diff options
Diffstat (limited to 'include/linux/dma-buf.h')
| -rw-r--r-- | include/linux/dma-buf.h | 65 |
1 files changed, 43 insertions, 22 deletions
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 58725f890b5b..bae060fae862 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Header file for dma buffer sharing framework. * @@ -8,18 +9,6 @@ * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and * Daniel Vetter <daniel@ffwll.ch> for their support in creation and * refining of this idea. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published by - * the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program. If not, see <http://www.gnu.org/licenses/>. */ #ifndef __DMA_BUF_H__ #define __DMA_BUF_H__ @@ -39,19 +28,21 @@ struct dma_buf_attachment; /** * struct dma_buf_ops - operations possible on struct dma_buf - * @map_atomic: [optional] maps a page from the buffer into kernel address - * space, users may not block until the subsequent unmap call. - * This callback must not sleep. - * @unmap_atomic: [optional] unmaps a atomically mapped page from the buffer. - * This Callback must not sleep. - * @map: [optional] maps a page from the buffer into kernel address space. - * @unmap: [optional] unmaps a page from the buffer. * @vmap: [optional] creates a virtual mapping for the buffer into kernel * address space. Same restrictions as for vmap and friends apply. * @vunmap: [optional] unmaps a vmap from the buffer */ struct dma_buf_ops { /** + * @cache_sgt_mapping: + * + * If true the framework will cache the first mapping made for each + * attachment. This avoids creating mappings for attachments multiple + * times. + */ + bool cache_sgt_mapping; + + /** * @attach: * * This is called from dma_buf_attach() to make sure that a given @@ -205,8 +196,6 @@ struct dma_buf_ops { * to be restarted. */ int (*end_cpu_access)(struct dma_buf *, enum dma_data_direction); - void *(*map)(struct dma_buf *, unsigned long); - void (*unmap)(struct dma_buf *, unsigned long, void *); /** * @mmap: @@ -245,6 +234,31 @@ struct dma_buf_ops { */ int (*mmap)(struct dma_buf *, struct vm_area_struct *vma); + /** + * @map: + * + * Maps a page from the buffer into kernel address space. The page is + * specified by offset into the buffer in PAGE_SIZE units. + * + * This callback is optional. + * + * Returns: + * + * Virtual address pointer where requested page can be accessed. NULL + * on error or when this function is unimplemented by the exporter. + */ + void *(*map)(struct dma_buf *, unsigned long); + + /** + * @unmap: + * + * Unmaps a page from the buffer. Page offset and address pointer should + * be the same as the one passed to and returned by matching call to map. + * + * This callback is optional. + */ + void (*unmap)(struct dma_buf *, unsigned long, void *); + void *(*vmap)(struct dma_buf *); void (*vunmap)(struct dma_buf *, void *vaddr); }; @@ -255,10 +269,12 @@ struct dma_buf_ops { * @file: file pointer used for sharing buffers across, and for refcounting. * @attachments: list of dma_buf_attachment that denotes all devices attached. * @ops: dma_buf_ops associated with this buffer object. - * @lock: used internally to serialize list manipulation, attach/detach and vmap/unmap + * @lock: used internally to serialize list manipulation, attach/detach and + * vmap/unmap, and accesses to name * @vmapping_counter: used internally to refcnt the vmaps * @vmap_ptr: the current vmap ptr if vmapping_counter > 0 * @exp_name: name of the exporter; useful for debugging. + * @name: userspace-provided name; useful for accounting and debugging. * @owner: pointer to exporter module; used for refcounting when exporter is a * kernel module. * @list_node: node for dma_buf accounting and debugging. @@ -286,6 +302,7 @@ struct dma_buf { unsigned vmapping_counter; void *vmap_ptr; const char *exp_name; + const char *name; struct module *owner; struct list_head list_node; void *priv; @@ -307,6 +324,8 @@ struct dma_buf { * @dmabuf: buffer for this attachment. * @dev: device attached to the buffer. * @node: list of dma_buf_attachment. + * @sgt: cached mapping. + * @dir: direction of cached mapping. * @priv: exporter specific attachment data. * * This structure holds the attachment information between the dma_buf buffer @@ -322,6 +341,8 @@ struct dma_buf_attachment { struct dma_buf *dmabuf; struct device *dev; struct list_head node; + struct sg_table *sgt; + enum dma_data_direction dir; void *priv; }; |