From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v4 05/17] xen/arm: ITS: implement hw_irq_controller for LPIs Date: Sat, 18 Jul 2015 11:13:24 +0100 Message-ID: <55AA26C4.9030106@citrix.com> References: <1436514172-3263-1-git-send-email-vijay.kilari@gmail.com> <1436514172-3263-6-git-send-email-vijay.kilari@gmail.com> <55A42B1C.2030600@citrix.com> <55A61940.9010408@citrix.com> <1436952729.11153.28.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1436952729.11153.28.camel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Vijay Kilari , Stefano Stabellini , Prasun Kapoor , Vijaya Kumar K , Tim Deegan , "xen-devel@lists.xen.org" , Stefano Stabellini , manish.jaggi@caviumnetworks.com List-Id: xen-devel@lists.xenproject.org Hi Ian, On 15/07/2015 10:32, Ian Campbell wrote: >> and save 2 byte if not more with the alignment per irq_desc. > > If this is a concern then I would say we would either want a separate > array of per-pLPI information which we do not want in irq_desc because > it is irq specific, or do add a pointer to its_desc which points to an > array of per-event information. I noticed that we have a field msi_desc in the structure irq_desc. On ARM, the structure msi_desc is not defined at all but still waste a 8 byte for the pointer in the irq_desc. Given that LPI is an MSI, I'm wondering if we could move all LPI related data in this msi_desc. This would avoid to introduce new field in the irq_desc structure. The msi_desc would look like: struct msi_desc { its_device *dev; unsigned int eventID; }; Regards, -- Julien Grall