drm/xe: Adjust batchbuffer space warning when creating a job

We should WARN (not BUG) when creating a job if the batchbuffer does not
have sufficient space and padding.  The hardware prefetch requirements
should also be considered.

Link: https://lore.kernel.org/r/20230329173334.4015124-3-matthew.d.roper@intel.comSigned-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_bb.c

@@ -63,10 +63,10 @@ __xe_bb_create_job(struct xe_engine *kernel_eng, struct xe_bb *bb, u64 *addr)
 {
 	u32 size = drm_suballoc_size(bb->bo);
 
-	XE_BUG_ON((bb->len * 4 + 1) > size);
-
 	bb->cs[bb->len++] = MI_BATCH_BUFFER_END;
 
+	WARN_ON(bb->len * 4 + bb_prefetch(kernel_eng->gt) > size);
+
 	xe_sa_bo_flush_write(bb->bo);
 
 	return xe_sched_job_create(kernel_eng, addr);