[RFT 1/5] drm/msm: Cleanup if pages_to_sg() fails

[Rob Clark <robin.clark@oss.qualcomm.com>]

We never really handled this.  But in practice mapping to smmu would
have failed without an sgt, which would have been pretty obvious.

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
---
 drivers/gpu/drm/msm/msm_gem.c | 41 ++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 130ae27ee00b..181b9ad32672 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -190,6 +190,7 @@ static void update_lru(struct drm_gem_object *obj)
 static struct page **get_pages(struct drm_gem_object *obj)
 {
 	struct msm_gem_object *msm_obj = to_msm_bo(obj);
+	int ret = 0;
 
 	msm_gem_assert_locked(obj);
 
@@ -209,19 +210,17 @@ static struct page **get_pages(struct drm_gem_object *obj)
 			return p;
 		}
 
-		update_device_mem(dev->dev_private, obj->size);
-
 		msm_obj->pages = p;
 
 		msm_obj->sgt = drm_prime_pages_to_sg(obj->dev, p, npages);
 		if (IS_ERR(msm_obj->sgt)) {
-			void *ptr = ERR_CAST(msm_obj->sgt);
-
 			DRM_DEV_ERROR(dev->dev, "failed to allocate sgt\n");
-			msm_obj->sgt = NULL;
-			return ptr;
+			ret = PTR_ERR(msm_obj->sgt);
+			goto error;
 		}
 
+		update_device_mem(dev->dev_private, obj->size);
+
 		/* For non-cached buffers, ensure the new pages are clean
 		 * because display controller, GPU, etc. are not coherent:
 		 */
@@ -232,6 +231,14 @@ static struct page **get_pages(struct drm_gem_object *obj)
 	}
 
 	return msm_obj->pages;
+
+error:
+	msm_obj->sgt = NULL;
+
+	drm_gem_put_pages(obj, msm_obj->pages, false, false);
+	msm_obj->pages = NULL;
+
+	return ERR_PTR(ret);
 }
 
 static void put_pages(struct drm_gem_object *obj)
@@ -246,18 +253,16 @@ static void put_pages(struct drm_gem_object *obj)
 		drm_gpuvm_bo_gem_evict(obj, true);
 
 	if (msm_obj->pages) {
-		if (msm_obj->sgt) {
-			/* For non-cached buffers, ensure the new
-			 * pages are clean because display controller,
-			 * GPU, etc. are not coherent:
-			 */
-			if (msm_obj->flags & MSM_BO_WC)
-				sync_for_cpu(msm_obj);
-
-			sg_free_table(msm_obj->sgt);
-			kfree(msm_obj->sgt);
-			msm_obj->sgt = NULL;
-		}
+		/* For non-cached buffers, ensure the new
+		 * pages are clean because display controller,
+		 * GPU, etc. are not coherent:
+		 */
+		if (msm_obj->flags & MSM_BO_WC)
+			sync_for_cpu(msm_obj);
+
+		sg_free_table(msm_obj->sgt);
+		kfree(msm_obj->sgt);
+		msm_obj->sgt = NULL;
 
 		update_device_mem(obj->dev->dev_private, -obj->size);
 
-- 
2.55.0