Re: [RFC PATCH v3 10/18] xen/arm: ITS: Add APIs to add and assign device

From: Vijay Kilari <vijay.kilari@gmail.com>
To: Ian Campbell <ian.campbell@citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
	Prasun Kapoor <Prasun.Kapoor@caviumnetworks.com>,
	Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>,
	Tim Deegan <tim@xen.org>,
	"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
	Julien Grall <julien.grall@citrix.com>,
	Stefano Stabellini <stefano.stabellini@citrix.com>,
	manish.jaggi@caviumnetworks.com
Subject: Re: [RFC PATCH v3 10/18] xen/arm: ITS: Add APIs to add and assign device
Date: Thu, 2 Jul 2015 14:10:38 +0530	[thread overview]
Message-ID: <CALicx6tGFMP8fsUOTEk8ofMVqqWn+9S8jvd84T9TrnvdS9-2uQ@mail.gmail.com> (raw)
In-Reply-To: <1435580951.32500.307.camel@citrix.com>

On Mon, Jun 29, 2015 at 5:59 PM, Ian Campbell <ian.campbell@citrix.com> wrote:
> CIOn Mon, 2015-06-22 at 17:31 +0530, vijay.kilari@gmail.com wrote:
>> +/* Device assignment. Should be called from pci_device_add */
>> +int its_add_device(struct domain *d, u32 devid)
>> +{
>
> Prior to the PCI series landing, and to enable dom0 to use ITS it might
> be possible to call this from xen/arch/arm/platforms/thunderx.c via the
> specific_mappings platform hook, which would also expose the PCI
> controller to dom0 via a series of specific mmio mappings (look at
> xen/arch/arm/platforms/xgene-storm.c for the sort of thing I mean).
>
> That would, I think, give basic PCI functionality for dom0 (i.e.
> allowing us to boot on thunderx) and decouple things from the PCI series
> somewhat, which ought to make things easier overall IMHO.

  In case ThunderX, mmio mappings PCI RC is parsed to find devices.
How do we know device ids upfront to call its_add_device?

>
> Ian.
>