Messages in this thread | | | Subject | Re: [PATCH v3] powerpc32: memcpy: only use dcbz once cache is enabled | From | Scott Wood <> | Date | Fri, 11 Sep 2015 16:35:15 -0500 |
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On Fri, 2015-09-11 at 16:33 +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, memcpy() > unconditionally jumps to generic_memcpy() which doesn't use > the dcbz instruction. > > Once the initial MMU is set up, in machine_init() we patch memcpy() > by replacing this inconditional jump by a NOP > > Reported-by: Michal Sojka <sojkam1@fel.cvut.cz> > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > changes in v2: > Using feature-fixups instead of hardcoded call to patch_instruction() > Handling of memset() added > changes in v3: > Not using anymore feature-fixups > Handling of memset() removed
Why was handling of memset() removed?
-Scott
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