Pull error-inject into release branch
[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 /*
24  * Locked by irq_lock in arch/um/kernel/irq.c.  Changed by os_create_pollfd
25  * and os_free_irq_by_cb, which are called under irq_lock.
26  */
27 static struct pollfd *pollfds = NULL;
28 static int pollfds_num = 0;
29 static int pollfds_size = 0;
30
31 int os_waiting_for_events(struct irq_fd *active_fds)
32 {
33         struct irq_fd *irq_fd;
34         int i, n, err;
35
36         n = poll(pollfds, pollfds_num, 0);
37         if (n < 0) {
38                 err = -errno;
39                 if (errno != EINTR)
40                         printk("sigio_handler: os_waiting_for_events:"
41                                " poll returned %d, errno = %d\n", n, errno);
42                 return err;
43         }
44
45         if (n == 0)
46                 return 0;
47
48         irq_fd = active_fds;
49
50         for (i = 0; i < pollfds_num; i++) {
51                 if (pollfds[i].revents != 0) {
52                         irq_fd->current_events = pollfds[i].revents;
53                         pollfds[i].fd = -1;
54                 }
55                 irq_fd = irq_fd->next;
56         }
57         return n;
58 }
59
60 int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
61 {
62         if (pollfds_num == pollfds_size) {
63                 if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
64                         /* return min size needed for new pollfds area */
65                         return (pollfds_size + 1) * sizeof(pollfds[0]);
66                 }
67
68                 if (pollfds != NULL) {
69                         memcpy(tmp_pfd, pollfds,
70                                sizeof(pollfds[0]) * pollfds_size);
71                         /* remove old pollfds */
72                         kfree(pollfds);
73                 }
74                 pollfds = tmp_pfd;
75                 pollfds_size++;
76         } else
77                 kfree(tmp_pfd); /* remove not used tmp_pfd */
78
79         pollfds[pollfds_num] = ((struct pollfd) { .fd           = fd,
80                                                   .events       = events,
81                                                   .revents      = 0 });
82         pollfds_num++;
83
84         return 0;
85 }
86
87 void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
88                 struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
89 {
90         struct irq_fd **prev;
91         int i = 0;
92
93         prev = &active_fds;
94         while (*prev != NULL) {
95                 if ((*test)(*prev, arg)) {
96                         struct irq_fd *old_fd = *prev;
97                         if ((pollfds[i].fd != -1) &&
98                             (pollfds[i].fd != (*prev)->fd)) {
99                                 printk("os_free_irq_by_cb - mismatch between "
100                                        "active_fds and pollfds, fd %d vs %d\n",
101                                        (*prev)->fd, pollfds[i].fd);
102                                 goto out;
103                         }
104
105                         pollfds_num--;
106
107                         /* This moves the *whole* array after pollfds[i]
108                          * (though it doesn't spot as such)!
109                          */
110                         memmove(&pollfds[i], &pollfds[i + 1],
111                                (pollfds_num - i) * sizeof(pollfds[0]));
112                         if(*last_irq_ptr2 == &old_fd->next)
113                                 *last_irq_ptr2 = prev;
114
115                         *prev = (*prev)->next;
116                         if(old_fd->type == IRQ_WRITE)
117                                 ignore_sigio_fd(old_fd->fd);
118                         kfree(old_fd);
119                         continue;
120                 }
121                 prev = &(*prev)->next;
122                 i++;
123         }
124  out:
125         return;
126 }
127
128 int os_get_pollfd(int i)
129 {
130         return pollfds[i].fd;
131 }
132
133 void os_set_pollfd(int i, int fd)
134 {
135         pollfds[i].fd = fd;
136 }
137
138 void os_set_ioignore(void)
139 {
140         signal(SIGIO, SIG_IGN);
141 }
142
143 void init_irq_signals(int on_sigstack)
144 {
145         int flags;
146
147         flags = on_sigstack ? SA_ONSTACK : 0;
148
149         set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
150                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
151         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
152                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
153         set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
154                     SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
155         signal(SIGWINCH, SIG_IGN);
156 }