[LTP] [PATCH 1/3] syscall: Add io_uring test

[Vikas Kumar <vikas.kumar2@arm.com>]

Added Linux asynchronous I/O API Test for
io_uring_setup(), io_uring_register() and io_uring_enter().
This test will check io_uring api basic operation.

Signed-off-by: Vikas Kumar <vikas.kumar2@arm.com>
---
 testcases/kernel/syscalls/io_uring/Makefile   |   8 +
 .../kernel/syscalls/io_uring/io_uring01.c     | 194 ++++++++++++++++++
 2 files changed, 202 insertions(+)
 create mode 100644 testcases/kernel/syscalls/io_uring/Makefile
 create mode 100644 testcases/kernel/syscalls/io_uring/io_uring01.c

diff --git a/testcases/kernel/syscalls/io_uring/Makefile b/testcases/kernel/syscalls/io_uring/Makefile
new file mode 100644
index 000000000..24cd01ba8
--- /dev/null
+++ b/testcases/kernel/syscalls/io_uring/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2020 ARM Embedded Technologies Private Ltd. All rights reserved.
+
+top_srcdir		?= ../../../..
+
+include $(top_srcdir)/include/mk/testcases.mk
+
+include $(top_srcdir)/include/mk/generic_leaf_target.mk
diff --git a/testcases/kernel/syscalls/io_uring/io_uring01.c b/testcases/kernel/syscalls/io_uring/io_uring01.c
new file mode 100644
index 000000000..cfa1e5c9a
--- /dev/null
+++ b/testcases/kernel/syscalls/io_uring/io_uring01.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 ARM Embedded Technologies Private Ltd. All rights reserved.
+ * Author: Vikas Kumar <vikas.kumar2@arm.com>
+ *
+ * Added Test for Linux asynchronous I/O raw API: io_uring_setup(), io_uring_register() and io_uring_enter().
+ */
+
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#include "config.h"
+#include "tst_test.h"
+#include "lapi/io_uring.h"
+
+char *TCID = "io_uring01";
+
+static struct tcase {
+	int test_count;
+	int flag;
+}tcases[] = {{1, 0},};
+
+#define QUEUE_DEPTH 1
+#define BLOCK_SZ    1024
+
+struct io_sq_ring {
+	unsigned *head;
+	unsigned *tail;
+	unsigned *ring_mask;
+	unsigned *ring_entries;
+	unsigned *flags;
+	unsigned *array;
+};
+
+struct io_cq_ring {
+	unsigned *head;
+	unsigned *tail;
+	unsigned *ring_mask;
+	unsigned *ring_entries;
+	struct io_uring_cqe *cqes;
+};
+
+struct submitter {
+    int ring_fd;
+    struct io_sq_ring sq_ring;
+    struct io_uring_sqe *sqes;
+    struct io_cq_ring cq_ring;
+};
+
+struct file_info {
+    off_t buff_sz;
+    struct iovec iovecs[];      
+};
+
+struct submitter *s;
+struct file_info *fi;
+sigset_t sig;
+
+int setup_io_uring_test(struct submitter *s) {
+    struct io_sq_ring *sring = &s->sq_ring;
+    struct io_cq_ring *cring = &s->cq_ring;
+    struct io_uring_params p;
+    void *ptr;
+
+    memset(&p, 0, sizeof(p));
+    s->ring_fd = io_uring_setup(QUEUE_DEPTH, &p);
+    if (-1 == s->ring_fd) {
+	tst_res(TFAIL | TTERRNO, "io_uring setup return error");
+        return 1;
+    }
+    //submission queue ring buffer mapping
+    ptr = mmap(0, p.sq_off.array + p.sq_entries * sizeof(__u32),
+            PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+            s->ring_fd, IORING_OFF_SQ_RING);
+    if (ptr == MAP_FAILED) {        
+        return 1;
+    }
+
+    // save global submission queue struct info
+    sring->head = ptr + p.sq_off.head;
+    sring->tail = ptr + p.sq_off.tail;
+    sring->ring_mask = ptr + p.sq_off.ring_mask;
+    sring->ring_entries = ptr + p.sq_off.ring_entries;
+    sring->flags = ptr + p.sq_off.flags;
+    sring->array = ptr + p.sq_off.array;
+
+    //submission queue entries ring buffer mapping
+    s->sqes = mmap(0, p.sq_entries * sizeof(struct io_uring_sqe),
+            PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+            s->ring_fd, IORING_OFF_SQES);
+    if (s->sqes == MAP_FAILED) {        
+        return 1;
+    }
+
+    //completion queue ring buffer mapping
+    ptr = mmap(0,
+            p.cq_off.cqes + p.cq_entries * sizeof(struct io_uring_cqe),
+            PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+            s->ring_fd, IORING_OFF_CQ_RING);
+    if (ptr == MAP_FAILED) {
+        return 1;
+    }
+
+    //save global completion queue struct info
+    cring->head = ptr + p.cq_off.head;
+    cring->tail = ptr + p.cq_off.tail;
+    cring->ring_mask = ptr + p.cq_off.ring_mask;
+    cring->ring_entries = ptr + p.cq_off.ring_entries;
+    cring->cqes = ptr + p.cq_off.cqes;
+    
+    return 0;
+}
+
+int submit_to_uring_sq(struct submitter *s) {
+
+    unsigned index = 0, tail = 0, next_tail = 0;
+    struct io_sq_ring *sring = &s->sq_ring;
+    int ret;    
+
+    fi = malloc(sizeof(*fi));
+    if (!fi) {
+        return 1;
+    }
+
+    fi->buff_sz = BLOCK_SZ;
+    fi->iovecs[index].iov_base = (void *)fi; 
+    fi->iovecs[index].iov_len = (size_t)fi->buff_sz; 
+ 
+    ret = io_uring_register(s->ring_fd, IORING_REGISTER_BUFFERS, fi->iovecs, QUEUE_DEPTH);
+    if (0 != ret) {
+	tst_res(TFAIL | TTERRNO, "io_uring register return error: %d", ret);
+        return 1;
+    }    
+
+    //Submission queue entry addition to the tail of the SQE ring buffer
+    next_tail = tail = *sring->tail;
+    next_tail++;
+    index = tail & *s->sq_ring.ring_mask;
+    struct io_uring_sqe *sqe = &s->sqes[index];
+    sqe->flags = 0;
+    sqe->opcode = IORING_OP_NOP; 
+    sqe->addr = (unsigned long) fi->iovecs;
+    sqe->user_data = (unsigned long long) fi;
+    sring->array[index] = index;
+    tail = next_tail;
+
+    //Kernel to notice the tail update 
+    if(*sring->tail != tail) {
+        *sring->tail = tail;
+    }
+
+    ret =  io_uring_enter(s->ring_fd, 1, 1, IORING_ENTER_GETEVENTS, &sig);
+    if(ret < 0) {
+	tst_res(TFAIL | TTERRNO, "io_uring enter return error");
+        return 1;
+    }
+
+    return 0;
+}
+
+static void setup(void){
+	int ret;
+	s = malloc(sizeof(*s));
+    	if (!s) {
+        	return;
+    	}
+	memset(s, 0, sizeof(*s));
+	ret = setup_io_uring_test(s);
+	if (ret) {
+		tst_res(TFAIL | TTERRNO, "io_uring setup status: %d", ret);
+    	}	
+}
+
+static void run(void){
+	int ret;
+	ret = submit_to_uring_sq(s);
+	if (ret) {
+		tst_res(TFAIL | TTERRNO, "io_uring submit status: %d", ret);
+    	}else{
+		tst_res(TPASS, "functionality of io_uring() is correct");
+	}
+}
+
+static void cleanup(void){
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.test = run,
+	.cleanup = cleanup,	
+	.tcnt = ARRAY_SIZE(tcases),
+};
+
-- 
2.17.1