/arch/um/drivers/xterm_kern.c

 1/* 
 2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
 3 * Licensed under the GPL
 4 */
 5
 6#include "linux/errno.h"
 7#include "linux/slab.h"
 8#include "linux/signal.h"
 9#include "linux/interrupt.h"
10#include "asm/semaphore.h"
11#include "asm/irq.h"
12#include "irq_user.h"
13#include "irq_kern.h"
14#include "kern_util.h"
15#include "os.h"
16#include "xterm.h"
17
18struct xterm_wait {
19	struct completion ready;
20	int fd;
21	int pid;
22	int new_fd;
23};
24
25static irqreturn_t xterm_interrupt(int irq, void *data, struct pt_regs *regs)
26{
27	struct xterm_wait *xterm = data;
28	int fd;
29
30	fd = os_rcv_fd(xterm->fd, &xterm->pid);
31	if(fd == -EAGAIN)
32		return(IRQ_NONE);
33
34	xterm->new_fd = fd;
35	complete(&xterm->ready);
36	return(IRQ_HANDLED);
37}
38
39int xterm_fd(int socket, int *pid_out)
40{
41	struct xterm_wait *data;
42	int err, ret;
43
44	data = kmalloc(sizeof(*data), GFP_KERNEL);
45	if(data == NULL){
46		printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n");
47		return(-ENOMEM);
48	}
49
50	/* This is a locked semaphore... */
51	*data = ((struct xterm_wait) 
52		{ .fd 		= socket,
53		  .pid 		= -1,
54		  .new_fd 	= -1 });
55	init_completion(&data->ready);
56
57	err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt, 
58			     SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, 
59			     "xterm", data);
60	if (err){
61		printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "
62		       "err = %d\n",  err);
63		ret = err;
64		goto out;
65	}
66
67	/* ... so here we wait for an xterm interrupt.
68	 *
69	 * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY
70	 * isn't set) this will hang... */
71	wait_for_completion(&data->ready);
72
73	free_irq_by_irq_and_dev(XTERM_IRQ, data);
74	free_irq(XTERM_IRQ, data);
75
76	ret = data->new_fd;
77	*pid_out = data->pid;
78 out:
79	kfree(data);
80
81	return(ret);
82}
83
84/*
85 * Overrides for Emacs so that we follow Linus's tabbing style.
86 * Emacs will notice this stuff at the end of the file and automatically
87 * adjust the settings for this buffer only.  This must remain at the end
88 * of the file.
89 * ---------------------------------------------------------------------------
90 * Local variables:
91 * c-file-style: "linux"
92 * End:
93 */