Subject: Re: x86-64 Re: IA64?
To: Jason R Thorpe <>
From: Matt Thomas <>
List: netbsd-users
Date: 01/01/2003 14:01:52
At 01:36 PM 1/1/2003, Jason R Thorpe wrote:
>On Wed, Jan 01, 2003 at 09:49:18PM +0100, Wojciech Puchar wrote:
>  > how about 32-bit PCI controllers on >=4GB memory?
>  >
>  > such powerfull system is likely to have 4GB of RAM or more.
>Bounce buffers.  Hooray.  (I would suspect that most high-performance
>systems that can support > 4GB RAM would also have PCI devices which
>can do 64-bit addressing...)

Except that even on alpha with 64bit PCI adapters that can address
 >4GB, we still use the SGMAP and map buffers < 4GB.  We really need
to fix this (whether it's having both 32bit and 64bit dmatags or
being able to pass a BUS_DMA_xxx flag indicating that no SGMAP
entries are needed.

Matt Thomas               Internet:
3am Software Foundry      WWW URL:
Cupertino, CA             Disclaimer: I avow all knowledge of this message