diff options
Diffstat (limited to 'include/uapi/linux/dma-buf.h')
| -rw-r--r-- | include/uapi/linux/dma-buf.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/uapi/linux/dma-buf.h b/include/uapi/linux/dma-buf.h index 8e4a2ca0bcbf..46f1e3e98b02 100644 --- a/include/uapi/linux/dma-buf.h +++ b/include/uapi/linux/dma-buf.h @@ -85,6 +85,40 @@ struct dma_buf_sync { #define DMA_BUF_NAME_LEN 32 +/** + * struct dma_buf_export_sync_file - Get a sync_file from a dma-buf + * + * Userspace can perform a DMA_BUF_IOCTL_EXPORT_SYNC_FILE to retrieve the + * current set of fences on a dma-buf file descriptor as a sync_file. CPU + * waits via poll() or other driver-specific mechanisms typically wait on + * whatever fences are on the dma-buf at the time the wait begins. This + * is similar except that it takes a snapshot of the current fences on the + * dma-buf for waiting later instead of waiting immediately. This is + * useful for modern graphics APIs such as Vulkan which assume an explicit + * synchronization model but still need to inter-operate with dma-buf. + */ +struct dma_buf_export_sync_file { + /** + * @flags: Read/write flags + * + * Must be DMA_BUF_SYNC_READ, DMA_BUF_SYNC_WRITE, or both. + * + * If DMA_BUF_SYNC_READ is set and DMA_BUF_SYNC_WRITE is not set, + * the returned sync file waits on any writers of the dma-buf to + * complete. Waiting on the returned sync file is equivalent to + * poll() with POLLIN. + * + * If DMA_BUF_SYNC_WRITE is set, the returned sync file waits on + * any users of the dma-buf (read or write) to complete. Waiting + * on the returned sync file is equivalent to poll() with POLLOUT. + * If both DMA_BUF_SYNC_WRITE and DMA_BUF_SYNC_READ are set, this + * is equivalent to just DMA_BUF_SYNC_WRITE. + */ + __u32 flags; + /** @fd: Returned sync file descriptor */ + __s32 fd; +}; + #define DMA_BUF_BASE 'b' #define DMA_BUF_IOCTL_SYNC _IOW(DMA_BUF_BASE, 0, struct dma_buf_sync) @@ -94,5 +128,6 @@ struct dma_buf_sync { #define DMA_BUF_SET_NAME _IOW(DMA_BUF_BASE, 1, const char *) #define DMA_BUF_SET_NAME_A _IOW(DMA_BUF_BASE, 1, u32) #define DMA_BUF_SET_NAME_B _IOW(DMA_BUF_BASE, 1, u64) +#define DMA_BUF_IOCTL_EXPORT_SYNC_FILE _IOWR(DMA_BUF_BASE, 2, struct dma_buf_export_sync_file) #endif |