arch/um/os-Linux/irq.c

   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 "user_util.h"
  15 #include "kern_util.h"
  16 #include "user.h"
  17 #include "process.h"
  18 #include "sigio.h"
  19 #include "irq_user.h"
  20 #include "os.h"
  21
  22 static struct pollfd *pollfds = NULL;
  23 static int pollfds_num = 0;
  24 static int pollfds_size = 0;
  25
  26 int 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("sigio_handler: 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
  55 int 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
  82 void 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("os_free_irq_by_cb - mismatch between "
  95                                        "active_fds and pollfds, fd %d vs %d\n",
  96                                        (*prev)->fd, pollfds[i].fd);
  97                                 goto out;
  98                         }
  99
 100                         pollfds_num--;
 101
 102                         /* This moves the *whole* array after pollfds[i]
 103                          * (though it doesn't spot as such)!
 104                          */
 105                         memmove(&pollfds[i], &pollfds[i + 1],
 106                                (pollfds_num - i) * sizeof(pollfds[0]));
 107                         if(*last_irq_ptr2 == &old_fd->next)
 108                                 *last_irq_ptr2 = prev;
 109
 110                         *prev = (*prev)->next;
 111                         if(old_fd->type == IRQ_WRITE)
 112                                 ignore_sigio_fd(old_fd->fd);
 113                         kfree(old_fd);
 114                         continue;
 115                 }
 116                 prev = &(*prev)->next;
 117                 i++;
 118         }
 119  out:
 120         return;
 121 }
 122
 123 int os_get_pollfd(int i)
 124 {
 125         return pollfds[i].fd;
 126 }
 127
 128 void os_set_pollfd(int i, int fd)
 129 {
 130         pollfds[i].fd = fd;
 131 }
 132
 133 void os_set_ioignore(void)
 134 {
 135         signal(SIGIO, SIG_IGN);
 136 }
 137
 138 void init_irq_signals(int on_sigstack)
 139 {
 140         int flags;
 141
 142         flags = on_sigstack ? SA_ONSTACK : 0;
 143
 144         set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
 145                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
 146         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
 147                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
 148         set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
 149                     SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
 150         signal(SIGWINCH, SIG_IGN);
 151 }