On Wed, Mar 12, 2014 at 12:41 PM, Linus Torvalds <torva...@linux-foundation.org> wrote: > On Wed, Mar 12, 2014 at 8:46 AM, Linus Torvalds > <torva...@linux-foundation.org> wrote: >> >> - do *not* add the HPET/VVAR page games to the legacy case. Get rid >> of the remap_pfn_pages() games entirely. > > .. actually, another approach would be to do the HPET/VVAR page games, > but make them non-legacy. > > The reason I hate seeing those remap_pfn_range() things is because > it's nasty code for a legacy case that I think shouldn't have new code > written for it, especially when it won't get testing by developers. > > So my reaction was "don't do that". > > But people pointing out that we can't do what x86-64 does made me > think: we could avoid the whole "nasty code for a legacy case" by > making it the *non*-legacy case. We could get rid of the fixmap > HPET/VVAR entirely - on x86-64 (which can use those addresses) a > PC-relative addressing is probably actually better anyway, so mapping > them together with the vdso code shouldn't hurt.
I think this is approximately what I was suggesting as a long-term solution :) > > Together with Andy's "remove legacy 32-bit fixmap vdso", I'd feel that > this is actually an _improvement_ to the current situation. > > Would something like that be more acceptable to everybody? I like it. This has the added benefit that the vvar symbols can be ordinary symbols as far as the compiler is concerned. Unfortunately, I don't know how to get the linker to play along without hardcoding the offsets of all the variables into the linker script. I'll play around a bit. --Andy It would be nice to get rid of the vvar declaration stuff, too > > Linus -- Andy Lutomirski AMA Capital Management, LLC -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
