arm64: Add support for hard lockup by using pmu counter

hulk inclusion
category: feature
bugzilla: 12805
CVE: NA
-------------------------------------------------

This patch is based on "arm64: perf: add nmi support for pmu" patch series.
This feature is alternative to the SDEI NMI watchdog. As we can not get
the cpu frequency, kernel cmdline parameter hardlockup_cpu_freq=xxx (in KHZ)
need to be passed by user currently. If it is not be passed, the perf NMI
watchdog will be disabled defaultly.
Signed-off-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm64/Kconfig

@@ -138,6 +138,7 @@ config ARM64
 	select HAVE_NMI
 	select HAVE_PATA_PLATFORM
 	select HAVE_PERF_EVENTS
+	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_REGS_AND_STACK_ACCESS_API
@@ -1201,6 +1202,7 @@ config ARM64_MODULE_PLTS
 config ARM64_PSEUDO_NMI
 	bool "Support for NMI-like interrupts"
 	select CONFIG_ARM_GIC_V3
+	select HAVE_PERF_EVENTS_NMI
 	help
 	  Adds support for mimicking Non-Maskable Interrupts through the use of
 	  GIC interrupt priority. This support requires version 3 or later of

arch/arm64/kernel/smp.c

@@ -1107,3 +1107,19 @@ void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 {
 	nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_nmi);
 }
+
+#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF
+u64 hardlockup_cpu_freq;
+
+static int __init hardlockup_cpu_freq_setup(char *str)
+{
+	hardlockup_cpu_freq = simple_strtoull(str, NULL, 0);
+	return 1;
+}
+__setup("hardlockup_cpu_freq=", hardlockup_cpu_freq_setup);
+
+u64 hw_nmi_get_sample_period(int watchdog_thresh)
+{
+	return hardlockup_cpu_freq * 1000 * watchdog_thresh;
+}
+#endif

kernel/watchdog_hld.c

@@ -186,6 +186,8 @@ static int hardlockup_detector_event_create(void)
 
 	wd_attr = &wd_hw_attr;
 	wd_attr->sample_period = hw_nmi_get_sample_period(watchdog_thresh);
+	if (!wd_attr->sample_period)
+		return -EINVAL;
 
 	/* Try to register using hardware perf events */
 	evt = perf_event_create_kernel_counter(wd_attr, cpu, NULL,

lib/Kconfig.debug

@@ -837,7 +837,7 @@ config HARDLOCKUP_DETECTOR_PERF
 
 config SDEI_WATCHDOG
 	bool "SDEI NMI Watchdog support"
-	depends on ARM_SDE_INTERFACE
+	depends on ARM_SDE_INTERFACE && !HAVE_HARDLOCKUP_DETECTOR_PERF
 	select HAVE_HARDLOCKUP_DETECTOR_ARCH
 	select HARDLOCKUP_CHECK_TIMESTAMP