Merge master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6
[linux-2.6] / arch / um / os-Linux / irq.c
1 /*
2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5
6 #include <stdlib.h>
7 #include <unistd.h>
8 #include <errno.h>
9 #include <signal.h>
10 #include <string.h>
11 #include <sys/poll.h>
12 #include <sys/types.h>
13 #include <sys/time.h>
14 #include "user_util.h"
15 #include "kern_util.h"
16 #include "user.h"
17 #include "process.h"
18 #include "sigio.h"
19 #include "irq_user.h"
20 #include "os.h"
21 #include "um_malloc.h"
22
23 static struct pollfd *pollfds = NULL;
24 static int pollfds_num = 0;
25 static int pollfds_size = 0;
26
27 int os_waiting_for_events(struct irq_fd *active_fds)
28 {
29         struct irq_fd *irq_fd;
30         int i, n, err;
31
32         n = poll(pollfds, pollfds_num, 0);
33         if (n < 0) {
34                 err = -errno;
35                 if (errno != EINTR)
36                         printk("sigio_handler: os_waiting_for_events:"
37                                " poll returned %d, errno = %d\n", n, errno);
38                 return err;
39         }
40
41         if (n == 0)
42                 return 0;
43
44         irq_fd = active_fds;
45
46         for (i = 0; i < pollfds_num; i++) {
47                 if (pollfds[i].revents != 0) {
48                         irq_fd->current_events = pollfds[i].revents;
49                         pollfds[i].fd = -1;
50                 }
51                 irq_fd = irq_fd->next;
52         }
53         return n;
54 }
55
56 int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
57 {
58         if (pollfds_num == pollfds_size) {
59                 if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
60                         /* return min size needed for new pollfds area */
61                         return((pollfds_size + 1) * sizeof(pollfds[0]));
62                 }
63
64                 if (pollfds != NULL) {
65                         memcpy(tmp_pfd, pollfds,
66                                sizeof(pollfds[0]) * pollfds_size);
67                         /* remove old pollfds */
68                         kfree(pollfds);
69                 }
70                 pollfds = tmp_pfd;
71                 pollfds_size++;
72         } else
73                 kfree(tmp_pfd); /* remove not used tmp_pfd */
74
75         pollfds[pollfds_num] = ((struct pollfd) { .fd           = fd,
76                                                   .events       = events,
77                                                   .revents      = 0 });
78         pollfds_num++;
79
80         return 0;
81 }
82
83 void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
84                 struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
85 {
86         struct irq_fd **prev;
87         int i = 0;
88
89         prev = &active_fds;
90         while (*prev != NULL) {
91                 if ((*test)(*prev, arg)) {
92                         struct irq_fd *old_fd = *prev;
93                         if ((pollfds[i].fd != -1) &&
94                             (pollfds[i].fd != (*prev)->fd)) {
95                                 printk("os_free_irq_by_cb - mismatch between "
96                                        "active_fds and pollfds, fd %d vs %d\n",
97                                        (*prev)->fd, pollfds[i].fd);
98                                 goto out;
99                         }
100
101                         pollfds_num--;
102
103                         /* This moves the *whole* array after pollfds[i]
104                          * (though it doesn't spot as such)!
105                          */
106                         memmove(&pollfds[i], &pollfds[i + 1],
107                                (pollfds_num - i) * sizeof(pollfds[0]));
108                         if(*last_irq_ptr2 == &old_fd->next)
109                                 *last_irq_ptr2 = prev;
110
111                         *prev = (*prev)->next;
112                         if(old_fd->type == IRQ_WRITE)
113                                 ignore_sigio_fd(old_fd->fd);
114                         kfree(old_fd);
115                         continue;
116                 }
117                 prev = &(*prev)->next;
118                 i++;
119         }
120  out:
121         return;
122 }
123
124 int os_get_pollfd(int i)
125 {
126         return pollfds[i].fd;
127 }
128
129 void os_set_pollfd(int i, int fd)
130 {
131         pollfds[i].fd = fd;
132 }
133
134 void os_set_ioignore(void)
135 {
136         signal(SIGIO, SIG_IGN);
137 }
138
139 void init_irq_signals(int on_sigstack)
140 {
141         int flags;
142
143         flags = on_sigstack ? SA_ONSTACK : 0;
144
145         set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
146                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
147         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
148                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
149         set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
150                     SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
151         signal(SIGWINCH, SIG_IGN);
152 }