On Oct 28, 2011, at 3:43 PM, Jimi Xenidis wrote:
> arch/powerpc/kernel/head_fsl_booke.S has the following code:
>> /* Data Storage Interrupt */
>> START_EXCEPTION(DataStorage)
>> NORMAL_EXCEPTION_PROLOG
>> mfspr r5,SPRN_ESR /* Grab the ESR, save it, pass arg3 */
>> stw r5,_ESR(r11)
>> mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */
>> andis. r10,r5,(ESR_ILK|ESR_DLK)@h
>> bne 1f
>> EXC_XFER_EE_LITE(0x0300, handle_page_fault)
>> 1:
>> addi r3,r1,STACK_FRAME_OVERHEAD
>> EXC_XFER_EE_LITE(0x0300, CacheLockingException)
>
>
> I need something similar for A2 (and all book3e) and was wondering, why this
> isn't just:
>
>> diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
>> index 88abe70..8451822 100644
>> --- a/arch/powerpc/mm/fault.c
>> +++ b/arch/powerpc/mm/fault.c
>> @@ -159,6 +159,14 @@ int __kprobes do_page_fault(struct pt_regs *regs,
>> unsigned long address,
>> }
>> #endif
>>
>> +#ifdef CONFIG_PPC_BOOK3E
>> + if (error_code & (ESR_DLK|ESR_ILK)) {
>> + /* detect that this is a privileged op and SIGILL */
>> + _exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
>> + return 0;
>> + }
>> +#endif
>> +
>> if (notify_page_fault(regs))
>> return 0;
>
> Its not like this need to be fast or anything.
> I'd be happy to submit a patch that adds to fault.c and removed the I/DLK
> processing from head_fsl_booke.S
>
> Thoughts?
> -jx
Probably because at one point in time DSI had a fast path handling for us.
I've got no issues w/the proposed patch, just remember to mixup the
CONFIG_PPC_BOOK3E as we don't define that in 32-bit fsl-booke
- k
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