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Diffstat (limited to 'src/io_uring.h')
-rw-r--r-- | src/io_uring.h | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/src/io_uring.h b/src/io_uring.h new file mode 100644 index 0000000..7dd2112 --- /dev/null +++ b/src/io_uring.h @@ -0,0 +1,115 @@ +/* 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 + */ +struct io_uring_iocb { + __u8 opcode; + __u8 flags; + __u16 ioprio; + __s32 fd; + __u64 off; + union { + void *addr; + __u64 __pad; + }; + __u32 len; + union { + __kernel_rwf_t rw_flags; + __u32 __resv; + }; +}; + +/* + * io_uring_setup() flags + */ +#define IORING_SETUP_IOPOLL (1 << 0) /* io_context is polled */ +#define IORING_SETUP_FIXEDBUFS (1 << 1) /* IO buffers are fixed */ +#define IORING_SETUP_SQTHREAD (1 << 2) /* Use SQ thread */ +#define IORING_SETUP_SQWQ (1 << 3) /* Use SQ workqueue */ +#define IORING_SETUP_SQPOLL (1 << 4) /* SQ thread polls */ + +#define IORING_OP_READ 1 +#define IORING_OP_WRITE 2 +#define IORING_OP_FSYNC 3 +#define IORING_OP_FDSYNC 4 +#define IORING_OP_READ_FIXED 5 +#define IORING_OP_WRITE_FIXED 6 + +/* + * IO completion data structure + */ +struct io_uring_event { + __u64 index; /* what iocb this event came from */ + __s32 res; /* result code for this event */ + __u32 flags; +}; + +/* + * io_uring_event->flags + */ +#define IOEV_FLAG_CACHEHIT (1 << 0) /* IO did not hit media */ + +/* + * 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_IOCB 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 resv[3]; +}; + +#define IORING_SQ_NEED_WAKEUP (1 << 0) /* needs io_uring_enter wakeup */ + +struct io_cqring_offsets { + __u32 head; + __u32 tail; + __u32 ring_mask; + __u32 ring_entries; + __u32 overflow; + __u32 events; + __u32 resv[4]; +}; + +/* + * io_uring_enter(2) flags + */ +#define IORING_ENTER_GETEVENTS (1 << 0) + +/* + * 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; + __u16 sq_thread_cpu; + __u16 resv[9]; + struct io_sqring_offsets sq_off; + struct io_cqring_offsets cq_off; +}; + +#endif |