From ad1b0122bdc96cbcfcfbc9ef59f9bf3658802a72 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Wed, 23 Aug 2017 16:54:38 +0200 Subject: powerpc/32: remove a NOP from memset() memset() is patched after initialisation to activate the optimised part which uses cache instructions. Today we have a 'b 2f' to skip the optimised patch, which then gets replaced by a NOP, implying a useless cycle consumption. As we have a 'bne 2f' just before, we could use that instruction for the live patching, hence removing the need to have a dedicated 'b 2f' to be replaced by a NOP. This patch changes the 'bne 2f' by a 'b 2f'. During init, that 'b 2f' is then replaced by 'bne 2f' Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman --- arch/powerpc/lib/copy_32.S | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch/powerpc/lib/copy_32.S') diff --git a/arch/powerpc/lib/copy_32.S b/arch/powerpc/lib/copy_32.S index 05aaee20590f..da425bb6b369 100644 --- a/arch/powerpc/lib/copy_32.S +++ b/arch/powerpc/lib/copy_32.S @@ -103,9 +103,12 @@ _GLOBAL(memset) add r5,r0,r5 subf r6,r0,r3 cmplwi 0,r4,0 - bne 2f /* Use normal procedure if r4 is not zero */ + /* + * Skip optimised bloc until cache is enabled. Will be replaced + * by 'bne' during boot to use normal procedure if r4 is not zero + */ _GLOBAL(memset_nocache_branch) - b 2f /* Skip optimised bloc until cache is enabled */ + b 2f clrlwi r7,r6,32-LG_CACHELINE_BYTES add r8,r7,r5 -- cgit v1.2.3