linux-kernel - [PATCH 2/5]: drm: ati_pcigart: Need to use PCI_DMA

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Message-Id: <20090212.021534.233341037.davem@davemloft.net>
Date:	Thu, 12 Feb 2009 02:15:34 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	airlied@...ux.ie
CC:	benh@...nel.crashing.org, dri-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/5]: 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@...emloft.net>
---
 drivers/gpu/drm/ati_pcigart.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ati_pcigart.c b/drivers/gpu/drm/ati_pcigart.c
index 2cd827a..7972ec8 100644
--- 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);
-- 
1.6.1.2.350.g88cc

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