[PATCH] drm/amd: Add a sysfs file to detect whether a GPU is an APU

[Mario Limonciello <superm1@kernel.org>]

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

In order to discover whether a GPU is part of a dGPU or APU userspace has
to do some mental gymnastics or heuristics.  Add a sysfs file that clearly
indicates to userspace.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/gpu/drm/amd/pm/amdgpu_pm.c     | 16 ++++++++++++++++
 drivers/gpu/drm/amd/pm/inc/amdgpu_pm.h |  1 +
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
index edd9895b46c02..4e4c77488e334 100644
--- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
@@ -945,6 +945,21 @@ static ssize_t amdgpu_get_pp_features(struct device *dev,
 	return size;
 }
 
+/**
+ * DOC: apu
+ *
+ * Represents whether GPU is on a dGPU (0) or APU (1)
+ */
+static ssize_t amdgpu_get_apu(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	struct drm_device *ddev = dev_get_drvdata(dev);
+	struct amdgpu_device *adev = drm_to_adev(ddev);
+
+	return sysfs_emit(buf, "%d\n", adev->flags & AMD_IS_APU ? 1 : 0);
+}
+
 /**
  * DOC: pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie
  *
@@ -2287,6 +2302,7 @@ static struct amdgpu_device_attr amdgpu_device_attrs[] = {
 			      .attr_update = ss_bias_attr_update),
 	AMDGPU_DEVICE_ATTR_RO(pm_metrics,				ATTR_FLAG_BASIC,
 			      .attr_update = amdgpu_pm_metrics_attr_update),
+	AMDGPU_DEVICE_ATTR_RO(apu,					ATTR_FLAG_BASIC),
 };
 
 static int default_attr_update(struct amdgpu_device *adev, struct amdgpu_device_attr *attr,
diff --git a/drivers/gpu/drm/amd/pm/inc/amdgpu_pm.h b/drivers/gpu/drm/amd/pm/inc/amdgpu_pm.h
index c12ced32f7808..ffd008c1e6ec2 100644
--- a/drivers/gpu/drm/amd/pm/inc/amdgpu_pm.h
+++ b/drivers/gpu/drm/amd/pm/inc/amdgpu_pm.h
@@ -78,6 +78,7 @@ enum amdgpu_device_attr_id {
 	device_attr_id__smartshift_dgpu_power,
 	device_attr_id__smartshift_bias,
 	device_attr_id__pm_metrics,
+	device_attr_id__apu,
 	device_attr_id__count,
 };
 
-- 
2.43.0