iommu/amd: Make iommu_disable safer

Make it safe to call iommu_disable during early init error conditions
before mmio_base is set, but after the struct amd_iommu has been added
to the amd_iommu_list. For example, this happens if firmware fails to
fill in mmio_phys in the ACPI table leading to a NULL pointer
dereference in iommu_feature_disable.

Fixes: 2c0ae1720c ('iommu/amd: Convert iommu initialization to state machine')
Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Kevin Mitchell 2019-06-12 14:52:03 -07:00 committed by Joerg Roedel
parent c1ddcf1cc9
commit 3ddbe913e5

View file

@ -418,6 +418,9 @@ static void iommu_enable(struct amd_iommu *iommu)
static void iommu_disable(struct amd_iommu *iommu)
{
if (!iommu->mmio_base)
return;
/* Disable command buffer */
iommu_feature_disable(iommu, CONTROL_CMDBUF_EN);