From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752519AbeESQw7 (ORCPT ); Sat, 19 May 2018 12:52:59 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:50914 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752344AbeESQw4 (ORCPT ); Sat, 19 May 2018 12:52:56 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 936FB602B6 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=okaya@codeaurora.org From: Sinan Kaya To: linux-pci@vger.kernel.org, timur@codeaurora.org Cc: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , Bjorn Helgaas , linux-kernel@vger.kernel.org (open list) Subject: [PATCH] PCI: Do not enable PASID when End-to-End TLP is not supported Date: Sat, 19 May 2018 12:52:49 -0400 Message-Id: <1526748769-701-1-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org A PCIe endpoint carries the process address space identifier (PASID) in the TLP prefix as part of the memory read/write transaction. The address information in the TLP is relevant only for a given PASID context. A translation agent takes PASID value and the address information from the TLP to look up the physical address in the system. If a bridge drops the TLP prefix, the translation agent can resolve the address to an incorrect location and cause data corruption. Prevent this condition by requiring End-to-End TLP prefix to be supported on the entire data path between the endpoint and the root port. Signed-off-by: Sinan Kaya --- drivers/pci/ats.c | 16 ++++++++++++++++ include/uapi/linux/pci_regs.h | 1 + 2 files changed, 17 insertions(+) diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 89305b5..0bcded5 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -265,7 +265,9 @@ EXPORT_SYMBOL_GPL(pci_reset_pri); int pci_enable_pasid(struct pci_dev *pdev, int features) { u16 control, supported; + struct pci_dev *bridge; int pos; + u32 cap; if (WARN_ON(pdev->pasid_enabled)) return -EBUSY; @@ -274,6 +276,20 @@ int pci_enable_pasid(struct pci_dev *pdev, int features) if (!pos) return -EINVAL; + bridge = pci_upstream_bridge(pdev); + while (bridge) { + if (!pci_find_capability(bridge, PCI_CAP_ID_EXP)) + return -EINVAL; + + if (pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap)) + return -EINVAL; + + if (!(cap & PCI_EXP_DEVCAP2_E2ETLP)) + return -EINVAL; + + bridge = pci_upstream_bridge(bridge); + } + pci_read_config_word(pdev, pos + PCI_PASID_CAP, &supported); supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV; diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 103ba79..d91dea5 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -634,6 +634,7 @@ #define PCI_EXP_DEVCAP2_OBFF_MASK 0x000c0000 /* OBFF support mechanism */ #define PCI_EXP_DEVCAP2_OBFF_MSG 0x00040000 /* New message signaling */ #define PCI_EXP_DEVCAP2_OBFF_WAKE 0x00080000 /* Re-use WAKE# for OBFF */ +#define PCI_EXP_DEVCAP2_E2ETLP 0x00200000 /* End-to-End TLP Prefix */ #define PCI_EXP_DEVCTL2 40 /* Device Control 2 */ #define PCI_EXP_DEVCTL2_COMP_TIMEOUT 0x000f /* Completion Timeout Value */ #define PCI_EXP_DEVCTL2_COMP_TMOUT_DIS 0x0010 /* Completion Timeout Disable */ -- 2.7.4