From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753639Ab3IFOyU (ORCPT ); Fri, 6 Sep 2013 10:54:20 -0400 Received: from smtp.citrix.com ([66.165.176.89]:10360 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752169Ab3IFOyS (ORCPT ); Fri, 6 Sep 2013 10:54:18 -0400 X-IronPort-AV: E=Sophos;i="4.90,854,1371081600"; d="scan'208";a="51287090" Date: Fri, 6 Sep 2013 15:53:58 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Konrad Rzeszutek Wilk CC: Catalin Marinas , Ian Campbell , Stefano Stabellini , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH v5 05/13] xen/arm,arm64: move Xen initialization earlier In-Reply-To: <20130906142301.GA5140@phenom.dumpdata.com> Message-ID: References: <1377801154-29215-5-git-send-email-stefano.stabellini@eu.citrix.com> <20130905162026.GJ11887@arm.com> <1378457939.14745.73.camel@kazak.uk.xensource.com> <20130906140921.GD1946@arm.com> <20130906142301.GA5140@phenom.dumpdata.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 6 Sep 2013, Konrad Rzeszutek Wilk wrote: > On Fri, Sep 06, 2013 at 03:09:21PM +0100, Catalin Marinas wrote: > > On Fri, Sep 06, 2013 at 09:58:59AM +0100, Ian Campbell wrote: > > > On Thu, 2013-09-05 at 17:59 +0100, Stefano Stabellini wrote: > > > > On Thu, 5 Sep 2013, Catalin Marinas wrote: > > > > > On Thu, Aug 29, 2013 at 07:32:26PM +0100, Stefano Stabellini wrote: > > > > > > Move Xen initialization earlier, before any DMA requests can be made. > > > > > > > > > > > > Signed-off-by: Stefano Stabellini > > > > > > > > > > I guess you should cc the corresponding maintainers here. > > > > > > > > Thanks for the reminder, I'll do that. > > > > > > > > > > > > > > arch/arm/include/asm/xen/hypervisor.h | 8 ++++++++ > > > > > > arch/arm/kernel/setup.c | 2 ++ > > > > > > arch/arm/xen/enlighten.c | 21 ++++++++++++++------- > > > > > > arch/arm64/kernel/setup.c | 2 ++ > > > > > > 4 files changed, 26 insertions(+), 7 deletions(-) > > > > > > > > > > [...] > > > > > > > > > > > --- a/arch/arm64/kernel/setup.c > > > > > > +++ b/arch/arm64/kernel/setup.c > > > > > > @@ -53,6 +53,7 @@ > > > > > > #include > > > > > > #include > > > > > > #include > > > > > > +#include > > > > > > > > > > > > unsigned int processor_id; > > > > > > EXPORT_SYMBOL(processor_id); > > > > > > @@ -267,6 +268,7 @@ void __init setup_arch(char **cmdline_p) > > > > > > unflatten_device_tree(); > > > > > > > > > > > > psci_init(); > > > > > > + xen_early_init(); > > > > > > > > > > So Xen guests don't have any hope for single Image? Basically you set > > > > > dma_ops unconditionally in xen_early_init(), even if the kernel is not > > > > > intended to run under Xen. > > > > > > > > That should not happen: if we are not running on Xen xen_early_init > > > > returns early, before calling xen_mm_init. > > > > > > x96 has a call to init_hypervisor_platform() at approximately this > > > location, which detects and calls the init function for any of Xen, KVM, > > > hyperv and vmware. > > > > I would rather have a core_initcall(xen_early_init()) if possible, > > rather than hard-coded calls in setup_arch(). This early stuff is > > DT-driven, so in theory you don't need a specific xen call. The only > > thing is that you end up with swiotlb_init() and 64MB wasted if the Xen > > guest does not plan to use them. > > There is a swiotlb_free mechanism in case the allocation was not > neccessary. I think I'll just use the late swiotlb initialization.