niansa-misc/linux
1
0
Fork 0
mirror of synced 2025-03-06 20:59:54 +01:00
Code Issues Projects Releases Packages Wiki Activity

iommu/amd: Add amd_iommu=force_enable option

Browse source 
Add this option to enable the IOMMU on platforms like AMD Stoney,
where the kernel usually disables it because it may cause problems in
some scenarios.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20210603130203.29016-1-joro@8bytes.org
This commit is contained in:
Joerg Roedel 2021-06-03 15:02:03 +02:00
parent 4b21a503ad
commit b1e650db2c
2 changed files with 11 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
Documentation/admin-guide/kernel-parameters.txt
View file

@ -301,6 +301,9 @@
allowed anymore to lift isolation allowed anymore to lift isolation
requirements as needed. This option requirements as needed. This option
does not override iommu=pt does not override iommu=pt
force_enable - Force enable the IOMMU on platforms known
to be buggy with IOMMU enabled. Use this
option with care.
amd_iommu_dump= [HW,X86-64] amd_iommu_dump= [HW,X86-64]
Enable AMD IOMMU driver option to dump the ACPI table Enable AMD IOMMU driver option to dump the ACPI table

9
drivers/iommu/amd/init.c
View file

@ -153,7 +153,8 @@ int amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_VAPIC;
static int amd_iommu_xt_mode = IRQ_REMAP_XAPIC_MODE; static int amd_iommu_xt_mode = IRQ_REMAP_XAPIC_MODE;
static bool amd_iommu_detected; static bool amd_iommu_detected;
static bool __initdata amd_iommu_disabled; static bool amd_iommu_disabled __initdata;
static bool amd_iommu_force_enable __initdata;
static int amd_iommu_target_ivhd_type; static int amd_iommu_target_ivhd_type;
u16 amd_iommu_last_bdf; /* largest PCI device id we have u16 amd_iommu_last_bdf; /* largest PCI device id we have
@ -2834,6 +2835,9 @@ static bool detect_ivrs(void)
acpi_put_table(ivrs_base); acpi_put_table(ivrs_base);
if (amd_iommu_force_enable)
goto out;
/* Don't use IOMMU if there is Stoney Ridge graphics */ /* Don't use IOMMU if there is Stoney Ridge graphics */
for (i = 0; i < 32; i++) { for (i = 0; i < 32; i++) {
u32 pci_id; u32 pci_id;
@ -2845,6 +2849,7 @@ static bool detect_ivrs(void)
} }
} }
out:
/* Make sure ACS will be enabled during PCI probe */ /* Make sure ACS will be enabled during PCI probe */
pci_request_acs(); pci_request_acs();
@ -3100,6 +3105,8 @@ static int __init parse_amd_iommu_options(char *str)
for (; *str; ++str) { for (; *str; ++str) {
if (strncmp(str, "fullflush", 9) == 0) if (strncmp(str, "fullflush", 9) == 0)
amd_iommu_unmap_flush = true; amd_iommu_unmap_flush = true;
if (strncmp(str, "force_enable", 12) == 0)
amd_iommu_force_enable = true;
if (strncmp(str, "off", 3) == 0) if (strncmp(str, "off", 3) == 0)
amd_iommu_disabled = true; amd_iommu_disabled = true;
if (strncmp(str, "force_isolation", 15) == 0) if (strncmp(str, "force_isolation", 15) == 0)