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authorIngo Molnar <mingo@elte.hu>2008-08-26 10:25:59 +0200
committerIngo Molnar <mingo@elte.hu>2008-08-26 10:25:59 +0200
commit3cf430b0636045dc524759a0852293ba037732a7 (patch)
tree2c4e03f9028dc23ab4e6ca5a3a5a263af397984f /arch/alpha/include/asm/local.h
parent93dcf55f828b035fc93fc19eb03c1390e1e6d570 (diff)
parent83097aca8567a0bd593534853b71fe0fa9a75d69 (diff)
Merge branch 'linus' into sched/devel
Diffstat (limited to 'arch/alpha/include/asm/local.h')
-rw-r--r--arch/alpha/include/asm/local.h118
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/local.h b/arch/alpha/include/asm/local.h
new file mode 100644
index 00000000000..6ad3ea69642
--- /dev/null
+++ b/arch/alpha/include/asm/local.h
@@ -0,0 +1,118 @@
+#ifndef _ALPHA_LOCAL_H
+#define _ALPHA_LOCAL_H
+
+#include <linux/percpu.h>
+#include <asm/atomic.h>
+
+typedef struct
+{
+ atomic_long_t a;
+} local_t;
+
+#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))
+
+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;
+}
+
+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(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 */