From patchwork Thu Jan 9 14:30:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jon Derrick X-Patchwork-Id: 1220641 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47tyWG03ylz9sPn for ; Fri, 10 Jan 2020 07:33:46 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728159AbgAIUdo (ORCPT ); Thu, 9 Jan 2020 15:33:44 -0500 Received: from mga01.intel.com ([192.55.52.88]:37112 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727738AbgAIUdn (ORCPT ); Thu, 9 Jan 2020 15:33:43 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Jan 2020 12:33:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,414,1571727600"; d="scan'208";a="396206715" Received: from unknown (HELO nsgsw-rhel7p6.lm.intel.com) ([10.232.116.226]) by orsmga005.jf.intel.com with ESMTP; 09 Jan 2020 12:33:42 -0800 From: Jon Derrick To: , Cc: Bjorn Helgaas , Lorenzo Pieralisi , Keith Busch , Joerg Roedel , Christoph Hellwig , David Woodhouse , Lu Baolu , Jon Derrick Subject: [PATCH v2 3/5] PCI: Introduce direct dma alias Date: Thu, 9 Jan 2020 07:30:54 -0700 Message-Id: <1578580256-3483-4-git-send-email-jonathan.derrick@intel.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1578580256-3483-1-git-send-email-jonathan.derrick@intel.com> References: <1578580256-3483-1-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 bus as the dma parent. This introduces an arch-specific mechanism to point to an arbitrary struct device when doing mapping and pci alias search. Signed-off-by: Jon Derrick --- arch/x86/pci/common.c | 7 +++++++ drivers/pci/pci.c | 17 ++++++++++++++++- drivers/pci/search.c | 9 +++++++++ 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..565cc17 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 device *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..e4269e9 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->dev) || + (pci_direct_dma_alias(dev2) == &dev1->dev); } bool pci_device_is_present(struct pci_dev *pdev) @@ -6058,6 +6060,19 @@ void pci_ignore_hotplug(struct pci_dev *dev) } EXPORT_SYMBOL_GPL(pci_ignore_hotplug); +/** + * pci_direct_dma_alias - Get dma alias for pci device + * @dev: the PCI device that may have a dma alias + * + * Permits the platform to provide architecture-specific functionality to + * devices needing to alias dma to another device. This is the default + * implementation. Architecture implementations can override this. + */ +struct device __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..6d61209 100644 --- a/drivers/pci/search.c +++ b/drivers/pci/search.c @@ -32,6 +32,15 @@ int pci_for_each_dma_alias(struct pci_dev *pdev, struct pci_bus *bus; int ret; + if (unlikely(pci_direct_dma_alias(pdev))) { + struct device *dev = pci_direct_dma_alias(pdev); + + if (dev_is_pci(dev)) + pdev = to_pci_dev(dev); + return fn(pdev, PCI_DEVID(pdev->bus->number, pdev->devfn), + data); + } + 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..82494d3 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 device *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,