From bf7ececa9b68f4720f1ce344f442435660bcdae7 Mon Sep 17 00:00:00 2001
From: Keith Owens <kaos@sgi.com>
Date: Sat, 10 Dec 2005 14:24:28 +1100
Subject: [PATCH] [IA64] Define an ia64 version of __raw_read_trylock
IA64 is using the generic version of __raw_read_trylock, which always
waits for the lock to be free instead of returning when the lock is in
use. Define an ia64 version of __raw_read_trylock which behaves
correctly, and drop the generic one.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
include/asm-ia64/spinlock.h | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/include/asm-ia64/spinlock.h b/include/asm-ia64/spinlock.h
index 5b78611411c30..0c91a76c5ea3c 100644
--- a/include/asm-ia64/spinlock.h
+++ b/include/asm-ia64/spinlock.h
@@ -201,6 +201,16 @@ static inline void __raw_write_unlock(raw_rwlock_t *x)
#endif /* !ASM_SUPPORTED */
-#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
+static inline int __raw_read_trylock(raw_rwlock_t *x)
+{
+ union {
+ raw_rwlock_t lock;
+ __u32 word;
+ } old, new;
+ old.lock = new.lock = *x;
+ old.lock.write_lock = new.lock.write_lock = 0;
+ ++new.lock.read_counter;
+ return (u32)ia64_cmpxchg4_acq((__u32 *)(x), new.word, old.word) == old.word;
+}
#endif /* _ASM_IA64_SPINLOCK_H */
--
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