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: "H. Peter Anvin" <hpa@zytor.com>, Ashok Raj <ashok.raj@intel.com>,
Andi Kleen <ak@linux.intel.com>, Tony Luck <tony.luck@intel.com>,
Nicholas Piggin <npiggin@gmail.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Stephane Eranian <eranian@google.com>,
Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Ricardo Neri <ricardo.neri@intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Ricardo Neri <ricardo.neri-calderon@linux.intel.com>,
Andi Kleen <andi.kleen@intel.com>
Subject: [RFC PATCH v5 14/16] x86/watchdog: Add a shim hardlockup detector
Date: Tue, 4 May 2021 12:05:24 -0700 [thread overview]
Message-ID: <20210504190526.22347-15-ricardo.neri-calderon@linux.intel.com> (raw)
In-Reply-To: <20210504190526.22347-1-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: Stephane Eranian <eranian@google.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>
---
Changes since v4:
* Use a switch to enable and disable the various available detectors.
(Andi)
Changes since v3:
* Fixed style in multi-line comment. (Randy Dunlap)
Changes since v2:
* Pass cpu number as argument to hardlockup_detector_[enable|disable].
(Thomas Gleixner)
Changes since v1:
* Introduced this patch: Added an x86-specific shim hardlockup
detector. (Nicholas Piggin)
---
arch/x86/Kconfig.debug | 4 ++
arch/x86/kernel/Makefile | 1 +
arch/x86/kernel/watchdog_hld.c | 80 ++++++++++++++++++++++++++++++++++
3 files changed, 85 insertions(+)
create mode 100644 arch/x86/kernel/watchdog_hld.c
diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 0731da557a6d..4cdac3f80e80 100644
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -117,9 +117,13 @@ config IOMMU_LEAK
config HAVE_MMIOTRACE_SUPPORT
def_bool y
+config X86_HARDLOCKUP_DETECTOR
+ bool
+
config X86_HARDLOCKUP_DETECTOR_HPET
bool "HPET Timer for Hard Lockup Detection"
select HARDLOCKUP_DETECTOR_CORE
+ select X86_HARDLOCKUP_DETECTOR
depends on HARDLOCKUP_DETECTOR && HPET_TIMER && HPET && (X86_64 || X86_32)
help
The hardlockup detector is driven by one counter of the Performance
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 5d1a90b23577..3303f10b3d0a 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -115,6 +115,7 @@ 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_AMD_NB) += amd_nb.o
diff --git a/arch/x86/kernel/watchdog_hld.c b/arch/x86/kernel/watchdog_hld.c
new file mode 100644
index 000000000000..8947a7644421
--- /dev/null
+++ b/arch/x86/kernel/watchdog_hld.c
@@ -0,0 +1,80 @@
+// 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 2021
+ */
+
+#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)
+{
+ int ret = 0;
+
+ switch (detector_type) {
+ case X86_HARDLOCKUP_DETECTOR_PERF:
+ hardlockup_detector_perf_enable();
+ break;
+ case X86_HARDLOCKUP_DETECTOR_HPET:
+ hardlockup_detector_hpet_enable(cpu);
+ break;
+ default:
+ ret = -ENODEV;
+ }
+
+ return ret;
+}
+
+void watchdog_nmi_disable(unsigned int cpu)
+{
+ switch (detector_type) {
+ case X86_HARDLOCKUP_DETECTOR_PERF:
+ hardlockup_detector_perf_disable();
+ break;
+ case X86_HARDLOCKUP_DETECTOR_HPET:
+ hardlockup_detector_hpet_disable(cpu);
+ break;
+ }
+}
+
+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
next prev parent reply other threads:[~2021-05-04 19:08 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-04 19:05 [RFC PATCH v5 00/16] x86: Implement an HPET-based hardlockup detector Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 01/16] x86/hpet: Expose hpet_writel() in header Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 02/16] x86/hpet: Add helper function hpet_set_comparator_periodic() Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 03/16] x86/hpet: Reserve an HPET channel for the hardlockup detector Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 04/16] watchdog/hardlockup: Define a generic function to detect hardlockups Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 05/16] watchdog/hardlockup: Decouple the hardlockup detector from perf Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 06/16] x86/nmi: Add an NMI_WATCHDOG NMI handler category Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 07/16] x86/watchdog/hardlockup: Add an HPET-based hardlockup detector Ricardo Neri
2021-05-04 20:53 ` Thomas Gleixner
2021-05-04 19:05 ` [RFC PATCH v5 08/16] x86/watchdog/hardlockup/hpet: Introduce a target_cpumask Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 09/16] watchdog/hardlockup/hpet: Group packages receiving IPIs when needed Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 10/16] watchdog/hardlockup/hpet: Adjust timer expiration on the number of monitored groups Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 11/16] x86/watchdog/hardlockup/hpet: Determine if HPET timer caused NMI Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 12/16] watchdog/hardlockup: Use parse_option_str() to handle "nmi_watchdog" Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 13/16] watchdog/hardlockup/hpet: Only enable the HPET watchdog via a boot parameter Ricardo Neri
2021-05-04 19:05 ` Ricardo Neri [this message]
2021-05-04 19:05 ` [RFC PATCH v5 15/16] watchdog: Expose lockup_detector_reconfigure() Ricardo Neri
2021-05-04 19:05 ` [RFC PATCH v5 16/16] x86/tsc: Switch to perf-based hardlockup detector if TSC become unstable Ricardo Neri
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