+#ifndef _URCU_UATOMIC_ARCH_S390_H
+#define _URCU_UATOMIC_ARCH_S390_H
+
+/*
+ * Atomic exchange operations for the S390 architecture. Based on information
+ * taken from the Principles of Operation Appendix A "Conditional Swapping
+ * Instructions (CS, CDS)".
+ *
+ * Copyright (c) 2009 Novell, Inc.
+ * Author: Jan Blunck <jblunck@suse.de>
+ * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <urcu/compiler.h>
+#include <urcu/system.h>
+
+#ifdef __cplusplus
+extern "C" {
+#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(addr) "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(addr) "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))
+
+/* xchg */
+
+static inline __attribute__((always_inline))
+unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
+{
+ switch (len) {
+ case 4:
+ {
+ unsigned int old_val;
+
+ __asm__ __volatile__(
+ "0: cs %0,%2," MEMOP_REF(%3) "\n"
+ " brc 4,0b\n"
+ : "=&r" (old_val), MEMOP_OUT (__hp(addr))
+ : "r" (val), MEMOP_IN (__hp(addr))
+ : "memory", "cc");
+ return old_val;
+ }
+#if (CAA_BITS_PER_LONG == 64)
+ case 8:
+ {
+ unsigned long old_val;
+
+ __asm__ __volatile__(
+ "0: csg %0,%2," MEMOP_REF(%3) "\n"
+ " brc 4,0b\n"
+ : "=&r" (old_val), MEMOP_OUT (__hp(addr))
+ : "r" (val), MEMOP_IN (__hp(addr))
+ : "memory", "cc");
+ return old_val;
+ }
+#endif
+ default:
+ __asm__ __volatile__(".long 0xd00d00");
+ }
+
+ return 0;
+}
+
+#define uatomic_xchg(addr, v) \
+ (__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
+ sizeof(*(addr)))
+
+/* cmpxchg */
+
+static inline __attribute__((always_inline))
+unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
+ unsigned long _new, int len)
+{
+ switch (len) {
+ case 4:
+ {
+ unsigned int old_val = (unsigned int)old;
+
+ __asm__ __volatile__(
+ " 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;
+ }
+#if (CAA_BITS_PER_LONG == 64)
+ case 8:
+ {
+ __asm__ __volatile__(
+ " csg %0,%2," MEMOP_REF(%3) "\n"
+ : "+r" (old), MEMOP_OUT (__hp(addr))
+ : "r" (_new), MEMOP_IN (__hp(addr))
+ : "memory", "cc");
+ return old;
+ }
+#endif
+ default:
+ __asm__ __volatile__(".long 0xd00d00");
+ }
+
+ return 0;
+}
+
+#define uatomic_cmpxchg(addr, old, _new) \
+ (__typeof__(*(addr))) _uatomic_cmpxchg((addr), \
+ (unsigned long)(old), \
+ (unsigned long)(_new), \
+ sizeof(*(addr)))
+
+#ifdef __cplusplus
+}
+#endif
+
+#include <urcu/uatomic/generic.h>
+
+#endif /* _URCU_UATOMIC_ARCH_S390_H */