From e51af6630848406fc97adbd71443818cdcda297b Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Thu, 4 Sep 2008 09:54:37 +0100 Subject: [PATCH] x86: blacklist DMAR on Intel G31/G33 chipsets Some BIOSes (the Intel DG33BU, for example) wrongly claim to have DMAR when they don't. Avoid the resulting crashes when it doesn't work as expected. I'd still be grateful if someone could test it on a DG33BU with the old BIOS though, since I've killed mine. I tested the DMI version, but not this one. Signed-off-by: David Woodhouse Signed-off-by: Ingo Molnar --- arch/x86/kernel/early-quirks.c | 18 ++++++++++++++++++ drivers/pci/intel-iommu.c | 2 +- include/asm-x86/iommu.h | 1 + 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index 4353cf5..24bb5fa 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -95,6 +95,20 @@ static void __init nvidia_bugs(int num, int slot, int func) } +#ifdef CONFIG_DMAR +static void __init intel_g33_dmar(int num, int slot, int func) +{ + struct acpi_table_header *dmar_tbl; + acpi_status status; + + status = acpi_get_table(ACPI_SIG_DMAR, 0, &dmar_tbl); + if (ACPI_SUCCESS(status)) { + printk(KERN_INFO "BIOS BUG: DMAR advertised on Intel G31/G33 chipset -- ignoring\n"); + dmar_disabled = 1; + } +} +#endif + #define QFLAG_APPLY_ONCE 0x1 #define QFLAG_APPLIED 0x2 #define QFLAG_DONE (QFLAG_APPLY_ONCE|QFLAG_APPLIED) @@ -114,6 +128,10 @@ static struct chipset early_qrk[] __initdata = { PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, via_bugs }, { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB, PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, fix_hypertransport_config }, +#ifdef CONFIG_DMAR + { PCI_VENDOR_ID_INTEL, 0x29c0, + PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, intel_g33_dmar }, +#endif {} }; diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 8d0e60a..eaba6ec 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -80,7 +80,7 @@ static long list_size; static void domain_remove_dev_info(struct dmar_domain *domain); -static int dmar_disabled; +int dmar_disabled; static int __initdata dmar_map_gfx = 1; static int dmar_forcedac; static int intel_iommu_strict; diff --git a/include/asm-x86/iommu.h b/include/asm-x86/iommu.h index 5f888cc..621a1af 100644 --- a/include/asm-x86/iommu.h +++ b/include/asm-x86/iommu.h @@ -6,6 +6,7 @@ extern void no_iommu_init(void); extern struct dma_mapping_ops nommu_dma_ops; extern int force_iommu, no_iommu; extern int iommu_detected; +extern int dmar_disabled; extern unsigned long iommu_num_pages(unsigned long addr, unsigned long len); -- 2.7.4