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
  ...

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

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

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

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)

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);
 

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)

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);

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");