patch-2.3.16 linux/include/asm-sh/atomic.h

• Lines: 114
• Date: Mon Aug 30 18:12:59 1999
• Orig file: v2.3.15/linux/include/asm-sh/atomic.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.15/linux/include/asm-sh/atomic.h linux/include/asm-sh/atomic.h
@@ -0,0 +1,113 @@
+#ifndef __ASM_SH_ATOMIC_H
+#define __ASM_SH_ATOMIC_H
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc..
+ *
+ */
+
+#ifdef __SMP__
+typedef struct { volatile int counter; } atomic_t;
+#else
+typedef struct { int counter; } atomic_t;
+#endif
+
+#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>
+
+/*
+ * Make sure gcc doesn't try to be clever and move things around
+ * on us. We need to use _exactly_ the address the user gave us,
+ * not some alias that contains the same information.
+ */
+#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
+
+/*
+ * 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.
+ */
+
+extern __inline__ void atomic_add(int i, atomic_t * v)
+{
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+	*(long *)v += i;
+	restore_flags(flags);
+}
+
+extern __inline__ void atomic_sub(int i, atomic_t *v)
+{
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+	*(long *)v -= i;
+	restore_flags(flags);
+}
+
+extern __inline__ int atomic_add_return(int i, atomic_t * v)
+{
+	unsigned long temp, flags;
+
+	save_flags(flags);
+	cli();
+	temp = *(long *)v;
+	temp += i;
+	*(long *)v = temp;
+	restore_flags(flags);
+
+	return temp;
+}
+
+extern __inline__ int atomic_sub_return(int i, atomic_t * v)
+{
+	unsigned long temp, flags;
+
+	save_flags(flags);
+	cli();
+	temp = *(long *)v;
+	temp -= i;
+	*(long *)v = temp;
+	restore_flags(flags);
+
+	return temp;
+}
+
+#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(v) atomic_add(1,(v))
+#define atomic_dec(v) atomic_sub(1,(v))
+
+extern __inline__ void atomic_clear_mask(int mask, atomic_t *v)
+{
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+	*(long *)v &= ~mask;
+	restore_flags(flags);
+}
+
+extern __inline__ void atomic_set_mask(int mask, atomic_t *v)
+{
+	unsigned long flags;
+
+	save_flags(flags);
+	cli();
+	*(long *)v |= mask;
+	restore_flags(flags);
+}
+
+#endif /* __ASM_SH_ATOMIC_H */