patch-1.3.84 linux/include/asm-alpha/atomic.h

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diff -u --recursive --new-file v1.3.83/linux/include/asm-alpha/atomic.h linux/include/asm-alpha/atomic.h
@@ -50,7 +50,30 @@
 		 "m" (__atomic_fool_gcc(v)));
 }
 
+/*
+ * Same as above, but return true if we counted down to zero
+ */
+extern __inline__ int atomic_sub_and_test(atomic_t i, atomic_t * v)
+{
+	unsigned long temp, result;
+	__asm__ __volatile__(
+		"\n1:\t"
+		"ldl_l %0,%1\n\t"
+		"subl %0,%3,%0\n\t"
+		"bis %0,%0,%2\n\t"
+		"stl_c %0,%1\n\t"
+		"beq %0,1b\n"
+		"2:"
+		:"=&r" (temp),
+		 "=m" (__atomic_fool_gcc(v)),
+		 "=&r" (result)
+		:"Ir" (i),
+		 "m" (__atomic_fool_gcc(v)));
+	return result==0;
+}
+
 #define atomic_inc(v) atomic_add(1,(v))
 #define atomic_dec(v) atomic_sub(1,(v))
+#define atomic_dec_and_test(v) atomic_sub_and_test(1,(v))
 
 #endif

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