linux-4.4.1/vb2_mem_ops の履歴(No.2)

• 履歴一覧
• 差分 を表示
• 現在との差分 を表示
• ソース を表示
• linux-4.4.1/vb2_mem_ops へ行く。
  • 1 (2016-02-08 (月) 11:05:55)
  • 2 (2016-02-08 (月) 11:13:51)

参照元†

• linux-4.4.1/__vb2_buf_mem_alloc()
• linux-4.4.1/call_ptr_memop()
• linux-4.4.1/vb2_core_expbuf()
• linux-4.4.1/vb2_dma_contig_memops(global)
• linux-4.4.1/vb2_dma_sg_memops(global)
• linux-4.4.1/vb2_queue
• linux-4.4.1/vb2_vmalloc_memops(global)

説明†

• パス: linux-4.4.1/include/media/videobuf2-core.h

• FIXME: これは何？
  • 説明

参考†

実装†

/**
 * struct vb2_mem_ops - memory handling/memory allocator operations
 * @alloc:      allocate video memory and, optionally, allocator private data,
 *              return NULL on failure or a pointer to allocator private,
 *              per-buffer data on success; the returned private structure
 *              will then be passed as buf_priv argument to other ops in this
 *              structure. Additional gfp_flags to use when allocating the
 *              are also passed to this operation. These flags are from the
 *              gfp_flags field of vb2_queue.
 * @put:        inform the allocator that the buffer will no longer be used;
 *              usually will result in the allocator freeing the buffer (if
 *              no other users of this buffer are present); the buf_priv
 *              argument is the allocator private per-buffer structure
 *              previously returned from the alloc callback.
 * @get_dmabuf: acquire userspace memory for a hardware operation; used for
 *               DMABUF memory types.
 * @get_userptr: acquire userspace memory for a hardware operation; used for
 *               USERPTR memory types; vaddr is the address passed to the
 *               videobuf layer when queuing a video buffer of USERPTR type;
 *               should return an allocator private per-buffer structure
 *               associated with the buffer on success, NULL on failure;
 *               the returned private structure will then be passed as buf_priv
 *               argument to other ops in this structure.
 * @put_userptr: inform the allocator that a USERPTR buffer will no longer
 *               be used.
 * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
 *                 used for DMABUF memory types; alloc_ctx is the alloc context
 *                 dbuf is the shared dma_buf; returns NULL on failure;
 *                 allocator private per-buffer structure on success;
 *                 this needs to be used for further accesses to the buffer.
 * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
 *                 buffer is no longer used; the buf_priv argument is the
 *                 allocator private per-buffer structure previously returned
 *                 from the attach_dmabuf callback.
 * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
 *              of dmabuf is informed that this driver is going to use the
 *              dmabuf.
 * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
 *                that this driver is done using the dmabuf for now.
 * @prepare:    called every time the buffer is passed from userspace to the
 *              driver, useful for cache synchronisation, optional.
 * @finish:     called every time the buffer is passed back from the driver
 *              to the userspace, also optional.
 * @vaddr:      return a kernel virtual address to a given memory buffer
 *              associated with the passed private structure or NULL if no
 *              such mapping exists.
 * @cookie:     return allocator specific cookie for a given memory buffer
 *              associated with the passed private structure or NULL if not
 *              available.
 * @num_users:  return the current number of users of a memory buffer;
 *              return 1 if the videobuf layer (or actually the driver using
 *              it) is the only user.
 * @mmap:       setup a userspace mapping for a given memory buffer under
 *              the provided virtual memory region.
 *
 * Required ops for USERPTR types: get_userptr, put_userptr.
 * Required ops for MMAP types: alloc, put, num_users, mmap.
 * Required ops for read/write access types: alloc, put, num_users, vaddr.
 * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf,
 *                                unmap_dmabuf.
 */
struct vb2_mem_ops {
        void            *(*alloc)(void *alloc_ctx, unsigned long size,
                                  enum dma_data_direction dma_dir,
                                  gfp_t gfp_flags);

• • linux-4.4.1/dma_data_direction
  • linux-4.4.1/gfp_t

        void            (*put)(void *buf_priv);
        struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);

• • linux-4.4.1/dma_buf

        void            *(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
                                        unsigned long size,
                                        enum dma_data_direction dma_dir);
        void            (*put_userptr)(void *buf_priv);

        void            (*prepare)(void *buf_priv);
        void            (*finish)(void *buf_priv);

        void            *(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
                                          unsigned long size,
                                          enum dma_data_direction dma_dir);
        void            (*detach_dmabuf)(void *buf_priv);
        int             (*map_dmabuf)(void *buf_priv);
        void            (*unmap_dmabuf)(void *buf_priv);

        void            *(*vaddr)(void *buf_priv);
        void            *(*cookie)(void *buf_priv);

        unsigned int    (*num_users)(void *buf_priv);

        int             (*mmap)(void *buf_priv, struct vm_area_struct *vma);

• • linux-4.4.1/vm_area_struct

};

コメント†