From: Matthew Auld <matthew.auld@intel.com>
Date: Fri, 29 Aug 2025 16:47:16 +0000 (+0100)
Subject: drm/xe: improve dma-resv handling for backup object
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=edb1745fc618ba8ef63a45ce3ae60de1bdf29231;p=users%2Fhch%2Fmisc.git

drm/xe: improve dma-resv handling for backup object

Since the dma-resv is shared we don't need to reserve and add a fence
slot fence twice, plus no need to loop through the dependencies.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://lore.kernel.org/r/20250829164715.720735-2-matthew.auld@intel.com
---

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 4faf15d5fa6d..49911247f6cb 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -1260,14 +1260,11 @@ int xe_bo_evict_pinned(struct xe_bo *bo)
 		else
 			migrate = mem_type_to_migrate(xe, bo->ttm.resource->mem_type);
 
+		xe_assert(xe, bo->ttm.base.resv == backup->ttm.base.resv);
 		ret = dma_resv_reserve_fences(bo->ttm.base.resv, 1);
 		if (ret)
 			goto out_backup;
 
-		ret = dma_resv_reserve_fences(backup->ttm.base.resv, 1);
-		if (ret)
-			goto out_backup;
-
 		fence = xe_migrate_copy(migrate, bo, backup, bo->ttm.resource,
 					backup->ttm.resource, false);
 		if (IS_ERR(fence)) {
@@ -1277,8 +1274,6 @@ int xe_bo_evict_pinned(struct xe_bo *bo)
 
 		dma_resv_add_fence(bo->ttm.base.resv, fence,
 				   DMA_RESV_USAGE_KERNEL);
-		dma_resv_add_fence(backup->ttm.base.resv, fence,
-				   DMA_RESV_USAGE_KERNEL);
 		dma_fence_put(fence);
 	} else {
 		ret = xe_bo_vmap(backup);
@@ -1356,10 +1351,6 @@ int xe_bo_restore_pinned(struct xe_bo *bo)
 		if (ret)
 			goto out_unlock_bo;
 
-		ret = dma_resv_reserve_fences(backup->ttm.base.resv, 1);
-		if (ret)
-			goto out_unlock_bo;
-
 		fence = xe_migrate_copy(migrate, backup, bo,
 					backup->ttm.resource, bo->ttm.resource,
 					false);
@@ -1370,8 +1361,6 @@ int xe_bo_restore_pinned(struct xe_bo *bo)
 
 		dma_resv_add_fence(bo->ttm.base.resv, fence,
 				   DMA_RESV_USAGE_KERNEL);
-		dma_resv_add_fence(backup->ttm.base.resv, fence,
-				   DMA_RESV_USAGE_KERNEL);
 		dma_fence_put(fence);
 	} else {
 		ret = xe_bo_vmap(backup);
diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
index 9643442ef101..861d9d0633d1 100644
--- a/drivers/gpu/drm/xe/xe_migrate.c
+++ b/drivers/gpu/drm/xe/xe_migrate.c
@@ -908,7 +908,7 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
 		if (!fence) {
 			err = xe_sched_job_add_deps(job, src_bo->ttm.base.resv,
 						    DMA_RESV_USAGE_BOOKKEEP);
-			if (!err && src_bo != dst_bo)
+			if (!err && src_bo->ttm.base.resv != dst_bo->ttm.base.resv)
 				err = xe_sched_job_add_deps(job, dst_bo->ttm.base.resv,
 							    DMA_RESV_USAGE_BOOKKEEP);
 			if (err)