Re: [Qemu-devel] [PATCH qom-cpu-next] ppce500_spin: Replace open-coded CPU loop with qemu_get_cpu()

[Andreas Färber]

Am 15.02.2013 17:54, schrieb Alexander Graf:
> 
> On 15.02.2013, at 17:51, Andreas Färber wrote:
> 
>> Potentially env could be NULL whereas cpu would still be valid and
>> correspond to a previous env.
>>
>> Wrapping this in qemu_get_cpu(), env is no longer needed, so simplify
>> code that existed before 55e5c2850293547203874098f7cec148ffd12dfa.
>>
>> Signed-off-by: Andreas Färber <address@hidden>
>> ---
>> hw/ppce500_spin.c |   15 ++++-----------
>> 1 Datei geändert, 4 Zeilen hinzugefügt(+), 11 Zeilen entfernt(-)
>>
>> diff --git a/hw/ppce500_spin.c b/hw/ppce500_spin.c
>> index 7e90fb9..5bdce52 100644
>> --- a/hw/ppce500_spin.c
>> +++ b/hw/ppce500_spin.c
>> @@ -123,18 +123,11 @@ static void spin_write(void *opaque, hwaddr addr, 
>> uint64_t value,
>> {
>>     SpinState *s = opaque;
>>     int env_idx = addr / sizeof(SpinInfo);
>> -    CPUPPCState *env;
>> -    CPUState *cpu = NULL;
>> +    CPUState *cpu;
>>     SpinInfo *curspin = &s->spin[env_idx];
>>     uint8_t *curspin_p = (uint8_t*)curspin;
>>
>> -    for (env = first_cpu; env != NULL; env = env->next_cpu) {
>> -        cpu = CPU(ppc_env_get_cpu(env));
>> -        if (cpu->cpu_index == env_idx) {
>> -            break;
>> -        }
>> -    }
>> -
>> +    cpu = qemu_get_cpu(env_idx);
>>     if (cpu == NULL) {
>>         /* Unknown CPU */
>>         return;
>> @@ -161,11 +154,11 @@ static void spin_write(void *opaque, hwaddr addr, 
>> uint64_t value,
>>     if (!(ldq_p(&curspin->addr) & 1)) {
>>         /* run CPU */
>>         SpinKick kick = {
>> -            .cpu = ppc_env_get_cpu(env),
>> +            .cpu = POWERPC_CPU(cpu),
> 
> Why not just cpu?

PowerPCCPU vs. CPUState type.
Having the specific type in ppc code allows direct access to ->env.

If you see a performance issue, we could also use (PowerPCCPU *)cpu.

Andreas

>>             .spin = curspin,
>>         };
>>
>> -        run_on_cpu(CPU(kick.cpu), spin_kick, &kick);
>> +        run_on_cpu(cpu, spin_kick, &kick);
>>     }
>> }
>>
>> -- 
>> 1.7.10.4
>>
> 


-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg