[OpenBIOS] [PATCH 2/2] arch/ppc/qemu: simplify MMU exception handlers

[BALATON Zoltan]

On Thu, 29 May 2014, Alexander Graf wrote:
> On 28.05.14 21:07, BALATON Zoltan wrote:
>> Remove duplicated code from the handlers for DSI and ISI exceptions.
>> 
>> Signed-off-by: BALATON Zoltan <balaton at eik.bme.hu>
>
> I can't say I'm a big fan of this patch. Jumping from one handler into 
> another is a big red flag to me. If you really think it's worth to 
> consolidate these 3 instructions, please create a separate 
> call_exception_handler function that you call from the DSI and ISI handler.

This is assembly and these are not functions but labels. Jumping to the 
next instruction (like the b exception_return before the exception_return: 
label) is silly.

Regards,
BALATON Zoltan

>
>
> Alex
>
>> ---
>>   openbios-devel/arch/ppc/qemu/start.S | 8 ++------
>>   1 file changed, 2 insertions(+), 6 deletions(-)
>> 
>> diff --git a/openbios-devel/arch/ppc/qemu/start.S 
>> b/openbios-devel/arch/ppc/qemu/start.S
>> index ae2fd53..5aa8c62 100644
>> --- a/openbios-devel/arch/ppc/qemu/start.S
>> +++ b/openbios-devel/arch/ppc/qemu/start.S
>> @@ -359,18 +359,14 @@ VECTOR( 0x2200, "ISI_64" ):
>>   real_dsi:
>>   	EXCEPTION_PREAMBLE
>>   	LOAD_REG_FUNC(r3, dsi_exception)
>> -	mtctr	r3
>> -	bctrl
>> -	b exception_return
>> +	b call_exception_handler
>>     real_isi:
>>   	EXCEPTION_PREAMBLE
>>   	LOAD_REG_FUNC(r3, isi_exception)
>> +call_exception_handler:
>>   	mtctr	r3
>>   	bctrl
>> -	b exception_return
>> -
>> -exception_return:
>>   	EXCEPTION_EPILOGUE
>>     GLOBL(__vectors_end):
>
>