--- /dev/null
+/* -------------------------------------------------------------- */
+/* (C)Copyright 2001,2007, */
+/* International Business Machines Corporation, */
+/* Sony Computer Entertainment, Incorporated, */
+/* Toshiba Corporation, */
+/* */
+/* All Rights Reserved. */
+/* */
+/* Redistribution and use in source and binary forms, with or */
+/* without modification, are permitted provided that the */
+/* following conditions are met: */
+/* */
+/* - Redistributions of source code must retain the above copyright*/
+/* notice, this list of conditions and the following disclaimer. */
+/* */
+/* - Redistributions in binary form must reproduce the above */
+/* copyright notice, this list of conditions and the following */
+/* disclaimer in the documentation and/or other materials */
+/* provided with the distribution. */
+/* */
+/* - Neither the name of IBM Corporation nor the names of its */
+/* contributors may be used to endorse or promote products */
+/* derived from this software without specific prior written */
+/* permission. */
+/* */
+/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND */
+/* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, */
+/* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */
+/* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE */
+/* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR */
+/* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */
+/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT */
+/* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; */
+/* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) */
+/* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */
+/* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR */
+/* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */
+/* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
+/* -------------------------------------------------------------- */
+/* PROLOG END TAG zYx */
+#ifndef _PPU_ATOMIC_DEC_IF_POSITIVE_H_
+#define _PPU_ATOMIC_DEC_IF_POSITIVE_H_
+
+#include <ppu_intrinsics.h>
+#include "sync_utils.h"
+#include "atomic.h"
+
+/*
+ * atomic_dec_if_positive - atomically decrement if counter is positive.
+ *
+ * v: handle to effective address of counter.
+ *
+ * Atomically decrement a counter if its value is positive.
+ * The only restriction is that v must be word aligned.
+ *
+ *
+ * Returns the old value of the counter, minus 1.
+ */
+static __inline int _atomic_dec_if_positive(atomic_ea_t v)
+{
+ int ret;
+ int tmp;
+ void *p;
+
+ SYNC_ULL_TO_PTR(v, p);
+
+ do {
+ tmp = (int)__lwarx(p);
+ ret = tmp - 1;
+ tmp = (tmp > 0) ? ret : tmp;
+ } while (__stwcx(p, (unsigned)tmp) == 0);
+
+ return ret;
+}
+
+#endif /* _PPU_ATOMIC_DEC_IF_POSITIVE_H_ */