[PATCH] ARM: cacheflush: Fix exynos build breakage on ARMv6 by using macros for ISB/DSB

From: Krzysztof Kozlowski
Date: Tue Sep 16 2014 - 08:53:26 EST


This fixes build breakage of platsmp.c if ARMv6 was chosen for compile
time options (e.g. by building allmodconfig):

$ make allmodconfig
$ make
CC arch/arm/mach-exynos/platsmp.o
/tmp/ccdQM0Eg.s: Assembler messages:
/tmp/ccdQM0Eg.s:432: Error: selected processor does not support ARM mode `isb '
/tmp/ccdQM0Eg.s:437: Error: selected processor does not support ARM mode `isb '
/tmp/ccdQM0Eg.s:438: Error: selected processor does not support ARM mode `dsb '
make[1]: *** [arch/arm/mach-exynos/platsmp.o] Error 1

The error was introduced in commit "ARM: EXYNOS: Move code from
hotplug.c to platsmp.c". Previously code using
v7_exit_coherency_flush() macro was built with '-march=armv7-a' flag but
this flag dissapeared during the movement.

Use isb() and dsb() macros in v7_exit_coherency_flush() so the proper
code will be generated for ARMv6.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
Reported-by: Mark Brown <broonie@xxxxxxxxxx>
Link: http://www.spinics.net/lists/linux-samsung-soc/msg36790.html
---
arch/arm/include/asm/cacheflush.h | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index 79ecb4f34ffb..b74eeec971c0 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/arch/arm/include/asm/cacheflush.h
@@ -464,22 +464,27 @@ static inline void __sync_cache_range_r(volatile void *p, size_t size)
* CONFIG_FRAME_POINTER=y. ip is saved as well if ever r12-clobbering
* trampoline are inserted by the linker and to keep sp 64-bit aligned.
*/
-#define v7_exit_coherency_flush(level) \
+#define v7_exit_coherency_flush(level) do { \
asm volatile( \
"stmfd sp!, {fp, ip} \n\t" \
"mrc p15, 0, r0, c1, c0, 0 @ get SCTLR \n\t" \
"bic r0, r0, #"__stringify(CR_C)" \n\t" \
"mcr p15, 0, r0, c1, c0, 0 @ set SCTLR \n\t" \
- "isb \n\t" \
+ : : : "r0","r1","r2","r3","r4","r5","r6","r7", \
+ "r9","r10","lr","memory" ); \
+ isb(); \
+ asm volatile( \
"bl v7_flush_dcache_"__stringify(level)" \n\t" \
"mrc p15, 0, r0, c1, c0, 1 @ get ACTLR \n\t" \
"bic r0, r0, #(1 << 6) @ disable local coherency \n\t" \
"mcr p15, 0, r0, c1, c0, 1 @ set ACTLR \n\t" \
- "isb \n\t" \
- "dsb \n\t" \
- "ldmfd sp!, {fp, ip}" \
: : : "r0","r1","r2","r3","r4","r5","r6","r7", \
- "r9","r10","lr","memory" )
+ "r9","r10","lr","memory" ); \
+ isb(); \
+ dsb(); \
+ asm volatile( \
+ "ldmfd sp!, {fp, ip}" ); \
+ } while (0)

int set_memory_ro(unsigned long addr, int numpages);
int set_memory_rw(unsigned long addr, int numpages);
--
1.9.1

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