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 */
19static struct pollfd *pollfds = NULL;
20static int pollfds_num = 0;
21static int pollfds_size = 0;
22
23int 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
52int 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
79void 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
122int os_get_pollfd(int i)
123{
124	return pollfds[i].fd;
125}
126
127void os_set_pollfd(int i, int fd)
128{
129	pollfds[i].fd = fd;
130}
131
132void os_set_ioignore(void)
133{
134	signal(SIGIO, SIG_IGN);
135}
136