From ae7877de9cd8da075a46d5f615cb9fc9858e4b2f Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 26 Jun 2008 21:27:51 +0200 Subject: [PATCH] x86, AMD IOMMU: add early detection code This patch adds code to detect an AMD IOMMU early during boot before the early detection code of other IOMMUs run. Signed-off-by: Joerg Roedel Cc: iommu@lists.linux-foundation.org Cc: bhavna.sarathy@amd.com Cc: Sebastian.Biemueller@amd.com Cc: robert.richter@amd.com Cc: joro@8bytes.org Signed-off-by: Ingo Molnar --- arch/x86/kernel/amd_iommu_init.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index c792ddc4fec6..d7a75bf0f7e6 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -769,3 +769,23 @@ free: goto out; } +static int __init early_amd_iommu_detect(struct acpi_table_header *table) +{ + return 0; +} + +void __init amd_iommu_detect(void) +{ + if (swiotlb || no_iommu || iommu_detected) + return; + + if (amd_iommu_disable) + return; + + if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) { + iommu_detected = 1; + gart_iommu_aperture_disabled = 1; + gart_iommu_aperture = 0; + } +} +