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 <tvrtko.ursulin@igalia.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250710-lrc-refactors-v2-1-a5e2ca03f6bd@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_lrc.c b/drivers/gpu/drm/xe/xe_lrc.c
index 0769d759b558862e9c907aa6ea30874c57e61ed3..682c5b69fee8c6a3968a6560ec6a3ea2f6626da9 100644 (file)
--- a/drivers/gpu/drm/xe/xe_lrc.c
+++ b/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);
        }