tree ab5cb3cb1768d5fafeb3021ad8ae1b6ae6d45017
parent 79872e35469b6db1c5243abded7b24367bd0a353
author Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com> 1414099175 -0200
committer Michael Ellerman <mpe@ellerman.id.au> 1421982166 +1100

powernv/iommu: disable IOMMU bypass with param iommu=nobypass

When IOMMU bypass is enabled, a PCI device can read and write memory
that was not mapped by the driver without causing an EEH. That might
cause memory corruption, for example.

When we disable bypass, DMA reads and writes to addresses not mapped by
the IOMMU will cause an EEH, allowing us to debug such issues.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>