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>

drivers/gpu/drm/drm_pci.c

@@ -324,8 +324,6 @@ int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
 	if (ret)
 		goto err_g1;
 
-	pci_set_master(pdev);
-
 	dev->pdev = pdev;
 	dev->dev = &pdev->dev;
 

drivers/gpu/drm/gma500/psb_drv.c

@@ -283,6 +283,8 @@ static int psb_driver_load(struct drm_device *dev, unsigned long chipset)
 	dev_priv->dev = dev;
 	dev->dev_private = (void *) dev_priv;
 
+	pci_set_master(dev->pdev);
+
 	if (!IS_PSB(dev)) {
 		if (pci_enable_msi(dev->pdev))
 			dev_warn(dev->dev, "Enabling MSI failed!\n");

drivers/gpu/drm/i810/i810_dma.c

@@ -1208,6 +1208,8 @@ int i810_driver_load(struct drm_device *dev, unsigned long flags)
 	dev->types[8] = _DRM_STAT_SECONDARY;
 	dev->types[9] = _DRM_STAT_DMA;
 
+	pci_set_master(dev->pdev);
+
 	return 0;
 }
 

drivers/gpu/drm/i915/i915_dma.c

@@ -1933,6 +1933,8 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 		goto free_priv;
 	}
 
+	pci_set_master(dev->pdev);
+
 	/* overlay on gen2 is broken and can't address above 1G */
 	if (IS_GEN2(dev))
 		dma_set_coherent_mask(&dev->pdev->dev, DMA_BIT_MASK(30));

drivers/gpu/drm/mga/mga_dma.c

@@ -403,6 +403,8 @@ int mga_driver_load(struct drm_device *dev, unsigned long flags)
 	dev_priv->usec_timeout = MGA_DEFAULT_USEC_TIMEOUT;
 	dev_priv->chipset = flags;
 
+	pci_set_master(dev->pdev);
+
 	dev_priv->mmio_base = pci_resource_start(dev->pdev, 1);
 	dev_priv->mmio_size = pci_resource_len(dev->pdev, 1);
 

drivers/gpu/drm/nouveau/nouveau_state.c

@@ -1002,6 +1002,8 @@ int nouveau_load(struct drm_device *dev, unsigned long flags)
 	dev->dev_private = dev_priv;
 	dev_priv->dev = dev;
 
+	pci_set_master(dev->pdev);
+
 	dev_priv->flags = flags & NOUVEAU_FLAGS;
 
 	NV_DEBUG(dev, "vendor: 0x%X device: 0x%X class: 0x%X\n",

drivers/gpu/drm/r128/r128_drv.c

@@ -85,6 +85,7 @@ static struct drm_driver driver = {
 
 int r128_driver_load(struct drm_device *dev, unsigned long flags)
 {
+	pci_set_master(dev->pdev);
 	return drm_vblank_init(dev, 1);
 }
 

drivers/gpu/drm/radeon/radeon_cp.c

@@ -2115,6 +2115,8 @@ int radeon_driver_load(struct drm_device *dev, unsigned long flags)
 		break;
 	}
 
+	pci_set_master(dev->pdev);
+
 	if (drm_pci_device_is_agp(dev))
 		dev_priv->flags |= RADEON_IS_AGP;
 	else if (pci_is_pcie(dev->pdev))

drivers/gpu/drm/radeon/radeon_kms.c

@@ -57,6 +57,8 @@ int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
 	}
 	dev->dev_private = (void *)rdev;
 
+	pci_set_master(dev->pdev);
+
 	/* update BUS flag */
 	if (drm_pci_device_is_agp(dev)) {
 		flags |= RADEON_IS_AGP;

drivers/gpu/drm/sis/sis_drv.c

@@ -41,6 +41,8 @@ static int sis_driver_load(struct drm_device *dev, unsigned long chipset)
 {
 	drm_sis_private_t *dev_priv;
 
+	pci_set_master(dev->pdev);
+
 	dev_priv = kzalloc(sizeof(drm_sis_private_t), GFP_KERNEL);
 	if (dev_priv == NULL)
 		return -ENOMEM;

drivers/gpu/drm/via/via_map.c

@@ -106,6 +106,8 @@ int via_driver_load(struct drm_device *dev, unsigned long chipset)
 
 	idr_init(&dev->object_name_idr);
 
+	pci_set_master(dev->pdev);
+
 	ret = drm_vblank_init(dev, 1);
 	if (ret) {
 		kfree(dev_priv);

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -439,6 +439,8 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
 	}
 	memset(dev_priv, 0, sizeof(*dev_priv));
 
+	pci_set_master(dev->pdev);
+
 	dev_priv->dev = dev;
 	dev_priv->vmw_chipset = chipset;
 	dev_priv->last_read_seqno = (uint32_t) -100;