From: John Stultz <[email protected]> This allows drivers who don't want to create their own DMA-BUF exporter to be able to allocate DMA-BUFs directly from existing DMA-BUF Heaps.
There is some concern that the premise of DMA-BUF heaps is that userland knows better about what type of heap memory is needed for a pipeline, so it would likely be best for drivers to import and fill DMA-BUFs allocated by userland instead of allocating one themselves, but this is still up for debate. Signed-off-by: John Stultz <[email protected]> Signed-off-by: T.J. Mercier <[email protected]> Signed-off-by: Yong Wu <[email protected]> [Yong: Fix the checkpatch alignment warning] --- drivers/dma-buf/dma-heap.c | 60 ++++++++++++++++++++++++++++---------- include/linux/dma-heap.h | 25 ++++++++++++++++ 2 files changed, 69 insertions(+), 16 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index dcc0e38c61fa..908bb30dc864 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -53,12 +53,15 @@ static dev_t dma_heap_devt; static struct class *dma_heap_class; static DEFINE_XARRAY_ALLOC(dma_heap_minors); -static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, - unsigned int fd_flags, - unsigned int heap_flags) +struct dma_buf *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; + if (fd_flags & ~DMA_HEAP_VALID_FD_FLAGS) + return ERR_PTR(-EINVAL); + + if (heap_flags & ~DMA_HEAP_VALID_HEAP_FLAGS) + return ERR_PTR(-EINVAL); /* * Allocations from all heaps have to begin @@ -66,9 +69,20 @@ static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, */ len = PAGE_ALIGN(len); if (!len) - return -EINVAL; + return ERR_PTR(-EINVAL); - dmabuf = heap->ops->allocate(heap, len, fd_flags, heap_flags); + return heap->ops->allocate(heap, len, fd_flags, heap_flags); +} +EXPORT_SYMBOL_GPL(dma_heap_buffer_alloc); + +static 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); if (IS_ERR(dmabuf)) return PTR_ERR(dmabuf); @@ -106,15 +120,9 @@ static long dma_heap_ioctl_allocate(struct file *file, void *data) if (heap_allocation->fd) return -EINVAL; - if (heap_allocation->fd_flags & ~DMA_HEAP_VALID_FD_FLAGS) - return -EINVAL; - - if (heap_allocation->heap_flags & ~DMA_HEAP_VALID_HEAP_FLAGS) - 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; @@ -205,6 +213,7 @@ const char *dma_heap_get_name(struct dma_heap *heap) { return heap->name; } +EXPORT_SYMBOL_GPL(dma_heap_get_name); struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) { @@ -290,6 +299,24 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) kfree(heap); return err_ret; } +EXPORT_SYMBOL_GPL(dma_heap_add); + +struct dma_heap *dma_heap_find(const char *name) +{ + struct dma_heap *h; + + mutex_lock(&heap_list_lock); + list_for_each_entry(h, &heap_list, list) { + if (!strcmp(h->name, name)) { + kref_get(&h->refcount); + mutex_unlock(&heap_list_lock); + return h; + } + } + mutex_unlock(&heap_list_lock); + return NULL; +} +EXPORT_SYMBOL_GPL(dma_heap_find); static void dma_heap_release(struct kref *ref) { @@ -315,6 +342,7 @@ void dma_heap_put(struct dma_heap *h) kref_put(&h->refcount, dma_heap_release); mutex_unlock(&heap_list_lock); } +EXPORT_SYMBOL_GPL(dma_heap_put); static char *dma_heap_devnode(const struct device *dev, umode_t *mode) { diff --git a/include/linux/dma-heap.h b/include/linux/dma-heap.h index f3c678892c5c..59e70f6c7a60 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -64,10 +64,35 @@ const char *dma_heap_get_name(struct dma_heap *heap); */ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info); +/** + * dma_heap_find - get the heap registered with the specified name + * @name: Name of the DMA-Heap to find + * + * Returns: + * The DMA-Heap with the provided name. + * + * NOTE: DMA-Heaps returned from this function MUST be released using + * dma_heap_put() when the user is done to enable the heap to be unloaded. + */ +struct dma_heap *dma_heap_find(const char *name); + /** * dma_heap_put - drops a reference to a dmabuf heap, potentially freeing it * @heap: the heap whose reference count to decrement */ void dma_heap_put(struct dma_heap *heap); +/** + * dma_heap_buffer_alloc - Allocate dma-buf from a dma_heap + * @heap: DMA-Heap to allocate from + * @len: size to allocate in bytes + * @fd_flags: flags to set on returned dma-buf fd + * @heap_flags: flags to pass to the dma heap + * + * This is for internal dma-buf allocations only. Free returned buffers with dma_buf_put(). + */ +struct dma_buf *dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, + unsigned int fd_flags, + unsigned int heap_flags); + #endif /* _DMA_HEAPS_H */ -- 2.25.1
