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 "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"
21
22/*
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.
25 */
26static struct pollfd *pollfds = NULL;
27static int pollfds_num = 0;
28static int pollfds_size = 0;
29
30int os_waiting_for_events(struct irq_fd *active_fds)
31{
32	struct irq_fd *irq_fd;
33	int i, n, err;
34
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;
42	}
43
44	if (n == 0)
45		return 0;
46
47	irq_fd = active_fds;
48
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;
53		}
54		irq_fd = irq_fd->next;
55	}
56	return n;
57}
58
59int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
60{
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]);
65		}
66
67		if (pollfds != NULL) {
68			memcpy(tmp_pfd, pollfds,
69			       sizeof(pollfds[0]) * pollfds_size);
70			/* remove old pollfds */
71			kfree(pollfds);
72		}
73		pollfds = tmp_pfd;
74		pollfds_size++;
75	} else
76		kfree(tmp_pfd);	/* remove not used tmp_pfd */
77
78	pollfds[pollfds_num] = ((struct pollfd) { .fd		= fd,
79						  .events	= events,
80						  .revents	= 0 });
81	pollfds_num++;
82
83	return 0;
84}
85
86void 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)
88{
89	struct irq_fd **prev;
90	int i = 0;
91
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;
102			}
103
104			pollfds_num--;
105
106			/* This moves the *whole* array after pollfds[i]
107			 * (though it doesn't spot as such)!
108			 */
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;
113
114			*prev = (*prev)->next;
115			if(old_fd->type == IRQ_WRITE)
116				ignore_sigio_fd(old_fd->fd);
117			kfree(old_fd);
118			continue;
119		}
120		prev = &(*prev)->next;
121		i++;
122	}
123 out:
124	return;
125}
126
127int os_get_pollfd(int i)
128{
129	return pollfds[i].fd;
130}
131
132void os_set_pollfd(int i, int fd)
133{
134	pollfds[i].fd = fd;
135}
136
137void os_set_ioignore(void)
138{
139	signal(SIGIO, SIG_IGN);
140}
141
142void init_irq_signals(int on_sigstack)
143{
144	int flags;
145
146	flags = on_sigstack ? SA_ONSTACK : 0;
147
148	set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
149		    flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
150	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
151		    flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
152	set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
153		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
154	signal(SIGWINCH, SIG_IGN);
155}
156