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Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c14
-rw-r--r--kernel/smp.c40
2 files changed, 48 insertions, 6 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 67a60076dd7..6ba0f1ecb21 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -414,6 +414,14 @@ int disable_nonboot_cpus(void)
return error;
}
+void __weak arch_enable_nonboot_cpus_begin(void)
+{
+}
+
+void __weak arch_enable_nonboot_cpus_end(void)
+{
+}
+
void __ref enable_nonboot_cpus(void)
{
int cpu, error;
@@ -425,6 +433,9 @@ void __ref enable_nonboot_cpus(void)
goto out;
printk("Enabling non-boot CPUs ...\n");
+
+ arch_enable_nonboot_cpus_begin();
+
for_each_cpu(cpu, frozen_cpus) {
error = _cpu_up(cpu, 1);
if (!error) {
@@ -433,6 +444,9 @@ void __ref enable_nonboot_cpus(void)
}
printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
}
+
+ arch_enable_nonboot_cpus_end();
+
cpumask_clear(frozen_cpus);
out:
cpu_maps_update_done();
diff --git a/kernel/smp.c b/kernel/smp.c
index 94188b8ecc3..8e218500ab1 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -177,6 +177,11 @@ void generic_smp_call_function_interrupt(void)
int cpu = get_cpu();
/*
+ * Shouldn't receive this interrupt on a cpu that is not yet online.
+ */
+ WARN_ON_ONCE(!cpu_online(cpu));
+
+ /*
* Ensure entry is visible on call_function_queue after we have
* entered the IPI. See comment in smp_call_function_many.
* If we don't have this, then we may miss an entry on the list
@@ -230,6 +235,11 @@ void generic_smp_call_function_single_interrupt(void)
unsigned int data_flags;
LIST_HEAD(list);
+ /*
+ * Shouldn't receive this interrupt on a cpu that is not yet online.
+ */
+ WARN_ON_ONCE(!cpu_online(smp_processor_id()));
+
spin_lock(&q->lock);
list_replace_init(&q->list, &list);
spin_unlock(&q->lock);
@@ -285,8 +295,14 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
*/
this_cpu = get_cpu();
- /* Can deadlock when called with interrupts disabled */
- WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
+ /*
+ * Can deadlock when called with interrupts disabled.
+ * We allow cpu's that are not yet online though, as no one else can
+ * send smp call function interrupt to this cpu and as such deadlocks
+ * can't happen.
+ */
+ WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
+ && !oops_in_progress);
if (cpu == this_cpu) {
local_irq_save(flags);
@@ -329,8 +345,14 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
{
csd_lock(data);
- /* Can deadlock when called with interrupts disabled */
- WARN_ON_ONCE(wait && irqs_disabled() && !oops_in_progress);
+ /*
+ * Can deadlock when called with interrupts disabled.
+ * We allow cpu's that are not yet online though, as no one else can
+ * send smp call function interrupt to this cpu and as such deadlocks
+ * can't happen.
+ */
+ WARN_ON_ONCE(cpu_online(smp_processor_id()) && wait && irqs_disabled()
+ && !oops_in_progress);
generic_exec_single(cpu, data, wait);
}
@@ -365,8 +387,14 @@ void smp_call_function_many(const struct cpumask *mask,
unsigned long flags;
int cpu, next_cpu, this_cpu = smp_processor_id();
- /* Can deadlock when called with interrupts disabled */
- WARN_ON_ONCE(irqs_disabled() && !oops_in_progress);
+ /*
+ * Can deadlock when called with interrupts disabled.
+ * We allow cpu's that are not yet online though, as no one else can
+ * send smp call function interrupt to this cpu and as such deadlocks
+ * can't happen.
+ */
+ WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled()
+ && !oops_in_progress);
/* So, what's a CPU they want? Ignoring this one. */
cpu = cpumask_first_and(mask, cpu_online_mask);