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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
+
+#ifndef __ASSEMBLY__
+
+#include <linux/compiler.h>
+#include <asm/system.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 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_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)
+
+/**
+ * atomic_inc_not_zero - increment unless the number is zero
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1, so long as @v is non-zero.
+ * Returns non-zero if @v was non-zero, and zero otherwise.
+ */
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
+
+/*
+ * We define xchg() and cmpxchg() in the included headers.
+ * Note that we do not define __HAVE_ARCH_CMPXCHG, since that would imply
+ * that cmpxchg() is an efficient operation, which is not particularly true.
+ */
+
+/* Nonexistent functions intended to cause link errors. */
+extern unsigned long __xchg_called_with_bad_pointer(void);
+extern unsigned long __cmpxchg_called_with_bad_pointer(void);
+
+#define tas(ptr) (xchg((ptr), 1))
+
+#endif /* __ASSEMBLY__ */
+
+#ifndef __tilegx__
+#include <asm/atomic_32.h>
+#else
+#include <asm/atomic_64.h>
+#endif
+
+/* Provide the appropriate atomic_long_t definitions. */
+#ifndef __ASSEMBLY__
+#include <asm-generic/atomic-long.h>
+#endif
+
+#endif /* _ASM_TILE_ATOMIC_H */