selftests/io_uring: support NO_SQARRAY in miniliburing

Add support for IORING_SETUP_NO_SQARRAY in miniliburing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

tools/include/io_uring/mini_liburing.h

@@ -6,6 +6,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/uio.h>
 
 struct io_sq_ring {
 	unsigned int *head;
@@ -55,6 +56,7 @@ struct io_uring {
 	struct io_uring_sq sq;
 	struct io_uring_cq cq;
 	int ring_fd;
+	unsigned flags;
 };
 
 #if defined(__x86_64) || defined(__i386__)
@@ -72,7 +74,14 @@ static inline int io_uring_mmap(int fd, struct io_uring_params *p,
 	void *ptr;
 	int ret;
 
-	sq->ring_sz = p->sq_off.array + p->sq_entries * sizeof(unsigned int);
+	if (p->flags & IORING_SETUP_NO_SQARRAY) {
+		sq->ring_sz = p->cq_off.cqes;
+		sq->ring_sz += p->cq_entries * sizeof(struct io_uring_cqe);
+	} else {
+		sq->ring_sz = p->sq_off.array;
+		sq->ring_sz += p->sq_entries * sizeof(unsigned int);
+	}
+
 	ptr = mmap(0, sq->ring_sz, PROT_READ | PROT_WRITE,
 		   MAP_SHARED | MAP_POPULATE, fd, IORING_OFF_SQ_RING);
 	if (ptr == MAP_FAILED)
@@ -83,7 +92,8 @@ static inline int io_uring_mmap(int fd, struct io_uring_params *p,
 	sq->kring_entries = ptr + p->sq_off.ring_entries;
 	sq->kflags = ptr + p->sq_off.flags;
 	sq->kdropped = ptr + p->sq_off.dropped;
-	sq->array = ptr + p->sq_off.array;
+	if (!(p->flags & IORING_SETUP_NO_SQARRAY))
+		sq->array = ptr + p->sq_off.array;
 
 	size = p->sq_entries * sizeof(struct io_uring_sqe);
 	sq->sqes = mmap(0, size, PROT_READ | PROT_WRITE,
@@ -138,10 +148,12 @@ static inline int io_uring_queue_init_params(unsigned int entries,
 	if (fd < 0)
 		return fd;
 	ret = io_uring_mmap(fd, p, &ring->sq, &ring->cq);
-	if (!ret)
+	if (!ret) {
 		ring->ring_fd = fd;
-	else
+		ring->flags = p->flags;
+	} else {
 		close(fd);
+	}
 	return ret;
 }
 
@@ -208,10 +220,18 @@ static inline int io_uring_submit(struct io_uring *ring)
 
 	ktail = *sq->ktail;
 	to_submit = sq->sqe_tail - sq->sqe_head;
-	for (submitted = 0; submitted < to_submit; submitted++) {
-		read_barrier();
-		sq->array[ktail++ & mask] = sq->sqe_head++ & mask;
+
+	if (!(ring->flags & IORING_SETUP_NO_SQARRAY)) {
+		for (submitted = 0; submitted < to_submit; submitted++) {
+			read_barrier();
+			sq->array[ktail++ & mask] = sq->sqe_head++ & mask;
+		}
+	} else {
+		ktail += to_submit;
+		sq->sqe_head += to_submit;
+		submitted = to_submit;
 	}
+
 	if (!submitted)
 		return 0;