Messages in this thread | | | Subject | Re: can device drivers return non-ram via vm_ops->nopage? | From | Benjamin Herrenschmidt <> | Date | Mon, 22 Mar 2004 15:57:29 +1100 |
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> exists because architectures haven't defined their private > pgprot_writecombine() implementations, preferring instead to add > to the preprocessor junk instead.
And it's not even about writecombine... Like writecombine is an attribute of the PCI host bridge on pmacs, not a pgprot, while cacheability issues cannot be always abstracted the same way on different archs. Actually, GUARDED could be used for !writecombine on ppc, but !GUARDED would allow prefetch and out of order IOs....
Ben.
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