kbuf.h

  1// SPDX-License-Identifier: GPL-2.0
  2#ifndef IOU_KBUF_H
  3#define IOU_KBUF_H
  4
  5#include <uapi/linux/io_uring.h>
  6#include <linux/io_uring_types.h>
  7
  8enum {
  9	/* ring mapped provided buffers */
 10	IOBL_BUF_RING	= 1,
 11	/* buffers are consumed incrementally rather than always fully */
 12	IOBL_INC	= 2,
 13};
 14
 15struct io_buffer_list {
 16	/*
 17	 * If the IOBL_BUF_RING flag is set, then buf_ring is used. If not, then
 18	 * these are classic provided buffers and ->buf_list is used.
 19	 */
 20	union {
 21		struct list_head buf_list;
 22		struct io_uring_buf_ring *buf_ring;
 23	};
 24	/* count of classic/legacy buffers in buffer list */
 25	int nbufs;
 26
 27	__u16 bgid;
 28
 29	/* below is for ring provided buffers */
 30	__u16 nr_entries;
 31	__u16 head;
 32	__u16 mask;
 33
 34	__u16 flags;
 35
 36	struct io_mapped_region region;
 37};
 38
 39struct io_buffer {
 40	struct list_head list;
 41	__u64 addr;
 42	__u32 len;
 43	__u16 bid;
 44	__u16 bgid;
 45};
 46
 47enum {
 48	/* can alloc a bigger vec */
 49	KBUF_MODE_EXPAND	= 1,
 50	/* if bigger vec allocated, free old one */
 51	KBUF_MODE_FREE		= 2,
 52};
 53
 54struct buf_sel_arg {
 55	struct iovec *iovs;
 56	size_t out_len;
 57	size_t max_len;
 58	unsigned short nr_iovs;
 59	unsigned short mode;
 60	unsigned short buf_group;
 61	unsigned short partial_map;
 62};
 63
 64struct io_br_sel io_buffer_select(struct io_kiocb *req, size_t *len,
 65				  unsigned buf_group, unsigned int issue_flags);
 66int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg,
 67		      struct io_br_sel *sel, unsigned int issue_flags);
 68int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg,
 69		    struct io_br_sel *sel);
 70void io_destroy_buffers(struct io_ring_ctx *ctx);
 71
 72int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
 73int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
 74int io_manage_buffers_legacy(struct io_kiocb *req, unsigned int issue_flags);
 75
 76int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
 77int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
 78int io_register_pbuf_status(struct io_ring_ctx *ctx, void __user *arg);
 79
 80bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags);
 81void io_kbuf_drop_legacy(struct io_kiocb *req);
 82
 83unsigned int __io_put_kbufs(struct io_kiocb *req, struct io_buffer_list *bl,
 84			    int len, int nbufs);
 85bool io_kbuf_commit(struct io_kiocb *req,
 86		    struct io_buffer_list *bl, int len, int nr);
 87
 88struct io_mapped_region *io_pbuf_get_region(struct io_ring_ctx *ctx,
 89					    unsigned int bgid);
 90
 91static inline bool io_kbuf_recycle_ring(struct io_kiocb *req,
 92					struct io_buffer_list *bl)
 93{
 94	if (bl) {
 95		req->flags &= ~(REQ_F_BUFFER_RING|REQ_F_BUFFERS_COMMIT);
 96		return true;
 97	}
 98	return false;
 99}
100
101static inline bool io_do_buffer_select(struct io_kiocb *req)
102{
103	if (!(req->flags & REQ_F_BUFFER_SELECT))
104		return false;
105	return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING));
106}
107
108static inline bool io_kbuf_recycle(struct io_kiocb *req, struct io_buffer_list *bl,
109				   unsigned issue_flags)
110{
111	if (req->flags & REQ_F_BL_NO_RECYCLE)
112		return false;
113	if (req->flags & REQ_F_BUFFER_RING)
114		return io_kbuf_recycle_ring(req, bl);
115	if (req->flags & REQ_F_BUFFER_SELECTED)
116		return io_kbuf_recycle_legacy(req, issue_flags);
117	return false;
118}
119
120static inline unsigned int io_put_kbuf(struct io_kiocb *req, int len,
121				       struct io_buffer_list *bl)
122{
123	if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
124		return 0;
125	return __io_put_kbufs(req, bl, len, 1);
126}
127
128static inline unsigned int io_put_kbufs(struct io_kiocb *req, int len,
129					struct io_buffer_list *bl, int nbufs)
130{
131	if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
132		return 0;
133	return __io_put_kbufs(req, bl, len, nbufs);
134}
135#endif