[PATCH 1/1] x86/iommu: fix incorrect bit operations in setting values

[Li, ZhenHua]

> 1st step shows we should NOT disable the iommu when it is already
> enabled. But current code does disable-enable. So there is still works
> to do.
>

The original kernel does a disable and re-enable , Bill's patchset 
removed the disable operation.

> I think step 2 is necessary, because when the driver initializes, the
> device need a new map, and the old data from the old kernel can not be
> used for the new driver.
>
> Now I am trying to implement these ideas.
>
>> Thanks