--- /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 _SPU_ATOMIC_DEC_IF_POSITIVE_H_
+#define _SPU_ATOMIC_DEC_IF_POSITIVE_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)
+{
+ DECL_ATOMIC_VARS();
+ s32 status;
+
+ ea64.ull = ALIGN128_EA(v);
+ offset = OFFSET128_EA_U32(v);
+ do {
+ MFC_DMA(buf, ea64, size, tagid, MFC_GETLLAR_CMD);
+ spu_readch(MFC_RdAtomicStat);
+
+ ret_val = buf[offset] - 1;
+ if (likely(ret_val >= 0)) {
+ buf[offset] = ret_val;
+ MFC_DMA(buf, ea64, size, tagid, MFC_PUTLLC_CMD);
+ status = spu_readch(MFC_RdAtomicStat);
+ } else {
+ MFC_DMA(buf, ea64, size, tagid, MFC_PUTLLC_CMD);
+ spu_readch(MFC_RdAtomicStat);
+ status = 0;
+ break;
+ }
+ } while (status != 0);
+
+ return ret_val;
+}
+
+
+
+#endif /* _SPU_ATOMIC_DEC_IF_POSITIVE_H_ */