iommu/amd: Disable iommu only if amd_iommu=off is specified
It's ok to disable iommu early in normal kernel or in kdump kernel when
amd_iommu=off is specified. While we should not disable it in kdump kernel
when on-flight dma is still on-going.
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 88e7a6e..c7d0325 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -2499,7 +2499,8 @@
goto out;
/* Disable any previously enabled IOMMUs */
- disable_iommus();
+ if (!is_kdump_kernel() || amd_iommu_disabled)
+ disable_iommus();
if (amd_iommu_irq_remap)
amd_iommu_irq_remap = check_ioapic_information();