[PATCH] powerpc64/hw_breakpoints: Handle data breakpoints in radix mode

[Michael Ellerman]

"Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com> writes:
> On Wednesday 14 June 2017 10:41 AM, Naveen N. Rao wrote:
>> On 2017/06/14 08:38AM, Aneesh Kumar K.V wrote:
>>> "Naveen N. Rao" <naveen.n.rao at linux.vnet.ibm.com> writes:
>>>> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
>>>> index ae418b85c17c..17ee701b8336 100644
>>>> --- a/arch/powerpc/kernel/exceptions-64s.S
>>>> +++ b/arch/powerpc/kernel/exceptions-64s.S
>>>> @@ -1411,10 +1411,8 @@ USE_TEXT_SECTION()
>>>>   	.balign	IFETCH_ALIGN_BYTES
>>>>   do_hash_page:
>>>>   #ifdef CONFIG_PPC_STD_MMU_64
>>>> -	andis.	r0,r4,0xa410		/* weird error? */
>>>> +	andis.	r0,r4,0xa450		/* weird error? */
>>>
>>> Can we convert that to a #define value. Ram did try to do that here.
>>>
>>> https://lists.ozlabs.org/pipermail/linuxppc-dev/2017-June/158607.html
>> 
>> Hmm... I feel it will be good to do that as part of Ram's series since
>> he has already coded it up :)
>> 
>> Ram's patches will anyway require a rebase and the change I do here for
>> detecting DAWR already has a #define, so it should be a simple matter of
>> including DSISR_DABRMATCH in DSISR_PAGE_FAULT_MASK.
>> 
>> But, if you really feel that I should make that change here, please do
>> let me know and I will re-spin with those changes.
>
> The thing is that change from 0xa410 to 0xa450 is not clear at all. And 
> it needs proper documentation. IMHO the best way to do that is switch to 
> #define name for that constant.

Not in this patch. It needs to be backported, so it should be as minimal
as possible.

The change from 0xa410 to 0xa450 does need a mention in the changelog,
I'll add that.

cheers