1 files changed, 78 insertions, 0 deletions
diff --git a/arch/um/drivers/ubd_user.c b/arch/um/drivers/ubd_user.c
new file mode 100644
index 0000000000..a1afe414ce
--- /dev/null
+++ b/arch/um/drivers/ubd_user.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016 Anton Ivanov (aivanov@brocade.com)
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
+ */
+
+#include <stddef.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include <endian.h>
+#include <byteswap.h>
+
+#include "ubd.h"
+#include <os.h>
+#include <poll.h>
+
+struct pollfd kernel_pollfd;
+
+int start_io_thread(unsigned long sp, int *fd_out)
+{
+	int pid, fds[2], err;
+
+	err = os_pipe(fds, 1, 1);
+	if(err < 0){
+		printk("start_io_thread - os_pipe failed, err = %d\n", -err);
+		goto out;
+	}
+
+	kernel_fd = fds[0];
+	kernel_pollfd.fd = kernel_fd;
+	kernel_pollfd.events = POLLIN;
+	*fd_out = fds[1];
+
+	err = os_set_fd_block(*fd_out, 0);
+	err = os_set_fd_block(kernel_fd, 0);
+	if (err) {
+		printk("start_io_thread - failed to set nonblocking I/O.\n");
+		goto out_close;
+	}
+
+	pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM, NULL);
+	if(pid < 0){
+		err = -errno;
+		printk("start_io_thread - clone failed : errno = %d\n", errno);
+		goto out_close;
+	}
+
+	return(pid);
+
+ out_close:
+	os_close_file(fds[0]);
+	os_close_file(fds[1]);
+	kernel_fd = -1;
+	*fd_out = -1;
+ out:
+	return err;
+}
+
+int ubd_read_poll(int timeout)
+{
+	kernel_pollfd.events = POLLIN;
+	return poll(&kernel_pollfd, 1, timeout);
+}
+int ubd_write_poll(int timeout)
+{
+	kernel_pollfd.events = POLLOUT;
+	return poll(&kernel_pollfd, 1, timeout);
+}
+