From 62edf5dc4a524e4cb525e6020b955a1ad593d9ba Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sat, 4 Jul 2009 10:59:46 +0100 Subject: [PATCH] intel-iommu: Restore DMAR_BROKEN_GFX_WA option for broken graphics drivers We need to give people a little more time to fix the broken drivers. Re-introduce this, but tied in properly with the 'iommu=pt' support this time. Change the config option name and make it default to 'no' too. Signed-off-by: David Woodhouse --- arch/x86/Kconfig | 12 ++++++++++++ drivers/pci/intel-iommu.c | 29 +++++++++++++++++++---------- 2 files changed, 31 insertions(+), 10 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index c07f72205909..738bdc6b0f8b 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1913,6 +1913,18 @@ config DMAR_DEFAULT_ON recommended you say N here while the DMAR code remains experimental. +config DMAR_BROKEN_GFX_WA + def_bool n + prompt "Workaround broken graphics drivers (going away soon)" + depends on DMAR + ---help--- + Current Graphics drivers tend to use physical address + for DMA and avoid using DMA APIs. Setting this config + option permits the IOMMU driver to set a unity map for + all the OS-visible memory. Hence the driver can continue + to use physical addresses for DMA, at least until this + option is removed in the 2.6.32 kernel. + config DMAR_FLOPPY_WA def_bool y depends on DMAR diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index ae5ccdf8b19f..5ee8305257ea 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -2127,16 +2127,18 @@ static int iommu_prepare_static_identity_mapping(void) return -EFAULT; for_each_pci_dev(pdev) { - printk(KERN_INFO "IOMMU: identity mapping for device %s\n", - pci_name(pdev)); + if (iommu_identity_mapping == 1 || IS_GFX_DEVICE(pdev)) { + printk(KERN_INFO "IOMMU: identity mapping for device %s\n", + pci_name(pdev)); - ret = domain_context_mapping(si_domain, pdev, - CONTEXT_TT_MULTI_LEVEL); - if (ret) - return ret; - ret = domain_add_dev_info(si_domain, pdev); - if (ret) - return ret; + ret = domain_context_mapping(si_domain, pdev, + CONTEXT_TT_MULTI_LEVEL); + if (ret) + return ret; + ret = domain_add_dev_info(si_domain, pdev); + if (ret) + return ret; + } } return 0; @@ -2291,6 +2293,10 @@ int __init init_dmars(void) * identity mapping if iommu_identity_mapping is set. */ if (!iommu_pass_through) { +#ifdef CONFIG_DMAR_BROKEN_GFX_WA + if (!iommu_identity_mapping) + iommu_identity_mapping = 2; +#endif if (iommu_identity_mapping) iommu_prepare_static_identity_mapping(); /* @@ -2444,7 +2450,10 @@ static int iommu_dummy(struct pci_dev *pdev) static int iommu_should_identity_map(struct pci_dev *pdev) { - return pdev->dma_mask > DMA_BIT_MASK(32); + if (iommu_identity_mapping == 2) + return IS_GFX_DEVICE(pdev); + else + return pdev->dma_mask > DMA_BIT_MASK(32); } /* Check if the pdev needs to go through non-identity map and unmap process.*/ -- 2.39.5