On Thu, 23 May 2013, Kim Phillips wrote: > 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: Kim Phillips <kim.phill...@freescale.com> > Reviewed-by: Nicolas Pitre <n...@linaro.org> > Acked-by: David Woodhouse <david.woodho...@intel.com>
Did this ever go somewhere? Russell suggested at the time to base it against a mainline kernel (since it was patching files which apparently were already patched with out-of-tree lz4 patches) and send it to his patch system. > --- > resending as v6 appears to have fallen though the cracks. Russell? > > v7: rebased onto next-20130521, re-ran above vmlinux sizes with > Linaro gcc 4.8, added Nicolas' Reviewed-by, and David's Acked-by. > v6 and prior version information: > https://lkml.org/lkml/2013/2/22/475 > > arch/arm/Kconfig | 1 + > arch/arm/boot/compressed/Makefile | 15 +++++++++++---- > arch/arm/kernel/armksyms.c | 4 ++++ > arch/arm/lib/Makefile | 2 +- > arch/arm/lib/bswapsdi2.S | 36 ++++++++++++++++++++++++++++++++++++ > 5 files changed, 53 insertions(+), 5 deletions(-) > create mode 100644 arch/arm/lib/bswapsdi2.S > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index a7fc5ea..c2fe04d 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -63,6 +63,7 @@ config ARM > select OLD_SIGSUSPEND3 > select OLD_SIGACTION > select HAVE_CONTEXT_TRACKING > + select ARCH_USE_BUILTIN_BSWAP > help > The ARM series is a line of low-power-consumption RISC chip designs > licensed by ARM Ltd and targeted at embedded applications and > diff --git a/arch/arm/boot/compressed/Makefile > b/arch/arm/boot/compressed/Makefile > index 198a4ad..bd8a176 100644 > --- a/arch/arm/boot/compressed/Makefile > +++ b/arch/arm/boot/compressed/Makefile > @@ -112,12 +112,12 @@ 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) $(libfdt_hdrs) > > ifeq ($(CONFIG_FUNCTION_TRACER),y) > ORIG_CFLAGS := $(KBUILD_CFLAGS) > @@ -159,6 +159,12 @@ 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 > @@ -180,7 +186,8 @@ 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) > diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c > index 60d3b73..ba578f7 100644 > --- a/arch/arm/kernel/armksyms.c > +++ b/arch/arm/kernel/armksyms.c > @@ -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); > diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile > index af72969..5383df7 100644 > --- a/arch/arm/lib/Makefile > +++ b/arch/arm/lib/Makefile > @@ -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 > > diff --git a/arch/arm/lib/bswapsdi2.S b/arch/arm/lib/bswapsdi2.S > new file mode 100644 > index 0000000..2ba43a0 > --- /dev/null > +++ b/arch/arm/lib/bswapsdi2.S > @@ -0,0 +1,36 @@ > +#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 > -- > 1.8.1.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
