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] Signed-off-by: Yunfei Dong <[email protected]> Signed-off-by: Florent Tomasin <[email protected]> [Florent: Rebase] Signed-off-by: Ketil Johnsen <[email protected]> [Ketil: Rebase] --- drivers/dma-buf/dma-heap.c | 80 ++++++++++++++++++++++++++++++-------- include/linux/dma-heap.h | 6 +++ 2 files changed, 70 insertions(+), 16 deletions(-) diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c index 9fd365ddbd517..854d40d789ff2 100644 --- a/drivers/dma-buf/dma-heap.c +++ b/drivers/dma-buf/dma-heap.c @@ -57,12 +57,24 @@ module_param(mem_accounting, bool, 0444); MODULE_PARM_DESC(mem_accounting, "Enable cgroup-based memory accounting for dma-buf heap allocations (default=false)."); -static int dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, - u32 fd_flags, - u64 heap_flags) +/** + * 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, + u32 fd_flags, + u64 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 @@ -70,9 +82,20 @@ 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); + + return heap->ops->allocate(heap, len, fd_flags, heap_flags); +} +EXPORT_SYMBOL_NS_GPL(dma_heap_buffer_alloc, "DMA_BUF_HEAP"); - dmabuf = heap->ops->allocate(heap, len, fd_flags, heap_flags); +static int dma_heap_bufferfd_alloc(struct dma_heap *heap, size_t len, + u32 fd_flags, + u64 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); @@ -110,15 +133,9 @@ 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; @@ -317,6 +334,36 @@ struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info) } EXPORT_SYMBOL_NS_GPL(dma_heap_add, "DMA_BUF_HEAP"); +/** + * 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) +{ + struct dma_heap *h; + + mutex_lock(&heap_list_lock); + list_for_each_entry(h, &heap_list, list) { + if (!kref_get_unless_zero(&h->refcount)) + continue; + + if (!strcmp(h->name, name)) { + mutex_unlock(&heap_list_lock); + return h; + } + dma_heap_put(h); + } + mutex_unlock(&heap_list_lock); + return NULL; +} +EXPORT_SYMBOL_NS_GPL(dma_heap_find, "DMA_BUF_HEAP"); + static void dma_heap_release(struct kref *ref) { struct dma_heap *heap = container_of(ref, struct dma_heap, refcount); @@ -341,6 +388,7 @@ void dma_heap_put(struct dma_heap *heap) { kref_put(&heap->refcount, dma_heap_release); } +EXPORT_SYMBOL_NS_GPL(dma_heap_put, "DMA_BUF_HEAP"); 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 ff57741700f5f..c3351f8a1f8cf 100644 --- a/include/linux/dma-heap.h +++ b/include/linux/dma-heap.h @@ -46,8 +46,14 @@ const char *dma_heap_get_name(struct dma_heap *heap); struct dma_heap *dma_heap_add(const struct dma_heap_export_info *exp_info); +struct dma_heap *dma_heap_find(const char *name); + void dma_heap_put(struct dma_heap *heap); +struct dma_buf *dma_heap_buffer_alloc(struct dma_heap *heap, size_t len, + u32 fd_flags, + u64 heap_flags); + extern bool mem_accounting; #endif /* _DMA_HEAPS_H */ -- 2.43.0
