From b374d82dca4721c534eb940b599dd4d45ba3a18f Mon Sep 17 00:00:00 2001 From: Tom St Denis Date: Wed, 20 Jun 2018 07:55:39 -0400 Subject: [PATCH] drm/amd/amdgpu: Add a GPU_LOAD entry to sysfs (v3) This adds what should be a stable interface to read GPU load from userspace. (v2): Fix comments and name of file per recommendations. (v3): Add chapter to amdgpu.rst as well. Signed-off-by: Tom St Denis Acked-by: Slava Abramov Reviewed-by: Alex Deucher Signed-off-by: Alex Deucher --- Documentation/gpu/amdgpu.rst | 5 ++++ drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c | 40 ++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) diff --git a/Documentation/gpu/amdgpu.rst b/Documentation/gpu/amdgpu.rst index e52d0ce186fe..765c2a32938f 100644 --- a/Documentation/gpu/amdgpu.rst +++ b/Documentation/gpu/amdgpu.rst @@ -115,3 +115,8 @@ pp_power_profile_mode .. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c :doc: pp_power_profile_mode +busy_percent +~~~~~~~~~~~~ + +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c + :doc: busy_percent diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c index 113edffb5960..fdb399821915 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c @@ -918,6 +918,36 @@ fail: return -EINVAL; } +/** + * DOC: busy_percent + * + * The amdgpu driver provides a sysfs API for reading how busy the GPU + * is as a percentage. The file gpu_busy_percent is used for this. + * The SMU firmware computes a percentage of load based on the + * aggregate activity level in the IP cores. + */ +static ssize_t amdgpu_get_busy_percent(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct drm_device *ddev = dev_get_drvdata(dev); + struct amdgpu_device *adev = ddev->dev_private; + int r, value, size = sizeof(value); + + /* sanity check PP is enabled */ + if (!(adev->powerplay.pp_funcs && + adev->powerplay.pp_funcs->read_sensor)) + return -EINVAL; + + /* read the IP busy sensor */ + r = amdgpu_dpm_read_sensor(adev, AMDGPU_PP_SENSOR_GPU_LOAD, + (void *)&value, &size); + if (r) + return r; + + return snprintf(buf, PAGE_SIZE, "%d\n", value); +} + static DEVICE_ATTR(power_dpm_state, S_IRUGO | S_IWUSR, amdgpu_get_dpm_state, amdgpu_set_dpm_state); static DEVICE_ATTR(power_dpm_force_performance_level, S_IRUGO | S_IWUSR, amdgpu_get_dpm_forced_performance_level, @@ -951,6 +981,8 @@ static DEVICE_ATTR(pp_power_profile_mode, S_IRUGO | S_IWUSR, static DEVICE_ATTR(pp_od_clk_voltage, S_IRUGO | S_IWUSR, amdgpu_get_pp_od_clk_voltage, amdgpu_set_pp_od_clk_voltage); +static DEVICE_ATTR(gpu_busy_percent, S_IRUGO, + amdgpu_get_busy_percent, NULL); static ssize_t amdgpu_hwmon_show_temp(struct device *dev, struct device_attribute *attr, @@ -1854,6 +1886,13 @@ int amdgpu_pm_sysfs_init(struct amdgpu_device *adev) "pp_od_clk_voltage\n"); return ret; } + ret = device_create_file(adev->dev, + &dev_attr_gpu_busy_percent); + if (ret) { + DRM_ERROR("failed to create device file " + "gpu_busy_level\n"); + return ret; + } ret = amdgpu_debugfs_pm_init(adev); if (ret) { DRM_ERROR("Failed to register debugfs file for dpm!\n"); @@ -1889,6 +1928,7 @@ void amdgpu_pm_sysfs_fini(struct amdgpu_device *adev) &dev_attr_pp_power_profile_mode); device_remove_file(adev->dev, &dev_attr_pp_od_clk_voltage); + device_remove_file(adev->dev, &dev_attr_gpu_busy_percent); } void amdgpu_pm_compute_clocks(struct amdgpu_device *adev)