpufreq/amd-pstate.c +5 -0
+   quirks = NULL;
+
+   /* check if this machine need CPPC quirks */
+   dmi_check_system(amd_pstate_quirks_table);
+
     switch (cppc_state) {
     case AMD_PSTATE_UNDEFINED:
             /* Disable on the following configs by default:
include/linux/amd-pstate.h +0 -0
index d21838835abd..7b2cbb892fd9 100644
@@ -124,4 +124,10 @@ static const char * const

amd_pstate_mode_string[] = {

Quoted 10 lines
include/linux/amd-pstate.h +6 -0
     [AMD_PSTATE_GUIDED]      = "guided",
     NULL,
   };
+
+struct quirk_entry {
+   u32 nominal_freq;
+   u32 lowest_freq;
+};
+
   #endif /* _LINUX_AMD_PSTATE_H */