Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754820Ab1C2XgI (ORCPT ); Tue, 29 Mar 2011 19:36:08 -0400 Received: from relay3.sgi.com ([192.48.152.1]:49718 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752112Ab1C2XgE (ORCPT ); Tue, 29 Mar 2011 19:36:04 -0400 Message-Id: <20110329233602.735667875@gulag1.americas.sgi.com> References: <20110329233602.272459647@gulag1.americas.sgi.com> User-Agent: quilt/0.46-1 Date: Tue, 29 Mar 2011 18:36:05 -0500 From: Mike Travis To: David Woodhouse , Jesse Barnes Cc: Mike Habeck , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] Intel pci: Limit dmar_init_reserved_ranges Content-Disposition: inline; filename=limit-dmar_init_reserved_ranges Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2020 Lines: 49 dmar_init_reserved_ranges() reserves the card's MMIO ranges to prevent handing out a DMA map that would overlap with the MMIO range. The problem while the Nvidia GPU has 64bit BARs, it's capable of receiving > 40bit PIOs, but can't generate > 40bit DMAs. So when the iommu code reserves these MMIO ranges a > 40bit entry ends up getting in the rbtree. On a UV test system with the Nvidia cards, the BARs are: 0001:36:00.0 VGA compatible controller: nVidia Corporation GT200GL Region 0: Memory at 92000000 (32-bit, non-prefetchable) [size=16M] Region 1: Memory at f8200000000 (64-bit, prefetchable) [size=256M] Region 3: Memory at 90000000 (64-bit, non-prefetchable) [size=32M] So this 44bit MMIO address 0xf8200000000 ends up in the rbtree. As DMA maps get added and deleted from the rbtree we can end up getting a cached entry to this 0xf8200000000 entry... this is what results in the code handing out the invalid DMA map of 0xf81fffff000: [ 0xf8200000000-1 >> PAGE_SIZE << PAGE_SIZE ] The IOVA code needs to better honor the "limit_pfn" when allocating these maps. Signed-off-by: Mike Travis Reviewed-by: Mike Habeck --- drivers/pci/intel-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- linux.orig/drivers/pci/intel-iommu.c +++ linux/drivers/pci/intel-iommu.c @@ -1323,7 +1323,8 @@ static void dmar_init_reserved_ranges(vo for (i = 0; i < PCI_NUM_RESOURCES; i++) { r = &pdev->resource[i]; - if (!r->flags || !(r->flags & IORESOURCE_MEM)) + if (!r->flags || !(r->flags & IORESOURCE_MEM) || + r->start > pdev->dma_mask) continue; iova = reserve_iova(&reserved_iova_list, IOVA_PFN(r->start), -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/