From 8fd7675c092f79f240246c76728477ec4e7f7f09 Mon Sep 17 00:00:00 2001 From: Satyam Sharma Date: Tue, 18 Sep 2007 09:43:40 +1000 Subject: [PATCH] [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 Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/smp.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 1ea43160f54..b24dcbaeeca 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -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 * 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; u64 timeout; - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); - if (unlikely(smp_ops == NULL)) return ret; @@ -270,10 +262,19 @@ int smp_call_function_map(void (*func) (void *info), void *info, int nonatomic, 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 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info, int 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 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info, int } 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); -- 2.20.1