[dpdk-dev] [PATCH] Add toeplitz hash algorithm

Vladimir Medvedkin medvedkinv at gmail.com
Wed Apr 8 21:06:13 CEST 2015


Software implementation of the Toeplitz hash function used by RSS.
Can be used either for packet distribution on single queue NIC
or for simulating of RSS computation on specific NIC (for example
after GRE header decapsulating).

Signed-off-by: Vladimir Medvedkin <medvedkinv at gmail.com>
---
 lib/librte_hash/Makefile    |   1 +
 lib/librte_hash/rte_thash.h | 179 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 180 insertions(+)
 create mode 100644 lib/librte_hash/rte_thash.h

diff --git a/lib/librte_hash/Makefile b/lib/librte_hash/Makefile
index 3696cb1..083a9e5 100644
--- a/lib/librte_hash/Makefile
+++ b/lib/librte_hash/Makefile
@@ -50,6 +50,7 @@ SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include := rte_hash.h
 SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_hash_crc.h
 SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_jhash.h
 SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_fbk_hash.h
+SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_thash.h
 
 # this lib needs eal
 DEPDIRS-$(CONFIG_RTE_LIBRTE_HASH) += lib/librte_eal lib/librte_malloc
diff --git a/lib/librte_hash/rte_thash.h b/lib/librte_hash/rte_thash.h
new file mode 100644
index 0000000..1acfa3a
--- /dev/null
+++ b/lib/librte_hash/rte_thash.h
@@ -0,0 +1,179 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. 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 Intel 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.
+ */
+
+#ifndef _RTE_THASH_H
+#define _RTE_THASH_H
+
+/**
+ * @file
+ *
+ * toeplitz hash functions.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Software implementation of the Toeplitz hash function used by RSS.
+ * Can be used either for packet distribution on single queue NIC
+ * or for simulating of RSS computation on specific NIC (for example
+ * after GRE header decapsulating)
+ */
+
+#include <stdint.h>
+#include <rte_byteorder.h>
+
+enum rte_thash_flag {
+	RTE_THASH_L3 = 0,	//calculate hash tacking into account only l3 header
+	RTE_THASH_L4		//calculate hash tacking into account l4 + l4 headers
+};
+
+/**
+ * Prepare special converted key to use with rte_softrss_be()
+ * @param orig
+ *   pointer to original RSS key
+ * @param targ
+ *   pointer to target RSS key
+ */
+
+static inline void
+rte_convert_rss_key(uint32_t *orig, uint32_t *targ)
+{
+	int i;
+	for (i = 0; i < 10; i++) {
+		targ[i] = rte_be_to_cpu_32(orig[i]);
+	}
+}
+
+/**
+ * Generic implementation. Can be used with original rss_key
+ * All ip's and ports have to be CPU byte order.
+ * @param sip
+ *   Source ip address.
+ * @param dip
+ *   Destination ip address.
+ * @param sp
+ *   Source TCP|UDP port.
+ * @param dp
+ *   Destination TCP|UDP port.
+ * @param flag
+ *   RTE_THASH_L3:	calculate hash tacking into account only sip and dip
+ *   RTE_THASH_L4:	calculate hash tacking into account sip, dip, sp and dp
+ * @param *rss_key
+ *   Pointer to 40-byte RSS hash key.
+ * @return
+ *   Calculated hash value.
+ */
+
+static inline uint32_t
+rte_softrss(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp, enum rte_thash_flag flag, uint32_t *rss_key)
+{
+	uint32_t ret = 0;
+	int i;
+	for (i = 0; i < 32; i++) {
+		if (sip & (1 << (31 - i))) {
+			ret ^= (rte_cpu_to_be_32(*rss_key) << i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
+		}
+	}
+	rss_key++;
+	for (i = 0; i < 32; i++) {
+		if (dip & (1 << (31 - i))) {
+			ret ^= (rte_cpu_to_be_32(*rss_key) << i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
+		}
+	}
+        if (flag == RTE_THASH_L4) {
+		rss_key++;
+		for (i = 0; i < 32; i++) {
+			if (((sp<<16)|dp) & (1 << (31 - i))) {
+				ret ^= (rte_cpu_to_be_32(*rss_key) << i)|(uint32_t)((uint64_t)(rte_cpu_to_be_32(*(rss_key + 1))) >> (32 - i));
+			}
+		}
+	}
+	return ret;
+}
+
+/**
+ * Optimized implementation.
+ * If you want the calculated hash value matches NIC RSS value
+ * you have to use special converted key.
+ * All ip's and ports have to be CPU byte order.
+ * @param sip
+ *   Source ip address.
+ * @param dip
+ *   Destination ip address.
+ * @param sp
+ *   Source TCP|UDP port.
+ * @param dp
+ *   Destination TCP|UDP port.
+ * @param flag
+ *   RTE_THASH_L3:	calculate hash tacking into account only sip and dip
+ *   RTE_THASH_L4:	calculate hash tacking into account sip, dip, sp and dp
+ * @param *rss_key
+ *   Pointer to 40-byte RSS hash key.
+ * @return
+ *   Calculated hash value.
+ */
+
+static inline uint32_t
+rte_softrss_be(uint32_t sip, uint32_t dip, uint16_t sp, uint16_t dp, enum rte_thash_flag flag, uint32_t *rss_key)
+{
+	uint32_t ret = 0;
+	int i;
+	for (i = 0; i < 32; i++) {
+		if (sip & (1 << (31 - i))) {
+			ret ^= (*rss_key << i)|(uint32_t)((uint64_t)*(rss_key + 1) >> (32 - i));
+		}
+	}
+	rss_key++;
+	for (i = 0; i < 32; i++) {
+		if (dip & (1 << (31 - i))) {
+			ret ^= (*rss_key << i)|(uint32_t)((uint64_t)*(rss_key + 1) >> (32 - i));
+		}
+	}
+        if (flag == RTE_THASH_L4) {
+		rss_key++;
+		for (i = 0; i < 32; i++) {
+			if (((sp<<16)|dp) & (1 << (31 - i))) {
+				ret ^= (*rss_key << i)|(uint32_t)((uint64_t)*(rss_key + 1) >> (32 - i));
+			}
+		}
+	}
+	return ret;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_THASH_H */
-- 
1.8.3.2



More information about the dev mailing list