Initial commit

Signed-off-by: Jens Axboe <axboe@kernel.dk>

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