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Commit a5235725 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

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: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent b57f95a3

Documentation/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kernel/amd_iommu_init.c

+6 −0
Original line number Diff line number Diff line
@@ -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;