The instruction_hazard macro made use of the dla pseudo-instruction even
for 32 bit kernels. Although it surrounded that use with ".set mips64rX"
that isn't sufficient to avoid warnings for MIPSr6 CONFIG_32BIT=y
kernels. For example this can be reproduced using maltasmvp_defconfig &
changing only the CPU type to 64r6 (CONFIG_CPU_MIPS64_R6):
CC arch/mips/mm/c-r4k.o
{standard input}: Assembler messages:
{standard input}:4105: Warning: dla used to load 32-bit register;
recommend using la instead
{standard input}:4129: Warning: dla used to load 32-bit register;
recommend using la instead
Avoid this by instead making use of the PTR_LA macro which defines the
appropriate variant of the "la" instruction to use. The .set <isa>
directive is then no longer needed for the la pseudo-instruction, but
needs to remain around the jr.hb for pre-MIPSr2 kernels.
Tested with Codescape GNU Tools 2015.06-05 for MIPS IMG Linux, which
includes binutils 2.24.90 & gcc 4.9.2.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
Changes in v2:
- Leave .set <isa> around jr.hb.
- Describe how to reproduce in the commit message.
arch/mips/include/asm/hazards.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/mips/include/asm/hazards.h b/arch/mips/include/asm/hazards.h
index 7b99efd..835c770 100644
--- a/arch/mips/include/asm/hazards.h
+++ b/arch/mips/include/asm/hazards.h
@@ -11,6 +11,7 @@
#define _ASM_HAZARDS_H
#include <linux/stringify.h>
+#include <asm/asm.h>
#include <asm/compiler.h>
#define ___ssnop \
@@ -65,8 +66,8 @@ do { \
unsigned long tmp; \
\
__asm__ __volatile__( \
+ " " __stringify(PTR_LA) " %0, 1f \n" \
" .set "MIPS_ISA_LEVEL" \n" \
- " dla %0, 1f \n" \
" jr.hb %0 \n" \
" .set mips0 \n" \
"1: \n" \
--
2.7.0
