Re: [v2] mips: use wsbh/dsbh/dshd on Loongson 3A

[David Daney <ddaney.cavm@gmail.com>]

On 08/15/2014 01:56 AM, chenj wrote:
> Signed-off-by: chenj <chenj@lemote.com>
> ---
> This patch is modified from http://patchwork.linux-mips.org/patch/7054/
> The original author is ralf.
>
> v2: using "#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_LOONGSON3)"
> instead of "#if cpu_has_wsbh" in csum_partial.S
>
>   arch/mips/include/asm/cpu-features.h                       | 10 ++++++++++
>   .../include/asm/mach-cavium-octeon/cpu-feature-overrides.h |  1 +
>   .../mips/include/asm/mach-loongson/cpu-feature-overrides.h |  2 ++
>   arch/mips/include/uapi/asm/swab.h                          | 14 ++++++++++++--
>   arch/mips/lib/csum_partial.S                               | 10 ++++++++--
>   arch/mips/net/bpf_jit.c                                    |  2 +-
>   6 files changed, 34 insertions(+), 5 deletions(-)
>
[...]
> diff --git a/arch/mips/include/uapi/asm/swab.h b/arch/mips/include/uapi/asm/swab.h
> index ac9a8f9..20b884a 100644
> --- a/arch/mips/include/uapi/asm/swab.h
> +++ b/arch/mips/include/uapi/asm/swab.h
[...]
> @@ -46,8 +53,11 @@ static inline __attribute_const__ __u32 __arch_swab32(__u32 x)
>   static inline __attribute_const__ __u64 __arch_swab64(__u64 x)
>   {
>   	__asm__(
> +	"	.set	push			\n"
> +	"	.set	arch=mips64r2		\n"
>   	"	dsbh	%0, %1\n"
>   	"	dshd	%0, %0"
> +	"	.set	pop			\n"
>   	: "=r" (x)
>   	: "r" (x));
>

This section of the patch is defective.  It appears to have not been 
compile tested.

On mips-for-linux-next commit d4c5edf76f14720a32805202129dfa8206560035 
produces:

.
.
.
   mips64-octeon-linux-gnu-gcc -Wp,-MD,kernel/bpf/.core.o.d  -nostdinc 
-isystem 
/nfs/sdk/daily/tools-140726/bin/../lib/gcc/mips64-octeon-linux-gnu/4.7.0/include 
-I./arch/mips/include -Iarch/mips/include/generated  -Iinclude 
-I./arch/mips/include/uapi -Iarch/mips/include/generated/uapi 
-I./include/uapi -Iinclude/generated/uapi -include 
./include/linux/kconfig.h -D__KERNEL__ 
-DVMLINUX_LOAD_ADDRESS=0xffffffff81100000 -DDATAOFFSET=0 -Wall -Wundef 
-Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common 
-Werror-implicit-function-declaration -Wno-format-security 
-mno-check-zero-division -mabi=64 -G 0 -mno-abicalls -fno-pic -pipe 
-msoft-float -ffreestanding -march=octeon -Wa,--trap -Wa,-mfix-cn63xxp1 
-I./arch/mips/include/asm/mach-cavium-octeon 
-I./arch/mips/include/asm/mach-generic -msym32 -DKBUILD_64BIT_SYM32 
-fno-delete-null-pointer-checks -O2 --param=allow-store-data-races=0 
-Wframe-larger-than=2048 -fno-stack-protector 
-Wno-unused-but-set-variable -fomit-frame-pointer 
-fno-var-tracking-assignments -g -Wdeclaration-after-statement 
-Wno-pointer-sign -fno-strict-overflow -fconserve-stack 
-Werror=implicit-int -Werror=strict-prototypes -DCC_HAVE_ASM_GOTO 
-D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(core)" 
-D"KBUILD_MODNAME=KBUILD_STR(core)" -c -o kernel/bpf/core.o 
kernel/bpf/core.c
{standard input}: Assembler messages:
{standard input}:3016: Error: Illegal operands `dshd $3,$3 .set pop'
.
.
.


Each line except the final line needs to be terminated with a '\n', but 
you did not do this following the "dshd" line.

David Daney