drm/msm/gem: Consolidate pin/unpin paths

Avoid having multiple spots where we increment/decrement pin_count (and
associated LRU updating)
Signed-off-by: Rob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/496130/
Link: https://lore.kernel.org/r/20220802155152.1727594-8-robdclark@gmail.com

drivers/gpu/drm/msm/msm_gem.c

@@ -190,7 +190,7 @@ static struct page **msm_gem_pin_pages_locked(struct drm_gem_object *obj)
 
 	p = get_pages(obj);
 	if (!IS_ERR(p)) {
-		msm_obj->pin_count++;
+		to_msm_bo(obj)->pin_count++;
 		update_lru(obj);
 	}
 
@@ -213,9 +213,7 @@ void msm_gem_unpin_pages(struct drm_gem_object *obj)
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
 
 	msm_gem_lock(obj);
-	msm_obj->pin_count--;
-	GEM_WARN_ON(msm_obj->pin_count < 0);
-	update_lru(obj);
+	msm_gem_unpin_locked(obj);
 	msm_gem_unlock(obj);
 }
 
@@ -436,14 +434,13 @@ int msm_gem_pin_vma_locked(struct drm_gem_object *obj, struct msm_gem_vma *vma)
 	if (GEM_WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED))
 		return -EBUSY;
 
-	pages = get_pages(obj);
+	pages = msm_gem_pin_pages_locked(obj);
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);
 
 	ret = msm_gem_map_vma(vma->aspace, vma, prot, msm_obj->sgt, obj->size);
-
-	if (!ret)
-		msm_obj->pin_count++;
+	if (ret)
+		msm_gem_unpin_locked(obj);
 
 	return ret;
 }