alistair23-linux/drivers/gpu/drm/via/via_map.c
Dave Airlie 466e69b8b0 drm: move pci bus master enable into driver.
The current enabling of bus mastering in the drm midlayer allows a large
race condition under kexec. When a kexec'ed kernel re-enables bus mastering
for the GPU, previously setup dma blocks may cause writes to random pieces
of memory. On radeon the writeback mechanism can cause these sorts of issues.

This patch doesn't fix the problem, but it moves the bus master enable under
the individual drivers control so they can move enabling it until later in
their load cycle and close the race.

Fix for radeon kms driver will be in a follow-up patch.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-02-16 18:31:07 +00:00

131 lines
3.3 KiB
C

/*
* Copyright 1998-2003 VIA Technologies, Inc. All Rights Reserved.
* Copyright 2001-2003 S3 Graphics, Inc. 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, sub license,
* 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 NON-INFRINGEMENT. IN NO EVENT SHALL
* VIA, S3 GRAPHICS, 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.
*/
#include "drmP.h"
#include "via_drm.h"
#include "via_drv.h"
static int via_do_init_map(struct drm_device *dev, drm_via_init_t *init)
{
drm_via_private_t *dev_priv = dev->dev_private;
DRM_DEBUG("\n");
dev_priv->sarea = drm_getsarea(dev);
if (!dev_priv->sarea) {
DRM_ERROR("could not find sarea!\n");
dev->dev_private = (void *)dev_priv;
via_do_cleanup_map(dev);
return -EINVAL;
}
dev_priv->fb = drm_core_findmap(dev, init->fb_offset);
if (!dev_priv->fb) {
DRM_ERROR("could not find framebuffer!\n");
dev->dev_private = (void *)dev_priv;
via_do_cleanup_map(dev);
return -EINVAL;
}
dev_priv->mmio = drm_core_findmap(dev, init->mmio_offset);
if (!dev_priv->mmio) {
DRM_ERROR("could not find mmio region!\n");
dev->dev_private = (void *)dev_priv;
via_do_cleanup_map(dev);
return -EINVAL;
}
dev_priv->sarea_priv =
(drm_via_sarea_t *) ((u8 *) dev_priv->sarea->handle +
init->sarea_priv_offset);
dev_priv->agpAddr = init->agpAddr;
via_init_futex(dev_priv);
via_init_dmablit(dev);
dev->dev_private = (void *)dev_priv;
return 0;
}
int via_do_cleanup_map(struct drm_device *dev)
{
via_dma_cleanup(dev);
return 0;
}
int via_map_init(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
drm_via_init_t *init = data;
DRM_DEBUG("\n");
switch (init->func) {
case VIA_INIT_MAP:
return via_do_init_map(dev, init);
case VIA_CLEANUP_MAP:
return via_do_cleanup_map(dev);
}
return -EINVAL;
}
int via_driver_load(struct drm_device *dev, unsigned long chipset)
{
drm_via_private_t *dev_priv;
int ret = 0;
dev_priv = kzalloc(sizeof(drm_via_private_t), GFP_KERNEL);
if (dev_priv == NULL)
return -ENOMEM;
dev->dev_private = (void *)dev_priv;
dev_priv->chipset = chipset;
idr_init(&dev->object_name_idr);
pci_set_master(dev->pdev);
ret = drm_vblank_init(dev, 1);
if (ret) {
kfree(dev_priv);
return ret;
}
return 0;
}
int via_driver_unload(struct drm_device *dev)
{
drm_via_private_t *dev_priv = dev->dev_private;
idr_remove_all(&dev_priv->object_idr);
idr_destroy(&dev_priv->object_idr);
kfree(dev_priv);
return 0;
}