Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757050Ab1BRONJ (ORCPT ); Fri, 18 Feb 2011 09:13:09 -0500 Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:41662 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750775Ab1BRONI (ORCPT ); Fri, 18 Feb 2011 09:13:08 -0500 X-IronPort-AV: E=Sophos;i="4.62,187,1297036800"; d="scan'208";a="4398726" Date: Fri, 18 Feb 2011 14:13:08 +0000 From: Stefano Stabellini X-X-Sender: sstabellini@kaball-desktop To: Ian Campbell CC: Konrad Rzeszutek Wilk , Konrad Rzeszutek Wilk , Jeremy Fitzhardinge , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , Stefano Stabellini Subject: Re: [Xen-devel] [PATCH 1/3] pci/xen: Use xen_allocate_pirq_msi In-Reply-To: <1298038278.16356.3315.camel@zakaz.uk.xensource.com> Message-ID: References: <1297894638-28007-1-git-send-email-konrad.wilk@oracle.com> <1297894638-28007-2-git-send-email-konrad.wilk@oracle.com> <1297932091.16356.1292.camel@zakaz.uk.xensource.com> <20110217143003.GE5987@dumpdata.com> <20110218140729.GA8446@dumpdata.com> <1298038278.16356.3315.camel@zakaz.uk.xensource.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2679 Lines: 63 On Fri, 18 Feb 2011, Ian Campbell wrote: > On Fri, 2011-02-18 at 14:07 +0000, Konrad Rzeszutek Wilk wrote: > > On Thu, Feb 17, 2011 at 09:30:03AM -0500, Konrad Rzeszutek Wilk wrote: > > > On Thu, Feb 17, 2011 at 08:41:31AM +0000, Ian Campbell wrote: > > > > On Wed, 2011-02-16 at 22:17 +0000, Konrad Rzeszutek Wilk wrote: > > > > > There is no need to use the old interface. > > > > > > > > xen_allocate_pirq -> xen_map_pirq_gsi -> PHYSDEVOP_alloc_irq_vector IFF > > > > xen_initial_domain() in addition to the kernel side book-keeping side of > > > > things (set chip and handler, update irq_info etc) whereas > > > > xen_allocate_pirq_msi just does the kernel book keeping. > > > > > > > > Also xen_allocate_pirq allocates an IRQ in the 1-1 GSI space whereas > > > > xen_allocate_pirq_msi allocates a dynamic one in the >GSI IRQ space. > > > > > > Which is OK. These are MSIs. > > > > > > > > So this change is actually a semantic change and not just a switch to a > > > > new interface. I think the change is OK (because the caller is domU > > > > > > Right. > > > > > > > only?) but a comment explaining this would be appreciated. > > > > > > Correct: "domU side". > > > > > > Will fix it up. > > > > How does this look to you? > > > > From eb832bece3131ecbdb509f7f2a9bc53f6692177c Mon Sep 17 00:00:00 2001 > > From: Konrad Rzeszutek Wilk > > Date: Wed, 16 Feb 2011 13:43:04 -0500 > > Subject: [PATCH 3/5] pci/xen: Use xen_allocate_pirq_msi instead of xen_allocate_pirq > > > > xen_allocate_pirq -> xen_map_pirq_gsi -> PHYSDEVOP_alloc_irq_vector IFF > > xen_initial_domain() in addition to the kernel side book-keeping side of > > things (set chip and handler, update irq_info etc) whereas > > xen_allocate_pirq_msi just does the kernel book keeping. > > > > Also xen_allocate_pirq allocates an IRQ in the 1-1 GSI space whereas > > xen_allocate_pirq_msi allocates a dynamic one in the >GSI IRQ space. > > > > All of this is uneccessary as this code path is only executed > > when we run as a domU PV guest with an MSI/MSI-X PCI card passed in. > > Hence we can jump straight to allocating an dynamic IRQ (and > > binding it to the proper PIRQ) and skip the rest. > > > > In short: this change is a cosmetic one. > > > > Signed-off-by: Konrad Rzeszutek Wilk > > Looks good, > > Reviewed-by: Ian Campbell You can add my reviewed-by too. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/