drm/amdgpu: added a sysfs interface for thermal throttling

added a sysfs interface for thermal throttling, then userspace
can get/update thermal limit
Signed-off-by: Kun Liu <Kun.Liu2@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/include/kgd_pp_interface.h

@@ -331,6 +331,8 @@ struct amd_pm_funcs {
 	int (*get_mclk_od)(void *handle);
 	int (*set_mclk_od)(void *handle, uint32_t value);
 	int (*read_sensor)(void *handle, int idx, void *value, int *size);
+	int (*get_apu_thermal_limit)(void *handle, uint32_t *limit);
+	int (*set_apu_thermal_limit)(void *handle, uint32_t limit);
 	enum amd_dpm_forced_level (*get_performance_level)(void *handle);
 	enum amd_pm_state_type (*get_current_power_state)(void *handle);
 	int (*get_fan_speed_rpm)(void *handle, uint32_t *rpm);

drivers/gpu/drm/amd/pm/amdgpu_dpm.c

@@ -456,6 +456,34 @@ int amdgpu_dpm_read_sensor(struct amdgpu_device *adev, enum amd_pp_sensors senso
 	return ret;
 }
 
+int amdgpu_dpm_get_apu_thermal_limit(struct amdgpu_device *adev, uint32_t *limit)
+{
+	const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
+	int ret = -EINVAL;
+
+	if (pp_funcs && pp_funcs->get_apu_thermal_limit) {
+		mutex_lock(&adev->pm.mutex);
+		ret = pp_funcs->get_apu_thermal_limit(adev->powerplay.pp_handle, limit);
+		mutex_unlock(&adev->pm.mutex);
+	}
+
+	return ret;
+}
+
+int amdgpu_dpm_set_apu_thermal_limit(struct amdgpu_device *adev, uint32_t limit)
+{
+	const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
+	int ret = -EINVAL;
+
+	if (pp_funcs && pp_funcs->set_apu_thermal_limit) {
+		mutex_lock(&adev->pm.mutex);
+		ret = pp_funcs->set_apu_thermal_limit(adev->powerplay.pp_handle, limit);
+		mutex_unlock(&adev->pm.mutex);
+	}
+
+	return ret;
+}
+
 void amdgpu_dpm_compute_clocks(struct amdgpu_device *adev)
 {
 	const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;

drivers/gpu/drm/amd/pm/amdgpu_pm.c

@@ -1685,6 +1685,82 @@ static ssize_t amdgpu_set_thermal_throttling_logging(struct device *dev,
 	return count;
 }
 
+/**
+ * DOC: apu_thermal_cap
+ *
+ * The amdgpu driver provides a sysfs API for retrieving/updating thermal
+ * limit temperature in millidegrees Celsius
+ *
+ * Reading back the file shows you core limit value
+ *
+ * Writing an integer to the file, sets a new thermal limit. The value
+ * should be between 0 and 100. If the value is less than 0 or greater
+ * than 100, then the write request will be ignored.
+ */
+static ssize_t amdgpu_get_apu_thermal_cap(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	int ret, size;
+	u32 limit;
+	struct drm_device *ddev = dev_get_drvdata(dev);
+	struct amdgpu_device *adev = drm_to_adev(ddev);
+
+	ret = pm_runtime_get_sync(ddev->dev);
+	if (ret < 0) {
+		pm_runtime_put_autosuspend(ddev->dev);
+		return ret;
+	}
+
+	ret = amdgpu_dpm_get_apu_thermal_limit(adev, &limit);
+	if (!ret)
+		size = sysfs_emit(buf, "%u\n", limit);
+	else
+		size = sysfs_emit(buf, "failed to get thermal limit\n");
+
+	pm_runtime_mark_last_busy(ddev->dev);
+	pm_runtime_put_autosuspend(ddev->dev);
+
+	return size;
+}
+
+static ssize_t amdgpu_set_apu_thermal_cap(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf,
+					 size_t count)
+{
+	int ret;
+	u32 value;
+	struct drm_device *ddev = dev_get_drvdata(dev);
+	struct amdgpu_device *adev = drm_to_adev(ddev);
+
+	ret = kstrtou32(buf, 10, &value);
+	if (ret)
+		return ret;
+
+	if (value < 0 || value > 100) {
+		dev_err(dev, "Invalid argument !\n");
+		return -EINVAL;
+	}
+
+	ret = pm_runtime_get_sync(ddev->dev);
+	if (ret < 0) {
+		pm_runtime_put_autosuspend(ddev->dev);
+		return ret;
+	}
+
+	ret = amdgpu_dpm_set_apu_thermal_limit(adev, value);
+	if (ret) {
+		dev_err(dev, "failed to update thermal limit\n");
+		return ret;
+	}
+
+	pm_runtime_mark_last_busy(ddev->dev);
+	pm_runtime_put_autosuspend(ddev->dev);
+
+	return count;
+}
+
 /**
  * DOC: gpu_metrics
  *
@@ -1937,6 +2013,7 @@ static struct amdgpu_device_attr amdgpu_device_attrs[] = {
 	AMDGPU_DEVICE_ATTR_RW(pp_features,				ATTR_FLAG_BASIC|ATTR_FLAG_ONEVF),
 	AMDGPU_DEVICE_ATTR_RO(unique_id,				ATTR_FLAG_BASIC|ATTR_FLAG_ONEVF),
 	AMDGPU_DEVICE_ATTR_RW(thermal_throttling_logging,		ATTR_FLAG_BASIC|ATTR_FLAG_ONEVF),
+	AMDGPU_DEVICE_ATTR_RW(apu_thermal_cap,				ATTR_FLAG_BASIC|ATTR_FLAG_ONEVF),
 	AMDGPU_DEVICE_ATTR_RO(gpu_metrics,				ATTR_FLAG_BASIC|ATTR_FLAG_ONEVF),
 	AMDGPU_DEVICE_ATTR_RO(smartshift_apu_power,			ATTR_FLAG_BASIC,
 			      .attr_update = ss_power_attr_update),

drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h

@@ -369,6 +369,9 @@ struct amdgpu_pm {
 int amdgpu_dpm_read_sensor(struct amdgpu_device *adev, enum amd_pp_sensors sensor,
 			   void *data, uint32_t *size);
 
+int amdgpu_dpm_get_apu_thermal_limit(struct amdgpu_device *adev, uint32_t *limit);
+int amdgpu_dpm_set_apu_thermal_limit(struct amdgpu_device *adev, uint32_t limit);
+
 int amdgpu_dpm_set_powergating_by_smu(struct amdgpu_device *adev,
 				      uint32_t block_type, bool gate);
 

drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c

@@ -2532,6 +2532,28 @@ static int smu_read_sensor(void *handle,
 	return ret;
 }
 
+static int smu_get_apu_thermal_limit(void *handle, uint32_t *limit)
+{
+	int ret = -EINVAL;
+	struct smu_context *smu = handle;
+
+	if (smu->ppt_funcs && smu->ppt_funcs->get_apu_thermal_limit)
+		ret = smu->ppt_funcs->get_apu_thermal_limit(smu, limit);
+
+	return ret;
+}
+
+static int smu_set_apu_thermal_limit(void *handle, uint32_t limit)
+{
+	int ret = -EINVAL;
+	struct smu_context *smu = handle;
+
+	if (smu->ppt_funcs && smu->ppt_funcs->set_apu_thermal_limit)
+		ret = smu->ppt_funcs->set_apu_thermal_limit(smu, limit);
+
+	return ret;
+}
+
 static int smu_get_power_profile_mode(void *handle, char *buf)
 {
 	struct smu_context *smu = handle;
@@ -3033,6 +3055,8 @@ static const struct amd_pm_funcs swsmu_pm_funcs = {
 	.emit_clock_levels       = smu_emit_ppclk_levels,
 	.force_performance_level = smu_force_performance_level,
 	.read_sensor             = smu_read_sensor,
+	.get_apu_thermal_limit       = smu_get_apu_thermal_limit,
+	.set_apu_thermal_limit       = smu_set_apu_thermal_limit,
 	.get_performance_level   = smu_get_performance_level,
 	.get_current_power_state = smu_get_current_power_state,
 	.get_fan_speed_rpm       = smu_get_fan_speed_rpm,

drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h

@@ -721,6 +721,18 @@ struct pptable_funcs {
 	int (*read_sensor)(struct smu_context *smu, enum amd_pp_sensors sensor,
 			   void *data, uint32_t *size);
 
+	/**
+	 * @get_apu_thermal_limit: get apu core limit from smu
+	 * &limit: current limit temperature in millidegrees Celsius
+	 */
+	int (*get_apu_thermal_limit)(struct smu_context *smu, uint32_t *limit);
+
+	/**
+	 * @set_apu_thermal_limit: update all controllers with new limit
+	 * &limit: limit temperature to be setted, in millidegrees Celsius
+	 */
+	int (*set_apu_thermal_limit)(struct smu_context *smu, uint32_t limit);
+
 	/**
 	 * @pre_display_config_changed: Prepare GPU for a display configuration
 	 *                              change.