[PATCH 5/9] Replace 8 nops with proper sync instruction on mips

[David Daney]

Matt Turner wrote:
> Cc: David Daney <ddaney at caviumnetworks.com>

Acked-by: David Daney <ddaney at caviumnetworks.com>

(for whatever that's worth)



> Cc: Ralf Baechle <ralf at linux-mips.org>
> Signed-off-by: Matt Turner <mattst88 at gmail.com>
> ---
>  hw/xfree86/common/compiler.h |   21 +++++++++++----------
>  1 files changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/xfree86/common/compiler.h b/hw/xfree86/common/compiler.h
> index 8ea19b3..2fc1e6a 100644
> --- a/hw/xfree86/common/compiler.h
> +++ b/hw/xfree86/common/compiler.h
> @@ -165,16 +165,17 @@ extern unsigned short ldw_brx(volatile unsigned char *, int);
>  #    endif
>  
>  #   elif defined __mips__
> -#    define mem_barrier() \
> -        __asm__ __volatile__(                                   \
> -                "# prevent instructions being moved around\n\t" \
> -                ".set\tnoreorder\n\t"                           \
> -                "# 8 nops to fool the R4400 pipeline\n\t"       \
> -                "nop;nop;nop;nop;nop;nop;nop;nop\n\t"           \
> -                ".set\treorder"                                 \
> -                : /* no output */                               \
> -                : /* no input */                                \
> -                : "memory")
> +     /* Note: sync instruction requires MIPS II instruction set */
> +#    define mem_barrier()		\
> +	__asm__ __volatile__(		\
> +		".set   push\n\t"	\
> +		".set   noreorder\n\t"	\
> +		".set   mips2\n\t"	\
> +		"sync\n\t"		\
> +		".set   pop"		\
> +		: /* no output */	\
> +		: /* no input */	\
> +		: "memory")
>  #    define write_mem_barrier() mem_barrier()
>  
>  #   elif defined __powerpc__