1 files changed, 81 insertions, 0 deletions
diff --git a/lib/libc/sys/io_uring_setup.c b/lib/libc/sys/io_uring_setup.c
new file mode 100644
index 00000000..0a368a81
--- /dev/null
+++ b/lib/libc/sys/io_uring_setup.c
@@ -0,0 +1,81 @@
+#include <sys/eventfd.h>
+#include <io_uring.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <syscall.h>
+
+struct io_uring __io_uring;
+
+int io_uring_setup(unsigned int entries, struct io_uring_params *params)
+{
+	return syscall(io_uring_setup, entries, params);
+}
+
+int __io_uring_setup(void)
+{
+	struct io_uring_params p;
+	memset(&p, 0, sizeof(p));
+
+	__io_uring.fd = io_uring_setup(IO_URING_ENTRIES, &p);
+
+	if (__io_uring.fd < 0)
+		return -1;
+
+	__io_uring.sq.ring_size =
+		p.sq_off.array + p.sq_entries * sizeof(unsigned int);
+	__io_uring.sq.ring = mmap(NULL, __io_uring.sq.ring_size,
+				  PROT_READ | PROT_WRITE,
+				  MAP_SHARED | MAP_POPULATE, __io_uring.fd,
+				  IORING_OFF_SQ_RING);
+
+	if (__io_uring.sq.ring == MAP_FAILED)
+		return -1;
+
+	__io_uring.sq.head = __io_uring.sq.ring + p.sq_off.head;
+	__io_uring.sq.tail = __io_uring.sq.ring + p.sq_off.tail;
+	__io_uring.sq.ring_mask = __io_uring.sq.ring + p.sq_off.ring_mask;
+	__io_uring.sq.ring_entries = __io_uring.sq.ring + p.sq_off.ring_entries;
+	__io_uring.sq.flags = __io_uring.sq.ring + p.sq_off.flags;
+	__io_uring.sq.dropped = __io_uring.sq.ring + p.sq_off.dropped;
+	__io_uring.sq.array = __io_uring.sq.ring + p.sq_off.array;
+	__io_uring.sq.sqes =
+		mmap(NULL, p.sq_entries * sizeof(struct io_uring_sqe),
+		     PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE,
+		     __io_uring.fd, IORING_OFF_SQES);
+
+	if (__io_uring.sq.sqes == MAP_FAILED) {
+		munmap(__io_uring.sq.ring, __io_uring.sq.ring_size);
+		return -1;
+	}
+
+	__io_uring.cq.ring_size =
+		p.cq_off.cqes + p.cq_entries * sizeof(struct io_uring_cqe);
+	__io_uring.cq.ring = mmap(NULL, __io_uring.cq.ring_size,
+				  PROT_READ | PROT_WRITE,
+				  MAP_SHARED | MAP_POPULATE, __io_uring.fd,
+				  IORING_OFF_CQ_RING);
+
+	if (__io_uring.cq.ring == MAP_FAILED) {
+		munmap(__io_uring.sq.ring, __io_uring.sq.ring_size);
+		munmap(__io_uring.sq.sqes,
+		       p.sq_entries * sizeof(struct io_uring_sqe));
+		return -1;
+	}
+
+	__io_uring.eventfd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+	if (__io_uring.eventfd < 0)
+		return -1;
+
+	io_uring_register(__io_uring.fd, IORING_REGISTER_EVENTFD,
+			  &__io_uring.eventfd, 1);
+
+	__io_uring.cq.head = __io_uring.cq.ring + p.cq_off.head;
+	__io_uring.cq.tail = __io_uring.cq.ring + p.cq_off.tail;
+	__io_uring.cq.ring_mask = __io_uring.cq.ring + p.cq_off.ring_mask;
+	__io_uring.cq.ring_entries = __io_uring.cq.ring + p.cq_off.ring_entries;
+	__io_uring.cq.overflow = __io_uring.cq.ring + p.cq_off.overflow;
+	__io_uring.cq.cqes = __io_uring.cq.ring + p.cq_off.cqes;
+	__io_uring.cq.flags = __io_uring.cq.ring + p.cq_off.flags;
+
+	return 0;
+}