[dpdk-dev] [PATCH v2 2/2] doc: User-space ethtool sample application

[Remy Horton]

Signed-off-by: Remy Horton <remy.horton at intel.com>
---
 doc/guides/sample_app_ug/ethtool.rst | 265 +++++++++++++++++++++++++++++++++++
 doc/guides/sample_app_ug/index.rst   |   1 +
 2 files changed, 266 insertions(+)
 create mode 100644 doc/guides/sample_app_ug/ethtool.rst

diff --git a/doc/guides/sample_app_ug/ethtool.rst b/doc/guides/sample_app_ug/ethtool.rst
new file mode 100644
index 0000000..6d71908
--- /dev/null
+++ b/doc/guides/sample_app_ug/ethtool.rst
@@ -0,0 +1,265 @@
+
+..  BSD LICENSE
+    Copyright(c) 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.
+
+EthTool Sample Application
+==========================
+
+The Ethtool sample application shows an implementation of an
+EthTool-like API and provides a console environment that allows
+its use to query and change Ethernet card parameters. The sample
+is based upon a simple L2 frame reflector.
+
+
+Compiling the Application
+-------------------------
+
+To compile the application:
+
+#.  Go to the sample application directory:
+
+    .. code-block:: console
+
+        export RTE_SDK=/path/to/rte_sdk cd ${RTE_SD}/examples/ethtool
+
+#.  Set the target (a default target is used if not specified). For example:
+
+    .. code-block:: console
+
+        export RTE_TARGET=x86_64-native-linuxapp-gcc
+
+    See the *DPDK Getting Started Guide* for possible RTE_TARGET values.
+
+#.  Build the application:
+
+    .. code-block:: console
+
+        make
+
+Running the Application
+-----------------------
+
+The application requires an available core for each port, plus one.
+The only available options are the standard ones for the EAL:
+
+.. code-block:: console
+
+    ./build/ethtool [EAL options]
+
+Refer to the *DPDK Getting Started Guide* for general information on
+running applications and the Environment Abstraction Layer (EAL)
+options.
+
+Using the application
+---------------------
+
+The application is console-driven using the cmdline DPDK interface:
+
+.. code-block:: console
+
+        EthApp>
+
+From this interface the available commands and descriptions of what
+they do as as follows:
+
+drvinfo
+        Print driver info
+eeprom
+        Dump EEPROM to file
+link
+        Print port link states
+macaddr
+        Gets/sets MAC address
+mtu
+        Set NIC MTU
+open
+        Open port
+pause
+        Get/set port pause state
+portstats
+        Print port statistics
+regs
+        Dump port register(s) to file
+ringparam
+        Get/set ring parameters
+rxmode
+        Toggle port Rx mode
+stop
+        Stop port
+validate
+        Check that given MAC address is valid unicast address
+vlan
+        Add/remove VLAN id
+quit
+        Exit program
+
+
+Explaination
+------------
+
+The following sections describe the most important parts of the code.
+
+
+Base program
+~~~~~~~~~~~~
+
+The top-level, after some port initialisation routines, runs the following:
+
+.. code-block:: c
+
+	for (idx_port = 0; idx_port < cnt_ports; idx_port++) {
+		ptr_port = &app_cfg.ports[idx_port];
+		rte_eal_remote_launch(slave_main, ptr_port, idx_port + 1);
+	}
+
+	ethapp_main();
+
+Each slave core, or a subset of these cores if there are more cores then
+NIC ports, runs the `slave core process`_ described below. The master core
+then runs the `EthTool App`_ itself.
+
+
+Slave core process
+~~~~~~~~~~~~~~~~~~
+
+Each slave core is assigned one of the available ports, and runs
+the following code that implements a simple MAC frame refector:
+
+.. code-block:: c
+
+	while (!ptr_port->exit_now) {
+		rte_spinlock_lock(&ptr_port->lock);
+		if (ptr_port->port_active == 0 ) {
+			rte_spinlock_unlock(&ptr_port->lock);
+			continue;
+		}
+
+		/* Incoming frames */
+		cnt_backlog_frames = ptr_txq->cnt_frames;
+		cnt_recv_frames = rte_eth_rx_burst(
+			ptr_port->idx_port, 0,
+			&buf_recv_frames[ptr_txq->cnt_frames],
+			MAX_BURST_LENGTH - cnt_backlog_frames
+			);
+		if (cnt_recv_frames > 0) {
+			for (idx_frame = 0;
+					idx_frame < cnt_recv_frames;
+					idx_frame++) {
+				ptr_frame = buf_recv_frames[
+					idx_frame + cnt_backlog_frames];
+				process_frame(ptr_port, ptr_frame);
+			}
+		}
+
+		/* Outgoing frames */
+		if (ptr_txq->cnt_frames > 0) {
+			cnt_sent = rte_eth_tx_burst(
+				ptr_port->idx_port, 0,
+				ptr_txq->ptr_frames,
+				ptr_txq->cnt_frames
+				);
+			/* Shuffle up unsent frame pointers */
+			for (idx_frame = cnt_sent;
+					idx_frame < ptr_txq->cnt_frames;
+					idx_frame++)
+				ptr_txq->ptr_frames[idx_frame - cnt_sent] =
+					ptr_txq->ptr_frames[idx_frame];
+			ptr_txq->cnt_frames -= cnt_sent;
+		}
+		rte_spinlock_unlock(&ptr_port->lock);
+
+	} /* end for(;;) */
+
+There is a check to make sure the port is in an active state. A burst
+of frames is read and each frame within this burst is processed as
+described below. Outgoing frames are then dispatched as a single burst,
+with unsent frames being shuffled to the front of the outgoing queue if
+not all of the frames could be sent.
+
+The processing of individial frames consists of setting the destination
+address to be the source address, setting the source address to be the
+MAC address of the port being handled, and then queueing the frame for
+transmission:
+
+.. code-block:: c
+
+	ptr_mac_hdr = rte_pktmbuf_mtod(ptr_frame, struct ether_hdr *);
+	ether_addr_copy(&ptr_mac_hdr->s_addr, &ptr_mac_hdr->d_addr);
+	rte_eth_macaddr_get(ptr_port->idx_port, &ptr_mac_hdr->s_addr);
+	ptr_port->tx_queue.ptr_frames[ptr_port->tx_queue.cnt_frames++] =
+		ptr_frame;
+
+
+EthTool App
+~~~~~~~~~~~
+
+The ``foreground`` part of the EthTool sample is a console-based
+interface that accepts commands as described in `using the
+application`_.
+
+.. code-block:: c
+
+	ctx_cmdline = cmdline_stdin_new(list_prompt_commands, "EthApp> ");
+	cmdline_interact(ctx_cmdline);
+	cmdline_stdin_exit(ctx_cmdline);
+
+
+Individual call-back functions handle the detail associated with each
+command, which make use of the functions defined in the `EthTool interface`_
+to the DPDK functions.
+
+
+EthTool interface
+~~~~~~~~~~~~~~~~~
+
+The EthTool interface is built as a separate library, and implements
+the following functions:
+
+- rte_ethtool_get_drvinfo
+- rte_ethtool_get_regs_len
+- rte_ethtool_get_regs
+- rte_ethtool_get_link
+- rte_ethtool_get_eeprom_len
+- rte_ethtool_get_eeprom
+- rte_ethtool_set_eeprom
+- rte_ethtool_get_pauseparam
+- rte_ethtool_set_pauseparam
+- rte_ethtool_net_open
+- rte_ethtool_net_stop
+- rte_ethtool_net_get_mac_addr
+- rte_ethtool_net_set_mac_addr
+- rte_ethtool_net_validate_addr
+- rte_ethtool_net_change_mtu
+- rte_ethtool_net_get_stats64
+- rte_ethtool_net_vlan_rx_add_vid
+- rte_ethtool_net_vlan_rx_kill_vid
+- rte_ethtool_net_set_rx_mode
+- rte_ethtool_get_ringparam
+- rte_ethtool_set_ringparam
diff --git a/doc/guides/sample_app_ug/index.rst b/doc/guides/sample_app_ug/index.rst
index 9beedd9..086d3f2 100644
--- a/doc/guides/sample_app_ug/index.rst
+++ b/doc/guides/sample_app_ug/index.rst
@@ -41,6 +41,7 @@ Sample Applications User Guide
 
     intro
     cmd_line
+    ethtool
     exception_path
     hello_world
     skeleton
-- 
1.9.3