From: Michal Simek <monstr@monstr.eu>
Date: Tue, 10 Aug 2010 00:18:24 +0000 (-0700)
Subject: asm-generic: use raw_local_irq_save/restore instead local_irq_save/restore
X-Git-Tag: v2.6.36-rc1~479
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=9e58143dc08123c22c5b9f782b2913bd3a07a03d;p=~shefty%2Frdma-dev.git

asm-generic: use raw_local_irq_save/restore instead local_irq_save/restore

The start/stop_critical_timing functions for preemptirqsoff, preemptoff
and irqsoff tracers contain atomic_inc() and atomic_dec() operations.

Atomic operations use local_irq_save/restore macros to ensure atomic
access but they are traced by the same function which is causing recursion
problem.

The reason is when these tracers are turn ON then the
local_irq_save/restore macros are changed in include/linux/irqflags.h to
call trace_hardirqs_on/off which call start/stop_critical_timing.

Microblaze was affected because it uses generic atomic implementation.

Signed-off-by: Michal Simek <monstr@monstr.eu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index 058129e9b04..e53347fbf1d 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -57,11 +57,11 @@ static inline int atomic_add_return(int i, atomic_t *v)
 	unsigned long flags;
 	int temp;
 
-	local_irq_save(flags);
+	raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
 	temp = v->counter;
 	temp += i;
 	v->counter = temp;
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 
 	return temp;
 }
@@ -78,11 +78,11 @@ static inline int atomic_sub_return(int i, atomic_t *v)
 	unsigned long flags;
 	int temp;
 
-	local_irq_save(flags);
+	raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
 	temp = v->counter;
 	temp -= i;
 	v->counter = temp;
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 
 	return temp;
 }
@@ -135,9 +135,9 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
 	unsigned long flags;
 
 	mask = ~mask;
-	local_irq_save(flags);
+	raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
 	*addr &= mask;
-	local_irq_restore(flags);
+	raw_local_irq_restore(flags);
 }
 
 #define atomic_xchg(ptr, v)		(xchg(&(ptr)->counter, (v)))