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authorDan Williams <dan.j.williams@intel.com>2009-09-08 14:32:24 -0700
committerDan Williams <dan.j.williams@intel.com>2009-09-08 14:32:24 -0700
commita348a7e6fdbcd2d5192a09719a479bb238fde727 (patch)
tree5ff94185f4e5a810777469d7fe7832a8ec2d3430 /include/asm-generic/atomic64.h
parent808347f6a31792079e345ec865e9cfcb6e8ae6b2 (diff)
parent28d0325ce6e0a52f53d8af687e6427fee59004d3 (diff)
Merge commit 'v2.6.31-rc1' into dmaengine
Diffstat (limited to 'include/asm-generic/atomic64.h')
-rw-r--r--include/asm-generic/atomic64.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h
new file mode 100644
index 000000000000..b18ce4f9ee3d
--- /dev/null
+++ b/include/asm-generic/atomic64.h
@@ -0,0 +1,42 @@
+/*
+ * Generic implementation of 64-bit atomics using spinlocks,
+ * useful on processors that don't have 64-bit atomic instructions.
+ *
+ * Copyright © 2009 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef _ASM_GENERIC_ATOMIC64_H
+#define _ASM_GENERIC_ATOMIC64_H
+
+typedef struct {
+ long long counter;
+} atomic64_t;
+
+#define ATOMIC64_INIT(i) { (i) }
+
+extern long long atomic64_read(const atomic64_t *v);
+extern void atomic64_set(atomic64_t *v, long long i);
+extern void atomic64_add(long long a, atomic64_t *v);
+extern long long atomic64_add_return(long long a, atomic64_t *v);
+extern void atomic64_sub(long long a, atomic64_t *v);
+extern long long atomic64_sub_return(long long a, atomic64_t *v);
+extern long long atomic64_dec_if_positive(atomic64_t *v);
+extern long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n);
+extern long long atomic64_xchg(atomic64_t *v, long long new);
+extern int atomic64_add_unless(atomic64_t *v, long long a, long long u);
+
+#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
+#define atomic64_inc(v) atomic64_add(1LL, (v))
+#define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
+#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
+#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
+#define atomic64_dec(v) atomic64_sub(1LL, (v))
+#define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
+#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
+
+#endif /* _ASM_GENERIC_ATOMIC64_H */