dma-buf: heaps: Rework heap allocation hooks to return struct dma_buf instead of fd

Every heap needs to create a dmabuf and then export it to a fd
via dma_buf_fd(), so to consolidate things a bit, have the heaps
just return a struct dmabuf * and let the top level
dma_heap_buffer_alloc() call handle creating the fd via
dma_buf_fd().

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: Ørjan Eide <orjan.eide@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Ezequiel Garcia <ezequiel@collabora.com>
Cc: Simon Ser <contact@emersion.fr>
Cc: James Jones <jajones@nvidia.com>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
 [sumits: minor reword of commit message]

Link: https://patchwork.freedesktop.org/patch/msgid/20210119204508.9256-3-john.stultz@linaro.org

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index afd22c9dbdcf..6b5db954569f 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -52,6 +52,9 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
 				 unsigned int fd_flags,
 				 unsigned int heap_flags)
 {
+	struct dma_buf *dmabuf;
+	int fd;
+
 	/*
 	 * Allocations from all heaps have to begin
 	 * and end on page boundaries.
@@ -60,7 +63,16 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
 	if (!len)
 		return -EINVAL;
 
-	return heap->ops->allocate(heap, len, fd_flags, heap_flags);
+	dmabuf = heap->ops->allocate(heap, len, fd_flags, heap_flags);
+	if (IS_ERR(dmabuf))
+		return PTR_ERR(dmabuf);
+
+	fd = dma_buf_fd(dmabuf, fd_flags);
+	if (fd < 0) {
+		dma_buf_put(dmabuf);
+		/* just return, as put will call release and that will free */
+	}
+	return fd;
 }
 
 static int dma_heap_open(struct inode *inode, struct file *file)