Re: [patch] 32-bit dma memory zone

[Richard Henderson]

On Thu, Jun 07, 2001 at 02:22:10PM -0700, Linus Torvalds wrote:
> For example, what's the difference between ZONE_HIGHMEM and ZONE_NORMAL
> on a sane 64-bit architecture (right now I _think_ the 64-bit architectures
> actually make ZONE_NORMAL be what we call ZONE_DMA32 on x86, because they
> already need to be able to distinguish between memory that can be PCI-DMA'd
> to, and memory that needs bounce-buffers. Or maybe it's ZONE_DMA that they
> use for the DMA32 stuff?).

On most alphas we use only one zone -- ZONE_DMA.  The iommu makes it
possible to do 32-bit pci to the entire memory space.

For those alphas without an iommu, we also set up ZONE_NORMAL.

r~