Re: alpha iommu fixes

[David S. Miller]

Alan Cox writes:
 > Pages allocated in main memory and mapped for access by PCI devices. On some
 > HP systems there is now way for such a page to stay coherent. It is quite
 > possible to sync the view but there is no sane way to allow any
 > pci_alloc_consistent to succeed

This is not what the HP folk told me, and in fact they said that
pci_alloc_consistent could be made to work via disabling the cache
attribute in the cpu side mappings or something similar in the PCI
controller IOMMU mappings.

Please someone on the HPPA team provide details :-)

Later,
David S. Miller
[e-mail]