drm/ttm: Use the LRU walker for eviction

Use the LRU walker for eviction. This helps
removing a lot of code with weird locking
semantics.

The functionality is slightly changed so that
when trylocked buffer objects are exhausted, we
continue to interleave walks with ticket-locks while
there is still progress made. The list walks are
not restarted in-between evictions.

Also provide a separate ttm_bo_evict_first()
function for its single user. The context of that
user allows sleeping dma_resv locks.

v6:
- Various cleanups suggested by Matthew Brost.
- Fix error return code of ttm_bo_evict_first(). (Matthew Brost)
- Fix an error check that was inverted. (Matthew Brost)
v7:
- Use s64 rather than long (Christian König)
- Early ttm_resource_cursor_fini() in ttm_bo_evict_first().
- Simplify check for bo_moved in ttm_bo_evict_first().
  (Christian König)
- Don't evict 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/20240705153206.68526-8-thomas.hellstrom@linux.intel.comSigned-off-by: Christian König <christian.koenig@amd.com>

drivers/gpu/drm/ttm/ttm_resource.c

@@ -495,24 +495,11 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
 	};
 	struct dma_fence *fence;
 	int ret;
-	unsigned i;
-
-	/*
-	 * Can't use standard list traversal since we're unlocking.
-	 */
 
-	spin_lock(&bdev->lru_lock);
-	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
-		while (!list_empty(&man->lru[i])) {
-			spin_unlock(&bdev->lru_lock);
-			ret = ttm_mem_evict_first(bdev, man, NULL, &ctx,
-						  NULL);
-			if (ret)
-				return ret;
-			spin_lock(&bdev->lru_lock);
-		}
-	}
-	spin_unlock(&bdev->lru_lock);
+	do {
+		ret = ttm_bo_evict_first(bdev, man, &ctx);
+		cond_resched();
+	} while (!ret);
 
 	spin_lock(&man->move_lock);
 	fence = dma_fence_get(man->move);

include/drm/ttm/ttm_bo.h

@@ -422,11 +422,9 @@ s64 ttm_bo_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
 		   s64 target);
 void ttm_bo_pin(struct ttm_buffer_object *bo);
 void ttm_bo_unpin(struct ttm_buffer_object *bo);
-int ttm_mem_evict_first(struct ttm_device *bdev,
-			struct ttm_resource_manager *man,
-			const struct ttm_place *place,
-			struct ttm_operation_ctx *ctx,
-			struct ww_acquire_ctx *ticket);
+int ttm_bo_evict_first(struct ttm_device *bdev,
+		       struct ttm_resource_manager *man,
+		       struct ttm_operation_ctx *ctx);
 vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
 			     struct vm_fault *vmf);
 vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,