[PATCH 11/12] drm/ttm: support using drm_exec during eviction v4

[Christian König]

Allow specifying a drm_exec object in TTMs operation context which is
used to lock objects during eviction.

This allows to handle deadlocks much more gracefully and with that
avoid returning -ENOMEM on heavily contended domains.

v2: rebased on top of Thomas work
v3: rebased again
v4: adjust to dma_resv changes

Signed-off-by: Christian König <christian.koenig@xxxxxxx>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c | 12 ++++++++----
 include/drm/ttm/ttm_bo.h          |  5 +++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 1bdd69643c313..570640ae79d84 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -38,6 +38,7 @@
 #include <drm/ttm/ttm_tt.h>
 
 #include <drm/drm_cache.h>
+#include <drm/drm_exec.h>
 
 struct ttm_transfer_obj {
 	struct ttm_buffer_object base;
@@ -839,7 +840,9 @@ static int ttm_lru_walk_ticketlock(struct ttm_bo_lru_cursor *curs,
 	struct ttm_lru_walk_arg *arg = curs->arg;
 	int ret;
 
-	if (arg->ctx->interruptible)
+	if (arg->ctx->exec)
+		ret = drm_exec_lock_resv(arg->ctx->exec, resv);
+	else if (arg->ctx->interruptible)
 		ret = dma_resv_lock_interruptible(resv, arg->ticket);
 	else
 		ret = dma_resv_lock(resv, arg->ticket);
@@ -853,7 +856,8 @@ static int ttm_lru_walk_ticketlock(struct ttm_bo_lru_cursor *curs,
 		 * trylocking for this walk.
 		 */
 		arg->ticket = NULL;
-	} else if (ret == -EDEADLK) {
+
+	} else if (!arg->ctx->exec && ret == -EDEADLK) {
 		/* Caller needs to exit the ww transaction. */
 		ret = -ENOSPC;
 	}
@@ -993,8 +997,8 @@ __ttm_bo_lru_cursor_iter(struct ttm_bo_lru_cursor *curs, bool first)
 		if (!ttm_lru_walk_trylock(curs, res->bo->base.resv)) {
 			struct dma_resv *resv;
 
-			if (!arg->ticket || arg->ctx->no_wait_gpu ||
-			    arg->trylock_only) {
+			if ((!arg->ticket || arg->ctx->no_wait_gpu ||
+			     arg->trylock_only) && !arg->ctx->exec) {
 				spin_unlock(lru_lock);
 				continue;
 			}
diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
index e1221e3be7bda..0ffa84a5caa65 100644
--- a/include/drm/ttm/ttm_bo.h
+++ b/include/drm/ttm/ttm_bo.h
@@ -186,6 +186,11 @@ struct ttm_operation_ctx {
 	 * @bytes_moved: Statistics on how many bytes have been moved.
 	 */
 	uint64_t bytes_moved;
+	/*
+	 * @exec: optional drm_exec object to use for locking and contention
+	 * handling
+	 */
+	struct drm_exec *exec;
 };
 
 struct ttm_lru_walk;
-- 
2.43.0