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From: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@suse.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	Clemens Ladisch <clemens@ladisch.de>,
	Ricardo Neri <ricardo.neri@intel.com>,
	Stephane Eranian <eranian@google.com>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Ashok Raj <ashok.raj@intel.com>,
	x86@kernel.org, Andi Kleen <andi.kleen@intel.com>,
	"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
	Mimi Zohar <zohar@linux.ibm.com>, Tony Luck <tony.luck@intel.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	Philippe Ombredanne <pombredanne@nexb.com>,
	Nayna Jain <nayna@linux.ibm.com>
Subject: [RFC PATCH v4 16/21] x86/watchdog: Add a shim hardlockup detector
Date: Thu, 23 May 2019 18:16:18 -0700
Message-ID: <1558660583-28561-17-git-send-email-ricardo.neri-calderon@linux.intel.com> (raw)
In-Reply-To: <1558660583-28561-1-git-send-email-ricardo.neri-calderon@linux.intel.com>

The generic hardlockup detector is based on perf. It also provides a set
of weak stubs that CPU architectures can override. Add a shim hardlockup
detector for x86 that selects between perf and hpet implementations.

Specifically, this shim implementation is needed for the HPET-based
hardlockup detector; it can also be used for future implementations.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nayna Jain <nayna@linux.ibm.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: x86@kernel.org
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
---
 arch/x86/Kconfig.debug         |  4 ++
 arch/x86/kernel/Makefile       |  1 +
 arch/x86/kernel/watchdog_hld.c | 78 ++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 arch/x86/kernel/watchdog_hld.c

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 445bbb188f10..52c77e2145c9 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -169,11 +169,15 @@ config IOMMU_LEAK
 config HAVE_MMIOTRACE_SUPPORT
 	def_bool y
 
+config X86_HARDLOCKUP_DETECTOR
+	bool
+
 config X86_HARDLOCKUP_DETECTOR_HPET
 	bool "Use HPET Timer for Hard Lockup Detection"
 	select SOFTLOCKUP_DETECTOR
 	select HARDLOCKUP_DETECTOR
 	select HARDLOCKUP_DETECTOR_CORE
+	select X86_HARDLOCKUP_DETECTOR
 	depends on HPET_TIMER && HPET && X86_64
 	help
 	  Say y to enable a hardlockup detector that is driven by a High-
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 3ad55de67e8b..e60244b8a8ec 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_VM86)		+= vm86_32.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
 obj-$(CONFIG_HPET_TIMER) 	+= hpet.o
+obj-$(CONFIG_X86_HARDLOCKUP_DETECTOR) += watchdog_hld.o
 obj-$(CONFIG_X86_HARDLOCKUP_DETECTOR_HPET) += watchdog_hld_hpet.o
 obj-$(CONFIG_APB_TIMER)		+= apb_timer.o
 
diff --git a/arch/x86/kernel/watchdog_hld.c b/arch/x86/kernel/watchdog_hld.c
new file mode 100644
index 000000000000..c2512d4c79c5
--- /dev/null
+++ b/arch/x86/kernel/watchdog_hld.c
@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * A shim hardlockup detector. It overrides the weak stubs of the generic
+ * implementation to select between the perf- or the hpet-based implementation.
+ *
+ * Copyright (C) Intel Corporation 2019
+ */
+
+#include <linux/nmi.h>
+#include <asm/hpet.h>
+
+enum x86_hardlockup_detector {
+	X86_HARDLOCKUP_DETECTOR_PERF,
+	X86_HARDLOCKUP_DETECTOR_HPET,
+};
+
+static enum __read_mostly x86_hardlockup_detector detector_type;
+
+int watchdog_nmi_enable(unsigned int cpu)
+{
+	if (detector_type == X86_HARDLOCKUP_DETECTOR_PERF) {
+		hardlockup_detector_perf_enable();
+		return 0;
+	}
+
+	if (detector_type == X86_HARDLOCKUP_DETECTOR_HPET) {
+		hardlockup_detector_hpet_enable(cpu);
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+void watchdog_nmi_disable(unsigned int cpu)
+{
+	if (detector_type == X86_HARDLOCKUP_DETECTOR_PERF) {
+		hardlockup_detector_perf_disable();
+		return;
+	}
+
+	if (detector_type == X86_HARDLOCKUP_DETECTOR_HPET) {
+		hardlockup_detector_hpet_disable(cpu);
+		return;
+	}
+}
+
+int __init watchdog_nmi_probe(void)
+{
+	int ret;
+
+	/*
+	 * Try first with the HPET hardlockup detector. It will only
+	 * succeed if selected at build time and the nmi_watchdog
+	 * command-line parameter is configured. This ensure that the
+	 * perf-based detector is used by default, if selected at
+	 * build time.
+	 */
+	ret = hardlockup_detector_hpet_init();
+	if (!ret) {
+		detector_type = X86_HARDLOCKUP_DETECTOR_HPET;
+		return ret;
+	}
+
+	ret = hardlockup_detector_perf_init();
+	if (!ret) {
+		detector_type = X86_HARDLOCKUP_DETECTOR_PERF;
+		return ret;
+	}
+
+	return ret;
+}
+
+void watchdog_nmi_stop(void)
+{
+	/* Only the HPET lockup detector defines a stop function. */
+	if (detector_type == X86_HARDLOCKUP_DETECTOR_HPET)
+		hardlockup_detector_hpet_stop();
+}
-- 
2.17.1

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  parent reply index

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-24  1:16 [RFC PATCH v4 00/21] Implement an HPET-based " Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 01/21] x86/msi: Add definition for NMI delivery mode Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 02/21] x86/hpet: Expose hpet_writel() in header Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 03/21] x86/hpet: Calculate ticks-per-second in a separate function Ricardo Neri
2019-06-14 15:54   ` Thomas Gleixner
2019-06-14 15:59     ` Thomas Gleixner
2019-06-18 22:48     ` Ricardo Neri
2019-06-18 23:13       ` Thomas Gleixner
2019-05-24  1:16 ` [RFC PATCH v4 04/21] x86/hpet: Add hpet_set_comparator() for periodic and one-shot modes Ricardo Neri
2019-06-14 18:17   ` Thomas Gleixner
2019-06-18 22:48     ` Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 05/21] x86/hpet: Reserve timer for the HPET hardlockup detector Ricardo Neri
2019-06-11 19:54   ` Thomas Gleixner
2019-06-14  1:14     ` Ricardo Neri
2019-06-14 16:10       ` Thomas Gleixner
2019-06-18 22:48         ` Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 06/21] x86/hpet: Configure the timer used by the " Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 07/21] watchdog/hardlockup: Define a generic function to detect hardlockups Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 08/21] watchdog/hardlockup: Decouple the hardlockup detector from perf Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 09/21] x86/nmi: Add a NMI_WATCHDOG NMI handler category Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 10/21] watchdog/hardlockup: Add function to enable NMI watchdog on all allowed CPUs at once Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 11/21] x86/watchdog/hardlockup: Add an HPET-based hardlockup detector Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 12/21] watchdog/hardlockup/hpet: Adjust timer expiration on the number of monitored CPUs Ricardo Neri
2019-06-11 20:11   ` Thomas Gleixner
2019-06-18 22:46     ` Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 13/21] x86/watchdog/hardlockup/hpet: Determine if HPET timer caused NMI Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 14/21] watchdog/hardlockup: Use parse_option_str() to handle "nmi_watchdog" Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 15/21] watchdog/hardlockup/hpet: Only enable the HPET watchdog via a boot parameter Ricardo Neri
2019-05-24  1:16 ` Ricardo Neri [this message]
2019-05-24  1:16 ` [RFC PATCH v4 17/21] x86/tsc: Switch to perf-based hardlockup detector if TSC become unstable Ricardo Neri
2019-06-07  0:35   ` Stephane Eranian via iommu
2019-06-07 14:14     ` Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 18/21] x86/apic: Add a parameter for the APIC delivery mode Ricardo Neri
2019-06-16  9:55   ` Thomas Gleixner
2019-06-18 22:47     ` Ricardo Neri
2019-06-18 23:15       ` Thomas Gleixner
2019-05-24  1:16 ` [RFC PATCH v4 19/21] iommu/vt-d: Rework prepare_irte() to support per-irq " Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 20/21] iommu/vt-d: hpet: Reserve an interrupt remampping table entry for watchdog Ricardo Neri
2019-06-16 18:42   ` Thomas Gleixner
2019-06-16 19:21   ` Thomas Gleixner
2019-06-17  8:25     ` Thomas Gleixner
2019-06-17 21:38       ` Stephane Eranian via iommu
2019-06-17 23:08         ` Thomas Gleixner
2019-06-19 15:43           ` Jacob Pan
2019-06-21 15:33             ` Thomas Gleixner
2019-06-21 17:31               ` Jacob Pan
2019-06-21 18:39                 ` Jacob Pan
2019-06-21 20:05                   ` Thomas Gleixner
2019-06-21 23:55                     ` Ricardo Neri
2019-06-22  7:21                       ` Thomas Gleixner
2019-06-18 22:45       ` Ricardo Neri
2019-05-24  1:16 ` [RFC PATCH v4 21/21] x86/watchdog/hardlockup/hpet: Support interrupt remapping Ricardo Neri
2019-06-16  8:44   ` Thomas Gleixner
2019-06-16  8:53     ` Thomas Gleixner

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