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Commit 017f161a authored by Kim Phillips's avatar Kim Phillips Committed by Russell King
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ARM: 7877/1: use built-in byte swap function 



Enable the compiler intrinsic for byte swapping on arch ARM. This
allows the compiler to detect and be able to optimize out byte
swappings, and has a very modest benefit on vmlinux size (Linaro gcc
4.8):

text data bss dec hex filename
2840310 123932 61960 3026202 2e2d1a vmlinux-lart #orig
2840152 123932 61960 3026044 2e2c7c vmlinux-lart #builtin-bswap

6473120 314840 5616016 12403976 bd4508 vmlinux-mxs #orig
6472586 314848 5616016 12403450 bd42fa vmlinux-mxs #builtin-bswap

7419872 318372 379556 8117800 7bde28 vmlinux-imx_v6_v7 #orig
7419170 318364 379556 8117090 7bdb62 vmlinux-imx_v6_v7 #builtin-bswap

Signed-off-by: default avatarKim Phillips <kim.phillips@freescale.com>
Reviewed-by: default avatarNicolas Pitre <nico@linaro.org>
Acked-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 03aa6580

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ config ARM 
	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST

	select ARCH_HAVE_CUSTOM_GPIO_H

	select ARCH_MIGHT_HAVE_PC_PARPORT

	select ARCH_USE_BUILTIN_BSWAP

	select ARCH_USE_CMPXCHG_LOCKREF

	select ARCH_WANT_IPC_PARSE_VERSION

	select BUILDTIME_EXTABLE_SORT if MMU

arch/arm/boot/compressed/Makefile

+11 −4
Original line number Diff line number Diff line
@@ -108,12 +108,12 @@ endif 


targets       := vmlinux vmlinux.lds \

		 piggy.$(suffix_y) piggy.$(suffix_y).o \

		 lib1funcs.o lib1funcs.S ashldi3.o ashldi3.S \

		 font.o font.c head.o misc.o $(OBJS)

		 lib1funcs.o lib1funcs.S ashldi3.o ashldi3.S bswapsdi2.o \

		 bswapsdi2.S font.o font.c head.o misc.o $(OBJS)



# Make sure files are removed during clean

extra-y       += piggy.gzip piggy.lzo piggy.lzma piggy.xzkern piggy.lz4 \

		 lib1funcs.S ashldi3.S $(libfdt) $(libfdt_hdrs) \

		 lib1funcs.S ashldi3.S bswapsdi2.S $(libfdt) $(libfdt_hdrs) \

		 hyp-stub.S



ifeq ($(CONFIG_FUNCTION_TRACER),y)
@@ -156,6 +156,12 @@ ashldi3 = $(obj)/ashldi3.o 
$(obj)/ashldi3.S: $(srctree)/arch/$(SRCARCH)/lib/ashldi3.S

	$(call cmd,shipped)



# For __bswapsi2, __bswapdi2

bswapsdi2 = $(obj)/bswapsdi2.o



$(obj)/bswapsdi2.S: $(srctree)/arch/$(SRCARCH)/lib/bswapsdi2.S

	$(call cmd,shipped)



# We need to prevent any GOTOFF relocs being used with references

# to symbols in the .bss section since we cannot relocate them

# independently from the rest at run time.  This can be achieved by
@@ -177,7 +183,8 @@ if [ $(words $(ZRELADDR)) -gt 1 -a "$(CONFIG_AUTO_ZRELADDR)" = "" ]; then \ 
fi



$(obj)/vmlinux: $(obj)/vmlinux.lds $(obj)/$(HEAD) $(obj)/piggy.$(suffix_y).o \

		$(addprefix $(obj)/, $(OBJS)) $(lib1funcs) $(ashldi3) FORCE

		$(addprefix $(obj)/, $(OBJS)) $(lib1funcs) $(ashldi3) \

		$(bswapsdi2) FORCE

	@$(check_for_multiple_zreladdr)

	$(call if_changed,ld)

	@$(check_for_bad_syms)

arch/arm/kernel/armksyms.c

+4 −0
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ extern void __ucmpdi2(void); 
extern void __udivsi3(void);

extern void __umodsi3(void);

extern void __do_div64(void);

extern void __bswapsi2(void);

extern void __bswapdi2(void);



extern void __aeabi_idiv(void);

extern void __aeabi_idivmod(void);
@@ -114,6 +116,8 @@ EXPORT_SYMBOL(__ucmpdi2); 
EXPORT_SYMBOL(__udivsi3);

EXPORT_SYMBOL(__umodsi3);

EXPORT_SYMBOL(__do_div64);

EXPORT_SYMBOL(__bswapsi2);

EXPORT_SYMBOL(__bswapdi2);



#ifdef CONFIG_AEABI

EXPORT_SYMBOL(__aeabi_idiv);

arch/arm/lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \ 
		   ashldi3.o ashrdi3.o lshrdi3.o muldi3.o             \

		   ucmpdi2.o lib1funcs.o div64.o                      \

		   io-readsb.o io-writesb.o io-readsl.o io-writesl.o  \

		   call_with_stack.o

		   call_with_stack.o bswapsdi2.o



mmu-y	:= clear_user.o copy_page.o getuser.o putuser.o

arch/arm/lib/bswapsdi2.S

0 → 100644
+36 −0
Original line number Diff line number Diff line 
#include <linux/linkage.h>



#if __LINUX_ARM_ARCH__ >= 6

ENTRY(__bswapsi2)

	rev r0, r0

	bx lr

ENDPROC(__bswapsi2)



ENTRY(__bswapdi2)

	rev r3, r0

	rev r0, r1

	mov r1, r3

	bx lr

ENDPROC(__bswapdi2)

#else

ENTRY(__bswapsi2)

	eor r3, r0, r0, ror #16

	mov r3, r3, lsr #8

	bic r3, r3, #0xff00

	eor r0, r3, r0, ror #8

	mov pc, lr

ENDPROC(__bswapsi2)



ENTRY(__bswapdi2)

	mov ip, r1

	eor r3, ip, ip, ror #16

	eor r1, r0, r0, ror #16

	mov r1, r1, lsr #8

	mov r3, r3, lsr #8

	bic r3, r3, #0xff00

	bic r1, r1, #0xff00

	eor r1, r1, r0, ror #8

	eor r0, r3, ip, ror #8

	mov pc, lr

ENDPROC(__bswapdi2)

#endif