watchdog/hardlockup: rename some "NMI watchdog" constants/function

Do a search and replace of:
- NMI_WATCHDOG_ENABLED => WATCHDOG_HARDLOCKUP_ENABLED
- SOFT_WATCHDOG_ENABLED => WATCHDOG_SOFTOCKUP_ENABLED
- watchdog_nmi_ => watchdog_hardlockup_
- nmi_watchdog_available => watchdog_hardlockup_available
- nmi_watchdog_user_enabled => watchdog_hardlockup_user_enabled
- soft_watchdog_user_enabled => watchdog_softlockup_user_enabled
- NMI_WATCHDOG_DEFAULT => WATCHDOG_HARDLOCKUP_DEFAULT

Then update a few comments near where names were changed.

This is specifically to make it less confusing when we want to introduce
the buddy hardlockup detector, which isn't using NMIs.  As part of this,
we sanitized a few names for consistency.

[trix@redhat.com: make variables static]
  Link: https://lkml.kernel.org/r/20230525162822.1.I0fb41d138d158c9230573eaa37dc56afa2fb14ee@changeid
Link: https://lkml.kernel.org/r/20230519101840.v5.12.I91f7277bab4bf8c0cb238732ed92e7ce7bbd71a6@changeid
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Colin Cross <ccross@android.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masayoshi Mizuma <msys.mizuma@gmail.com>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Tzung-Bi Shih <tzungbi@chromium.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 57 insertions, 56 deletions

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 64d7d2a0a7df..c6790c7dc08d 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -30,17 +30,17 @@
 static DEFINE_MUTEX(watchdog_mutex);
 
 #if defined(CONFIG_HARDLOCKUP_DETECTOR) || defined(CONFIG_HAVE_NMI_WATCHDOG)
-# define NMI_WATCHDOG_DEFAULT	1
+# define WATCHDOG_HARDLOCKUP_DEFAULT	1
 #else
-# define NMI_WATCHDOG_DEFAULT	0
+# define WATCHDOG_HARDLOCKUP_DEFAULT	0
 #endif
 
 unsigned long __read_mostly watchdog_enabled;
 int __read_mostly watchdog_user_enabled = 1;
-int __read_mostly nmi_watchdog_user_enabled = NMI_WATCHDOG_DEFAULT;
-int __read_mostly soft_watchdog_user_enabled = 1;
+static int __read_mostly watchdog_hardlockup_user_enabled = WATCHDOG_HARDLOCKUP_DEFAULT;
+static int __read_mostly watchdog_softlockup_user_enabled = 1;
 int __read_mostly watchdog_thresh = 10;
-static int __read_mostly nmi_watchdog_available;
+static int __read_mostly watchdog_hardlockup_available;
 
 struct cpumask watchdog_cpumask __read_mostly;
 unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);
@@ -66,7 +66,7 @@ unsigned int __read_mostly hardlockup_panic =
  */
 void __init hardlockup_detector_disable(void)
 {
-	nmi_watchdog_user_enabled = 0;
+	watchdog_hardlockup_user_enabled = 0;
 }
 
 static int __init hardlockup_panic_setup(char *str)
@@ -76,9 +76,9 @@ static int __init hardlockup_panic_setup(char *str)
 	else if (!strncmp(str, "nopanic", 7))
 		hardlockup_panic = 0;
 	else if (!strncmp(str, "0", 1))
-		nmi_watchdog_user_enabled = 0;
+		watchdog_hardlockup_user_enabled = 0;
 	else if (!strncmp(str, "1", 1))
-		nmi_watchdog_user_enabled = 1;
+		watchdog_hardlockup_user_enabled = 1;
 	return 1;
 }
 __setup("nmi_watchdog=", hardlockup_panic_setup);
@@ -190,40 +190,40 @@ static inline void watchdog_hardlockup_kick(void) { }
  * These functions can be overridden if an architecture implements its
  * own hardlockup detector.
  *
- * watchdog_nmi_enable/disable can be implemented to start and stop when
+ * watchdog_hardlockup_enable/disable can be implemented to start and stop when
  * softlockup watchdog start and stop. The arch must select the
  * SOFTLOCKUP_DETECTOR Kconfig.
  */
-void __weak watchdog_nmi_enable(unsigned int cpu)
+void __weak watchdog_hardlockup_enable(unsigned int cpu)
 {
 	hardlockup_detector_perf_enable();
 }
 
-void __weak watchdog_nmi_disable(unsigned int cpu)
+void __weak watchdog_hardlockup_disable(unsigned int cpu)
 {
 	hardlockup_detector_perf_disable();
 }
 
-/* Return 0, if a NMI watchdog is available. Error code otherwise */
-int __weak __init watchdog_nmi_probe(void)
+/* Return 0, if a hardlockup watchdog is available. Error code otherwise */
+int __weak __init watchdog_hardlockup_probe(void)
 {
 	return hardlockup_detector_perf_init();
 }
 
 /**
- * watchdog_nmi_stop - Stop the watchdog for reconfiguration
+ * watchdog_hardlockup_stop - Stop the watchdog for reconfiguration
  *
  * The reconfiguration steps are:
- * watchdog_nmi_stop();
+ * watchdog_hardlockup_stop();
  * update_variables();
- * watchdog_nmi_start();
+ * watchdog_hardlockup_start();
  */
-void __weak watchdog_nmi_stop(void) { }
+void __weak watchdog_hardlockup_stop(void) { }
 
 /**
- * watchdog_nmi_start - Start the watchdog after reconfiguration
+ * watchdog_hardlockup_start - Start the watchdog after reconfiguration
  *
- * Counterpart to watchdog_nmi_stop().
+ * Counterpart to watchdog_hardlockup_stop().
  *
  * The following variables have been updated in update_variables() and
  * contain the currently valid configuration:
@@ -231,23 +231,23 @@ void __weak watchdog_nmi_stop(void) { }
  * - watchdog_thresh
  * - watchdog_cpumask
  */
-void __weak watchdog_nmi_start(void) { }
+void __weak watchdog_hardlockup_start(void) { }
 
 /**
  * lockup_detector_update_enable - Update the sysctl enable bit
  *
- * Caller needs to make sure that the NMI/perf watchdogs are off, so this
- * can't race with watchdog_nmi_disable().
+ * Caller needs to make sure that the hard watchdogs are off, so this
+ * can't race with watchdog_hardlockup_disable().
  */
 static void lockup_detector_update_enable(void)
 {
 	watchdog_enabled = 0;
 	if (!watchdog_user_enabled)
 		return;
-	if (nmi_watchdog_available && nmi_watchdog_user_enabled)
-		watchdog_enabled |= NMI_WATCHDOG_ENABLED;
-	if (soft_watchdog_user_enabled)
-		watchdog_enabled |= SOFT_WATCHDOG_ENABLED;
+	if (watchdog_hardlockup_available && watchdog_hardlockup_user_enabled)
+		watchdog_enabled |= WATCHDOG_HARDLOCKUP_ENABLED;
+	if (watchdog_softlockup_user_enabled)
+		watchdog_enabled |= WATCHDOG_SOFTOCKUP_ENABLED;
 }
 
 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
@@ -288,7 +288,7 @@ __setup("nowatchdog", nowatchdog_setup);
 
 static int __init nosoftlockup_setup(char *str)
 {
-	soft_watchdog_user_enabled = 0;
+	watchdog_softlockup_user_enabled = 0;
 	return 1;
 }
 __setup("nosoftlockup", nosoftlockup_setup);
@@ -402,7 +402,7 @@ static int is_softlockup(unsigned long touch_ts,
 			 unsigned long period_ts,
 			 unsigned long now)
 {
-	if ((watchdog_enabled & SOFT_WATCHDOG_ENABLED) && watchdog_thresh){
+	if ((watchdog_enabled & WATCHDOG_SOFTOCKUP_ENABLED) && watchdog_thresh) {
 		/* Warn about unreasonable delays. */
 		if (time_after(now, period_ts + get_softlockup_thresh()))
 			return now - touch_ts;
@@ -537,7 +537,7 @@ static void watchdog_enable(unsigned int cpu)
 	complete(done);
 
 	/*
-	 * Start the timer first to prevent the NMI watchdog triggering
+	 * Start the timer first to prevent the hardlockup watchdog triggering
 	 * before the timer has a chance to fire.
 	 */
 	hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
@@ -547,9 +547,9 @@ static void watchdog_enable(unsigned int cpu)
 
 	/* Initialize timestamp */
 	update_touch_ts();
-	/* Enable the perf event */
-	if (watchdog_enabled & NMI_WATCHDOG_ENABLED)
-		watchdog_nmi_enable(cpu);
+	/* Enable the hardlockup detector */
+	if (watchdog_enabled & WATCHDOG_HARDLOCKUP_ENABLED)
+		watchdog_hardlockup_enable(cpu);
 }
 
 static void watchdog_disable(unsigned int cpu)
@@ -559,11 +559,11 @@ static void watchdog_disable(unsigned int cpu)
 	WARN_ON_ONCE(cpu != smp_processor_id());
 
 	/*
-	 * Disable the perf event first. That prevents that a large delay
-	 * between disabling the timer and disabling the perf event causes
-	 * the perf NMI to detect a false positive.
+	 * Disable the hardlockup detector first. That prevents that a large
+	 * delay between disabling the timer and disabling the hardlockup
+	 * detector causes a false positive.
 	 */
-	watchdog_nmi_disable(cpu);
+	watchdog_hardlockup_disable(cpu);
 	hrtimer_cancel(hrtimer);
 	wait_for_completion(this_cpu_ptr(&softlockup_completion));
 }
@@ -619,7 +619,7 @@ int lockup_detector_offline_cpu(unsigned int cpu)
 static void __lockup_detector_reconfigure(void)
 {
 	cpus_read_lock();
-	watchdog_nmi_stop();
+	watchdog_hardlockup_stop();
 
 	softlockup_stop_all();
 	set_sample_period();
@@ -627,7 +627,7 @@ static void __lockup_detector_reconfigure(void)
 	if (watchdog_enabled && watchdog_thresh)
 		softlockup_start_all();
 
-	watchdog_nmi_start();
+	watchdog_hardlockup_start();
 	cpus_read_unlock();
 	/*
 	 * Must be called outside the cpus locked section to prevent
@@ -668,9 +668,9 @@ static __init void lockup_detector_setup(void)
 static void __lockup_detector_reconfigure(void)
 {
 	cpus_read_lock();
-	watchdog_nmi_stop();
+	watchdog_hardlockup_stop();
 	lockup_detector_update_enable();
-	watchdog_nmi_start();
+	watchdog_hardlockup_start();
 	cpus_read_unlock();
 }
 void lockup_detector_reconfigure(void)
@@ -725,14 +725,14 @@ static void proc_watchdog_update(void)
 /*
  * common function for watchdog, nmi_watchdog and soft_watchdog parameter
  *
- * caller             | table->data points to      | 'which'
- * -------------------|----------------------------|--------------------------
- * proc_watchdog      | watchdog_user_enabled      | NMI_WATCHDOG_ENABLED |
- *                    |                            | SOFT_WATCHDOG_ENABLED
- * -------------------|----------------------------|--------------------------
- * proc_nmi_watchdog  | nmi_watchdog_user_enabled  | NMI_WATCHDOG_ENABLED
- * -------------------|----------------------------|--------------------------
- * proc_soft_watchdog | soft_watchdog_user_enabled | SOFT_WATCHDOG_ENABLED
+ * caller             | table->data points to            | 'which'
+ * -------------------|----------------------------------|-------------------------------
+ * proc_watchdog      | watchdog_user_enabled            | WATCHDOG_HARDLOCKUP_ENABLED |
+ *                    |                                  | WATCHDOG_SOFTOCKUP_ENABLED
+ * -------------------|----------------------------------|-------------------------------
+ * proc_nmi_watchdog  | watchdog_hardlockup_user_enabled | WATCHDOG_HARDLOCKUP_ENABLED
+ * -------------------|----------------------------------|-------------------------------
+ * proc_soft_watchdog | watchdog_softlockup_user_enabled | WATCHDOG_SOFTOCKUP_ENABLED
  */
 static int proc_watchdog_common(int which, struct ctl_table *table, int write,
 				void *buffer, size_t *lenp, loff_t *ppos)
@@ -764,7 +764,8 @@ static int proc_watchdog_common(int which, struct ctl_table *table, int write,
 int proc_watchdog(struct ctl_table *table, int write,
 		  void *buffer, size_t *lenp, loff_t *ppos)
 {
-	return proc_watchdog_common(NMI_WATCHDOG_ENABLED|SOFT_WATCHDOG_ENABLED,
+	return proc_watchdog_common(WATCHDOG_HARDLOCKUP_ENABLED |
+				    WATCHDOG_SOFTOCKUP_ENABLED,
 				    table, write, buffer, lenp, ppos);
 }
 
@@ -774,9 +775,9 @@ int proc_watchdog(struct ctl_table *table, int write,
 int proc_nmi_watchdog(struct ctl_table *table, int write,
 		      void *buffer, size_t *lenp, loff_t *ppos)
 {
-	if (!nmi_watchdog_available && write)
+	if (!watchdog_hardlockup_available && write)
 		return -ENOTSUPP;
-	return proc_watchdog_common(NMI_WATCHDOG_ENABLED,
+	return proc_watchdog_common(WATCHDOG_HARDLOCKUP_ENABLED,
 				    table, write, buffer, lenp, ppos);
 }
 
@@ -786,7 +787,7 @@ int proc_nmi_watchdog(struct ctl_table *table, int write,
 int proc_soft_watchdog(struct ctl_table *table, int write,
 			void *buffer, size_t *lenp, loff_t *ppos)
 {
-	return proc_watchdog_common(SOFT_WATCHDOG_ENABLED,
+	return proc_watchdog_common(WATCHDOG_SOFTOCKUP_ENABLED,
 				    table, write, buffer, lenp, ppos);
 }
 
@@ -854,7 +855,7 @@ static struct ctl_table watchdog_sysctls[] = {
 	},
 	{
 		.procname       = "nmi_watchdog",
-		.data		= &nmi_watchdog_user_enabled,
+		.data		= &watchdog_hardlockup_user_enabled,
 		.maxlen		= sizeof(int),
 		.mode		= NMI_WATCHDOG_SYSCTL_PERM,
 		.proc_handler   = proc_nmi_watchdog,
@@ -871,7 +872,7 @@ static struct ctl_table watchdog_sysctls[] = {
 #ifdef CONFIG_SOFTLOCKUP_DETECTOR
 	{
 		.procname       = "soft_watchdog",
-		.data		= &soft_watchdog_user_enabled,
+		.data		= &watchdog_softlockup_user_enabled,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler   = proc_soft_watchdog,
@@ -940,8 +941,8 @@ void __init lockup_detector_init(void)
 	cpumask_copy(&watchdog_cpumask,
 		     housekeeping_cpumask(HK_TYPE_TIMER));
 
-	if (!watchdog_nmi_probe())
-		nmi_watchdog_available = true;
+	if (!watchdog_hardlockup_probe())
+		watchdog_hardlockup_available = true;
 	lockup_detector_setup();
 	watchdog_sysctl_init();
 }