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[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>
This commit is contained in:
Satyam Sharma 2007-09-18 09:43:40 +10:00 committed by Paul Mackerras
parent 17b5ee04c0
commit 8fd7675c09
1 changed files with 18 additions and 9 deletions
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27
arch/powerpc/kernel/smp.c
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@ -152,11 +152,6 @@ static void stop_this_cpu(void *dummy)
; ;
} }
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 * Structure and data for smp_call_function(). This is designed to minimise
* static memory requirements. It also looks cleaner. * static memory requirements. It also looks cleaner.
@ -198,9 +193,6 @@ int smp_call_function_map(void (*func) (void *info), void *info, int nonatomic,
int cpu; int cpu;
u64 timeout; u64 timeout;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
if (unlikely(smp_ops == NULL)) if (unlikely(smp_ops == NULL))
return ret; return ret;
@ -270,10 +262,19 @@ int smp_call_function_map(void (*func) (void *info), void *info, int nonatomic,
return ret; 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 smp_call_function(void (*func) (void *info), void *info, int nonatomic,
int wait) 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); EXPORT_SYMBOL(smp_call_function);
@ -283,6 +284,9 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info, int
cpumask_t map = CPU_MASK_NONE; cpumask_t map = CPU_MASK_NONE;
int ret = 0; int ret = 0;
/* Can deadlock when called with interrupts disabled */
WARN_ON(irqs_disabled());
if (!cpu_online(cpu)) if (!cpu_online(cpu))
return -EINVAL; return -EINVAL;
@ -299,6 +303,11 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info, int
} }
EXPORT_SYMBOL(smp_call_function_single); 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 smp_call_function_interrupt(void)
{ {
void (*func) (void *info); void (*func) (void *info);