Re: (reposting) how to get DMA'able memory within 4GB on 64-bit m achi ne

From: David S. Miller (
Date: Thu Jun 28 2001 - 17:01:27 EST

Jes Sorensen writes:
> >>>>> "Hiren" == MEHTA,HIREN (A-SanJose,ex1) <> writes:
> Hiren> Then why do we have 64-bit dma_addr_t on ia64 ? -hiren
> Because on ia64 you will get back a 64 bit pointer if you use
> pci_set_dma_mask() to set a 64 bit mask before calling the pci
> functions in question.

Please note that this is nonstandard and undocumented behavior.

This is not a supported API at all, and the way 64-bit DMA will
eventually be done across all platforms is likely to be different.

David S. Miller
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This archive was generated by hypermail 2b29 : Sat Jun 30 2001 - 21:00:20 EST