android-mainline/ANDROID-dma-heap-Rework-allocation-calls-to-return-struct-dma_buf-instead-of-fd.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: John Stultz <john.stultz@linaro.org>
Date: Fri, 14 Aug 2020 22:42:09 +0000
Subject: ANDROID: dma-heap: Rework allocation calls to return struct dma_buf
 instead of fd

While most uses will want to allocate a fd for a dmabuf, there
are some cases where it might be useful to have just a dma_buf structure.

So refactor the heap allocaiton functions to return a struct dma_buf
and add a dma_heap_bufferfd_alloc() function to convert that return a fd.

[CPNOTE: 06/07/21] Lee: Asked vendor for an update via the bug

Signed-off-by: John Stultz <john.stultz@linaro.org>
Change-Id: Id6fd7e8471b9555a08bcdf8ca210feb589fa51c1
Bug: 154341375
---
 drivers/dma-buf/dma-heap.c | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c
@@ -67,24 +67,40 @@ static struct dma_heap *dma_heap_find(const char *name)
 	return NULL;
 }
 
-static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
-				 unsigned int fd_flags,
-				 unsigned int heap_flags)
+void dma_heap_buffer_free(struct dma_buf *dmabuf)
+{
+	dma_buf_put(dmabuf);
+}
+
+struct dma_buf *dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
+				      unsigned int fd_flags,
+				      unsigned int heap_flags)
 {
 	if (fd_flags & ~DMA_HEAP_VALID_FD_FLAGS)
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 
 	if (heap_flags & ~DMA_HEAP_VALID_HEAP_FLAGS)
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	/*
 	 * Allocations from all heaps have to begin
 	 * and end on page boundaries.
 	 */
 	len = PAGE_ALIGN(len);
 	if (!len)
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
+
+	return heap->ops->allocate(heap, len, fd_flags, heap_flags);
+}
+
+int dma_heap_bufferfd_alloc(struct dma_heap *heap, size_t len,
+			    unsigned int fd_flags,
+			    unsigned int heap_flags)
+{
+	struct dma_buf *dmabuf;
+	int fd;
+
+	dmabuf = dma_heap_buffer_alloc(heap, len, fd_flags, heap_flags);
 
-	dmabuf = heap->ops->allocate(heap, len, fd_flags, heap_flags);
 	if (IS_ERR(dmabuf))
 		return PTR_ERR(dmabuf);
 
@@ -94,6 +110,7 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len,
 		/* just return, as put will call release and that will free */
 	}
 	return fd;
+
 }
 
 static int dma_heap_open(struct inode *inode, struct file *file)
@@ -122,9 +139,9 @@ static long dma_heap_ioctl_allocate(struct file *file, void *data)
 	if (heap_allocation->fd)
 		return -EINVAL;
 
-	fd = dma_heap_buffer_alloc(heap, heap_allocation->len,
-				   heap_allocation->fd_flags,
-				   heap_allocation->heap_flags);
+	fd = dma_heap_bufferfd_alloc(heap, heap_allocation->len,
+				     heap_allocation->fd_flags,
+				     heap_allocation->heap_flags);
 	if (fd < 0)
 		return fd;