On Wed, 2007-05-02 at 12:40 -0700, David Miller wrote: > From: "Michael Chan" <[EMAIL PROTECTED]> > Date: Wed, 2 May 2007 08:23:40 -0700 > > > A non-IOMMU system using 64-bit dma_addr_t will always set > > CONFIG_HIGHMEM, right? > > Nope, IA-64 is at least one example. > > IA-64 has both IOMMU and non-IOMMU configurations, and > never sets HIGHMEM. >
I see. So IA64 always uses the SWIOTLB when it doesn't have IOMMU then? I'm a bit confused. Is it enough to just set the DMA mask to 40-bit and forget about all this checking? I thought that wasn't enough. A tx packet can be anywhere in 64-bit memory. When it gets to the driver, pci_map will not do any translation even if DMA mask is set to 40-bit if it doesn't have IOMMU. Is that right? - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
