Merge tag 'usb-ci-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter...

[sfrench/cifs-2.6.git] / arch / powerpc / kernel / watchdog.c

diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index b67f8b03a32d0f12ce29eeb4ac3be0a97384fe72..34721a257a770c450baac0288f8006c94ff1975b 100644 (file)
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -71,15 +71,20 @@ static inline void wd_smp_lock(unsigned long *flags)
         * This may be called from low level interrupt handlers at some
         * point in future.
         */
-       local_irq_save(*flags);
-       while (unlikely(test_and_set_bit_lock(0, &__wd_smp_lock)))
-               cpu_relax();
+       raw_local_irq_save(*flags);
+       hard_irq_disable(); /* Make it soft-NMI safe */
+       while (unlikely(test_and_set_bit_lock(0, &__wd_smp_lock))) {
+               raw_local_irq_restore(*flags);
+               spin_until_cond(!test_bit(0, &__wd_smp_lock));
+               raw_local_irq_save(*flags);
+               hard_irq_disable();
+       }
 }
 
 static inline void wd_smp_unlock(unsigned long *flags)
 {
        clear_bit_unlock(0, &__wd_smp_lock);
-       local_irq_restore(*flags);
+       raw_local_irq_restore(*flags);
 }
 
 static void wd_lockup_ipi(struct pt_regs *regs)
@@ -96,10 +101,10 @@ static void wd_lockup_ipi(struct pt_regs *regs)
                nmi_panic(regs, "Hard LOCKUP");
 }
 
-static void set_cpu_stuck(int cpu, u64 tb)
+static void set_cpumask_stuck(const struct cpumask *cpumask, u64 tb)
 {
-       cpumask_set_cpu(cpu, &wd_smp_cpus_stuck);
-       cpumask_clear_cpu(cpu, &wd_smp_cpus_pending);
+       cpumask_or(&wd_smp_cpus_stuck, &wd_smp_cpus_stuck, cpumask);
+       cpumask_andnot(&wd_smp_cpus_pending, &wd_smp_cpus_pending, cpumask);
        if (cpumask_empty(&wd_smp_cpus_pending)) {
                wd_smp_last_reset_tb = tb;
                cpumask_andnot(&wd_smp_cpus_pending,
@@ -107,6 +112,10 @@ static void set_cpu_stuck(int cpu, u64 tb)
                                &wd_smp_cpus_stuck);
        }
 }
+static void set_cpu_stuck(int cpu, u64 tb)
+{
+       set_cpumask_stuck(cpumask_of(cpu), tb);
+}
 
 static void watchdog_smp_panic(int cpu, u64 tb)
 {
@@ -135,11 +144,9 @@ static void watchdog_smp_panic(int cpu, u64 tb)
        }
        smp_flush_nmi_ipi(1000000);
 
-       /* Take the stuck CPU out of the watch group */
-       for_each_cpu(c, &wd_smp_cpus_pending)
-               set_cpu_stuck(c, tb);
+       /* Take the stuck CPUs out of the watch group */
+       set_cpumask_stuck(&wd_smp_cpus_pending, tb);
 
-out:
        wd_smp_unlock(&flags);
 
        printk_safe_flush();
@@ -152,6 +159,11 @@ out:
 
        if (hardlockup_panic)
                nmi_panic(NULL, "Hard LOCKUP");
+
+       return;
+
+out:
+       wd_smp_unlock(&flags);
 }
 
 static void wd_smp_clear_cpu_pending(int cpu, u64 tb)
@@ -258,9 +270,11 @@ static void wd_timer_fn(unsigned long data)
 
 void arch_touch_nmi_watchdog(void)
 {
+       unsigned long ticks = tb_ticks_per_usec * wd_timer_period_ms * 1000;
        int cpu = smp_processor_id();
 
-       watchdog_timer_interrupt(cpu);
+       if (get_tb() - per_cpu(wd_timer_tb, cpu) >= ticks)
+               watchdog_timer_interrupt(cpu);
 }
 EXPORT_SYMBOL(arch_touch_nmi_watchdog);
 
@@ -283,6 +297,8 @@ static void stop_watchdog_timer_on(unsigned int cpu)
 
 static int start_wd_on_cpu(unsigned int cpu)
 {
+       unsigned long flags;
+
        if (cpumask_test_cpu(cpu, &wd_cpus_enabled)) {
                WARN_ON(1);
                return 0;
@@ -297,12 +313,14 @@ static int start_wd_on_cpu(unsigned int cpu)
        if (!cpumask_test_cpu(cpu, &watchdog_cpumask))
                return 0;
 
+       wd_smp_lock(&flags);
        cpumask_set_cpu(cpu, &wd_cpus_enabled);
        if (cpumask_weight(&wd_cpus_enabled) == 1) {
                cpumask_set_cpu(cpu, &wd_smp_cpus_pending);
                wd_smp_last_reset_tb = get_tb();
        }
-       smp_wmb();
+       wd_smp_unlock(&flags);
+
        start_watchdog_timer_on(cpu);
 
        return 0;
@@ -310,12 +328,17 @@ static int start_wd_on_cpu(unsigned int cpu)
 
 static int stop_wd_on_cpu(unsigned int cpu)
 {
+       unsigned long flags;
+
        if (!cpumask_test_cpu(cpu, &wd_cpus_enabled))
                return 0; /* Can happen in CPU unplug case */
 
        stop_watchdog_timer_on(cpu);
 
+       wd_smp_lock(&flags);
        cpumask_clear_cpu(cpu, &wd_cpus_enabled);
+       wd_smp_unlock(&flags);
+
        wd_smp_clear_cpu_pending(cpu, get_tb());
 
        return 0;