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=-10.1 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,USER_AGENT_GIT autolearn=ham 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 F3EF7C433E1 for ; Thu, 18 Jun 2020 01:23:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEF1121927 for ; Thu, 18 Jun 2020 01:23:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592443425; bh=iplyPM27PcNRmVU8iO4tDZsu6oYuCl3PiRkC1vxjPIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HglzSE2xFDeXynsAB4474FrP+B+DepPidpYXCeQp4o6dVsKlOv4Mrn8/Ia8KmU//b 26q5yIZuxxNNIYRdArMGL2F8G3qjOIn0RzeK4xr4Tr7ecmPsapctAumxnif4WNQsb+ BoKMIOQ7fBhB4F4ae0CnJEyAr2ldsuKIe323GaME= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731050AbgFRBXo (ORCPT ); Wed, 17 Jun 2020 21:23:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:52426 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729532AbgFRBUS (ORCPT ); Wed, 17 Jun 2020 21:20:18 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D8B42206F1; Thu, 18 Jun 2020 01:20:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592443217; bh=iplyPM27PcNRmVU8iO4tDZsu6oYuCl3PiRkC1vxjPIc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UIkRj8qPUV0l7ume2DeHkVsweRoIQy1KeEN+f+xRKlfaBgqjaXcX685Da7hvpK4zE GQ1cYgZvQ4LM7bRxCPiNw7vjTQ6T4wZuOCS/MIzLqbhtMuF5pLLvbpN/XkV6/MokBQ AV7O6/nf/lI70MK1IwiGSCaQnDTzUdmy3YEkqS8g= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Bjorn Helgaas , Aditya Paluri , Sasha Levin , linux-pci@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 173/266] PCI/PTM: Inherit Switch Downstream Port PTM settings from Upstream Port Date: Wed, 17 Jun 2020 21:14:58 -0400 Message-Id: <20200618011631.604574-173-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200618011631.604574-1-sashal@kernel.org> References: <20200618011631.604574-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bjorn Helgaas [ Upstream commit 7b38fd9760f51cc83d80eed2cfbde8b5ead9e93a ] Except for Endpoints, we enable PTM at enumeration-time. Previously we did not account for the fact that Switch Downstream Ports are not permitted to have a PTM capability; their PTM behavior is controlled by the Upstream Port (PCIe r5.0, sec 7.9.16). Since Downstream Ports don't have a PTM capability, we did not mark them as "ptm_enabled", which meant that pci_enable_ptm() on an Endpoint failed because there was no PTM path to it. Mark Downstream Ports as "ptm_enabled" if their Upstream Port has PTM enabled. Fixes: eec097d43100 ("PCI: Add pci_enable_ptm() for drivers to enable PTM on endpoints") Reported-by: Aditya Paluri Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin --- drivers/pci/pcie/ptm.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/pci/pcie/ptm.c b/drivers/pci/pcie/ptm.c index 9361f3aa26ab..357a454cafa0 100644 --- a/drivers/pci/pcie/ptm.c +++ b/drivers/pci/pcie/ptm.c @@ -39,10 +39,6 @@ void pci_ptm_init(struct pci_dev *dev) if (!pci_is_pcie(dev)) return; - pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM); - if (!pos) - return; - /* * Enable PTM only on interior devices (root ports, switch ports, * etc.) on the assumption that it causes no link traffic until an @@ -52,6 +48,23 @@ void pci_ptm_init(struct pci_dev *dev) pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END)) return; + /* + * Switch Downstream Ports are not permitted to have a PTM + * capability; their PTM behavior is controlled by the Upstream + * Port (PCIe r5.0, sec 7.9.16). + */ + ups = pci_upstream_bridge(dev); + if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM && + ups && ups->ptm_enabled) { + dev->ptm_granularity = ups->ptm_granularity; + dev->ptm_enabled = 1; + return; + } + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_PTM); + if (!pos) + return; + pci_read_config_dword(dev, pos + PCI_PTM_CAP, &cap); local_clock = (cap & PCI_PTM_GRANULARITY_MASK) >> 8; @@ -61,7 +74,6 @@ void pci_ptm_init(struct pci_dev *dev) * the spec recommendation (PCIe r3.1, sec 7.32.3), select the * furthest upstream Time Source as the PTM Root. */ - ups = pci_upstream_bridge(dev); if (ups && ups->ptm_enabled) { ctrl = PCI_PTM_CTRL_ENABLE; if (ups->ptm_granularity == 0) -- 2.25.1