Re: [PATCH 4/5] Powerpc/hw-breakpoint: Optimize disable path

From: Ravi Bangoria
Date: Wed Jun 19 2019 - 02:20:08 EST




On 6/18/19 12:01 PM, Christophe Leroy wrote:
>> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
>> index f002d2ffff86..265fac9fb3a4 100644
>> --- a/arch/powerpc/kernel/process.c
>> +++ b/arch/powerpc/kernel/process.c
>> @@ -793,10 +793,22 @@ static inline int set_dabr(struct arch_hw_breakpoint *brk)
>> ÂÂÂÂÂ return __set_dabr(dabr, dabrx);
>> Â }
>> Â +static int disable_dawr(void)
>> +{
>> +ÂÂÂ if (ppc_md.set_dawr)
>> +ÂÂÂÂÂÂÂ return ppc_md.set_dawr(0, 0);
>> +
>> +ÂÂÂ mtspr(SPRN_DAWRX, 0);
>
> And SPRN_DAWR ?

Setting DAWRx with 0 should be enough to disable the breakpoint.