From 5a7fdcab54ef17c395fc47e73c828a1432e51683 Mon Sep 17 00:00:00 2001 From: Jordan Niethe Date: Wed, 6 May 2020 13:40:24 +1000 Subject: [PATCH] powerpc/xmon: Use bitwise calculations in_breakpoint_table() A modulo operation is used for calculating the current offset from a breakpoint within the breakpoint table. As instruction lengths are always a power of 2, this can be replaced with a bitwise 'and'. The current check for word alignment can be replaced with checking that the lower 2 bits are not set. Suggested-by: Christophe Leroy Signed-off-by: Jordan Niethe Signed-off-by: Michael Ellerman Reviewed-by: Alistair Popple Link: https://lore.kernel.org/r/20200506034050.24806-5-jniethe5@gmail.com --- arch/powerpc/xmon/xmon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 948d025f2939..0fa3aaeee105 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -857,8 +857,8 @@ static struct bpt *in_breakpoint_table(unsigned long nip, unsigned long *offp) off = nip - (unsigned long)bpt_table; if (off >= sizeof(bpt_table)) return NULL; - *offp = off % BPT_SIZE; - if (*offp != 0 && *offp != 4) + *offp = off & (BPT_SIZE - 1); + if (off & 3) return NULL; return bpts + (off / BPT_SIZE); } -- 2.11.0