| #ifndef _LINUX_PIPE_FS_I_H |
| #define _LINUX_PIPE_FS_I_H |
| |
| #define PIPEFS_MAGIC 0x50495045 |
| |
| #define PIPE_BUFFERS (16) |
| |
| #define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */ |
| #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */ |
| #define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */ |
| |
| struct pipe_buffer { |
| struct page *page; |
| unsigned int offset, len; |
| const struct pipe_buf_operations *ops; |
| unsigned int flags; |
| }; |
| |
| struct pipe_inode_info { |
| wait_queue_head_t wait; |
| unsigned int nrbufs, curbuf; |
| struct page *tmp_page; |
| unsigned int readers; |
| unsigned int writers; |
| unsigned int waiting_writers; |
| unsigned int r_counter; |
| unsigned int w_counter; |
| struct fasync_struct *fasync_readers; |
| struct fasync_struct *fasync_writers; |
| struct inode *inode; |
| struct pipe_buffer bufs[PIPE_BUFFERS]; |
| }; |
| |
| /* |
| * Note on the nesting of these functions: |
| * |
| * ->pin() |
| * ->steal() |
| * ... |
| * ->map() |
| * ... |
| * ->unmap() |
| * |
| * That is, ->map() must be called on a pinned buffer, same goes for ->steal(). |
| */ |
| struct pipe_buf_operations { |
| int can_merge; |
| void * (*map)(struct pipe_inode_info *, struct pipe_buffer *, int); |
| void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *, void *); |
| int (*pin)(struct pipe_inode_info *, struct pipe_buffer *); |
| void (*release)(struct pipe_inode_info *, struct pipe_buffer *); |
| int (*steal)(struct pipe_inode_info *, struct pipe_buffer *); |
| void (*get)(struct pipe_inode_info *, struct pipe_buffer *); |
| }; |
| |
| /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual |
| memory allocation, whereas PIPE_BUF makes atomicity guarantees. */ |
| #define PIPE_SIZE PAGE_SIZE |
| |
| /* Drop the inode semaphore and wait for a pipe event, atomically */ |
| void pipe_wait(struct pipe_inode_info *pipe); |
| |
| struct pipe_inode_info * alloc_pipe_info(struct inode * inode); |
| void free_pipe_info(struct inode * inode); |
| void __free_pipe_info(struct pipe_inode_info *); |
| |
| /* Generic pipe buffer ops functions */ |
| void *generic_pipe_buf_map(struct pipe_inode_info *, struct pipe_buffer *, int); |
| void generic_pipe_buf_unmap(struct pipe_inode_info *, struct pipe_buffer *, void *); |
| void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *); |
| int generic_pipe_buf_pin(struct pipe_inode_info *, struct pipe_buffer *); |
| int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *); |
| |
| #endif |