drm/xe/lrc: Reduce scope of empty lrc data

The only case in which new lrc data is created from scratch is when it's
called prior to recording the default lrc. There's no need to check for
NULL init_data since in that case the function already failed: just move
the allocation where it's needed.

Reviewed-by: Tvrtko Ursulin <[email protected]>
Reviewed-by: Matthew Brost <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Lucas De Marchi <[email protected]>

Author: lucasdemarchi

drivers/gpu/drm/xe/xe_lrc.c

@@ -1157,7 +1157,6 @@ static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe,
 	struct xe_tile *tile = gt_to_tile(gt);
 	struct xe_device *xe = gt_to_xe(gt);
 	struct iosys_map map;
-	void *init_data = NULL;
 	u32 arb_enable;
 	u32 bo_flags;
 	int err;
@@ -1195,25 +1194,26 @@ static int xe_lrc_init(struct xe_lrc *lrc, struct xe_hw_engine *hwe,
 	xe_hw_fence_ctx_init(&lrc->fence_ctx, hwe->gt,
 			     hwe->fence_irq, hwe->name);
 
-	if (!gt->default_lrc[hwe->class]) {
-		init_data = empty_lrc_data(hwe);
-		if (!init_data) {
-			err = -ENOMEM;
-			goto err_lrc_finish;
-		}
-	}
-
 	/*
 	 * Init Per-Process of HW status Page, LRC / context state to known
-	 * values
+	 * values. If there's already a primed default_lrc, just copy it, otherwise
+	 * it's the early submission to record the lrc: build a new empty one from
+	 * scratch.
 	 */
 	map = __xe_lrc_pphwsp_map(lrc);
-	if (!init_data) {
+	if (gt->default_lrc[hwe->class]) {
 		xe_map_memset(xe, &map, 0, 0, LRC_PPHWSP_SIZE);	/* PPHWSP */
 		xe_map_memcpy_to(xe, &map, LRC_PPHWSP_SIZE,
 				 gt->default_lrc[hwe->class] + LRC_PPHWSP_SIZE,
 				 lrc_size - LRC_PPHWSP_SIZE);
 	} else {
+		void *init_data = empty_lrc_data(hwe);
+
+		if (!init_data) {
+			err = -ENOMEM;
+			goto err_lrc_finish;
+		}
+
 		xe_map_memcpy_to(xe, &map, 0, init_data, lrc_size);
 		kfree(init_data);
 	}