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Subject: Re: [PATCH v2 06/16] powerpc/watchpoint: Provide DAWR number to
 __set_breakpoint
From:   Christophe Leroy <christophe.leroy@c-s.fr>
To:     Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc:     apopple@linux.ibm.com, mikey@neuling.org, peterz@infradead.org,
        oleg@redhat.com, npiggin@gmail.com, linux-kernel@vger.kernel.org,
        paulus@samba.org, jolsa@kernel.org, fweisbec@gmail.com,
        naveen.n.rao@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org,
        mingo@kernel.org
References: <20200401061309.92442-1-ravi.bangoria@linux.ibm.com>
 <20200401061309.92442-7-ravi.bangoria@linux.ibm.com>
 <89f43001-0fa4-1394-4158-878fca4962e3@c-s.fr>
 <cb9ccaa1-9ea2-c3d7-4724-f75ebff4b66d@linux.ibm.com>
 <d62efd40-4aa6-01e5-a669-3590b121c0f8@c-s.fr>
Message-ID: <f6a3ac3b-41c8-8a18-0f3d-ea4d4ef04db1@c-s.fr>
Date:   Wed, 1 Apr 2020 11:44:11 +0200
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Le 01/04/2020 à 11:11, Christophe Leroy a écrit :
> 
> 
> Le 01/04/2020 à 10:57, Ravi Bangoria a écrit :
>>
>>
>> On 4/1/20 12:33 PM, Christophe Leroy wrote:
>>>
>>>
>>> Le 01/04/2020 à 08:12, Ravi Bangoria a écrit :
>>>> Introduce new parameter 'nr' to __set_breakpoint() which indicates
>>>> which DAWR should be programed. Also convert current_brk variable
>>>> to an array.
>>>>
>>>> Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
>>>> ---
>>>>   arch/powerpc/include/asm/debug.h         |  2 +-
>>>>   arch/powerpc/include/asm/hw_breakpoint.h |  2 +-
>>>>   arch/powerpc/kernel/hw_breakpoint.c      |  8 ++++----
>>>>   arch/powerpc/kernel/process.c            | 14 +++++++-------
>>>>   arch/powerpc/kernel/signal.c             |  2 +-
>>>>   arch/powerpc/xmon/xmon.c                 |  2 +-
>>>>   6 files changed, 15 insertions(+), 15 deletions(-)
>>>>
>>>> diff --git a/arch/powerpc/include/asm/debug.h 
>>>> b/arch/powerpc/include/asm/debug.h
>>>> index 7756026b95ca..6228935a8b64 100644
>>>> --- a/arch/powerpc/include/asm/debug.h
>>>> +++ b/arch/powerpc/include/asm/debug.h
>>>> @@ -45,7 +45,7 @@ static inline int debugger_break_match(struct 
>>>> pt_regs *regs) { return 0; }
>>>>   static inline int debugger_fault_handler(struct pt_regs *regs) { 
>>>> return 0; }
>>>>   #endif
>>>> -void __set_breakpoint(struct arch_hw_breakpoint *brk);
>>>> +void __set_breakpoint(struct arch_hw_breakpoint *brk, int nr);
>>>
>>> Same, I think it would make more sense to have nr as first argument.
>>
>> Sorry, didn't get your point. How will that help?
>>
> 
> Well, it is a tiny detail but for me it is more natural to first tel 
> which element you modify before telling how you modify it.
> 

And the second advantage is that when you have a function 
get_something() paired with you set_something(), you can then have it as 
first argument in both functions.

void set_something(int nr, type something)
type get_something(int nr)

But again, that's detail, so up to you.

Christophe