From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
[S390] smp: disable preemption in smp_call_function/smp_call_function_on
Avoid sprinkling a _lot_ of preempt_disable/preempt_enable pairs.
This would be necessary for e.g. the iucv driver. Also this way we
are more consistent with other architectures which disable
preemption at least for smp_call_function.
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
arch/s390/kernel/smp.c | 15 ++++++++-------
1 files changed, 8 insertions(+), 7 deletions(-)
diff -urpN linux-2.6/arch/s390/kernel/smp.c linux-2.6-patched/arch/s390/kernel/smp.c
--- linux-2.6/arch/s390/kernel/smp.c 2007-03-05 22:51:29.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/smp.c 2007-03-05 22:51:48.000000000 +0100
@@ -94,10 +94,9 @@ static void __smp_call_function_map(void
int cpu, local = 0;
/*
- * Can deadlock when interrupts are disabled or if in wrong context,
- * caller must disable preemption
+ * Can deadlock when interrupts are disabled or if in wrong context.
*/
- WARN_ON(irqs_disabled() || in_irq() || preemptible());
+ WARN_ON(irqs_disabled() || in_irq());
/*
* Check for local function call. We have to have the same call order
@@ -152,17 +151,18 @@ out:
* Run a function on all other CPUs.
*
* You must not call this function with disabled interrupts or from a
- * hardware interrupt handler. Must be called with preemption disabled.
- * You may call it from a bottom half.
+ * hardware interrupt handler. You may call it from a bottom half.
*/
int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
int wait)
{
cpumask_t map;
+ preempt_disable();
map = cpu_online_map;
cpu_clear(smp_processor_id(), map);
__smp_call_function_map(func, info, nonatomic, wait, map);
+ preempt_enable();
return 0;
}
EXPORT_SYMBOL(smp_call_function);
@@ -178,16 +178,17 @@ EXPORT_SYMBOL(smp_call_function);
* Run a function on one processor.
*
* You must not call this function with disabled interrupts or from a
- * hardware interrupt handler. Must be called with preemption disabled.
- * You may call it from a bottom half.
+ * hardware interrupt handler. You may call it from a bottom half.
*/
int smp_call_function_on(void (*func) (void *info), void *info, int nonatomic,
int wait, int cpu)
{
cpumask_t map = CPU_MASK_NONE;
+ preempt_disable();
cpu_set(cpu, map);
__smp_call_function_map(func, info, nonatomic, wait, map);
+ preempt_enable();
return 0;
}
EXPORT_SYMBOL(smp_call_function_on);
-
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