linux/drivers/gpu/drm/i830/i830_drv.c
Arnd Bergmann 58374713c9 drm: kill BKL from common code
This restricts the use of the big kernel lock to the i830 and i810
device drivers. The three remaining users in common code (open, ioctl
and release) get converted to a new mutex, the drm_global_mutex,
making the locking stricter than the big kernel lock.

This may have a performance impact, but only in those cases that
currently don't use DRM_UNLOCKED flag in the ioctl list and would
benefit from that anyway.

The reason why i810 and i830 cannot use drm_global_mutex in their
mmap functions is a lock-order inversion problem between the current
use of the BKL and mmap_sem in these drivers. Since the BKL has
release-on-sleep semantics, it's harmless but it would cause trouble
if we replace the BKL with a mutex.

Instead, these drivers get their own ioctl wrappers that take the
BKL around every ioctl call and then set their own handlers as
DRM_UNLOCKED.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-08-05 11:54:40 +10:00

109 lines
3.3 KiB
C

/* i830_drv.c -- I810 driver -*- linux-c -*-
* Created: Mon Dec 13 01:56:22 1999 by jhartmann@precisioninsight.com
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* 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
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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.
*
* Authors:
* Rickard E. (Rik) Faith <faith@valinux.com>
* Jeff Hartmann <jhartmann@valinux.com>
* Gareth Hughes <gareth@valinux.com>
* Abraham vd Merwe <abraham@2d3d.co.za>
* Keith Whitwell <keith@tungstengraphics.com>
*/
#include "drmP.h"
#include "drm.h"
#include "i830_drm.h"
#include "i830_drv.h"
#include "drm_pciids.h"
static struct pci_device_id pciidlist[] = {
i830_PCI_IDS
};
static struct drm_driver driver = {
.driver_features =
DRIVER_USE_AGP | DRIVER_REQUIRE_AGP | DRIVER_USE_MTRR |
DRIVER_HAVE_DMA | DRIVER_DMA_QUEUE,
#if USE_IRQS
.driver_features |= DRIVER_HAVE_IRQ | DRIVER_SHARED_IRQ,
#endif
.dev_priv_size = sizeof(drm_i830_buf_priv_t),
.load = i830_driver_load,
.lastclose = i830_driver_lastclose,
.preclose = i830_driver_preclose,
.device_is_agp = i830_driver_device_is_agp,
.reclaim_buffers_locked = i830_driver_reclaim_buffers_locked,
.dma_quiescent = i830_driver_dma_quiescent,
.get_map_ofs = drm_core_get_map_ofs,
.get_reg_ofs = drm_core_get_reg_ofs,
#if USE_IRQS
.irq_preinstall = i830_driver_irq_preinstall,
.irq_postinstall = i830_driver_irq_postinstall,
.irq_uninstall = i830_driver_irq_uninstall,
.irq_handler = i830_driver_irq_handler,
#endif
.ioctls = i830_ioctls,
.fops = {
.owner = THIS_MODULE,
.open = drm_open,
.release = drm_release,
.unlocked_ioctl = i830_ioctl,
.mmap = drm_mmap,
.poll = drm_poll,
.fasync = drm_fasync,
},
.pci_driver = {
.name = DRIVER_NAME,
.id_table = pciidlist,
},
.name = DRIVER_NAME,
.desc = DRIVER_DESC,
.date = DRIVER_DATE,
.major = DRIVER_MAJOR,
.minor = DRIVER_MINOR,
.patchlevel = DRIVER_PATCHLEVEL,
};
static int __init i830_init(void)
{
driver.num_ioctls = i830_max_ioctl;
return drm_init(&driver);
}
static void __exit i830_exit(void)
{
drm_exit(&driver);
}
module_init(i830_init);
module_exit(i830_exit);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL and additional rights");