[Linux-ia64] Re: 64 Bits DMA Addresses for Alloc Consistent Interfaces.

Colin Ngam
2003-05-15T23:32:31Z

"David S. Miller" wrote:

> From: Colin Ngam <cngam@sgi.com>
> Date: Thu, 15 May 2003 17:14:11 -0500
>
> Now, for PCI-X devices, we need to generate an IOMMU mapped DMA
> address that has the Upper 32 bits non 0s.
>
> Then add a consistent_dma_mask attribute to the device struct,
> problem solved.

Hi David,

I do not understand what you are saying .. how would a consistent_dma_mask
attribute in the device struct helps pci_alloc_consistent() to return a dma
hanlde
that can have the Upper 32 Bits Non 0's, and, moreover, these Upper 32 Bits
are not constants, but can vary greatly, and is part of the 64 bit Physical
System
Memory Address?

Thanks.

colin