[parisc-linux] ZONE_DMA

[Grant Grundler]

Alan Cox wrote:
> Some Alpha's probably can but we don't support that. The pci side API
> pci_alloc_consistent does

Nit: I think pci_dma_supported() is the interface meant here.

Documentation/DMA-mapping.txt has a good example here on how
pci_dma_supported() supports cripppled PCI devices.

Right now, SBA code (and CCIO too I think) only permit devices
that say they support 32-bit addressing. sba_dma_supported()
code needs to be revisited for two reasons:
o the number of bits the IO MMU actually uses is typically alot less
  - depends on the size of the I/O Pdir. Ie it could support the
  crippled PCI device pretty easily.
o Elroy HW supports 64-bit PCI addressing (Dual Address cycle).

grant

Grant Grundler
Unix Systems Enablement Lab
+1.408.447.7253