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-rw-r--r--include/asm-generic/atomic.h16
1 files changed, 15 insertions, 1 deletions
diff --git a/include/asm-generic/atomic.h b/include/asm-generic/atomic.h
index 4c56e0daae9..e37963c1df4 100644
--- a/include/asm-generic/atomic.h
+++ b/include/asm-generic/atomic.h
@@ -16,7 +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
/*
@@ -34,7 +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
@@ -55,6 +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;
@@ -68,6 +75,7 @@ static inline int atomic_add_return(int i, atomic_t *v)
return temp;
}
+#endif
/**
* atomic_sub_return - subtract integer from atomic variable
@@ -76,6 +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;
@@ -89,6 +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)
{
@@ -147,6 +157,7 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u)
*
* 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;
@@ -156,6 +167,7 @@ static inline void atomic_clear_mask(unsigned long mask, atomic_t *v)
v->counter &= mask;
raw_local_irq_restore(flags);
}
+#endif
/**
* atomic_set_mask - Atomically set bits in atomic variable
@@ -164,6 +176,7 @@ static inline void atomic_clear_mask(unsigned long mask, atomic_t *v)
*
* 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;
@@ -172,6 +185,7 @@ static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
v->counter |= mask;
raw_local_irq_restore(flags);
}
+#endif
/* Assume that atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()