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/arch/um/os-Linux/irq.c

https://bitbucket.org/thekraven/iscream_thunderc-2.6.35
C | 138 lines | 105 code | 19 blank | 14 comment | 23 complexity | b397fdd82a5946cf10d7023e2a009778 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  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 "kern_constants.h"
 13#include "os.h"
 14#include "process.h"
 15#include "um_malloc.h"
 16#include "user.h"
 17
 18/*
 19 * Locked by irq_lock in arch/um/kernel/irq.c.  Changed by os_create_pollfd
 20 * and os_free_irq_by_cb, which are called under irq_lock.
 21 */
 22static struct pollfd *pollfds = NULL;
 23static int pollfds_num = 0;
 24static int pollfds_size = 0;
 25
 26int os_waiting_for_events(struct irq_fd *active_fds)
 27{
 28	struct irq_fd *irq_fd;
 29	int i, n, err;
 30
 31	n = poll(pollfds, pollfds_num, 0);
 32	if (n < 0) {
 33		err = -errno;
 34		if (errno != EINTR)
 35			printk(UM_KERN_ERR "os_waiting_for_events:"
 36			       " poll returned %d, errno = %d\n", n, errno);
 37		return err;
 38	}
 39
 40	if (n == 0)
 41		return 0;
 42
 43	irq_fd = active_fds;
 44
 45	for (i = 0; i < pollfds_num; i++) {
 46		if (pollfds[i].revents != 0) {
 47			irq_fd->current_events = pollfds[i].revents;
 48			pollfds[i].fd = -1;
 49		}
 50		irq_fd = irq_fd->next;
 51	}
 52	return n;
 53}
 54
 55int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
 56{
 57	if (pollfds_num == pollfds_size) {
 58		if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
 59			/* return min size needed for new pollfds area */
 60			return (pollfds_size + 1) * sizeof(pollfds[0]);
 61		}
 62
 63		if (pollfds != NULL) {
 64			memcpy(tmp_pfd, pollfds,
 65			       sizeof(pollfds[0]) * pollfds_size);
 66			/* remove old pollfds */
 67			kfree(pollfds);
 68		}
 69		pollfds = tmp_pfd;
 70		pollfds_size++;
 71	} else
 72		kfree(tmp_pfd);	/* remove not used tmp_pfd */
 73
 74	pollfds[pollfds_num] = ((struct pollfd) { .fd		= fd,
 75						  .events	= events,
 76						  .revents	= 0 });
 77	pollfds_num++;
 78
 79	return 0;
 80}
 81
 82void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
 83		struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
 84{
 85	struct irq_fd **prev;
 86	int i = 0;
 87
 88	prev = &active_fds;
 89	while (*prev != NULL) {
 90		if ((*test)(*prev, arg)) {
 91			struct irq_fd *old_fd = *prev;
 92			if ((pollfds[i].fd != -1) &&
 93			    (pollfds[i].fd != (*prev)->fd)) {
 94				printk(UM_KERN_ERR "os_free_irq_by_cb - "
 95				       "mismatch between active_fds and "
 96				       "pollfds, fd %d vs %d\n",
 97				       (*prev)->fd, pollfds[i].fd);
 98				goto out;
 99			}
100
101			pollfds_num--;
102
103			/*
104			 * This moves the *whole* array after pollfds[i]
105			 * (though it doesn't spot as such)!
106			 */
107			memmove(&pollfds[i], &pollfds[i + 1],
108			       (pollfds_num - i) * sizeof(pollfds[0]));
109			if (*last_irq_ptr2 == &old_fd->next)
110				*last_irq_ptr2 = prev;
111
112			*prev = (*prev)->next;
113			if (old_fd->type == IRQ_WRITE)
114				ignore_sigio_fd(old_fd->fd);
115			kfree(old_fd);
116			continue;
117		}
118		prev = &(*prev)->next;
119		i++;
120	}
121 out:
122	return;
123}
124
125int os_get_pollfd(int i)
126{
127	return pollfds[i].fd;
128}
129
130void os_set_pollfd(int i, int fd)
131{
132	pollfds[i].fd = fd;
133}
134
135void os_set_ioignore(void)
136{
137	signal(SIGIO, SIG_IGN);
138}