aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/atomic_32.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/atomic_32.h')
-rw-r--r--arch/x86/include/asm/atomic_32.h185
1 files changed, 57 insertions, 128 deletions
diff --git a/arch/x86/include/asm/atomic_32.h b/arch/x86/include/asm/atomic_32.h
index 2503d4e64c2..dc5a667ff79 100644
--- a/arch/x86/include/asm/atomic_32.h
+++ b/arch/x86/include/asm/atomic_32.h
@@ -19,7 +19,10 @@
*
* Atomically reads the value of @v.
*/
-#define atomic_read(v) ((v)->counter)
+static inline int atomic_read(const atomic_t *v)
+{
+ return v->counter;
+}
/**
* atomic_set - set atomic variable
@@ -28,7 +31,10 @@
*
* Atomically sets the value of @v to @i.
*/
-#define atomic_set(v, i) (((v)->counter) = (i))
+static inline void atomic_set(atomic_t *v, int i)
+{
+ v->counter = i;
+}
/**
* atomic_add - add integer to atomic variable
@@ -200,8 +206,15 @@ static inline int atomic_sub_return(int i, atomic_t *v)
return atomic_add_return(-i, v);
}
-#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
-#define atomic_xchg(v, new) (xchg(&((v)->counter), (new)))
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+ return cmpxchg(&v->counter, old, new);
+}
+
+static inline int atomic_xchg(atomic_t *v, int new)
+{
+ return xchg(&v->counter, new);
+}
/**
* atomic_add_unless - add unless the number is already a given value
@@ -250,45 +263,12 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
/* An 64bit atomic type */
typedef struct {
- unsigned long long counter;
+ u64 __aligned(8) counter;
} atomic64_t;
#define ATOMIC64_INIT(val) { (val) }
-/**
- * atomic64_read - read atomic64 variable
- * @ptr: pointer of type atomic64_t
- *
- * Atomically reads the value of @v.
- * Doesn't imply a read memory barrier.
- */
-#define __atomic64_read(ptr) ((ptr)->counter)
-
-static inline unsigned long long
-cmpxchg8b(unsigned long long *ptr, unsigned long long old, unsigned long long new)
-{
- asm volatile(
-
- LOCK_PREFIX "cmpxchg8b (%[ptr])\n"
-
- : "=A" (old)
-
- : [ptr] "D" (ptr),
- "A" (old),
- "b" (ll_low(new)),
- "c" (ll_high(new))
-
- : "memory");
-
- return old;
-}
-
-static inline unsigned long long
-atomic64_cmpxchg(atomic64_t *ptr, unsigned long long old_val,
- unsigned long long new_val)
-{
- return cmpxchg8b(&ptr->counter, old_val, new_val);
-}
+extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val);
/**
* atomic64_xchg - xchg atomic64 variable
@@ -298,18 +278,7 @@ atomic64_cmpxchg(atomic64_t *ptr, unsigned long long old_val,
* Atomically xchgs the value of @ptr to @new_val and returns
* the old value.
*/
-
-static inline unsigned long long
-atomic64_xchg(atomic64_t *ptr, unsigned long long new_val)
-{
- unsigned long long old_val;
-
- do {
- old_val = atomic_read(ptr);
- } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
-
- return old_val;
-}
+extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val);
/**
* atomic64_set - set atomic64 variable
@@ -318,10 +287,7 @@ atomic64_xchg(atomic64_t *ptr, unsigned long long new_val)
*
* Atomically sets the value of @ptr to @new_val.
*/
-static inline void atomic64_set(atomic64_t *ptr, unsigned long long new_val)
-{
- atomic64_xchg(ptr, new_val);
-}
+extern void atomic64_set(atomic64_t *ptr, u64 new_val);
/**
* atomic64_read - read atomic64 variable
@@ -329,17 +295,30 @@ static inline void atomic64_set(atomic64_t *ptr, unsigned long long new_val)
*
* Atomically reads the value of @ptr and returns it.
*/
-static inline unsigned long long atomic64_read(atomic64_t *ptr)
+static inline u64 atomic64_read(atomic64_t *ptr)
{
- unsigned long long curr_val;
-
- do {
- curr_val = __atomic64_read(ptr);
- } while (atomic64_cmpxchg(ptr, curr_val, curr_val) != curr_val);
-
- return curr_val;
+ u64 res;
+
+ /*
+ * Note, we inline this atomic64_t primitive because
+ * it only clobbers EAX/EDX and leaves the others
+ * untouched. We also (somewhat subtly) rely on the
+ * fact that cmpxchg8b returns the current 64-bit value
+ * of the memory location we are touching:
+ */
+ asm volatile(
+ "mov %%ebx, %%eax\n\t"
+ "mov %%ecx, %%edx\n\t"
+ LOCK_PREFIX "cmpxchg8b %1\n"
+ : "=&A" (res)
+ : "m" (*ptr)
+ );
+
+ return res;
}
+extern u64 atomic64_read(atomic64_t *ptr);
+
/**
* atomic64_add_return - add and return
* @delta: integer value to add
@@ -347,34 +326,14 @@ static inline unsigned long long atomic64_read(atomic64_t *ptr)
*
* Atomically adds @delta to @ptr and returns @delta + *@ptr
*/
-static inline unsigned long long
-atomic64_add_return(unsigned long long delta, atomic64_t *ptr)
-{
- unsigned long long old_val, new_val;
-
- do {
- old_val = atomic_read(ptr);
- new_val = old_val + delta;
-
- } while (atomic64_cmpxchg(ptr, old_val, new_val) != old_val);
-
- return new_val;
-}
-
-static inline long atomic64_sub_return(unsigned long long delta, atomic64_t *ptr)
-{
- return atomic64_add_return(-delta, ptr);
-}
+extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr);
-static inline long atomic64_inc_return(atomic64_t *ptr)
-{
- return atomic64_add_return(1, ptr);
-}
-
-static inline long atomic64_dec_return(atomic64_t *ptr)
-{
- return atomic64_sub_return(1, ptr);
-}
+/*
+ * Other variants with different arithmetic operators:
+ */
+extern u64 atomic64_sub_return(u64 delta, atomic64_t *ptr);
+extern u64 atomic64_inc_return(atomic64_t *ptr);
+extern u64 atomic64_dec_return(atomic64_t *ptr);
/**
* atomic64_add - add integer to atomic64 variable
@@ -383,10 +342,7 @@ static inline long atomic64_dec_return(atomic64_t *ptr)
*
* Atomically adds @delta to @ptr.
*/
-static inline void atomic64_add(unsigned long long delta, atomic64_t *ptr)
-{
- atomic64_add_return(delta, ptr);
-}
+extern void atomic64_add(u64 delta, atomic64_t *ptr);
/**
* atomic64_sub - subtract the atomic64 variable
@@ -395,10 +351,7 @@ static inline void atomic64_add(unsigned long long delta, atomic64_t *ptr)
*
* Atomically subtracts @delta from @ptr.
*/
-static inline void atomic64_sub(unsigned long long delta, atomic64_t *ptr)
-{
- atomic64_add(-delta, ptr);
-}
+extern void atomic64_sub(u64 delta, atomic64_t *ptr);
/**
* atomic64_sub_and_test - subtract value from variable and test result
@@ -409,13 +362,7 @@ static inline void atomic64_sub(unsigned long long delta, atomic64_t *ptr)
* true if the result is zero, or false for all
* other cases.
*/
-static inline int
-atomic64_sub_and_test(unsigned long long delta, atomic64_t *ptr)
-{
- unsigned long long old_val = atomic64_sub_return(delta, ptr);
-
- return old_val == 0;
-}
+extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr);
/**
* atomic64_inc - increment atomic64 variable
@@ -423,10 +370,7 @@ atomic64_sub_and_test(unsigned long long delta, atomic64_t *ptr)
*
* Atomically increments @ptr by 1.
*/
-static inline void atomic64_inc(atomic64_t *ptr)
-{
- atomic64_add(1, ptr);
-}
+extern void atomic64_inc(atomic64_t *ptr);
/**
* atomic64_dec - decrement atomic64 variable
@@ -434,10 +378,7 @@ static inline void atomic64_inc(atomic64_t *ptr)
*
* Atomically decrements @ptr by 1.
*/
-static inline void atomic64_dec(atomic64_t *ptr)
-{
- atomic64_sub(1, ptr);
-}
+extern void atomic64_dec(atomic64_t *ptr);
/**
* atomic64_dec_and_test - decrement and test
@@ -447,10 +388,7 @@ static inline void atomic64_dec(atomic64_t *ptr)
* returns true if the result is 0, or false for all other
* cases.
*/
-static inline int atomic64_dec_and_test(atomic64_t *ptr)
-{
- return atomic64_sub_and_test(1, ptr);
-}
+extern int atomic64_dec_and_test(atomic64_t *ptr);
/**
* atomic64_inc_and_test - increment and test
@@ -460,10 +398,7 @@ static inline int atomic64_dec_and_test(atomic64_t *ptr)
* and returns true if the result is zero, or false for all
* other cases.
*/
-static inline int atomic64_inc_and_test(atomic64_t *ptr)
-{
- return atomic64_sub_and_test(-1, ptr);
-}
+extern int atomic64_inc_and_test(atomic64_t *ptr);
/**
* atomic64_add_negative - add and test if negative
@@ -474,13 +409,7 @@ static inline int atomic64_inc_and_test(atomic64_t *ptr)
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
-static inline int
-atomic64_add_negative(unsigned long long delta, atomic64_t *ptr)
-{
- long long old_val = atomic64_add_return(delta, ptr);
-
- return old_val < 0;
-}
+extern int atomic64_add_negative(u64 delta, atomic64_t *ptr);
#include <asm-generic/atomic-long.h>
#endif /* _ASM_X86_ATOMIC_32_H */