From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Wed, 17 Oct 2007 06:25:46 +0000 (-0700)
Subject: lib: percpu_counter_init_irq
X-Git-Tag: v2.6.24-rc1~806
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dc62a30e274d003a4d08fb888f1520add4b21373;p=linux-2.6

lib: percpu_counter_init_irq

provide a way to tell lockdep about percpu_counters that are supposed to be
used from irq safe contexts.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h
index f7ecd38d7e..9007ccdfc1 100644
--- a/include/linux/percpu_counter.h
+++ b/include/linux/percpu_counter.h
@@ -31,6 +31,7 @@ struct percpu_counter {
 #endif
 
 int percpu_counter_init(struct percpu_counter *fbc, s64 amount);
+int percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount);
 void percpu_counter_destroy(struct percpu_counter *fbc);
 void percpu_counter_set(struct percpu_counter *fbc, s64 amount);
 void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch);
@@ -84,6 +85,8 @@ static inline int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 	return 0;
 }
 
+#define percpu_counter_init_irq percpu_counter_init
+
 static inline void percpu_counter_destroy(struct percpu_counter *fbc)
 {
 }
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c
index 3a59d84b2d..9659eabffc 100644
--- a/lib/percpu_counter.c
+++ b/lib/percpu_counter.c
@@ -68,6 +68,8 @@ s64 __percpu_counter_sum(struct percpu_counter *fbc)
 }
 EXPORT_SYMBOL(__percpu_counter_sum);
 
+static struct lock_class_key percpu_counter_irqsafe;
+
 int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 {
 	spin_lock_init(&fbc->lock);
@@ -84,6 +86,16 @@ int percpu_counter_init(struct percpu_counter *fbc, s64 amount)
 }
 EXPORT_SYMBOL(percpu_counter_init);
 
+int percpu_counter_init_irq(struct percpu_counter *fbc, s64 amount)
+{
+	int err;
+
+	err = percpu_counter_init(fbc, amount);
+	if (!err)
+		lockdep_set_class(&fbc->lock, &percpu_counter_irqsafe);
+	return err;
+}
+
 void percpu_counter_destroy(struct percpu_counter *fbc)
 {
 	if (!fbc->counters)