diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/vt.c | 4 | ||||
| -rw-r--r-- | drivers/char/vt_ioctl.c | 185 |
2 files changed, 138 insertions, 51 deletions
diff --git a/drivers/char/vt.c b/drivers/char/vt.c index e47a4c88976..33214d92ca4 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -252,7 +252,6 @@ static void notify_update(struct vc_data *vc) struct vt_notifier_param param = { .vc = vc }; atomic_notifier_call_chain(&vt_notifier_list, VT_UPDATE, ¶m); } - /* * Low-Level Functions */ @@ -935,6 +934,7 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc, if (CON_IS_VISIBLE(vc)) update_screen(vc); + vt_event_post(VT_EVENT_RESIZE, vc->vc_num, vc->vc_num); return err; } @@ -3637,6 +3637,7 @@ void do_blank_screen(int entering_gfx) blank_state = blank_vesa_wait; mod_timer(&console_timer, jiffies + vesa_off_interval); } + vt_event_post(VT_EVENT_BLANK, vc->vc_num, vc->vc_num); } EXPORT_SYMBOL(do_blank_screen); @@ -3681,6 +3682,7 @@ void do_unblank_screen(int leaving_gfx) console_blank_hook(0); set_palette(vc); set_cursor(vc); + vt_event_post(VT_EVENT_UNBLANK, vc->vc_num, vc->vc_num); } EXPORT_SYMBOL(do_unblank_screen); diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c index 95189f288f8..35ad94e65d0 100644 --- a/drivers/char/vt_ioctl.c +++ b/drivers/char/vt_ioctl.c @@ -62,6 +62,133 @@ extern struct tty_driver *console_driver; 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 */ @@ -360,6 +487,8 @@ do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud, int perm, struct vc_ return 0; } + + /* * We handle the console-specific ioctl's here. We allow the * capability to modify any console, not just the fg_console. @@ -851,7 +980,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, if (arg == 0 || arg > MAX_NR_CONSOLES) ret = -ENXIO; else - ret = vt_waitactive(arg - 1); + ret = vt_waitactive(arg); break; /* @@ -1159,6 +1288,9 @@ int vt_ioctl(struct tty_struct *tty, struct file * file, 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; } @@ -1170,54 +1302,6 @@ eperm: 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; @@ -1262,6 +1346,7 @@ void vc_SAK(struct work_struct *work) static void complete_change_console(struct vc_data *vc) { unsigned char old_vc_mode; + int old = fg_console; last_console = fg_console; @@ -1325,7 +1410,7 @@ static void complete_change_console(struct vc_data *vc) /* * Wake anyone waiting for their VT to activate */ - vt_wake_waitactive(); + vt_event_post(VT_EVENT_SWITCH, old, vc->vc_num); return; } |