patch-2.2.18 linux/include/asm-sparc64/system.h

• Lines: 70
• Date: Sun Sep 10 14:49:10 2000
• Orig file: v2.2.17/include/asm-sparc64/system.h
• Orig date: Fri Apr 21 12:46:52 2000

diff -u --new-file --recursive --exclude-from /usr/src/exclude v2.2.17/include/asm-sparc64/system.h linux/include/asm-sparc64/system.h
@@ -1,4 +1,4 @@
-/* $Id: system.h,v 1.50.2.1 2000/03/06 22:30:28 davem Exp $ */
+/* $Id: system.h,v 1.50.2.2 2000/09/05 00:10:58 davem Exp $ */
 #ifndef __SPARC64_SYSTEM_H
 #define __SPARC64_SYSTEM_H
 
@@ -252,6 +252,63 @@
 }
 
 extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
+
+/* 
+ * Atomic compare and exchange.  Compare OLD with MEM, if identical,
+ * store NEW in MEM.  Return the initial value in MEM.  Success is
+ * indicated by comparing RETURN with OLD.
+ */
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+extern __inline__ unsigned long
+__cmpxchg_u32(volatile int *m, int old, int new)
+{
+	__asm__ __volatile__("cas [%2], %3, %0\n\t"
+			     "membar #StoreStore | #StoreLoad"
+			     : "=&r" (new)
+			     : "0" (new), "r" (m), "r" (old)
+			     : "memory");
+
+	return new;
+}
+
+extern __inline__ unsigned long
+__cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
+{
+	__asm__ __volatile__("casx [%2], %3, %0\n\t"
+			     "membar #StoreStore | #StoreLoad"
+			     : "=&r" (new)
+			     : "0" (new), "r" (m), "r" (old)
+			     : "memory");
+
+	return new;
+}
+
+/* This function doesn't exist, so you'll get a linker error
+   if something tries to do an invalid cmpxchg().  */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+static __inline__ unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
+{
+	switch (size) {
+		case 4:
+			return __cmpxchg_u32(ptr, old, new);
+		case 8:
+			return __cmpxchg_u64(ptr, old, new);
+	}
+	__cmpxchg_called_with_bad_pointer();
+	return old;
+}
+
+#define cmpxchg(ptr,o,n)						 \
+  ({									 \
+     __typeof__(*(ptr)) _o_ = (o);					 \
+     __typeof__(*(ptr)) _n_ = (n);					 \
+     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
+				    (unsigned long)_n_, sizeof(*(ptr))); \
+  })
 
 #endif /* !(__ASSEMBLY__) */