Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6] / arch / um / os-Linux / irq.c
1 /*
2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5
6 #include <stdlib.h>
7 #include <errno.h>
8 #include <poll.h>
9 #include <signal.h>
10 #include <string.h>
11 #include "irq_user.h"
12 #include "kern_constants.h"
13 #include "os.h"
14 #include "process.h"
15 #include "um_malloc.h"
16 #include "user.h"
17
18 /*
19  * Locked by irq_lock in arch/um/kernel/irq.c.  Changed by os_create_pollfd
20  * and os_free_irq_by_cb, which are called under irq_lock.
21  */
22 static struct pollfd *pollfds = NULL;
23 static int pollfds_num = 0;
24 static int pollfds_size = 0;
25
26 int os_waiting_for_events(struct irq_fd *active_fds)
27 {
28         struct irq_fd *irq_fd;
29         int i, n, err;
30
31         n = poll(pollfds, pollfds_num, 0);
32         if (n < 0) {
33                 err = -errno;
34                 if (errno != EINTR)
35                         printk(UM_KERN_ERR "os_waiting_for_events:"
36                                " poll returned %d, errno = %d\n", n, errno);
37                 return err;
38         }
39
40         if (n == 0)
41                 return 0;
42
43         irq_fd = active_fds;
44
45         for (i = 0; i < pollfds_num; i++) {
46                 if (pollfds[i].revents != 0) {
47                         irq_fd->current_events = pollfds[i].revents;
48                         pollfds[i].fd = -1;
49                 }
50                 irq_fd = irq_fd->next;
51         }
52         return n;
53 }
54
55 int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
56 {
57         if (pollfds_num == pollfds_size) {
58                 if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
59                         /* return min size needed for new pollfds area */
60                         return (pollfds_size + 1) * sizeof(pollfds[0]);
61                 }
62
63                 if (pollfds != NULL) {
64                         memcpy(tmp_pfd, pollfds,
65                                sizeof(pollfds[0]) * pollfds_size);
66                         /* remove old pollfds */
67                         kfree(pollfds);
68                 }
69                 pollfds = tmp_pfd;
70                 pollfds_size++;
71         } else
72                 kfree(tmp_pfd); /* remove not used tmp_pfd */
73
74         pollfds[pollfds_num] = ((struct pollfd) { .fd           = fd,
75                                                   .events       = events,
76                                                   .revents      = 0 });
77         pollfds_num++;
78
79         return 0;
80 }
81
82 void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
83                 struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
84 {
85         struct irq_fd **prev;
86         int i = 0;
87
88         prev = &active_fds;
89         while (*prev != NULL) {
90                 if ((*test)(*prev, arg)) {
91                         struct irq_fd *old_fd = *prev;
92                         if ((pollfds[i].fd != -1) &&
93                             (pollfds[i].fd != (*prev)->fd)) {
94                                 printk(UM_KERN_ERR "os_free_irq_by_cb - "
95                                        "mismatch between active_fds and "
96                                        "pollfds, fd %d vs %d\n",
97                                        (*prev)->fd, pollfds[i].fd);
98                                 goto out;
99                         }
100
101                         pollfds_num--;
102
103                         /*
104                          * This moves the *whole* array after pollfds[i]
105                          * (though it doesn't spot as such)!
106                          */
107                         memmove(&pollfds[i], &pollfds[i + 1],
108                                (pollfds_num - i) * sizeof(pollfds[0]));
109                         if (*last_irq_ptr2 == &old_fd->next)
110                                 *last_irq_ptr2 = prev;
111
112                         *prev = (*prev)->next;
113                         if (old_fd->type == IRQ_WRITE)
114                                 ignore_sigio_fd(old_fd->fd);
115                         kfree(old_fd);
116                         continue;
117                 }
118                 prev = &(*prev)->next;
119                 i++;
120         }
121  out:
122         return;
123 }
124
125 int os_get_pollfd(int i)
126 {
127         return pollfds[i].fd;
128 }
129
130 void os_set_pollfd(int i, int fd)
131 {
132         pollfds[i].fd = fd;
133 }
134
135 void os_set_ioignore(void)
136 {
137         signal(SIGIO, SIG_IGN);
138 }