From f469d83969772a24539eaa24430bc73347a882a3 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon, 1 Mar 2010 14:00:22 -0500
Subject: [PATCH] move whether atomic byte/short exists to uatomic_arch_*.h

And add more generic implementations to uatomic_defaults.h.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tests/test_uatomic.c    | 15 +------
 urcu/uatomic_arch_x86.h |  3 ++
 urcu/uatomic_generic.h  | 96 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 101 insertions(+), 13 deletions(-)

diff --git a/tests/test_uatomic.c b/tests/test_uatomic.c
index c0f36fe..5682655 100644
--- a/tests/test_uatomic.c
+++ b/tests/test_uatomic.c
@@ -1,21 +1,10 @@
 #include <stdio.h>
 #include <assert.h>
-
-#define UATOMIC_NO_LINK_ERROR
 #include <urcu/uatomic_arch.h>
 
-#if (defined(__i386__) || defined(__x86_64__))
-#define HAS_ATOMIC_BYTE
-#define HAS_ATOMIC_SHORT
-#endif
-
 struct testvals {
-#ifdef HAS_ATOMIC_BYTE
 	unsigned char c;
-#endif
-#ifdef HAS_ATOMIC_SHORT
 	unsigned short s;
-#endif
 	unsigned int i;
 	unsigned long l;
 };
@@ -54,10 +43,10 @@ do {						\
 
 int main(int argc, char **argv)
 {
-#ifdef HAS_ATOMIC_BYTE
+#ifdef UATOMIC_HAS_ATOMIC_BYTE
 	do_test(&vals.c);
 #endif
-#ifdef HAS_ATOMIC_SHORT
+#ifdef UATOMIC_HAS_ATOMIC_SHORT
 	do_test(&vals.s);
 #endif
 	do_test(&vals.i);
diff --git a/urcu/uatomic_arch_x86.h b/urcu/uatomic_arch_x86.h
index e358be3..666e498 100644
--- a/urcu/uatomic_arch_x86.h
+++ b/urcu/uatomic_arch_x86.h
@@ -23,6 +23,9 @@
 #include <urcu/compiler.h>
 #include <urcu/system.h>
 
+#define UATOMIC_HAS_ATOMIC_BYTE
+#define UATOMIC_HAS_ATOMIC_SHORT
+
 #ifdef __cplusplus
 extern "C" {
 #endif 
diff --git a/urcu/uatomic_generic.h b/urcu/uatomic_generic.h
index 6e2c23e..9ee7b7b 100644
--- a/urcu/uatomic_generic.h
+++ b/urcu/uatomic_generic.h
@@ -65,6 +65,14 @@ unsigned long _uatomic_cmpxchg(void *addr, unsigned long old,
 			      unsigned long _new, int len)
 {
 	switch (len) {
+#ifdef UATOMIC_HAS_ATOMIC_BYTE
+	case 1:
+		return __sync_val_compare_and_swap_1(addr, old, _new);
+#endif
+#ifdef UATOMIC_HAS_ATOMIC_SHORT
+	case 2:
+		return __sync_val_compare_and_swap_2(addr, old, _new);
+#endif
 	case 4:
 		return __sync_val_compare_and_swap_4(addr, old, _new);
 #if (BITS_PER_LONG == 64)
@@ -91,6 +99,14 @@ unsigned long _uatomic_add_return(void *addr, unsigned long val,
 				 int len)
 {
 	switch (len) {
+#ifdef UATOMIC_HAS_ATOMIC_BYTE
+	case 1:
+		return __sync_add_and_fetch_1(addr, val);
+#endif
+#ifdef UATOMIC_HAS_ATOMIC_SHORT
+	case 2:
+		return __sync_add_and_fetch_2(addr, val);
+#endif
 	case 4:
 		return __sync_add_and_fetch_4(addr, val);
 #if (BITS_PER_LONG == 64)
@@ -116,6 +132,30 @@ static inline __attribute__((always_inline))
 unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
 {
 	switch (len) {
+#ifdef UATOMIC_HAS_ATOMIC_BYTE
+	case 1:
+	{
+		unsigned char old;
+
+		do {
+			old = uatomic_read((unsigned char *)addr);
+		} while (!__sync_bool_compare_and_swap_1(addr, old, val));
+
+		return old;
+	}
+#endif
+#ifdef UATOMIC_HAS_ATOMIC_SHORT
+	case 2:
+	{
+		unsigned short old;
+
+		do {
+			old = uatomic_read((unsigned short *)addr);
+		} while (!__sync_bool_compare_and_swap_2(addr, old, val));
+
+		return old;
+	}
+#endif
 	case 4:
 	{
 		unsigned int old;
@@ -157,6 +197,34 @@ static inline __attribute__((always_inline))
 unsigned long _uatomic_add_return(void *addr, unsigned long val, int len)
 {
 	switch (len) {
+#ifdef UATOMIC_HAS_ATOMIC_BYTE
+	case 1:
+	{
+		unsigned char old, oldt;
+
+		oldt = uatomic_read((unsigned char *)addr);
+		do {
+			old = oldt;
+			oldt = _uatomic_cmpxchg(addr, old, old + val, 1);
+		} while (oldt != old);
+
+		return old + val;
+	}
+#endif
+#ifdef UATOMIC_HAS_ATOMIC_SHORT
+	case 2:
+	{
+		unsigned short old, oldt;
+
+		oldt = uatomic_read((unsigned short *)addr);
+		do {
+			old = oldt;
+			oldt = _uatomic_cmpxchg(addr, old, old + val, 2);
+		} while (oldt != old);
+
+		return old + val;
+	}
+#endif
 	case 4:
 	{
 		unsigned int old, oldt;
@@ -201,6 +269,34 @@ static inline __attribute__((always_inline))
 unsigned long _uatomic_exchange(void *addr, unsigned long val, int len)
 {
 	switch (len) {
+#ifdef UATOMIC_HAS_ATOMIC_BYTE
+	case 1:
+	{
+		unsigned char old, oldt;
+
+		oldt = uatomic_read((unsigned char *)addr);
+		do {
+			old = oldt;
+			oldt = _uatomic_cmpxchg(addr, old, val, 1);
+		} while (oldt != old);
+
+		return old;
+	}
+#endif
+#ifdef UATOMIC_HAS_ATOMIC_SHORT
+	case 2:
+	{
+		unsigned short old, oldt;
+
+		oldt = uatomic_read((unsigned short *)addr);
+		do {
+			old = oldt;
+			oldt = _uatomic_cmpxchg(addr, old, val, 2);
+		} while (oldt != old);
+
+		return old;
+	}
+#endif
 	case 4:
 	{
 		unsigned int old, oldt;
-- 
2.34.1