Add extern "C" to support linking userspace RCU library with C++ applications

[urcu.git] / urcu / uatomic_arch_s390.h

diff --git a/urcu/uatomic_arch_s390.h b/urcu/uatomic_arch_s390.h
index a8c8706e7b10c372ffe065394772b3c5089edbcb..813d9708a8efff783938a24c3e55987c64042436 100644 (file)
--- a/urcu/uatomic_arch_s390.h
+++ b/urcu/uatomic_arch_s390.h
@@ -32,6 +32,10 @@
 #include <urcu/compiler.h>
 #include <urcu/system.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif 
+
 #ifndef __SIZEOF_LONG__
 #ifdef __s390x__
 #define __SIZEOF_LONG__ 8
@@ -44,6 +48,36 @@
 #define BITS_PER_LONG  (__SIZEOF_LONG__ * 8)
 #endif
 
+#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
+#define COMPILER_HAVE_SHORT_MEM_OPERAND
+#endif
+
+/*
+ * MEMOP assembler operand rules:
+ * - op refer to MEMOP_IN operand
+ * - MEMOP_IN can expand to more than a single operand. Use it at the end of
+ *   operand list only.
+ */
+
+#ifdef COMPILER_HAVE_SHORT_MEM_OPERAND
+
+#define MEMOP_OUT(addr)        "=Q" (*(addr))
+#define MEMOP_IN       "Q" (*(addr))
+#define MEMOP_REF(op)  #op             /* op refer to MEMOP_IN operand */
+
+#else /* !COMPILER_HAVE_SHORT_MEM_OPERAND */
+
+#define MEMOP_OUT(addr)        "=m" (*(addr))
+#define MEMOP_IN       "a" (addr), "m" (*(addr))
+#define MEMOP_REF(op)  "0(" #op ")"    /* op refer to MEMOP_IN operand */
+
+#endif /* !COMPILER_HAVE_SHORT_MEM_OPERAND */
+
+struct __uatomic_dummy {
+       unsigned long v[10];
+};
+#define __hp(x)        ((struct __uatomic_dummy *)(x))
+
 #define uatomic_set(addr, v)   STORE_SHARED(*(addr), (v))
 #define uatomic_read(addr)     LOAD_SHARED(*(addr))
 
@@ -58,10 +92,10 @@ unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
                unsigned int old_val;
 
                __asm__ __volatile__(
-                       "0:     cs %0,%2,%1\n"
+                       "0:     cs %0,%2," MEMOP_REF(%3) "\n"
                        "       brc 4,0b\n"
-                       : "=&r"(old_val), "=m" (*addr)
-                       : "r"(val), "m" (*addr)
+                       : "=&r" (old_val), MEMOP_OUT (__hp(addr))
+                       : "r" (val), MEMOP_IN (__hp(addr))
                        : "memory", "cc");
                return old_val;
        }
@@ -71,10 +105,10 @@ unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
                unsigned long old_val;
 
                __asm__ __volatile__(
-                       "0:     csg %0,%2,%1\n"
+                       "0:     csg %0,%2," MEMOP_REF(%3) "\n"
                        "       brc 4,0b\n"
-                       : "=&r"(old_val), "=m" (*addr)
-                       : "r"(val), "m" (*addr)
+                       : "=&r" (old_val), MEMOP_OUT (__hp(addr))
+                       : "r" (val), MEMOP_IN (__hp(addr))
                        : "memory", "cc");
                return old_val;
        }
@@ -102,9 +136,9 @@ unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
                unsigned int old_val = (unsigned int)old;
 
                __asm__ __volatile__(
-                       "       cs %0,%2,%1\n"
-                       : "+r"(old_val), "+m"(*addr)
-                       : "r"(_new)
+                       "       cs %0,%2," MEMOP_REF(%3) "\n"
+                       : "+r" (old_val), MEMOP_OUT (__hp(addr))
+                       : "r" (_new), MEMOP_IN (__hp(addr))
                        : "memory", "cc");
                return old_val;
        }
@@ -112,9 +146,9 @@ unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
        case 8:
        {
                __asm__ __volatile__(
-                       "       csg %0,%2,%1\n"
-                       : "+r"(old), "+m"(*addr)
-                       : "r"(_new)
+                       "       csg %0,%2," MEMOP_REF(%3) "\n"
+                       : "+r" (old), MEMOP_OUT (__hp(addr))
+                       : "r" (_new), MEMOP_IN (__hp(addr))
                        : "memory", "cc");
                return old;
        }
@@ -186,4 +220,8 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
 
 #define compat_uatomic_cmpxchg(ptr, old, _new) uatomic_cmpxchg(ptr, old, _new)
 
+#ifdef __cplusplus 
+}
+#endif
+
 #endif /* _URCU_UATOMIC_ARCH_S390_H */