mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-21 02:01:05 +07:00
221c5eb233
This is basically a direct port of bfe4037e72, which implements a
one-shot poll command through aio. Description below is based on that
commit as well. However, instead of adding a POLL command and relying
on io_cancel(2) to remove it, we mimic the epoll(2) interface of
having a command to add a poll notification, IORING_OP_POLL_ADD,
and one to remove it again, IORING_OP_POLL_REMOVE.
To poll for a file descriptor the application should submit an sqe of
type IORING_OP_POLL. It will poll the fd for the events specified in the
poll_events field.
Unlike poll or epoll without EPOLLONESHOT this interface always works in
one shot mode, that is once the sqe is completed, it will have to be
resubmitted.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Based-on-code-from: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
138 lines
2.9 KiB
C
138 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
|
|
/*
|
|
* Header file for the io_uring interface.
|
|
*
|
|
* Copyright (C) 2019 Jens Axboe
|
|
* Copyright (C) 2019 Christoph Hellwig
|
|
*/
|
|
#ifndef LINUX_IO_URING_H
|
|
#define LINUX_IO_URING_H
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/types.h>
|
|
|
|
/*
|
|
* IO submission data structure (Submission Queue Entry)
|
|
*/
|
|
struct io_uring_sqe {
|
|
__u8 opcode; /* type of operation for this sqe */
|
|
__u8 flags; /* IOSQE_ flags */
|
|
__u16 ioprio; /* ioprio for the request */
|
|
__s32 fd; /* file descriptor to do IO on */
|
|
__u64 off; /* offset into file */
|
|
__u64 addr; /* pointer to buffer or iovecs */
|
|
__u32 len; /* buffer size or number of iovecs */
|
|
union {
|
|
__kernel_rwf_t rw_flags;
|
|
__u32 fsync_flags;
|
|
__u16 poll_events;
|
|
};
|
|
__u64 user_data; /* data to be passed back at completion time */
|
|
union {
|
|
__u16 buf_index; /* index into fixed buffers, if used */
|
|
__u64 __pad2[3];
|
|
};
|
|
};
|
|
|
|
/*
|
|
* sqe->flags
|
|
*/
|
|
#define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */
|
|
|
|
/*
|
|
* io_uring_setup() flags
|
|
*/
|
|
#define IORING_SETUP_IOPOLL (1U << 0) /* io_context is polled */
|
|
#define IORING_SETUP_SQPOLL (1U << 1) /* SQ poll thread */
|
|
#define IORING_SETUP_SQ_AFF (1U << 2) /* sq_thread_cpu is valid */
|
|
|
|
#define IORING_OP_NOP 0
|
|
#define IORING_OP_READV 1
|
|
#define IORING_OP_WRITEV 2
|
|
#define IORING_OP_FSYNC 3
|
|
#define IORING_OP_READ_FIXED 4
|
|
#define IORING_OP_WRITE_FIXED 5
|
|
#define IORING_OP_POLL_ADD 6
|
|
#define IORING_OP_POLL_REMOVE 7
|
|
|
|
/*
|
|
* sqe->fsync_flags
|
|
*/
|
|
#define IORING_FSYNC_DATASYNC (1U << 0)
|
|
|
|
/*
|
|
* IO completion data structure (Completion Queue Entry)
|
|
*/
|
|
struct io_uring_cqe {
|
|
__u64 user_data; /* sqe->data submission passed back */
|
|
__s32 res; /* result code for this event */
|
|
__u32 flags;
|
|
};
|
|
|
|
/*
|
|
* Magic offsets for the application to mmap the data it needs
|
|
*/
|
|
#define IORING_OFF_SQ_RING 0ULL
|
|
#define IORING_OFF_CQ_RING 0x8000000ULL
|
|
#define IORING_OFF_SQES 0x10000000ULL
|
|
|
|
/*
|
|
* Filled with the offset for mmap(2)
|
|
*/
|
|
struct io_sqring_offsets {
|
|
__u32 head;
|
|
__u32 tail;
|
|
__u32 ring_mask;
|
|
__u32 ring_entries;
|
|
__u32 flags;
|
|
__u32 dropped;
|
|
__u32 array;
|
|
__u32 resv1;
|
|
__u64 resv2;
|
|
};
|
|
|
|
/*
|
|
* sq_ring->flags
|
|
*/
|
|
#define IORING_SQ_NEED_WAKEUP (1U << 0) /* needs io_uring_enter wakeup */
|
|
|
|
struct io_cqring_offsets {
|
|
__u32 head;
|
|
__u32 tail;
|
|
__u32 ring_mask;
|
|
__u32 ring_entries;
|
|
__u32 overflow;
|
|
__u32 cqes;
|
|
__u64 resv[2];
|
|
};
|
|
|
|
/*
|
|
* io_uring_enter(2) flags
|
|
*/
|
|
#define IORING_ENTER_GETEVENTS (1U << 0)
|
|
#define IORING_ENTER_SQ_WAKEUP (1U << 1)
|
|
|
|
/*
|
|
* Passed in for io_uring_setup(2). Copied back with updated info on success
|
|
*/
|
|
struct io_uring_params {
|
|
__u32 sq_entries;
|
|
__u32 cq_entries;
|
|
__u32 flags;
|
|
__u32 sq_thread_cpu;
|
|
__u32 sq_thread_idle;
|
|
__u32 resv[5];
|
|
struct io_sqring_offsets sq_off;
|
|
struct io_cqring_offsets cq_off;
|
|
};
|
|
|
|
/*
|
|
* io_uring_register(2) opcodes and arguments
|
|
*/
|
|
#define IORING_REGISTER_BUFFERS 0
|
|
#define IORING_UNREGISTER_BUFFERS 1
|
|
#define IORING_REGISTER_FILES 2
|
|
#define IORING_UNREGISTER_FILES 3
|
|
|
|
#endif
|