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Diffstat (limited to 'include/asm-x86/bitops_32.h')
-rw-r--r--include/asm-x86/bitops_32.h43
1 files changed, 42 insertions, 1 deletions
diff --git a/include/asm-x86/bitops_32.h b/include/asm-x86/bitops_32.h
index 3268a341cf49..36ebb5b02b4f 100644
--- a/include/asm-x86/bitops_32.h
+++ b/include/asm-x86/bitops_32.h
@@ -80,6 +80,20 @@ static inline void clear_bit(int nr, volatile unsigned long * addr)
:"Ir" (nr));
}
+/*
+ * clear_bit_unlock - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * clear_bit() is atomic and implies release semantics before the memory
+ * operation. It can be used for an unlock.
+ */
+static inline void clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
+{
+ barrier();
+ clear_bit(nr, addr);
+}
+
static inline void __clear_bit(int nr, volatile unsigned long * addr)
{
__asm__ __volatile__(
@@ -87,6 +101,25 @@ static inline void __clear_bit(int nr, volatile unsigned long * addr)
:"+m" (ADDR)
:"Ir" (nr));
}
+
+/*
+ * __clear_bit_unlock - Clears a bit in memory
+ * @nr: Bit to clear
+ * @addr: Address to start counting from
+ *
+ * __clear_bit() is non-atomic and implies release semantics before the memory
+ * operation. It can be used for an unlock if no other CPUs can concurrently
+ * modify other bits in the word.
+ *
+ * No memory barrier is required here, because x86 cannot reorder stores past
+ * older loads. Same principle as spin_unlock.
+ */
+static inline void __clear_bit_unlock(unsigned long nr, volatile unsigned long *addr)
+{
+ barrier();
+ __clear_bit(nr, addr);
+}
+
#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()
@@ -146,6 +179,15 @@ static inline int test_and_set_bit(int nr, volatile unsigned long * addr)
}
/**
+ * test_and_set_bit_lock - Set a bit and return its old value for lock
+ * @nr: Bit to set
+ * @addr: Address to count from
+ *
+ * This is the same as test_and_set_bit on x86
+ */
+#define test_and_set_bit_lock test_and_set_bit
+
+/**
* __test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
@@ -406,7 +448,6 @@ static inline int fls(int x)
}
#include <asm-generic/bitops/hweight.h>
-#include <asm-generic/bitops/lock.h>
#endif /* __KERNEL__ */