[dpdk-dev] [RFC PATCH 4/4] example app showing pktdevs used in a chain

[Bruce Richardson <bruce.richardson@intel.com>]

This is a trivial example showing code which is using ethdevs and rings
in a neutral manner, with the same piece of pipeline code passing mbufs
along a chain without ever having to query its source or destination
type.
---
 examples/pktdev/Makefile   |  57 ++++++++++++
 examples/pktdev/basicfwd.c | 222 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 279 insertions(+)
 create mode 100644 examples/pktdev/Makefile
 create mode 100644 examples/pktdev/basicfwd.c

diff --git a/examples/pktdev/Makefile b/examples/pktdev/Makefile
new file mode 100644
index 0000000..4a5d99f
--- /dev/null
+++ b/examples/pktdev/Makefile
@@ -0,0 +1,57 @@
+#   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.
+
+ifeq ($(RTE_SDK),)
+$(error "Please define RTE_SDK environment variable")
+endif
+
+# Default target, can be overridden by command line or environment
+RTE_TARGET ?= x86_64-native-linuxapp-gcc
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+# binary name
+APP = basicfwd
+
+# all source are stored in SRCS-y
+SRCS-y := basicfwd.c
+
+CFLAGS += $(WERROR_FLAGS)
+
+# workaround for a gcc bug with noreturn attribute
+# http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12603
+ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
+CFLAGS_main.o += -Wno-return-type
+endif
+
+EXTRA_CFLAGS += -O3 -g -Wfatal-errors
+
+include $(RTE_SDK)/mk/rte.extapp.mk
diff --git a/examples/pktdev/basicfwd.c b/examples/pktdev/basicfwd.c
new file mode 100644
index 0000000..e06bcfe
--- /dev/null
+++ b/examples/pktdev/basicfwd.c
@@ -0,0 +1,222 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2015 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.
+ */
+
+#include <stdint.h>
+#include <inttypes.h>
+#include <rte_eal.h>
+#include <rte_ethdev.h>
+#include <rte_cycles.h>
+#include <rte_lcore.h>
+#include <rte_mbuf.h>
+
+#define RX_RING_SIZE 128
+#define TX_RING_SIZE 512
+
+#define NUM_MBUFS 8191
+#define MBUF_SIZE (1600 + sizeof(struct rte_mbuf) + RTE_PKTMBUF_HEADROOM)
+#define MBUF_CACHE_SIZE 250
+#define BURST_SIZE 32
+
+static const struct rte_eth_conf port_conf_default = {
+	.rxmode = { .max_rx_pkt_len = ETHER_MAX_LEN }
+};
+
+/* basicfwd.c: Basic DPDK skeleton forwarding example. */
+
+/*
+ * Initializes a given port using global settings and with the RX buffers
+ * coming from the mbuf_pool passed as a parameter.
+ */
+static inline int
+port_init(uint8_t port, struct rte_mempool *mbuf_pool)
+{
+	struct rte_eth_conf port_conf = port_conf_default;
+	const uint16_t rx_rings = 1, tx_rings = 1;
+	int retval;
+	uint16_t q;
+
+	if (port >= rte_eth_dev_count())
+		return -1;
+
+	/* Configure the Ethernet device. */
+	retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
+	if (retval != 0)
+		return retval;
+
+	/* Allocate and set up 1 RX queue per Ethernet port. */
+	for (q = 0; q < rx_rings; q++) {
+		retval = rte_eth_rx_queue_setup(port, q, RX_RING_SIZE,
+				rte_eth_dev_socket_id(port), NULL, mbuf_pool);
+		if (retval < 0)
+			return retval;
+	}
+
+	/* Allocate and set up 1 TX queue per Ethernet port. */
+	for (q = 0; q < tx_rings; q++) {
+		retval = rte_eth_tx_queue_setup(port, q, TX_RING_SIZE,
+				rte_eth_dev_socket_id(port), NULL);
+		if (retval < 0)
+			return retval;
+	}
+
+	/* Start the Ethernet port. */
+	retval = rte_eth_dev_start(port);
+	if (retval < 0)
+		return retval;
+
+	/* Display the port MAC address. */
+	struct ether_addr addr;
+	rte_eth_macaddr_get(port, &addr);
+	printf("Port %u MAC: %02" PRIx8 " %02" PRIx8 " %02" PRIx8
+			   " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 "\n",
+			(unsigned)port,
+			addr.addr_bytes[0], addr.addr_bytes[1],
+			addr.addr_bytes[2], addr.addr_bytes[3],
+			addr.addr_bytes[4], addr.addr_bytes[5]);
+
+	/* Enable RX in promiscuous mode for the Ethernet device. */
+	rte_eth_promiscuous_enable(port);
+
+	return 0;
+}
+
+struct pipeline_params {
+	struct rte_pkt_dev *src;
+	struct rte_pkt_dev *dst;
+};
+
+/*
+ * The lcore main. This is the main thread that does the work, reading from
+ * an input port and writing to an output port.
+ */
+static __attribute__((noreturn)) void
+do_work(const struct pipeline_params *p)
+{
+	printf("\nCore %u forwarding packets. %s -> %s\n",
+			rte_lcore_id(),
+			p->src->data->name,
+			p->dst->data->name);
+
+	/* Run until the application is quit or killed. */
+	for (;;) {
+		/*
+		 * Receive packets on a src device and forward them on out
+		 * the dst device.
+		 */
+		/* Get burst of RX packets, from first port of pair. */
+		struct rte_mbuf *bufs[BURST_SIZE];
+		const uint16_t nb_rx = rte_pkt_rx_burst(p->src, 0,
+				bufs, BURST_SIZE);
+
+		if (unlikely(nb_rx == 0))
+			continue;
+
+		/* Send burst of TX packets, to second port of pair. */
+		const uint16_t nb_tx = rte_pkt_tx_burst(p->dst, 0,
+				bufs, nb_rx);
+
+		/* Free any unsent packets. */
+		if (unlikely(nb_tx < nb_rx)) {
+			uint16_t buf;
+			for (buf = nb_tx; buf < nb_rx; buf++)
+				rte_pktmbuf_free(bufs[buf]);
+		}
+	}
+}
+
+/*
+ * The main function, which does initialization and calls the per-lcore
+ * functions.
+ */
+int
+main(int argc, char *argv[])
+{
+	struct pipeline_params p[RTE_MAX_LCORE];
+	struct rte_mempool *mbuf_pool;
+	unsigned nb_ports, lcore_id;
+	uint8_t portid;
+
+	/* Initialize the Environment Abstraction Layer (EAL). */
+	int ret = rte_eal_init(argc, argv);
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
+
+	argc -= ret;
+	argv += ret;
+
+	/* Check that there is an even number of ports to send/receive on. */
+	nb_ports = rte_eth_dev_count();
+	if (nb_ports < 2 || (nb_ports & 1))
+		rte_exit(EXIT_FAILURE, "Error: number of ports must be even\n");
+
+	/* Creates a new mempool in memory to hold the mbufs. */
+	mbuf_pool = rte_mempool_create("MBUF_POOL",
+				       NUM_MBUFS * nb_ports,
+				       MBUF_SIZE,
+				       MBUF_CACHE_SIZE,
+				       sizeof(struct rte_pktmbuf_pool_private),
+				       rte_pktmbuf_pool_init, NULL,
+				       rte_pktmbuf_init,      NULL,
+				       rte_socket_id(),
+				       0);
+
+	if (mbuf_pool == NULL)
+		rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");
+
+	/* Initialize all ports. */
+	for (portid = 0; portid < nb_ports; portid++)
+		if (port_init(portid, mbuf_pool) != 0)
+			rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu8 "\n",
+					portid);
+
+	struct rte_pkt_dev *in = rte_eth_get_dev(0);
+	RTE_LCORE_FOREACH_SLAVE(lcore_id){
+		char name[RTE_RING_NAMESIZE];
+		snprintf(name, sizeof(name), "RING_from_%u", lcore_id);
+		struct rte_pkt_dev *out = rte_ring_get_dev(
+				rte_ring_create(name, 4096, rte_socket_id(), 0));
+
+		p[lcore_id].src = in;
+		p[lcore_id].dst = out;
+		rte_eal_remote_launch((lcore_function_t *)do_work,
+				&p[lcore_id], lcore_id);
+		in = out; // next pipeline stage reads from my output.
+	}
+	//now finish pipeline on master lcore
+	lcore_id = rte_lcore_id();
+	p[lcore_id].src = in;
+	p[lcore_id].dst = rte_eth_get_dev(1);
+	do_work(&p[lcore_id]);
+
+	return 0;
+}
-- 
2.1.0