From a52357259680fe5368c2fabf5949209e231f2aa2 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 11 May 2010 17:12:33 +0200 Subject: [PATCH] x86/amd-iommu: Add amd_iommu=off command line option This patch adds a command line option to tell the AMD IOMMU driver to not initialize any IOMMU it finds. Signed-off-by: Joerg Roedel --- Documentation/kernel-parameters.txt | 2 ++ arch/x86/kernel/amd_iommu_init.c | 6 ++++++ 2 files changed, 8 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 839b21b0699a..0c6c56076d19 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -324,6 +324,8 @@ and is between 256 and 4096 characters. It is defined in the file they are unmapped. Otherwise they are flushed before they will be reused, which is a lot of faster + off - do not initialize any AMD IOMMU found in + the system amijoy.map= [HW,JOY] Amiga joystick support Map of devices attached to JOY0DAT and JOY1DAT diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index 6360abf993d4..3bacb4d0844c 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -120,6 +120,7 @@ struct ivmd_header { bool amd_iommu_dump; static int __initdata amd_iommu_detected; +static bool __initdata amd_iommu_disabled; u16 amd_iommu_last_bdf; /* largest PCI device id we have to handle */ @@ -1372,6 +1373,9 @@ void __init amd_iommu_detect(void) if (no_iommu || (iommu_detected && !gart_iommu_aperture)) return; + if (amd_iommu_disabled) + return; + if (acpi_table_parse("IVRS", early_amd_iommu_detect) == 0) { iommu_detected = 1; amd_iommu_detected = 1; @@ -1401,6 +1405,8 @@ static int __init parse_amd_iommu_options(char *str) for (; *str; ++str) { if (strncmp(str, "fullflush", 9) == 0) amd_iommu_unmap_flush = true; + if (strncmp(str, "off", 3) == 0) + amd_iommu_disabled = true; } return 1; -- 2.30.2