Commit d799a183 authored by Vasant Hegde's avatar Vasant Hegde Committed by Joerg Roedel
Browse files

iommu/amd: Add command-line option to enable different page table 



Enhance amd_iommu command line option to specify v1 or v2 page table.
By default system will boot in V1 page table mode.

Co-developed-by: default avatarSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: default avatarSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: default avatarVasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20220825063939.8360-10-vasant.hegde@amd.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 4db6c41f

Documentation/admin-guide/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -321,6 +321,8 @@ 
			force_enable - Force enable the IOMMU on platforms known

				       to be buggy with IOMMU enabled. Use this

				       option with care.

			pgtbl_v1     - Use v1 page table for DMA-API (Default).

			pgtbl_v2     - Use v2 page table for DMA-API.



	amd_iommu_dump=	[HW,X86-64]

			Enable AMD IOMMU driver option to dump the ACPI table

drivers/iommu/amd/init.c

+18 −5
Original line number Diff line number Diff line
@@ -3379,17 +3379,30 @@ static int __init parse_amd_iommu_intr(char *str) 


static int __init parse_amd_iommu_options(char *str)

{

	for (; *str; ++str) {

	if (!str)

		return -EINVAL;



	while (*str) {

		if (strncmp(str, "fullflush", 9) == 0) {

			pr_warn("amd_iommu=fullflush deprecated; use iommu.strict=1 instead\n");

			iommu_set_dma_strict();

		}

		if (strncmp(str, "force_enable", 12) == 0)

		} else if (strncmp(str, "force_enable", 12) == 0) {

			amd_iommu_force_enable = true;

		if (strncmp(str, "off", 3) == 0)

		} else if (strncmp(str, "off", 3) == 0) {

			amd_iommu_disabled = true;

		if (strncmp(str, "force_isolation", 15) == 0)

		} else if (strncmp(str, "force_isolation", 15) == 0) {

			amd_iommu_force_isolation = true;

		} else if (strncmp(str, "pgtbl_v1", 8) == 0) {

			amd_iommu_pgtable = AMD_IOMMU_V1;

		} else if (strncmp(str, "pgtbl_v2", 8) == 0) {

			amd_iommu_pgtable = AMD_IOMMU_V2;

		} else {

			pr_notice("Unknown option - '%s'\n", str);

		}



		str += strcspn(str, ",");

		while (*str == ',')

			str++;

	}



	return 1;