drm: ati_pcigart: Need to use PCI_DMA_BIDIRECTIONAL.

The buffers mapped by the PCI GART can be written to by the device,
not just read.

For example, this happens via the RB_RPTR writeback on Radeon.

So we can't use PCI_DMA_TODEVICE else we'll get protection faults
on IOMMU platforms.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dave Airlie <airlied@linux.ie>

diff --git a/drivers/gpu/drm/ati_pcigart.c b/drivers/gpu/drm/ati_pcigart.c
index 2cd827a..7972ec8 100644 (file)
--- a/drivers/gpu/drm/ati_pcigart.c
+++ b/drivers/gpu/drm/ati_pcigart.c
@@ -77,7 +77,7 @@ int drm_ati_pcigart_cleanup(struct drm_device *dev, struct drm_ati_pcigart_info
                        if (!entry->busaddr[i])
                                break;
                        pci_unmap_page(dev->pdev, entry->busaddr[i],
-                                        PAGE_SIZE, PCI_DMA_TODEVICE);
+                                        PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
                }
 
                if (gart_info->gart_table_location == DRM_ATI_GART_MAIN)
@@ -145,7 +145,7 @@ int drm_ati_pcigart_init(struct drm_device *dev, struct drm_ati_pcigart_info *ga
        for (i = 0; i < pages; i++) {
                /* we need to support large memory configurations */
                entry->busaddr[i] = pci_map_page(dev->pdev, entry->pagelist[i],
-                                                0, PAGE_SIZE, PCI_DMA_TODEVICE);
+                                                0, PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
                if (entry->busaddr[i] == 0) {
                        DRM_ERROR("unable to map PCIGART pages!\n");
                        drm_ati_pcigart_cleanup(dev, gart_info);