--- /dev/null
+#ifndef _X86_64_ATOMIC_H
+#define _X86_64_ATOMIC_H
+
+/* atomic_t should be 32 bit signed type */
+
+/*
+ * Atomic operations that C can't guarantee us. Useful for
+ * resource counting etc..
+ */
+
+/*
+ * Make sure gcc doesn't try to be clever and move things around
+ * on us. We need to use _exactly_ the address the user gave us,
+ * not some alias that contains the same information.
+ */
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i) { (i) }
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+#define atomic_read(v) ((v)->counter)
+
+/**
+ * atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ */
+#define atomic_set(v,i) (((v)->counter) = (i))
+
+/**
+ * atomic_add - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v.
+ */
+static __inline__ void atomic_add(int i, atomic_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; addl %1,%0"
+ :"=m" (v->counter)
+ :"ir" (i), "m" (v->counter));
+}
+
+/**
+ * atomic_sub - subtract the atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v.
+ */
+static __inline__ void atomic_sub(int i, atomic_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; subl %1,%0"
+ :"=m" (v->counter)
+ :"ir" (i), "m" (v->counter));
+}
+
+/**
+ * atomic_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+static __inline__ int atomic_sub_and_test(int i, atomic_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; subl %2,%0; sete %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"ir" (i), "m" (v->counter) : "memory");
+ return c;
+}
+
+/**
+ * atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1.
+ */
+static __inline__ void atomic_inc(atomic_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; incl %0"
+ :"=m" (v->counter)
+ :"m" (v->counter));
+}
+
+/**
+ * atomic_dec - decrement atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1.
+ */
+static __inline__ void atomic_dec(atomic_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; decl %0"
+ :"=m" (v->counter)
+ :"m" (v->counter));
+}
+
+/**
+ * atomic_dec_and_test - decrement and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+static __inline__ int atomic_dec_and_test(atomic_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; decl %0; sete %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"m" (v->counter) : "memory");
+ return c != 0;
+}
+
+/**
+ * atomic_inc_and_test - increment and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+static __inline__ int atomic_inc_and_test(atomic_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; incl %0; sete %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"m" (v->counter) : "memory");
+ return c != 0;
+}
+
+/**
+ * atomic_add_negative - add and test if negative
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+static __inline__ int atomic_add_negative(int i, atomic_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; addl %2,%0; sets %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"ir" (i), "m" (v->counter) : "memory");
+ return c;
+}
+
+/**
+ * atomic_add_return - add and return
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static __inline__ int atomic_add_return(int i, atomic_t *v)
+{
+ int __i = i;
+ __asm__ __volatile__(
+ "lock ; xaddl %0, %1;"
+ :"=r"(i)
+ :"m"(v->counter), "0"(i));
+ return i + __i;
+}
+
+static __inline__ int atomic_sub_return(int i, atomic_t *v)
+{
+ return atomic_add_return(-i,v);
+}
+
+#define atomic_inc_return(v) (atomic_add_return(1,v))
+#define atomic_dec_return(v) (atomic_sub_return(1,v))
+
+/* An 64bit atomic type */
+
+typedef struct { volatile long counter; } atomic64_t;
+
+#define ATOMIC64_INIT(i) { (i) }
+
+/**
+ * atomic64_read - read atomic64 variable
+ * @v: pointer of type atomic64_t
+ *
+ * Atomically reads the value of @v.
+ * Doesn't imply a read memory barrier.
+ */
+#define atomic64_read(v) ((v)->counter)
+
+/**
+ * atomic64_set - set atomic64 variable
+ * @v: pointer to type atomic64_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ */
+#define atomic64_set(v,i) (((v)->counter) = (i))
+
+/**
+ * atomic64_add - add integer to atomic64 variable
+ * @i: integer value to add
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically adds @i to @v.
+ */
+static __inline__ void atomic64_add(long i, atomic64_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; addq %1,%0"
+ :"=m" (v->counter)
+ :"ir" (i), "m" (v->counter));
+}
+
+/**
+ * atomic64_sub - subtract the atomic64 variable
+ * @i: integer value to subtract
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically subtracts @i from @v.
+ */
+static __inline__ void atomic64_sub(long i, atomic64_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; subq %1,%0"
+ :"=m" (v->counter)
+ :"ir" (i), "m" (v->counter));
+}
+
+/**
+ * atomic64_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically subtracts @i from @v and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+static __inline__ int atomic64_sub_and_test(long i, atomic64_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; subq %2,%0; sete %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"ir" (i), "m" (v->counter) : "memory");
+ return c;
+}
+
+/**
+ * atomic64_inc - increment atomic64 variable
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically increments @v by 1.
+ */
+static __inline__ void atomic64_inc(atomic64_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; incq %0"
+ :"=m" (v->counter)
+ :"m" (v->counter));
+}
+
+/**
+ * atomic64_dec - decrement atomic64 variable
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically decrements @v by 1.
+ */
+static __inline__ void atomic64_dec(atomic64_t *v)
+{
+ __asm__ __volatile__(
+ "lock ; decq %0"
+ :"=m" (v->counter)
+ :"m" (v->counter));
+}
+
+/**
+ * atomic64_dec_and_test - decrement and test
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically decrements @v by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+static __inline__ int atomic64_dec_and_test(atomic64_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; decq %0; sete %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"m" (v->counter) : "memory");
+ return c != 0;
+}
+
+/**
+ * atomic64_inc_and_test - increment and test
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+static __inline__ int atomic64_inc_and_test(atomic64_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; incq %0; sete %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"m" (v->counter) : "memory");
+ return c != 0;
+}
+
+/**
+ * atomic64_add_negative - add and test if negative
+ * @i: integer value to add
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically adds @i to @v and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+static __inline__ int atomic64_add_negative(long i, atomic64_t *v)
+{
+ unsigned char c;
+
+ __asm__ __volatile__(
+ "lock ; addq %2,%0; sets %1"
+ :"=m" (v->counter), "=qm" (c)
+ :"ir" (i), "m" (v->counter) : "memory");
+ return c;
+}
+
+/**
+ * atomic64_add_return - add and return
+ * @i: integer value to add
+ * @v: pointer to type atomic64_t
+ *
+ * Atomically adds @i to @v and returns @i + @v
+ */
+static __inline__ long atomic64_add_return(long i, atomic64_t *v)
+{
+ long __i = i;
+ __asm__ __volatile__(
+ "lock ; xaddq %0, %1;"
+ :"=r"(i)
+ :"m"(v->counter), "0"(i));
+ return i + __i;
+}
+
+static __inline__ long atomic64_sub_return(long i, atomic64_t *v)
+{
+ return atomic64_add_return(-i,v);
+}
+
+#define atomic64_inc_return(v) (atomic64_add_return(1,v))
+#define atomic64_dec_return(v) (atomic64_sub_return(1,v))
+
+#define atomic_cmpxchg(v, old, new) ((int)cmpxchg(&((v)->counter), old, new))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+/**
+ * atomic_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns non-zero if @v was not @u, and zero otherwise.
+ */
+#define atomic_add_unless(v, a, u) \
+({ \
+ int c, old; \
+ c = atomic_read(v); \
+ for (;;) { \
+ if (unlikely(c == (u))) \
+ break; \
+ old = atomic_cmpxchg((v), c, c + (a)); \
+ if (likely(old == c)) \
+ break; \
+ c = old; \
+ } \
+ c != (u); \
+})
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
+/* These are x86-specific, used by some header files */
+#define atomic_clear_mask(mask, addr) \
+__asm__ __volatile__("lock ; andl %0,%1" \
+: : "r" (~(mask)),"m" (*addr) : "memory")
+
+#define atomic_set_mask(mask, addr) \
+__asm__ __volatile__("lock ; orl %0,%1" \
+: : "r" ((unsigned)mask),"m" (*(addr)) : "memory")
+
+/* Atomic operations are already serializing on x86 */
+#define smp_mb__before_atomic_dec() barrier()
+#define smp_mb__after_atomic_dec() barrier()
+#define smp_mb__before_atomic_inc() barrier()
+#define smp_mb__after_atomic_inc() barrier()
+
+#include <arch-generic/atomic.h>
+#endif
