Merge branch 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6

[linux-2.6-omap-h63xx.git] / include / asm-x86 / bitops_32.h

diff --git a/include/asm-x86/bitops_32.h b/include/asm-x86/bitops_32.h
index a20fe9822f6002db96607331fd7ae50f0a95ee58..0b40f6d20bea207081fd739f8eae5b9bb3ac12f4 100644 (file)
--- a/include/asm-x86/bitops_32.h
+++ b/include/asm-x86/bitops_32.h
@@ -5,6 +5,10 @@
  * Copyright 1992, Linus Torvalds.
  */
 
+#ifndef _LINUX_BITOPS_H
+#error only <linux/bitops.h> can be included directly
+#endif
+
 #include <linux/compiler.h>
 #include <asm/alternative.h>
 
@@ -76,6 +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__(
@@ -83,6 +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()
 
@@ -141,6 +178,18 @@ static inline int test_and_set_bit(int nr, volatile unsigned long * addr)
        return oldbit;
 }
 
+/**
+ * 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.
+ */
+static inline int test_and_set_bit_lock(int nr, volatile unsigned long *addr)
+{
+       return test_and_set_bit(nr, addr);
+}
+
 /**
  * __test_and_set_bit - Set a bit and return its old value
  * @nr: Bit to set