drm/amdgpu: Introduce functions for vram physical addr calculation

Add one function to calculate BO's GPU physical address.
And another function to calculate BO's CPU physical address.

v2: Use functions vs macros (Christian)
    Use more proper function names (Christian)
Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Suggested-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -685,3 +685,39 @@ void amdgpu_gmc_init_pdb0(struct amdgpu_device *adev)
 	/* Requires gart_ptb_gpu_pa to be 4K aligned */
 	amdgpu_gmc_set_pte_pde(adev, adev->gmc.ptr_pdb0, i, gart_ptb_gpu_pa, flags);
 }
+
+/**
+ * amdgpu_gmc_vram_mc2pa - calculate vram buffer's physical address from MC
+ * address
+ *
+ * @adev: amdgpu_device pointer
+ * @mc_addr: MC address of buffer
+ */
+uint64_t amdgpu_gmc_vram_mc2pa(struct amdgpu_device *adev, uint64_t mc_addr)
+{
+	return mc_addr - adev->gmc.vram_start + adev->vm_manager.vram_base_offset;
+}
+
+/**
+ * amdgpu_gmc_vram_pa - calculate vram buffer object's physical address from
+ * GPU's view
+ *
+ * @adev: amdgpu_device pointer
+ * @bo: amdgpu buffer object
+ */
+uint64_t amdgpu_gmc_vram_pa(struct amdgpu_device *adev, struct amdgpu_bo *bo)
+{
+	return amdgpu_gmc_vram_mc2pa(adev, amdgpu_bo_gpu_offset(bo));
+}
+
+/**
+ * amdgpu_gmc_vram_cpu_pa - calculate vram buffer object's physical address
+ * from CPU's view
+ *
+ * @adev: amdgpu_device pointer
+ * @bo: amdgpu buffer object
+ */
+uint64_t amdgpu_gmc_vram_cpu_pa(struct amdgpu_device *adev, struct amdgpu_bo *bo)
+{
+	return amdgpu_bo_gpu_offset(bo) - adev->gmc.vram_start + adev->gmc.aper_base;
+}

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

@@ -341,4 +341,7 @@ amdgpu_gmc_set_vm_fault_masks(struct amdgpu_device *adev, int hub_type,
 void amdgpu_gmc_get_vbios_allocations(struct amdgpu_device *adev);
 
 void amdgpu_gmc_init_pdb0(struct amdgpu_device *adev);
+uint64_t amdgpu_gmc_vram_mc2pa(struct amdgpu_device *adev, uint64_t mc_addr);
+uint64_t amdgpu_gmc_vram_pa(struct amdgpu_device *adev, struct amdgpu_bo *bo);
+uint64_t amdgpu_gmc_vram_cpu_pa(struct amdgpu_device *adev, struct amdgpu_bo *bo);
 #endif