Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 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 | }; |
| 18 | }; |
| 19 | __u16 bgid; |
| 20 | |
| 21 | /* below is for ring provided buffers */ |
| 22 | __u16 buf_nr_pages; |
| 23 | __u16 nr_entries; |
| 24 | __u16 head; |
| 25 | __u16 mask; |
| 26 | }; |
| 27 | |
| 28 | struct io_buffer { |
| 29 | struct list_head list; |
| 30 | __u64 addr; |
| 31 | __u32 len; |
| 32 | __u16 bid; |
| 33 | __u16 bgid; |
| 34 | }; |
| 35 | |
| 36 | void __user *io_buffer_select(struct io_kiocb *req, size_t *len, |
| 37 | unsigned int issue_flags); |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 38 | void io_destroy_buffers(struct io_ring_ctx *ctx); |
| 39 | |
| 40 | int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); |
| 41 | int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags); |
| 42 | |
| 43 | int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); |
| 44 | int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags); |
| 45 | |
| 46 | int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); |
| 47 | int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); |
| 48 | |
Pavel Begunkov | 53ccf69 | 2022-06-16 10:22:00 +0100 | [diff] [blame] | 49 | unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags); |
| 50 | |
Hao Xu | 024b8fd | 2022-06-22 13:55:51 +0800 | [diff] [blame] | 51 | void io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags); |
Hao Xu | 795bbbc | 2022-06-23 21:01:26 +0800 | [diff] [blame] | 52 | |
| 53 | static inline void io_kbuf_recycle_ring(struct io_kiocb *req) |
| 54 | { |
| 55 | /* |
| 56 | * We don't need to recycle for REQ_F_BUFFER_RING, we can just clear |
| 57 | * the flag and hence ensure that bl->head doesn't get incremented. |
| 58 | * If the tail has already been incremented, hang on to it. |
| 59 | * The exception is partial io, that case we should increment bl->head |
| 60 | * to monopolize the buffer. |
| 61 | */ |
| 62 | if (req->buf_list) { |
| 63 | if (req->flags & REQ_F_PARTIAL_IO) { |
| 64 | /* |
| 65 | * If we end up here, then the io_uring_lock has |
| 66 | * been kept held since we retrieved the buffer. |
| 67 | * For the io-wq case, we already cleared |
| 68 | * req->buf_list when the buffer was retrieved, |
| 69 | * hence it cannot be set here for that case. |
| 70 | */ |
| 71 | req->buf_list->head++; |
| 72 | req->buf_list = NULL; |
| 73 | } else { |
| 74 | req->buf_index = req->buf_list->bgid; |
| 75 | req->flags &= ~REQ_F_BUFFER_RING; |
| 76 | } |
| 77 | } |
| 78 | } |
Hao Xu | 024b8fd | 2022-06-22 13:55:51 +0800 | [diff] [blame] | 79 | |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 80 | static inline bool io_do_buffer_select(struct io_kiocb *req) |
| 81 | { |
| 82 | if (!(req->flags & REQ_F_BUFFER_SELECT)) |
| 83 | return false; |
| 84 | return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)); |
| 85 | } |
| 86 | |
| 87 | static inline void io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags) |
| 88 | { |
Hao Xu | 024b8fd | 2022-06-22 13:55:51 +0800 | [diff] [blame] | 89 | if (req->flags & REQ_F_BUFFER_SELECTED) |
| 90 | io_kbuf_recycle_legacy(req, issue_flags); |
| 91 | if (req->flags & REQ_F_BUFFER_RING) |
| 92 | io_kbuf_recycle_ring(req); |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 93 | } |
| 94 | |
Pavel Begunkov | 53ccf69 | 2022-06-16 10:22:00 +0100 | [diff] [blame] | 95 | static inline unsigned int __io_put_kbuf_list(struct io_kiocb *req, |
| 96 | struct list_head *list) |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 97 | { |
Dylan Yudaken | 32f3c43 | 2022-06-30 02:12:21 -0700 | [diff] [blame] | 98 | unsigned int ret = IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT); |
| 99 | |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 100 | if (req->flags & REQ_F_BUFFER_RING) { |
Dylan Yudaken | 32f3c43 | 2022-06-30 02:12:21 -0700 | [diff] [blame] | 101 | if (req->buf_list) { |
| 102 | req->buf_index = req->buf_list->bgid; |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 103 | req->buf_list->head++; |
Dylan Yudaken | 32f3c43 | 2022-06-30 02:12:21 -0700 | [diff] [blame] | 104 | } |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 105 | req->flags &= ~REQ_F_BUFFER_RING; |
| 106 | } else { |
Dylan Yudaken | 32f3c43 | 2022-06-30 02:12:21 -0700 | [diff] [blame] | 107 | req->buf_index = req->kbuf->bgid; |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 108 | list_add(&req->kbuf->list, list); |
| 109 | req->flags &= ~REQ_F_BUFFER_SELECTED; |
| 110 | } |
| 111 | |
Dylan Yudaken | 32f3c43 | 2022-06-30 02:12:21 -0700 | [diff] [blame] | 112 | return ret; |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 113 | } |
| 114 | |
| 115 | static inline unsigned int io_put_kbuf_comp(struct io_kiocb *req) |
| 116 | { |
| 117 | lockdep_assert_held(&req->ctx->completion_lock); |
| 118 | |
| 119 | if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING))) |
| 120 | return 0; |
Pavel Begunkov | 53ccf69 | 2022-06-16 10:22:00 +0100 | [diff] [blame] | 121 | return __io_put_kbuf_list(req, &req->ctx->io_buffers_comp); |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 122 | } |
| 123 | |
| 124 | static inline unsigned int io_put_kbuf(struct io_kiocb *req, |
| 125 | unsigned issue_flags) |
| 126 | { |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 127 | |
| 128 | if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING))) |
| 129 | return 0; |
Pavel Begunkov | 53ccf69 | 2022-06-16 10:22:00 +0100 | [diff] [blame] | 130 | return __io_put_kbuf(req, issue_flags); |
Jens Axboe | 3b77495 | 2022-06-13 07:07:23 -0600 | [diff] [blame] | 131 | } |
| 132 | #endif |