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git.ipfire.org Git - thirdparty/linux.git/blob - io_uring/kbuf.h
1 // SPDX-License-Identifier: GPL-2.0
5 #include <uapi/linux/io_uring.h>
7 struct io_buffer_list
{
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.
13 struct list_head buf_list
;
15 struct page
**buf_pages
;
16 struct io_uring_buf_ring
*buf_ring
;
21 /* below is for ring provided buffers */
27 /* ring mapped provided buffers */
29 /* ring mapped provided buffers, but mmap'ed by application */
34 struct list_head list
;
41 void __user
*io_buffer_select(struct io_kiocb
*req
, size_t *len
,
42 unsigned int issue_flags
);
43 void io_destroy_buffers(struct io_ring_ctx
*ctx
);
45 int io_remove_buffers_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
);
46 int io_remove_buffers(struct io_kiocb
*req
, unsigned int issue_flags
);
48 int io_provide_buffers_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
);
49 int io_provide_buffers(struct io_kiocb
*req
, unsigned int issue_flags
);
51 int io_register_pbuf_ring(struct io_ring_ctx
*ctx
, void __user
*arg
);
52 int io_unregister_pbuf_ring(struct io_ring_ctx
*ctx
, void __user
*arg
);
54 unsigned int __io_put_kbuf(struct io_kiocb
*req
, unsigned issue_flags
);
56 void io_kbuf_recycle_legacy(struct io_kiocb
*req
, unsigned issue_flags
);
58 void *io_pbuf_get_address(struct io_ring_ctx
*ctx
, unsigned long bgid
);
60 static inline void io_kbuf_recycle_ring(struct io_kiocb
*req
)
63 * We don't need to recycle for REQ_F_BUFFER_RING, we can just clear
64 * the flag and hence ensure that bl->head doesn't get incremented.
65 * If the tail has already been incremented, hang on to it.
66 * The exception is partial io, that case we should increment bl->head
67 * to monopolize the buffer.
70 if (req
->flags
& REQ_F_PARTIAL_IO
) {
72 * If we end up here, then the io_uring_lock has
73 * been kept held since we retrieved the buffer.
74 * For the io-wq case, we already cleared
75 * req->buf_list when the buffer was retrieved,
76 * hence it cannot be set here for that case.
78 req
->buf_list
->head
++;
81 req
->buf_index
= req
->buf_list
->bgid
;
82 req
->flags
&= ~REQ_F_BUFFER_RING
;
87 static inline bool io_do_buffer_select(struct io_kiocb
*req
)
89 if (!(req
->flags
& REQ_F_BUFFER_SELECT
))
91 return !(req
->flags
& (REQ_F_BUFFER_SELECTED
|REQ_F_BUFFER_RING
));
94 static inline void io_kbuf_recycle(struct io_kiocb
*req
, unsigned issue_flags
)
96 if (req
->flags
& REQ_F_BUFFER_SELECTED
)
97 io_kbuf_recycle_legacy(req
, issue_flags
);
98 if (req
->flags
& REQ_F_BUFFER_RING
)
99 io_kbuf_recycle_ring(req
);
102 static inline unsigned int __io_put_kbuf_list(struct io_kiocb
*req
,
103 struct list_head
*list
)
105 unsigned int ret
= IORING_CQE_F_BUFFER
| (req
->buf_index
<< IORING_CQE_BUFFER_SHIFT
);
107 if (req
->flags
& REQ_F_BUFFER_RING
) {
109 req
->buf_index
= req
->buf_list
->bgid
;
110 req
->buf_list
->head
++;
112 req
->flags
&= ~REQ_F_BUFFER_RING
;
114 req
->buf_index
= req
->kbuf
->bgid
;
115 list_add(&req
->kbuf
->list
, list
);
116 req
->flags
&= ~REQ_F_BUFFER_SELECTED
;
122 static inline unsigned int io_put_kbuf_comp(struct io_kiocb
*req
)
124 lockdep_assert_held(&req
->ctx
->completion_lock
);
126 if (!(req
->flags
& (REQ_F_BUFFER_SELECTED
|REQ_F_BUFFER_RING
)))
128 return __io_put_kbuf_list(req
, &req
->ctx
->io_buffers_comp
);
131 static inline unsigned int io_put_kbuf(struct io_kiocb
*req
,
132 unsigned issue_flags
)
135 if (!(req
->flags
& (REQ_F_BUFFER_SELECTED
|REQ_F_BUFFER_RING
)))
137 return __io_put_kbuf(req
, issue_flags
);