drm/ttm: add new function to check if bo is allowable to evict or swapout

extract a function as ttm_bo_evict_swapout_allowable since eviction and
swapout can share same logic.

v2: modify commit message and add description in the code

Reviewed-by: Thomas Hellström <thellstrom@vmware.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chuming Zhou <david1.zhou@amd.com>
Signed-off-by: Roger He <Hongbo.He@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 30 insertions, 10 deletions

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index b3a71acad6a8..ac2ab20ba9b2 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -708,6 +708,34 @@ bool ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
 }
 EXPORT_SYMBOL(ttm_bo_eviction_valuable);
 
+/**
+ * Check the target bo is allowable to be evicted or swapout, including cases:
+ *
+ * a. if share same reservation object with ctx->resv, have assumption
+ * reservation objects should already be locked, so not lock again and
+ * return true directly when either the opreation allow_reserved_eviction
+ * or the target bo already is in delayed free list;
+ *
+ * b. Otherwise, trylock it.
+ */
+static bool ttm_bo_evict_swapout_allowable(struct ttm_buffer_object *bo,
+                        struct ttm_operation_ctx *ctx, bool *locked)
+{
+        bool ret = false;
+
+        *locked = false;
+        if (bo->resv == ctx->resv) {
+                reservation_object_assert_held(bo->resv);
+                if (ctx->allow_reserved_eviction || !list_empty(&bo->ddestroy))
+                        ret = true;
+        } else {
+                *locked = reservation_object_trylock(bo->resv);
+                ret = *locked;
+        }
+
+        return ret;
+}
+
 static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
                                uint32_t mem_type,
                                const struct ttm_place *place,
@@ -723,21 +751,13 @@ static int ttm_mem_evict_first(struct ttm_bo_device *bdev,
         spin_lock(&glob->lru_lock);
         for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
                 list_for_each_entry(bo, &man->lru[i], lru) {
-                        if (bo->resv == ctx->resv) {
-                                if (!ctx->allow_reserved_eviction &&
-                                    list_empty(&bo->ddestroy))
-                                        continue;
-                        } else {
-                                locked = reservation_object_trylock(bo->resv);
-                                if (!locked)
-                                        continue;
-                        }
+                        if (!ttm_bo_evict_swapout_allowable(bo, ctx, &locked))
+                                continue;
 
                         if (place && !bdev->driver->eviction_valuable(bo,
                                                                       place)) {
                                 if (locked)
                                         reservation_object_unlock(bo->resv);
-                                locked = false;
                                 continue;
                         }
                         break;