On Tue, 2015-05-12 at 15:32 +0200, Christophe Leroy wrote: > cacheable_memzero uses dcbz instruction and is more efficient than > memset(0) when the destination is in RAM > > This patch renames memset as generic_memset, and defines memset > as a prolog to cacheable_memzero. This prolog checks if the byte > to set is 0 and if the buffer is in RAM. If not, it falls back to > generic_memcpy() > > Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> > --- > arch/powerpc/lib/copy_32.S | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S > index cbca76c..d8a9a86 100644 > --- a/arch/powerpc/lib/copy_32.S > +++ b/arch/powerpc/lib/copy_32.S > @@ -12,6 +12,7 @@ > #include <asm/cache.h> > #include <asm/errno.h> > #include <asm/ppc_asm.h> > +#include <asm/page.h> > > #define COPY_16_BYTES \ > lwz r7,4(r4); \ > @@ -74,6 +75,18 @@ CACHELINE_MASK = (L1_CACHE_BYTES-1) > * to set them to zero. This requires that the destination > * area is cacheable. -- paulus > */ > +_GLOBAL(memset) > + cmplwi r4,0 > + bne- generic_memset > + cmplwi r5,L1_CACHE_BYTES > + blt- generic_memset > + lis r8,max_pfn@ha > + lwz r8,max_pfn@l(r8) > + tophys (r9,r3) > + srwi r9,r9,PAGE_SHIFT > + cmplw r9,r8 > + bge- generic_memset > + mr r4,r5
max_pfn includes highmem, and tophys only works on normal kernel addresses. If we were to point memset_io, memcpy_toio, etc. at noncacheable versions, are there any other callers left that can reasonably point at uncacheable memory? -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
