Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...

34 files changed, 87 insertions, 79 deletions

diff --git a/arch/Kconfig b/arch/Kconfig
index d6a68656950e..aff2746c8af2 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -426,20 +426,14 @@ config HAVE_HARDLOCKUP_DETECTOR_PERF
 	  The arch chooses to use the generic perf-NMI-based hardlockup
 	  detector. Must define HAVE_PERF_EVENTS_NMI.
 
-config HAVE_NMI_WATCHDOG
-	depends on HAVE_NMI
-	bool
-	help
-	  The arch provides a low level NMI watchdog. It provides
-	  asm/nmi.h, and defines its own arch_touch_nmi_watchdog().
-
 config HAVE_HARDLOCKUP_DETECTOR_ARCH
 	bool
-	select HAVE_NMI_WATCHDOG
 	help
-	  The arch chooses to provide its own hardlockup detector, which is
-	  a superset of the HAVE_NMI_WATCHDOG. It also conforms to config
-	  interfaces and parameters provided by hardlockup detector subsystem.
+	  The arch provides its own hardlockup detector implementation instead
+	  of the generic ones.
+
+	  It uses the same command line parameters, and sysctl interface,
+	  as the generic hardlockup detectors.
 
 config HAVE_PERF_REGS
 	bool
diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
index a7c2337b0c7d..18605f1b3580 100644
--- a/arch/arm/include/asm/irq.h
+++ b/arch/arm/include/asm/irq.h
@@ -27,7 +27,6 @@ struct irqaction;
 struct pt_regs;
 
 void handle_IRQ(unsigned int, struct pt_regs *);
-void init_IRQ(void);
 
 #ifdef CONFIG_SMP
 #include <linux/cpumask.h>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index d91829189dd4..3ae5c03ded0e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -204,6 +204,8 @@ config ARM64
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_GCC_PLUGINS
+	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
+		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
 	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_TIME_ACCOUNTING
@@ -211,6 +213,7 @@ config ARM64
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_NMI
 	select HAVE_PERF_EVENTS
+	select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI
 	select HAVE_PERF_REGS
 	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_PREEMPT_DYNAMIC_KEY
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 848739c15de8..553d1bc559c6 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -55,10 +55,6 @@ struct thread_info {
 void arch_setup_new_exec(void);
 #define arch_setup_new_exec     arch_setup_new_exec
 
-void arch_release_task_struct(struct task_struct *tsk);
-int arch_dup_task_struct(struct task_struct *dst,
-				struct task_struct *src);
-
 #endif
 
 #define TIF_SIGPENDING		0	/* signal pending */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 3864a64e2b2b..d95b3d6b471a 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_KUSER_HELPERS)		+= kuser32.o
 obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace.o entry-ftrace.o
 obj-$(CONFIG_MODULES)			+= module.o module-plts.o
 obj-$(CONFIG_PERF_EVENTS)		+= perf_regs.o perf_callchain.o
+obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF)	+= watchdog_hld.o
 obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
 obj-$(CONFIG_CPU_PM)			+= sleep.o suspend.o
 obj-$(CONFIG_CPU_IDLE)			+= cpuidle.o
diff --git a/arch/arm64/kernel/watchdog_hld.c b/arch/arm64/kernel/watchdog_hld.c
new file mode 100644
index 000000000000..dcd25322127c
--- /dev/null
+++ b/arch/arm64/kernel/watchdog_hld.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/nmi.h>
+#include <linux/cpufreq.h>
+#include <linux/perf/arm_pmu.h>
+
+/*
+ * Safe maximum CPU frequency in case a particular platform doesn't implement
+ * cpufreq driver. Although, architecture doesn't put any restrictions on
+ * maximum frequency but 5 GHz seems to be safe maximum given the available
+ * Arm CPUs in the market which are clocked much less than 5 GHz. On the other
+ * hand, we can't make it much higher as it would lead to a large hard-lockup
+ * detection timeout on parts which are running slower (eg. 1GHz on
+ * Developerbox) and doesn't possess a cpufreq driver.
+ */
+#define SAFE_MAX_CPU_FREQ	5000000000UL // 5 GHz
+u64 hw_nmi_get_sample_period(int watchdog_thresh)
+{
+	unsigned int cpu = smp_processor_id();
+	unsigned long max_cpu_freq;
+
+	max_cpu_freq = cpufreq_get_hw_max_freq(cpu) * 1000UL;
+	if (!max_cpu_freq)
+		max_cpu_freq = SAFE_MAX_CPU_FREQ;
+
+	return (u64)max_cpu_freq * watchdog_thresh;
+}
+
+bool __init arch_perf_nmi_is_available(void)
+{
+	/*
+	 * hardlockup_detector_perf_init() will success even if Pseudo-NMI turns off,
+	 * however, the pmu interrupts will act like a normal interrupt instead of
+	 * NMI and the hardlockup detector would be broken.
+	 */
+	return arm_pmu_irq_is_nmi();
+}
diff --git a/arch/microblaze/include/asm/setup.h b/arch/microblaze/include/asm/setup.h
index a06cc1f97aa9..3657f5e78a3d 100644
--- a/arch/microblaze/include/asm/setup.h
+++ b/arch/microblaze/include/asm/setup.h
@@ -16,8 +16,6 @@ extern char *klimit;
 
 extern void mmu_reset(void);
 
-void time_init(void);
-void init_IRQ(void);
 void machine_early_init(const char *cmdline, unsigned int ram,
 		unsigned int fdt, unsigned int msr, unsigned int tlb0,
 		unsigned int tlb1);
diff --git a/arch/mips/include/asm/fw/cfe/cfe_api.h b/arch/mips/include/asm/fw/cfe/cfe_api.h
index 25df2f4deb31..b52a6a9c26f1 100644
--- a/arch/mips/include/asm/fw/cfe/cfe_api.h
+++ b/arch/mips/include/asm/fw/cfe/cfe_api.h
@@ -17,9 +17,6 @@
 #include <linux/types.h>
 #include <linux/string.h>
 
-typedef long intptr_t;
-
-
 /*
  * Constants
  */
diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 44f9824c1d8c..75abfa834ab7 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -19,7 +19,6 @@
 #define IRQ_STACK_SIZE			THREAD_SIZE
 #define IRQ_STACK_START			(IRQ_STACK_SIZE - 16)
 
-extern void __init init_IRQ(void);
 extern void *irq_stack[NR_CPUS];
 
 /*
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 6b6eaa485946..d0eb1bd19a13 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -271,7 +271,6 @@ void arch_send_call_function_single_ipi(int cpu)
 static void
 smp_cpu_init(int cpunum)
 {
-	extern void init_IRQ(void);    /* arch/parisc/kernel/irq.c */
 	extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */
 
 	/* Set modes and Enable floating point coprocessor */
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index bff5820b7cda..8eb6c5e9e4f8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -90,8 +90,7 @@ config NMI_IPI
 
 config PPC_WATCHDOG
 	bool
-	depends on HARDLOCKUP_DETECTOR
-	depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
+	depends on HARDLOCKUP_DETECTOR_ARCH
 	default y
 	help
 	  This is a placeholder when the powerpc hardlockup detector
@@ -240,7 +239,7 @@ config PPC
 	select HAVE_GCC_PLUGINS			if GCC_VERSION >= 50200   # plugin support on gcc <= 5.1 is buggy on PPC
 	select HAVE_GENERIC_VDSO
 	select HAVE_HARDLOCKUP_DETECTOR_ARCH	if PPC_BOOK3S_64 && SMP
-	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI && !HAVE_HARDLOCKUP_DETECTOR_ARCH
+	select HAVE_HARDLOCKUP_DETECTOR_PERF	if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
 	select HAVE_HW_BREAKPOINT		if PERF_EVENTS && (PPC_BOOK3S || PPC_8xx)
 	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_TIME_ACCOUNTING
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index deadd2149426..f257cacb49a9 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -50,9 +50,14 @@ extern void *hardirq_ctx[NR_CPUS];
 extern void *softirq_ctx[NR_CPUS];
 
 void __do_IRQ(struct pt_regs *regs);
-extern void __init init_IRQ(void);
 
 int irq_choose_cpu(const struct cpumask *mask);
 
+#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI)
+extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
+					   bool exclude_self);
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
+#endif
+
 #endif /* _ASM_IRQ_H */
 #endif /* __KERNEL__ */
diff --git a/arch/powerpc/include/asm/nmi.h b/arch/powerpc/include/asm/nmi.h
index c3c7adef74de..49a75340c3e0 100644
--- a/arch/powerpc/include/asm/nmi.h
+++ b/arch/powerpc/include/asm/nmi.h
@@ -3,18 +3,10 @@
 #define _ASM_NMI_H
 
 #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) {}
-#endif
-
-#ifdef CONFIG_NMI_IPI
-extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
-					   bool exclude_self);
-#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
+static inline void watchdog_hardlockup_set_timeout_pct(u64 pct) {}
 #endif
 
 extern void hv_nmi_check_nonrecoverable(struct pt_regs *regs);
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index dbcc4a793f0b..edb2dd1f53eb 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/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);
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 6f30113b5468..cd632ba9ebff 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/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);
diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h
index 43b9ebfbd943..8e10a94430a2 100644
--- a/arch/riscv/include/asm/irq.h
+++ b/arch/riscv/include/asm/irq.h
@@ -16,6 +16,4 @@ void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void));
 
 struct fwnode_handle *riscv_get_intc_hwnode(void);
 
-extern void __init init_IRQ(void);
-
 #endif /* _ASM_RISCV_IRQ_H */
diff --git a/arch/riscv/include/asm/timex.h b/arch/riscv/include/asm/timex.h
index d6a7428f6248..a06697846e69 100644
--- a/arch/riscv/include/asm/timex.h
+++ b/arch/riscv/include/asm/timex.h
@@ -88,6 +88,4 @@ static inline int read_current_timer(unsigned long *timer_val)
 	return 0;
 }
 
-extern void time_init(void);
-
 #endif /* _ASM_RISCV_TIMEX_H */
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index c7c97921ed8d..a674c7d25da5 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -52,9 +52,6 @@ struct thread_info {
 
 struct task_struct;
 
-void arch_release_task_struct(struct task_struct *tsk);
-int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
-
 void arch_setup_new_exec(void);
 #define arch_setup_new_exec arch_setup_new_exec
 
diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index 34674e38826b..9f41853f36b9 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -34,14 +34,12 @@ void kernel_stack_overflow(struct pt_regs * regs);
 void handle_signal32(struct ksignal *ksig, sigset_t *oldset,
 		     struct pt_regs *regs);
 
-void __init init_IRQ(void);
 void do_io_irq(struct pt_regs *regs);
 void do_ext_irq(struct pt_regs *regs);
 void do_restart(void *arg);
 void __init startup_init(void);
 void die(struct pt_regs *regs, const char *str);
 int setup_profiling_timer(unsigned int multiplier);
-void __init time_init(void);
 unsigned long prepare_ftrace_return(unsigned long parent, unsigned long sp, unsigned long ip);
 
 struct s390_mmap_arg_struct;
diff --git a/arch/sh/include/asm/irq.h b/arch/sh/include/asm/irq.h
index 1c4923502fd4..0f384b1f45ca 100644
--- a/arch/sh/include/asm/irq.h
+++ b/arch/sh/include/asm/irq.h
@@ -22,7 +22,6 @@ extern unsigned short *irq_mask_register;
 /*
  * PINT IRQs
  */
-void init_IRQ_pint(void);
 void make_imask_irq(unsigned int irq);
 
 static inline int generic_irq_demux(int irq)
diff --git a/arch/sh/include/asm/rtc.h b/arch/sh/include/asm/rtc.h
index 69dbae2949b0..7fe7002d1d50 100644
--- a/arch/sh/include/asm/rtc.h
+++ b/arch/sh/include/asm/rtc.h
@@ -2,8 +2,6 @@
 #ifndef _ASM_RTC_H
 #define _ASM_RTC_H
 
-void time_init(void);
-
 #define RTC_CAP_4_DIGIT_YEAR	(1 << 0)
 
 struct sh_rtc_platform_info {
diff --git a/arch/sh/include/asm/thread_info.h b/arch/sh/include/asm/thread_info.h
index 1400fbb8b423..9f19a682d315 100644
--- a/arch/sh/include/asm/thread_info.h
+++ b/arch/sh/include/asm/thread_info.h
@@ -84,9 +84,6 @@ static inline struct thread_info *current_thread_info(void)
 
 #define THREAD_SIZE_ORDER	(THREAD_SHIFT - PAGE_SHIFT)
 
-extern void arch_task_cache_init(void);
-extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
-extern void arch_release_task_struct(struct task_struct *tsk);
 extern void init_thread_xstate(void);
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 36fd488ccbfa..6197b87f2b3b 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -33,7 +33,7 @@ config SPARC
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select GENERIC_PCI_IOMAP
 	select HAS_IOPORT
-	select HAVE_NMI_WATCHDOG if SPARC64
+	select HAVE_HARDLOCKUP_DETECTOR_SPARC64 if SPARC64
 	select HAVE_CBPF_JIT if SPARC32
 	select HAVE_EBPF_JIT if SPARC64
 	select HAVE_DEBUG_BUGVERBOSE
diff --git a/arch/sparc/Kconfig.debug b/arch/sparc/Kconfig.debug
index 6b2bec1888b3..37e003665de6 100644
--- a/arch/sparc/Kconfig.debug
+++ b/arch/sparc/Kconfig.debug
@@ -14,3 +14,17 @@ config FRAME_POINTER
 	bool
 	depends on MCOUNT
 	default y
+
+config HAVE_HARDLOCKUP_DETECTOR_SPARC64
+	bool
+	depends on HAVE_NMI
+	select HARDLOCKUP_DETECTOR_SPARC64
+	help
+	  Sparc64 hardlockup detector is the last one developed before adding
+	  the common infrastructure for handling hardlockup detectors. It is
+	  always built. It does _not_ use the common command line parameters
+	  and sysctl interface, except for /proc/sys/kernel/nmi_watchdog.
+
+config HARDLOCKUP_DETECTOR_SPARC64
+	bool
+	depends on HAVE_HARDLOCKUP_DETECTOR_SPARC64
diff --git a/arch/sparc/include/asm/irq_32.h b/arch/sparc/include/asm/irq_32.h
index 43ec2609b811..6ee48321cbc2 100644
--- a/arch/sparc/include/asm/irq_32.h
+++ b/arch/sparc/include/asm/irq_32.h
@@ -17,7 +17,6 @@
 
 #define irq_canonicalize(irq)	(irq)
 
-void __init init_IRQ(void);
 void __init sun4d_init_sbi_irq(void);
 
 #define NO_IRQ		0xffffffff
diff --git a/arch/sparc/include/asm/irq_64.h b/arch/sparc/include/asm/irq_64.h
index 154df2cf19f4..b436029f1ced 100644
--- a/arch/sparc/include/asm/irq_64.h
+++ b/arch/sparc/include/asm/irq_64.h
@@ -61,7 +61,6 @@ void sun4u_destroy_msi(unsigned int irq);
 unsigned int irq_alloc(unsigned int dev_handle, unsigned int dev_ino);
 void irq_free(unsigned int irq);
 
-void __init init_IRQ(void);
 void fixup_irqs(void);
 
 static inline void set_softint(unsigned long bits)
diff --git a/arch/sparc/include/asm/nmi.h b/arch/sparc/include/asm/nmi.h
index 90ee7863d9fe..920dc23f443f 100644
--- a/arch/sparc/include/asm/nmi.h
+++ b/arch/sparc/include/asm/nmi.h
@@ -8,7 +8,6 @@ void nmi_adjust_hz(unsigned int new_hz);
 
 extern atomic_t nmi_active;
 
-void arch_touch_nmi_watchdog(void);
 void start_nmi_watchdog(void *unused);
 void stop_nmi_watchdog(void *unused);
 
diff --git a/arch/sparc/include/asm/timer_64.h b/arch/sparc/include/asm/timer_64.h
index dcfad4613e18..ffff52c8b760 100644
--- a/arch/sparc/include/asm/timer_64.h
+++ b/arch/sparc/include/asm/timer_64.h
@@ -34,7 +34,6 @@ extern struct sparc64_tick_ops *tick_ops;
 
 unsigned long sparc64_get_clock_tick(unsigned int cpu);
 void setup_sparc64_timer(void);
-void __init time_init(void);
 
 #define TICK_PRIV_BIT		BIT(63)
 #define TICKCMP_IRQ_BIT		BIT(63)
diff --git a/arch/sparc/kernel/kernel.h b/arch/sparc/kernel/kernel.h
index 9cd09a3ef35f..15da3c0597a5 100644
--- a/arch/sparc/kernel/kernel.h
+++ b/arch/sparc/kernel/kernel.h
@@ -91,7 +91,6 @@ extern int static_irq_count;
 extern spinlock_t irq_action_lock;
 
 void unexpected_irq(int irq, void *dev_id, struct pt_regs * regs);
-void init_IRQ(void);
 
 /* sun4m_irq.c */
 void sun4m_init_IRQ(void);
diff --git a/arch/sparc/kernel/nmi.c b/arch/sparc/kernel/nmi.c
index 060fff95a305..17cdfdbf1f3b 100644
--- a/arch/sparc/kernel/nmi.c
+++ b/arch/sparc/kernel/nmi.c
@@ -65,6 +65,11 @@ void arch_touch_nmi_watchdog(void)
 }
 EXPORT_SYMBOL(arch_touch_nmi_watchdog);
 
+int __init watchdog_hardlockup_probe(void)
+{
+	return 0;
+}
+
 static void die_nmi(const char *str, struct pt_regs *regs, int do_panic)
 {
 	int this_cpu = smp_processor_id();
@@ -282,11 +287,11 @@ __setup("nmi_watchdog=", setup_nmi_watchdog);
  * sparc specific NMI watchdog enable function.
  * Enables watchdog if it is not enabled already.
  */
-int 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");
-		return -1;
+		return;
 	}
 
 	/*
@@ -295,17 +300,15 @@ int watchdog_nmi_enable(unsigned int cpu)
 	 * process first.
 	 */
 	if (!nmi_init_done)
-		return 0;
+		return;
 
 	smp_call_function_single(cpu, start_nmi_watchdog, NULL, 1);
-
-	return 0;
 }
 /*
  * 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");
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index 768aa234cbb4..29e083b92813 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -40,8 +40,6 @@ extern void __handle_irq(struct irq_desc *desc, struct pt_regs *regs);
 
 extern void init_ISA_irqs(void);
 
-extern void __init init_IRQ(void);
-
 #ifdef CONFIG_X86_LOCAL_APIC
 void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
 				    bool exclude_self);
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index f1cccba52eb9..d63b02940747 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -232,9 +232,6 @@ static inline int arch_within_stack_frames(const void * const stack,
 			   current_thread_info()->status & TS_COMPAT)
 #endif
 
-extern void arch_task_cache_init(void);
-extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
-extern void arch_release_task_struct(struct task_struct *tsk);
 extern void arch_setup_new_exec(void);
 #define arch_setup_new_exec arch_setup_new_exec
 #endif	/* !__ASSEMBLY__ */
diff --git a/arch/x86/include/asm/time.h b/arch/x86/include/asm/time.h
index a53961c64a56..f360104ed172 100644
--- a/arch/x86/include/asm/time.h
+++ b/arch/x86/include/asm/time.h
@@ -6,7 +6,6 @@
 #include <asm/mc146818rtc.h>
 
 extern void hpet_time_init(void);
-extern void time_init(void);
 extern bool pit_timer_init(void);
 extern bool tsc_clocksource_watchdog_disabled(void);
 
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index dc1b03be43eb..594fce0ca744 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -32,7 +32,6 @@ extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns);
 
 extern void tsc_early_init(void);
 extern void tsc_init(void);
-extern unsigned long calibrate_delay_is_known(void);
 extern void mark_tsc_unstable(char *reason);
 extern int unsynchronized_tsc(void);
 extern int check_tsc_unstable(void);