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 8 enum { 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 15 struct 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 40 struct io_buffer { 41 struct list_head list; 42 __u64 addr; 43 __u32 len; 44 __u16 bid; 45 __u16 bgid; 46 }; 47 48 enum { 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 55 struct 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 buf_group; 62 }; 63 64 void __user *io_buffer_select(struct io_kiocb *req, size_t *len, 65 unsigned buf_group, unsigned int issue_flags); 66 int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg, 67 unsigned int issue_flags); 68 int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg); 69 void io_destroy_buffers(struct io_ring_ctx *ctx); 70 71 int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); 72 int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); 73 int io_manage_buffers_legacy(struct io_kiocb *req, unsigned int issue_flags); 74 75 int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); 76 int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); 77 int io_register_pbuf_status(struct io_ring_ctx *ctx, void __user *arg); 78 79 bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags); 80 void io_kbuf_drop_legacy(struct io_kiocb *req); 81 82 unsigned int __io_put_kbufs(struct io_kiocb *req, int len, int nbufs); 83 bool io_kbuf_commit(struct io_kiocb *req, 84 struct io_buffer_list *bl, int len, int nr); 85 86 struct io_mapped_region *io_pbuf_get_region(struct io_ring_ctx *ctx, 87 unsigned int bgid); 88 89 static inline bool io_kbuf_recycle_ring(struct io_kiocb *req) 90 { 91 /* 92 * We don't need to recycle for REQ_F_BUFFER_RING, we can just clear 93 * the flag and hence ensure that bl->head doesn't get incremented. 94 * If the tail has already been incremented, hang on to it. 95 * The exception is partial io, that case we should increment bl->head 96 * to monopolize the buffer. 97 */ 98 if (req->buf_list) { 99 req->flags &= ~(REQ_F_BUFFER_RING|REQ_F_BUFFERS_COMMIT); 100 return true; 101 } 102 return false; 103 } 104 105 static inline bool io_do_buffer_select(struct io_kiocb *req) 106 { 107 if (!(req->flags & REQ_F_BUFFER_SELECT)) 108 return false; 109 return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)); 110 } 111 112 static inline bool io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags) 113 { 114 if (req->flags & REQ_F_BL_NO_RECYCLE) 115 return false; 116 if (req->flags & REQ_F_BUFFER_SELECTED) 117 return io_kbuf_recycle_legacy(req, issue_flags); 118 if (req->flags & REQ_F_BUFFER_RING) 119 return io_kbuf_recycle_ring(req); 120 return false; 121 } 122 123 static inline unsigned int io_put_kbuf(struct io_kiocb *req, int len, 124 unsigned issue_flags) 125 { 126 if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED))) 127 return 0; 128 return __io_put_kbufs(req, len, 1); 129 } 130 131 static inline unsigned int io_put_kbufs(struct io_kiocb *req, int len, 132 int nbufs, unsigned issue_flags) 133 { 134 if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED))) 135 return 0; 136 return __io_put_kbufs(req, len, nbufs); 137 } 138 #endif 139