[POWERPC] Avoid pointless WARN_ON(irqs_disabled()) from panic codepath
> ------------[ cut here ]------------
> Badness at arch/powerpc/kernel/smp.c:202
comes when smp_call_function_map() has been called with irqs disabled,
which is illegal. However, there is a special case, the panic() codepath,
when we do not want to warn about this -- warning at that time is pointless
anyway, and only serves to scroll away the *real* cause of the panic and
distracts from the real bug.
* So let's extract the WARN_ON() from smp_call_function_map() into all its
callers -- smp_call_function() and smp_call_function_single()
* Also, introduce another caller of smp_call_function_map(), namely
__smp_call_function() (and make smp_call_function() a wrapper over this)
which does *not* warn about disabled irqs
* Use this __smp_call_function() from the panic codepath's smp_send_stop()
We also end having to move code of smp_send_stop() below the definition
of __smp_call_function().
Signed-off-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 1ea4316..b24dcba 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -152,11 +152,6 @@
;
}
-void smp_send_stop(void)
-{
- smp_call_function(stop_this_cpu, NULL, 1, 0);
-}
-
/*
* Structure and data for smp_call_function(). This is designed to minimise
* static memory requirements. It also looks cleaner.
@@ -198,9 +193,6 @@
int cpu;
u64 timeout;
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
if (unlikely(smp_ops == NULL))
return ret;
@@ -270,10 +262,19 @@
return ret;
}
+static int __smp_call_function(void (*func)(void *info), void *info,
+ int nonatomic, int wait)
+{
+ return smp_call_function_map(func,info,nonatomic,wait,cpu_online_map);
+}
+
int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
int wait)
{
- return smp_call_function_map(func,info,nonatomic,wait,cpu_online_map);
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+
+ return __smp_call_function(func, info, nonatomic, wait);
}
EXPORT_SYMBOL(smp_call_function);
@@ -283,6 +284,9 @@
cpumask_t map = CPU_MASK_NONE;
int ret = 0;
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+
if (!cpu_online(cpu))
return -EINVAL;
@@ -299,6 +303,11 @@
}
EXPORT_SYMBOL(smp_call_function_single);
+void smp_send_stop(void)
+{
+ __smp_call_function(stop_this_cpu, NULL, 1, 0);
+}
+
void smp_call_function_interrupt(void)
{
void (*func) (void *info);