local_t: alpha extension

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 102 insertions, 24 deletions

diff --git a/include/asm-alpha/local.h b/include/asm-alpha/local.h
index 90a510fa358e..6ad3ea696421 100644
--- a/include/asm-alpha/local.h
+++ b/include/asm-alpha/local.h
@@ -4,37 +4,115 @@
 #include <linux/percpu.h>
 #include <asm/atomic.h>
 
-typedef atomic64_t local_t;
+typedef struct
+{
+        atomic_long_t a;
+} local_t;
 
-#define LOCAL_INIT(i)   ATOMIC64_INIT(i)
-#define local_read(v)   atomic64_read(v)
-#define local_set(v,i)  atomic64_set(v,i)
+#define LOCAL_INIT(i)   { ATOMIC_LONG_INIT(i) }
+#define local_read(l)   atomic_long_read(&(l)->a)
+#define local_set(l,i)  atomic_long_set(&(l)->a, (i))
+#define local_inc(l)    atomic_long_inc(&(l)->a)
+#define local_dec(l)    atomic_long_dec(&(l)->a)
+#define local_add(i,l)  atomic_long_add((i),(&(l)->a))
+#define local_sub(i,l)  atomic_long_sub((i),(&(l)->a))
 
-#define local_inc(v)    atomic64_inc(v)
-#define local_dec(v)    atomic64_dec(v)
-#define local_add(i, v) atomic64_add(i, v)
-#define local_sub(i, v) atomic64_sub(i, v)
+static __inline__ long local_add_return(long i, local_t * l)
+{
+        long temp, result;
+        __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" (l->a.counter), "=&r" (result)
+        :"Ir" (i), "m" (l->a.counter) : "memory");
+        return result;
+}
 
-#define __local_inc(v)          ((v)->counter++)
-#define __local_dec(v)          ((v)->counter++)
-#define __local_add(i,v)        ((v)->counter+=(i))
-#define __local_sub(i,v)        ((v)->counter-=(i))
+static __inline__ long local_sub_return(long i, local_t * l)
+{
+        long temp, result;
+        __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" (l->a.counter), "=&r" (result)
+        :"Ir" (i), "m" (l->a.counter) : "memory");
+        return result;
+}
+
+#define local_cmpxchg(l, o, n) \
+        (cmpxchg_local(&((l)->a.counter), (o), (n)))
+#define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
+
+/**
+ * local_add_unless - add unless the number is a given value
+ * @l: pointer of type local_t
+ * @a: the amount to add to l...
+ * @u: ...unless l is equal to u.
+ *
+ * Atomically adds @a to @l, so long as it was not @u.
+ * Returns non-zero if @l was not @u, and zero otherwise.
+ */
+#define local_add_unless(l, a, u)                               \
+({                                                              \
+        long c, old;                                            \
+        c = local_read(l);                                      \
+        for (;;) {                                              \
+                if (unlikely(c == (u)))                         \
+                        break;                                  \
+                old = local_cmpxchg((l), c, c + (a));   \
+                if (likely(old == c))                           \
+                        break;                                  \
+                c = old;                                        \
+        }                                                       \
+        c != (u);                                               \
+})
+#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
+
+#define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
+
+#define local_dec_return(l) local_sub_return(1,(l))
+
+#define local_inc_return(l) local_add_return(1,(l))
+
+#define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
+
+#define local_inc_and_test(l) (local_add_return(1, (l)) == 0)
+
+#define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
+
+/* Verify if faster than atomic ops */
+#define __local_inc(l)          ((l)->a.counter++)
+#define __local_dec(l)          ((l)->a.counter++)
+#define __local_add(i,l)        ((l)->a.counter+=(i))
+#define __local_sub(i,l)        ((l)->a.counter-=(i))
 
 /* Use these for per-cpu local_t variables: on some archs they are
  * much more efficient than these naive implementations.  Note they take
  * a variable, not an address.
  */
-#define cpu_local_read(v)       local_read(&__get_cpu_var(v))
-#define cpu_local_set(v, i)     local_set(&__get_cpu_var(v), (i))
-
-#define cpu_local_inc(v)        local_inc(&__get_cpu_var(v))
-#define cpu_local_dec(v)        local_dec(&__get_cpu_var(v))
-#define cpu_local_add(i, v)     local_add((i), &__get_cpu_var(v))
-#define cpu_local_sub(i, v)     local_sub((i), &__get_cpu_var(v))
-
-#define __cpu_local_inc(v)      __local_inc(&__get_cpu_var(v))
-#define __cpu_local_dec(v)      __local_dec(&__get_cpu_var(v))
-#define __cpu_local_add(i, v)   __local_add((i), &__get_cpu_var(v))
-#define __cpu_local_sub(i, v)   __local_sub((i), &__get_cpu_var(v))
+#define cpu_local_read(l)       local_read(&__get_cpu_var(l))
+#define cpu_local_set(l, i)     local_set(&__get_cpu_var(l), (i))
+
+#define cpu_local_inc(l)        local_inc(&__get_cpu_var(l))
+#define cpu_local_dec(l)        local_dec(&__get_cpu_var(l))
+#define cpu_local_add(i, l)     local_add((i), &__get_cpu_var(l))
+#define cpu_local_sub(i, l)     local_sub((i), &__get_cpu_var(l))
+
+#define __cpu_local_inc(l)      __local_inc(&__get_cpu_var(l))
+#define __cpu_local_dec(l)      __local_dec(&__get_cpu_var(l))
+#define __cpu_local_add(i, l)   __local_add((i), &__get_cpu_var(l))
+#define __cpu_local_sub(i, l)   __local_sub((i), &__get_cpu_var(l))
 
 #endif /* _ALPHA_LOCAL_H */