--- /dev/null
+.. 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.
+
+**Part 1: Architecture Overview**
+
+Overview
+========
+
+This section gives a global overview of the architecture of Data Plane Development Kit (DPDK).
+
+The main goal of the DPDK is to provide a simple,
+complete framework for fast packet processing in data plane applications.
+Users may use the code to understand some of the techniques employed,
+to build upon for prototyping or to add their own protocol stacks.
+Alternative ecosystem options that use the DPDK are available.
+
+The framework creates a set of libraries for specific environments
+through the creation of an Environment Abstraction Layer (EAL),
+which may be specific to a mode of the Intel® architecture (32-bit or 64-bit),
+Linux* user space compilers or a specific platform.
+These environments are created through the use of make files and configuration files.
+Once the EAL library is created, the user may link with the library to create their own applications.
+Other libraries, outside of EAL, including the Hash,
+Longest Prefix Match (LPM) and rings libraries are also provided.
+Sample applications are provided to help show the user how to use various features of the DPDK.
+
+The DPDK implements a run to completion model for packet processing,
+where all resources must be allocated prior to calling Data Plane applications,
+running as execution units on logical processing cores.
+The model does not support a scheduler and all devices are accessed by polling.
+The primary reason for not using interrupts is the performance overhead imposed by interrupt processing.
+
+In addition to the run-to-completion model,
+a pipeline model may also be used by passing packets or messages between cores via the rings.
+This allows work to be performed in stages and may allow more efficient use of code on cores.
+
+Development Environment
+-----------------------
+
+The DPDK project installation requires Linux and the associated toolchain,
+such as one or more compilers, assembler, make utility,
+editor and various libraries to create the DPDK components and libraries.
+
+Once these libraries are created for the specific environment and architecture,
+they may then be used to create the user's data plane application.
+
+When creating applications for the Linux user space, the glibc library is used.
+For DPDK applications, two environmental variables (RTE_SDK and RTE_TARGET)
+must be configured before compiling the applications.
+The following are examples of how the variables can be set:
+
+.. code-block:: console
+
+ export RTE_SDK=/home/user/DPDK
+ export RTE_TARGET=x86_64-native-linuxapp-gcc
+
+See the *DPDK Getting Started Guide* for information on setting up the development environment.
+
+Environment Abstraction Layer
+-----------------------------
+
+The Environment Abstraction Layer (EAL) provides a generic interface
+that hides the environment specifics from the applications and libraries.
+The services provided by the EAL are:
+
+* DPDK loading and launching
+
+* Support for multi-process and multi-thread execution types
+
+* Core affinity/assignment procedures
+
+* System memory allocation/de-allocation
+
+* Atomic/lock operations
+
+* Time reference
+
+* PCI bus access
+
+* Trace and debug functions
+
+* CPU feature identification
+
+* Interrupt handling
+
+* Alarm operations
+
+* Memory management (malloc)
+
+The EAL is fully described in :ref:`Environment Abstraction Layer <Environment_Abstraction_Layer>`.
+
+Core Components
+---------------
+
+The *core components* are a set of libraries that provide all the elements needed
+for high-performance packet processing applications.
+
+.. _figure_architecture-overview:
+
+.. figure:: img/architecture-overview.*
+
+ Core Components Architecture
+
+
+Ring Manager (librte_ring)
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ring structure provides a lockless multi-producer, multi-consumer FIFO API in a finite size table.
+It has some advantages over lockless queues; easier to implement, adapted to bulk operations and faster.
+A ring is used by the :ref:`Memory Pool Manager (librte_mempool) <Mempool_Library>`
+and may be used as a general communication mechanism between cores
+and/or execution blocks connected together on a logical core.
+
+This ring buffer and its usage are fully described in :ref:`Ring Library <Ring_Library>`.
+
+Memory Pool Manager (librte_mempool)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The Memory Pool Manager is responsible for allocating pools of objects in memory.
+A pool is identified by name and uses a ring to store free objects.
+It provides some other optional services,
+such as a per-core object cache and an alignment helper to ensure that objects are padded to spread them equally on all RAM channels.
+
+This memory pool allocator is described in :ref:`Mempool Library <Mempool_Library>`.
+
+Network Packet Buffer Management (librte_mbuf)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The mbuf library provides the facility to create and destroy buffers
+that may be used by the DPDK application to store message buffers.
+The message buffers are created at startup time and stored in a mempool, using the DPDK mempool library.
+
+This library provide an API to allocate/free mbufs, manipulate control message buffers (ctrlmbuf) which are generic message buffers,
+and packet buffers (pktmbuf) which are used to carry network packets.
+
+Network Packet Buffer Management is described in :ref:`Mbuf Library <Mbuf_Library>`.
+
+Timer Manager (librte_timer)
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This library provides a timer service to DPDK execution units,
+providing the ability to execute a function asynchronously.
+It can be periodic function calls, or just a one-shot call.
+It uses the timer interface provided by the Environment Abstraction Layer (EAL)
+to get a precise time reference and can be initiated on a per-core basis as required.
+
+The library documentation is available in :ref:`Timer Library <Timer_Library>`.
+
+Ethernet* Poll Mode Driver Architecture
+---------------------------------------
+
+The DPDK includes Poll Mode Drivers (PMDs) for 1 GbE, 10 GbE and 40GbE, and para virtualized virtio
+Ethernet controllers which are designed to work without asynchronous, interrupt-based signaling mechanisms.
+
+See :ref:`Poll Mode Driver <Poll_Mode_Driver>`.
+
+Packet Forwarding Algorithm Support
+-----------------------------------
+
+The DPDK includes Hash (librte_hash) and Longest Prefix Match (LPM,librte_lpm)
+libraries to support the corresponding packet forwarding algorithms.
+
+See :ref:`Hash Library <Hash_Library>` and :ref:`LPM Library <LPM_Library>` for more information.
+
+librte_net
+----------
+
+The librte_net library is a collection of IP protocol definitions and convenience macros.
+It is based on code from the FreeBSD* IP stack and contains protocol numbers (for use in IP headers),
+IP-related macros, IPv4/IPv6 header structures and TCP, UDP and SCTP header structures.
Code Review / deb_dpdk.git / blobdiff