Re: [Qemu-devel] [PATCH 2/9] target-ppc: Refactor init_proc_POWER7

[Alexander Graf <agraf@suse.de>]

On 21.05.14 14:30, Alexey Kardashevskiy wrote:
> On 05/21/2014 08:44 PM, Alexander Graf wrote:
>> On 21.05.14 08:20, Alexey Kardashevskiy wrote:
>>> This moves SPR initialization to helper functions.
>>>
>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> I like the idea, but please refactor all book3s CPUs, not just POWER7.
>>
>> I also think we can cover a lot of the SPR registration by matching on
>> feature fields. VR for example is coupled to Altivec.
>
> Ok.
>
>> Maybe we could also introduce an enum for the exact cpu type, similar to
>> how we do it on e500? Then we could do fun things like
>>
>> if (cpu_type >= CPU_TYPE_970) {
>>      gen_spr_book3s_vr(env);
>> }
>>
>> if (cpu_type >= CPU_TYPE_POWER7) {
>>      gen_spr_lpar(env);
>> }
>>
>> switch (cpu_type) {
>>      case CPU_TYPE_POWER7:
>>          env->slb_nr = 32;
>>          break;
>>      default:
>>          env->slb_nr = 64;
>>          break;
>> }
>>
>> and thus combine all those book3s init functions into a single, more
>> maintainable version.
> If I can, I would like not to do it in this way, I'd rather have explicit
> list of gen_spr_FACILITY() calls always. For example,
> DABR/DABRX/whateverPOWER8has - it is not going to be always ">", and this
> breaks my weak mind :(

Could you give me some examples where a newer POWER has lost features 
over an older POWER?


Alex