Revert "Fix very high interrupt rate for IRQ8 (rtc) unless pnpacpi=off"
[pv_ops_mirror.git] / arch / um / os-Linux / irq.c
blob6aa6f95d652491ab4e1161247febeaa1c91856c1
1 /*
2 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
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 "kern_util.h"
15 #include "user.h"
16 #include "process.h"
17 #include "sigio.h"
18 #include "irq_user.h"
19 #include "os.h"
20 #include "um_malloc.h"
23 * Locked by irq_lock in arch/um/kernel/irq.c. Changed by os_create_pollfd
24 * and os_free_irq_by_cb, which are called under irq_lock.
26 static struct pollfd *pollfds = NULL;
27 static int pollfds_num = 0;
28 static int pollfds_size = 0;
30 int os_waiting_for_events(struct irq_fd *active_fds)
32 struct irq_fd *irq_fd;
33 int i, n, err;
35 n = poll(pollfds, pollfds_num, 0);
36 if (n < 0) {
37 err = -errno;
38 if (errno != EINTR)
39 printk("sigio_handler: os_waiting_for_events:"
40 " poll returned %d, errno = %d\n", n, errno);
41 return err;
44 if (n == 0)
45 return 0;
47 irq_fd = active_fds;
49 for (i = 0; i < pollfds_num; i++) {
50 if (pollfds[i].revents != 0) {
51 irq_fd->current_events = pollfds[i].revents;
52 pollfds[i].fd = -1;
54 irq_fd = irq_fd->next;
56 return n;
59 int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
61 if (pollfds_num == pollfds_size) {
62 if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
63 /* return min size needed for new pollfds area */
64 return (pollfds_size + 1) * sizeof(pollfds[0]);
67 if (pollfds != NULL) {
68 memcpy(tmp_pfd, pollfds,
69 sizeof(pollfds[0]) * pollfds_size);
70 /* remove old pollfds */
71 kfree(pollfds);
73 pollfds = tmp_pfd;
74 pollfds_size++;
75 } else
76 kfree(tmp_pfd); /* remove not used tmp_pfd */
78 pollfds[pollfds_num] = ((struct pollfd) { .fd = fd,
79 .events = events,
80 .revents = 0 });
81 pollfds_num++;
83 return 0;
86 void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
87 struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
89 struct irq_fd **prev;
90 int i = 0;
92 prev = &active_fds;
93 while (*prev != NULL) {
94 if ((*test)(*prev, arg)) {
95 struct irq_fd *old_fd = *prev;
96 if ((pollfds[i].fd != -1) &&
97 (pollfds[i].fd != (*prev)->fd)) {
98 printk("os_free_irq_by_cb - mismatch between "
99 "active_fds and pollfds, fd %d vs %d\n",
100 (*prev)->fd, pollfds[i].fd);
101 goto out;
104 pollfds_num--;
106 /* This moves the *whole* array after pollfds[i]
107 * (though it doesn't spot as such)!
109 memmove(&pollfds[i], &pollfds[i + 1],
110 (pollfds_num - i) * sizeof(pollfds[0]));
111 if(*last_irq_ptr2 == &old_fd->next)
112 *last_irq_ptr2 = prev;
114 *prev = (*prev)->next;
115 if(old_fd->type == IRQ_WRITE)
116 ignore_sigio_fd(old_fd->fd);
117 kfree(old_fd);
118 continue;
120 prev = &(*prev)->next;
121 i++;
123 out:
124 return;
127 int os_get_pollfd(int i)
129 return pollfds[i].fd;
132 void os_set_pollfd(int i, int fd)
134 pollfds[i].fd = fd;
137 void os_set_ioignore(void)
139 signal(SIGIO, SIG_IGN);
142 void init_irq_signals(int on_sigstack)
144 int flags;
146 flags = on_sigstack ? SA_ONSTACK : 0;
148 set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
149 SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
150 signal(SIGWINCH, SIG_IGN);