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linux/drivers/gpu/drm/nouveau/nouveau_ioc32.c
Arnd Bergmann ed8b670409 drm: convert drm_ioctl to unlocked_ioctl
drm_ioctl is called with the Big Kernel Lock held,
which shows up very high in statistics on vfs_ioctl.

Moving the lock into the drm_ioctl function itself
makes sure we blame the right subsystem and it gets
us one step closer to eliminating the locked version
of fops->ioctl.

Since drm_ioctl does not require the lock itself,
we only need to hold it while calling the specific
handler. The 32 bit conversion handlers do not
interact with any other code, so they don't need
the BKL here either and can just call drm_ioctl.

As a bonus, this cleans up all the other users
of drm_ioctl which now no longer have to find
the inode or call lock_kernel.

[airlied: squashed the non-driver bits
of the second patch in here, this provides
the flag for drivers to use to select unlocked
ioctls - but doesn't modify any drivers].

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.sourceforge.net
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2009-12-18 11:22:31 +10:00

71 lines
2.2 KiB
C

/**
* \file mga_ioc32.c
*
* 32-bit ioctl compatibility routines for the MGA DRM.
*
* \author Dave Airlie <airlied@linux.ie> with code from patches by Egbert Eich
*
*
* Copyright (C) Paul Mackerras 2005
* Copyright (C) Egbert Eich 2003,2004
* Copyright (C) Dave Airlie 2005
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <linux/compat.h>
#include "drmP.h"
#include "drm.h"
#include "nouveau_drv.h"
/**
* Called whenever a 32-bit process running under a 64-bit kernel
* performs an ioctl on /dev/dri/card<n>.
*
* \param filp file pointer.
* \param cmd command.
* \param arg user argument.
* \return zero on success or negative number on failure.
*/
long nouveau_compat_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
unsigned int nr = DRM_IOCTL_NR(cmd);
drm_ioctl_compat_t *fn = NULL;
int ret;
if (nr < DRM_COMMAND_BASE)
return drm_compat_ioctl(filp, cmd, arg);
#if 0
if (nr < DRM_COMMAND_BASE + DRM_ARRAY_SIZE(mga_compat_ioctls))
fn = nouveau_compat_ioctls[nr - DRM_COMMAND_BASE];
#endif
if (fn != NULL)
ret = (*fn)(filp, cmd, arg);
else
ret = drm_ioctl(filp, cmd, arg);
return ret;
}