From: Paul Mundt <lethal@linux-sh.org>
Date: Tue, 3 Oct 2006 05:13:09 +0000 (+0900)
Subject: sh: Fixup __raw_read_trylock().
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=fac99d97469e7f91102f97101bea620e5f073196;p=linux-beck.git

sh: Fixup __raw_read_trylock().

generic__raw_read_trylock() was broken, fix up the __raw_read_trylock()
implementation for something sensible. Taken from m32r, which has the
same use cases.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
---

diff --git a/include/asm-sh/spinlock.h b/include/asm-sh/spinlock.h
index 54458fd24981..2586eef07d57 100644
--- a/include/asm-sh/spinlock.h
+++ b/include/asm-sh/spinlock.h
@@ -88,7 +88,14 @@ static inline void __raw_write_unlock(raw_rwlock_t *rw)
 	__raw_spin_unlock(&rw->lock);
 }
 
-#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
+static inline int __raw_read_trylock(raw_rwlock_t *lock)
+{
+	atomic_t *count = (atomic_t*)lock;
+	if (atomic_dec_return(count) >= 0)
+		return 1;
+	atomic_inc(count);
+	return 0;
+}
 
 static inline int __raw_write_trylock(raw_rwlock_t *rw)
 {