eal: introduce architecture specific pause function

Each architecture may have different instructions for optimized
and power consumption aware rte_pause() implementation.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

diff --git a/doc/api/doxy-api-index.md b/doc/api/doxy-api-index.md
index f5f1f19..3b83288 100644 (file)
--- a/doc/api/doxy-api-index.md
+++ b/doc/api/doxy-api-index.md
@@ -77,6 +77,7 @@ There are many libraries, so their headers may be grouped by topics:
   [SIMD]               (@ref rte_vect.h),
   [byte order]         (@ref rte_byteorder.h),
   [CPU flags]          (@ref rte_cpuflags.h),
+  [CPU pause]          (@ref rte_pause.h),
   [I/O access]         (@ref rte_io.h)
 
 - **CPU multicore**:

diff --git a/lib/librte_eal/common/Makefile b/lib/librte_eal/common/Makefile
index a5bd108..f2fe052 100644 (file)
--- a/lib/librte_eal/common/Makefile
+++ b/lib/librte_eal/common/Makefile
@@ -44,7 +44,7 @@ INC += rte_malloc.h rte_keepalive.h rte_time.h
 
 GENERIC_INC := rte_atomic.h rte_byteorder.h rte_cycles.h rte_prefetch.h
 GENERIC_INC += rte_spinlock.h rte_memcpy.h rte_cpuflags.h rte_rwlock.h
-GENERIC_INC += rte_vect.h rte_io.h
+GENERIC_INC += rte_vect.h rte_pause.h rte_io.h
 
 # defined in mk/arch/$(RTE_ARCH)/rte.vars.mk
 ARCH_DIR ?= $(RTE_ARCH)

diff --git a/lib/librte_eal/common/include/generic/rte_pause.h b/lib/librte_eal/common/include/generic/rte_pause.h
new file mode 100644 (file)
index 0000000..9625e58
--- /dev/null
+++ b/lib/librte_eal/common/include/generic/rte_pause.h
@@ -0,0 +1,52 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2017 Cavium. All rights reserved.
+ *   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 Cavium 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.
+ */
+
+#ifndef _RTE_PAUSE_H_
+#define _RTE_PAUSE_H_
+
+/**
+ * @file
+ *
+ * CPU pause operation.
+ *
+ */
+
+/**
+ * Pause CPU execution for a short while
+ *
+ * This call is intended for tight loops which poll a shared resource or wait
+ * for an event. A short pause within the loop may reduce the power consumption.
+ */
+static inline void rte_pause(void);
+
+#endif /* _RTE_PAUSE_H_ */