drm/ttm: remove ttm_tt_destroy_common v2

Move the functionality into ttm_tt_fini and ttm_bo_tt_destroy instead.

We don't need this any more since we removed the unbind from the destroy
code paths in the drivers.

Also add a warning to ttm_tt_fini() if we try to fini a still populated TT
object.

v2: instead of reverting the patch move the functionality to different
places.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210728130552.2074-5-christian.koenig@amd.com

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

@@ -1066,7 +1066,6 @@ static void amdgpu_ttm_backend_destroy(struct ttm_device *bdev,
 {
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
 
-	ttm_tt_destroy_common(bdev, ttm);
 	if (gtt->usertask)
 		put_task_struct(gtt->usertask);
 

drivers/gpu/drm/drm_gem_vram_helper.c

@@ -846,7 +846,6 @@ static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = {
 
 static void bo_driver_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *tt)
 {
-	ttm_tt_destroy_common(bdev, tt);
 	ttm_tt_fini(tt);
 	kfree(tt);
 }

drivers/gpu/drm/i915/gem/i915_gem_ttm.c

@@ -118,7 +118,6 @@ static void i915_ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 {
 	struct i915_ttm_tt *i915_tt = container_of(ttm, typeof(*i915_tt), ttm);
 
-	ttm_tt_destroy_common(bdev, ttm);
 	kfree(i915_tt);
 }
 

drivers/gpu/drm/nouveau/nouveau_bo.c

@@ -1292,7 +1292,6 @@ nouveau_ttm_tt_destroy(struct ttm_device *bdev,
 #if IS_ENABLED(CONFIG_AGP)
 	struct nouveau_drm *drm = nouveau_bdev(bdev);
 	if (drm->agp.bridge) {
-		ttm_tt_destroy_common(bdev, ttm);
 		ttm_agp_destroy(ttm);
 		return;
 	}

drivers/gpu/drm/nouveau/nouveau_sgdma.c

@@ -21,7 +21,6 @@ nouveau_sgdma_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 	struct nouveau_sgdma_be *nvbe = (struct nouveau_sgdma_be *)ttm;
 
 	if (ttm) {
-		ttm_tt_destroy_common(bdev, ttm);
 		ttm_tt_fini(&nvbe->ttm);
 		kfree(nvbe);
 	}

drivers/gpu/drm/qxl/qxl_ttm.c

@@ -101,7 +101,6 @@ int qxl_ttm_io_mem_reserve(struct ttm_device *bdev,
  */
 static void qxl_ttm_backend_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 {
-	ttm_tt_destroy_common(bdev, ttm);
 	ttm_tt_fini(ttm);
 	kfree(ttm);
 }

drivers/gpu/drm/radeon/radeon_ttm.c

@@ -488,7 +488,6 @@ static void radeon_ttm_backend_destroy(struct ttm_device *bdev, struct ttm_tt *t
 {
 	struct radeon_ttm_tt *gtt = (void *)ttm;
 
-	ttm_tt_destroy_common(bdev, ttm);
 	ttm_tt_fini(&gtt->ttm);
 	kfree(gtt);
 }
@@ -651,7 +650,6 @@ static void radeon_ttm_tt_destroy(struct ttm_device *bdev,
 	struct radeon_device *rdev = radeon_get_rdev(bdev);
 
 	if (rdev->flags & RADEON_IS_AGP) {
-		ttm_tt_destroy_common(bdev, ttm);
 		ttm_agp_destroy(ttm);
 		return;
 	}

drivers/gpu/drm/ttm/ttm_bo.c

@@ -1224,6 +1224,7 @@ void ttm_bo_tt_destroy(struct ttm_buffer_object *bo)
 	if (bo->ttm == NULL)
 		return;
 
+	ttm_tt_unpopulate(bo->bdev, bo->ttm);
 	ttm_tt_destroy(bo->bdev, bo->ttm);
 	bo->ttm = NULL;
 }

drivers/gpu/drm/ttm/ttm_tt.c

@@ -123,17 +123,6 @@ static int ttm_sg_tt_alloc_page_directory(struct ttm_tt *ttm)
 	return 0;
 }
 
-void ttm_tt_destroy_common(struct ttm_device *bdev, struct ttm_tt *ttm)
-{
-	ttm_tt_unpopulate(bdev, ttm);
-
-	if (ttm->swap_storage)
-		fput(ttm->swap_storage);
-
-	ttm->swap_storage = NULL;
-}
-EXPORT_SYMBOL(ttm_tt_destroy_common);
-
 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 {
 	bdev->funcs->ttm_tt_destroy(bdev, ttm);
@@ -168,6 +157,12 @@ EXPORT_SYMBOL(ttm_tt_init);
 
 void ttm_tt_fini(struct ttm_tt *ttm)
 {
+	WARN_ON(ttm->page_flags & TTM_PAGE_FLAG_PRIV_POPULATED);
+
+	if (ttm->swap_storage)
+		fput(ttm->swap_storage);
+	ttm->swap_storage = NULL;
+
 	if (ttm->pages)
 		kvfree(ttm->pages);
 	else

drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c

@@ -526,7 +526,6 @@ static void vmw_ttm_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 	struct vmw_ttm_tt *vmw_be =
 		container_of(ttm, struct vmw_ttm_tt, dma_ttm);
 
-	ttm_tt_destroy_common(bdev, ttm);
 	vmw_ttm_unmap_dma(vmw_be);
 	ttm_tt_fini(ttm);
 	if (vmw_be->mob)

include/drm/ttm/ttm_tt.h

@@ -134,13 +134,6 @@ void ttm_tt_fini(struct ttm_tt *ttm);
  */
 void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm);
 
-/**
- * ttm_tt_destroy_common:
- *
- * Called from driver to destroy common path.
- */
-void ttm_tt_destroy_common(struct ttm_device *bdev, struct ttm_tt *ttm);
-
 /**
  * ttm_tt_swapin:
  *