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27 March 2024, 02:37:15 UTC
Revision 1cd03890ea64795e53f17a94928cca22495acb2a authored by LEROY Christophe on 16 September 2015, 10:04:51 UTC, committed by Michael Ellerman on 17 September 2015, 00:36:44 UTC 
powerpc32: memcpy: only use dcbz once cache is enabled
 
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>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
1 parent 36b35d5
History
Tip revision: 1cd03890ea64795e53f17a94928cca22495acb2a authored by LEROY Christophe on 16 September 2015, 10:04:51 UTC
powerpc32: memcpy: only use dcbz once cache is enabled
Tip revision: 1cd0389
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