Add support for forced ethernet speed setting.
Currently testpmd tries to configure the Ethernet port in autoneg mode.
It is not possible to set the Ethernet port to a specific speed while
starting testpmd. In some cases capability to configure a forced speed
for the Ethernet port during initialization may be necessary. This patch
tries to add this support.

The patch assumes full duplex setting and does not attempt to change that.
So speeds like 10M, 100M are not configurable using this method.

The command line to configure a forced speed of 10G:
dpdk-testpmd -c 0xff  -- -i  --eth-link-speed  10000

The command line to configure a forced speed of 50G:
dpdk-testpmd -c 0xff  -- -i  --eth-link-speed  50000

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
---
 app/test-pmd/parameters.c             | 42 +++++++++++++++++++++++++++
 app/test-pmd/testpmd.c                |  4 +++
 app/test-pmd/testpmd.h                |  1 +
 doc/guides/testpmd_app_ug/run_app.rst | 11 +++++++
 4 files changed, 58 insertions(+)

diff --git a/app/test-pmd/parameters.c b/app/test-pmd/parameters.c
index c8acd5d1b7..e10f7d38fb 100644
--- a/app/test-pmd/parameters.c
+++ b/app/test-pmd/parameters.c
@@ -224,6 +224,7 @@ usage(char* progname)
 	printf("  --hairpin-mode=0xXX: bitmask set the hairpin port mode.\n "
 	       "    0x10 - explicit Tx rule, 0x02 - hairpin ports paired\n"
 	       "    0x01 - hairpin ports loop, 0x00 - hairpin port self\n");
+	printf("  --eth-link-speed: forced link speed.\n");
 }
 
 #ifdef RTE_LIB_CMDLINE
@@ -485,6 +486,41 @@ parse_event_printing_config(const char *optarg, int enable)
 	return 0;
 }
 
+static int
+parse_link_speed(int n)
+{
+	uint32_t speed;
+
+	switch (n) {
+	case 1000:
+		speed = ETH_LINK_SPEED_1G;
+		break;
+	case 10000:
+		speed = ETH_LINK_SPEED_10G;
+		break;
+	case 25000:
+		speed = ETH_LINK_SPEED_25G;
+		break;
+	case 40000:
+		speed = ETH_LINK_SPEED_40G;
+		break;
+	case 50000:
+		speed = ETH_LINK_SPEED_50G;
+		break;
+	case 100000:
+		speed = ETH_LINK_SPEED_100G;
+		break;
+	case 200000:
+		speed = ETH_LINK_SPEED_200G;
+		break;
+	default:
+		speed = ETH_LINK_SPEED_AUTONEG;
+		break;
+	}
+
+	return speed;
+}
+
 void
 launch_args_parse(int argc, char** argv)
 {
@@ -605,6 +641,7 @@ launch_args_parse(int argc, char** argv)
 		{ "rx-mq-mode",                 1, 0, 0 },
 		{ "record-core-cycles",         0, 0, 0 },
 		{ "record-burst-stats",         0, 0, 0 },
+		{ "eth-link-speed",		1, 0, 0 },
 		{ 0, 0, 0, 0 },
 	};
 
@@ -1366,6 +1403,11 @@ launch_args_parse(int argc, char** argv)
 				record_core_cycles = 1;
 			if (!strcmp(lgopts[opt_idx].name, "record-burst-stats"))
 				record_burst_stats = 1;
+			if (!strcmp(lgopts[opt_idx].name, "eth-link-speed")) {
+				n = atoi(optarg);
+				if (n >= 0 && parse_link_speed(n) >= 0)
+					eth_link_speed = parse_link_speed(n);
+			}
 			break;
 		case 'h':
 			usage(argv[0]);
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index caa711d6f3..9434e335a0 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -535,6 +535,8 @@ uint16_t gso_max_segment_size = RTE_ETHER_MAX_LEN - RTE_ETHER_CRC_LEN;
 /* Holds the registered mbuf dynamic flags names. */
 char dynf_names[64][RTE_MBUF_DYN_NAMESIZE];
 
+uint32_t eth_link_speed;
+
 /*
  * Helper function to check if socket is already discovered.
  * If yes, return positive value. If not, return zero.
@@ -1484,6 +1486,8 @@ init_config(void)
 			port->tx_conf[k].offloads =
 				port->dev_conf.txmode.offloads;
 
+		port->dev_conf.link_speeds = eth_link_speed;
+
 		/* set flag to initialize port/queue */
 		port->need_reconfig = 1;
 		port->need_reconfig_queues = 1;
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index 60ddeb8f13..a3cd4a0e16 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -351,6 +351,7 @@ extern bool setup_on_probe_event; /**< disabled by port setup-on iterator */
 extern uint8_t hot_plug; /**< enable by "--hot-plug" parameter */
 extern int do_mlockall; /**< set by "--mlockall" or "--no-mlockall" parameter */
 extern uint8_t clear_ptypes; /**< disabled by set ptype cmd */
+extern uint32_t eth_link_speed;
 
 #ifdef RTE_LIBRTE_IXGBE_BYPASS
 extern uint32_t bypass_timeout; /**< Store the NIC bypass watchdog timeout */
diff --git a/doc/guides/testpmd_app_ug/run_app.rst b/doc/guides/testpmd_app_ug/run_app.rst
index 6745072329..a856f52736 100644
--- a/doc/guides/testpmd_app_ug/run_app.rst
+++ b/doc/guides/testpmd_app_ug/run_app.rst
@@ -536,3 +536,14 @@ The command line options are:
     bit 1 - two hairpin ports paired
     bit 0 - two hairpin ports loop
     The default value is 0. Hairpin will use single port mode and implicit Tx flow mode.
+
+*   ``--eth-link-speed``
+
+    Set a forced link speed to the ethernet port.
+    1000 - 1Gbps
+    10000 - 10Gbps
+    25000 - 25Gbps
+    40000 - 40Gbps
+    50000 - 50Gbps
+    100000 - 100Gbps
+    200000 - 200Gbps
-- 
2.21.1 (Apple Git-122.3)