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authorDavid S. Miller <davem@davemloft.net>2009-04-16 17:35:26 -0700
committerDavid S. Miller <davem@davemloft.net>2009-04-16 17:35:26 -0700
commita54bfa40fd16aeb90bc556189221576f746f8567 (patch)
tree176bb7a99ffab5f42f0dd4e9671f335be3f3efa0 /arch/mn10300/include/asm/atomic.h
parentfe957c40ec5e2763b9977c565beab3bde3aaf85b (diff)
parent134ffb4cad92a6aa534e55a9be145bca780a32c1 (diff)
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Diffstat (limited to 'arch/mn10300/include/asm/atomic.h')
-rw-r--r--arch/mn10300/include/asm/atomic.h157
1 files changed, 157 insertions, 0 deletions
diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h
new file mode 100644
index 00000000000..bc064825f9b
--- /dev/null
+++ b/arch/mn10300/include/asm/atomic.h
@@ -0,0 +1,157 @@
+/* MN10300 Atomic counter operations
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef _ASM_ATOMIC_H
+#define _ASM_ATOMIC_H
+
+#ifdef CONFIG_SMP
+#error not SMP safe
+#endif
+
+/*
+ * Atomic operations that C can't guarantee us. Useful for
+ * resource counting etc..
+ */
+
+#define ATOMIC_INIT(i) { (i) }
+
+#ifdef __KERNEL__
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v. Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_read(v) ((v)->counter)
+
+/**
+ * atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i. Note that the guaranteed
+ * useful range of an atomic_t is only 24 bits.
+ */
+#define atomic_set(v, i) (((v)->counter) = (i))
+
+#include <asm/system.h>
+
+/**
+ * atomic_add_return - add integer to atomic variable
+ * @i: integer value to add
+ * @v: pointer of type atomic_t
+ *
+ * Atomically adds @i to @v and returns the result
+ * Note that the guaranteed useful range of an atomic_t is only 24 bits.
+ */
+static inline int atomic_add_return(int i, atomic_t *v)
+{
+ unsigned long flags;
+ int temp;
+
+ local_irq_save(flags);
+ temp = v->counter;
+ temp += i;
+ v->counter = temp;
+ local_irq_restore(flags);
+
+ return temp;
+}
+
+/**
+ * atomic_sub_return - subtract integer from atomic variable
+ * @i: integer value to subtract
+ * @v: pointer of type atomic_t
+ *
+ * Atomically subtracts @i from @v and returns the result
+ * Note that the guaranteed useful range of an atomic_t is only 24 bits.
+ */
+static inline int atomic_sub_return(int i, atomic_t *v)
+{
+ unsigned long flags;
+ int temp;
+
+ local_irq_save(flags);
+ temp = v->counter;
+ temp -= i;
+ v->counter = temp;
+ local_irq_restore(flags);
+
+ return temp;
+}
+
+static inline int atomic_add_negative(int i, atomic_t *v)
+{
+ return atomic_add_return(i, v) < 0;
+}
+
+static inline void atomic_add(int i, atomic_t *v)
+{
+ atomic_add_return(i, v);
+}
+
+static inline void atomic_sub(int i, atomic_t *v)
+{
+ atomic_sub_return(i, v);
+}
+
+static inline void atomic_inc(atomic_t *v)
+{
+ atomic_add_return(1, v);
+}
+
+static inline void atomic_dec(atomic_t *v)
+{
+ atomic_sub_return(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_dec_and_test(v) (atomic_sub_return(1, (v)) == 0)
+#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0)
+
+#define atomic_add_unless(v, a, u) \
+({ \
+ int c, old; \
+ c = atomic_read(v); \
+ while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
+ c = old; \
+ c != (u); \
+})
+
+#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
+
+static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
+{
+ unsigned long flags;
+
+ mask = ~mask;
+ local_irq_save(flags);
+ *addr &= mask;
+ local_irq_restore(flags);
+}
+
+#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v)))
+#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new)))
+
+/* Atomic operations are already serializing on MN10300??? */
+#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 /* __KERNEL__ */
+#endif /* _ASM_ATOMIC_H */