drm/amdgpu/gmc9: set mc vm fb offset for raven

APU fb offset is set by sbios, which is different with DGPU.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Ken Wang <Qingqing.Wang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.c

@@ -31,6 +31,11 @@
 
 #include "soc15_common.h"
 
+u64 gfxhub_v1_0_get_mc_fb_offset(struct amdgpu_device *adev)
+{
+	return (u64)RREG32(SOC15_REG_OFFSET(GC, 0, mmMC_VM_FB_OFFSET)) << 24;
+}
+
 int gfxhub_v1_0_gart_enable(struct amdgpu_device *adev)
 {
 	u32 tmp;

drivers/gpu/drm/amd/amdgpu/gfxhub_v1_0.h

@@ -28,7 +28,7 @@ int gfxhub_v1_0_gart_enable(struct amdgpu_device *adev);
 void gfxhub_v1_0_gart_disable(struct amdgpu_device *adev);
 void gfxhub_v1_0_set_fault_enable_default(struct amdgpu_device *adev,
 					  bool value);
-
+u64 gfxhub_v1_0_get_mc_fb_offset(struct amdgpu_device *adev);
 extern const struct amd_ip_funcs gfxhub_v1_0_ip_funcs;
 extern const struct amdgpu_ip_block_version gfxhub_v1_0_ip_block;
 

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -548,7 +548,9 @@ static int gmc_v9_0_vm_init(struct amdgpu_device *adev)
 	amdgpu_vm_manager_init(adev);
 
 	/* base offset of vram pages */
-	/*XXX This value is not zero for APU*/
+	if (adev->flags & AMD_IS_APU)
+		adev->vm_manager.vram_base_offset = gfxhub_v1_0_get_mc_fb_offset(adev);
+	else
 		adev->vm_manager.vram_base_offset = 0;
 
 	return 0;