irq.c
2.81 KB
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/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <errno.h>
#include <poll.h>
#include <signal.h>
#include <string.h>
#include <irq_user.h>
#include <os.h>
#include <um_malloc.h>
/*
* Locked by irq_lock in arch/um/kernel/irq.c. Changed by os_create_pollfd
* and os_free_irq_by_cb, which are called under irq_lock.
*/
static struct pollfd *pollfds = NULL;
static int pollfds_num = 0;
static int pollfds_size = 0;
int os_waiting_for_events(struct irq_fd *active_fds)
{
struct irq_fd *irq_fd;
int i, n, err;
n = poll(pollfds, pollfds_num, 0);
if (n < 0) {
err = -errno;
if (errno != EINTR)
printk(UM_KERN_ERR "os_waiting_for_events:"
" poll returned %d, errno = %d\n", n, errno);
return err;
}
if (n == 0)
return 0;
irq_fd = active_fds;
for (i = 0; i < pollfds_num; i++) {
if (pollfds[i].revents != 0) {
irq_fd->current_events = pollfds[i].revents;
pollfds[i].fd = -1;
}
irq_fd = irq_fd->next;
}
return n;
}
int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
{
if (pollfds_num == pollfds_size) {
if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
/* return min size needed for new pollfds area */
return (pollfds_size + 1) * sizeof(pollfds[0]);
}
if (pollfds != NULL) {
memcpy(tmp_pfd, pollfds,
sizeof(pollfds[0]) * pollfds_size);
/* remove old pollfds */
kfree(pollfds);
}
pollfds = tmp_pfd;
pollfds_size++;
} else
kfree(tmp_pfd); /* remove not used tmp_pfd */
pollfds[pollfds_num] = ((struct pollfd) { .fd = fd,
.events = events,
.revents = 0 });
pollfds_num++;
return 0;
}
void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
{
struct irq_fd **prev;
int i = 0;
prev = &active_fds;
while (*prev != NULL) {
if ((*test)(*prev, arg)) {
struct irq_fd *old_fd = *prev;
if ((pollfds[i].fd != -1) &&
(pollfds[i].fd != (*prev)->fd)) {
printk(UM_KERN_ERR "os_free_irq_by_cb - "
"mismatch between active_fds and "
"pollfds, fd %d vs %d\n",
(*prev)->fd, pollfds[i].fd);
goto out;
}
pollfds_num--;
/*
* This moves the *whole* array after pollfds[i]
* (though it doesn't spot as such)!
*/
memmove(&pollfds[i], &pollfds[i + 1],
(pollfds_num - i) * sizeof(pollfds[0]));
if (*last_irq_ptr2 == &old_fd->next)
*last_irq_ptr2 = prev;
*prev = (*prev)->next;
if (old_fd->type == IRQ_WRITE)
ignore_sigio_fd(old_fd->fd);
kfree(old_fd);
continue;
}
prev = &(*prev)->next;
i++;
}
out:
return;
}
int os_get_pollfd(int i)
{
return pollfds[i].fd;
}
void os_set_pollfd(int i, int fd)
{
pollfds[i].fd = fd;
}
void os_set_ioignore(void)
{
signal(SIGIO, SIG_IGN);
}