udmabuf: introduce udmabuf init and deinit helper

After udmabuf is allocated, its resources need to be initialized,
including various array structures. The current array structure has
already been greatly expanded.

Also, before udmabuf needs to be kfree, the occupied resources need to
be released.

This part is repetitive and maybe overlooked.

This patch give a helper function when init and deinit, by this,
reduce duplicate code.

Signed-off-by: Huan Yang <link@vivo.com>
Acked-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240918025238.2957823-6-link@vivo.com

drivers/dma-buf/udmabuf.c

@@ -224,6 +224,28 @@ static int add_to_unpin_list(struct list_head *unpin_list,
 	return 0;
 }
 
+static __always_inline int init_udmabuf(struct udmabuf *ubuf, pgoff_t pgcnt)
+{
+	INIT_LIST_HEAD(&ubuf->unpin_list);
+
+	ubuf->folios = kvmalloc_array(pgcnt, sizeof(*ubuf->folios), GFP_KERNEL);
+	if (!ubuf->folios)
+		return -ENOMEM;
+
+	ubuf->offsets = kvcalloc(pgcnt, sizeof(*ubuf->offsets), GFP_KERNEL);
+	if (!ubuf->offsets)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static __always_inline void deinit_udmabuf(struct udmabuf *ubuf)
+{
+	unpin_all_folios(&ubuf->unpin_list);
+	kvfree(ubuf->offsets);
+	kvfree(ubuf->folios);
+}
+
 static void release_udmabuf(struct dma_buf *buf)
 {
 	struct udmabuf *ubuf = buf->priv;
@@ -232,9 +254,7 @@ static void release_udmabuf(struct dma_buf *buf)
 	if (ubuf->sg)
 		put_sg_table(dev, ubuf->sg, DMA_BIDIRECTIONAL);
 
-	unpin_all_folios(&ubuf->unpin_list);
-	kvfree(ubuf->offsets);
-	kvfree(ubuf->folios);
+	deinit_udmabuf(ubuf);
 	kfree(ubuf);
 }
 
@@ -392,33 +412,24 @@ static long udmabuf_create(struct miscdevice *device,
 	if (!ubuf)
 		return -ENOMEM;
 
-	INIT_LIST_HEAD(&ubuf->unpin_list);
 	pglimit = (size_limit_mb * 1024 * 1024) >> PAGE_SHIFT;
 	for (i = 0; i < head->count; i++) {
 		if (!PAGE_ALIGNED(list[i].offset))
-			goto err;
+			goto err_noinit;
 		if (!PAGE_ALIGNED(list[i].size))
-			goto err;
+			goto err_noinit;
 
 		pgcnt += list[i].size >> PAGE_SHIFT;
 		if (pgcnt > pglimit)
-			goto err;
+			goto err_noinit;
 	}
 
 	if (!pgcnt)
-		goto err;
+		goto err_noinit;
 
-	ubuf->folios = kvmalloc_array(pgcnt, sizeof(*ubuf->folios), GFP_KERNEL);
-	if (!ubuf->folios) {
-		ret = -ENOMEM;
+	ret = init_udmabuf(ubuf, pgcnt);
+	if (ret)
 		goto err;
-	}
-
-	ubuf->offsets = kvcalloc(pgcnt, sizeof(*ubuf->offsets), GFP_KERNEL);
-	if (!ubuf->offsets) {
-		ret = -ENOMEM;
-		goto err;
-	}
 
 	for (i = 0; i < head->count; i++) {
 		struct file *memfd = fget(list[i].memfd);
@@ -449,9 +460,8 @@ static long udmabuf_create(struct miscdevice *device,
 	return ret;
 
 err:
-	unpin_all_folios(&ubuf->unpin_list);
-	kvfree(ubuf->offsets);
-	kvfree(ubuf->folios);
+	deinit_udmabuf(ubuf);
+err_noinit:
 	kfree(ubuf);
 	return ret;
 }