From 8af575091284bb94eb10f0534ef2cdd6cc21df2c Mon Sep 17 00:00:00 2001
From: Jan Blunck <jblunck@suse.de>
Date: Tue, 6 Oct 2009 12:31:41 +0200
Subject: [PATCH] s390: Add uatomic_set(), uatomic_read(), uatomic_add(),
 uatomic_cmpxchg()

Mathieu needs atomic cmpxchg and add for all architectures.

Signed-off-by: Jan Blunck <jblunck@suse.de>
---
 urcu/arch_uatomic_s390.h | 121 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/urcu/arch_uatomic_s390.h b/urcu/arch_uatomic_s390.h
index c289c74..917dbf2 100644
--- a/urcu/arch_uatomic_s390.h
+++ b/urcu/arch_uatomic_s390.h
@@ -40,6 +40,13 @@
 #define BITS_PER_LONG	(__SIZEOF_LONG__ * 8)
 #endif
 
+#define uatomic_set(addr, v)				\
+do {							\
+	ACCESS_ONCE(*(addr)) = (v);			\
+} while (0)
+
+#define uatomic_read(addr)	ACCESS_ONCE(*(addr))
+
 static inline __attribute__((always_inline))
 unsigned int uatomic_exchange_32(volatile unsigned int *addr, unsigned int val)
 {
@@ -96,4 +103,118 @@ unsigned long _uatomic_exchange(volatile void *addr, unsigned long val, int len)
 	(__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
 					       sizeof(*(addr)))
 
+
+static inline __attribute__((always_inline))
+void uatomic_add_32(volatile unsigned int *addr, unsigned int val)
+{
+	unsigned int result, old;
+
+	__asm__ __volatile__(
+		"	l %0, %1\n"
+		"0:	lr %2, %0\n"
+		"	ar %2, %3\n"
+		"	cs %0,%2,%1\n"
+		"	brc 4,0b\n"
+		: "=&r"(old), "+m" (*addr),
+		  "=&r"(result)
+		: "r"(val)
+		: "memory", "cc");
+}
+
+#if (BITS_PER_LONG == 64)
+
+static inline __attribute__((always_inline))
+void uatomic_add_64(volatile unsigned long *addr, unsigned long val)
+{
+	unsigned long result, old;
+
+	__asm__ __volatile__(
+		"	lg %0, %1\n"
+		"0:	lgr %2, %0\n"
+		"	agr %2, %3\n"
+		"	csg %0,%2,%1\n"
+		"	brc 4,0b\n"
+		: "=&r"(old), "+m" (*addr),
+		  "=&r"(result)
+		: "r"(val)
+		: "memory", "cc");
+}
+
+#endif
+
+static inline __attribute__((always_inline))
+void _uatomic_add(void *addr, unsigned long val, int len)
+{
+	switch (len) {
+	case 4:
+		uatomic_add_32(addr, val);
+		return;
+#if (BITS_PER_LONG == 64)
+	case 8:
+		uatomic_add_64(addr, val);
+		return;
+#endif
+	default:
+		__asm__ __volatile__(".long	0xd00d00");
+	}
+
+	return;
+}
+
+#define uatomic_add(addr, val)						\
+	_uatomic_add((addr), (unsigned long)(val), sizeof(*(addr)))
+
+static inline __attribute__((always_inline))
+unsigned int uatomic_cmpxchg_32(volatile unsigned int *addr, unsigned int old,
+				unsigned int new)
+{
+	__asm__ __volatile__(
+		"	cs %0,%2,%1\n"
+		: "+r"(old), "+m"(*addr)
+		: "r"(new)
+		: "memory", "cc");
+
+	return old;
+}
+
+#if (BITS_PER_LONG == 64)
+
+static inline __attribute__((always_inline))
+unsigned long uatomic_cmpxchg_64(volatile unsigned long *addr,
+				 unsigned long old, unsigned long new)
+{
+	__asm__ __volatile__(
+		"	csg %0,%2,%1\n"
+		: "+r"(old), "+m"(*addr)
+		: "r"(new)
+		: "memory", "cc");
+
+	return old;
+}
+
+#endif
+
+unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
+			       unsigned long new, int len)
+{
+	switch (len) {
+	case 4:
+		return uatomic_cmpxchg_32(addr, old, new);
+#if (BITS_PER_LONG == 64)
+	case 8:
+		return uatomic_cmpxchg_64(addr, old, new);
+#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)))
+
 #endif /* _URCU_ARCH_ATOMIC_S390_H */
-- 
2.34.1