--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/os_cpu/linux_zero/vm/atomic_linux_zero.inline.hpp	Tue Oct 13 12:04:21 2009 -0700
@@ -0,0 +1,293 @@
+/*
+ * Copyright 2003-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2007, 2008 Red Hat, Inc.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// Implementation of class atomic
+
+#ifdef M68K
+
+/*
+ * __m68k_cmpxchg
+ *
+ * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
+ * Returns newval on success and oldval if no exchange happened.
+ * This implementation is processor specific and works on
+ * 68020 68030 68040 and 68060.
+ *
+ * It will not work on ColdFire, 68000 and 68010 since they lack the CAS
+ * instruction.
+ * Using a kernelhelper would be better for arch complete implementation.
+ *
+ */
+
+static inline int __m68k_cmpxchg(int oldval, int newval, volatile int *ptr) {
+  int ret;
+  __asm __volatile ("cas%.l %0,%2,%1"
+                   : "=d" (ret), "+m" (*(ptr))
+                   : "d" (newval), "0" (oldval));
+  return ret;
+}
+
+/* Perform an atomic compare and swap: if the current value of `*PTR'
+   is OLDVAL, then write NEWVAL into `*PTR'.  Return the contents of
+   `*PTR' before the operation.*/
+static inline int m68k_compare_and_swap(volatile int *ptr,
+                                        int oldval,
+                                        int newval) {
+  for (;;) {
+      int prev = *ptr;
+      if (prev != oldval)
+        return prev;
+
+      if (__m68k_cmpxchg (prev, newval, ptr) == newval)
+        // Success.
+        return prev;
+
+      // We failed even though prev == oldval.  Try again.
+    }
+}
+
+/* Atomically add an int to memory.  */
+static inline int m68k_add_and_fetch(volatile int *ptr, int add_value) {
+  for (;;) {
+      // Loop until success.
+
+      int prev = *ptr;
+
+      if (__m68k_cmpxchg (prev, prev + add_value, ptr) == prev + add_value)
+        return prev + add_value;
+    }
+}
+
+/* Atomically write VALUE into `*PTR' and returns the previous
+   contents of `*PTR'.  */
+static inline int m68k_lock_test_and_set(volatile int *ptr, int newval) {
+  for (;;) {
+      // Loop until success.
+      int prev = *ptr;
+
+      if (__m68k_cmpxchg (prev, newval, ptr) == prev)
+        return prev;
+    }
+}
+#endif // M68K
+
+#ifdef ARM
+
+/*
+ * __kernel_cmpxchg
+ *
+ * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
+ * Return zero if *ptr was changed or non-zero if no exchange happened.
+ * The C flag is also set if *ptr was changed to allow for assembly
+ * optimization in the calling code.
+ *
+ */
+
+typedef int (__kernel_cmpxchg_t)(int oldval, int newval, volatile int *ptr);
+#define __kernel_cmpxchg (*(__kernel_cmpxchg_t *) 0xffff0fc0)
+
+
+
+/* Perform an atomic compare and swap: if the current value of `*PTR'
+   is OLDVAL, then write NEWVAL into `*PTR'.  Return the contents of
+   `*PTR' before the operation.*/
+static inline int arm_compare_and_swap(volatile int *ptr,
+                                       int oldval,
+                                       int newval) {
+  for (;;) {
+      int prev = *ptr;
+      if (prev != oldval)
+        return prev;
+
+      if (__kernel_cmpxchg (prev, newval, ptr) == 0)
+        // Success.
+        return prev;
+
+      // We failed even though prev == oldval.  Try again.
+    }
+}
+
+/* Atomically add an int to memory.  */
+static inline int arm_add_and_fetch(volatile int *ptr, int add_value) {
+  for (;;) {
+      // Loop until a __kernel_cmpxchg succeeds.
+
+      int prev = *ptr;
+
+      if (__kernel_cmpxchg (prev, prev + add_value, ptr) == 0)
+        return prev + add_value;
+    }
+}
+
+/* Atomically write VALUE into `*PTR' and returns the previous
+   contents of `*PTR'.  */
+static inline int arm_lock_test_and_set(volatile int *ptr, int newval) {
+  for (;;) {
+      // Loop until a __kernel_cmpxchg succeeds.
+      int prev = *ptr;
+
+      if (__kernel_cmpxchg (prev, newval, ptr) == 0)
+        return prev;
+    }
+}
+#endif // ARM
+
+inline void Atomic::store(jint store_value, volatile jint* dest) {
+  *dest = store_value;
+}
+
+inline void Atomic::store_ptr(intptr_t store_value, intptr_t* dest) {
+  *dest = store_value;
+}
+
+inline jint Atomic::add(jint add_value, volatile jint* dest) {
+#ifdef ARM
+  return arm_add_and_fetch(dest, add_value);
+#else
+#ifdef M68K
+  return m68k_add_and_fetch(dest, add_value);
+#else
+  return __sync_add_and_fetch(dest, add_value);
+#endif // M68K
+#endif // ARM
+}
+
+inline intptr_t Atomic::add_ptr(intptr_t add_value, volatile intptr_t* dest) {
+#ifdef ARM
+  return arm_add_and_fetch(dest, add_value);
+#else
+#ifdef M68K
+  return m68k_add_and_fetch(dest, add_value);
+#else
+  return __sync_add_and_fetch(dest, add_value);
+#endif // M68K
+#endif // ARM
+}
+
+inline void* Atomic::add_ptr(intptr_t add_value, volatile void* dest) {
+  return (void *) add_ptr(add_value, (volatile intptr_t *) dest);
+}
+
+inline void Atomic::inc(volatile jint* dest) {
+  add(1, dest);
+}
+
+inline void Atomic::inc_ptr(volatile intptr_t* dest) {
+  add_ptr(1, dest);
+}
+
+inline void Atomic::inc_ptr(volatile void* dest) {
+  add_ptr(1, dest);
+}
+
+inline void Atomic::dec(volatile jint* dest) {
+  add(-1, dest);
+}
+
+inline void Atomic::dec_ptr(volatile intptr_t* dest) {
+  add_ptr(-1, dest);
+}
+
+inline void Atomic::dec_ptr(volatile void* dest) {
+  add_ptr(-1, dest);
+}
+
+inline jint Atomic::xchg(jint exchange_value, volatile jint* dest) {
+#ifdef ARM
+  return arm_lock_test_and_set(dest, exchange_value);
+#else
+#ifdef M68K
+  return m68k_lock_test_and_set(dest, exchange_value);
+#else
+  // __sync_lock_test_and_set is a bizarrely named atomic exchange
+  // operation.  Note that some platforms only support this with the
+  // limitation that the only valid value to store is the immediate
+  // constant 1.  There is a test for this in JNI_CreateJavaVM().
+  return __sync_lock_test_and_set (dest, exchange_value);
+#endif // M68K
+#endif // ARM
+}
+
+inline intptr_t Atomic::xchg_ptr(intptr_t exchange_value,
+                                 volatile intptr_t* dest) {
+#ifdef ARM
+  return arm_lock_test_and_set(dest, exchange_value);
+#else
+#ifdef M68K
+  return m68k_lock_test_and_set(dest, exchange_value);
+#else
+  return __sync_lock_test_and_set (dest, exchange_value);
+#endif // M68K
+#endif // ARM
+}
+
+inline void* Atomic::xchg_ptr(void* exchange_value, volatile void* dest) {
+  return (void *) xchg_ptr((intptr_t) exchange_value,
+                           (volatile intptr_t*) dest);
+}
+
+inline jint Atomic::cmpxchg(jint exchange_value,
+                            volatile jint* dest,
+                            jint compare_value) {
+#ifdef ARM
+  return arm_compare_and_swap(dest, compare_value, exchange_value);
+#else
+#ifdef M68K
+  return m68k_compare_and_swap(dest, compare_value, exchange_value);
+#else
+  return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
+#endif // M68K
+#endif // ARM
+}
+
+inline jlong Atomic::cmpxchg(jlong exchange_value,
+                             volatile jlong* dest,
+                             jlong compare_value) {
+
+  return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
+}
+
+inline intptr_t Atomic::cmpxchg_ptr(intptr_t exchange_value,
+                                    volatile intptr_t* dest,
+                                    intptr_t compare_value) {
+#ifdef ARM
+  return arm_compare_and_swap(dest, compare_value, exchange_value);
+#else
+#ifdef M68K
+  return m68k_compare_and_swap(dest, compare_value, exchange_value);
+#else
+  return __sync_val_compare_and_swap(dest, compare_value, exchange_value);
+#endif // M68K
+#endif // ARM
+}
+
+inline void* Atomic::cmpxchg_ptr(void* exchange_value,
+                                 volatile void* dest,
+                                 void* compare_value) {
+
+  return (void *) cmpxchg_ptr((intptr_t) exchange_value,
+                              (volatile intptr_t*) dest,
+                              (intptr_t) compare_value);
+}