Signed-off-by: Shreyansh Jain <shreyansh.j...@nxp.com>
---
doc/guides/prog_guide/index.rst | 1 +
doc/guides/prog_guide/rawdev_lib.rst | 83 ++++++++++++++++++++++++++++++++++++
2 files changed, 84 insertions(+)
create mode 100644 doc/guides/prog_guide/rawdev_lib.rst
diff --git a/doc/guides/prog_guide/index.rst b/doc/guides/prog_guide/index.rst
index af5f65a33..beead3105 100644
--- a/doc/guides/prog_guide/index.rst
+++ b/doc/guides/prog_guide/index.rst
@@ -75,6 +75,7 @@ Programmer's Guide
vhost_lib
metrics_lib
port_hotplug_framework
+ rawdev_lib
source_org
dev_kit_build_system
dev_kit_root_make_help
diff --git a/doc/guides/prog_guide/rawdev_lib.rst
b/doc/guides/prog_guide/rawdev_lib.rst
new file mode 100644
index 000000000..d21d284ca
--- /dev/null
+++ b/doc/guides/prog_guide/rawdev_lib.rst
@@ -0,0 +1,83 @@
+.. SPDX-License-Identifier: BSD-3-Clause
+ Copyright 2018 NXP
+
+Rawdevice Library
+=================
+
+Introduction
+------------
+
+In terms of device flavor (type) support, DPDK currently has ethernet
+(lib_ether), cryptodev (libcryptodev), eventdev (libeventdev) and vdev
+(virtual device) support.
+
+For a new type of device, for example an accelerator, there are not many
+options except:
+1. create another lib/librte_MySpecialDev, driver/MySpecialDrv and use it
+through Bus/PMD model.
+2. Or, create a vdev and implement necessary custom APIs which are directly
+exposed from driver layer. However this may still require changes in bus code
+in DPDK.
+
+The DPDK Rawdev library is an abstraction that provides the DPDK framework a
+way to manage such devices in a generic manner without expecting changes to
+library or EAL for each device type. This library provides a generic set of
+operations and APIs for framework and Applications to use, respectively, for
+interfacing with such type of devices.
+
+Design
+------
+
+Key factors guiding design of the Rawdevice library:
+
+1. Following are some generic operations which can be treated as applicable
+ to a large subset of device types. None of the operations are mandatory to
+ be implemented by a driver. Application should also be design for proper
+ handling for unsupported APIs.
+
+ * Device Start/Stop - In some cases, 'reset' might also be required which
+ has different semantics than a start-stop-start cycle.
+ * Configuration - Device, Queue or any other sub-system configuration
+ * I/O - Sending a series of buffers which can enclose any arbitrary data
+ * Statistics - Fetch arbitrary device statistics
+ * Firmware Management - Firmware load/unload/status
+
+2. Application API should be able to pass along arbitrary state information
+ to/fro device driver. This can be achieved by maintaining context
+ information through opaque data or pointers.
+
+Figure below outlines the layout of the rawdevice library and device vis-a-vis
+other well known device types like eth and crypto:
+
+.. code-block:: console
+
+ +-----------------------------------------------------------+
+ | Application(s) |
+ +------------------------------.----------------------------+
+ |
+ |
+ +------------------------------'----------------------------+
+ | DPDK Framework (APIs) |
+ +--------------|----|-----------------|---------------------+
+ / \ \
+ (crypto ops) (eth ops) (rawdev ops) +----+
+ / \ \ |DrvA|
+ +-----'---+ +----`----+ +---'-----+ +----+
+ | crypto | | ethdev | | raw |
+ +--/------+ +---/-----+ +----/----+ +----+
+ /\ __/\ / ..........|DrvB|
+ / \ / \ / ../ \ +----+
+ +====+ +====+ +====+ +====+ +==/=+ ```Bus Probe
+ |DevA| |DevB| |DevC| |DevD| |DevF|
+ +====+ +====+ +====+ +====+ +====+
+ | | | | |
+ ``|``````|````````|``````|`````````````````|````````Bus Scan
+ (PCI) | (PCI) (PCI) (PCI)
+ (BusA)
+
+ * It is assumed above that DrvB is a PCI type driver which registers itself
+ with PCI Bus
+ * Thereafter, when the PCI scan is done, during probe DrvB would match the
+ rawdev DevF ID and take control of device
+ * Applications can then continue using the device through rawdev API
+ interfaces
--
2.14.1
