From: Kevin Mitchell kevmitch@arista.com
[ Upstream commit 3ddbe913e55516d3e2165d43d4d5570761769878 ]
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: 2c0ae1720c09c ('iommu/amd: Convert iommu initialization to state machine') Signed-off-by: Kevin Mitchell kevmitch@arista.com Signed-off-by: Joerg Roedel jroedel@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iommu/amd_iommu_init.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c index 6a69b5bb231f..036fb186a3be 100644 --- a/drivers/iommu/amd_iommu_init.c +++ b/drivers/iommu/amd_iommu_init.c @@ -360,6 +360,9 @@ 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);