Initial import

1 files changed, 242 insertions, 0 deletions

diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
new file mode 100644
index 000000000..8f8eafbed
--- /dev/null
+++ b/arch/alpha/include/asm/atomic.h
@@ -0,0 +1,242 @@
+#ifndef _ALPHA_ATOMIC_H
+#define _ALPHA_ATOMIC_H
+
+#include <linux/types.h>
+#include <asm/barrier.h>
+#include <asm/cmpxchg.h>
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc...
+ *
+ * But use these as seldom as possible since they are much slower
+ * than regular operations.
+ */
+
+
+#define ATOMIC_INIT(i)		{ (i) }
+#define ATOMIC64_INIT(i)	{ (i) }
+
+#define atomic_read(v)		ACCESS_ONCE((v)->counter)
+#define atomic64_read(v)	ACCESS_ONCE((v)->counter)
+
+#define atomic_set(v,i)		((v)->counter = (i))
+#define atomic64_set(v,i)	((v)->counter = (i))
+
+/*
+ * To get proper branch prediction for the main line, we must branch
+ * forward to code at the end of this object's .text section, then
+ * branch back to restart the operation.
+ */
+
+#define ATOMIC_OP(op)							\
+static __inline__ void atomic_##op(int i, atomic_t * v)			\
+{									\
+	unsigned long temp;						\
+	__asm__ __volatile__(						\
+	"1:	ldl_l %0,%1\n"						\
+	"	" #op "l %0,%2,%0\n"					\
+	"	stl_c %0,%1\n"						\
+	"	beq %0,2f\n"						\
+	".subsection 2\n"						\
+	"2:	br 1b\n"						\
+	".previous"							\
+	:"=&r" (temp), "=m" (v->counter)				\
+	:"Ir" (i), "m" (v->counter));					\
+}									\
+
+#define ATOMIC_OP_RETURN(op)						\
+static inline int atomic_##op##_return(int i, atomic_t *v)		\
+{									\
+	long temp, result;						\
+	smp_mb();							\
+	__asm__ __volatile__(						\
+	"1:	ldl_l %0,%1\n"						\
+	"	" #op "l %0,%3,%2\n"					\
+	"	" #op "l %0,%3,%0\n"					\
+	"	stl_c %0,%1\n"						\
+	"	beq %0,2f\n"						\
+	".subsection 2\n"						\
+	"2:	br 1b\n"						\
+	".previous"							\
+	:"=&r" (temp), "=m" (v->counter), "=&r" (result)		\
+	:"Ir" (i), "m" (v->counter) : "memory");			\
+	smp_mb();							\
+	return result;							\
+}
+
+#define ATOMIC64_OP(op)							\
+static __inline__ void atomic64_##op(long i, atomic64_t * v)		\
+{									\
+	unsigned long temp;						\
+	__asm__ __volatile__(						\
+	"1:	ldq_l %0,%1\n"						\
+	"	" #op "q %0,%2,%0\n"					\
+	"	stq_c %0,%1\n"						\
+	"	beq %0,2f\n"						\
+	".subsection 2\n"						\
+	"2:	br 1b\n"						\
+	".previous"							\
+	:"=&r" (temp), "=m" (v->counter)				\
+	:"Ir" (i), "m" (v->counter));					\
+}									\
+
+#define ATOMIC64_OP_RETURN(op)						\
+static __inline__ long atomic64_##op##_return(long i, atomic64_t * v)	\
+{									\
+	long temp, result;						\
+	smp_mb();							\
+	__asm__ __volatile__(						\
+	"1:	ldq_l %0,%1\n"						\
+	"	" #op "q %0,%3,%2\n"					\
+	"	" #op "q %0,%3,%0\n"					\
+	"	stq_c %0,%1\n"						\
+	"	beq %0,2f\n"						\
+	".subsection 2\n"						\
+	"2:	br 1b\n"						\
+	".previous"							\
+	:"=&r" (temp), "=m" (v->counter), "=&r" (result)		\
+	:"Ir" (i), "m" (v->counter) : "memory");			\
+	smp_mb();							\
+	return result;							\
+}
+
+#define ATOMIC_OPS(opg)							\
+	ATOMIC_OP(opg)							\
+	ATOMIC_OP_RETURN(opg)						\
+	ATOMIC64_OP(opg)						\
+	ATOMIC64_OP_RETURN(opg)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#undef ATOMIC_OPS
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define atomic64_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new))
+#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
+
+#define atomic_cmpxchg(v, old, new) (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 the old value of @v.
+ */
+static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
+{
+	int c, new, old;
+	smp_mb();
+	__asm__ __volatile__(
+	"1:	ldl_l	%[old],%[mem]\n"
+	"	cmpeq	%[old],%[u],%[c]\n"
+	"	addl	%[old],%[a],%[new]\n"
+	"	bne	%[c],2f\n"
+	"	stl_c	%[new],%[mem]\n"
+	"	beq	%[new],3f\n"
+	"2:\n"
+	".subsection 2\n"
+	"3:	br	1b\n"
+	".previous"
+	: [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c)
+	: [mem] "m"(*v), [a] "rI"(a), [u] "rI"((long)u)
+	: "memory");
+	smp_mb();
+	return old;
+}
+
+
+/**
+ * atomic64_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_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 true iff @v was not @u.
+ */
+static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
+{
+	long c, tmp;
+	smp_mb();
+	__asm__ __volatile__(
+	"1:	ldq_l	%[tmp],%[mem]\n"
+	"	cmpeq	%[tmp],%[u],%[c]\n"
+	"	addq	%[tmp],%[a],%[tmp]\n"
+	"	bne	%[c],2f\n"
+	"	stq_c	%[tmp],%[mem]\n"
+	"	beq	%[tmp],3f\n"
+	"2:\n"
+	".subsection 2\n"
+	"3:	br	1b\n"
+	".previous"
+	: [tmp] "=&r"(tmp), [c] "=&r"(c)
+	: [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u)
+	: "memory");
+	smp_mb();
+	return !c;
+}
+
+/*
+ * atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
+ */
+static inline long atomic64_dec_if_positive(atomic64_t *v)
+{
+	long old, tmp;
+	smp_mb();
+	__asm__ __volatile__(
+	"1:	ldq_l	%[old],%[mem]\n"
+	"	subq	%[old],1,%[tmp]\n"
+	"	ble	%[old],2f\n"
+	"	stq_c	%[tmp],%[mem]\n"
+	"	beq	%[tmp],3f\n"
+	"2:\n"
+	".subsection 2\n"
+	"3:	br	1b\n"
+	".previous"
+	: [old] "=&r"(old), [tmp] "=&r"(tmp)
+	: [mem] "m"(*v)
+	: "memory");
+	smp_mb();
+	return old - 1;
+}
+
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+
+#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
+#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
+
+#define atomic_dec_return(v) atomic_sub_return(1,(v))
+#define atomic64_dec_return(v) atomic64_sub_return(1,(v))
+
+#define atomic_inc_return(v) atomic_add_return(1,(v))
+#define atomic64_inc_return(v) atomic64_add_return(1,(v))
+
+#define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0)
+#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i), (v)) == 0)
+
+#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
+#define atomic64_inc_and_test(v) (atomic64_add_return(1, (v)) == 0)
+
+#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
+#define atomic64_dec_and_test(v) (atomic64_sub_return(1, (v)) == 0)
+
+#define atomic_inc(v) atomic_add(1,(v))
+#define atomic64_inc(v) atomic64_add(1,(v))
+
+#define atomic_dec(v) atomic_sub(1,(v))
+#define atomic64_dec(v) atomic64_sub(1,(v))
+
+#endif /* _ALPHA_ATOMIC_H */