Re: [Qemu-devel] [PATCH 2/5] target-ppc: USE LPCR_ILE to control exception endian on POWER7

[Anthony Liguori <aliguori@us.ibm.com>]

Andreas Färber <afaerber@suse.de> writes:

> Am 07.08.2013 02:47, schrieb Anton Blanchard:
>> On POWER7, LPCR_ILE is used to control what endian guests take
>> their exceptions in so use it instead of MSR_ILE.
>> 
>> Signed-off-by: Anton Blanchard <anton@samba.org>
>> ---
>>  target-ppc/cpu.h         |  2 ++
>>  target-ppc/excp_helper.c | 10 ++++++++++
>>  2 files changed, 12 insertions(+)
>> 
>> diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
>> index 711db08..422a6bb 100644
>> --- a/target-ppc/cpu.h
>> +++ b/target-ppc/cpu.h
>> @@ -453,6 +453,8 @@ struct ppc_slb_t {
>>  #define MSR_RI   1  /* Recoverable interrupt                        1        */
>>  #define MSR_LE   0  /* Little-endian mode                           1 hflags */
>>  
>> +#define LPCR_ILE (1 << (63-38))
>> +
>>  #define msr_sf   ((env->msr >> MSR_SF)   & 1)
>>  #define msr_isf  ((env->msr >> MSR_ISF)  & 1)
>>  #define msr_shv  ((env->msr >> MSR_SHV)  & 1)
>> diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
>> index e9fcad8..e957761 100644
>> --- a/target-ppc/excp_helper.c
>> +++ b/target-ppc/excp_helper.c
>> @@ -611,9 +611,19 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int excp_model, int excp)
>>          tlb_flush(env, 1);
>>      }
>>  
>> +#ifdef TARGET_PPC64
>> +    if (excp_model == POWERPC_EXCP_POWER7) {
>> +        if (env->spr[SPR_LPCR] & LPCR_ILE) {
>> +            new_msr |= (target_ulong)1 << MSR_LE;
>> +        }
>> +    } else if (msr_ile) {
>> +        new_msr |= (target_ulong)1 << MSR_LE;
>> +    }
>> +#else
>
> You could just do
>
> ...
>     } else
> #endif
>
> to spare duplicating the msr_ile path.

If the condition was more complicated, I'd agree, but I really dislike
splitting statements up via an #ifdef.

Regards,

Anthony Liguori

>
> Andreas
>
>>      if (msr_ile) {
>>          new_msr |= (target_ulong)1 << MSR_LE;
>>      }
>> +#endif
>>  
>>      /* Jump to handler */
>>      vector = env->excp_vectors[excp];
>> 
>
>
> -- 
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