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 #include "um_malloc.h"
  22
  23 static struct pollfd *pollfds = NULL;
  24 static int pollfds_num = 0;
  25 static int pollfds_size = 0;
  26
  27 int os_waiting_for_events(struct irq_fd *active_fds)
  28 {
  29         struct irq_fd *irq_fd;
  30         int i, n, err;
  31
  32         n = poll(pollfds, pollfds_num, 0);
  33         if (n < 0) {
  34                 err = -errno;
  35                 if (errno != EINTR)
  36                         printk("sigio_handler: os_waiting_for_events:"
  37                                " poll returned %d, errno = %d\n", n, errno);
  38                 return err;
  39         }
  40
  41         if (n == 0)
  42                 return 0;
  43
  44         irq_fd = active_fds;
  45
  46         for (i = 0; i < pollfds_num; i++) {
  47                 if (pollfds[i].revents != 0) {
  48                         irq_fd->current_events = pollfds[i].revents;
  49                         pollfds[i].fd = -1;
  50                 }
  51                 irq_fd = irq_fd->next;
  52         }
  53         return n;
  54 }
  55
  56 int os_create_pollfd(int fd, int events, void *tmp_pfd, int size_tmpfds)
  57 {
  58         if (pollfds_num == pollfds_size) {
  59                 if (size_tmpfds <= pollfds_size * sizeof(pollfds[0])) {
  60                         /* return min size needed for new pollfds area */
  61                         return((pollfds_size + 1) * sizeof(pollfds[0]));
  62                 }
  63
  64                 if (pollfds != NULL) {
  65                         memcpy(tmp_pfd, pollfds,
  66                                sizeof(pollfds[0]) * pollfds_size);
  67                         /* remove old pollfds */
  68                         kfree(pollfds);
  69                 }
  70                 pollfds = tmp_pfd;
  71                 pollfds_size++;
  72         } else
  73                 kfree(tmp_pfd); /* remove not used tmp_pfd */
  74
  75         pollfds[pollfds_num] = ((struct pollfd) { .fd           = fd,
  76                                                   .events       = events,
  77                                                   .revents      = 0 });
  78         pollfds_num++;
  79
  80         return 0;
  81 }
  82
  83 void os_free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg,
  84                 struct irq_fd *active_fds, struct irq_fd ***last_irq_ptr2)
  85 {
  86         struct irq_fd **prev;
  87         int i = 0;
  88
  89         prev = &active_fds;
  90         while (*prev != NULL) {
  91                 if ((*test)(*prev, arg)) {
  92                         struct irq_fd *old_fd = *prev;
  93                         if ((pollfds[i].fd != -1) &&
  94                             (pollfds[i].fd != (*prev)->fd)) {
  95                                 printk("os_free_irq_by_cb - mismatch between "
  96                                        "active_fds and pollfds, fd %d vs %d\n",
  97                                        (*prev)->fd, pollfds[i].fd);
  98                                 goto out;
  99                         }
 100
 101                         pollfds_num--;
 102
 103                         /* This moves the *whole* array after pollfds[i]
 104                          * (though it doesn't spot as such)!
 105                          */
 106                         memmove(&pollfds[i], &pollfds[i + 1],
 107                                (pollfds_num - i) * sizeof(pollfds[0]));
 108                         if(*last_irq_ptr2 == &old_fd->next)
 109                                 *last_irq_ptr2 = prev;
 110
 111                         *prev = (*prev)->next;
 112                         if(old_fd->type == IRQ_WRITE)
 113                                 ignore_sigio_fd(old_fd->fd);
 114                         kfree(old_fd);
 115                         continue;
 116                 }
 117                 prev = &(*prev)->next;
 118                 i++;
 119         }
 120  out:
 121         return;
 122 }
 123
 124 int os_get_pollfd(int i)
 125 {
 126         return pollfds[i].fd;
 127 }
 128
 129 void os_set_pollfd(int i, int fd)
 130 {
 131         pollfds[i].fd = fd;
 132 }
 133
 134 void os_set_ioignore(void)
 135 {
 136         signal(SIGIO, SIG_IGN);
 137 }
 138
 139 void init_irq_signals(int on_sigstack)
 140 {
 141         int flags;
 142
 143         flags = on_sigstack ? SA_ONSTACK : 0;
 144
 145         set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
 146                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
 147         set_handler(SIGALRM, (__sighandler_t) alarm_handler,
 148                     flags | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, -1);
 149         set_handler(SIGIO, (__sighandler_t) sig_handler, flags | SA_RESTART,
 150                     SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
 151         signal(SIGWINCH, SIG_IGN);
 152 }