[LTP] [PATCH] Added refrence for Linux Asynchronous I/O io_uring System calls

[Vikas Kumar]

---
 configure.ac            |   3 +
 include/lapi/io_uring.h | 218 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 221 insertions(+)
 create mode 100644 include/lapi/io_uring.h

diff --git a/configure.ac b/configure.ac
index c9ec39fce..a50f793e9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -88,6 +88,9 @@ AC_CHECK_FUNCS([ \
     getdents \
     getdents64 \
     io_pgetevents \
+    io_uring_setup \
+    io_uring_register \
+    io_uring_enter \
     kcmp \
     mkdirat \
     mknodat \
diff --git a/include/lapi/io_uring.h b/include/lapi/io_uring.h
new file mode 100644
index 000000000..fc2821dd9
--- /dev/null
+++ b/include/lapi/io_uring.h
@@ -0,0 +1,218 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020 ARM. All rights reserved.
+ * Author: Vikas Kumar <vikas.kumar2@arm.com>
+ */
+
+#ifndef IO_URING_H__
+#define IO_URING_H__
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+
+
+#include "config.h"
+#include "lapi/syscalls.h"
+
+
+#ifdef __alpha__
+/*
+ * alpha is the only exception, all other architectures
+ * have common numbers for new system calls.
+ */
+# ifndef __NR_io_uring_setup
+#  define __NR_io_uring_setup		535
+# endif
+# ifndef __NR_io_uring_enter
+#  define __NR_io_uring_enter		536
+# endif
+# ifndef __NR_io_uring_register
+#  define __NR_io_uring_register	537
+# endif
+#else /* !__alpha__ */
+# ifndef __NR_io_uring_setup
+#  define __NR_io_uring_setup		425
+# endif
+# ifndef __NR_io_uring_enter
+#  define __NR_io_uring_enter		426
+# endif
+# ifndef __NR_io_uring_register
+#  define __NR_io_uring_register	427
+# endif
+#endif
+
+
+
+/*
+ * sqe->flags
+ */
+#define IOSQE_FIXED_FILE	(1U << 0)	/* use fixed fileset */
+#define IOSQE_IO_DRAIN		(1U << 1)	/* issue after inflight IO */
+#define IOSQE_IO_LINK		(1U << 2)	/* links next sqe */
+#define IOSQE_IO_HARDLINK	(1U << 3)	/* like LINK, but stronger */
+
+/*
+ * 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_SETUP_CQSIZE	(1U << 3)	/* app defines CQ size */
+
+enum {
+	IORING_OP_NOP,
+	IORING_OP_READV,
+	IORING_OP_WRITEV,
+	IORING_OP_FSYNC,
+	IORING_OP_READ_FIXED,
+	IORING_OP_WRITE_FIXED,
+	IORING_OP_POLL_ADD,
+	IORING_OP_POLL_REMOVE,
+	IORING_OP_SYNC_FILE_RANGE,
+	IORING_OP_SENDMSG,
+	IORING_OP_RECVMSG,
+	IORING_OP_TIMEOUT,
+	IORING_OP_TIMEOUT_REMOVE,
+	IORING_OP_ACCEPT,
+	IORING_OP_ASYNC_CANCEL,
+	IORING_OP_LINK_TIMEOUT,
+	IORING_OP_CONNECT,
+
+	/* this goes last, obviously */
+	IORING_OP_LAST,
+};
+
+/*
+ * sqe->fsync_flags
+ */
+#define IORING_FSYNC_DATASYNC	(1U << 0)
+
+/*
+ * sqe->timeout_flags
+ */
+#define IORING_TIMEOUT_ABS	(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 features;
+	__u32 resv[4];
+	struct io_sqring_offsets sq_off;
+	struct io_cqring_offsets cq_off;
+};
+
+/*
+ * io_uring_params->features flags
+ */
+#define IORING_FEAT_SINGLE_MMAP		(1U << 0)
+#define IORING_FEAT_NODROP		(1U << 1)
+#define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
+
+/*
+ * 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
+#define IORING_REGISTER_EVENTFD		4
+#define IORING_UNREGISTER_EVENTFD	5
+#define IORING_REGISTER_FILES_UPDATE	6
+
+struct io_uring_files_update {
+	__u32 offset;
+	__u32 resv;
+	__aligned_u64 /* __s32 * */ fds;
+};
+
+
+
+#ifndef HAVE_IO_URING_REGISTER
+int io_uring_register(int fd, unsigned int opcode, void *arg,
+		      unsigned int nr_args)
+{
+	return tst_syscall(__NR_io_uring_register, fd, opcode, arg, nr_args);
+}
+#endif /* HAVE_IO_URING_REGISTER */
+
+
+#ifndef HAVE_IO_URING_SETUP
+int io_uring_setup(unsigned int entries, struct io_uring_params *p)
+{
+	return tst_syscall(__NR_io_uring_setup, entries, p);
+}
+#endif /* HAVE_IO_URING_SETUP */
+
+#ifndef HAVE_IO_URING_ENTER
+int io_uring_enter(int fd, unsigned int to_submit, unsigned int min_complete,
+		   unsigned int flags, sigset_t *sig)
+{
+	return tst_syscall(__NR_io_uring_enter, fd, to_submit, min_complete,
+			flags, sig, _NSIG / 8);
+}
+#endif /* HAVE_IO_URING_ENTER */
+
+
+
+#endif /* IO_URING_H__ */
-- 
2.17.1