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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 head;
31 __u16 mask;
32
33 __u16 flags;
34
35 /*
36 * minimum required amount to be left to reuse an incrementally
37 * consumed buffer. If less than this is left at consumption time,
38 * buffer is done and head is incremented to the next buffer.
39 */
40 __u32 min_left_sub_one;
41
42 struct io_mapped_region region;
43};
44
45struct io_buffer {
46 struct list_head list;
47 __u64 addr;
48 __u32 len;
49 __u16 bid;
50 __u16 bgid;
51};
52
53enum {
54 /* can alloc a bigger vec */
55 KBUF_MODE_EXPAND = 1,
56 /* if bigger vec allocated, free old one */
57 KBUF_MODE_FREE = 2,
58};
59
60struct buf_sel_arg {
61 struct iovec *iovs;
62 size_t out_len;
63 size_t max_len;
64 unsigned short nr_iovs;
65 unsigned short mode;
66 unsigned short buf_group;
67 unsigned short partial_map;
68};
69
70struct io_br_sel io_buffer_select(struct io_kiocb *req, size_t *len,
71 unsigned buf_group, unsigned int issue_flags);
72int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg,
73 struct io_br_sel *sel, unsigned int issue_flags);
74int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg,
75 struct io_br_sel *sel);
76void io_destroy_buffers(struct io_ring_ctx *ctx);
77
78int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
79int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
80int io_manage_buffers_legacy(struct io_kiocb *req, unsigned int issue_flags);
81
82int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
83int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
84int io_register_pbuf_status(struct io_ring_ctx *ctx, void __user *arg);
85
86bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags);
87void io_kbuf_drop_legacy(struct io_kiocb *req);
88
89unsigned int __io_put_kbufs(struct io_kiocb *req, struct io_buffer_list *bl,
90 int len, int nbufs);
91bool io_kbuf_commit(struct io_kiocb *req,
92 struct io_buffer_list *bl, int len, int nr);
93
94struct io_mapped_region *io_pbuf_get_region(struct io_ring_ctx *ctx,
95 unsigned int bgid);
96
97static inline bool io_kbuf_recycle_ring(struct io_kiocb *req,
98 struct io_buffer_list *bl)
99{
100 if (bl) {
101 req->flags &= ~(REQ_F_BUFFER_RING|REQ_F_BUFFERS_COMMIT);
102 return true;
103 }
104 return false;
105}
106
107static inline bool io_do_buffer_select(struct io_kiocb *req)
108{
109 if (!(req->flags & REQ_F_BUFFER_SELECT))
110 return false;
111 return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING));
112}
113
114static inline bool io_kbuf_recycle(struct io_kiocb *req, struct io_buffer_list *bl,
115 unsigned issue_flags)
116{
117 if (req->flags & REQ_F_BL_NO_RECYCLE)
118 return false;
119 if (req->flags & REQ_F_BUFFER_RING)
120 return io_kbuf_recycle_ring(req, bl);
121 if (req->flags & REQ_F_BUFFER_SELECTED)
122 return io_kbuf_recycle_legacy(req, issue_flags);
123 return false;
124}
125
126static inline unsigned int io_put_kbuf(struct io_kiocb *req, int len,
127 struct io_buffer_list *bl)
128{
129 if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
130 return 0;
131 return __io_put_kbufs(req, bl, len, 1);
132}
133
134static inline unsigned int io_put_kbufs(struct io_kiocb *req, int len,
135 struct io_buffer_list *bl, int nbufs)
136{
137 if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
138 return 0;
139 return __io_put_kbufs(req, bl, len, nbufs);
140}
141#endif