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authorDavid S. Miller <davem@sunset.davemloft.net>2006-01-23 21:03:56 -0800
committerDavid S. Miller <davem@sunset.davemloft.net>2006-01-23 21:03:56 -0800
commitd3ed309a718bc6f79dc485a6d18731990daeee5e (patch)
treede908eec9cff81303038b0523169027748f38fa0 /include/asm-sparc64/spinlock.h
parent4415863773eb0eeceba7318238ec0f63b0b5847a (diff)
downloadlinux-d3ed309a718bc6f79dc485a6d18731990daeee5e.tar.gz
[SPARC64]: Implement __raw_read_trylock()
generic__raw_read_trylock() just does a raw_read_lock() so that isn't very useful. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/asm-sparc64/spinlock.h')
-rw-r--r--include/asm-sparc64/spinlock.h24
1 files changed, 23 insertions, 1 deletions
diff --git a/include/asm-sparc64/spinlock.h b/include/asm-sparc64/spinlock.h
index ec85d12d73b..508c416e9d6 100644
--- a/include/asm-sparc64/spinlock.h
+++ b/include/asm-sparc64/spinlock.h
@@ -131,6 +131,28 @@ static void inline __read_lock(raw_rwlock_t *lock)
: "memory");
}
+static int inline __read_trylock(raw_rwlock_t *lock)
+{
+ int tmp1, tmp2;
+
+ __asm__ __volatile__ (
+"1: ldsw [%2], %0\n"
+" brlz,a,pn %0, 2f\n"
+" mov 0, %0\n"
+" add %0, 1, %1\n"
+" cas [%2], %0, %1\n"
+" cmp %0, %1\n"
+" membar #StoreLoad | #StoreStore\n"
+" bne,pn %%icc, 1b\n"
+" mov 1, %0\n"
+"2:"
+ : "=&r" (tmp1), "=&r" (tmp2)
+ : "r" (lock)
+ : "memory");
+
+ return tmp1;
+}
+
static void inline __read_unlock(raw_rwlock_t *lock)
{
unsigned long tmp1, tmp2;
@@ -211,12 +233,12 @@ static int inline __write_trylock(raw_rwlock_t *lock)
}
#define __raw_read_lock(p) __read_lock(p)
+#define __raw_read_trylock(p) __read_trylock(p)
#define __raw_read_unlock(p) __read_unlock(p)
#define __raw_write_lock(p) __write_lock(p)
#define __raw_write_unlock(p) __write_unlock(p)
#define __raw_write_trylock(p) __write_trylock(p)
-#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
#define __raw_read_can_lock(rw) (!((rw)->lock & 0x80000000UL))
#define __raw_write_can_lock(rw) (!(rw)->lock)