drm/amdgpu: add helpers for baco entry and exit

BACO - Bus Active, Chip Off

Will be used for runtime pm.  Entry will enter the BACO
state (chip off).  Exit will exit the BACO state (chip on).
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -1144,6 +1144,8 @@ bool amdgpu_device_supports_boco(struct drm_device *dev);
 bool amdgpu_device_supports_baco(struct drm_device *dev);
 bool amdgpu_device_is_peer_accessible(struct amdgpu_device *adev,
 				      struct amdgpu_device *peer_adev);
+int amdgpu_device_baco_enter(struct drm_device *dev);
+int amdgpu_device_baco_exit(struct drm_device *dev);
 
 /* atpx handler */
 #if defined(CONFIG_VGA_SWITCHEROO)

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -4296,3 +4296,64 @@ static void amdgpu_device_get_pcie_info(struct amdgpu_device *adev)
 	}
 }
 
+int amdgpu_device_baco_enter(struct drm_device *dev)
+{
+	struct amdgpu_device *adev = dev->dev_private;
+
+	if (!amdgpu_device_supports_baco(adev->ddev))
+		return -ENOTSUPP;
+
+	if (is_support_sw_smu(adev)) {
+		struct smu_context *smu = &adev->smu;
+		int ret;
+
+		ret = smu_baco_enter(smu);
+		if (ret)
+			return ret;
+
+		return 0;
+	} else {
+		void *pp_handle = adev->powerplay.pp_handle;
+		const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
+
+		if (!pp_funcs ||!pp_funcs->get_asic_baco_state ||!pp_funcs->set_asic_baco_state)
+			return -ENOENT;
+
+		/* enter BACO state */
+		if (pp_funcs->set_asic_baco_state(pp_handle, 1))
+			return -EIO;
+
+		return 0;
+	}
+}
+
+int amdgpu_device_baco_exit(struct drm_device *dev)
+{
+	struct amdgpu_device *adev = dev->dev_private;
+
+	if (!amdgpu_device_supports_baco(adev->ddev))
+		return -ENOTSUPP;
+
+	if (is_support_sw_smu(adev)) {
+		struct smu_context *smu = &adev->smu;
+		int ret;
+
+		ret = smu_baco_exit(smu);
+		if (ret)
+			return ret;
+
+		return 0;
+	} else {
+		void *pp_handle = adev->powerplay.pp_handle;
+		const struct amd_pm_funcs *pp_funcs = adev->powerplay.pp_funcs;
+
+		if (!pp_funcs ||!pp_funcs->get_asic_baco_state ||!pp_funcs->set_asic_baco_state)
+			return -ENOENT;
+
+		/* exit BACO state */
+		if (pp_funcs->set_asic_baco_state(pp_handle, 0))
+			return -EIO;
+
+		return 0;
+	}
+}