Messages in this thread | | | Date | Fri, 06 Jul 2001 11:39:57 -0400 | From | Jeff Garzik <> | Subject | Re: DMA memory limitation? |
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Steffen Persvold wrote: > > pci_alloc_* is designed to support ISA. > > > > Pass pci_dev==NULL to pci_alloc_* for ISA devices, and it allocs GFP_DMA > > for you.
> Sure, but the IA64 platforms that are out now doesn't have an IOMMU, so bounce buffers are > used if you don't specify GFP_DMA in your get_free_page. [...] > (pci_alloc_consistent() allocates a buffer with GFP_DMA on IA64),
The important thing is that pci_alloc_consistent and the other PCI DMA functions work as advertised on IA64. If you pass NULL to pci_alloc_consistent, IA64 should give you an ISA DMA-able address. If you don't, you get a 32-bit PCI DMA address. Use of GFP_DMA is a arch-specific detail, so don't let me confuse you there.
-- Jeff Garzik | A recent study has shown that too much soup Building 1024 | can cause malaise in laboratory mice. MandrakeSoft | - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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