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// SPDX-License-Identifier: GPL-2.0
#ifndef IOU_KBUF_H
#define IOU_KBUF_H
#include <uapi/linux/io_uring.h>
#include <linux/io_uring_types.h>
enum {
/* ring mapped provided buffers */
IOBL_BUF_RING = 1,
/* buffers are consumed incrementally rather than always fully */
IOBL_INC = 2,
};
struct io_buffer_list {
/*
* If ->buf_nr_pages is set, then buf_pages/buf_ring are used. If not,
* then these are classic provided buffers and ->buf_list is used.
*/
union {
struct list_head buf_list;
struct io_uring_buf_ring *buf_ring;
};
__u16 bgid;
/* below is for ring provided buffers */
__u16 buf_nr_pages;
__u16 nr_entries;
__u16 head;
__u16 mask;
__u16 flags;
struct io_mapped_region region;
};
struct io_buffer {
struct list_head list;
__u64 addr;
__u32 len;
__u16 bid;
__u16 bgid;
};
enum {
/* can alloc a bigger vec */
KBUF_MODE_EXPAND = 1,
/* if bigger vec allocated, free old one */
KBUF_MODE_FREE = 2,
};
struct buf_sel_arg {
struct iovec *iovs;
size_t out_len;
size_t max_len;
unsigned short nr_iovs;
unsigned short mode;
};
void __user *io_buffer_select(struct io_kiocb *req, size_t *len,
unsigned int issue_flags);
int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg,
unsigned int issue_flags);
int io_buffers_peek(struct io_kiocb *req, struct buf_sel_arg *arg);
void io_destroy_buffers(struct io_ring_ctx *ctx);
int io_remove_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags);
int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags);
int io_register_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
int io_unregister_pbuf_ring(struct io_ring_ctx *ctx, void __user *arg);
int io_register_pbuf_status(struct io_ring_ctx *ctx, void __user *arg);
bool io_kbuf_recycle_legacy(struct io_kiocb *req, unsigned issue_flags);
void io_kbuf_drop_legacy(struct io_kiocb *req);
unsigned int __io_put_kbufs(struct io_kiocb *req, int len, int nbufs);
bool io_kbuf_commit(struct io_kiocb *req,
struct io_buffer_list *bl, int len, int nr);
struct io_mapped_region *io_pbuf_get_region(struct io_ring_ctx *ctx,
unsigned int bgid);
static inline bool io_kbuf_recycle_ring(struct io_kiocb *req)
{
/*
* We don't need to recycle for REQ_F_BUFFER_RING, we can just clear
* the flag and hence ensure that bl->head doesn't get incremented.
* If the tail has already been incremented, hang on to it.
* The exception is partial io, that case we should increment bl->head
* to monopolize the buffer.
*/
if (req->buf_list) {
req->buf_index = req->buf_list->bgid;
req->flags &= ~(REQ_F_BUFFER_RING|REQ_F_BUFFERS_COMMIT);
return true;
}
return false;
}
static inline bool io_do_buffer_select(struct io_kiocb *req)
{
if (!(req->flags & REQ_F_BUFFER_SELECT))
return false;
return !(req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING));
}
static inline bool io_kbuf_recycle(struct io_kiocb *req, unsigned issue_flags)
{
if (req->flags & REQ_F_BL_NO_RECYCLE)
return false;
if (req->flags & REQ_F_BUFFER_SELECTED)
return io_kbuf_recycle_legacy(req, issue_flags);
if (req->flags & REQ_F_BUFFER_RING)
return io_kbuf_recycle_ring(req);
return false;
}
static inline unsigned int io_put_kbuf(struct io_kiocb *req, int len,
unsigned issue_flags)
{
if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
return 0;
return __io_put_kbufs(req, len, 1);
}
static inline unsigned int io_put_kbufs(struct io_kiocb *req, int len,
int nbufs, unsigned issue_flags)
{
if (!(req->flags & (REQ_F_BUFFER_RING | REQ_F_BUFFER_SELECTED)))
return 0;
return __io_put_kbufs(req, len, nbufs);
}
#endif
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