Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp hotplug updates from Thomas Gleixner:
 "This is the final round of converting the notifier mess to the state
  machine. The removal of the notifiers and the related infrastructure
  will happen around rc1, as there are conversions outstanding in other
  trees.

  The whole exercise removed about 2000 lines of code in total and in
  course of the conversion several dozen bugs got fixed. The new
  mechanism allows to test almost every hotplug step standalone, so
  usage sites can exercise all transitions extensively.

  There is more room for improvement, like integrating all the
  pointlessly different architecture mechanisms of synchronizing,
  setting cpus online etc into the core code"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  tracing/rb: Init the CPU mask on allocation
  soc/fsl/qbman: Convert to hotplug state machine
  soc/fsl/qbman: Convert to hotplug state machine
  zram: Convert to hotplug state machine
  KVM/PPC/Book3S HV: Convert to hotplug state machine
  arm64/cpuinfo: Convert to hotplug state machine
  arm64/cpuinfo: Make hotplug notifier symmetric
  mm/compaction: Convert to hotplug state machine
  iommu/vt-d: Convert to hotplug state machine
  mm/zswap: Convert pool to hotplug state machine
  mm/zswap: Convert dst-mem to hotplug state machine
  mm/zsmalloc: Convert to hotplug state machine
  mm/vmstat: Convert to hotplug state machine
  mm/vmstat: Avoid on each online CPU loops
  mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
  tracing/rb: Convert to hotplug state machine
  oprofile/nmi timer: Convert to hotplug state machine
  net/iucv: Use explicit clean up labels in iucv_init()
  x86/pci/amd-bus: Convert to hotplug state machine
  x86/oprofile/nmi: Convert to hotplug state machine
  ...

1 files changed, 15 insertions, 47 deletions

diff --git a/drivers/watchdog/octeon-wdt-main.c b/drivers/watchdog/octeon-wdt-main.c
index b55981f88a08..529182d7d8a7 100644
--- a/drivers/watchdog/octeon-wdt-main.c
+++ b/drivers/watchdog/octeon-wdt-main.c
@@ -374,7 +374,7 @@ void octeon_wdt_nmi_stage3(u64 reg[32])
 	octeon_wdt_write_string("*** Chip soft reset soon ***\r\n");
 }
 
-static void octeon_wdt_disable_interrupt(int cpu)
+static int octeon_wdt_cpu_pre_down(unsigned int cpu)
 {
 	unsigned int core;
 	unsigned int irq;
@@ -392,9 +392,10 @@ static void octeon_wdt_disable_interrupt(int cpu)
 	cvmx_write_csr(CVMX_CIU_WDOGX(core), ciu_wdog.u64);
 
 	free_irq(irq, octeon_wdt_poke_irq);
+	return 0;
 }
 
-static void octeon_wdt_setup_interrupt(int cpu)
+static int octeon_wdt_cpu_online(unsigned int cpu)
 {
 	unsigned int core;
 	unsigned int irq;
@@ -424,25 +425,8 @@ static void octeon_wdt_setup_interrupt(int cpu)
 	ciu_wdog.s.len = timeout_cnt;
 	ciu_wdog.s.mode = 3;	/* 3 = Interrupt + NMI + Soft-Reset */
 	cvmx_write_csr(CVMX_CIU_WDOGX(core), ciu_wdog.u64);
-}
 
-static int octeon_wdt_cpu_callback(struct notifier_block *nfb,
-					   unsigned long action, void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-
-	switch (action & ~CPU_TASKS_FROZEN) {
-	case CPU_DOWN_PREPARE:
-		octeon_wdt_disable_interrupt(cpu);
-		break;
-	case CPU_ONLINE:
-	case CPU_DOWN_FAILED:
-		octeon_wdt_setup_interrupt(cpu);
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_OK;
+	return 0;
 }
 
 static int octeon_wdt_ping(struct watchdog_device __always_unused *wdog)
@@ -531,10 +515,6 @@ static int octeon_wdt_stop(struct watchdog_device *wdog)
 	return 0;
 }
 
-static struct notifier_block octeon_wdt_cpu_notifier = {
-	.notifier_call = octeon_wdt_cpu_callback,
-};
-
 static const struct watchdog_info octeon_wdt_info = {
 	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
 	.identity = "OCTEON",
@@ -553,6 +533,7 @@ static struct watchdog_device octeon_wdt = {
 	.ops	= &octeon_wdt_ops,
 };
 
+static enum cpuhp_state octeon_wdt_online;
 /**
  * Module/ driver initialization.
  *
@@ -562,7 +543,6 @@ static int __init octeon_wdt_init(void)
 {
 	int i;
 	int ret;
-	int cpu;
 	u64 *ptr;
 
 	/*
@@ -610,14 +590,16 @@ static int __init octeon_wdt_init(void)
 
 	cpumask_clear(&irq_enabled_cpus);
 
-	cpu_notifier_register_begin();
-	for_each_online_cpu(cpu)
-		octeon_wdt_setup_interrupt(cpu);
-
-	__register_hotcpu_notifier(&octeon_wdt_cpu_notifier);
-	cpu_notifier_register_done();
-
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "watchdog/octeon:online",
+				octeon_wdt_cpu_online, octeon_wdt_cpu_pre_down);
+	if (ret < 0)
+		goto err;
+	octeon_wdt_online = ret;
 	return 0;
+err:
+	cvmx_write_csr(CVMX_MIO_BOOT_LOC_CFGX(0), 0);
+	watchdog_unregister_device(&octeon_wdt);
+	return ret;
 }
 
 /**
@@ -625,22 +607,8 @@ static int __init octeon_wdt_init(void)
  */
 static void __exit octeon_wdt_cleanup(void)
 {
-	int cpu;
-
 	watchdog_unregister_device(&octeon_wdt);
-
-	cpu_notifier_register_begin();
-	__unregister_hotcpu_notifier(&octeon_wdt_cpu_notifier);
-
-	for_each_online_cpu(cpu) {
-		int core = cpu2core(cpu);
-		/* Disable the watchdog */
-		cvmx_write_csr(CVMX_CIU_WDOGX(core), 0);
-		/* Free the interrupt handler */
-		free_irq(OCTEON_IRQ_WDOG0 + core, octeon_wdt_poke_irq);
-	}
-
-	cpu_notifier_register_done();
+	cpuhp_remove_state(octeon_wdt_online);
 
 	/*
 	 * Disable the boot-bus memory, the code it points to is soon