Alpha can avoid one mb when acquiring a lock with test_and_set_bit_lock.
Signed-off-by: Nick Piggin <[EMAIL PROTECTED]>
---
include/asm-alpha/bitops.h | 42 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)
Index: linux-2.6/include/asm-alpha/bitops.h
===================================================================
--- linux-2.6.orig/include/asm-alpha/bitops.h
+++ linux-2.6/include/asm-alpha/bitops.h
@@ -69,6 +69,13 @@ clear_bit(unsigned long nr, volatile voi
:"Ir" (1UL << (nr & 31)), "m" (*m));
}
+static inline void
+clear_bit_unlock(unsigned long nr, volatile void * addr)
+{
+ smp_mb();
+ clear_bit(nr, addr);
+}
+
/*
* WARNING: non atomic version.
*/
@@ -81,6 +88,13 @@ __clear_bit(unsigned long nr, volatile v
}
static inline void
+__clear_bit_unlock(unsigned long nr, volatile void * addr)
+{
+ smp_mb();
+ __clear_bit(nr, addr);
+}
+
+static inline void
change_bit(unsigned long nr, volatile void * addr)
{
unsigned long temp;
@@ -139,6 +153,33 @@ test_and_set_bit(unsigned long nr, volat
return oldbit != 0;
}
+static inline int
+test_and_set_bit_lock(unsigned long nr, volatile void *addr)
+{
+ unsigned long oldbit;
+ unsigned long temp;
+ int *m = ((int *) addr) + (nr >> 5);
+
+ __asm__ __volatile__(
+ "1: ldl_l %0,%4\n"
+ " and %0,%3,%2\n"
+ " bne %2,2f\n"
+ " xor %0,%3,%0\n"
+ " stl_c %0,%1\n"
+ " beq %0,3f\n"
+ "2:\n"
+#ifdef CONFIG_SMP
+ " mb\n"
+#endif
+ ".subsection 2\n"
+ "3: br 1b\n"
+ ".previous"
+ :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
+ :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
+
+ return oldbit != 0;
+}
+
/*
* WARNING: non atomic version.
*/
@@ -376,7 +417,6 @@ static inline unsigned int hweight8(unsi
#else
#include <asm-generic/bitops/hweight.h>
#endif
-#include <asm-generic/bitops/lock.h>
#endif /* __KERNEL__ */
-
To unsubscribe from this list: send the line "unsubscribe linux-arch" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
