patch-1.3.77 linux/include/asm-alpha/atomic.h

• Lines: 54
• Date: Wed Mar 20 15:00:13 1996
• Orig file: v1.3.76/linux/include/asm-alpha/atomic.h
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.76/linux/include/asm-alpha/atomic.h linux/include/asm-alpha/atomic.h
@@ -0,0 +1,53 @@
+#ifndef __ARCH_I386_ATOMIC__
+#define __ARCH_I386_ATOMIC__
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc..
+ */
+
+/*
+ * 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)
+
+typedef int atomic_t;
+
+extern __inline__ void atomic_add(atomic_t i, atomic_t * v)
+{
+	unsigned long temp;
+	__asm__ __volatile__(
+		"\n1:\t"
+		"ldl_l %0,%1\n\t"
+		"addl %0,%2,%0\n\t"
+		"stl_c %0,%1\n\t"
+		"beq %0,1b\n"
+		"2:"
+		:"=&r" (temp),
+		 "=m" (__atomic_fool_gcc(v))
+		:"Ir" (i),
+		 "m" (__atomic_fool_gcc(v)));
+}
+
+extern __inline__ void atomic_sub(atomic_t i, atomic_t * v)
+{
+	unsigned long temp;
+	__asm__ __volatile__(
+		"\n1:\t"
+		"ldl_l %0,%1\n\t"
+		"subl %0,%2,%0\n\t"
+		"stl_c %0,%1\n\t"
+		"beq %0,1b\n"
+		"2:"
+		:"=&r" (temp),
+		 "=m" (__atomic_fool_gcc(v))
+		:"Ir" (i),
+		 "m" (__atomic_fool_gcc(v)));
+}
+
+#define atomic_inc(v) atomic_add(1,(v))
+#define atomic_dec(v) atomic_sub(1,(v))
+
+#endif