On Wed, Jun 17, 2009 at 12:58, Marco wrote: > Jared Hulbert wrote: >> > > +#if defined(CONFIG_ARM) || defined(CONFIG_M68K) || defined(CONFIG_H8300) || \ >> > > + ? ? ? defined(CONFIG_BLACKFIN) >> > > + ? ? ? /* >> > > + ? ? ? ?* FIXME: so far only these archs have flush_tlb_kernel_page(), >> > > + ? ? ? ?* for the rest just use flush_tlb_kernel_range(). Not ideal >> > > + ? ? ? ?* to use _range() because many archs just flush the whole TLB. >> > > + ? ? ? ?*/ >> > > + ? ? ? if (end <= start + PAGE_SIZE) >> > > + ? ? ? ? ? ? ? flush_tlb_kernel_page(start); >> > > + ? ? ? else >> > > +#endif >> > > + ? ? ? ? ? ? ? flush_tlb_kernel_range(start, end); >> > > +} >> > >> > Why not just fix flush_tlb_range()? >> > >> > If an arch has a flush_tlb_kernel_page() that works then it stands to >> > reason that the flush_tlb_kernel_range() shouldn't work with minimal >> > effort, no? >> >> flush_tlb_kernel_page() is a new one to me, it doesn't have any mention >> in Documentation/cachetlb.txt anyways. >> >> Many of the flush_tlb_kernel_range() implementations do ranged checks >> with tunables to determine whether it is more expensive to selectively >> flush vs just blowing the entire TLB away. >> >> Likewise, there is no reason why those 4 architectures can not just shove >> that if (end <= start + PAGE_SIZE) check in the beginning of their >> flush_tlb_kernel_range() and fall back on flush_tlb_kernel_page() for >> those cases. Hiding this in generic code is definitely not the way to go. > > Ok I'll change that function at arch level and I'll remove the ifdef, I'll call only flush_tlb_kernel_page(), but I'd like to know what is the opinion of the arch maintainers to do that. considering Blackfin defines flush_tlb_kernel_page() to BUG(), i dont think we care what happens. we dont have a MMU, so all tlb funcs -> BUG(). presumably this code shouldnt have been compiled in the first place for us. -mike -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
