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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
;
22 /* below is for ring provided buffers */
28 /* ring mapped provided buffers */
30 /* ring mapped provided buffers, but mmap'ed by application */
32 /* bl is visible from an RCU point of view for lookup */
37 struct list_head list
;
44 void __user
*io_buffer_select(struct io_kiocb
*req
, size_t *len
,
45 unsigned int issue_flags
);
46 void io_destroy_buffers(struct io_ring_ctx
*ctx
);
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
);
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
);
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 int io_register_pbuf_status(struct io_ring_ctx
*ctx
, void __user
*arg
);
58 void io_kbuf_mmap_list_free(struct io_ring_ctx
*ctx
);
60 unsigned int __io_put_kbuf(struct io_kiocb
*req
, unsigned issue_flags
);
62 bool io_kbuf_recycle_legacy(struct io_kiocb
*req
, unsigned issue_flags
);
64 void *io_pbuf_get_address(struct io_ring_ctx
*ctx
, unsigned long bgid
);
66 static inline bool io_kbuf_recycle_ring(struct io_kiocb
*req
)
69 * We don't need to recycle for REQ_F_BUFFER_RING, we can just clear
70 * the flag and hence ensure that bl->head doesn't get incremented.
71 * If the tail has already been incremented, hang on to it.
72 * The exception is partial io, that case we should increment bl->head
73 * to monopolize the buffer.
76 if (req
->flags
& REQ_F_PARTIAL_IO
) {
78 * If we end up here, then the io_uring_lock has
79 * been kept held since we retrieved the buffer.
80 * For the io-wq case, we already cleared
81 * req->buf_list when the buffer was retrieved,
82 * hence it cannot be set here for that case.
84 req
->buf_list
->head
++;
87 req
->buf_index
= req
->buf_list
->bgid
;
88 req
->flags
&= ~REQ_F_BUFFER_RING
;
95 static inline bool io_do_buffer_select(struct io_kiocb
*req
)
97 if (!(req
->flags
& REQ_F_BUFFER_SELECT
))
99 return !(req
->flags
& (REQ_F_BUFFER_SELECTED
|REQ_F_BUFFER_RING
));
102 static inline bool io_kbuf_recycle(struct io_kiocb
*req
, unsigned issue_flags
)
104 if (req
->flags
& REQ_F_BUFFER_SELECTED
)
105 return io_kbuf_recycle_legacy(req
, issue_flags
);
106 if (req
->flags
& REQ_F_BUFFER_RING
)
107 return io_kbuf_recycle_ring(req
);
111 static inline unsigned int __io_put_kbuf_list(struct io_kiocb
*req
,
112 struct list_head
*list
)
114 unsigned int ret
= IORING_CQE_F_BUFFER
| (req
->buf_index
<< IORING_CQE_BUFFER_SHIFT
);
116 if (req
->flags
& REQ_F_BUFFER_RING
) {
118 req
->buf_index
= req
->buf_list
->bgid
;
119 req
->buf_list
->head
++;
121 req
->flags
&= ~REQ_F_BUFFER_RING
;
123 req
->buf_index
= req
->kbuf
->bgid
;
124 list_add(&req
->kbuf
->list
, list
);
125 req
->flags
&= ~REQ_F_BUFFER_SELECTED
;
131 static inline unsigned int io_put_kbuf_comp(struct io_kiocb
*req
)
133 lockdep_assert_held(&req
->ctx
->completion_lock
);
135 if (!(req
->flags
& (REQ_F_BUFFER_SELECTED
|REQ_F_BUFFER_RING
)))
137 return __io_put_kbuf_list(req
, &req
->ctx
->io_buffers_comp
);
140 static inline unsigned int io_put_kbuf(struct io_kiocb
*req
,
141 unsigned issue_flags
)
144 if (!(req
->flags
& (REQ_F_BUFFER_SELECTED
|REQ_F_BUFFER_RING
)))
146 return __io_put_kbuf(req
, issue_flags
);