vt.c

powerpc内核mpc8241linux系统下char驱动程序

			return i;
		get_user(ll, &vtsizes->v_rows);
		get_user(cc, &vtsizes->v_cols);
		return vc_resize_all(ll, cc);
	}

	case VT_RESIZEX:
	{
		struct vt_consize *vtconsize = (struct vt_consize *) arg;
		ushort ll,cc,vlin,clin,vcol,ccol;
		if (!perm)
			return -EPERM;
		i = verify_area(VERIFY_READ, (void *)vtconsize, sizeof(struct vt_consize));
		if (i)
			return i;
		get_user(ll, &vtconsize->v_rows);
		get_user(cc, &vtconsize->v_cols);
		get_user(vlin, &vtconsize->v_vlin);
		get_user(clin, &vtconsize->v_clin);
		get_user(vcol, &vtconsize->v_vcol);
		get_user(ccol, &vtconsize->v_ccol);
		vlin = vlin ? vlin : video_scan_lines;
		if ( clin )
		  {
		    if ( ll )
		      {
			if ( ll != vlin/clin )
			  return -EINVAL; /* Parameters don't add up */
		      }
		    else 
		      ll = vlin/clin;
		  }
		if ( vcol && ccol )
		  {
		    if ( cc )
		      {
			if ( cc != vcol/ccol )
			  return -EINVAL;
		      }
		    else
		      cc = vcol/ccol;
		  }

		if ( clin > 32 )
		  return -EINVAL;
		    
		if ( vlin )
		  video_scan_lines = vlin;
		if ( clin )
		  video_font_height = clin;
		
		return vc_resize_all(ll, cc);
  	}

	case PIO_FONT: {
		struct console_font_op op;
		if (!perm)
			return -EPERM;
		op.op = KD_FONT_OP_SET;
		op.flags = KD_FONT_FLAG_OLD | KD_FONT_FLAG_DONT_RECALC;	/* Compatibility */
		op.width = 8;
		op.height = 0;
		op.charcount = 256;
		op.data = (char *) arg;
		return con_font_op(fg_console, &op);
	}

	case GIO_FONT: {
		struct console_font_op op;
		op.op = KD_FONT_OP_GET;
		op.flags = KD_FONT_FLAG_OLD;
		op.width = 8;
		op.height = 32;
		op.charcount = 256;
		op.data = (char *) arg;
		return con_font_op(fg_console, &op);
	}

	case PIO_CMAP:
                if (!perm)
			return -EPERM;
                return con_set_cmap((char *)arg);

	case GIO_CMAP:
                return con_get_cmap((char *)arg);

	case PIO_FONTX:
	case GIO_FONTX:
		return do_fontx_ioctl(cmd, (struct consolefontdesc *)arg, perm);

	case PIO_FONTRESET:
	{
		if (!perm)
			return -EPERM;

#ifdef BROKEN_GRAPHICS_PROGRAMS
		/* With BROKEN_GRAPHICS_PROGRAMS defined, the default
		   font is not saved. */
		return -ENOSYS;
#else
		{
		struct console_font_op op;
		op.op = KD_FONT_OP_SET_DEFAULT;
		op.data = NULL;
		i = con_font_op(fg_console, &op);
		if (i) return i;
		con_set_default_unimap(fg_console);
		return 0;
		}
#endif
	}

	case KDFONTOP: {
		struct console_font_op op;
		if (copy_from_user(&op, (void *) arg, sizeof(op)))
			return -EFAULT;
		if (!perm && op.op != KD_FONT_OP_GET)
			return -EPERM;
		i = con_font_op(console, &op);
		if (i) return i;
		if (copy_to_user((void *) arg, &op, sizeof(op)))
			return -EFAULT;
		return 0;
	}

	case PIO_SCRNMAP:
		if (!perm)
			return -EPERM;
		return con_set_trans_old((unsigned char *)arg);

	case GIO_SCRNMAP:
		return con_get_trans_old((unsigned char *)arg);

	case PIO_UNISCRNMAP:
		if (!perm)
			return -EPERM;
		return con_set_trans_new((unsigned short *)arg);

	case GIO_UNISCRNMAP:
		return con_get_trans_new((unsigned short *)arg);

	case PIO_UNIMAPCLR:
	      { struct unimapinit ui;
		if (!perm)
			return -EPERM;
		i = copy_from_user(&ui, (void *)arg, sizeof(struct unimapinit));
		if (i) return -EFAULT;
		con_clear_unimap(fg_console, &ui);
		return 0;
	      }

	case PIO_UNIMAP:
	case GIO_UNIMAP:
		return do_unimap_ioctl(cmd, (struct unimapdesc *)arg, perm);

	case VT_LOCKSWITCH:
		if (!suser())
		   return -EPERM;
		vt_dont_switch = 1;
		return 0;
	case VT_UNLOCKSWITCH:
		if (!suser())
		   return -EPERM;
		vt_dont_switch = 0;
		return 0;
#ifdef CONFIG_FB_COMPAT_XPMAC
	case VC_GETMODE:
		{
			struct vc_mode mode;

			i = verify_area(VERIFY_WRITE, (void *) arg,
					sizeof(struct vc_mode));
			if (i == 0)
				i = console_getmode(&mode);
			if (i)
				return i;
			if (copy_to_user((void *) arg, &mode, sizeof(mode)))
				return -EFAULT;
			return 0;
		}
	case VC_SETMODE:
	case VC_INQMODE:
		{
			struct vc_mode mode;

			if (!perm)
				return -EPERM;
			i = verify_area(VERIFY_READ, (void *) arg,
					sizeof(struct vc_mode));
			if (i)
				return i;
			if (copy_from_user(&mode, (void *) arg, sizeof(mode)))
				return -EFAULT;
			return console_setmode(&mode, cmd == VC_SETMODE);
		}
	case VC_SETCMAP:
		{
			unsigned char cmap[3][256], *p;
			int n_entries, cmap_size, i, j;

			if (!perm)
				return -EPERM;
			if (arg == (unsigned long) VC_POWERMODE_INQUIRY
			    || arg <= VESA_POWERDOWN) {
				/* compatibility hack: VC_POWERMODE
				   was changed from 0x766a to 0x766c */
				return console_powermode((int) arg);
			}
			i = verify_area(VERIFY_READ, (void *) arg,
					sizeof(int));
			if (i)
				return i;
			if (get_user(cmap_size, (int *) arg))
				return -EFAULT;
			if (cmap_size % 3)
				return -EINVAL;
			n_entries = cmap_size / 3;
			if ((unsigned) n_entries > 256)
				return -EINVAL;
			p = (unsigned char *) (arg + sizeof(int));
			for (j = 0; j < n_entries; ++j)
				for (i = 0; i < 3; ++i)
					if (get_user(cmap[i][j], p++))
						return -EFAULT;
			return console_setcmap(n_entries, cmap[0],
					       cmap[1], cmap[2]);
		}
	case VC_GETCMAP:
		/* not implemented yet */
		return -ENOIOCTLCMD;
	case VC_POWERMODE:
		if (!perm)
			return -EPERM;
		return console_powermode((int) arg);
#endif /* CONFIG_FB_COMPAT_XPMAC */
	default:
		return -ENOIOCTLCMD;
	}
}

/*
 * 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 struct wait_queue *vt_activate_queue = NULL;

/*
 * Sleeps until a vt is activated, or the task is interrupted. Returns
 * 0 if activation, -EINTR if interrupted.
 */
int vt_waitactive(int vt)
{
	int retval;
	struct wait_queue wait = { current, NULL };

	add_wait_queue(&vt_activate_queue, &wait);
	for (;;) {
		current->state = TASK_INTERRUPTIBLE;
		retval = 0;
		if (vt == fg_console)
			break;
		retval = -EINTR;
		if (signal_pending(current))
			break;
		schedule();
	}
	remove_wait_queue(&vt_activate_queue, &wait);
	current->state = TASK_RUNNING;
	return retval;
}

#define vt_wake_waitactive() wake_up(&vt_activate_queue)

void reset_vc(unsigned int new_console)
{
	vt_cons[new_console]->vc_mode = KD_TEXT;
	kbd_table[new_console].kbdmode = VC_XLATE;
	vt_cons[new_console]->vt_mode.mode = VT_AUTO;
	vt_cons[new_console]->vt_mode.waitv = 0;
	vt_cons[new_console]->vt_mode.relsig = 0;
	vt_cons[new_console]->vt_mode.acqsig = 0;
	vt_cons[new_console]->vt_mode.frsig = 0;
	vt_cons[new_console]->vt_pid = -1;
	vt_cons[new_console]->vt_newvt = -1;
	reset_palette (new_console) ;
}

/*
 * Performs the back end of a vt switch
 */
void complete_change_console(unsigned int new_console)
{
	unsigned char old_vc_mode;

	last_console = fg_console;

	/*
	 * If we're switching, we could be going from KD_GRAPHICS to
	 * KD_TEXT mode or vice versa, which means we need to blank or
	 * unblank the screen later.
	 */
	old_vc_mode = vt_cons[fg_console]->vc_mode;
	switch_screen(new_console);

	/*
	 * If this new console is under process control, send it a signal
	 * telling it that it has acquired. Also check if it has died and
	 * clean up (similar to logic employed in change_console())
	 */
	if (vt_cons[new_console]->vt_mode.mode == VT_PROCESS)
	{
		/*
		 * Send the signal as privileged - kill_proc() will
		 * tell us if the process has gone or something else
		 * is awry
		 */
		if (kill_proc(vt_cons[new_console]->vt_pid,
			      vt_cons[new_console]->vt_mode.acqsig,
			      1) != 0)
		{
		/*
		 * The controlling process has died, so we revert back to
		 * normal operation. In this case, we'll also change back
		 * to KD_TEXT mode. I'm not sure if this is strictly correct
		 * but it saves the agony when the X server dies and the screen
		 * remains blanked due to KD_GRAPHICS! It would be nice to do
		 * this outside of VT_PROCESS but there is no single process
		 * to account for and tracking tty count may be undesirable.
		 */
		        reset_vc(new_console);
		}
	}

	/*
	 * We do this here because the controlling process above may have
	 * gone, and so there is now a new vc_mode
	 */
	if (old_vc_mode != vt_cons[new_console]->vc_mode)
	{
		if (vt_cons[new_console]->vc_mode == KD_TEXT)
			unblank_screen();
		else
			do_blank_screen(1);
	}

	/*
	 * Wake anyone waiting for their VT to activate
	 */
	vt_wake_waitactive();
	return;
}

/*
 * Performs the front-end of a vt switch
 */
void change_console(unsigned int new_console)
{
        if ((new_console == fg_console) || (vt_dont_switch))
                return;
        if (!vc_cons_allocated(new_console))
		return;

	/*
	 * If this vt is in process mode, then we need to handshake with
	 * that process before switching. Essentially, we store where that
	 * vt wants to switch to and wait for it to tell us when it's done
	 * (via VT_RELDISP ioctl).
	 *
	 * We also check to see if the controlling process still exists.
	 * If it doesn't, we reset this vt to auto mode and continue.
	 * This is a cheap way to track process control. The worst thing
	 * that can happen is: we send a signal to a process, it dies, and
	 * the switch gets "lost" waiting for a response; hopefully, the
	 * user will try again, we'll detect the process is gone (unless
	 * the user waits just the right amount of time :-) and revert the
	 * vt to auto control.
	 */
	if (vt_cons[fg_console]->vt_mode.mode == VT_PROCESS)
	{
		/*
		 * Send the signal as privileged - kill_proc() will
		 * tell us if the process has gone or something else
		 * is awry
		 */
		if (kill_proc(vt_cons[fg_console]->vt_pid,
			      vt_cons[fg_console]->vt_mode.relsig,
			      1) == 0)
		{
			/*
			 * It worked. Mark the vt to switch to and
			 * return. The process needs to send us a
			 * VT_RELDISP ioctl to complete the switch.
			 */
			vt_cons[fg_console]->vt_newvt = new_console;
			return;
		}

		/*
		 * The controlling process has died, so we revert back to
		 * normal operation. In this case, we'll also change back
		 * to KD_TEXT mode. I'm not sure if this is strictly correct
		 * but it saves the agony when the X server dies and the screen
		 * remains blanked due to KD_GRAPHICS! It would be nice to do
		 * this outside of VT_PROCESS but there is no single process
		 * to account for and tracking tty count may be undesirable.
		 */
		reset_vc(fg_console);

		/*
		 * Fall through to normal (VT_AUTO) handling of the switch...
		 */
	}

	/*
	 * Ignore all switches in KD_GRAPHICS+VT_AUTO mode
	 */
	if (vt_cons[fg_console]->vc_mode == KD_GRAPHICS)
		return;

	complete_change_console(new_console);
}