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@changeidSigned-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>

arch/powerpc/include/asm/nmi.h

@@ -5,10 +5,10 @@
 #ifdef CONFIG_PPC_WATCHDOG
 extern void arch_touch_nmi_watchdog(void);
 long soft_nmi_interrupt(struct pt_regs *regs);
-void watchdog_nmi_set_timeout_pct(u64 pct);
+void watchdog_hardlockup_set_timeout_pct(u64 pct);
 #else
 static inline void arch_touch_nmi_watchdog(void) {}
-static inline void watchdog_nmi_set_timeout_pct(u64 pct) {}
+static inline void watchdog_hardlockup_set_timeout_pct(u64 pct) {}
 #endif
 
 #ifdef CONFIG_NMI_IPI

arch/powerpc/kernel/watchdog.c

@@ -438,7 +438,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer)
 {
 	int cpu = smp_processor_id();
 
-	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+	if (!(watchdog_enabled & WATCHDOG_HARDLOCKUP_ENABLED))
 		return HRTIMER_NORESTART;
 
 	if (!cpumask_test_cpu(cpu, &watchdog_cpumask))
@@ -479,7 +479,7 @@ static void start_watchdog(void *arg)
 		return;
 	}
 
-	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+	if (!(watchdog_enabled & WATCHDOG_HARDLOCKUP_ENABLED))
 		return;
 
 	if (!cpumask_test_cpu(cpu, &watchdog_cpumask))
@@ -546,7 +546,7 @@ static void watchdog_calc_timeouts(void)
 	wd_timer_period_ms = watchdog_thresh * 1000 * 2 / 5;
 }
 
-void watchdog_nmi_stop(void)
+void watchdog_hardlockup_stop(void)
 {
 	int cpu;
 
@@ -554,7 +554,7 @@ void watchdog_nmi_stop(void)
 		stop_watchdog_on_cpu(cpu);
 }
 
-void watchdog_nmi_start(void)
+void watchdog_hardlockup_start(void)
 {
 	int cpu;
 
@@ -566,7 +566,7 @@ void watchdog_nmi_start(void)
 /*
  * Invoked from core watchdog init.
  */
-int __init watchdog_nmi_probe(void)
+int __init watchdog_hardlockup_probe(void)
 {
 	int err;
 
@@ -582,7 +582,7 @@ int __init watchdog_nmi_probe(void)
 }
 
 #ifdef CONFIG_PPC_PSERIES
-void watchdog_nmi_set_timeout_pct(u64 pct)
+void watchdog_hardlockup_set_timeout_pct(u64 pct)
 {
 	pr_info("Set the NMI watchdog timeout factor to %llu%%\n", pct);
 	WRITE_ONCE(wd_timeout_pct, pct);

arch/powerpc/platforms/pseries/mobility.c

@@ -750,7 +750,7 @@ static int pseries_migrate_partition(u64 handle)
 		goto out;
 
 	if (factor)
-		watchdog_nmi_set_timeout_pct(factor);
+		watchdog_hardlockup_set_timeout_pct(factor);
 
 	ret = pseries_suspend(handle);
 	if (ret == 0) {
@@ -766,7 +766,7 @@ static int pseries_migrate_partition(u64 handle)
 		pseries_cancel_migration(handle, ret);
 
 	if (factor)
-		watchdog_nmi_set_timeout_pct(0);
+		watchdog_hardlockup_set_timeout_pct(0);
 
 out:
 	vas_migration_handler(VAS_RESUME);

arch/sparc/kernel/nmi.c

@@ -282,7 +282,7 @@ __setup("nmi_watchdog=", setup_nmi_watchdog);
  * sparc specific NMI watchdog enable function.
  * Enables watchdog if it is not enabled already.
  */
-void watchdog_nmi_enable(unsigned int cpu)
+void watchdog_hardlockup_enable(unsigned int cpu)
 {
 	if (atomic_read(&nmi_active) == -1) {
 		pr_warn("NMI watchdog cannot be enabled or disabled\n");
@@ -303,7 +303,7 @@ void watchdog_nmi_enable(unsigned int cpu)
  * sparc specific NMI watchdog disable function.
  * Disables watchdog if it is not disabled already.
  */
-void watchdog_nmi_disable(unsigned int cpu)
+void watchdog_hardlockup_disable(unsigned int cpu)
 {
 	if (atomic_read(&nmi_active) == -1)
 		pr_warn_once("NMI watchdog cannot be enabled or disabled\n");

include/linux/nmi.h

@@ -17,8 +17,6 @@ void lockup_detector_soft_poweroff(void);
 void lockup_detector_cleanup(void);
 
 extern int watchdog_user_enabled;
-extern int nmi_watchdog_user_enabled;
-extern int soft_watchdog_user_enabled;
 extern int watchdog_thresh;
 extern unsigned long watchdog_enabled;
 
@@ -68,17 +66,17 @@ static inline void reset_hung_task_detector(void) { }
  * 'watchdog_enabled' variable. Each lockup detector has its dedicated bit -
  * bit 0 for the hard lockup detector and bit 1 for the soft lockup detector.
  *
- * 'watchdog_user_enabled', 'nmi_watchdog_user_enabled' and
- * 'soft_watchdog_user_enabled' are variables that are only used as an
+ * 'watchdog_user_enabled', 'watchdog_hardlockup_user_enabled' and
+ * 'watchdog_softlockup_user_enabled' are variables that are only used as an
  * 'interface' between the parameters in /proc/sys/kernel and the internal
  * state bits in 'watchdog_enabled'. The 'watchdog_thresh' variable is
  * handled differently because its value is not boolean, and the lockup
  * detectors are 'suspended' while 'watchdog_thresh' is equal zero.
  */
-#define NMI_WATCHDOG_ENABLED_BIT   0
-#define SOFT_WATCHDOG_ENABLED_BIT  1
-#define NMI_WATCHDOG_ENABLED      (1 << NMI_WATCHDOG_ENABLED_BIT)
-#define SOFT_WATCHDOG_ENABLED     (1 << SOFT_WATCHDOG_ENABLED_BIT)
+#define WATCHDOG_HARDLOCKUP_ENABLED_BIT  0
+#define WATCHDOG_SOFTOCKUP_ENABLED_BIT   1
+#define WATCHDOG_HARDLOCKUP_ENABLED     (1 << WATCHDOG_HARDLOCKUP_ENABLED_BIT)
+#define WATCHDOG_SOFTOCKUP_ENABLED      (1 << WATCHDOG_SOFTOCKUP_ENABLED_BIT)
 
 #if defined(CONFIG_HARDLOCKUP_DETECTOR)
 extern void hardlockup_detector_disable(void);
@@ -120,11 +118,11 @@ static inline int hardlockup_detector_perf_init(void) { return 0; }
 # endif
 #endif
 
-void watchdog_nmi_stop(void);
-void watchdog_nmi_start(void);
-int watchdog_nmi_probe(void);
-void watchdog_nmi_enable(unsigned int cpu);
-void watchdog_nmi_disable(unsigned int cpu);
+void watchdog_hardlockup_stop(void);
+void watchdog_hardlockup_start(void);
+int watchdog_hardlockup_probe(void);
+void watchdog_hardlockup_enable(unsigned int cpu);
+void watchdog_hardlockup_disable(unsigned int cpu);
 
 void lockup_detector_reconfigure(void);
 

kernel/watchdog_perf.c

@@ -215,7 +215,7 @@ void __init hardlockup_detector_perf_restart(void)
 
 	lockdep_assert_cpus_held();
 
-	if (!(watchdog_enabled & NMI_WATCHDOG_ENABLED))
+	if (!(watchdog_enabled & WATCHDOG_HARDLOCKUP_ENABLED))
 		return;
 
 	for_each_online_cpu(cpu) {