From patchwork Tue Aug 10 09:07:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: thermal-bot for Julien Panis X-Patchwork-Id: 495134 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=-20.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED 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 35904C432BE for ; Tue, 10 Aug 2021 09:08:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1DAEC61058 for ; Tue, 10 Aug 2021 09:08:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238727AbhHJJIU (ORCPT ); Tue, 10 Aug 2021 05:08:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238676AbhHJJIP (ORCPT ); Tue, 10 Aug 2021 05:08:15 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB20CC0613D3; Tue, 10 Aug 2021 02:07:52 -0700 (PDT) Date: Tue, 10 Aug 2021 09:07:47 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1628586467; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n5lxTLaZbsqU9+Yhln4Ijh0kHaWboFskcRp3znU4cXU=; b=rkbW51NiW255usKFyBYDfAX6Zbp4mT7sN/3/K/C0eUblDl0XV+FHjQscbETOZ+YJcg6UG6 WFe5KE/Tkt+WYBEuUK4HXzhL9aGPAJWARENxRUnK+I3c7LgYZXVbrF8xQxuuFU8rxXyn46 Cws6LPj6OBNFt50qcCey2HdKQYquBgeMPe2DY1n5ik/vaH47LnVTgRhXBqPFmPjXb1JLPO VbrvTgipto3TWDmQo87xosBv59k7p75Zw3vod0tnqv2kPIGC3qWTuSEM6FbjYrNe5h9bul RDS1qCMd0VmGGo/tpWrLIgjwsAahrZ7ZGYtKeCQNaFTlIZr/qNZ3TgGowN6u1w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1628586467; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=n5lxTLaZbsqU9+Yhln4Ijh0kHaWboFskcRp3znU4cXU=; b=6CpTWFHpQZ5JNzkzu0zC8FF4ACso6BTGcPCDuwg3ia4sFCo3jHWhGLU93lgC2L5Fbd6Jyj htOAOZkWitNrfWBw== From: "tip-bot2 for Thomas Gleixner" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: irq/core] PCI/MSI: Mask all unused MSI-X entries Cc: Thomas Gleixner , Marc Zyngier , Bjorn Helgaas , stable@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20210729222542.403833459@linutronix.de> References: <20210729222542.403833459@linutronix.de> MIME-Version: 1.0 Message-ID: <162858646718.395.12144785049690735295.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The following commit has been merged into the irq/core branch of tip: Commit-ID: 7d5ec3d3612396dc6d4b76366d20ab9fc06f399f Gitweb: https://git.kernel.org/tip/7d5ec3d3612396dc6d4b76366d20ab9fc06f399f Author: Thomas Gleixner AuthorDate: Thu, 29 Jul 2021 23:51:41 +02:00 Committer: Thomas Gleixner CommitterDate: Tue, 10 Aug 2021 10:59:20 +02:00 PCI/MSI: Mask all unused MSI-X entries When MSI-X is enabled the ordering of calls is: msix_map_region(); msix_setup_entries(); pci_msi_setup_msi_irqs(); msix_program_entries(); This has a few interesting issues: 1) msix_setup_entries() allocates the MSI descriptors and initializes them except for the msi_desc:masked member which is left zero initialized. 2) pci_msi_setup_msi_irqs() allocates the interrupt descriptors and sets up the MSI interrupts which ends up in pci_write_msi_msg() unless the interrupt chip provides its own irq_write_msi_msg() function. 3) msix_program_entries() does not do what the name suggests. It solely updates the entries array (if not NULL) and initializes the masked member for each MSI descriptor by reading the hardware state and then masks the entry. Obviously this has some issues: 1) The uninitialized masked member of msi_desc prevents the enforcement of masking the entry in pci_write_msi_msg() depending on the cached masked bit. Aside of that half initialized data is a NONO in general 2) msix_program_entries() only ensures that the actually allocated entries are masked. This is wrong as experimentation with crash testing and crash kernel kexec has shown. This limited testing unearthed that when the production kernel had more entries in use and unmasked when it crashed and the crash kernel allocated a smaller amount of entries, then a full scan of all entries found unmasked entries which were in use in the production kernel. This is obviously a device or emulation issue as the device reset should mask all MSI-X table entries, but obviously that's just part of the paper specification. Cure this by: 1) Masking all table entries in hardware 2) Initializing msi_desc::masked in msix_setup_entries() 3) Removing the mask dance in msix_program_entries() 4) Renaming msix_program_entries() to msix_update_entries() to reflect the purpose of that function. As the masking of unused entries has never been done the Fixes tag refers to a commit in: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Fixes: f036d4ea5fa7 ("[PATCH] ia32 Message Signalled Interrupt support") Signed-off-by: Thomas Gleixner Tested-by: Marc Zyngier Reviewed-by: Marc Zyngier Acked-by: Bjorn Helgaas Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.403833459@linutronix.de --- drivers/pci/msi.c | 45 +++++++++++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 18 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 5d39ed8..57c9ec9 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -691,6 +691,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, { struct irq_affinity_desc *curmsk, *masks = NULL; struct msi_desc *entry; + void __iomem *addr; int ret, i; int vec_count = pci_msix_vec_count(dev); @@ -711,6 +712,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, entry->msi_attrib.is_msix = 1; entry->msi_attrib.is_64 = 1; + if (entries) entry->msi_attrib.entry_nr = entries[i].entry; else @@ -722,6 +724,10 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, entry->msi_attrib.default_irq = dev->irq; entry->mask_base = base; + addr = pci_msix_desc_addr(entry); + if (addr) + entry->masked = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); + list_add_tail(&entry->list, dev_to_msi_list(&dev->dev)); if (masks) curmsk++; @@ -732,26 +738,25 @@ out: return ret; } -static void msix_program_entries(struct pci_dev *dev, - struct msix_entry *entries) +static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries) { struct msi_desc *entry; - int i = 0; - void __iomem *desc_addr; for_each_pci_msi_entry(entry, dev) { - if (entries) - entries[i++].vector = entry->irq; + if (entries) { + entries->vector = entry->irq; + entries++; + } + } +} - desc_addr = pci_msix_desc_addr(entry); - if (desc_addr) - entry->masked = readl(desc_addr + - PCI_MSIX_ENTRY_VECTOR_CTRL); - else - entry->masked = 0; +static void msix_mask_all(void __iomem *base, int tsize) +{ + u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT; + int i; - msix_mask_irq(entry, 1); - } + for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE) + writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL); } /** @@ -768,9 +773,9 @@ static void msix_program_entries(struct pci_dev *dev, static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, int nvec, struct irq_affinity *affd) { - int ret; - u16 control; void __iomem *base; + int ret, tsize; + u16 control; /* * Some devices require MSI-X to be enabled before the MSI-X @@ -782,12 +787,16 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); /* Request & Map MSI-X table region */ - base = msix_map_region(dev, msix_table_size(control)); + tsize = msix_table_size(control); + base = msix_map_region(dev, tsize); if (!base) { ret = -ENOMEM; goto out_disable; } + /* Ensure that all table entries are masked. */ + msix_mask_all(base, tsize); + ret = msix_setup_entries(dev, base, entries, nvec, affd); if (ret) goto out_disable; @@ -801,7 +810,7 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, if (ret) goto out_free; - msix_program_entries(dev, entries); + msix_update_entries(dev, entries); ret = populate_msi_sysfs(dev); if (ret)