Messages in this thread | | | Date | 20 Apr 2004 20:51:12 +0200 | Date | Tue, 20 Apr 2004 20:51:12 +0200 | From | Andi Kleen <> | Subject | Re: PAT support |
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On Mon, Apr 19, 2004 at 05:54:57PM -0500, Terence Ripperda wrote: > > I think I prefer the do/undo model instead of push/pop. > > That can work with cmaps too. PAGE_KERNEL means no cmap, > > PAGE_KERNEL_WC and PAGE_KERNEL_NOCACHE get a cmap. > > but then what is the point of cmap? I would expect a mix of WC and UC mappings to be much less dangerous than a mix of WC/UC and WB. perhaps my mindset is wrong, but it seems allowing ioremap to request a cached mapping is important, and that if that mapping was followed by ioremap_nocached or ioremap_wrcomb, that these subsequent calls should fail.
Hmm, you're right. push/pop is probably better for io-mappings, otherwise we cannot catch existing mappings. This will be needed for user mmap too.
Ignore my previous suggestion on that then please. Sorry for the noise.
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