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drm/xe/bo: Avoid creating a system resource when allocating a fresh VRAM bo

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When creating a new bo, on the first move the bo->resource is typically
NULL. Our move callback rejected that instructing TTM to create a system
resource. In addition a struct ttm_tt with a page-vector was created,
although not populated with pages. Similarly when the clearing of VRAM
was complete, the system resource was put on a ghost object and freed
using the TTM delayed destroy mechanism.

This is a lot of pointless work. So avoid creating the system resource and
instead change the code to cope with a NULL bo->resource.

v2:
- Add some code comments (Matthew Brost)
v3:
- Fix a dereference of old_mem which might be NULL.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230626181741.32820-3-thomas.hellstrom@linux.intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Thomas Hellström 2023-06-26 20:17:39 +02:00 committed by Rodrigo Vivi
parent bc2e0215de
commit 3439cc4661
1 changed files with 27 additions and 21 deletions
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48
drivers/gpu/drm/xe/xe_bo.c
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@ -479,7 +479,6 @@ static int xe_bo_trigger_rebind(struct xe_device *xe, struct xe_bo *bo,
* to unconditionally call unmap_attachment() when moving out to system.
*/
static int xe_bo_move_dmabuf(struct ttm_buffer_object *ttm_bo,
struct ttm_resource *old_res,
struct ttm_resource *new_res)
{
struct dma_buf_attachment *attach = ttm_bo->base.import_attach;
@ -564,6 +563,7 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
struct xe_device *xe = ttm_to_xe_device(ttm_bo->bdev);
struct xe_bo *bo = ttm_to_xe_bo(ttm_bo);
struct ttm_resource *old_mem = ttm_bo->resource;
u32 old_mem_type = old_mem ? old_mem->mem_type : XE_PL_SYSTEM;
struct ttm_tt *ttm = ttm_bo->ttm;
struct xe_tile *tile = NULL;
struct dma_fence *fence;
@ -572,35 +572,29 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
bool needs_clear;
int ret = 0;
if (!old_mem) {
if (new_mem->mem_type != TTM_PL_SYSTEM) {
hop->mem_type = TTM_PL_SYSTEM;
hop->flags = TTM_PL_FLAG_TEMPORARY;
ret = -EMULTIHOP;
goto out;
}
/* Bo creation path, moving to system or TT. No clearing required. */
if (!old_mem && ttm) {
ttm_bo_move_null(ttm_bo, new_mem);
goto out;
return 0;
}
if (ttm_bo->type == ttm_bo_type_sg) {
ret = xe_bo_move_notify(bo, ctx);
if (!ret)
ret = xe_bo_move_dmabuf(ttm_bo, old_mem, new_mem);
ret = xe_bo_move_dmabuf(ttm_bo, new_mem);
goto out;
}
tt_has_data = ttm && (ttm_tt_is_populated(ttm) ||
(ttm->page_flags & TTM_TT_FLAG_SWAPPED));
move_lacks_source = !resource_is_vram(old_mem) && !tt_has_data;
move_lacks_source = !mem_type_is_vram(old_mem_type) && !tt_has_data;
needs_clear = (ttm && ttm->page_flags & TTM_TT_FLAG_ZERO_ALLOC) ||
(!ttm && ttm_bo->type == ttm_bo_type_device);
if ((move_lacks_source && !needs_clear) ||
(old_mem->mem_type == XE_PL_SYSTEM &&
(old_mem_type == XE_PL_SYSTEM &&
new_mem->mem_type == XE_PL_TT)) {
ttm_bo_move_null(ttm_bo, new_mem);
goto out;
@ -610,7 +604,7 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
* Failed multi-hop where the old_mem is still marked as
* TTM_PL_FLAG_TEMPORARY, should just be a dummy move.
*/
if (old_mem->mem_type == XE_PL_TT &&
if (old_mem_type == XE_PL_TT &&
new_mem->mem_type == XE_PL_TT) {
ttm_bo_move_null(ttm_bo, new_mem);
goto out;
@ -622,7 +616,7 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
goto out;
}
if (old_mem->mem_type == XE_PL_TT &&
if (old_mem_type == XE_PL_TT &&
new_mem->mem_type == XE_PL_SYSTEM) {
long timeout = dma_resv_wait_timeout(ttm_bo->base.resv,
DMA_RESV_USAGE_BOOKKEEP,
@ -637,8 +631,8 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
}
if (!move_lacks_source &&
((old_mem->mem_type == XE_PL_SYSTEM && resource_is_vram(new_mem)) ||
(resource_is_vram(old_mem) &&
((old_mem_type == XE_PL_SYSTEM && resource_is_vram(new_mem)) ||
(mem_type_is_vram(old_mem_type) &&
new_mem->mem_type == XE_PL_SYSTEM))) {
hop->fpfn = 0;
hop->lpfn = 0;
@ -652,8 +646,8 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
tile = bo->tile;
else if (resource_is_vram(new_mem))
tile = mem_type_to_tile(xe, new_mem->mem_type);
else if (resource_is_vram(old_mem))
tile = mem_type_to_tile(xe, old_mem->mem_type);
else if (mem_type_is_vram(old_mem_type))
tile = mem_type_to_tile(xe, old_mem_type);
XE_BUG_ON(!tile);
XE_BUG_ON(!tile->migrate);
@ -703,8 +697,20 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
xe_device_mem_access_put(xe);
goto out;
}
ret = ttm_bo_move_accel_cleanup(ttm_bo, fence, evict, true,
new_mem);
if (!move_lacks_source) {
ret = ttm_bo_move_accel_cleanup(ttm_bo, fence, evict,
true, new_mem);
} else {
/*
* ttm_bo_move_accel_cleanup() may blow up if
* bo->resource == NULL, so just attach the
* fence and set the new resource.
*/
dma_resv_add_fence(ttm_bo->base.resv, fence,
DMA_RESV_USAGE_KERNEL);
ttm_bo_move_null(ttm_bo, new_mem);
}
dma_fence_put(fence);
}