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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 | ||
7 | struct io_buffer_list { | |
8 | /* | |
9 | * If ->buf_nr_pages is set, then buf_pages/buf_ring are used. If not, | |
10 | * then these are classic provided buffers and ->buf_list is used. | |
11 | */ | |
12 | union { | |
13 | struct list_head buf_list; | |
14 | struct { | |
15 | struct page **buf_pages; | |
16 | struct io_uring_buf_ring *buf_ring; | |
17 | }; | |
5cf4f52e | 18 | struct rcu_head rcu; |
3b77495a JA |
19 | }; |
20 | __u16 bgid; | |
21 | ||
22 | /* below is for ring provided buffers */ | |
23 | __u16 buf_nr_pages; | |
24 | __u16 nr_entries; | |
25 | __u16 head; | |
26 | __u16 mask; | |
25a2c188 JA |
27 | |
28 | /* ring mapped provided buffers */ | |
29 | __u8 is_mapped; | |
c56e022c JA |
30 | /* ring mapped provided buffers, but mmap'ed by application */ |
31 | __u8 is_mmap; | |
5cf4f52e JA |
32 | /* bl is visible from an RCU point of view for lookup */ |
33 | __u8 is_ready; | |
3b77495a JA |
34 | }; |
35 | ||
36 | struct io_buffer { | |
37 | struct list_head list; | |
38 | __u64 addr; | |
39 | __u32 len; | |
40 | __u16 bid; | |
41 | __u16 bgid; | |
42 | }; | |
43 | ||
44 | void __user *io_buffer_select(struct io_kiocb *req, size_t *len, | |
45 | unsigned int issue_flags); | |
3b77495a JA |
46 | void io_destroy_buffers(struct io_ring_ctx *ctx); |
47 | ||
48 | int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); | |
49 | int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags); | |
50 | ||
51 | int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); | |
52 | int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags); | |
53 | ||
54 | int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); | |
55 | int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); | |
56 | ||
c392cbec JA |
57 | void io_kbuf_mmap_list_free(struct io_ring_ctx *ctx); |
58 | ||
53ccf69b PB |
59 | unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags); |
60 | ||
89d528ba | 61 | bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags); |
795bbbc8 | 62 | |
c56e022c JA |
63 | void *io_pbuf_get_address(struct io_ring_ctx *ctx, unsigned long bgid); |
64 | ||
89d528ba | 65 | static inline bool io_kbuf_recycle_ring(struct io_kiocb *req) |
795bbbc8 HX |
66 | { |
67 | /* | |
68 | * We don't need to recycle for REQ_F_BUFFER_RING, we can just clear | |
69 | * the flag and hence ensure that bl->head doesn't get incremented. | |
70 | * If the tail has already been incremented, hang on to it. | |
71 | * The exception is partial io, that case we should increment bl->head | |
72 | * to monopolize the buffer. | |
73 | */ | |
74 | if (req->buf_list) { | |
75 | if (req->flags & REQ_F_PARTIAL_IO) { | |
76 | /* | |
77 | * If we end up here, then the io_uring_lock has | |
78 | * been kept held since we retrieved the buffer. | |
79 | * For the io-wq case, we already cleared | |
80 | * req->buf_list when the buffer was retrieved, | |
81 | * hence it cannot be set here for that case. | |
82 | */ | |
83 | req->buf_list->head++; | |
84 | req->buf_list = NULL; | |
85 | } else { | |
86 | req->buf_index = req->buf_list->bgid; | |
87 | req->flags &= ~REQ_F_BUFFER_RING; | |
89d528ba | 88 | return true; |
795bbbc8 HX |
89 | } |
90 | } | |
89d528ba | 91 | return false; |
795bbbc8 | 92 | } |
024b8fde | 93 | |
3b77495a JA |
94 | static inline bool io_do_buffer_select(struct io_kiocb *req) |
95 | { | |
96 | if (!(req->flags & REQ_F_BUFFER_SELECT)) | |
97 | return false; | |
98 | return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)); | |
99 | } | |
100 | ||
89d528ba | 101 | static inline bool io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags) |
3b77495a | 102 | { |
024b8fde | 103 | if (req->flags & REQ_F_BUFFER_SELECTED) |
89d528ba | 104 | return io_kbuf_recycle_legacy(req, issue_flags); |
024b8fde | 105 | if (req->flags & REQ_F_BUFFER_RING) |
89d528ba DY |
106 | return io_kbuf_recycle_ring(req); |
107 | return false; | |
3b77495a JA |
108 | } |
109 | ||
53ccf69b PB |
110 | static inline unsigned int __io_put_kbuf_list(struct io_kiocb *req, |
111 | struct list_head *list) | |
3b77495a | 112 | { |
32f3c434 DY |
113 | unsigned int ret = IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT); |
114 | ||
3b77495a | 115 | if (req->flags & REQ_F_BUFFER_RING) { |
32f3c434 DY |
116 | if (req->buf_list) { |
117 | req->buf_index = req->buf_list->bgid; | |
3b77495a | 118 | req->buf_list->head++; |
32f3c434 | 119 | } |
3b77495a JA |
120 | req->flags &= ~REQ_F_BUFFER_RING; |
121 | } else { | |
32f3c434 | 122 | req->buf_index = req->kbuf->bgid; |
3b77495a JA |
123 | list_add(&req->kbuf->list, list); |
124 | req->flags &= ~REQ_F_BUFFER_SELECTED; | |
125 | } | |
126 | ||
32f3c434 | 127 | return ret; |
3b77495a JA |
128 | } |
129 | ||
130 | static inline unsigned int io_put_kbuf_comp(struct io_kiocb *req) | |
131 | { | |
132 | lockdep_assert_held(&req->ctx->completion_lock); | |
133 | ||
134 | if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING))) | |
135 | return 0; | |
53ccf69b | 136 | return __io_put_kbuf_list(req, &req->ctx->io_buffers_comp); |
3b77495a JA |
137 | } |
138 | ||
139 | static inline unsigned int io_put_kbuf(struct io_kiocb *req, | |
140 | unsigned issue_flags) | |
141 | { | |
3b77495a JA |
142 | |
143 | if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING))) | |
144 | return 0; | |
53ccf69b | 145 | return __io_put_kbuf(req, issue_flags); |
3b77495a JA |
146 | } |
147 | #endif |