Skip to contentSkip to conversation

AMD Pstate Driver Core Performance Boost

PATCH Superseded Perry Yuan 3 participants 18 messages Mar 13, 2024 – Mar 14, 2024

Subsystems (4)

v4 of 13 Superseded Latest is v13 →

lore
Share & tools
lore

Perry Yuan

author reviewer
#0 lore raw

v4 cover AMD Pstate Driver Core Performance Boost

Hi all,
The patchset series add core performance boost feature for AMD pstate driver including passisve ,guide and active mode support.

User can change core frequency boost control with a new sysfs entry:

"/sys/devices/system/cpu/amd_pstate/cpb_boost"

The legancy boost interface has been removed due to the function conflict with new cpb_boost which can support all modes.

1). enable core boost:

$ sudo bash -c "echo 0 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ   MINMHZ      MHZ
  0    0      0    0 0:0:0:0          yes 4201.0000 400.0000 2983.578
  1    0      0    1 1:1:1:0          yes 4201.0000 400.0000 2983.578
  2    0      0    2 2:2:2:0          yes 4201.0000 400.0000 2583.855
  3    0      0    3 3:3:3:0          yes 4201.0000 400.0000 2983.578
  4    0      0    4 4:4:4:0          yes 4201.0000 400.0000 2983.578

2). disabble core boost:

$ sudo bash -c "echo 1 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
   0    0      0    0 0:0:0:0          yes 5759.0000 400.0000 2983.578
  1    0      0    1 1:1:1:0          yes 5759.0000 400.0000 2983.578
  2    0      0    2 2:2:2:0          yes 5759.0000 400.0000 2983.578
  3    0      0    3 3:3:3:0          yes 5759.0000 400.0000 2983.578
  4    0      0    4 4:4:4:0          yes 5759.0000 400.0000 2983.578

The patches have been tested with the AMD 7950X processor and many users would like to get core boost control enabled for power saving.

If you would like to test this patchset, it needs to apply the patchset based on below one latest version patchset.
https://lore.kernel.org/lkml/20240208102122.GAZcSrIkbPJfIExdF6@fat_crate.local/

Perry.

Changes from v3:
* rebased to linux-pm/bleeding-edge v6.8
* rename global to amd_pstate_global_params(Oleksandr Natalenko)
* remove comments for boot_supported in amd_pstate.h
* fix the compiler warning for amd-pstate-ut.ko
* use for_each_online_cpu in cpb_boost_store which fix the null pointer error during testing
* fix the max frequency value to be KHz when cpb boost disabled(Gautham R. Shenoy)

Changes from v2:
* move global struct to amd-pstate.h
* fix the amd-pstate-ut with new cpb control interface

Changes from v1:
* drop suspend/resume fix patch 6/7 because of the fix should be in another fix series instead of CPB feature
* move the set_boost remove patch to the last(Mario)
* Fix commit info with "Closes:" (Mario)
* simplified global.cpb_supported initialization(Mario)
* Add guide mode support for CPB control
* Fixed some Doc typos and add guide mode info to Doc as well.

v1: https://lore.kernel.org/all/[email protected]/
v2: https://lore.kernel.org/lkml/[email protected]/
v3: https://lore.kernel.org/lkml/[email protected]/

Perry Yuan (7):
cpufreq: amd-pstate: initialize new core precision boost state
cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control
cpufreq: amd-pstate: fix max_perf calculation for amd_get_max_freq()
cpufreq: amd-pstate: fix the MSR highest perf will be reset issue
while cpb boost off
Documentation: cpufreq: amd-pstate: introduce the new cpu boost
control method
cpufreq: amd-pstate: remove legacy set_boost callback for passive mode
cpufreq: amd-pstate-ut: support new cpb boost control interface

 Documentation/admin-guide/pm/amd-pstate.rst |  11 ++
 drivers/cpufreq/amd-pstate-ut.c             |   2 +-
 drivers/cpufreq/amd-pstate.c                | 157 +++++++++++++++-----
 include/linux/amd-pstate.h                  |  16 +-
 4 files changed, 149 insertions(+), 37 deletions(-)
Signature · 1 line
2.34.1
author reviewer
#1 lore raw

PATCH v4 1/7 cpufreq: amd-pstate: initialize new core precision boost state

From: Perry Yuan <[email protected]>

Add gloal global_params to represent current CPU Performance Boost(cpb) state for cpu frequency scaling, both active and passive modes all can support CPU cores frequency boosting control which is based on the BIOS setting, while BIOS turn on the "Core Performance Boost", it will allow OS control each core highest perf limitation from OS side.

If core performance boost is disabled while a core is in a boosted P-state, the core transitions to the highest performance non-boosted P-state, that is the same as the nominal frequency limit.

---
 drivers/cpufreq/amd-pstate.c | 50 ++++++++++++------------------------
 include/linux/amd-pstate.h   | 14 ++++++++++
 2 files changed, 31 insertions(+), 33 deletions(-)
drivers/cpufreq/amd-pstate.c +17 -33
index 2015c9fcc3c9..ef6381b48e76 100644
@@ -67,6 +67,8 @@ 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;
+struct amd_pstate_global_params amd_pstate_global_params;
+EXPORT_SYMBOL_GPL(amd_pstate_global_params);
 
 /*
  * AMD Energy Preference Performance (EPP)
@@ -676,43 +678,21 @@ static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
 	return lowest_nonlinear_freq * 1000;
 }
 
-static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
+static int amd_pstate_boost_init(struct amd_cpudata *cpudata)
 {
-	struct amd_cpudata *cpudata = policy->driver_data;
+	u64 boost_val;
 	int ret;
 
-	if (!cpudata->boost_supported) {
-		pr_err("Boost mode is not supported by this processor or SBIOS\n");
-		return -EINVAL;
-	}
-
-	if (state)
-		policy->cpuinfo.max_freq = cpudata->max_freq;
-	else
-		policy->cpuinfo.max_freq = cpudata->nominal_freq;
-
-	policy->max = policy->cpuinfo.max_freq;
-
-	ret = freq_qos_update_request(&cpudata->req[1],
-				      policy->cpuinfo.max_freq);
-	if (ret < 0)
+	ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
+	if (ret) {
+		pr_err_once("failed to read initial CPU boost state!\n");
 		return ret;
+	}
 
-	return 0;
-}
-
-static void amd_pstate_boost_init(struct amd_cpudata *cpudata)
-{
-	u32 highest_perf, nominal_perf;
-
-	highest_perf = READ_ONCE(cpudata->highest_perf);
-	nominal_perf = READ_ONCE(cpudata->nominal_perf);
-
-	if (highest_perf <= nominal_perf)
-		return;
+	amd_pstate_global_params.cpb_supported = !((boost_val >> 25) & 0x1);
+	amd_pstate_global_params.cpb_boost = amd_pstate_global_params.cpb_supported;
 
-	cpudata->boost_supported = true;
-	current_pstate_driver->boost_enabled = true;
+	return ret;
 }
 
 static void amd_perf_ctl_reset(unsigned int cpu)
@@ -855,6 +835,9 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
+	/* initialize cpu cores boot state */
+	amd_pstate_boost_init(cpudata);
+
 	min_freq = amd_get_min_freq(cpudata);
 	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
@@ -906,7 +889,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 
 	policy->driver_data = cpudata;
 
-	amd_pstate_boost_init(cpudata);
 	if (!current_pstate_driver->adjust_perf)
 		current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
 
@@ -1317,6 +1299,9 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
+	/* initialize cpu cores boot state */
+	amd_pstate_boost_init(cpudata);
+
 	min_freq = amd_get_min_freq(cpudata);
 	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
@@ -1367,7 +1352,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 			return ret;
 		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
 	}
-	amd_pstate_boost_init(cpudata);
 
 	return 0;
 
include/linux/amd-pstate.h +14 -0
index d21838835abd..c6e2a97913de 100644
@@ -124,4 +124,18 @@ static const char * const amd_pstate_mode_string[] = {
 	[AMD_PSTATE_GUIDED]      = "guided",
 	NULL,
 };
+
+/**
+ * struct amd_pstate_global_params - Global parameters, mostly tunable via sysfs.
+ * @cpb_boost:		Whether or not to use boost CPU P-states.
+ * @cpb_supported:	Whether or not CPU boost P-states are available
+ *			based on the MSR_K7_HWCR bit[25] state
+ */
+struct amd_pstate_global_params {
+	bool cpb_boost;
+	bool cpb_supported;
+};
+
+extern struct amd_pstate_global_params amd_pstate_global_params;
+
 #endif /* _LINUX_AMD_PSTATE_H */
Signature · 1 line
2.34.1
author reviewer
#4 lore raw

PATCH v4 2/7 cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control

In reply to Perry Yuan

From: Perry Yuan <[email protected]>

With this new sysfs entry cpb_boostcreated, user can change CPU boost state dynamically under active, guided and passive modes. And the highest perf and frequency will also be updated as the boost state changing.

0): check current boost state
cat /sys/devices/system/cpu/amd_pstate/cpb_boost

1): disable CPU boost
sudo bash -c "echo 0 > /sys/devices/system/cpu/amd_pstate/cpb_boost"

2): enable CPU boost
sudo bash -c "echo 1 > /sys/devices/system/cpu/amd_pstate/cpb_boost"

---
 drivers/cpufreq/amd-pstate.c | 97 ++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
drivers/cpufreq/amd-pstate.c +97 -0
index ef6381b48e76..d54399ebb758 100644
@@ -1208,6 +1208,101 @@ static ssize_t prefcore_show(struct device *dev,
 	return sysfs_emit(buf, "%s\n", str_enabled_disabled(amd_pstate_prefcore));
 }
 
+static int amd_cpu_boost_update(struct amd_cpudata *cpudata, u32 on)
+{
+	struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpudata->cpu);
+	struct cppc_perf_ctrls perf_ctrls;
+	u32 highest_perf, nominal_perf;
+	int ret;
+
+	if (!policy)
+		return -ENODATA;
+
+	highest_perf = READ_ONCE(cpudata->highest_perf);
+	nominal_perf = READ_ONCE(cpudata->nominal_perf);
+
+	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+		u64 value = READ_ONCE(cpudata->cppc_req_cached);
+
+		value &= ~GENMASK_ULL(7, 0);
+		value |= on ? highest_perf : nominal_perf;
+		WRITE_ONCE(cpudata->cppc_req_cached, value);
+
+		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
+
+	} else {
+		perf_ctrls.max_perf = on ? highest_perf : nominal_perf;
+		ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1);
+		if (ret) {
+			pr_debug("failed to set energy perf value (%d)\n", ret);
+			return ret;
+		}
+	}
+
+	if (on)
+		policy->cpuinfo.max_freq = cpudata->max_freq;
+	else
+		policy->cpuinfo.max_freq = cpudata->nominal_freq * 1000;
+
+	policy->max = policy->cpuinfo.max_freq;
+
+	if (cppc_state == AMD_PSTATE_PASSIVE) {
+		ret = freq_qos_update_request(&cpudata->req[1],
+				      policy->cpuinfo.max_freq);
+	}
+
+	cpufreq_cpu_release(policy);
+
+	return ret;
+}
+
+static ssize_t cpb_boost_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%u\n", amd_pstate_global_params.cpb_boost);
+}
+
+static ssize_t cpb_boost_store(struct device *dev, struct device_attribute *b,
+			    const char *buf, size_t count)
+{
+	bool new_state;
+	ssize_t ret;
+	int cpu;
+
+	mutex_lock(&amd_pstate_driver_lock);
+	if (!amd_pstate_global_params.cpb_supported) {
+		pr_err("Boost mode is not supported by this processor or SBIOS\n");
+		return -EINVAL;
+	}
+
+	ret = kstrtobool(buf, &new_state);
+	if (ret)
+		return -EINVAL;
+
+	amd_pstate_global_params.cpb_boost = !!new_state;
+
+	for_each_online_cpu(cpu) {
+
+		struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+		struct amd_cpudata *cpudata = policy->driver_data;
+
+		if (!cpudata) {
+			pr_err("cpudata is NULL\n");
+			ret = -ENODATA;
+			cpufreq_cpu_put(policy);
+			goto err_exit;
+		}
+
+		amd_cpu_boost_update(cpudata, amd_pstate_global_params.cpb_boost);
+		refresh_frequency_limits(policy);
+		cpufreq_cpu_put(policy);
+	}
+
+err_exit:
+	mutex_unlock(&amd_pstate_driver_lock);
+	return ret < 0 ? ret : count;
+}
+
 cpufreq_freq_attr_ro(amd_pstate_max_freq);
 cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
 
@@ -1218,6 +1313,7 @@ cpufreq_freq_attr_rw(energy_performance_preference);
 cpufreq_freq_attr_ro(energy_performance_available_preferences);
 static DEVICE_ATTR_RW(status);
 static DEVICE_ATTR_RO(prefcore);
+static DEVICE_ATTR_RW(cpb_boost);
 
 static struct freq_attr *amd_pstate_attr[] = {
 	&amd_pstate_max_freq,
@@ -1242,6 +1338,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {
 static struct attribute *pstate_global_attributes[] = {
 	&dev_attr_status.attr,
 	&dev_attr_prefcore.attr,
+	&dev_attr_cpb_boost.attr,
 	NULL
 };
 
Signature · 1 line
2.34.1
author reviewer
#7 lore raw

PATCH v4 3/7 cpufreq: amd-pstate: fix max_perf calculation for amd_get_max_freq()

In reply to Perry Yuan

From: Perry Yuan <[email protected]>

When CPU core Precision Boost state changed, the max frequency will also need to be updated according to the current boost state, if boost is disabled now, the max perf will be limited to nominal perf values. otherwise the max frequency will be showed wrongly.

---
 drivers/cpufreq/amd-pstate.c | 4 ++++
 1 file changed, 4 insertions(+)
drivers/cpufreq/amd-pstate.c +4 -0
index d54399ebb758..0965fbf660dd 100644
@@ -632,6 +632,10 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	max_perf = READ_ONCE(cpudata->highest_perf);
 
+	/* when boost is off, the highest perf will be limited to nominal_perf */
+	if (!amd_pstate_global_params.cpb_boost)
+		max_perf = nominal_perf;
+
 	boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT,
 			      nominal_perf);
 
Signature · 1 line
2.34.1
author reviewer
#9 lore raw

PATCH v4 4/7 cpufreq: amd-pstate: fix the MSR highest perf will be reset issue while cpb boost off

In reply to Perry Yuan

From: Perry Yuan <[email protected]>

Select the min perf to fix the highest perf value while update pstate CPPC request MSR register, here we need to limit the max perf value when CPU boost is disabled in case of that highest perf value in the MSR will be reset to original highest perf value which cause the BOOST control failed.

---
 drivers/cpufreq/amd-pstate.c | 5 +++++
 1 file changed, 5 insertions(+)
drivers/cpufreq/amd-pstate.c +5 -0
index 0965fbf660dd..d7afbded6e3d 100644
@@ -440,6 +440,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 			      u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags)
 {
 	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
+	u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	u64 value = prev;
 
 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
@@ -459,6 +460,10 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 	value &= ~AMD_CPPC_DES_PERF(~0L);
 	value |= AMD_CPPC_DES_PERF(des_perf);
 
+	/* limit the max perf when core performance boost feature is disabled */
+	if (!amd_pstate_global_params.cpb_boost)
+		max_perf = min_t(unsigned long, nominal_perf, max_perf);
+
 	value &= ~AMD_CPPC_MAX_PERF(~0L);
 	value |= AMD_CPPC_MAX_PERF(max_perf);
 
Signature · 1 line
2.34.1
author reviewer
#11 lore raw

PATCH v4 5/7 Documentation: cpufreq: amd-pstate: introduce the new cpu boost control method

In reply to Perry Yuan

From: Perry Yuan <[email protected]>

Introduce AMD CPU frequency boosting control sysfs entry which used for switching boost on and boost off.

If core performance boost is disabled while a core is in a boosted P-state, the core automatically transitions to the highest performance non-boosted P-state The highest perf and frequency will be limited by the setting value.

---
 Documentation/admin-guide/pm/amd-pstate.rst | 11 +++++++++++
 1 file changed, 11 insertions(+)
Documentation/admin-guide/pm/amd-pstate.rst +11 -0
index 1e0d101b020a..82fbd01da658 100644
@@ -440,6 +440,17 @@ control its functionality at the system level.  They are located in the
         This attribute is read-only to check the state of preferred core set
         by the kernel parameter.
 
+``cpb_boost``
+        Specifies whether core performance boost is requested to be enabled or disabled
+        If core performance boost is disabled while a core is in a boosted P-state, the
+        core automatically transitions to the highest performance non-boosted P-state.
+        AMD Core Performance Boost(CPB) is controlled by this new attribute file which
+        allow user to change all cores frequency boosting state. It supports both
+        ``active``, ``passive`` and ``guided`` mode control with below value write to it.
+
+        "0" Disable Core Performance Boosting
+        "1" Enable  Core Performance Boosting
+
 ``cpupower`` tool support for ``amd-pstate``
 ===============================================
 
Signature · 1 line
2.34.1
author reviewer
#12 lore raw

PATCH v4 6/7 cpufreq: amd-pstate: remove legacy set_boost callback for passive mode

In reply to Perry Yuan

With new freqency boost interface supported, legacy boost control doesn't make sense any more which only support passive mode. so it can remove the legacy set_boost interface from amd-pstate driver in case of there is conflict with new boost control logic.

---
 drivers/cpufreq/amd-pstate.c | 1 -
 include/linux/amd-pstate.h   | 2 --
 2 files changed, 3 deletions(-)
drivers/cpufreq/amd-pstate.c +0 -1
index d7afbded6e3d..4a24db868cb1 100644
@@ -1689,7 +1689,6 @@ static struct cpufreq_driver amd_pstate_driver = {
 	.exit		= amd_pstate_cpu_exit,
 	.suspend	= amd_pstate_cpu_suspend,
 	.resume		= amd_pstate_cpu_resume,
-	.set_boost	= amd_pstate_set_boost,
 	.update_limits	= amd_pstate_update_limits,
 	.name		= "amd-pstate",
 	.attr		= amd_pstate_attr,
include/linux/amd-pstate.h +0 -2
index c6e2a97913de..7130b297c522 100644
@@ -56,7 +56,6 @@ struct amd_aperf_mperf {
  * @cur: Difference of Aperf/Mperf/tsc count between last and current sample
  * @prev: Last Aperf/Mperf/tsc count value read from register
  * @freq: current cpu frequency value
- * @boost_supported: check whether the Processor or SBIOS supports boost mode
  * @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.
@@ -93,7 +92,6 @@ struct amd_cpudata {
 	struct amd_aperf_mperf prev;
 
 	u64	freq;
-	bool	boost_supported;
 	bool	hw_prefcore;
 
 	/* EPP feature related attributes*/
Signature · 1 line
2.34.1
author reviewer
#15 lore raw

PATCH v4 7/7 cpufreq: amd-pstate-ut: support new cpb boost control interface

In reply to Perry Yuan

As the new CPB boost control is enabled, pstate unit test needs to remove legacy boost_supported check and start to use new CPB boost control interface global.cpb_boost.

---
 drivers/cpufreq/amd-pstate-ut.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/cpufreq/amd-pstate-ut.c +1 -1
index f04ae67dda37..b3601b0e6dd3 100644
@@ -226,7 +226,7 @@ static void amd_pstate_ut_check_freq(u32 index)
 			goto skip_test;
 		}
 
-		if (cpudata->boost_supported) {
+		if (amd_pstate_global_params.cpb_boost) {
 			if ((policy->max == cpudata->max_freq) ||
 					(policy->max == cpudata->nominal_freq))
 				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
Signature · 1 line
2.34.1
#16 lore raw
In reply to Perry Yuan
Quoted 40 lines · CET Perry Yuan

Hi all,
The patchset series add core performance boost feature for AMD pstate driver including passisve ,guide and active mode support.

User can change core frequency boost control with a new sysfs entry:

"/sys/devices/system/cpu/amd_pstate/cpb_boost"

The legancy boost interface has been removed due to the function conflict with new cpb_boost which can support all modes.

1). enable core boost:

$ sudo bash -c "echo 0 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ   MINMHZ      MHZ
  0    0      0    0 0:0:0:0          yes 4201.0000 400.0000 2983.578
  1    0      0    1 1:1:1:0          yes 4201.0000 400.0000 2983.578
  2    0      0    2 2:2:2:0          yes 4201.0000 400.0000 2583.855
  3    0      0    3 3:3:3:0          yes 4201.0000 400.0000 2983.578
  4    0      0    4 4:4:4:0          yes 4201.0000 400.0000 2983.578

2). disabble core boost:

$ sudo bash -c "echo 1 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
   0    0      0    0 0:0:0:0          yes 5759.0000 400.0000 2983.578
  1    0      0    1 1:1:1:0          yes 5759.0000 400.0000 2983.578
  2    0      0    2 2:2:2:0          yes 5759.0000 400.0000 2983.578
  3    0      0    3 3:3:3:0          yes 5759.0000 400.0000 2983.578
  4    0      0    4 4:4:4:0          yes 5759.0000 400.0000 2983.578

The patches have been tested with the AMD 7950X processor and many users would like to get core boost control enabled for power saving.

If you would like to test this patchset, it needs to apply the patchset based on below one latest version patchset.
https://lore.kernel.org/lkml/20240208102122.GAZcSrIkbPJfIExdF6@fat_crate.local/

Quoted 6 lines

Perry.

Changes from v3:
* rebased to linux-pm/bleeding-edge v6.8
* rename global to amd_pstate_global_params(Oleksandr Natalenko)

Would appreciate being in Cc: then.

Quoted 41 lines

* remove comments for boot_supported in amd_pstate.h
* fix the compiler warning for amd-pstate-ut.ko
* use for_each_online_cpu in cpb_boost_store which fix the null pointer error during testing
* fix the max frequency value to be KHz when cpb boost disabled(Gautham R. Shenoy)

Changes from v2:
* move global struct to amd-pstate.h
* fix the amd-pstate-ut with new cpb control interface

Changes from v1:
* drop suspend/resume fix patch 6/7 because of the fix should be in another fix series instead of CPB feature
* move the set_boost remove patch to the last(Mario)
* Fix commit info with "Closes:" (Mario)
* simplified global.cpb_supported initialization(Mario)
* Add guide mode support for CPB control
* Fixed some Doc typos and add guide mode info to Doc as well.

v1: https://lore.kernel.org/all/[email protected]/
v2: https://lore.kernel.org/lkml/[email protected]/
v3: https://lore.kernel.org/lkml/[email protected]/

Perry Yuan (7):
cpufreq: amd-pstate: initialize new core precision boost state
cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control
cpufreq: amd-pstate: fix max_perf calculation for amd_get_max_freq()
cpufreq: amd-pstate: fix the MSR highest perf will be reset issue
while cpb boost off
Documentation: cpufreq: amd-pstate: introduce the new cpu boost
control method
cpufreq: amd-pstate: remove legacy set_boost callback for passive mode
cpufreq: amd-pstate-ut: support new cpb boost control interface

 Documentation/admin-guide/pm/amd-pstate.rst |  11 ++
 drivers/cpufreq/amd-pstate-ut.c             |   2 +-
 drivers/cpufreq/amd-pstate.c                | 157 +++++++++++++++-----
 include/linux/amd-pstate.h                  |  16 +-
 4 files changed, 149 insertions(+), 37 deletions(-)
Signature · 1 line
Oleksandr Natalenko (post-factum)
author reviewer
#17 lore raw

[AMD Official Use Only - General]

Quoted 56 lines

-----Original Message-----
From: Oleksandr Natalenko <[email protected]>
Sent: Wednesday, March 13, 2024 10:49 PM
To: [email protected]; Limonciello, Mario <[email protected]>; [email protected]; Huang, Ray <[email protected]>; Shenoy, Gautham Ranjal <[email protected]>; Petkov, Borislav <[email protected]>; Yuan, Perry <[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 v4 0/7] AMD Pstate Driver Core Performance Boost

Quoted 41 lines · CET Perry Yuan

Hi all,
The patchset series add core performance boost feature for AMD pstate driver including passisve ,guide and active mode support.

User can change core frequency boost control with a new sysfs entry:

"/sys/devices/system/cpu/amd_pstate/cpb_boost"

The legancy boost interface has been removed due to the function conflict with new cpb_boost which can support all modes.

1). enable core boost:

$ sudo bash -c "echo 0 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE    MAXMHZ   MINMHZ      MHZ
  0    0      0    0 0:0:0:0          yes 4201.0000 400.0000 2983.578
  1    0      0    1 1:1:1:0          yes 4201.0000 400.0000 2983.578
  2    0      0    2 2:2:2:0          yes 4201.0000 400.0000 2583.855
  3    0      0    3 3:3:3:0          yes 4201.0000 400.0000 2983.578
  4    0      0    4 4:4:4:0          yes 4201.0000 400.0000 2983.578

2). disabble core boost:

$ sudo bash -c "echo 1 > /sys/devices/system/cpu/amd_pstate/cpb_boost"
$ lscpu -ae
   0    0      0    0 0:0:0:0          yes 5759.0000 400.0000 2983.578
  1    0      0    1 1:1:1:0          yes 5759.0000 400.0000 2983.578
  2    0      0    2 2:2:2:0          yes 5759.0000 400.0000 2983.578
  3    0      0    3 3:3:3:0          yes 5759.0000 400.0000 2983.578
  4    0      0    4 4:4:4:0          yes 5759.0000 400.0000 2983.578

The patches have been tested with the AMD 7950X processor and many users would like to get core boost control enabled for power saving.

If you would like to test this patchset, it needs to apply the patchset based on below one latest version patchset.
https://lore.kernel.org/lkml/20240208102122.GAZcSrIkbPJfIExdF6@fat_cra
te.local/

Quoted 8 lines
Quoted 6 lines

Perry.

Changes from v3:
* rebased to linux-pm/bleeding-edge v6.8
* rename global to amd_pstate_global_params(Oleksandr Natalenko)

Would appreciate being in Cc: then.

Sure, thanks for your feedback,
Will update Cc list in next version.

Perry.

Quoted 50 lines
Quoted 39 lines

* remove comments for boot_supported in amd_pstate.h
* fix the compiler warning for amd-pstate-ut.ko
* use for_each_online_cpu in cpb_boost_store which fix the null pointer error during testing
* fix the max frequency value to be KHz when cpb boost
disabled(Gautham R. Shenoy)

Changes from v2:
* move global struct to amd-pstate.h
* fix the amd-pstate-ut with new cpb control interface

Changes from v1:
* drop suspend/resume fix patch 6/7 because of the fix should be in another fix series instead of CPB feature
* move the set_boost remove patch to the last(Mario)
* Fix commit info with "Closes:" (Mario)
* simplified global.cpb_supported initialization(Mario)
* Add guide mode support for CPB control
* Fixed some Doc typos and add guide mode info to Doc as well.

v1:
https://lore.kernel.org/all/[email protected]/
v2:
https://lore.kernel.org/lkml/[email protected]/
v3:
https://lore.kernel.org/lkml/[email protected]/

Perry Yuan (7):
cpufreq: amd-pstate: initialize new core precision boost state
cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control
cpufreq: amd-pstate: fix max_perf calculation for amd_get_max_freq()
cpufreq: amd-pstate: fix the MSR highest perf will be reset issue
while cpb boost off
Documentation: cpufreq: amd-pstate: introduce the new cpu boost
control method
cpufreq: amd-pstate: remove legacy set_boost callback for passive mode
cpufreq: amd-pstate-ut: support new cpb boost control interface

Quoted 7 lines
 Documentation/admin-guide/pm/amd-pstate.rst |  11 ++
 drivers/cpufreq/amd-pstate-ut.c             |   2 +-
 drivers/cpufreq/amd-pstate.c                | 157 +++++++++++++++-----
 include/linux/amd-pstate.h                  |  16 +-
 4 files changed, 149 insertions(+), 37 deletions(-)

--
Oleksandr Natalenko (post-factum)

#2 lore raw

Re: [PATCH v4 1/7] cpufreq: amd-pstate: initialize new core precision boost state

In reply to Perry Yuan
Quoted 68 lines · Perry Yuan

From: Perry Yuan <[email protected]>

Add gloal global_params to represent current CPU Performance Boost(cpb) state for cpu frequency scaling, both active and passive modes all can support CPU cores frequency boosting control which is based on the BIOS setting, while BIOS turn on the "Core Performance Boost", it will allow OS control each core highest perf limitation from OS side.

If core performance boost is disabled while a core is in a boosted P-state, the core transitions to the highest performance non-boosted P-state, that is the same as the nominal frequency limit.

---
 drivers/cpufreq/amd-pstate.c | 50 ++++++++++++------------------------
 include/linux/amd-pstate.h   | 14 ++++++++++
 2 files changed, 31 insertions(+), 33 deletions(-)
drivers/cpufreq/amd-pstate.c +8 -20
index 2015c9fcc3c9..ef6381b48e76 100644
@@ -67,6 +67,8 @@ 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;
+struct amd_pstate_global_params amd_pstate_global_params;
+EXPORT_SYMBOL_GPL(amd_pstate_global_params);
 
 /*
  * AMD Energy Preference Performance (EPP)
@@ -676,43 +678,21 @@ static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
 	return lowest_nonlinear_freq * 1000;
 }
 
-static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
+static int amd_pstate_boost_init(struct amd_cpudata *cpudata)
 {
-	struct amd_cpudata *cpudata = policy->driver_data;
+	u64 boost_val;
 	int ret;
 
-	if (!cpudata->boost_supported) {
-		pr_err("Boost mode is not supported by this processor or SBIOS\n");
-		return -EINVAL;
-	}
-
-	if (state)
-		policy->cpuinfo.max_freq = cpudata->max_freq;
-	else
-		policy->cpuinfo.max_freq = cpudata->nominal_freq;
-
-	policy->max = policy->cpuinfo.max_freq;
-
-	ret = freq_qos_update_request(&cpudata->req[1],
-				      policy->cpuinfo.max_freq);
-	if (ret < 0)
+	ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
+	if (ret) {
+		pr_err_once("failed to read initial CPU boost state!\n");
 		return ret;
+	}
 
-	return 0;
-}
-

drivers/cpufreq/amd-pstate.c static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata) · line 692

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +1 -9
-static void amd_pstate_boost_init(struct amd_cpudata *cpudata)
-{
-	u32 highest_perf, nominal_perf;
-
-	highest_perf = READ_ONCE(cpudata->highest_perf);
-	nominal_perf = READ_ONCE(cpudata->nominal_perf);
-
-	if (highest_perf <= nominal_perf)
-		return;
+	amd_pstate_global_params.cpb_supported = !((boost_val >> 25) & 0x1);

Can we move the definition of MSR_K7_HWCR_CPB_DIS from drivers/cpufreq/acpi-cpufreq.h to msr-index.h and use it here ? something like the following:

----------- x8---------------------------------------------------------------------

arch/x86/include/asm/msr-index.h +2 -0
index f1bd7b91b3c6..e5380cad903c 100644
@@ -736,6 +736,8 @@
 #define MSR_K7_HWCR_IRPERF_EN          BIT_ULL(MSR_K7_HWCR_IRPERF_EN_BIT)
 #define MSR_K7_FID_VID_CTL             0xc0010041
 #define MSR_K7_FID_VID_STATUS          0xc0010042
+#define MSR_K7_HWCR_CPB_DIS_BIT                25
+#define MSR_K7_HWCR_CPB_DIS            BIT_ULL(MSR_K7_HWCR_CPB_DIS_BIT)
 
 /* K6 MSRs */
 #define MSR_K6_WHCR                    0xc0000082
drivers/cpufreq/acpi-cpufreq.c +1 -2
index 37f1cdf46d29..7089aca6cc0d 100644
@@ -31,6 +31,7 @@
 #include <acpi/cppc_acpi.h>
 
 #include <asm/msr.h>
+#include <asm/msr-index.h>
 #include <asm/processor.h>
 #include <asm/cpufeature.h>
 #include <asm/cpu_device_id.h>
@@ -50,8 +51,6 @@ enum {
 #define AMD_MSR_RANGE          (0x7)
 #define HYGON_MSR_RANGE                (0x7)
 
-#define MSR_K7_HWCR_CPB_DIS    (1ULL << 25)
-
 struct acpi_cpufreq_data {
        unsigned int resume;
        unsigned int cpu_feature;

The rest of the patch looks good to me.

--
Thanks and Regards
gautham.

Quoted 70 lines
drivers/cpufreq/amd-pstate.c +8 -4
+	amd_pstate_global_params.cpb_boost = amd_pstate_global_params.cpb_supported;
 
-	cpudata->boost_supported = true;
-	current_pstate_driver->boost_enabled = true;
+	return ret;
 }
 
 static void amd_perf_ctl_reset(unsigned int cpu)
@@ -855,6 +835,9 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
+	/* initialize cpu cores boot state */
+	amd_pstate_boost_init(cpudata);
+
 	min_freq = amd_get_min_freq(cpudata);
 	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
@@ -906,7 +889,6 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 
 	policy->driver_data = cpudata;
 
-	amd_pstate_boost_init(cpudata);
 	if (!current_pstate_driver->adjust_perf)
 		current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
 
@@ -1317,6 +1299,9 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 	if (ret)
 		goto free_cpudata1;
 
+	/* initialize cpu cores boot state */
+	amd_pstate_boost_init(cpudata);
+
 	min_freq = amd_get_min_freq(cpudata);
 	max_freq = amd_get_max_freq(cpudata);
 	nominal_freq = amd_get_nominal_freq(cpudata);
@@ -1367,7 +1352,6 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
 			return ret;
 		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
 	}
-	amd_pstate_boost_init(cpudata);
 
 	return 0;
 
include/linux/amd-pstate.h +14 -0
index d21838835abd..c6e2a97913de 100644
@@ -124,4 +124,18 @@ static const char * const amd_pstate_mode_string[] = {
 	[AMD_PSTATE_GUIDED]      = "guided",
 	NULL,
 };
+
+/**
+ * struct amd_pstate_global_params - Global parameters, mostly tunable via sysfs.
+ * @cpb_boost:		Whether or not to use boost CPU P-states.
+ * @cpb_supported:	Whether or not CPU boost P-states are available
+ *			based on the MSR_K7_HWCR bit[25] state
+ */
+struct amd_pstate_global_params {
+	bool cpb_boost;
+	bool cpb_supported;
+};
+
+extern struct amd_pstate_global_params amd_pstate_global_params;
+
 #endif /* _LINUX_AMD_PSTATE_H */
Signature · 1 line
2.34.1
author reviewer
#3 lore raw

RE: [PATCH v4 1/7] cpufreq: amd-pstate: initialize new core precision boost state

[AMD Official Use Only - General]

Quoted 95 lines

-----Original Message-----
From: Shenoy, Gautham Ranjal <[email protected]>
Sent: Thursday, March 14, 2024 5:05 PM
To: Yuan, Perry <[email protected]>
Cc: [email protected]; Limonciello, Mario <[email protected]>; [email protected]; Huang, Ray <[email protected]>; Petkov, Borislav <[email protected]>; 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 v4 1/7] cpufreq: amd-pstate: initialize new core precision boost state

Quoted 15 lines · Perry Yuan

From: Perry Yuan <[email protected]>

Add gloal global_params to represent current CPU Performance Boost(cpb) state for cpu frequency scaling, both active and passive modes all can support CPU cores frequency boosting control which is based on the BIOS setting, while BIOS turn on the "Core Performance Boost", it will allow OS control each core highest perf limitation from OS side.

If core performance boost is disabled while a core is in a boosted P-state, the core transitions to the highest performance non-boosted P-state, that is the same as the nominal frequency limit.

Quoted 7 lines
---
 drivers/cpufreq/amd-pstate.c | 50 ++++++++++++------------------------
 include/linux/amd-pstate.h   | 14 ++++++++++
 2 files changed, 31 insertions(+), 33 deletions(-)
(quoted diff) +0 -0

b/drivers/cpufreq/amd-pstate.c index 2015c9fcc3c9..ef6381b48e76

100644

Quoted 15 lines
drivers/cpufreq/amd-pstate.c +0 -0
@@ -67,6 +67,8 @@ 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;

drivers/cpufreq/amd-pstate.c +2 -0
+struct amd_pstate_global_params amd_pstate_global_params;
+EXPORT_SYMBOL_GPL(amd_pstate_global_params);
 
 /*
  * AMD Energy Preference Performance (EPP) @@ -676,43 +678,21 @@

static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)

    return lowest_nonlinear_freq * 1000;  }

-static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)

drivers/cpufreq/amd-pstate.c

Quoted 8 lines
drivers/cpufreq/amd-pstate.c +2 -3
+static int amd_pstate_boost_init(struct amd_cpudata *cpudata)
 {
-   struct amd_cpudata *cpudata = policy->driver_data;
+   u64 boost_val;
    int ret;
 
-   if (!cpudata->boost_supported) {
-           pr_err("Boost mode is not supported by this processor or

SBIOS\n");

Quoted 21 lines
drivers/cpufreq/amd-pstate.c +4 -15
-           return -EINVAL;
-   }
-
-   if (state)
-           policy->cpuinfo.max_freq = cpudata->max_freq;
-   else
-           policy->cpuinfo.max_freq = cpudata->nominal_freq;
-
-   policy->max = policy->cpuinfo.max_freq;
-
-   ret = freq_qos_update_request(&cpudata->req[1],
-                                 policy->cpuinfo.max_freq);
-   if (ret < 0)
+   ret = rdmsrl_on_cpu(cpudata->cpu, MSR_K7_HWCR, &boost_val);
+   if (ret) {
+           pr_err_once("failed to read initial CPU boost state!\n");
            return ret;
+   }
 
-   return 0;
-}

drivers/cpufreq/amd-pstate.c

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +1 -9
-
-static void amd_pstate_boost_init(struct amd_cpudata *cpudata) -{
-   u32 highest_perf, nominal_perf;
-
-   highest_perf = READ_ONCE(cpudata->highest_perf);
-   nominal_perf = READ_ONCE(cpudata->nominal_perf);
-
-   if (highest_perf <= nominal_perf)
-           return;
+   amd_pstate_global_params.cpb_supported = !((boost_val >> 25) &

0x1);

Quoted 3 lines

Can we move the definition of MSR_K7_HWCR_CPB_DIS from drivers/cpufreq/acpi-cpufreq.h to msr-index.h and use it here ? something like the following:

That's a brilliant idea!
Let me add a new patch to move it in next version.

Perry.

Quoted 42 lines

----------- x8---------------------------------------------------------------------

arch/x86/include/asm/msr- renamed from arch/x86/include/asm/msr-index.h +0 -0

index.h
index f1bd7b91b3c6..e5380cad903c 100644

arch/x86/include/asm/msr-index.h +2 -0
@@ -736,6 +736,8 @@
 #define MSR_K7_HWCR_IRPERF_EN
 BIT_ULL(MSR_K7_HWCR_IRPERF_EN_BIT)
 #define MSR_K7_FID_VID_CTL             0xc0010041
 #define MSR_K7_FID_VID_STATUS          0xc0010042
+#define MSR_K7_HWCR_CPB_DIS_BIT                25
+#define MSR_K7_HWCR_CPB_DIS
 BIT_ULL(MSR_K7_HWCR_CPB_DIS_BIT)
 

/* K6 MSRs */
#define MSR_K6_WHCR 0xc0000082

drivers/cpufreq/acpi-cpufreq.c +1 -2
index 37f1cdf46d29..7089aca6cc0d 100644
@@ -31,6 +31,7 @@
 #include <acpi/cppc_acpi.h>
 
 #include <asm/msr.h>
+#include <asm/msr-index.h>
 #include <asm/processor.h>
 #include <asm/cpufeature.h>
 #include <asm/cpu_device_id.h>
@@ -50,8 +51,6 @@ enum {
 #define AMD_MSR_RANGE          (0x7)
 #define HYGON_MSR_RANGE                (0x7)
 
-#define MSR_K7_HWCR_CPB_DIS    (1ULL << 25)
-
 struct acpi_cpufreq_data {
        unsigned int resume;
        unsigned int cpu_feature;
Quoted 1 line

The rest of the patch looks good to me.

Thank you for the review!

Quoted 84 lines

--
Thanks and Regards
gautham.

Quoted 13 lines
drivers/cpufreq/amd-pstate.c +3 -2
+   amd_pstate_global_params.cpb_boost =
+amd_pstate_global_params.cpb_supported;
 
-   cpudata->boost_supported = true;
-   current_pstate_driver->boost_enabled = true;
+   return ret;
 }
 
 static void amd_perf_ctl_reset(unsigned int cpu) @@ -855,6 +835,9 @@

static int amd_pstate_cpu_init(struct cpufreq_policy *policy)

    if (ret)
            goto free_cpudata1;

drivers/cpufreq/amd-pstate.c

Quoted 6 lines
drivers/cpufreq/amd-pstate.c +3 -0
+   /* initialize cpu cores boot state */
+   amd_pstate_boost_init(cpudata);
+
    min_freq = amd_get_min_freq(cpudata);
    max_freq = amd_get_max_freq(cpudata);
    nominal_freq = amd_get_nominal_freq(cpudata); @@ -906,7 +889,6

@@

Quoted 7 lines

static int amd_pstate_cpu_init(struct cpufreq_policy *policy)

    policy->driver_data = cpudata;
-   amd_pstate_boost_init(cpudata);
    if (!current_pstate_driver->adjust_perf)
            current_pstate_driver->adjust_perf =

amd_pstate_adjust_perf;

drivers/cpufreq/amd-pstate.c static int amd_pstate_epp_cpu_init(struct

Quoted 2 lines
drivers/cpufreq/amd-pstate.c +0 -0
@@ -1317,6 +1299,9 @@ static int amd_pstate_epp_cpu_init(struct

cpufreq_policy *policy)

drivers/cpufreq/amd-pstate.c static int amd_pstate_epp_cpu_init(struct · line 1307

Quoted 9 lines
drivers/cpufreq/amd-pstate.c +3 -0
    if (ret)
            goto free_cpudata1;
 
+   /* initialize cpu cores boot state */
+   amd_pstate_boost_init(cpudata);
+
    min_freq = amd_get_min_freq(cpudata);
    max_freq = amd_get_max_freq(cpudata);
    nominal_freq = amd_get_nominal_freq(cpudata); @@ -1367,7

+1352,6 @@

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

Quoted 13 lines

static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)

                    return ret;
            WRITE_ONCE(cpudata->cppc_cap1_cached, value);
    }
drivers/cpufreq/amd-pstate.c +0 -1
-   amd_pstate_boost_init(cpudata);
 
    return 0;
include/linux/amd-pstate.h +0 -0
index d21838835abd..c6e2a97913de 100644
@@ -124,4 +124,18 @@ static const char * const

amd_pstate_mode_string[] = {

include/linux/amd-pstate.h static const char * const · line 129

Quoted 6 lines
include/linux/amd-pstate.h +3 -0
    [AMD_PSTATE_GUIDED]      = "guided",
    NULL,
 };
+
+/**
+ * struct amd_pstate_global_params - Global parameters, mostly tunable

via sysfs.

Quoted 15 lines
include/linux/amd-pstate.h +11 -1
+ * @cpb_boost:             Whether or not to use boost CPU P-states.
+ * @cpb_supported: Whether or not CPU boost P-states are available
+ *                 based on the MSR_K7_HWCR bit[25] state
+ */
+struct amd_pstate_global_params {
+   bool cpb_boost;
+   bool cpb_supported;
+};
+
+extern struct amd_pstate_global_params amd_pstate_global_params;
+
 #endif /* _LINUX_AMD_PSTATE_H */
--

2.34.1

#5 lore raw

Re: [PATCH v4 2/7] cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control

In reply to Perry Yuan

Hello Perry,

Quoted 9 lines · Perry Yuan

From: Perry Yuan <[email protected]>

With this new sysfs entry cpb_boostcreated, user can change CPU boost state dynamically under active, guided and passive modes. And the highest perf and frequency will also be updated as the boost state changing.

0): check current boost state
cat /sys/devices/system/cpu/amd_pstate/cpb_boost

Could you please elaborate on the need for this new interface when /sys/devices/system/cpu/cpufreq/boost exists and is being used in the other cpufreq driver namely the acpi-cpufreq driver ?

The semantics of this new interface seems to be identical to the existing boost interface.

I am ok with the rest of the patch, but please explain the need for a new interface.

--
Thanks and Regards
gautham.

Quoted 139 lines

1): disable CPU boost
sudo bash -c "echo 0 > /sys/devices/system/cpu/amd_pstate/cpb_boost"

2): enable CPU boost
sudo bash -c "echo 1 > /sys/devices/system/cpu/amd_pstate/cpb_boost"

---
 drivers/cpufreq/amd-pstate.c | 97 ++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
drivers/cpufreq/amd-pstate.c +97 -0
index ef6381b48e76..d54399ebb758 100644
@@ -1208,6 +1208,101 @@ static ssize_t prefcore_show(struct device *dev,
 	return sysfs_emit(buf, "%s\n", str_enabled_disabled(amd_pstate_prefcore));
 }
 
+static int amd_cpu_boost_update(struct amd_cpudata *cpudata, u32 on)
+{
+	struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpudata->cpu);
+	struct cppc_perf_ctrls perf_ctrls;
+	u32 highest_perf, nominal_perf;
+	int ret;
+
+	if (!policy)
+		return -ENODATA;
+
+	highest_perf = READ_ONCE(cpudata->highest_perf);
+	nominal_perf = READ_ONCE(cpudata->nominal_perf);
+
+	if (boot_cpu_has(X86_FEATURE_CPPC)) {
+		u64 value = READ_ONCE(cpudata->cppc_req_cached);
+
+		value &= ~GENMASK_ULL(7, 0);
+		value |= on ? highest_perf : nominal_perf;
+		WRITE_ONCE(cpudata->cppc_req_cached, value);
+
+		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
+
+	} else {
+		perf_ctrls.max_perf = on ? highest_perf : nominal_perf;
+		ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1);
+		if (ret) {
+			pr_debug("failed to set energy perf value (%d)\n", ret);
+			return ret;
+		}
+	}
+
+	if (on)
+		policy->cpuinfo.max_freq = cpudata->max_freq;
+	else
+		policy->cpuinfo.max_freq = cpudata->nominal_freq * 1000;
+
+	policy->max = policy->cpuinfo.max_freq;
+
+	if (cppc_state == AMD_PSTATE_PASSIVE) {
+		ret = freq_qos_update_request(&cpudata->req[1],
+				      policy->cpuinfo.max_freq);
+	}
+
+	cpufreq_cpu_release(policy);
+
+	return ret;
+}
+
+static ssize_t cpb_boost_show(struct device *dev,
+			   struct device_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%u\n", amd_pstate_global_params.cpb_boost);
+}
+
+static ssize_t cpb_boost_store(struct device *dev, struct device_attribute *b,
+			    const char *buf, size_t count)
+{
+	bool new_state;
+	ssize_t ret;
+	int cpu;
+
+	mutex_lock(&amd_pstate_driver_lock);
+	if (!amd_pstate_global_params.cpb_supported) {
+		pr_err("Boost mode is not supported by this processor or SBIOS\n");
+		return -EINVAL;
+	}
+
+	ret = kstrtobool(buf, &new_state);
+	if (ret)
+		return -EINVAL;
+
+	amd_pstate_global_params.cpb_boost = !!new_state;
+
+	for_each_online_cpu(cpu) {
+
+		struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+		struct amd_cpudata *cpudata = policy->driver_data;
+
+		if (!cpudata) {
+			pr_err("cpudata is NULL\n");
+			ret = -ENODATA;
+			cpufreq_cpu_put(policy);
+			goto err_exit;
+		}
+
+		amd_cpu_boost_update(cpudata, amd_pstate_global_params.cpb_boost);
+		refresh_frequency_limits(policy);
+		cpufreq_cpu_put(policy);
+	}
+
+err_exit:
+	mutex_unlock(&amd_pstate_driver_lock);
+	return ret < 0 ? ret : count;
+}
+
 cpufreq_freq_attr_ro(amd_pstate_max_freq);
 cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
 
@@ -1218,6 +1313,7 @@ cpufreq_freq_attr_rw(energy_performance_preference);
 cpufreq_freq_attr_ro(energy_performance_available_preferences);
 static DEVICE_ATTR_RW(status);
 static DEVICE_ATTR_RO(prefcore);
+static DEVICE_ATTR_RW(cpb_boost);
 
 static struct freq_attr *amd_pstate_attr[] = {
 	&amd_pstate_max_freq,
@@ -1242,6 +1338,7 @@ static struct freq_attr *amd_pstate_epp_attr[] = {
 static struct attribute *pstate_global_attributes[] = {
 	&dev_attr_status.attr,
 	&dev_attr_prefcore.attr,
+	&dev_attr_cpb_boost.attr,
 	NULL
 };
 
Signature · 1 line
2.34.1
Reviewed-by on v4 3/7
#8 lore raw

Re: [PATCH v4 3/7] cpufreq: amd-pstate: fix max_perf calculation for amd_get_max_freq()

In reply to Perry Yuan
Quoted 8 lines · Perry Yuan

From: Perry Yuan <[email protected]>

When CPU core Precision Boost state changed, the max frequency will also need to be updated according to the current boost state, if boost is disabled now, the max perf will be limited to nominal perf values. otherwise the max frequency will be showed wrongly.

Looks good to me.

Quoted 22 lines
---
 drivers/cpufreq/amd-pstate.c | 4 ++++
 1 file changed, 4 insertions(+)
drivers/cpufreq/amd-pstate.c +4 -0
index d54399ebb758..0965fbf660dd 100644
@@ -632,6 +632,10 @@ static int amd_get_max_freq(struct amd_cpudata *cpudata)
 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	max_perf = READ_ONCE(cpudata->highest_perf);
 
+	/* when boost is off, the highest perf will be limited to nominal_perf */
+	if (!amd_pstate_global_params.cpb_boost)
+		max_perf = nominal_perf;
+
 	boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT,
 			      nominal_perf);
 
Signature · 1 line
2.34.1
author reviewer
#6 lore raw

RE: [PATCH v4 2/7] cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control

In reply to Gautham R. Shenoy

[AMD Official Use Only - General]

Regards.
Perry

Quoted 32 lines

-----Original Message-----
From: Shenoy, Gautham Ranjal <[email protected]>
Sent: Thursday, March 14, 2024 5:42 PM
To: Yuan, Perry <[email protected]>
Cc: [email protected]; Limonciello, Mario <[email protected]>; [email protected]; Huang, Ray <[email protected]>; Petkov, Borislav <[email protected]>; 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 v4 2/7] cpufreq: amd-pstate: implement cpb_boost sysfs entry for boost control

Hello Perry,

Quoted 9 lines · Perry Yuan

From: Perry Yuan <[email protected]>

With this new sysfs entry cpb_boostcreated, user can change CPU boost state dynamically under active, guided and passive modes. And the highest perf and frequency will also be updated as the boost state changing.

0): check current boost state
cat /sys/devices/system/cpu/amd_pstate/cpb_boost

Could you please elaborate on the need for this new interface when /sys/devices/system/cpu/cpufreq/boost exists and is being used in the other cpufreq driver namely the acpi-cpufreq driver ?

Quoted 5 lines

The semantics of this new interface seems to be identical to the existing boost interface.

I am ok with the rest of the patch, but please explain the need for a new interface.

The new cpb_boost can support all amd pstate modes including epp, guide,passive,
the old boost interface only support passive mode which leverage the cpufreq.c
Some customers request to add support for the boost control on epp/guide modes,
The legacy interface is not compatible with the new one, with new interface, it is more flexible to add AMD specific control logic to the driver.
Meanwhile, putting the cpb_boost into the unified amd_pstate directory, it makes more sense to change the feature state like status and prefer_core, there will be some other interfaces to be added. So based on that, a new interface can work well and support customer request.

Customer request:

Quoted 2 lines
Quoted 2 lines

Perry.

Quoted 153 lines

--
Thanks and Regards
gautham.

Quoted 10 lines

1): disable CPU boost
sudo bash -c "echo 0 > /sys/devices/system/cpu/amd_pstate/cpb_boost"

2): enable CPU boost
sudo bash -c "echo 1 > /sys/devices/system/cpu/amd_pstate/cpb_boost"

Quoted 7 lines
---
 drivers/cpufreq/amd-pstate.c | 97
++++++++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
(quoted diff) +0 -0

b/drivers/cpufreq/amd-pstate.c index ef6381b48e76..d54399ebb758

100644

drivers/cpufreq/amd-pstate.c static ssize_t prefcore_show(struct device

Quoted 3 lines
drivers/cpufreq/amd-pstate.c +0 -0
@@ -1208,6 +1208,101 @@ static ssize_t prefcore_show(struct device

*dev,

Quoted 15 lines
drivers/cpufreq/amd-pstate.c +11 -0
    return sysfs_emit(buf, "%s\n",
 str_enabled_disabled(amd_pstate_prefcore));
 }
 
+static int amd_cpu_boost_update(struct amd_cpudata *cpudata, u32 on)
+{
+   struct cpufreq_policy *policy = cpufreq_cpu_acquire(cpudata->cpu);
+   struct cppc_perf_ctrls perf_ctrls;
+   u32 highest_perf, nominal_perf;
+   int ret;
+
+   if (!policy)
+           return -ENODATA;
+
+   highest_perf = READ_ONCE(cpudata->highest_perf);

drivers/cpufreq/amd-pstate.c static ssize_t prefcore_show(struct device *dev,

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10 -0
+   nominal_perf = READ_ONCE(cpudata->nominal_perf);
+
+   if (boot_cpu_has(X86_FEATURE_CPPC)) {
+           u64 value = READ_ONCE(cpudata->cppc_req_cached);
+
+           value &= ~GENMASK_ULL(7, 0);
+           value |= on ? highest_perf : nominal_perf;
+           WRITE_ONCE(cpudata->cppc_req_cached, value);
+
+           wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,

value);

drivers/cpufreq/amd-pstate.c static ssize_t prefcore_show(struct device *dev,

Quoted 6 lines
drivers/cpufreq/amd-pstate.c +6 -0
+
+   } else {
+           perf_ctrls.max_perf = on ? highest_perf : nominal_perf;
+           ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1);
+           if (ret) {
+                   pr_debug("failed to set energy perf value (%d)\n",

ret);

Quoted 14 lines
drivers/cpufreq/amd-pstate.c +14 -0
+                   return ret;
+           }
+   }
+
+   if (on)
+           policy->cpuinfo.max_freq = cpudata->max_freq;
+   else
+           policy->cpuinfo.max_freq = cpudata->nominal_freq * 1000;
+
+   policy->max = policy->cpuinfo.max_freq;
+
+   if (cppc_state == AMD_PSTATE_PASSIVE) {
+           ret = freq_qos_update_request(&cpudata->req[1],
+                                 policy->cpuinfo.max_freq);

drivers/cpufreq/amd-pstate.c static ssize_t prefcore_show(struct device *dev,

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10 -0
+   }
+
+   cpufreq_cpu_release(policy);
+
+   return ret;
+}
+
+static ssize_t cpb_boost_show(struct device *dev,
+                      struct device_attribute *attr, char *buf) {
+   return sysfs_emit(buf, "%u\n",

amd_pstate_global_params.cpb_boost);

drivers/cpufreq/amd-pstate.c static ssize_t prefcore_show(struct device *dev,

Quoted 3 lines
drivers/cpufreq/amd-pstate.c +3 -0
+}
+
+static ssize_t cpb_boost_store(struct device *dev, struct device_attribute

*b,

drivers/cpufreq/amd-pstate.c static ssize_t prefcore_show(struct device *dev,

Quoted 8 lines
drivers/cpufreq/amd-pstate.c +8 -0
+                       const char *buf, size_t count) {
+   bool new_state;
+   ssize_t ret;
+   int cpu;
+
+   mutex_lock(&amd_pstate_driver_lock);
+   if (!amd_pstate_global_params.cpb_supported) {
+           pr_err("Boost mode is not supported by this processor or

SBIOS\n");

Quoted 12 lines
drivers/cpufreq/amd-pstate.c +12 -0
+           return -EINVAL;
+   }
+
+   ret = kstrtobool(buf, &new_state);
+   if (ret)
+           return -EINVAL;
+
+   amd_pstate_global_params.cpb_boost = !!new_state;
+
+   for_each_online_cpu(cpu) {
+
+           struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);

drivers/cpufreq/amd-pstate.c static ssize_t prefcore_show(struct device *dev,

Quoted 10 lines
drivers/cpufreq/amd-pstate.c +10 -0
+           struct amd_cpudata *cpudata = policy->driver_data;
+
+           if (!cpudata) {
+                   pr_err("cpudata is NULL\n");
+                   ret = -ENODATA;
+                   cpufreq_cpu_put(policy);
+                   goto err_exit;
+           }
+
+           amd_cpu_boost_update(cpudata,

amd_pstate_global_params.cpb_boost);

Quoted 32 lines
drivers/cpufreq/amd-pstate.c +10 -0
+           refresh_frequency_limits(policy);
+           cpufreq_cpu_put(policy);
+   }
+
+err_exit:
+   mutex_unlock(&amd_pstate_driver_lock);
+   return ret < 0 ? ret : count;
+}
+
 cpufreq_freq_attr_ro(amd_pstate_max_freq);
 cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
@@ -1218,6 +1313,7 @@
 cpufreq_freq_attr_rw(energy_performance_preference);
 cpufreq_freq_attr_ro(energy_performance_available_preferences);
 static DEVICE_ATTR_RW(status);
 static DEVICE_ATTR_RO(prefcore);
+static DEVICE_ATTR_RW(cpb_boost);
 
 static struct freq_attr *amd_pstate_attr[] = {

&amd_pstate_max_freq,

drivers/cpufreq/amd-pstate.c +1 -1
@@ -1242,6 +1338,7 @@ static struct freq_attr *amd_pstate_epp_attr[] =
 {  static struct attribute *pstate_global_attributes[] = {
    &dev_attr_status.attr,
    &dev_attr_prefcore.attr,
+   &dev_attr_cpb_boost.attr,
    NULL
 };
 
--

2.34.1

#10 lore raw

Re: [PATCH v4 4/7] cpufreq: amd-pstate: fix the MSR highest perf will be reset issue while cpb boost off

In reply to Perry Yuan

Hello Perry,

Quoted 7 lines · Perry Yuan

From: Perry Yuan <[email protected]>

Select the min perf to fix the highest perf value while update pstate CPPC request MSR register, here we need to limit the max perf value when CPU boost is disabled in case of that highest perf value in the MSR will be reset to original highest perf value which cause the BOOST control failed.

From the code in this patch, what you are trying to do is limit the max_perf value to the minimum of the highest_perf and nominal_perf when boost is disabled. A question : Why not unconditionally set the max_perf to the nominal_perf ?

--
Thanks and Regards
gautham.

Quoted 32 lines
---
 drivers/cpufreq/amd-pstate.c | 5 +++++
 1 file changed, 5 insertions(+)
drivers/cpufreq/amd-pstate.c +5 -0
index 0965fbf660dd..d7afbded6e3d 100644
@@ -440,6 +440,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 			      u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags)
 {
 	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
+	u32 nominal_perf = READ_ONCE(cpudata->nominal_perf);
 	u64 value = prev;
 
 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
@@ -459,6 +460,10 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
 	value &= ~AMD_CPPC_DES_PERF(~0L);
 	value |= AMD_CPPC_DES_PERF(des_perf);
 
+	/* limit the max perf when core performance boost feature is disabled */
+	if (!amd_pstate_global_params.cpb_boost)
+		max_perf = min_t(unsigned long, nominal_perf, max_perf);
+
 	value &= ~AMD_CPPC_MAX_PERF(~0L);
 	value |= AMD_CPPC_MAX_PERF(max_perf);
 
Signature · 1 line
2.34.1
#13 lore raw

Re: [PATCH v4 6/7] cpufreq: amd-pstate: remove legacy set_boost callback for passive mode

In reply to Perry Yuan

Hello Perry,

Quoted 2 lines · Perry Yuan

With new freqency boost interface supported, legacy boost control doesn't make sense any more which only support passive mode.

Why is the legacy boost control restricted only to the passive mode ?

Can we not add .set_boost to amd_pstate_set_boost in amd_pstate_epp_driver ?

--
Thanks and Regards
gautham.

Quoted 44 lines

so it can remove the legacy set_boost interface from amd-pstate driver in case of there is conflict with new boost control logic.

---
 drivers/cpufreq/amd-pstate.c | 1 -
 include/linux/amd-pstate.h   | 2 --
 2 files changed, 3 deletions(-)
drivers/cpufreq/amd-pstate.c +0 -1
index d7afbded6e3d..4a24db868cb1 100644
@@ -1689,7 +1689,6 @@ static struct cpufreq_driver amd_pstate_driver = {
 	.exit		= amd_pstate_cpu_exit,
 	.suspend	= amd_pstate_cpu_suspend,
 	.resume		= amd_pstate_cpu_resume,
-	.set_boost	= amd_pstate_set_boost,
 	.update_limits	= amd_pstate_update_limits,
 	.name		= "amd-pstate",
 	.attr		= amd_pstate_attr,
include/linux/amd-pstate.h +0 -2
index c6e2a97913de..7130b297c522 100644
@@ -56,7 +56,6 @@ struct amd_aperf_mperf {
  * @cur: Difference of Aperf/Mperf/tsc count between last and current sample
  * @prev: Last Aperf/Mperf/tsc count value read from register
  * @freq: current cpu frequency value
- * @boost_supported: check whether the Processor or SBIOS supports boost mode
  * @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.
@@ -93,7 +92,6 @@ struct amd_cpudata {
 	struct amd_aperf_mperf prev;
 
 	u64	freq;
-	bool	boost_supported;
 	bool	hw_prefcore;
 
 	/* EPP feature related attributes*/
Signature · 1 line
2.34.1
author reviewer
#14 lore raw

RE: [PATCH v4 6/7] cpufreq: amd-pstate: remove legacy set_boost callback for passive mode

[AMD Official Use Only - General]

Quoted 20 lines

-----Original Message-----
From: Shenoy, Gautham Ranjal <[email protected]>
Sent: Thursday, March 14, 2024 6:07 PM
To: Yuan, Perry <[email protected]>
Cc: [email protected]; Limonciello, Mario <[email protected]>; [email protected]; Huang, Ray <[email protected]>; Petkov, Borislav <[email protected]>; 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 v4 6/7] cpufreq: amd-pstate: remove legacy set_boost callback for passive mode

Hello Perry,

Quoted 2 lines · Perry Yuan

With new freqency boost interface supported, legacy boost control doesn't make sense any more which only support passive mode.

Quoted 8 lines

Why is the legacy boost control restricted only to the passive mode ?

Can we not add .set_boost to amd_pstate_set_boost in amd_pstate_epp_driver ?

--
Thanks and Regards
gautham.

The new interface is more meaningful to amd-pstate driver, I would like to put the control interface into unique directory like intel dose. There will be other interfaces to be added, put them into together is more reasonable to control and maintain.

Perry.

Quoted 49 lines
Quoted 4 lines

so it can remove the legacy set_boost interface from amd-pstate driver in case of there is conflict with new boost control logic.

Quoted 8 lines
---
 drivers/cpufreq/amd-pstate.c | 1 -
 include/linux/amd-pstate.h   | 2 --
 2 files changed, 3 deletions(-)
(quoted diff) +0 -0

b/drivers/cpufreq/amd-pstate.c index d7afbded6e3d..4a24db868cb1

100644

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

Quoted 3 lines
drivers/cpufreq/amd-pstate.c +0 -0
@@ -1689,7 +1689,6 @@ static struct cpufreq_driver amd_pstate_driver =

{

include/linux/amd-pstate.h struct amd_aperf_mperf { · line 56

Quoted 13 lines
drivers/cpufreq/amd-pstate.c +0 -1
    .exit           = amd_pstate_cpu_exit,
    .suspend        = amd_pstate_cpu_suspend,
    .resume         = amd_pstate_cpu_resume,
-   .set_boost      = amd_pstate_set_boost,
    .update_limits  = amd_pstate_update_limits,
    .name           = "amd-pstate",
    .attr           = amd_pstate_attr,
include/linux/amd-pstate.h +0 -0
index c6e2a97913de..7130b297c522 100644
@@ -56,7 +56,6 @@ struct amd_aperf_mperf {
  * @cur: Difference of Aperf/Mperf/tsc count between last and current

sample

include/linux/amd-pstate.h struct amd_aperf_mperf {

Quoted 3 lines
include/linux/amd-pstate.h +0 -1
  * @prev: Last Aperf/Mperf/tsc count value read from register
  * @freq: current cpu frequency value
- * @boost_supported: check whether the Processor or SBIOS supports

boost mode

Quoted 14 lines
include/linux/amd-pstate.h +0 -2
  * @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.
@@ -93,7 +92,6 @@ struct amd_cpudata {
    struct amd_aperf_mperf prev;
 
    u64     freq;
-   bool    boost_supported;
    bool    hw_prefcore;
 
    /* EPP feature related attributes*/
--

2.34.1