From patchwork Thu Nov 8 01:12:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauricio Faria de Oliveira X-Patchwork-Id: 994598 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42r4yg6vzxz9sCQ; Thu, 8 Nov 2018 12:12:43 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1gKYsB-0003Pl-Bq; Thu, 08 Nov 2018 01:12:39 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1gKYs9-0003PX-Po for kernel-team@lists.ubuntu.com; Thu, 08 Nov 2018 01:12:37 +0000 Received: from mail-qk1-f200.google.com ([209.85.222.200]) by youngberry.canonical.com with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1gKYs9-0007GE-Fv for kernel-team@lists.ubuntu.com; Thu, 08 Nov 2018 01:12:37 +0000 Received: by mail-qk1-f200.google.com with SMTP id h68so35012077qke.3 for ; Wed, 07 Nov 2018 17:12:37 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Tge14EdXI08Yf8O3JhEQ3KEWuBGJS+iwJr52gM2qkMU=; b=JloDI8KTZu16f//uI87vnRDdwqyHPTPvCN3gS+x0WU901YEOQf+GVULm8SQ0ujA5zF iYzaaFAA7HRolDRqGs/v13sWBTjtkqbABBMg+guo2uBuukLy7CbPCyW34mektdsSA5qv DvI4ROELQa30WY1/CqBcCSHr9z/ETG5iS0skRzLCmukxv3by9HBrboQ2txIOsCqPgPYl cbrUIraroXfnL5NAq7tdwih1lsM2wXqyhsNzkna4XjXBPdvXopkRGKx2R/aNd2k/HoUI pqqa6aWZXfVkZbGN3Rf1arpz+zPQpIGL45hSHwEVTy5CoK1Upp1pVnLRBE0+F518525i GDDQ== X-Gm-Message-State: AGRZ1gKfBlTYRMojunA1HEX2qGa/N3WrO8ZjJR6zEHcZRKNy6X8/LRtw uNICbfIhbZ1NxxKtaU4SZWit1pLtMu5svO6dLs8rZT1/+eWcu++nFm6EN5sRM0vhIufW96aG1iu lwuvmdee0Cj/Sus0FIdQL9GkJgxwLpee0LqTWaP+g8g== X-Received: by 2002:a37:4eca:: with SMTP id c193mr2386162qkb.37.1541639556499; Wed, 07 Nov 2018 17:12:36 -0800 (PST) X-Google-Smtp-Source: AJdET5fK4cbayKms/ZpcFx657ZMgOs+32n7usXWNtrkWGZAW7lwnn8Zzf3+c7gDLIfeNeSKlg/Fofw== X-Received: by 2002:a37:4eca:: with SMTP id c193mr2386150qkb.37.1541639556300; Wed, 07 Nov 2018 17:12:36 -0800 (PST) Received: from localhost.localdomain ([179.159.57.206]) by smtp.gmail.com with ESMTPSA id r67sm1949071qkr.28.2018.11.07.17.12.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 07 Nov 2018 17:12:35 -0800 (PST) From: Mauricio Faria de Oliveira To: kernel-team@lists.ubuntu.com Subject: [SRU X][PATCH 1/3] UBUNTU: SAUCE: x86/quirks: Scan all busses for early PCI quirks Date: Wed, 7 Nov 2018 23:12:18 -0200 Message-Id: <20181108011220.9643-2-mfo@canonical.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181108011220.9643-1-mfo@canonical.com> References: <20181108011220.9643-1-mfo@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gpiccoli@canonical.com MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: "Guilherme G. Piccoli" BugLink: https://bugs.launchpad.net/bugs/1797990 Recently was noticed in an HP GEN9 system that kdump couldn't succeed due to an irq storm coming from an Intel NIC, narrowed down to be lack of clearing the MSI/MSI-X enable bits during the kdump kernel boot. For that, we need an early quirk to manually turn off MSI/MSI-X for PCI devices - this was worked as an optional boot parameter in a subsequent patch. Problem is that in our test system, the Intel NICs were not present in any secondary bus under the first PCIe root complex, so they couldn't be reached by the recursion in check_dev_quirk(). Modern systems, specially with multi-processors and multiple NUMA nodes expose multiple root complexes, describing more than one PCI hierarchy domain. Currently the simple recursion present in the early-quirks code from x86 starts a descending recursion from bus 0000:00, and reach many other busses by navigating this hierarchy walking through the bridges. This is not enough in systems with more than one root complex/host bridge, since the recursion won't "traverse" to other root complexes by starting statically in 0000:00 (for more details, see [0]). This patch hence implements the full bus/device/function scan in early_quirks(), by checking all possible busses instead of using a recursion based on the first root bus or limiting the search scope to the first 32 busses (like it was done in the beginning [1]). [0] https://bugs.launchpad.net/bugs/1797990 [1] From historical perspective, early PCI scan dates back to BitKeeper, added by Andi Kleen's "[PATCH] APIC fixes for x86-64", on October/2003. It initially restricted the search to the first 32 busses and slots. Due to a potential bug found in Nvidia chipsets, the scan was changed to run only in the first root bus: see commit 8659c406ade3 ("x86: only scan the root bus in early PCI quirks") Finally, secondary busses reachable from the 1st bus were re-added back by: commit 850c321027c2 ("x86/quirks: Reintroduce scanning of secondary buses") Reported-by: Dan Streetman Signed-off-by: Guilherme G. Piccoli Signed-off-by: Mauricio Faria de Oliveira --- arch/x86/kernel/early-quirks.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index a257d6077d1b..318e6baca319 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -723,7 +723,6 @@ static int __init check_dev_quirk(int num, int slot, int func) u16 vendor; u16 device; u8 type; - u8 sec; int i; class = read_pci_config_16(num, slot, func, PCI_CLASS_DEVICE); @@ -752,11 +751,8 @@ static int __init check_dev_quirk(int num, int slot, int func) type = read_pci_config_byte(num, slot, func, PCI_HEADER_TYPE); - if ((type & 0x7f) == PCI_HEADER_TYPE_BRIDGE) { - sec = read_pci_config_byte(num, slot, func, PCI_SECONDARY_BUS); - if (sec > num) - early_pci_scan_bus(sec); - } + if ((type & 0x7f) == PCI_HEADER_TYPE_BRIDGE) + return -1; if (!(type & 0x80)) return -1; @@ -779,8 +775,11 @@ static void __init early_pci_scan_bus(int bus) void __init early_quirks(void) { + int bus; + if (!early_pci_allowed()) return; - early_pci_scan_bus(0); + for (bus = 0; bus < 256; bus++) + early_pci_scan_bus(bus); } From patchwork Thu Nov 8 01:12:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauricio Faria de Oliveira X-Patchwork-Id: 994599 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42r4yk52tFz9sDL; Thu, 8 Nov 2018 12:12:46 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1gKYsE-0003RQ-G6; Thu, 08 Nov 2018 01:12:42 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1gKYsC-0003QB-49 for kernel-team@lists.ubuntu.com; Thu, 08 Nov 2018 01:12:40 +0000 Received: from mail-qk1-f199.google.com ([209.85.222.199]) by youngberry.canonical.com with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1gKYsB-0007GV-Ox for kernel-team@lists.ubuntu.com; Thu, 08 Nov 2018 01:12:39 +0000 Received: by mail-qk1-f199.google.com with SMTP id s123-v6so34248095qkf.12 for ; Wed, 07 Nov 2018 17:12:39 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=9oKLOoEIjg7iv7/PVBkZEtRsSqH3xbfsZLy+t02ayEM=; b=YbW0DBRZBZvQuRzOIgNuBKAKTlu5lIQG3REDbrXIO1JhdMjkUmGiqLkmOBsVVCowXm Eqel5KtLx21kTIK8GqvWqTW6123ez7T7HLMlFa2dpQQjy9GvV+y/LNJe/v/RwWSnRy+H 0wqqO7AnMMuTNtcKEZnUJX2ltJWtC7ElV7fcPeuh4rrD/tFzo+zwmjzDPc6Dwv4NAJ00 sH9tIM6Qt39cEoYBQnGH+z4ff4H/E2lPdtZiQAuJkOAkoryZtnnnqUoK5Q0M+J+k4py+ dsoRlEc1NAJk4y5+A9KJKpLgs3ZarmbORp6a1CcaTFX4kW8kTRnwt4kdqvQ+NpZTr9MD uV0Q== X-Gm-Message-State: AGRZ1gJQ3fHOguPvePHBQ7vL8XT3/jvc0s3njaUgFWb9UAo3+YM7s5Lm SjmqBl1mGmDUkh/DIfZDumqaovXfnEvL25EMMFzPKtXdKUChXsdS96nvIjnniOTKMqD45WZph4W 64hc071MNcCnpljrTOzqIXvoEcGn5W7tgx2HiWjGgHw== X-Received: by 2002:a37:1745:: with SMTP id i66mr2383743qkh.125.1541639558484; Wed, 07 Nov 2018 17:12:38 -0800 (PST) X-Google-Smtp-Source: AJdET5elAQ8hq/YYnovMIc6Eh13JXM9IPB4Pu1eK92y7FjfpLbFiU5cLySA/z1Jgl692EJJHgGZZOA== X-Received: by 2002:a37:1745:: with SMTP id i66mr2383733qkh.125.1541639558285; Wed, 07 Nov 2018 17:12:38 -0800 (PST) Received: from localhost.localdomain ([179.159.57.206]) by smtp.gmail.com with ESMTPSA id r67sm1949071qkr.28.2018.11.07.17.12.36 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 07 Nov 2018 17:12:37 -0800 (PST) From: Mauricio Faria de Oliveira To: kernel-team@lists.ubuntu.com Subject: [SRU X][PATCH 2/3] UBUNTU: SAUCE: x86/PCI: Export find_cap() to be used in early PCI code Date: Wed, 7 Nov 2018 23:12:19 -0200 Message-Id: <20181108011220.9643-3-mfo@canonical.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181108011220.9643-1-mfo@canonical.com> References: <20181108011220.9643-1-mfo@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gpiccoli@canonical.com MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: "Guilherme G. Piccoli" BugLink: https://bugs.launchpad.net/bugs/1797990 This patch exports (and renames) the function find_cap() to be used in the early PCI quirk code, by the next patch. This is being moved out from AGP code to generic early-PCI code since it's not AGP-specific and can be used for any PCI device. No functional changes intended. Signed-off-by: Guilherme G. Piccoli Signed-off-by: Mauricio Faria de Oliveira --- arch/x86/include/asm/pci-direct.h | 1 + arch/x86/kernel/aperture_64.c | 30 ++---------------------------- arch/x86/pci/early.c | 25 +++++++++++++++++++++++++ 3 files changed, 28 insertions(+), 28 deletions(-) diff --git a/arch/x86/include/asm/pci-direct.h b/arch/x86/include/asm/pci-direct.h index b1e7a45d868a..c5a8edf2dc8b 100644 --- a/arch/x86/include/asm/pci-direct.h +++ b/arch/x86/include/asm/pci-direct.h @@ -9,6 +9,7 @@ extern u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset); extern u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset); extern u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset); +extern u32 pci_early_find_cap(int bus, int slot, int func, int cap); extern void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, u32 val); extern void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val); extern void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val); diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c index 6e85f713641d..cabb09540662 100644 --- a/arch/x86/kernel/aperture_64.c +++ b/arch/x86/kernel/aperture_64.c @@ -91,32 +91,6 @@ static u32 __init allocate_aperture(void) } -/* Find a PCI capability */ -static u32 __init find_cap(int bus, int slot, int func, int cap) -{ - int bytes; - u8 pos; - - if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) & - PCI_STATUS_CAP_LIST)) - return 0; - - pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST); - for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) { - u8 id; - - pos &= ~3; - id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID); - if (id == 0xff) - break; - if (id == cap) - return pos; - pos = read_pci_config_byte(bus, slot, func, - pos+PCI_CAP_LIST_NEXT); - } - return 0; -} - /* Read a standard AGPv3 bridge header */ static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order) { @@ -205,8 +179,8 @@ static u32 __init search_agp_bridge(u32 *order, int *valid_agp) case PCI_CLASS_BRIDGE_HOST: case PCI_CLASS_BRIDGE_OTHER: /* needed? */ /* AGP bridge? */ - cap = find_cap(bus, slot, func, - PCI_CAP_ID_AGP); + cap = pci_early_find_cap(bus, slot, + func, PCI_CAP_ID_AGP); if (!cap) break; *valid_agp = 1; diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c index d1067d539bee..354c50788aae 100644 --- a/arch/x86/pci/early.c +++ b/arch/x86/pci/early.c @@ -50,6 +50,31 @@ void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val) outw(val, 0xcfc + (offset&2)); } +u32 pci_early_find_cap(int bus, int slot, int func, int cap) +{ + int bytes; + u8 pos; + + if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) & + PCI_STATUS_CAP_LIST)) + return 0; + + pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST); + for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) { + u8 id; + + pos &= ~3; + id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID); + if (id == 0xff) + break; + if (id == cap) + return pos; + pos = read_pci_config_byte(bus, slot, func, + pos+PCI_CAP_LIST_NEXT); + } + return 0; +} + int early_pci_allowed(void) { return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) == From patchwork Thu Nov 8 01:12:20 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauricio Faria de Oliveira X-Patchwork-Id: 994600 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 42r4ym672tz9sDC; Thu, 8 Nov 2018 12:12:48 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1gKYsF-0003T1-VC; Thu, 08 Nov 2018 01:12:43 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1gKYsE-0003RC-6E for kernel-team@lists.ubuntu.com; Thu, 08 Nov 2018 01:12:42 +0000 Received: from mail-qk1-f198.google.com ([209.85.222.198]) by youngberry.canonical.com with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1gKYsD-0007Gu-S5 for kernel-team@lists.ubuntu.com; Thu, 08 Nov 2018 01:12:41 +0000 Received: by mail-qk1-f198.google.com with SMTP id n68so34299649qkn.8 for ; Wed, 07 Nov 2018 17:12:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=BtPGxcC+BAD43UUl9bdKrBjvr75RDrmh9FP73HiPa4M=; b=Ast9kb8//aFAhux0PFwVIzOJwwugLe0o4dBUxnI9x+T1hYszSOBkvVfJDVOTBakFl/ KSd53yPkc/je5+2cCabl7P4oMq2KXP0rulwVoInRHPhH+7NTwjXFwl7ejqeOmLKQHtrm du+Se66AtiI422kYEMm77HhnG1vuxH7BNZNl8bSGOIQIVEFouyv9vEQCDdi+DAO3nQa1 Qn4HcQSvVcLLfbnZx6QRtxmUtZhntHnOgsu9MirlW9I6UcFi/E+hoQL/l2yteIviT4Wm KJn+o1SIiaye7Gze9SiILn5Wsh2uZ67BEZ4PwgtlOlGICWH/uGXiYauqZNz65XvrtASw Ldyw== X-Gm-Message-State: AGRZ1gKR33DTIVunLZQ5K+/VxRt40KFMSDtepdBTVVK+F+drc5s54OOc TRk0XuGvbzlipHWrO+y3DIjbeFA1ZhOI20GRKUI7E/TO/lddF7jz38S2vfP9C3KwdlrcmxoT1ZH wp3lA6yvtaTEBPA2rn+Chd+xe0oBl2plUKwdux1XmAg== X-Received: by 2002:a0c:8425:: with SMTP id l34mr2556583qva.101.1541639560526; Wed, 07 Nov 2018 17:12:40 -0800 (PST) X-Google-Smtp-Source: AJdET5fbAYbG8628TFc9R5yRN1liFocgty6BFNuhBhVbztaNUvnvZ0y7A0/2kuPpZ6L1J5/h70Q6XQ== X-Received: by 2002:a0c:8425:: with SMTP id l34mr2556571qva.101.1541639560289; Wed, 07 Nov 2018 17:12:40 -0800 (PST) Received: from localhost.localdomain ([179.159.57.206]) by smtp.gmail.com with ESMTPSA id r67sm1949071qkr.28.2018.11.07.17.12.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 07 Nov 2018 17:12:39 -0800 (PST) From: Mauricio Faria de Oliveira To: kernel-team@lists.ubuntu.com Subject: [SRU X][PATCH 3/3] UBUNTU: SAUCE: x86/quirks: Add parameter to clear MSIs early on boot Date: Wed, 7 Nov 2018 23:12:20 -0200 Message-Id: <20181108011220.9643-4-mfo@canonical.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181108011220.9643-1-mfo@canonical.com> References: <20181108011220.9643-1-mfo@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gpiccoli@canonical.com MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: "Guilherme G. Piccoli" BugLink: https://bugs.launchpad.net/bugs/1797990 We observed a kdump failure in x86 that was narrowed down to MSI irq storm coming from a PCI network device. The bug manifests as a lack of progress in the boot process of kdump kernel, and a flood of kernel messages like: [...] [ 342.265294] do_IRQ: 0.155 No irq handler for vector [ 342.266916] do_IRQ: 0.155 No irq handler for vector [ 347.258422] do_IRQ: 14053260 callbacks suppressed [...] The root cause of the issue is that kexec process of the kdump kernel doesn't ensure PCI devices are reset or MSI capabilities are disabled, so a PCI adapter could produce a huge amount of irqs which would steal all the processing time for the CPU (specially since we usually restrict kdump kernel to use a single CPU only). This patch implements the kernel parameter "pci=clearmsi" to clear the MSI/MSI-X enable bits in the Message Control register for all PCI devices during early boot time, thus preventing potential issues in the kexec'ed kernel. PCI spec also supports/enforces this need (see PCI Local Bus spec sections 6.8.1.3 and 6.8.2.3). Suggested-by: Dan Streetman Suggested-by: Gavin Shan Signed-off-by: Guilherme G. Piccoli [mfo: backport to ubuntu-xenial: - different path for Documentation/.../kernel-parameters.txt - update context lines in pci-direct.h and early-quirks.c] Signed-off-by: Mauricio Faria de Oliveira --- Documentation/kernel-parameters.txt | 6 ++++++ arch/x86/include/asm/pci-direct.h | 1 + arch/x86/kernel/early-quirks.c | 32 +++++++++++++++++++++++++++++ arch/x86/pci/common.c | 4 ++++ 4 files changed, 43 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c8f9d0bbf949..71c4280f9509 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2872,6 +2872,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. nomsi [MSI] If the PCI_MSI kernel config parameter is enabled, this kernel boot option can be used to disable the use of MSI interrupts system-wide. + clearmsi [X86] Clears MSI/MSI-X enable bits early in boot + time in order to avoid issues like adapters + screaming irqs and preventing boot progress. + Also, it enforces the PCI Local Bus spec + rule that those bits should be 0 in system reset + events (useful for kexec/kdump cases). noioapicquirk [APIC] Disable all boot interrupt quirks. Safety option to keep boot IRQs enabled. This should never be necessary. diff --git a/arch/x86/include/asm/pci-direct.h b/arch/x86/include/asm/pci-direct.h index c5a8edf2dc8b..4af4c656a4cc 100644 --- a/arch/x86/include/asm/pci-direct.h +++ b/arch/x86/include/asm/pci-direct.h @@ -14,6 +14,7 @@ extern void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, u32 val); extern void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val); extern void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val); +extern unsigned int pci_early_clear_msi; extern int early_pci_allowed(void); extern unsigned int pci_early_dump_regs; diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index 318e6baca319..25a3eba6295c 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -27,6 +27,37 @@ #include #include +static void __init early_pci_clear_msi(int bus, int slot, int func) +{ + int pos; + u16 ctrl; + + if (likely(!pci_early_clear_msi)) + return; + + pr_info_once("Clearing MSI/MSI-X enable bits early in boot (quirk)\n"); + + pos = pci_early_find_cap(bus, slot, func, PCI_CAP_ID_MSI); + if (pos) { + ctrl = read_pci_config_16(bus, slot, func, pos + PCI_MSI_FLAGS); + ctrl &= ~PCI_MSI_FLAGS_ENABLE; + write_pci_config_16(bus, slot, func, pos + PCI_MSI_FLAGS, ctrl); + + /* Read again to flush previous write */ + ctrl = read_pci_config_16(bus, slot, func, pos + PCI_MSI_FLAGS); + } + + pos = pci_early_find_cap(bus, slot, func, PCI_CAP_ID_MSIX); + if (pos) { + ctrl = read_pci_config_16(bus, slot, func, pos + PCI_MSIX_FLAGS); + ctrl &= ~PCI_MSIX_FLAGS_ENABLE; + write_pci_config_16(bus, slot, func, pos + PCI_MSIX_FLAGS, ctrl); + + /* Read again to flush previous write */ + ctrl = read_pci_config_16(bus, slot, func, pos + PCI_MSIX_FLAGS); + } +} + #define dev_err(msg) pr_err("pci 0000:%02x:%02x.%d: %s", bus, slot, func, msg) static void __init fix_hypertransport_config(int num, int slot, int func) @@ -701,6 +732,7 @@ static struct chipset early_qrk[] __initdata = { PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet}, { PCI_VENDOR_ID_BROADCOM, 0x4331, PCI_CLASS_NETWORK_OTHER, PCI_ANY_ID, 0, apple_airport_reset}, + { PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, early_pci_clear_msi}, {} }; diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index 8fd6f44aee83..c049ccca03a5 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -35,6 +35,7 @@ int noioapicreroute = 1; #endif int pcibios_last_bus = -1; unsigned long pirq_table_addr; +unsigned int pci_early_clear_msi; const struct pci_raw_ops *__read_mostly raw_pci_ops; const struct pci_raw_ops *__read_mostly raw_pci_ext_ops; @@ -621,6 +622,9 @@ char *__init pcibios_setup(char *str) } else if (!strcmp(str, "skip_isa_align")) { pci_probe |= PCI_CAN_SKIP_ISA_ALIGN; return NULL; + } else if (!strcmp(str, "clearmsi")) { + pci_early_clear_msi = 1; + return NULL; } else if (!strcmp(str, "noioapicquirk")) { noioapicquirk = 1; return NULL;