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
(cherry picked from commit c7f59e3dd60313071a989227dcb69094f499d310)
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index afd22c9..6b5db95 100644 (file)
--- 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 364fc2f..5d64ecc 100644 (file)
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -271,10 +271,10 @@ 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;
@@ -289,7 +289,7 @@ 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);
@@ -348,15 +348,7 @@ 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);
@@ -365,7 +357,7 @@ free_cma:
 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 405351a..29e49ac 100644 (file)
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -331,10 +331,10 @@ 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);
@@ -349,7 +349,7 @@ 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);
@@ -399,14 +399,7 @@ 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) {
@@ -420,7 +413,7 @@ free_buffer:
                __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 454e354..5bc5c94 100644 (file)
--- 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);
 };
 
 /**