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Re: DMA buffer
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Re: DMA buffer

Michael Cashwell writes:
> It's because the G5's have 64-bit physical memory addresses but PCI
> only has 32. So even though wired memory cannot be paged out or moved

Not generally true. PCI has had 64-bit DAC ("Dual Address Cycle") for
many, manay years.

Other hardware provides an IOMMU mechanisme like the DART for PCI
cards which only speak 32-bit addresses, but Apple G5s have imposed
this 32-bit limit on all cards, no matter what their capabilities are.

Drew
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References: 
 >DMA buffer (From: "Lalit Chandivade" <email@hidden>)
 >Re: DMA buffer (From: Michael Cashwell <email@hidden>)



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