[PATCH v2 16/16] drm/xe: Convert pinned suspend eviction for exhaustive eviction

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

Pinned suspend eviction and preparation for eviction validates
system memory for eviction buffers. Do that under a
validation exclusive lock to avoid interfering with other
processes validating system graphics memory.

v2:
- Avoid gotos from within xe_validation_guard().
- Adapt to signature change of xe_validation_guard().

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/gpu/drm/xe/xe_bo.c | 184 +++++++++++++++++++++----------------
 1 file changed, 103 insertions(+), 81 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 7a62629c88e0..9733f742525a 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -1139,43 +1139,47 @@ long xe_bo_shrink(struct ttm_operation_ctx *ctx, struct ttm_buffer_object *bo,
 int xe_bo_notifier_prepare_pinned(struct xe_bo *bo)
 {
 	struct xe_device *xe = ttm_to_xe_device(bo->ttm.bdev);
-	struct drm_exec *exec = XE_VALIDATION_UNIMPLEMENTED;
+	struct xe_validation_ctx ctx;
+	struct drm_exec exec;
 	struct xe_bo *backup;
 	int ret = 0;
 
-	xe_bo_lock(bo, false);
+	xe_validation_guard(&ctx, &xe->val, &exec, (struct xe_val_flags) {.exclusive = true}, ret) {
+		ret = drm_exec_lock_obj(&exec, &bo->ttm.base);
+		drm_exec_retry_on_contention(&exec);
+		xe_assert(xe, !ret);
+		xe_assert(xe, !bo->backup_obj);
 
-	xe_assert(xe, !bo->backup_obj);
+		/*
+		 * Since this is called from the PM notifier we might have raced with
+		 * someone unpinning this after we dropped the pinned list lock and
+		 * grabbing the above bo lock.
+		 */
+		if (!xe_bo_is_pinned(bo))
+			break;
 
-	/*
-	 * Since this is called from the PM notifier we might have raced with
-	 * someone unpinning this after we dropped the pinned list lock and
-	 * grabbing the above bo lock.
-	 */
-	if (!xe_bo_is_pinned(bo))
-		goto out_unlock_bo;
+		if (!xe_bo_is_vram(bo))
+			break;
 
-	if (!xe_bo_is_vram(bo))
-		goto out_unlock_bo;
+		if (bo->flags & XE_BO_FLAG_PINNED_NORESTORE)
+			break;
 
-	if (bo->flags & XE_BO_FLAG_PINNED_NORESTORE)
-		goto out_unlock_bo;
+		backup = xe_bo_init_locked(xe, NULL, NULL, bo->ttm.base.resv, NULL, xe_bo_size(bo),
+					   DRM_XE_GEM_CPU_CACHING_WB, ttm_bo_type_kernel,
+					   XE_BO_FLAG_SYSTEM | XE_BO_FLAG_NEEDS_CPU_ACCESS |
+					   XE_BO_FLAG_PINNED, &exec);
+		if (IS_ERR(backup)) {
+			drm_exec_retry_on_contention(&exec);
+			ret = PTR_ERR(backup);
+			xe_validation_retry_on_oom(&ctx, &ret);
+			break;
+		}
 
-	backup = xe_bo_init_locked(xe, NULL, NULL, bo->ttm.base.resv, NULL, xe_bo_size(bo),
-				   DRM_XE_GEM_CPU_CACHING_WB, ttm_bo_type_kernel,
-				   XE_BO_FLAG_SYSTEM | XE_BO_FLAG_NEEDS_CPU_ACCESS |
-				   XE_BO_FLAG_PINNED, exec);
-	if (IS_ERR(backup)) {
-		ret = PTR_ERR(backup);
-		goto out_unlock_bo;
+		backup->parent_obj = xe_bo_get(bo); /* Released by bo_destroy */
+		ttm_bo_pin(&backup->ttm);
+		bo->backup_obj = backup;
 	}
 
-	backup->parent_obj = xe_bo_get(bo); /* Released by bo_destroy */
-	ttm_bo_pin(&backup->ttm);
-	bo->backup_obj = backup;
-
-out_unlock_bo:
-	xe_bo_unlock(bo);
 	return ret;
 }
 
@@ -1201,57 +1205,12 @@ int xe_bo_notifier_unprepare_pinned(struct xe_bo *bo)
 	return 0;
 }
 
-/**
- * xe_bo_evict_pinned() - Evict a pinned VRAM object to system memory
- * @bo: The buffer object to move.
- *
- * On successful completion, the object memory will be moved to system memory.
- *
- * This is needed to for special handling of pinned VRAM object during
- * suspend-resume.
- *
- * Return: 0 on success. Negative error code on failure.
- */
-int xe_bo_evict_pinned(struct xe_bo *bo)
+static int xe_bo_evict_pinned_copy(struct xe_bo *bo, struct xe_bo *backup)
 {
-	struct xe_device *xe = ttm_to_xe_device(bo->ttm.bdev);
-	struct drm_exec *exec = XE_VALIDATION_UNIMPLEMENTED;
-	struct xe_bo *backup = bo->backup_obj;
-	bool backup_created = false;
+	struct xe_device *xe = xe_bo_device(bo);
 	bool unmap = false;
 	int ret = 0;
 
-	xe_bo_lock(bo, false);
-
-	if (WARN_ON(!bo->ttm.resource)) {
-		ret = -EINVAL;
-		goto out_unlock_bo;
-	}
-
-	if (WARN_ON(!xe_bo_is_pinned(bo))) {
-		ret = -EINVAL;
-		goto out_unlock_bo;
-	}
-
-	if (!xe_bo_is_vram(bo))
-		goto out_unlock_bo;
-
-	if (bo->flags & XE_BO_FLAG_PINNED_NORESTORE)
-		goto out_unlock_bo;
-
-	if (!backup) {
-		backup = xe_bo_init_locked(xe, NULL, NULL, bo->ttm.base.resv, NULL, xe_bo_size(bo),
-					   DRM_XE_GEM_CPU_CACHING_WB, ttm_bo_type_kernel,
-					   XE_BO_FLAG_SYSTEM | XE_BO_FLAG_NEEDS_CPU_ACCESS |
-					   XE_BO_FLAG_PINNED, exec);
-		if (IS_ERR(backup)) {
-			ret = PTR_ERR(backup);
-			goto out_unlock_bo;
-		}
-		backup->parent_obj = xe_bo_get(bo); /* Released by bo_destroy */
-		backup_created = true;
-	}
-
 	if (xe_bo_is_user(bo) || (bo->flags & XE_BO_FLAG_PINNED_LATE_RESTORE)) {
 		struct xe_migrate *migrate;
 		struct dma_fence *fence;
@@ -1289,7 +1248,7 @@ int xe_bo_evict_pinned(struct xe_bo *bo)
 		if (iosys_map_is_null(&bo->vmap)) {
 			ret = xe_bo_vmap(bo);
 			if (ret)
-				goto out_backup;
+				goto out_vunmap;
 			unmap = true;
 		}
 
@@ -1299,15 +1258,78 @@ int xe_bo_evict_pinned(struct xe_bo *bo)
 
 	if (!bo->backup_obj)
 		bo->backup_obj = backup;
-
-out_backup:
+out_vunmap:
 	xe_bo_vunmap(backup);
-	if (ret && backup_created)
-		xe_bo_put(backup);
-out_unlock_bo:
+out_backup:
 	if (unmap)
 		xe_bo_vunmap(bo);
-	xe_bo_unlock(bo);
+
+	return ret;
+}
+
+/**
+ * xe_bo_evict_pinned() - Evict a pinned VRAM object to system memory
+ * @bo: The buffer object to move.
+ *
+ * On successful completion, the object memory will be moved to system memory.
+ *
+ * This is needed to for special handling of pinned VRAM object during
+ * suspend-resume.
+ *
+ * Return: 0 on success. Negative error code on failure.
+ */
+int xe_bo_evict_pinned(struct xe_bo *bo)
+{
+	struct xe_device *xe = ttm_to_xe_device(bo->ttm.bdev);
+	struct xe_validation_ctx ctx;
+	struct drm_exec exec;
+	struct xe_bo *backup = bo->backup_obj;
+	bool backup_created = false;
+	int ret = 0;
+
+	xe_validation_guard(&ctx, &xe->val, &exec, (struct xe_val_flags) {.exclusive = true}, ret) {
+		ret = drm_exec_lock_obj(&exec, &bo->ttm.base);
+		drm_exec_retry_on_contention(&exec);
+		xe_assert(xe, !ret);
+
+		if (WARN_ON(!bo->ttm.resource)) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (WARN_ON(!xe_bo_is_pinned(bo))) {
+			ret = -EINVAL;
+			break;
+		}
+
+		if (!xe_bo_is_vram(bo))
+			break;
+
+		if (bo->flags & XE_BO_FLAG_PINNED_NORESTORE)
+			break;
+
+		if (!backup) {
+			backup = xe_bo_init_locked(xe, NULL, NULL, bo->ttm.base.resv, NULL,
+						   xe_bo_size(bo),
+						   DRM_XE_GEM_CPU_CACHING_WB, ttm_bo_type_kernel,
+						   XE_BO_FLAG_SYSTEM | XE_BO_FLAG_NEEDS_CPU_ACCESS |
+						   XE_BO_FLAG_PINNED, &exec);
+			if (IS_ERR(backup)) {
+				drm_exec_retry_on_contention(&exec);
+				ret = PTR_ERR(backup);
+				xe_validation_retry_on_oom(&ctx, &ret);
+				break;
+			}
+			backup->parent_obj = xe_bo_get(bo); /* Released by bo_destroy */
+			backup_created = true;
+		}
+
+		ret = xe_bo_evict_pinned_copy(bo, backup);
+	}
+
+	if (ret && backup_created)
+		xe_bo_put(backup);
+
 	return ret;
 }
 
-- 
2.50.1