Messages in this thread | | | Date | Fri, 15 May 1998 14:17:29 -0700 | From | "David S. Miller" <> | Subject | Re: DMA from/to user-space memory |
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From: Benny Amorsen <amorsen@sscnet.com> Date: 15 May 1998 23:16:43 +0200
>>>>> "DSM" == David S Miller <davem@dm.cobaltmicro.com> writes:
DSM> I also agree with Robert that making part of the DMA interface DSM> cater to ISA 16MB limitations is likely to be totally unused by DSM> anyone. (I'm happy to be shown wrong, if you can think of a DSM> useful and legitimate counterexample, speak up ;-)
How about catering to PCI 4GB limitations on 64 bit architectures?
On the 64-bit architectures I know of, and PCI as specified, is not limited to 64-bits of physical addressing.
But back to reality, yes most cards don't implement dual address cycles at all. We could have the interface use GFP_DMA, which on sparc64 for example gets you a page in the lower 32-bits of physical address space.
Later, David S. Miller davem@dm.cobaltmicro.com
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