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,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 72B9EC06513 for ; Wed, 3 Jul 2019 17:56:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 503842189E for ; Wed, 3 Jul 2019 17:56:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562176618; bh=5x9nYr/bGtljeo+8XgQwsEz86LG7/Qa1TONMqcKMLrY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=FO6XNcGKTHdR8wym5hk/QeJXMNhAb9zAaRHBF4Y5V4he9kF/CE9rTDlxaYDDsswUc WOxR7FpLw6aYv2KVkHFYB/5sjO9mlI1nBH+YwCseypCw5Of+y65HTUPMxToar9psZS OlRSeQP2Eh2QK2N6hZWag/JzErafvhSOESmYYc/I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727100AbfGCR45 (ORCPT ); Wed, 3 Jul 2019 13:56:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:54382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbfGCR44 (ORCPT ); Wed, 3 Jul 2019 13:56:56 -0400 Received: from localhost (173-25-83-245.client.mchsi.com [173.25.83.245]) (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 A9D752184C; Wed, 3 Jul 2019 17:56:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562176615; bh=5x9nYr/bGtljeo+8XgQwsEz86LG7/Qa1TONMqcKMLrY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SA8RPFrWCwm9msjhObImMtqTZdAN5oNTrvABGhRXT/ipfE+q9BkK9sOiE82WKFakY Ov2czFSZ62pGhHWnaKDWxfjfG99LMRHQRewYtS7WVBORQA78tJ04yQhn0WNyKyYEBL NyXflP/xQJtjvF8NiKQ9CYWZ8sHyALj0BwM5HReo= Date: Wed, 3 Jul 2019 12:56:54 -0500 From: Bjorn Helgaas To: sathyanarayanan.kuppuswamy@linux.intel.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, keith.busch@intel.com Subject: Re: [PATCH v3 1/7] PCI/ATS: Fix pci_prg_resp_pasid_required() dependency issues Message-ID: <20190703175654.GN128603@google.com> References: 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 20, 2019 at 01:38:42PM -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. This is likely just confusion on my part, but I don't understand what you're doing here. pci_prg_resp_pasid_required() does not actually *depend* on the CONFIG_PCI_PRI config symbol. It is currently compiled only if CONFIG_PCI_ATS=y (which controls compilation of the entire ats.c) and CONFIG_PCI_PASID=y (since it's within #ifdef CONFIG_PCI_PASID). pci_prg_resp_pasid_required() is called by attach_device() (amd_iommu.c), which is only compiled if CONFIG_AMD_IOMMU=y, and that selects PCI_PRI. It is also called by iommu_enable_dev_iotlb() (intel-iommu.c). That file is compiled if CONFIG_INTEL_IOMMU=y and the call itself is inside #ifdef CONFIG_INTEL_IOMMU_SVM. But I don't see the PCI_PRI connection here. If this is just to limit the visibility, say that. But I don't think that's really a good reason. The chain of config symbols seems a little too complicated. > Fixes: e5567f5f6762 ("PCI/ATS: Add pci_prg_resp_pasid_required() > interface.") > 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 97c08146534a..f9eeb7db0db3 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 >