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132 lines
3.6 KiB
132 lines
3.6 KiB
// SPDX-License-Identifier: GPL-2.0 |
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#ifndef IOU_KBUF_H |
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#define IOU_KBUF_H |
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#include <uapi/linux/io_uring.h> |
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struct io_buffer_list { |
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/* |
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* If ->buf_nr_pages is set, then buf_pages/buf_ring are used. If not, |
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* then these are classic provided buffers and ->buf_list is used. |
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*/ |
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union { |
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struct list_head buf_list; |
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struct { |
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struct page **buf_pages; |
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struct io_uring_buf_ring *buf_ring; |
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}; |
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}; |
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__u16 bgid; |
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/* below is for ring provided buffers */ |
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__u16 buf_nr_pages; |
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__u16 nr_entries; |
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__u16 head; |
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__u16 mask; |
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}; |
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struct io_buffer { |
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struct list_head list; |
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__u64 addr; |
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__u32 len; |
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__u16 bid; |
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__u16 bgid; |
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}; |
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void __user *io_buffer_select(struct io_kiocb *req, size_t *len, |
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unsigned int issue_flags); |
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void io_destroy_buffers(struct io_ring_ctx *ctx); |
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int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); |
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int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags); |
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int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe); |
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int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags); |
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int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); |
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int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg); |
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unsigned int __io_put_kbuf(struct io_kiocb *req, unsigned issue_flags); |
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void io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags); |
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static inline void io_kbuf_recycle_ring(struct io_kiocb *req) |
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{ |
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/* |
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* We don't need to recycle for REQ_F_BUFFER_RING, we can just clear |
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* the flag and hence ensure that bl->head doesn't get incremented. |
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* If the tail has already been incremented, hang on to it. |
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* The exception is partial io, that case we should increment bl->head |
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* to monopolize the buffer. |
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*/ |
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if (req->buf_list) { |
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if (req->flags & REQ_F_PARTIAL_IO) { |
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/* |
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* If we end up here, then the io_uring_lock has |
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* been kept held since we retrieved the buffer. |
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* For the io-wq case, we already cleared |
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* req->buf_list when the buffer was retrieved, |
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* hence it cannot be set here for that case. |
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*/ |
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req->buf_list->head++; |
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req->buf_list = NULL; |
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} else { |
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req->buf_index = req->buf_list->bgid; |
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req->flags &= ~REQ_F_BUFFER_RING; |
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} |
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} |
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} |
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static inline bool io_do_buffer_select(struct io_kiocb *req) |
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{ |
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if (!(req->flags & REQ_F_BUFFER_SELECT)) |
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return false; |
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return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)); |
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} |
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static inline void io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags) |
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{ |
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if (req->flags & REQ_F_BUFFER_SELECTED) |
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io_kbuf_recycle_legacy(req, issue_flags); |
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if (req->flags & REQ_F_BUFFER_RING) |
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io_kbuf_recycle_ring(req); |
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} |
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static inline unsigned int __io_put_kbuf_list(struct io_kiocb *req, |
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struct list_head *list) |
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{ |
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unsigned int ret = IORING_CQE_F_BUFFER | (req->buf_index << IORING_CQE_BUFFER_SHIFT); |
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if (req->flags & REQ_F_BUFFER_RING) { |
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if (req->buf_list) { |
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req->buf_index = req->buf_list->bgid; |
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req->buf_list->head++; |
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} |
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req->flags &= ~REQ_F_BUFFER_RING; |
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} else { |
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req->buf_index = req->kbuf->bgid; |
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list_add(&req->kbuf->list, list); |
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req->flags &= ~REQ_F_BUFFER_SELECTED; |
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} |
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return ret; |
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} |
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static inline unsigned int io_put_kbuf_comp(struct io_kiocb *req) |
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{ |
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lockdep_assert_held(&req->ctx->completion_lock); |
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if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING))) |
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return 0; |
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return __io_put_kbuf_list(req, &req->ctx->io_buffers_comp); |
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} |
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static inline unsigned int io_put_kbuf(struct io_kiocb *req, |
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unsigned issue_flags) |
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{ |
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if (!(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING))) |
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return 0; |
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return __io_put_kbuf(req, issue_flags); |
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} |
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#endif
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