[PATCH v9 13/13] iommu/amd: Disable iommu only if amd_iommu=off is specified

Baoquan He
2017-08-01T11:38:52Z

It's ok to disable iommu in normal kernel. While there's no need
to disable it in kdump kernel after the on-flight dma issue has
heen fixed.

Signed-off-by: Baoquan He <bhe@redhat.com>
---
drivers/iommu/amd_iommu_init.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index cada2e302761..5015d61c1dcf 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2502,7 +2502,8 @@ static int __init early_amd_iommu_init(void)
goto out;

/* Disable any previously enabled IOMMUs */
- disable_iommus();
+ if (amd_iommu_disabled)
+ disable_iommus();

if (amd_iommu_irq_remap)
amd_iommu_irq_remap = check_ioapic_information();
--
2.5.5