From patchwork Fri Jan 10 17:21:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jon Derrick X-Patchwork-Id: 11328593 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2BBC9139A for ; Fri, 10 Jan 2020 23:24:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 147E42084D for ; Fri, 10 Jan 2020 23:24:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727460AbgAJXYF (ORCPT ); Fri, 10 Jan 2020 18:24:05 -0500 Received: from mga09.intel.com ([134.134.136.24]:46412 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727442AbgAJXYF (ORCPT ); Fri, 10 Jan 2020 18:24:05 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 15:24:05 -0800 X-IronPort-AV: E=Sophos;i="5.69,418,1571727600"; d="scan'208";a="212412164" Received: from unknown (HELO nsgsw-rhel7p6.lm.intel.com) ([10.232.116.226]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 15:24:03 -0800 From: Jon Derrick To: , Cc: Bjorn Helgaas , Lorenzo Pieralisi , Keith Busch , Joerg Roedel , Christoph Hellwig , David Woodhouse , Lu Baolu , Jon Derrick Subject: [PATCH v3 3/5] PCI: Introduce pci_direct_dma_alias() Date: Fri, 10 Jan 2020 10:21:11 -0700 Message-Id: <1578676873-6206-4-git-send-email-jonathan.derrick@intel.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1578676873-6206-1-git-send-email-jonathan.derrick@intel.com> References: <1578676873-6206-1-git-send-email-jonathan.derrick@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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. Signed-off-by: Jon Derrick --- arch/x86/pci/common.c | 7 +++++++ drivers/pci/pci.c | 19 ++++++++++++++++++- drivers/pci/search.c | 7 +++++++ include/linux/pci.h | 1 + 4 files changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index 1e59df0..83334a5 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -736,3 +736,10 @@ int pci_ext_cfg_avail(void) else return 0; } + +#if IS_ENABLED(CONFIG_VMD) +struct pci_dev *pci_direct_dma_alias(struct pci_dev *dev) +{ + return to_pci_sysdata(dev->bus)->vmd_dev; +} +#endif diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index ad746d9..1362694 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -6034,7 +6034,9 @@ 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_direct_dma_alias(dev1) == dev2) || + (pci_direct_dma_alias(dev2) == dev1); } bool pci_device_is_present(struct pci_dev *pdev) @@ -6058,6 +6060,21 @@ void pci_ignore_hotplug(struct pci_dev *dev) } EXPORT_SYMBOL_GPL(pci_ignore_hotplug); +/** + * pci_direct_dma_alias - Get PCI DMA alias 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_direct_dma_alias(struct pci_dev *dev) +{ + return NULL; +} + resource_size_t __weak pcibios_default_alignment(void) { return 0; diff --git a/drivers/pci/search.c b/drivers/pci/search.c index bade140..12811b3 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -32,6 +32,13 @@ 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. + */ + if (unlikely(pci_direct_dma_alias(pdev))) + pdev = pci_direct_dma_alias(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 c393dff..cb6677b 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_direct_dma_alias(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,