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-rw-r--r--include/linux/irqdesc.h7
-rw-r--r--kernel/cpu.c22
-rw-r--r--kernel/irq/internals.h4
3 files changed, 27 insertions, 6 deletions
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h
index 624a668..fcea4e4 100644
--- a/include/linux/irqdesc.h
+++ b/include/linux/irqdesc.h
@@ -87,7 +87,12 @@ struct irq_desc {
const char *name;
} ____cacheline_internodealigned_in_smp;
-#ifndef CONFIG_SPARSE_IRQ
+#ifdef CONFIG_SPARSE_IRQ
+extern void irq_lock_sparse(void);
+extern void irq_unlock_sparse(void);
+#else
+static inline void irq_lock_sparse(void) { }
+static inline void irq_unlock_sparse(void) { }
extern struct irq_desc irq_desc[NR_IRQS];
#endif
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 9c9c9fa..6a37454 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -21,6 +21,7 @@
#include <linux/suspend.h>
#include <linux/lockdep.h>
#include <linux/tick.h>
+#include <linux/irq.h>
#include <trace/events/power.h>
#include "smpboot.h"
@@ -392,13 +393,19 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
smpboot_park_threads(cpu);
/*
- * So now all preempt/rcu users must observe !cpu_active().
+ * Prevent irq alloc/free while the dying cpu reorganizes the
+ * interrupt affinities.
*/
+ irq_lock_sparse();
+ /*
+ * So now all preempt/rcu users must observe !cpu_active().
+ */
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
+ irq_unlock_sparse();
goto out_release;
}
BUG_ON(cpu_online(cpu));
@@ -415,6 +422,9 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */
per_cpu(cpu_dead_idle, cpu) = false;
+ /* Interrupts are moved away from the dying cpu, reenable alloc/free */
+ irq_unlock_sparse();
+
hotplug_cpu__broadcast_tick_pull(cpu);
/* This actually kills the CPU. */
__cpu_die(cpu);
@@ -517,8 +527,18 @@ static int _cpu_up(unsigned int cpu, int tasks_frozen)
goto out_notify;
}
+ /*
+ * Some architectures have to walk the irq descriptors to
+ * setup the vector space for the cpu which comes online.
+ * Prevent irq alloc/free across the bringup.
+ */
+ irq_lock_sparse();
+
/* Arch-specific enabling code. */
ret = __cpu_up(cpu, idle);
+
+ irq_unlock_sparse();
+
if (ret != 0)
goto out_notify;
BUG_ON(!cpu_online(cpu));
diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 4834ee8..61008b8 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -76,12 +76,8 @@ extern void unmask_threaded_irq(struct irq_desc *desc);
#ifdef CONFIG_SPARSE_IRQ
static inline void irq_mark_irq(unsigned int irq) { }
-extern void irq_lock_sparse(void);
-extern void irq_unlock_sparse(void);
#else
extern void irq_mark_irq(unsigned int irq);
-static inline void irq_lock_sparse(void) { }
-static inline void irq_unlock_sparse(void) { }
#endif
extern void init_kstat_irqs(struct irq_desc *desc, int node, int nr);
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