gnumach/oskit ds_osenv.c osenv_irq.c

[Roland McGrath]

CVSROOT:        /cvsroot/hurd
Module name:    gnumach
Changes by:     Roland McGrath <address@hidden> 03/02/28 03:55:19

Modified files:
        oskit          : ds_osenv.c osenv_irq.c 

Log message:
        2003-02-28  Roland McGrath  <address@hidden>
        
        * oskit/osenv_irq.c (console_irq, console_irq_handler): New variables.
        (irq_alloc, irq_free): Implement special kludge with console_irq.
        * oskit/ds_osenv.c (ds_osenv_init): Set console_irq before
        initializing the minimal interrupt-driven console.

CVSWeb URLs:
http://savannah.gnu.org/cgi-bin/viewcvs/gnumach/gnumach/oskit/ds_osenv.c.diff?tr1=1.2&tr2=1.3&r1=text&r2=text
http://savannah.gnu.org/cgi-bin/viewcvs/gnumach/gnumach/oskit/osenv_irq.c.diff?tr1=1.2&tr2=1.3&r1=text&r2=text

Patches:
Index: gnumach/oskit/ds_osenv.c
diff -u gnumach/oskit/ds_osenv.c:1.2 gnumach/oskit/ds_osenv.c:1.3
--- gnumach/oskit/ds_osenv.c:1.2        Mon May 27 19:01:57 2002
+++ gnumach/oskit/ds_osenv.c    Fri Feb 28 03:55:18 2003
@@ -16,6 +16,8 @@
 
 oskit_stream_t *ds_console_stream;
 
+extern int console_irq;                /* kludge in osenv_irq.c */
+
 
 void
 ds_osenv_init (void)
@@ -44,6 +46,7 @@
       param.c_lflag &= ~ECHO;
       param.c_iflag &= ~ICRNL;
       param.c_oflag &= ~OPOST;
+      console_irq = -1;
       rc = cq_com_console_init (port, &param,
                                oskit_create_osenv_irq (),
                                intr,
@@ -53,6 +56,7 @@
   else
     {
       oskit_osenv_intr_t *intr = oskit_create_osenv_intr ();
+      console_irq = -1;
       rc = cq_direct_console_init (oskit_create_osenv_irq (),
                                   intr,
                                   oskit_create_osenv_sleep (intr),
Index: gnumach/oskit/osenv_irq.c
diff -u gnumach/oskit/osenv_irq.c:1.2 gnumach/oskit/osenv_irq.c:1.3
--- gnumach/oskit/osenv_irq.c:1.2       Mon May 27 19:01:57 2002
+++ gnumach/oskit/osenv_irq.c   Fri Feb 28 03:55:18 2003
@@ -118,6 +118,16 @@
        return 1;
 }
 
+
+/* This is a special kludge for the minimal console.  If console_irq is -1
+   during the first irq_alloc, we set it to the irq being allocated.
+   Thereafter, allocating that irq will silently succeed and override
+   the handler installed for the minimal console, which we save in
+   console_irq_handler; freeing that irq will restore the console handler.  */
+
+int console_irq;
+static struct int_handler *console_irq_handler;
+
 static OSKIT_COMDECL_U
 irq_alloc(oskit_osenv_irq_t *o, int irq,
          void (*handler)(void *), void *data, int flags)
@@ -153,6 +163,29 @@
        temp->data = data;
        temp->next = NULL;
 
+       /* Special hack for the minimal com and direct console devices.  */
+       if (console_irq == -1) {
+               /* ds_osenv_init sets console_irq to -1 while initializing the
+                  console, so we know this is the irq being allocated for it.
+                  XXX we assume there is only one!
+               */
+               assert (first_time);
+               console_irq = irq;
+       }
+       else if (irq == console_irq && console_irq_handler == NULL) {
+               /* Attempting to re-allocate the console's irq.
+                  This must be a real device driver taking over
+                  from the minimal console.  Let it.  */
+               assert (! first_time);
+               assert (handlers[irq] != NULL);
+               console_irq_handler = handlers[irq];
+               osenv_log(OSENV_LOG_DEBUG,
+                         "irq %d stolen from console\n", irq);
+               handlers[irq] = temp;
+               shareable[irq] = (flags & OSENV_IRQ_SHAREABLE) != 0;
+               return 0;
+       }
+
        /*
         * Fail if the irq is already in use
         * and either the new handler or the existing handler
@@ -208,11 +241,27 @@
        if (temp != NULL &&
            temp->func == handler && temp->data == data &&
            temp->next == NULL) {
-               osenv_irq_disable(irq);
-               handlers[irq] = NULL;
-               intpri[irq] = SPL0;
-               ivect[irq] = intnull;
-               iunit[irq] = irq;
+               if (irq == console_irq) {
+                       /* Special hack for the minimal console's irq.
+                          Restore the console's handler now that no real
+                          driver is using it.
+                          XXX this is probably not actually useful since
+                          the driver won't have left the device in the same
+                          state the minimal console driver expects.
+                       */
+                       handlers[irq] = console_irq_handler;
+                       shareable[irq] = 0;
+                       console_irq_handler = NULL;
+                       osenv_log(OSENV_LOG_DEBUG,
+                                 "irq %d returned to console\n", irq);
+               }
+               else {
+                       osenv_irq_disable(irq);
+                       handlers[irq] = NULL;
+                       intpri[irq] = SPL0;
+                       ivect[irq] = intnull;
+                       iunit[irq] = irq;
+               }
                kfree(temp, sizeof(struct int_handler));
                return;
        }