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
  ...

Author: torvalds

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

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>

arch/arm64/Kconfig

@@ -204,13 +204,16 @@ 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
 	select HAVE_KVM
 	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

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 */

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

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();
+}

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);

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
  */

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];
 
 /*

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 */