summaryrefslogtreecommitdiffstats
path: root/include/asm-generic/atomic.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-generic/atomic.h')
-rw-r--r--include/asm-generic/atomic.h59
1 files changed, 47 insertions, 12 deletions
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index e994197f84b7..e37963c1df4d 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -1,5 +1,7 @@
/*
- * Generic C implementation of atomic counter operations
+ * Generic C implementation of atomic counter operations. Usable on
+ * UP systems only. Do not include in machine independent code.
+ *
* Originally implemented for MN10300.
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
@@ -14,7 +16,11 @@
#define __ASM_GENERIC_ATOMIC_H
#ifdef CONFIG_SMP
-#error not SMP safe
+/* Force people to define core atomics */
+# if !defined(atomic_add_return) || !defined(atomic_sub_return) || \
+ !defined(atomic_clear_mask) || !defined(atomic_set_mask)
+# error "SMP requires a little arch-specific magic"
+# endif
#endif
/*
@@ -32,7 +38,9 @@
*
* Atomically reads the value of @v.
*/
+#ifndef atomic_read
#define atomic_read(v) (*(volatile int *)&(v)->counter)
+#endif
/**
* atomic_set - set atomic variable
@@ -53,6 +61,7 @@
*
* Atomically adds @i to @v and returns the result
*/
+#ifndef atomic_add_return
static inline int atomic_add_return(int i, atomic_t *v)
{
unsigned long flags;
@@ -66,6 +75,7 @@ static inline int atomic_add_return(int i, atomic_t *v)
return temp;
}
+#endif
/**
* atomic_sub_return - subtract integer from atomic variable
@@ -74,6 +84,7 @@ static inline int atomic_add_return(int i, atomic_t *v)
*
* Atomically subtracts @i from @v and returns the result
*/
+#ifndef atomic_sub_return
static inline int atomic_sub_return(int i, atomic_t *v)
{
unsigned long flags;
@@ -87,6 +98,7 @@ static inline int atomic_sub_return(int i, atomic_t *v)
return temp;
}
+#endif
static inline int atomic_add_negative(int i, atomic_t *v)
{
@@ -117,8 +129,8 @@ static inline void atomic_dec(atomic_t *v)
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0)
-#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
-#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
+#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
+#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
@@ -129,26 +141,51 @@ static inline void atomic_dec(atomic_t *v)
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
-static inline int atomic_add_unless(atomic_t *v, int a, int u)
+static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
while (c != u && (old = atomic_cmpxchg(v, c, c + a)) != c)
c = old;
- return c != u;
+ return c;
}
-#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
-
-static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
+/**
+ * atomic_clear_mask - Atomically clear bits in atomic variable
+ * @mask: Mask of the bits to be cleared
+ * @v: pointer of type atomic_t
+ *
+ * Atomically clears the bits set in @mask from @v
+ */
+#ifndef atomic_clear_mask
+static inline void atomic_clear_mask(unsigned long mask, atomic_t *v)
{
unsigned long flags;
mask = ~mask;
raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
- *addr &= mask;
+ v->counter &= mask;
raw_local_irq_restore(flags);
}
+#endif
+
+/**
+ * atomic_set_mask - Atomically set bits in atomic variable
+ * @mask: Mask of the bits to be set
+ * @v: pointer of type atomic_t
+ *
+ * Atomically sets the bits set in @mask in @v
+ */
+#ifndef atomic_set_mask
+static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
+{
+ unsigned long flags;
+
+ raw_local_irq_save(flags); /* Don't trace it in a irqsoff handler */
+ v->counter |= mask;
+ raw_local_irq_restore(flags);
+}
+#endif
/* Assume that atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()
@@ -156,7 +193,5 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
#define smp_mb__before_atomic_inc() barrier()
#define smp_mb__after_atomic_inc() barrier()
-#include <asm-generic/atomic-long.h>
-
#endif /* __KERNEL__ */
#endif /* __ASM_GENERIC_ATOMIC_H */