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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 ->buf_nr_pages is set, then buf_pages/buf_ring are used. If not,
18 * then 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 buf_nr_pages;
31 __u16 nr_entries;
32 __u16 head;
33 __u16 mask;
34
35 __u16 flags;
36
37 struct io_mapped_region region;
38};
39
40struct io_buffer {
41 struct list_head list;
42 __u64 addr;
43 __u32 len;
44 __u16 bid;
45 __u16 bgid;
46};
47
48enum {
49 /* can alloc a bigger vec */
50 KBUF_MODE_EXPAND = 1,
51 /* if bigger vec allocated, free old one */
52 KBUF_MODE_FREE = 2,
53};
54
55struct buf_sel_arg {
56 struct iovec *iovs;
57 size_t out_len;
58 size_t max_len;
59 unsigned short nr_iovs;
60 unsigned short mode;
61 unsigned short buf_group;
62 unsigned short partial_map;
63};
64
65void __user *io_buffer_select(struct io_kiocb *req, size_t *len,
66 unsigned buf_group, unsigned int issue_flags);
67int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg,
68 unsigned int issue_flags);
69int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg);
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, int len, int nbufs);
84bool io_kbuf_commit(struct io_kiocb *req,
85 struct io_buffer_list *bl, int len, int nr);
86
87struct io_mapped_region *io_pbuf_get_region(struct io_ring_ctx *ctx,
88 unsigned int bgid);
89
90static inline bool io_kbuf_recycle_ring(struct io_kiocb *req)
91{
92 /*
93 * We don't need to recycle for REQ_F_BUFFER_RING, we can just clear
94 * the flag and hence ensure that bl->head doesn't get incremented.
95 * If the tail has already been incremented, hang on to it.
96 * The exception is partial io, that case we should increment bl->head
97 * to monopolize the buffer.
98 */
99 if (req->buf_list) {
100 req->flags &= ~(REQ_F_BUFFER_RING|REQ_F_BUFFERS_COMMIT);
101 return true;
102 }
103 return false;
104}
105
106static inline bool io_do_buffer_select(struct io_kiocb *req)
107{
108 if (!(req->flags & REQ_F_BUFFER_SELECT))
109 return false;
110 return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING));
111}
112
113static inline bool io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
114{
115 if (req->flags & REQ_F_BL_NO_RECYCLE)
116 return false;
117 if (req->flags & REQ_F_BUFFER_SELECTED)
118 return io_kbuf_recycle_legacy(req, issue_flags);
119 if (req->flags & REQ_F_BUFFER_RING)
120 return io_kbuf_recycle_ring(req);
121 return false;
122}
123
124static inline unsigned int io_put_kbuf(struct io_kiocb *req, int len,
125 unsigned issue_flags)
126{
127 if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
128 return 0;
129 return __io_put_kbufs(req, len, 1);
130}
131
132static inline unsigned int io_put_kbufs(struct io_kiocb *req, int len,
133 int nbufs, unsigned issue_flags)
134{
135 if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
136 return 0;
137 return __io_put_kbufs(req, len, nbufs);
138}
139#endif