From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:34641)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <agraf@suse.de>) id 1Wn6dV-0005wH-Fx
	for qemu-devel@nongnu.org; Wed, 21 May 2014 09:32:55 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <agraf@suse.de>) id 1Wn6dP-00015R-7w
	for qemu-devel@nongnu.org; Wed, 21 May 2014 09:32:49 -0400
Message-ID: <537CA8EF.10208@suse.de>
Date: Wed, 21 May 2014 15:23:59 +0200
From: Alexander Graf <agraf@suse.de>
MIME-Version: 1.0
References: <1400653228-31540-1-git-send-email-aik@ozlabs.ru>
	<1400653228-31540-3-git-send-email-aik@ozlabs.ru>
	<537C83A9.6010603@suse.de> <537C9C77.1010402@ozlabs.ru>
In-Reply-To: <537C9C77.1010402@ozlabs.ru>
Content-Type: text/plain; charset=KOI8-R; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH 2/9] target-ppc: Refactor init_proc_POWER7
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Alexey Kardashevskiy <aik@ozlabs.ru>, qemu-devel@nongnu.org
Cc: Tom Musta <tommusta@gmail.com>, qemu-ppc@nongnu.org


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