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Commit cbda1ba8 authored by David Woodhouse's avatar David Woodhouse Committed by Jesse Barnes
Browse files

PCI/iommu: 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.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 1941246d

drivers/pci/intel-iommu.c

+23 −0
Original line number Diff line number Diff line
@@ -2348,11 +2348,34 @@ static void __init iommu_exit_mempool(void) 


}



static int blacklist_iommu(const struct dmi_system_id *id)

{

	printk(KERN_INFO "%s detected; disabling IOMMU\n",

	       id->ident);

	dmar_disabled = 1;

	return 0;

}



static struct dmi_system_id __initdata intel_iommu_dmi_table[] = {

	{	/* Some DG33BU BIOS revisions advertised non-existent VT-d */

		.callback = blacklist_iommu,

		.ident = "Intel DG33BU",

		{	DMI_MATCH(DMI_BOARD_VENDOR, "Intel Corporation"),

			DMI_MATCH(DMI_BOARD_NAME, "DG33BU"),

		}

	},

	{ }

};





void __init detect_intel_iommu(void)

{

	if (swiotlb || no_iommu || iommu_detected || dmar_disabled)

		return;

	if (early_dmar_detect()) {

		dmi_check_system(intel_iommu_dmi_table);

		if (dmar_disabled)

			return;

		iommu_detected = 1;

	}

}