On Mon, 2015-09-07 at 16:24 +0200, Christophe Leroy wrote: > memcpy() uses instruction dcbz to speed up copy by not wasting time > loading cache line with data that will be overwritten. > Some platform like mpc52xx do no have cache active at startup and > can therefore not use memcpy(). Allthough no part of the code > explicitly uses memcpy(), GCC makes calls to it. > > This patch modifies memcpy() such that at startup, the 'dcbz' > instruction is replaced by 'dcbt' which is harmless if cache is not > enabled, and which helps a bit (allthough not as much as dcbz) if > cache is already enabled. > > Once the initial MMU is setup, in machine_init() we patch memcpy() > by replacing the temporary 'dcbt' by 'dcbz' > > Reported-by: Michal Sojka <sojk...@fel.cvut.cz> > Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
Is there some reason you can't use the normal cpu feature sections? See arch/powerpc/lib/memcpy_64.S for an example of what I mean. cheers -- 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/
