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 when built with -mabi=32, as
CONFIG_32BIT=y kernels are:
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.
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>
---
arch/mips/include/asm/hazards.h | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/arch/mips/include/asm/hazards.h b/arch/mips/include/asm/hazards.h
index 7b99efd..ffe2aaa 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 \
@@ -54,22 +55,16 @@
/*
* gcc has a tradition of misscompiling the previous construct using the
- * address of a label as argument to inline assembler. Gas otoh has the
- * annoying difference between la and dla which are only usable for 32-bit
- * rsp. 64-bit code, so can't be used without conditional compilation.
- * The alterantive is switching the assembler to 64-bit code which happens
- * to work right even for 32-bit code ...
+ * address of a label as argument to inline assembler.
*/
#define instruction_hazard() \
do { \
unsigned long tmp; \
\
__asm__ __volatile__( \
- " .set "MIPS_ISA_LEVEL" \n" \
- " dla %0, 1f \n" \
- " jr.hb %0 \n" \
- " .set mips0 \n" \
- "1: \n" \
+ __stringify(PTR_LA) " %0, 1f\n\t" \
+ "jr.hb %0\n\t" \
+ "1:" \
: "=r" (tmp)); \
} while (0)
--
2.7.0
