tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
23static struct pollfd *pollfds = NULL;
24static int pollfds_num = 0;
25static int pollfds_size = 0;
26
27int 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
56int 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
83void 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
124int os_get_pollfd(int i)
125{
126 return pollfds[i].fd;
127}
128
129void os_set_pollfd(int i, int fd)
130{
131 pollfds[i].fd = fd;
132}
133
134void os_set_ioignore(void)
135{
136 signal(SIGIO, SIG_IGN);
137}
138
139void 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}