Linux kernel mirror (for testing)
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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