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Commit 0ec67667 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
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[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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 509cb37e

arch/s390/kernel/smp.c

+9 −6
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ static void smp_ext_bitcall(int, ec_bit_sig); 
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 @@ int smp_call_function (void (*func) (void *info), void *info, int nonatomic, 
 * 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 @@ int smp_call_function (void (*func) (void *info), void *info, int nonatomic, 
	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 @@ int smp_call_function (void (*func) (void *info), void *info, int nonatomic, 
	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 @@ int smp_call_function (void (*func) (void *info), void *info, int nonatomic, 
	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 @@ int smp_call_function_on(void (*func) (void *info), void *info, 
	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();