[PATCH v3 3/3] [POWERPC] 40x/Book-E: Save/restore volatile exception registers

[Kumar Gala]

>> <snip>
>
>> --- a/arch/powerpc/kernel/entry_32.S
>> +++ b/arch/powerpc/kernel/entry_32.S
>
> <snip>
>
>> +#ifdef CONFIG_40x
>> 	.globl	ret_from_crit_exc
>> ret_from_crit_exc:
>> +	mfspr	r9,SPRN_SPRG3
> 	lis 	r10,saved_ksp_limit at ha;
> 	lwz	r10,saved_ksp_limit at l(r10);
> 	tovirt(r9,r9);
>> +	stw	r10,KSP_LIMIT(r9)
> 	lis	r9, crit_srr0 at ha;
> 	lwz	r9, crit_srr0 at l(r9);
> 	lis	r10, crit_srr1 at ha;
> 	lwz	r10, crit_srr1 at l(r10);
>> +	mtspr	SPRN_SRR0,r9;
>> +	mtspr	SPRN_SRR1,r10;
>> 	RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, RFCI)
>> +#endif /* CONFIG_40x */
>
> With the above changes, I no longer get kernel panics on returning  
> from
> critical exceptions.  Breakpoints and single stepping worked on my
> 405GP board.
>
> Again, not stress tested but it's looking much better.
>
> josh

Thanks.  I've just posted v5 with the various fixes for 40x.  Can you  
test those out to make sure they still work.

- k