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