Re: [PATCH RFC 12/67] MIPS: asm: asmmacro: Replace add instructions with "addui"

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

On 12/18/2014 07:09 AM, Markos Chandras wrote:
> The use of "add" instruction for immediate operations is wrong and
> relies to gas being smart enough to notice that and replace it with
> either addi or addui. However, MIPS R6 removed the addi instruction
> so, fix this problem properly by using the correct instruction
> directly.
>

This is another case of the use of "add" being a real bug.  We should 
never have faulting instructions like this in the kernel.

Can you send all patches in this set that fix this bug as a separate 
patch?  Since they are obviously correct, and really should be used by 
all non-R6 processors, we can get them in sooner that the entire R6 thing.

Thanks,
David Daney

> Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
> ---
>   arch/mips/include/asm/asmmacro.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h
> index fe08084f5adb..55c07c40c199 100644
> --- a/arch/mips/include/asm/asmmacro.h
> +++ b/arch/mips/include/asm/asmmacro.h
> @@ -304,7 +304,7 @@
>   	.set	push
>   	.set	noat
>   	SET_HARDFLOAT
> -	add	$1, \base, \off
> +	addiu	$1, \base, \off
>   	.word	LDD_MSA_INSN | (\wd << 6)
>   	.set	pop
>   	.endm
> @@ -313,7 +313,7 @@
>   	.set	push
>   	.set	noat
>   	SET_HARDFLOAT
> -	add	$1, \base, \off
> +	addiu	$1, \base, \off
>   	.word	STD_MSA_INSN | (\wd << 6)
>   	.set	pop
>   	.endm
>