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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, FAKE_REPLY_C,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,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 37213C32771 for ; Wed, 22 Jan 2020 21:13:06 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EB84F24673 for ; Wed, 22 Jan 2020 21:13:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="hr15TIge" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB84F24673 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id A4A5086239; Wed, 22 Jan 2020 21:13:05 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ar704Dt5t7H6; Wed, 22 Jan 2020 21:13:05 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 064BC86234; Wed, 22 Jan 2020 21:13:04 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id DE450C1796; Wed, 22 Jan 2020 21:13:04 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 5D0B1C0174 for ; Wed, 22 Jan 2020 21:13:03 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 46EAF86239 for ; Wed, 22 Jan 2020 21:13:03 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eAEoYnco9MCa for ; Wed, 22 Jan 2020 21:13:02 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 1B2CB86234 for ; Wed, 22 Jan 2020 21:13:02 +0000 (UTC) Received: from localhost (mobile-166-175-186-165.mycingular.net [166.175.186.165]) (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 62EC52465B; Wed, 22 Jan 2020 21:13:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579727581; bh=fFweYeenFvs4HkuADNdVlhMAmdzgO7l02edUze2SN3M=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=hr15TIgenBSUenmaLItA1B+GdJ/AEhGWjr6P+Sgz4A9BmG6msd+dAgWMMi0bablaF qQ1XQE8RAWxBNy9t89QA0PGBgOppc6DhSiqxQNVVsJjUGoJMK7MDVTK5BNg3W68hmS a94emKuOhZI2Me8cFNwwFUbeLsSBMfMHUZdg+mAI= Date: Wed, 22 Jan 2020 15:12:59 -0600 From: Bjorn Helgaas To: Jon Derrick Subject: Re: [PATCH v5 3/7] PCI: Introduce pci_real_dma_dev() Message-ID: <20200122211259.GA19172@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1579613871-301529-4-git-send-email-jonathan.derrick@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Cc: linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org, Keith Busch , David Woodhouse , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, Jan 21, 2020 at 06:37:47AM -0700, Jon Derrick wrote: > The current DMA alias implementation requires the aliased device be on > the same PCI bus as the requester ID. This introduces an arch-specific > mechanism to point to another PCI device when doing mapping and > PCI DMA alias search. The default case returns the actual device. > > CC: Christoph Hellwig > Signed-off-by: Jon Derrick Acked-by: Bjorn Helgaas Looks like a nice cleanup to me. Lorenzo, let me know if you want me to take this. > --- > arch/x86/pci/common.c | 10 ++++++++++ > drivers/pci/pci.c | 19 ++++++++++++++++++- > drivers/pci/search.c | 6 ++++++ > include/linux/pci.h | 1 + > 4 files changed, 35 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c > index 1e59df0..fe21a5c 100644 > --- a/arch/x86/pci/common.c > +++ b/arch/x86/pci/common.c > @@ -736,3 +736,13 @@ int pci_ext_cfg_avail(void) > else > return 0; > } > + > +#if IS_ENABLED(CONFIG_VMD) > +struct pci_dev *pci_real_dma_dev(struct pci_dev *dev) > +{ > + if (is_vmd(dev->bus)) > + return to_pci_sysdata(dev->bus)->vmd_dev; > + > + return dev; > +} > +#endif > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 581b177..36d24f2 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -6048,7 +6048,9 @@ bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2) > return (dev1->dma_alias_mask && > test_bit(dev2->devfn, dev1->dma_alias_mask)) || > (dev2->dma_alias_mask && > - test_bit(dev1->devfn, dev2->dma_alias_mask)); > + test_bit(dev1->devfn, dev2->dma_alias_mask)) || > + pci_real_dma_dev(dev1) == dev2 || > + pci_real_dma_dev(dev2) == dev1; > } > > bool pci_device_is_present(struct pci_dev *pdev) > @@ -6072,6 +6074,21 @@ void pci_ignore_hotplug(struct pci_dev *dev) > } > EXPORT_SYMBOL_GPL(pci_ignore_hotplug); > > +/** > + * pci_real_dma_dev - Get PCI DMA device for PCI device > + * @dev: the PCI device that may have a PCI DMA alias > + * > + * Permits the platform to provide architecture-specific functionality to > + * devices needing to alias DMA to another PCI device on another PCI bus. If > + * the PCI device is on the same bus, it is recommended to use > + * pci_add_dma_alias(). This is the default implementation. Architecture > + * implementations can override this. > + */ > +struct pci_dev __weak *pci_real_dma_dev(struct pci_dev *dev) > +{ > + return dev; > +} > + > resource_size_t __weak pcibios_default_alignment(void) > { > return 0; > diff --git a/drivers/pci/search.c b/drivers/pci/search.c > index e4dbdef..2061672 100644 > --- a/drivers/pci/search.c > +++ b/drivers/pci/search.c > @@ -32,6 +32,12 @@ int pci_for_each_dma_alias(struct pci_dev *pdev, > struct pci_bus *bus; > int ret; > > + /* > + * The device may have an explicit alias requester ID for DMA where the > + * requester is on another PCI bus. > + */ > + pdev = pci_real_dma_dev(pdev); > ret = fn(pdev, pci_dev_id(pdev), data); > if (ret) > return ret; > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 930fab2..3840a54 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1202,6 +1202,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, > int pci_select_bars(struct pci_dev *dev, unsigned long flags); > bool pci_device_is_present(struct pci_dev *pdev); > void pci_ignore_hotplug(struct pci_dev *dev); > +struct pci_dev *pci_real_dma_dev(struct pci_dev *dev); > > int __printf(6, 7) pci_request_irq(struct pci_dev *dev, unsigned int nr, > irq_handler_t handler, irq_handler_t thread_fn, void *dev_id, > -- > 1.8.3.1 > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu