LXR linux/arch/um/drivers/ubd

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2016 Anton Ivanov (aivanov@brocade.com)
   4 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   5 * Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
   6 */
   7
   8#include <stddef.h>
   9#include <unistd.h>
  10#include <errno.h>
  11#include <sched.h>
  12#include <signal.h>
  13#include <string.h>
  14#include <netinet/in.h>
  15#include <sys/time.h>
  16#include <sys/socket.h>
  17#include <sys/mman.h>
  18#include <sys/param.h>
  19#include <endian.h>
  20#include <byteswap.h>
  21
  22#include "ubd.h"
  23#include <os.h>
  24#include <poll.h>
  25
  26struct pollfd kernel_pollfd;
  27
  28int start_io_thread(unsigned long sp, int *fd_out)
  29{
  30        int pid, fds[2], err;
  31
  32        err = os_pipe(fds, 1, 1);
  33        if(err < 0){
  34                printk("start_io_thread - os_pipe failed, err = %d\n", -err);
  35                goto out;
  36        }
  37
  38        kernel_fd = fds[0];
  39        kernel_pollfd.fd = kernel_fd;
  40        kernel_pollfd.events = POLLIN;
  41        *fd_out = fds[1];
  42
  43        err = os_set_fd_block(*fd_out, 0);
  44        err = os_set_fd_block(kernel_fd, 0);
  45        if (err) {
  46                printk("start_io_thread - failed to set nonblocking I/O.\n");
  47                goto out_close;
  48        }
  49
  50        pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM, NULL);
  51        if(pid < 0){
  52                err = -errno;
  53                printk("start_io_thread - clone failed : errno = %d\n", errno);
  54                goto out_close;
  55        }
  56
  57        return(pid);
  58
  59 out_close:
  60        os_close_file(fds[0]);
  61        os_close_file(fds[1]);
  62        kernel_fd = -1;
  63        *fd_out = -1;
  64 out:
  65        return err;
  66}
  67
  68int ubd_read_poll(int timeout)
  69{
  70        kernel_pollfd.events = POLLIN;
  71        return poll(&kernel_pollfd, 1, timeout);
  72}
  73int ubd_write_poll(int timeout)
  74{
  75        kernel_pollfd.events = POLLOUT;
  76        return poll(&kernel_pollfd, 1, timeout);
  77}
  78
  79