On Sun, May 03, 2020 at 06:09:01PM -0700, ira.weiny@xxxxxxxxx wrote: > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > The kmap infrastructure has been copied almost verbatim to every architecture. > This series consolidates obvious duplicated code by defining core functions > which call into the architectures only when needed. > > Some of the k[un]map_atomic() implementations have some similarities but the > similarities were not sufficient to warrant further changes. > > In addition we remove a duplicate implementation of kmap() in DRM. > > Testing was done by 0day to cover all the architectures I can't readily > build/test. OK... Looking through my old notes on kmap unification (this winter, never went anywhere), * arch/mips/mm/cache.c ought to use linux/highmem.h, not asm/highmem.h I suspect that your series doesn't build on some configs there. Hadn't verified that, though. * kmap_atomic_to_page() is dead, but not quite gone - csky and nds32 brought the damn thing back (nds32 - only an extern). It needs killin'... * parisc is (arguably) abusing kunmap()/kunmap_atomic() for cache flushing. Replace the bulk of its highmem.h with #define ARCH_HAS_FLUSH_ON_KUNMAP #define arch_before_kunmap flush_kernel_dcache_page_addr and have default kunmap()/kunmap_atomic() do #ifdef ARCH_HAS_FLUSH_ON_KUNMAP arch_before_kunmap(page_address(page)); #endif and #ifdef ARCH_HAS_FLUSH_ON_KUNMAP arch_before_kunmap(addr); #endif resp. Kills ARCH_HAS_KMAP along with ifdefs on it, makes parisc use somewhat less hacky. I'd suggest checking various configs on mips - that's likely to cause headache. Said that, my analysis of include chains back then is pretty much worthless by now - I really hate the amount of indirect include chains leading to that sucker on some, but not all configs ;-/ IIRC, the proof that everything using kmap*/kunmap* would pull linux/highmem.h regardless of config took several hours of digging, ran for several pages and had been hopelessly brittle. arch/mips/mm/cache.c was the only exception caught by it, but these days there might be more.
