summaryrefslogtreecommitdiff
path: root/arch/alpha/include/asm/atomic.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/alpha/include/asm/atomic.h')
-rw-r--r--arch/alpha/include/asm/atomic.h242
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 */
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-11 21:43:55 +0000