freebsd-dev/sys/dev/syscons/scvesactl.c
Ed Schouten bc093719ca Integrate the new MPSAFE TTY layer to the FreeBSD operating system.
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:

- Improved driver model:

  The old TTY layer has a driver model that is not abstract enough to
  make it friendly to use. A good example is the output path, where the
  device drivers directly access the output buffers. This means that an
  in-kernel PPP implementation must always convert network buffers into
  TTY buffers.

  If a PPP implementation would be built on top of the new TTY layer
  (still needs a hooks layer, though), it would allow the PPP
  implementation to directly hand the data to the TTY driver.

- Improved hotplugging:

  With the old TTY layer, it isn't entirely safe to destroy TTY's from
  the system. This implementation has a two-step destructing design,
  where the driver first abandons the TTY. After all threads have left
  the TTY, the TTY layer calls a routine in the driver, which can be
  used to free resources (unit numbers, etc).

  The pts(4) driver also implements this feature, which means
  posix_openpt() will now return PTY's that are created on the fly.

- Improved performance:

  One of the major improvements is the per-TTY mutex, which is expected
  to improve scalability when compared to the old Giant locking.
  Another change is the unbuffered copying to userspace, which is both
  used on TTY device nodes and PTY masters.

Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.

Obtained from:		//depot/projects/mpsafetty/...
Approved by:		philip (ex-mentor)
Discussed:		on the lists, at BSDCan, at the DevSummit
Sponsored by:		Snow B.V., the Netherlands
dcons(4) fixed by:	kan
2008-08-20 08:31:58 +00:00

148 lines
4.0 KiB
C

/*-
* Copyright (c) 1998 Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
* All rights reserved.
*
* This code is derived from software contributed to The DragonFly Project
* by Sascha Wildner <saw@online.de>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer as
* the first lines of this file unmodified.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_vga.h"
#ifndef VGA_NO_MODE_CHANGE
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/tty.h>
#include <sys/kernel.h>
#include <sys/fbio.h>
#include <sys/consio.h>
#include <machine/pc/vesa.h>
#include <dev/fb/fbreg.h>
#include <dev/syscons/syscons.h>
static tsw_ioctl_t *prev_user_ioctl;
static int
vesa_ioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
{
scr_stat *scp;
int mode;
scp = SC_STAT(tp);
switch (cmd) {
/* generic text modes */
case SW_TEXT_132x25: case SW_TEXT_132x30:
case SW_TEXT_132x43: case SW_TEXT_132x50:
case SW_TEXT_132x60:
if (!(scp->sc->adp->va_flags & V_ADP_MODECHANGE))
return ENODEV;
return sc_set_text_mode(scp, tp, cmd & 0xff, 0, 0, 0, 0);
/* text modes */
case SW_VESA_C80x60:
case SW_VESA_C132x25:
case SW_VESA_C132x43:
case SW_VESA_C132x50:
case SW_VESA_C132x60:
if (!(scp->sc->adp->va_flags & V_ADP_MODECHANGE))
return ENODEV;
mode = (cmd & 0xff) + M_VESA_BASE;
return sc_set_text_mode(scp, tp, mode, 0, 0, 0, 0);
/* graphics modes */
case SW_VESA_32K_320: case SW_VESA_64K_320:
case SW_VESA_FULL_320:
case SW_VESA_CG640x400:
case SW_VESA_CG640x480:
case SW_VESA_32K_640: case SW_VESA_64K_640:
case SW_VESA_FULL_640:
case SW_VESA_800x600: case SW_VESA_CG800x600:
case SW_VESA_32K_800: case SW_VESA_64K_800:
case SW_VESA_FULL_800:
case SW_VESA_1024x768: case SW_VESA_CG1024x768:
case SW_VESA_32K_1024: case SW_VESA_64K_1024:
case SW_VESA_FULL_1024:
case SW_VESA_1280x1024: case SW_VESA_CG1280x1024:
case SW_VESA_32K_1280: case SW_VESA_64K_1280:
case SW_VESA_FULL_1280:
if (!(scp->sc->adp->va_flags & V_ADP_MODECHANGE))
return ENODEV;
mode = (cmd & 0xff) + M_VESA_BASE;
return sc_set_graphics_mode(scp, tp, mode);
default:
if (IOCGROUP(cmd) == 'V') {
if (!(scp->sc->adp->va_flags & V_ADP_MODECHANGE))
return ENODEV;
mode = (cmd & 0xff) + M_VESA_BASE;
if (((cmd & IOC_DIRMASK) == IOC_VOID) &&
(mode > M_VESA_FULL_1280) &&
(mode < M_VESA_MODE_MAX))
return sc_set_graphics_mode(scp, tp, mode);
}
}
if (prev_user_ioctl)
return (*prev_user_ioctl)(tp, cmd, data, td);
else
return ENOIOCTL;
}
int
vesa_load_ioctl(void)
{
if (prev_user_ioctl)
return EBUSY;
prev_user_ioctl = sc_user_ioctl;
sc_user_ioctl = vesa_ioctl;
return 0;
}
int
vesa_unload_ioctl(void)
{
if (sc_user_ioctl != vesa_ioctl)
return EBUSY;
sc_user_ioctl = prev_user_ioctl;
prev_user_ioctl = NULL;
return 0;
}
#endif /* VGA_NO_MODE_CHANGE */