Re: [Intel IOMMU][patch 7/8] Support for legacy ISA devices

Andi Kleen
2007-04-24T19:33:22Z

On Tuesday 24 April 2007 08:03:06 Ashok Raj wrote:
> Floppy disk drivers dont work well with DMA remapping.

What is the problem? You can't allocate mappings <16MB?

> Its possible to
> extend the current use for x86_64, but the gain is very little. If someone
> feels compelled to clean this up, its up for grabs. Since these use 16M, we
> just provide a unity map for the ISA bridge device.
>

While it's probably not worth for the floppy there are other devices
with similar weird addressing limitations. Some generic handling of it
would be nice.

-Andi