[RESEND][PATCH 3/3] dma-buf: heaps: Rework heep allocation hooks to return struct dma_buf instead of fd

From: John Stultz
Date: Tue Jan 19 2021 - 15:46:56 EST


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@xxxxxxxxxx>
Cc: Liam Mark <lmark@xxxxxxxxxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Brian Starkey <Brian.Starkey@xxxxxxx>
Cc: Hridya Valsaraju <hridya@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Sandeep Patil <sspatil@xxxxxxxxxx>
Cc: Daniel Mentz <danielmentz@xxxxxxxxxx>
Cc: Chris Goldsworthy <cgoldswo@xxxxxxxxxxxxxx>
Cc: Ørjan Eide <orjan.eide@xxxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
Cc: Simon Ser <contact@xxxxxxxxxxx>
Cc: James Jones <jajones@xxxxxxxxxx>
Cc: linux-media@xxxxxxxxxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/dma-buf/dma-heap.c | 14 +++++++++++++-
drivers/dma-buf/heaps/cma_heap.c | 22 +++++++---------------
drivers/dma-buf/heaps/system_heap.c | 21 +++++++--------------
include/linux/dma-heap.h | 12 ++++++------
4 files changed, 33 insertions(+), 36 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)
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 0c76cbc3fb11..985c41ffd85b 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -272,10 +272,10 @@ static const struct dma_buf_ops cma_heap_buf_ops = {
.release = cma_heap_dma_buf_release,
};

-static int cma_heap_allocate(struct dma_heap *heap,
- unsigned long len,
- unsigned long fd_flags,
- unsigned long heap_flags)
+static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
+ unsigned long len,
+ unsigned long fd_flags,
+ unsigned long heap_flags)
{
struct cma_heap *cma_heap = dma_heap_get_drvdata(heap);
struct cma_heap_buffer *buffer;
@@ -290,7 +290,7 @@ static int cma_heap_allocate(struct dma_heap *heap,

buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (!buffer)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

INIT_LIST_HEAD(&buffer->attachments);
mutex_init(&buffer->lock);
@@ -349,15 +349,7 @@ static int cma_heap_allocate(struct dma_heap *heap,
ret = PTR_ERR(dmabuf);
goto free_pages;
}
-
- ret = dma_buf_fd(dmabuf, fd_flags);
- if (ret < 0) {
- dma_buf_put(dmabuf);
- /* just return, as put will call release and that will free */
- return ret;
- }
-
- return ret;
+ return dmabuf;

free_pages:
kfree(buffer->pages);
@@ -366,7 +358,7 @@ static int cma_heap_allocate(struct dma_heap *heap,
free_buffer:
kfree(buffer);

- return ret;
+ return ERR_PTR(ret);
}

static const struct dma_heap_ops cma_heap_ops = {
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index 2321c91891f6..7b154424aeb3 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -332,10 +332,10 @@ static struct page *alloc_largest_available(unsigned long size,
return NULL;
}

-static int system_heap_allocate(struct dma_heap *heap,
- unsigned long len,
- unsigned long fd_flags,
- unsigned long heap_flags)
+static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
+ unsigned long len,
+ unsigned long fd_flags,
+ unsigned long heap_flags)
{
struct system_heap_buffer *buffer;
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
@@ -350,7 +350,7 @@ static int system_heap_allocate(struct dma_heap *heap,

buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (!buffer)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

INIT_LIST_HEAD(&buffer->attachments);
mutex_init(&buffer->lock);
@@ -400,14 +400,7 @@ static int system_heap_allocate(struct dma_heap *heap,
ret = PTR_ERR(dmabuf);
goto free_pages;
}
-
- ret = dma_buf_fd(dmabuf, fd_flags);
- if (ret < 0) {
- dma_buf_put(dmabuf);
- /* just return, as put will call release and that will free */
- return ret;
- }
- return ret;
+ return dmabuf;

free_pages:
for_each_sgtable_sg(table, sg, i) {
@@ -421,7 +414,7 @@ static int system_heap_allocate(struct dma_heap *heap,
__free_pages(page, compound_order(page));
kfree(buffer);

- return ret;
+ return ERR_PTR(ret);
}

static const struct dma_heap_ops system_heap_ops = {
diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h
index 454e354d1ffb..5bc5c946af58 100644
--- a/include/linux/dma-heap.h
+++ b/include/linux/dma-heap.h
@@ -16,15 +16,15 @@ struct dma_heap;

/**
* struct dma_heap_ops - ops to operate on a given heap
- * @allocate: allocate dmabuf and return fd
+ * @allocate: allocate dmabuf and return struct dma_buf ptr
*
- * allocate returns dmabuf fd on success, -errno on error.
+ * allocate returns dmabuf on success, ERR_PTR(-errno) on error.
*/
struct dma_heap_ops {
- int (*allocate)(struct dma_heap *heap,
- unsigned long len,
- unsigned long fd_flags,
- unsigned long heap_flags);
+ struct dma_buf *(*allocate)(struct dma_heap *heap,
+ unsigned long len,
+ unsigned long fd_flags,
+ unsigned long heap_flags);
};

/**
--
2.17.1