drm/ttm: init mem->bus in common code.

The drivers all do the same thing here.

Reviewed-by: Christian König <christian.koenig@amd.com> for both.
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200811074658.58309-1-airlied@gmail.com

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

@@ -752,12 +752,6 @@ static int amdgpu_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_reso
 	struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
 	struct drm_mm_node *mm_node = mem->mm_node;
 
-	mem->bus.addr = NULL;
-	mem->bus.offset = 0;
-	mem->bus.size = mem->num_pages << PAGE_SHIFT;
-	mem->bus.base = 0;
-	mem->bus.is_iomem = false;
-
 	switch (mem->mem_type) {
 	case TTM_PL_SYSTEM:
 		/* system memory */

drivers/gpu/drm/drm_gem_vram_helper.c

@@ -1038,14 +1038,8 @@ static int bo_driver_io_mem_reserve(struct ttm_bo_device *bdev,
 {
 	struct drm_vram_mm *vmm = drm_vram_mm_of_bdev(bdev);
 
-	mem->bus.addr = NULL;
-	mem->bus.size = mem->num_pages << PAGE_SHIFT;
-
 	switch (mem->mem_type) {
 	case TTM_PL_SYSTEM:	/* nothing to do */
-		mem->bus.offset = 0;
-		mem->bus.base = 0;
-		mem->bus.is_iomem = false;
 		break;
 	case TTM_PL_VRAM:
 		mem->bus.offset = mem->start << PAGE_SHIFT;

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -1025,12 +1025,6 @@ nouveau_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_resource *reg)
 	struct nvkm_device *device = nvxx_device(&drm->client.device);
 	struct nouveau_mem *mem = nouveau_mem(reg);
 
-	reg->bus.addr = NULL;
-	reg->bus.offset = 0;
-	reg->bus.size = reg->num_pages << PAGE_SHIFT;
-	reg->bus.base = 0;
-	reg->bus.is_iomem = false;
-
 	switch (reg->mem_type) {
 	case TTM_PL_SYSTEM:
 		/* System memory */

drivers/gpu/drm/qxl/qxl_ttm.c

@@ -75,12 +75,6 @@ int qxl_ttm_io_mem_reserve(struct ttm_bo_device *bdev,
 {
 	struct qxl_device *qdev = qxl_get_qdev(bdev);
 
-	mem->bus.addr = NULL;
-	mem->bus.offset = 0;
-	mem->bus.size = mem->num_pages << PAGE_SHIFT;
-	mem->bus.base = 0;
-	mem->bus.is_iomem = false;
-
 	switch (mem->mem_type) {
 	case TTM_PL_SYSTEM:
 		/* system memory */

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -363,12 +363,6 @@ static int radeon_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_reso
 {
 	struct radeon_device *rdev = radeon_get_rdev(bdev);
 
-	mem->bus.addr = NULL;
-	mem->bus.offset = 0;
-	mem->bus.size = mem->num_pages << PAGE_SHIFT;
-	mem->bus.base = 0;
-	mem->bus.is_iomem = false;
-
 	switch (mem->mem_type) {
 	case TTM_PL_SYSTEM:
 		/* system memory */

drivers/gpu/drm/ttm/ttm_bo_util.c

@@ -138,6 +138,11 @@ int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
 	if (!bdev->driver->io_mem_reserve)
 		return 0;
 
+	mem->bus.addr = NULL;
+	mem->bus.offset = 0;
+	mem->bus.size = mem->num_pages << PAGE_SHIFT;
+	mem->bus.base = 0;
+	mem->bus.is_iomem = false;
 retry:
 	ret = bdev->driver->io_mem_reserve(bdev, mem);
 	if (ret == -ENOSPC) {

drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c

@@ -715,12 +715,6 @@ static int vmw_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_resourc
 {
 	struct vmw_private *dev_priv = container_of(bdev, struct vmw_private, bdev);
 
-	mem->bus.addr = NULL;
-	mem->bus.is_iomem = false;
-	mem->bus.offset = 0;
-	mem->bus.size = mem->num_pages << PAGE_SHIFT;
-	mem->bus.base = 0;
-
 	switch (mem->mem_type) {
 	case TTM_PL_SYSTEM:
 	case VMW_PL_GMR: