static void complete_change_console(struct vc_data *vc);
+/*
+ * User space VT_EVENT handlers
+ */
+
+struct vt_event_wait {
+ struct list_head list;
+ struct vt_event event;
+ int done;
+};
+
+static LIST_HEAD(vt_events);
+static DEFINE_SPINLOCK(vt_event_lock);
+static DECLARE_WAIT_QUEUE_HEAD(vt_event_waitqueue);
+
+/**
+ * vt_event_post
+ * @event: the event that occurred
+ * @old: old console
+ * @new: new console
+ *
+ * Post an VT event to interested VT handlers
+ */
+
+void vt_event_post(unsigned int event, unsigned int old, unsigned int new)
+{
+ struct list_head *pos, *head;
+ unsigned long flags;
+ int wake = 0;
+
+ spin_lock_irqsave(&vt_event_lock, flags);
+ head = &vt_events;
+
+ list_for_each(pos, head) {
+ struct vt_event_wait *ve = list_entry(pos,
+ struct vt_event_wait, list);
+ if (!(ve->event.event & event))
+ continue;
+ ve->event.event = event;
+ /* kernel view is consoles 0..n-1, user space view is
+ console 1..n with 0 meaning current, so we must bias */
+ ve->event.old = old + 1;
+ ve->event.new = new + 1;
+ wake = 1;
+ ve->done = 1;
+ }
+ spin_unlock_irqrestore(&vt_event_lock, flags);
+ if (wake)
+ wake_up_interruptible(&vt_event_waitqueue);
+}
+
+/**
+ * vt_event_wait - wait for an event
+ * @vw: our event
+ *
+ * Waits for an event to occur which completes our vt_event_wait
+ * structure. On return the structure has wv->done set to 1 for success
+ * or 0 if some event such as a signal ended the wait.
+ */
+
+static void vt_event_wait(struct vt_event_wait *vw)
+{
+ unsigned long flags;
+ /* Prepare the event */
+ INIT_LIST_HEAD(&vw->list);
+ vw->done = 0;
+ /* Queue our event */
+ spin_lock_irqsave(&vt_event_lock, flags);
+ list_add(&vw->list, &vt_events);
+ spin_unlock_irqrestore(&vt_event_lock, flags);
+ /* Wait for it to pass */
+ wait_event_interruptible(vt_event_waitqueue, vw->done);
+ /* Dequeue it */
+ spin_lock_irqsave(&vt_event_lock, flags);
+ list_del(&vw->list);
+ spin_unlock_irqrestore(&vt_event_lock, flags);
+}
+
+/**
+ * vt_event_wait_ioctl - event ioctl handler
+ * @arg: argument to ioctl
+ *
+ * Implement the VT_WAITEVENT ioctl using the VT event interface
+ */
+
+static int vt_event_wait_ioctl(struct vt_event __user *event)
+{
+ struct vt_event_wait vw;
+
+ if (copy_from_user(&vw.event, event, sizeof(struct vt_event)))
+ return -EFAULT;
+ /* Highest supported event for now */
+ if (vw.event.event & ~VT_MAX_EVENT)
+ return -EINVAL;
+
+ vt_event_wait(&vw);
+ /* If it occurred report it */
+ if (vw.done) {
+ if (copy_to_user(event, &vw.event, sizeof(struct vt_event)))
+ return -EFAULT;
+ return 0;
+ }
+ return -EINTR;
+}
+
+/**
+ * vt_waitactive - active console wait
+ * @event: event code
+ * @n: new console
+ *
+ * Helper for event waits. Used to implement the legacy
+ * event waiting ioctls in terms of events
+ */
+
+int vt_waitactive(int n)
+{
+ struct vt_event_wait vw;
+ do {
+ if (n == fg_console + 1)
+ break;
+ vw.event.event = VT_EVENT_SWITCH;
+ vt_event_wait(&vw);
+ if (vw.done == 0)
+ return -EINTR;
+ } while (vw.event.new != n);
+ return 0;
+}
+
/*
* these are the valid i/o ports we're allowed to change. they map all the
* video ports
return 0;
}
+
+
/*
* We handle the console-specific ioctl's here. We allow the
* capability to modify any console, not just the fg_console.
if (arg == 0 || arg > MAX_NR_CONSOLES)
ret = -ENXIO;
else
- ret = vt_waitactive(arg - 1);
+ ret = vt_waitactive(arg);
break;
/*
ret = put_user(vc->vc_hi_font_mask,
(unsigned short __user *)arg);
break;
+ case VT_WAITEVENT:
+ ret = vt_event_wait_ioctl((struct vt_event __user *)arg);
+ break;
default:
ret = -ENOIOCTLCMD;
}
goto out;
}
-/*
- * Sometimes we want to wait until a particular VT has been activated. We
- * do it in a very simple manner. Everybody waits on a single queue and
- * get woken up at once. Those that are satisfied go on with their business,
- * while those not ready go back to sleep. Seems overkill to add a wait
- * to each vt just for this - usually this does nothing!
- */
-static DECLARE_WAIT_QUEUE_HEAD(vt_activate_queue);
-
-/*
- * Sleeps until a vt is activated, or the task is interrupted. Returns
- * 0 if activation, -EINTR if interrupted by a signal handler.
- */
-int vt_waitactive(int vt)
-{
- int retval;
- DECLARE_WAITQUEUE(wait, current);
-
- add_wait_queue(&vt_activate_queue, &wait);
- for (;;) {
- retval = 0;
-
- /*
- * Synchronize with redraw_screen(). By acquiring the console
- * semaphore we make sure that the console switch is completed
- * before we return. If we didn't wait for the semaphore, we
- * could return at a point where fg_console has already been
- * updated, but the console switch hasn't been completed.
- */
- acquire_console_sem();
- set_current_state(TASK_INTERRUPTIBLE);
- if (vt == fg_console) {
- release_console_sem();
- break;
- }
- release_console_sem();
- retval = -ERESTARTNOHAND;
- if (signal_pending(current))
- break;
- schedule();
- }
- remove_wait_queue(&vt_activate_queue, &wait);
- __set_current_state(TASK_RUNNING);
- return retval;
-}
-
-#define vt_wake_waitactive() wake_up(&vt_activate_queue)
-
void reset_vc(struct vc_data *vc)
{
vc->vc_mode = KD_TEXT;
static void complete_change_console(struct vc_data *vc)
{
unsigned char old_vc_mode;
+ int old = fg_console;
last_console = fg_console;
/*
* Wake anyone waiting for their VT to activate
*/
- vt_wake_waitactive();
+ vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num);
return;
}
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff