On Fri, Nov 30, 2007 at 04:14:55PM -0600, Kumar Gala wrote: > Ben and I are talking about using fixmap on ppc for similar applications to > it use on x86. However in poking around other arch's (sparc, mips) they > appear to have some support but not as complete as x86. > > For example both SPARC & MIPS reference __set_fixmap() in asm/fixmap.h but > I can't find an implementation on either. > > So I was wondering if there was some reason fixmap isn't as well supported > or if its just used for a specific function on those SPARC, MIPS, etc. and > they dont need as much functionality out of it as x86 does.
MIPS uses fixmap for two purposes: o In some cases it is possibly to avoid or optimize a cacheflush by creating a temporary mapping. The mechanism works very similar to what x86 and MIPS use for atomic kmaps. o Highmem. Both manipulate pagetables directly or even insert entries directly into the TLB without pagetables as intermediate stage so __set_fixmap is indeed unused. Ralf -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
