From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FAKE_REPLY_C,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38C8FC10F14 for ; Thu, 3 Oct 2019 19:04:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A17521783 for ; Thu, 3 Oct 2019 19:04:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570129456; bh=vAeRwJKvjbppfRBis3EbbpF4j0rxFqnsnF2TXByRbmo=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=Jc8tAUYxov3WHHKOKmIatK8A4hA8mDOFZk3xZUR/7EQKQEG9HDskmopxTsc1NtM6x h2CHl0A7KqMYS7inPmqgFqtJDmSndHAHJqS/ncB+VVTExFYn+DPxZwmfOjWkgcKOSQ r56rzNhp5wnqX75fgzoQ8xLWAXAaKdmnn4XJf8T0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730841AbfJCTEP (ORCPT ); Thu, 3 Oct 2019 15:04:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:40602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729781AbfJCTEP (ORCPT ); Thu, 3 Oct 2019 15:04:15 -0400 Received: from localhost (odyssey.drury.edu [64.22.249.253]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E9E0820873; Thu, 3 Oct 2019 19:04:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570129454; bh=vAeRwJKvjbppfRBis3EbbpF4j0rxFqnsnF2TXByRbmo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=j5K/MZWAGs45oDd0H/WdAqAas6kh46mqHu00SaeIrkWbHniADzR9es/QNTsjD906q OtJfWCDu7qD/aBppFeUjwZZlOSYhi3wZDVfAVoSrtiTUbn3fq1JcqbaOWXPHvjy6lo +RAJsN6+3a8wfCcJDGbjCMvBxDZ9a6aMxZ+ajjaY= Date: Thu, 3 Oct 2019 14:04:13 -0500 From: Bjorn Helgaas To: Kuppuswamy Sathyanarayanan Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, keith.busch@intel.com Subject: Re: [PATCH v7 1/7] PCI/ATS: Fix pci_prg_resp_pasid_required() dependency issues Message-ID: <20191003190413.GA182793@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Oct 03, 2019 at 10:20:24AM -0700, Kuppuswamy Sathyanarayanan wrote: > Hi Bjorn, > > Thanks for looking into this patch set. > > On 9/5/19 12:18 PM, Bjorn Helgaas wrote: > > On Wed, Aug 28, 2019 at 03:14:01PM -0700, sathyanarayanan.kuppuswamy@linux.intel.com wrote: > > > From: Kuppuswamy Sathyanarayanan > > > > > > Since pci_prg_resp_pasid_required() function has dependency on both > > > PASID and PRI, define it only if both CONFIG_PCI_PRI and > > > CONFIG_PCI_PASID config options are enabled. > > > > > > Fixes: e5567f5f6762 ("PCI/ATS: Add pci_prg_resp_pasid_required() > > > interface.") > > [Don't split tags, including "Fixes:" across lines] > > > > This definitely doesn't fix e5567f5f6762. That commit added > > pci_prg_resp_pasid_required(), but with no dependency on > > CONFIG_PCI_PRI or CONFIG_PCI_PASID. > > > > This patch is only required when a subsequent patch is applied. It > > should be squashed into the commit that requires it so it's obvious > > why it's needed. > > > > I've been poking at this series, and I'll post a v8 soon with this and > > other fixes. > In your v8 submission you did not merge this patch. You did not use > pri_cap or pasid_cap cached values. Instead you have re-read the > value from register. Is this intentional? > > Since this function will be called for every VF device we might loose some > performance benefit. This particular patch doesn't do any caching. IIRC it fiddles with ifdefs to solve a problem that would be introduced by a future patch. I don't remember the exact details, but I think the series I merged doesn't have that problem. If it does, let me know the details and we can fix it. I did include the caching patches for both PRI and PASID capabilities, but they're only performance optimizations so I moved them to the end so the functional fixes would be smaller and earlier in the series. > > > Signed-off-by: Kuppuswamy Sathyanarayanan > > > --- > > > drivers/pci/ats.c | 10 ++++++---- > > > include/linux/pci-ats.h | 12 +++++++++--- > > > 2 files changed, 15 insertions(+), 7 deletions(-) > > > > > > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c > > > index e18499243f84..cdd936d10f68 100644 > > > --- a/drivers/pci/ats.c > > > +++ b/drivers/pci/ats.c > > > @@ -395,6 +395,8 @@ int pci_pasid_features(struct pci_dev *pdev) > > > } > > > EXPORT_SYMBOL_GPL(pci_pasid_features); > > > +#ifdef CONFIG_PCI_PRI > > > + > > > /** > > > * pci_prg_resp_pasid_required - Return PRG Response PASID Required bit > > > * status. > > > @@ -402,10 +404,8 @@ EXPORT_SYMBOL_GPL(pci_pasid_features); > > > * > > > * Returns 1 if PASID is required in PRG Response Message, 0 otherwise. > > > * > > > - * Even though the PRG response PASID status is read from PRI Status > > > - * Register, since this API will mainly be used by PASID users, this > > > - * function is defined within #ifdef CONFIG_PCI_PASID instead of > > > - * CONFIG_PCI_PRI. > > > + * Since this API has dependency on both PRI and PASID, protect it > > > + * with both CONFIG_PCI_PRI and CONFIG_PCI_PASID. > > > */ > > > int pci_prg_resp_pasid_required(struct pci_dev *pdev) > > > { > > > @@ -425,6 +425,8 @@ int pci_prg_resp_pasid_required(struct pci_dev *pdev) > > > } > > > EXPORT_SYMBOL_GPL(pci_prg_resp_pasid_required); > > > +#endif > > > + > > > #define PASID_NUMBER_SHIFT 8 > > > #define PASID_NUMBER_MASK (0x1f << PASID_NUMBER_SHIFT) > > > /** > > > diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h > > > index 1ebb88e7c184..1a0bdaee2f32 100644 > > > --- a/include/linux/pci-ats.h > > > +++ b/include/linux/pci-ats.h > > > @@ -40,7 +40,6 @@ void pci_disable_pasid(struct pci_dev *pdev); > > > void pci_restore_pasid_state(struct pci_dev *pdev); > > > int pci_pasid_features(struct pci_dev *pdev); > > > int pci_max_pasids(struct pci_dev *pdev); > > > -int pci_prg_resp_pasid_required(struct pci_dev *pdev); > > > #else /* CONFIG_PCI_PASID */ > > > @@ -67,11 +66,18 @@ static inline int pci_max_pasids(struct pci_dev *pdev) > > > return -EINVAL; > > > } > > > +#endif /* CONFIG_PCI_PASID */ > > > + > > > +#if defined(CONFIG_PCI_PRI) && defined(CONFIG_PCI_PASID) > > > + > > > +int pci_prg_resp_pasid_required(struct pci_dev *pdev); > > > + > > > +#else /* CONFIG_PCI_PASID && CONFIG_PCI_PRI */ > > > + > > > static inline int pci_prg_resp_pasid_required(struct pci_dev *pdev) > > > { > > > return 0; > > > } > > > -#endif /* CONFIG_PCI_PASID */ > > > - > > > +#endif > > > #endif /* LINUX_PCI_ATS_H*/ > > > -- > > > 2.21.0 > > > > -- > Sathyanarayanan Kuppuswamy > Linux kernel developer >