From mboxrd@z Thu Jan  1 00:00:00 1970
From: Julien Grall <julien.grall@citrix.com>
Subject: Re: [PATCH v5 10/22] xen/arm: ITS: Add GITS registers
 emulation
Date: Mon, 3 Aug 2015 12:19:16 +0100
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To: Vijay Kilari <vijay.kilari@gmail.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Prasun Kapoor <Prasun.Kapoor@caviumnetworks.com>, manish.jaggi@caviumnetworks.com, Tim Deegan <tim@xen.org>, "xen-devel@lists.xen.org" <xen-devel@lists.xen.org>, Stefano Stabellini <stefano.stabellini@citrix.com>, Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
List-Id: xen-devel@lists.xenproject.org

On 01/08/15 09:50, Vijay Kilari wrote:
> On Wed, Jul 29, 2015 at 12:31 AM, Julien Grall <julien.grall@citrix.com> wrote:
>> Hi Vijay,
>>
>> On 27/07/15 12:11, vijay.kilari@gmail.com wrote:
>>> From: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
>>>
>>> Emulate GITS* registers
>>>
>>> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
>>> ---
>>> v4: - Removed GICR register emulation
>>> ---
> [...]
>>> +    case GITS_PIDR4:
>>> +        if ( dabt.size != DABT_WORD )
>>> +            goto bad_width;
>>> +        *r = GITS_PIDR4_VAL;
>>> +        return 1;
>>> +    case GITS_PIDR5 ... GITS_PIDR7:
>>> +        goto read_as_zero_32;
>>> +   default:
>>> +        dprintk(XENLOG_G_ERR,
>>> +                "%pv: vITS: unhandled read r%"PRId32" offset 0x%#08"PRIx32"\n",
>>
>> Reg is definitely not a PRId32.
> 
> dabt.reg is unsigned long : 5. In vgic-v3.c it is printed using %d.
> [...]
>>> +/*
>>> + * GITS_BASER.Type[58:56], GITS_BASER.Entry_size[55:48]
>>> + * and GITS_BASER.Shareability[11:10] are read-only.
>>
>> As said on v4, implemented Shareability as fixed (i.e read-only) is
>> deprecated. I'd like to see a TODO here.
> 
>   What are you expecting to get fixed for shareability with TODO?

To be more explicit, you are implementing a behavior which is
deprecated. It means that we should avoid to use it knowingly in the
virtual ITS.

In this specific case, I would be ok with a TODO explaining that we need
to fix it or why we need to do read-only.

Regards,

-- 
Julien Grall