summaryrefslogtreecommitdiffstats
path: root/include/asm-sh64/atomic.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-sh64/atomic.h')
-rw-r--r--include/asm-sh64/atomic.h126
1 files changed, 126 insertions, 0 deletions
diff --git a/include/asm-sh64/atomic.h b/include/asm-sh64/atomic.h
new file mode 100644
index 0000000..8c3872d
--- /dev/null
+++ b/include/asm-sh64/atomic.h
@@ -0,0 +1,126 @@
+#ifndef __ASM_SH64_ATOMIC_H
+#define __ASM_SH64_ATOMIC_H
+
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * include/asm-sh64/atomic.h
+ *
+ * Copyright (C) 2000, 2001 Paolo Alberelli
+ * Copyright (C) 2003 Paul Mundt
+ *
+ */
+
+/*
+ * Atomic operations that C can't guarantee us. Useful for
+ * resource counting etc..
+ *
+ */
+
+typedef struct { volatile int counter; } atomic_t;
+
+#define ATOMIC_INIT(i) ( (atomic_t) { (i) } )
+
+#define atomic_read(v) ((v)->counter)
+#define atomic_set(v,i) ((v)->counter = (i))
+
+#include <asm/system.h>
+
+/*
+ * To get proper branch prediction for the main line, we must branch
+ * forward to code at the end of this object's .text section, then
+ * branch back to restart the operation.
+ */
+
+static __inline__ void atomic_add(int i, atomic_t * v)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *(long *)v += i;
+ local_irq_restore(flags);
+}
+
+static __inline__ void atomic_sub(int i, atomic_t *v)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *(long *)v -= i;
+ local_irq_restore(flags);
+}
+
+static __inline__ int atomic_add_return(int i, atomic_t * v)
+{
+ unsigned long temp, flags;
+
+ local_irq_save(flags);
+ temp = *(long *)v;
+ temp += i;
+ *(long *)v = temp;
+ local_irq_restore(flags);
+
+ return temp;
+}
+
+#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
+
+static __inline__ int atomic_sub_return(int i, atomic_t * v)
+{
+ unsigned long temp, flags;
+
+ local_irq_save(flags);
+ temp = *(long *)v;
+ temp -= i;
+ *(long *)v = temp;
+ local_irq_restore(flags);
+
+ return temp;
+}
+
+#define atomic_dec_return(v) atomic_sub_return(1,(v))
+#define atomic_inc_return(v) atomic_add_return(1,(v))
+
+/*
+ * 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 zero, or false for all
+ * other cases.
+ */
+#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
+
+#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(v) atomic_add(1,(v))
+#define atomic_dec(v) atomic_sub(1,(v))
+
+static __inline__ void atomic_clear_mask(unsigned int mask, atomic_t *v)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *(long *)v &= ~mask;
+ local_irq_restore(flags);
+}
+
+static __inline__ void atomic_set_mask(unsigned int mask, atomic_t *v)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ *(long *)v |= mask;
+ local_irq_restore(flags);
+}
+
+/* Atomic operations are already serializing on SH */
+#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()
+
+#endif /* __ASM_SH64_ATOMIC_H */
OpenPOWER on IntegriCloud