Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / 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/irq.h"
11 #include "irq_user.h"
12 #include "irq_kern.h"
13 #include "kern_util.h"
14 #include "os.h"
15 #include "xterm.h"
16
17 struct xterm_wait {
18         struct completion ready;
19         int fd;
20         int pid;
21         int new_fd;
22 };
23
24 static irqreturn_t xterm_interrupt(int irq, void *data, struct pt_regs *regs)
25 {
26         struct xterm_wait *xterm = data;
27         int fd;
28
29         fd = os_rcv_fd(xterm->fd, &xterm->pid);
30         if(fd == -EAGAIN)
31                 return(IRQ_NONE);
32
33         xterm->new_fd = fd;
34         complete(&xterm->ready);
35         return(IRQ_HANDLED);
36 }
37
38 int xterm_fd(int socket, int *pid_out)
39 {
40         struct xterm_wait *data;
41         int err, ret;
42
43         data = kmalloc(sizeof(*data), GFP_KERNEL);
44         if(data == NULL){
45                 printk(KERN_ERR "xterm_fd : failed to allocate xterm_wait\n");
46                 return(-ENOMEM);
47         }
48
49         /* This is a locked semaphore... */
50         *data = ((struct xterm_wait) 
51                 { .fd           = socket,
52                   .pid          = -1,
53                   .new_fd       = -1 });
54         init_completion(&data->ready);
55
56         err = um_request_irq(XTERM_IRQ, socket, IRQ_READ, xterm_interrupt, 
57                              SA_INTERRUPT | SA_SHIRQ | SA_SAMPLE_RANDOM, 
58                              "xterm", data);
59         if (err){
60                 printk(KERN_ERR "xterm_fd : failed to get IRQ for xterm, "
61                        "err = %d\n",  err);
62                 ret = err;
63                 goto out;
64         }
65
66         /* ... so here we wait for an xterm interrupt.
67          *
68          * XXX Note, if the xterm doesn't work for some reason (eg. DISPLAY
69          * isn't set) this will hang... */
70         wait_for_completion(&data->ready);
71
72         free_irq(XTERM_IRQ, data);
73
74         ret = data->new_fd;
75         *pid_out = data->pid;
76  out:
77         kfree(data);
78
79         return(ret);
80 }
81
82 /*
83  * Overrides for Emacs so that we follow Linus's tabbing style.
84  * Emacs will notice this stuff at the end of the file and automatically
85  * adjust the settings for this buffer only.  This must remain at the end
86  * of the file.
87  * ---------------------------------------------------------------------------
88  * Local variables:
89  * c-file-style: "linux"
90  * End:
91  */