1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include <linux/slab.h>
7*4882a593Smuzhiyun #include <linux/completion.h>
8*4882a593Smuzhiyun #include <linux/irqreturn.h>
9*4882a593Smuzhiyun #include <asm/irq.h>
10*4882a593Smuzhiyun #include <irq_kern.h>
11*4882a593Smuzhiyun #include <os.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun struct xterm_wait {
14*4882a593Smuzhiyun struct completion ready;
15*4882a593Smuzhiyun int fd;
16*4882a593Smuzhiyun int pid;
17*4882a593Smuzhiyun int new_fd;
18*4882a593Smuzhiyun };
19*4882a593Smuzhiyun
xterm_interrupt(int irq,void * data)20*4882a593Smuzhiyun static irqreturn_t xterm_interrupt(int irq, void *data)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun struct xterm_wait *xterm = data;
23*4882a593Smuzhiyun int fd;
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun fd = os_rcv_fd(xterm->fd, &xterm->pid);
26*4882a593Smuzhiyun if (fd == -EAGAIN)
27*4882a593Smuzhiyun return IRQ_NONE;
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun xterm->new_fd = fd;
30*4882a593Smuzhiyun complete(&xterm->ready);
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun return IRQ_HANDLED;
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun
xterm_fd(int socket,int * pid_out)35*4882a593Smuzhiyun int xterm_fd(int socket, int *pid_out)
36*4882a593Smuzhiyun {
37*4882a593Smuzhiyun struct xterm_wait *data;
38*4882a593Smuzhiyun int err, ret;
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun data = kmalloc(sizeof(*data), GFP_KERNEL);
41*4882a593Smuzhiyun if (data == NULL) {
42*4882a593Smuzhiyun printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n");
43*4882a593Smuzhiyun return -ENOMEM;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun /* This is a locked semaphore... */
47*4882a593Smuzhiyun *data = ((struct xterm_wait) { .fd = socket,
48*4882a593Smuzhiyun .pid = -1,
49*4882a593Smuzhiyun .new_fd = -1 });
50*4882a593Smuzhiyun init_completion(&data->ready);
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt,
53*4882a593Smuzhiyun IRQF_SHARED, "xterm", data);
54*4882a593Smuzhiyun if (err) {
55*4882a593Smuzhiyun printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "
56*4882a593Smuzhiyun "err = %d\n", err);
57*4882a593Smuzhiyun ret = err;
58*4882a593Smuzhiyun goto out;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun /* ... so here we wait for an xterm interrupt.
62*4882a593Smuzhiyun *
63*4882a593Smuzhiyun * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY
64*4882a593Smuzhiyun * isn't set) this will hang... */
65*4882a593Smuzhiyun wait_for_completion(&data->ready);
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun um_free_irq(XTERM_IRQ, data);
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun ret = data->new_fd;
70*4882a593Smuzhiyun *pid_out = data->pid;
71*4882a593Smuzhiyun out:
72*4882a593Smuzhiyun kfree(data);
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun return ret;
75*4882a593Smuzhiyun }
76