1 files changed, 201 insertions, 0 deletions
diff --git a/include/asm-avr32/atomic.h b/include/asm-avr32/atomic.h
new file mode 100644
index 0000000..e0b9c44
--- /dev/null
+++ b/include/asm-avr32/atomic.h
@@ -0,0 +1,201 @@
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc.
+ *
+ * But use these as seldom as possible since they are slower than
+ * regular operations.
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __ASM_AVR32_ATOMIC_H
+#define __ASM_AVR32_ATOMIC_H
+
+#include <asm/system.h>
+
+typedef struct { volatile int counter; } atomic_t;
+#define ATOMIC_INIT(i)  { (i) }
+
+#define atomic_read(v)		((v)->counter)
+#define atomic_set(v, i)	(((v)->counter) = i)
+
+/*
+ * atomic_sub_return - subtract the atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v. Returns the resulting value.
+ */
+static inline int atomic_sub_return(int i, atomic_t *v)
+{
+	int result;
+
+	asm volatile(
+		"/* atomic_sub_return */\n"
+		"1:	ssrf	5\n"
+		"	ld.w	%0, %2\n"
+		"	sub	%0, %3\n"
+		"	stcond	%1, %0\n"
+		"	brne	1b"
+		: "=&r"(result), "=o"(v->counter)
+		: "m"(v->counter), "ir"(i)
+		: "cc");
+
+	return result;
+}
+
+/*
+ * atomic_add_return - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v. Returns the resulting value.
+ */
+static inline int atomic_add_return(int i, atomic_t *v)
+{
+	int result;
+
+	if (__builtin_constant_p(i))
+		result = atomic_sub_return(-i, v);
+	else
+		asm volatile(
+			"/* atomic_add_return */\n"
+			"1:	ssrf	5\n"
+			"	ld.w	%0, %1\n"
+			"	add	%0, %3\n"
+			"	stcond	%2, %0\n"
+			"	brne	1b"
+			: "=&r"(result), "=o"(v->counter)
+			: "m"(v->counter), "r"(i)
+			: "cc", "memory");
+
+	return result;
+}
+
+/*
+ * atomic_sub_unless - sub unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * If the atomic value v is not equal to u, this function subtracts a
+ * from v, and returns non zero. If v is equal to u then it returns
+ * zero. This is done as an atomic operation.
+*/
+static inline int atomic_sub_unless(atomic_t *v, int a, int u)
+{
+	int tmp, result = 0;
+
+	asm volatile(
+		"/* atomic_sub_unless */\n"
+		"1:	ssrf	5\n"
+		"	ld.w	%0, %3\n"
+		"	cp.w	%0, %5\n"
+		"	breq	1f\n"
+		"	sub	%0, %4\n"
+		"	stcond	%2, %0\n"
+		"	brne	1b\n"
+		"	mov	%1, 1\n"
+		"1:"
+		: "=&r"(tmp), "=&r"(result), "=o"(v->counter)
+		: "m"(v->counter), "ir"(a), "ir"(u)
+		: "cc", "memory");
+
+	return result;
+}
+
+/*
+ * atomic_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * If the atomic value v is not equal to u, this function adds a to v,
+ * and returns non zero. If v is equal to u then it returns zero. This
+ * is done as an atomic operation.
+*/
+static inline int atomic_add_unless(atomic_t *v, int a, int u)
+{
+	int tmp, result;
+
+	if (__builtin_constant_p(a))
+		result = atomic_sub_unless(v, -a, u);
+	else {
+		result = 0;
+		asm volatile(
+			"/* atomic_add_unless */\n"
+			"1:	ssrf	5\n"
+			"	ld.w	%0, %3\n"
+			"	cp.w	%0, %5\n"
+			"	breq	1f\n"
+			"	add	%0, %4\n"
+			"	stcond	%2, %0\n"
+			"	brne	1b\n"
+			"	mov	%1, 1\n"
+			"1:"
+			: "=&r"(tmp), "=&r"(result), "=o"(v->counter)
+			: "m"(v->counter), "r"(a), "ir"(u)
+			: "cc", "memory");
+	}
+
+	return result;
+}
+
+/*
+ * atomic_sub_if_positive - conditionally subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically test @v and subtract @i if @v is greater or equal than @i.
+ * The function returns the old value of @v minus @i.
+ */
+static inline int atomic_sub_if_positive(int i, atomic_t *v)
+{
+	int result;
+
+	asm volatile(
+		"/* atomic_sub_if_positive */\n"
+		"1:	ssrf	5\n"
+		"	ld.w	%0, %2\n"
+		"	sub	%0, %3\n"
+		"	brlt	1f\n"
+		"	stcond	%1, %0\n"
+		"	brne	1b\n"
+		"1:"
+		: "=&r"(result), "=o"(v->counter)
+		: "m"(v->counter), "ir"(i)
+		: "cc", "memory");
+
+	return result;
+}
+
+#define atomic_xchg(v, new)	(xchg(&((v)->counter), new))
+#define atomic_cmpxchg(v, o, n)	((int)cmpxchg(&((v)->counter), (o), (n)))
+
+#define atomic_sub(i, v)	(void)atomic_sub_return(i, v)
+#define atomic_add(i, v)	(void)atomic_add_return(i, v)
+#define atomic_dec(v)		atomic_sub(1, (v))
+#define atomic_inc(v)		atomic_add(1, (v))
+
+#define atomic_dec_return(v)	atomic_sub_return(1, v)
+#define atomic_inc_return(v)	atomic_add_return(1, v)
+
+#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
+#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
+#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
+#define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0)
+
+#define atomic_inc_not_zero(v)	atomic_add_unless(v, 1, 0)
+#define atomic_dec_if_positive(v) atomic_sub_if_positive(1, v)
+
+#define smp_mb__before_atomic_dec()	barrier()
+#define smp_mb__after_atomic_dec()	barrier()
+#define smp_mb__before_atomic_inc()	barrier()
+#define smp_mb__after_atomic_inc()	barrier()
+
+#include <asm-generic/atomic.h>
+
+#endif /*  __ASM_AVR32_ATOMIC_H */