aboutsummaryrefslogtreecommitdiff
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.h267
1 files changed, 267 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h
new file mode 100644
index 00000000000..ca88e54dec9
--- /dev/null
+++ b/arch/alpha/include/asm/atomic.h
@@ -0,0 +1,267 @@
+#ifndef _ALPHA_ATOMIC_H
+#define _ALPHA_ATOMIC_H
+
+#include <asm/barrier.h>
+#include <asm/system.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.
+ */
+
+
+/*
+ * Counter is volatile to 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;
+typedef struct { volatile long counter; } atomic64_t;
+
+#define ATOMIC_INIT(i) ( (atomic_t) { (i) } )
+#define ATOMIC64_INIT(i) ( (atomic64_t) { (i) } )
+
+#define atomic_read(v) ((v)->counter + 0)
+#define atomic64_read(v) ((v)->counter + 0)
+
+#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.
+ */
+
+static __inline__ void atomic_add(int i, atomic_t * v)
+{
+ unsigned long temp;
+ __asm__ __volatile__(
+ "1: ldl_l %0,%1\n"
+ " addl %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));
+}
+
+static __inline__ void atomic64_add(long i, atomic64_t * v)
+{
+ unsigned long temp;
+ __asm__ __volatile__(
+ "1: ldq_l %0,%1\n"
+ " addq %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));
+}
+
+static __inline__ void atomic_sub(int i, atomic_t * v)
+{
+ unsigned long temp;
+ __asm__ __volatile__(
+ "1: ldl_l %0,%1\n"
+ " subl %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));
+}
+
+static __inline__ void atomic64_sub(long i, atomic64_t * v)
+{
+ unsigned long temp;
+ __asm__ __volatile__(
+ "1: ldq_l %0,%1\n"
+ " subq %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));
+}
+
+
+/*
+ * Same as above, but return the result value
+ */
+static inline int atomic_add_return(int i, atomic_t *v)
+{
+ long temp, result;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldl_l %0,%1\n"
+ " addl %0,%3,%2\n"
+ " addl %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;
+}
+
+static __inline__ long atomic64_add_return(long i, atomic64_t * v)
+{
+ long temp, result;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldq_l %0,%1\n"
+ " addq %0,%3,%2\n"
+ " addq %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;
+}
+
+static __inline__ long atomic_sub_return(int i, atomic_t * v)
+{
+ long temp, result;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldl_l %0,%1\n"
+ " subl %0,%3,%2\n"
+ " subl %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;
+}
+
+static __inline__ long atomic64_sub_return(long i, atomic64_t * v)
+{
+ long temp, result;
+ smp_mb();
+ __asm__ __volatile__(
+ "1: ldq_l %0,%1\n"
+ " subq %0,%3,%2\n"
+ " subq %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 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 non-zero if @v was not @u, and zero otherwise.
+ */
+static __inline__ int atomic_add_unless(atomic_t *v, int a, int 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;
+ }
+ return c != (u);
+}
+
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
+/**
+ * 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 non-zero if @v was not @u, and zero otherwise.
+ */
+static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
+{
+ long c, old;
+ c = atomic64_read(v);
+ for (;;) {
+ if (unlikely(c == (u)))
+ break;
+ old = atomic64_cmpxchg((v), c, c + (a));
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+ return c != (u);
+}
+
+#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))
+
+#define smp_mb__before_atomic_dec() smp_mb()
+#define smp_mb__after_atomic_dec() smp_mb()
+#define smp_mb__before_atomic_inc() smp_mb()
+#define smp_mb__after_atomic_inc() smp_mb()
+
+#include <asm-generic/atomic.h>
+#endif /* _ALPHA_ATOMIC_H */
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-09 22:28:14 +0000