Initial import

1 files changed, 208 insertions, 0 deletions

diff --git a/arch/tile/include/asm/atomic.h b/arch/tile/include/asm/atomic.h
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+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ *
+ * Atomic primitives.
+ */
+
+#ifndef _ASM_TILE_ATOMIC_H
+#define _ASM_TILE_ATOMIC_H
+
+#include <asm/cmpxchg.h>
+
+#ifndef __ASSEMBLY__
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+#define ATOMIC_INIT(i)	{ (i) }
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+static inline int atomic_read(const atomic_t *v)
+{
+	return ACCESS_ONCE(v->counter);
+}
+
+/**
+ * atomic_sub_return - subtract integer and return
+ * @v: pointer of type atomic_t
+ * @i: integer value to subtract
+ *
+ * Atomically subtracts @i from @v and returns @v - @i
+ */
+#define atomic_sub_return(i, v)		atomic_add_return((int)(-(i)), (v))
+
+/**
+ * atomic_sub - subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v.
+ */
+#define atomic_sub(i, v)		atomic_add((int)(-(i)), (v))
+
+/**
+ * atomic_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v and returns true if the result is
+ * zero, or false for all other cases.
+ */
+#define atomic_sub_and_test(i, v)	(atomic_sub_return((i), (v)) == 0)
+
+/**
+ * atomic_inc_return - increment memory and return
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1 and returns the new value.
+ */
+#define atomic_inc_return(v)		atomic_add_return(1, (v))
+
+/**
+ * atomic_dec_return - decrement memory and return
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1 and returns the new value.
+ */
+#define atomic_dec_return(v)		atomic_sub_return(1, (v))
+
+/**
+ * atomic_inc - increment atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1.
+ */
+#define atomic_inc(v)			atomic_add(1, (v))
+
+/**
+ * atomic_dec - decrement atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1.
+ */
+#define atomic_dec(v)			atomic_sub(1, (v))
+
+/**
+ * atomic_dec_and_test - decrement and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically decrements @v by 1 and returns true if the result is 0.
+ */
+#define atomic_dec_and_test(v)		(atomic_dec_return(v) == 0)
+
+/**
+ * atomic_inc_and_test - increment and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1 and returns true if the result is 0.
+ */
+#define atomic_inc_and_test(v)		(atomic_inc_return(v) == 0)
+
+/**
+ * atomic_xchg - atomically exchange contents of memory with a new value
+ * @v: pointer of type atomic_t
+ * @i: integer value to store in memory
+ *
+ * Atomically sets @v to @i and returns old @v
+ */
+static inline int atomic_xchg(atomic_t *v, int n)
+{
+	return xchg(&v->counter, n);
+}
+
+/**
+ * atomic_cmpxchg - atomically exchange contents of memory if it matches
+ * @v: pointer of type atomic_t
+ * @o: old value that memory should have
+ * @n: new value to write to memory if it matches
+ *
+ * Atomically checks if @v holds @o and replaces it with @n if so.
+ * Returns the old value at @v.
+ */
+static inline int atomic_cmpxchg(atomic_t *v, int o, int n)
+{
+	return cmpxchg(&v->counter, o, n);
+}
+
+/**
+ * atomic_add_negative - add and test if negative
+ * @v: pointer of type atomic_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @v and returns true if the result is
+ * negative, or false when result is greater than or equal to zero.
+ */
+#define atomic_add_negative(i, v)	(atomic_add_return((i), (v)) < 0)
+
+#endif /* __ASSEMBLY__ */
+
+#ifndef __tilegx__
+#include <asm/atomic_32.h>
+#else
+#include <asm/atomic_64.h>
+#endif
+
+#ifndef __ASSEMBLY__
+
+/**
+ * atomic64_xchg - atomically exchange contents of memory with a new value
+ * @v: pointer of type atomic64_t
+ * @i: integer value to store in memory
+ *
+ * Atomically sets @v to @i and returns old @v
+ */
+static inline long long atomic64_xchg(atomic64_t *v, long long n)
+{
+	return xchg64(&v->counter, n);
+}
+
+/**
+ * atomic64_cmpxchg - atomically exchange contents of memory if it matches
+ * @v: pointer of type atomic64_t
+ * @o: old value that memory should have
+ * @n: new value to write to memory if it matches
+ *
+ * Atomically checks if @v holds @o and replaces it with @n if so.
+ * Returns the old value at @v.
+ */
+static inline long long atomic64_cmpxchg(atomic64_t *v, long long o,
+					long long n)
+{
+	return cmpxchg64(&v->counter, o, n);
+}
+
+static inline long long atomic64_dec_if_positive(atomic64_t *v)
+{
+	long long c, old, dec;
+
+	c = atomic64_read(v);
+	for (;;) {
+		dec = c - 1;
+		if (unlikely(dec < 0))
+			break;
+		old = atomic64_cmpxchg((v), c, dec);
+		if (likely(old == c))
+			break;
+		c = old;
+	}
+	return dec;
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_TILE_ATOMIC_H */