drm/ttm: Use the LRU walker helper for swapping

Rework the TTM swapping to use the LRU walker helper.
This helps fixing up the ttm_bo_swapout() interface
to be consistent about not requiring any locking.

For now mimic the current behaviour of using trylock
only. We could be using ticket-locks here but defer
that until it's deemed necessary. The TTM swapout
functionality is a bit weird anyway since it
alternates between memory types without exhausting
TTM_PL_SYSTEM first.

Intentionally keep pages as the unit of progress since
changing that to bytes is an unrelated change that can
be done later.

v6:
- Improve on error code translation in the swapout callback
  (Matthew Brost).
v7:
- Use s64 rather than long.
- Remove ttm_resource_cursor_fini() since it's no longer used.
- Rename ttm_resource_cursor_fini_locked() to
  ttm_resource_cursor_fini().
- Don't swap out pinned bos.

Cc: Christian König <christian.koenig@amd.com>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com> #v6
Link: https://patchwork.freedesktop.org/patch/msgid/20240705153206.68526-7-thomas.hellstrom@linux.intel.com
Signed-off-by: Christian König <christian.koenig@amd.com>

1 files changed, 3 insertions, 20 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index b6a2daac5518..b43d04a1dc91 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -81,14 +81,14 @@ static void ttm_bulk_move_drop_cursors(struct ttm_lru_bulk_move *bulk)
 }
 
 /**
- * ttm_resource_cursor_fini_locked() - Finalize the LRU list cursor usage
+ * ttm_resource_cursor_fini() - Finalize the LRU list cursor usage
  * @cursor: The struct ttm_resource_cursor to finalize.
  *
  * The function pulls the LRU list cursor off any lists it was previusly
  * attached to. Needs to be called with the LRU lock held. The function
  * can be called multiple times after eachother.
  */
-void ttm_resource_cursor_fini_locked(struct ttm_resource_cursor *cursor)
+void ttm_resource_cursor_fini(struct ttm_resource_cursor *cursor)
 {
 	lockdep_assert_held(&cursor->man->bdev->lru_lock);
 	list_del_init(&cursor->hitch.link);
@@ -96,23 +96,6 @@ void ttm_resource_cursor_fini_locked(struct ttm_resource_cursor *cursor)
 }
 
 /**
- * ttm_resource_cursor_fini() - Finalize the LRU list cursor usage
- * @cursor: The struct ttm_resource_cursor to finalize.
- *
- * The function pulls the LRU list cursor off any lists it was previusly
- * attached to. Needs to be called without the LRU list lock held. The
- * function can be called multiple times after eachother.
- */
-void ttm_resource_cursor_fini(struct ttm_resource_cursor *cursor)
-{
-	spinlock_t *lru_lock = &cursor->man->bdev->lru_lock;
-
-	spin_lock(lru_lock);
-	ttm_resource_cursor_fini_locked(cursor);
-	spin_unlock(lru_lock);
-}
-
-/**
  * ttm_lru_bulk_move_init - initialize a bulk move structure
  * @bulk: the structure to init
  *
@@ -662,7 +645,7 @@ ttm_resource_manager_next(struct ttm_resource_cursor *cursor)
 		ttm_resource_cursor_clear_bulk(cursor);
 	}
 
-	ttm_resource_cursor_fini_locked(cursor);
+	ttm_resource_cursor_fini(cursor);
 
 	return NULL;
 }