[S390] smp_call_function/smp_call_function_on locking.
smp_call_function and smp_call_function_on share the same lock and
smp_call_function_on disables softirq's so it can be called from
softirq context as well. Hence smp_call_function muss disable
softirqs as well to avoid deadlocks.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 65b5232..83a4ea6 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -57,7 +57,7 @@
static void smp_ext_bitcall_others(ec_bit_sig);
/*
-5B * Structure and data for smp_call_function(). This is designed to minimise
+ * Structure and data for smp_call_function(). This is designed to minimise
* static memory requirements. It also looks cleaner.
*/
static DEFINE_SPINLOCK(call_lock);
@@ -104,7 +104,7 @@
* remote CPUs are nearly ready to execute <<func>> or are or have executed.
*
* You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
+ * hardware interrupt handler.
*/
{
struct call_data_struct data;
@@ -113,8 +113,8 @@
if (cpus <= 0)
return 0;
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
+ /* Can deadlock when interrupts are disabled or if in wrong context */
+ WARN_ON(irqs_disabled() || in_irq());
data.func = func;
data.info = info;
@@ -123,7 +123,7 @@
if (wait)
atomic_set(&data.finished, 0);
- spin_lock(&call_lock);
+ spin_lock_bh(&call_lock);
call_data = &data;
/* Send a message to all other CPUs and wait for them to respond */
smp_ext_bitcall_others(ec_call_function);
@@ -135,7 +135,7 @@
if (wait)
while (atomic_read(&data.finished) != cpus)
cpu_relax();
- spin_unlock(&call_lock);
+ spin_unlock_bh(&call_lock);
return 0;
}
@@ -159,6 +159,9 @@
if (!cpu_online(cpu))
return -EINVAL;
+ /* Can deadlock when interrupts are disabled or if in wrong context */
+ WARN_ON(irqs_disabled() || in_irq());
+
/* disable preemption for local function call */
curr_cpu = get_cpu();