[PATCH] doc: add new driver guidelines

[Nandini Persad <nandinipersad361@gmail.com>]

This document was created to assist contributors in
creating DPDK drivers, providing suggestions and
guidelines on how to upstream effectively.

Signed-off-by: Ferruh Yigit <ferruh.yigit@amd.com>,
Thomas Monjalon <thomas@monjalon.net>,
Nandini Persad <nandinipersad361@gmail.com>
---
 0001-doc-add-new-driver-guidelines.patch | 206 +++++++++++++++++++++++
 doc/guides/contributing/index.rst        |   1 +
 2 files changed, 207 insertions(+)
 create mode 100644 0001-doc-add-new-driver-guidelines.patch

diff --git a/0001-doc-add-new-driver-guidelines.patch b/0001-doc-add-new-driver-guidelines.patch
new file mode 100644
index 0000000000..cba94a3789
--- /dev/null
+++ b/0001-doc-add-new-driver-guidelines.patch
@@ -0,0 +1,206 @@
++.. SPDX-License-Identifier: BSD-3-Clause
++   Copyright 2024 The DPDK contributors
++
++
++Upstreaming New DPDK Drivers Guide
++==================================
++
++The DPDK project continuously grows its ecosystem by adding support for new
++devices.
++This document is designed to assist contributors in creating DPDK
++drivers, also known as Poll Mode Drivers (PMD's).
++
++By having public support for a device, we can ensure accessibility across various
++operating systems and guarantee community maintenance in future releases.
++If a new device is similar to a device already supported by an existing driver,
++it is more efficient to update the existing driver.
++
++Here are our best practice recommendations for creating a new driver.
++
++
++Early Engagement with the Community
++-----------------------------------
++
++When creating a new driver, we highly recommend engaging with the DPDK
++community early instead of waiting the work to mature.
++
++These public discussions help align development of your driver with DPDK expectations.
++You may submit a roadmap before the release to inform the community of
++your plans. Additionally, sending a Request for Comments (RFC) early in
++the release cycle, or even during the prior release, is advisable.
++
++DPDK is mainly consumed via Long Term Support (LTS) releases.
++It is common to target a new PMD to a LTS release. For this, it is
++suggested to start upstreaming at least one release before a LTS release.
++
++
++Progressive Work
++----------------
++
++To continually progress your work, we recommend planning for incremental
++upstreaming across multiple patch series or releases.
++
++It's important to prioritize quality of the driver over upstreaming
++in a single release or single patch series.
++
++
++Finalizing
++----------
++
++Once the driver has been upstreamed, the author has
++a responsibility to the community to maintain it.
++
++This includes the public test report. Authors must send a public
++test report after the first upstreaming of the PMD. The same
++public test procedure may be reproduced regularly per release.
++
++After the PMD is upstreamed, the author should send a patch
++to update the website with the name of the new PMD and supported devices
++via the DPDK mailing list..
++
++For more information about the role of maintainers, see :doc:`patches.rst`.
++
++
++
++Splitting into Patches
++----------------------
++
++We recommend that drivers are split into patches, so that each patch represents
++a single feature. If the driver code is already developed, it may be challenging
++to split. However, there are many benefits to doing so.
++
++Splitting patches makes it easier to understand a feature and clarifies the
++list of components/files that compose that specific feature.
++
++It also enables the ability to track from the source code to the feature
++it is enabled for and helps users to understand the reasoning and intention
++of implementation. This kind of tracing is regularly required
++for defect resolution and refactoring.
++
++Another benefit of splitting the codebase per feature is that it highlights
++unnecessary or irrelevant code, as any code not belonging to any specific
++feature becomes obvious.
++
++Git bisect is also more useful if patches are split per patch.
++
++The split should focus on logical features
++rather than file-based divisions.
++
++Each patch in the series must compile without errors
++and should maintain functionality.
++
++Enable the build as early as possible within the series
++to facilitate continuous integration and testing.
++This approach ensures a clear and manageable development process.
++
++We suggest splitting patches following this approach:
++
++* Each patch should be organized logically as a new feature.
++* Run test tools per patch (See :ref:`tool_list`:).
++* Update relevant documentation and <driver>.ini file with each patch.
++
++
++The following order in the patch series is as suggested below.
++
++The first patch should have the driver's skeleton which should include:
++
++* Maintainer's file update
++* Driver documentation
++* Document must have links to official product documentation web page
++* The  new document should be added into the index (`doc/guides/index.rst`)
++* Initial <drive>.ini file
++* Release notes announcement for the new driver
++
++
++The next patches should include basic device features.
++The following is suggested sample list to include in these patches:
++
++=======================   ========================
++Net                       Crypto
++=======================   ========================
++Initialization            Initialization
++Configure queues          Configure queues
++Start queues              Start queues
++Simple Rx / Tx            Simple Data Processing
++Statistics                Statistics
++Device info
++Link interrupt 
++Burst mode info
++Promisc all-multicast
++RSS
++=======================   ========================
++
++
++Advanced features should be in the next group of patches.
++The suggestions for these, listed below, are in no specific order:
++
++=============================
++Net                      
++=============================  
++Advanced Rx / Tx
++Scatter Support
++Vector Support
++TSO / LRO
++Rx / Tx Descriptor Status
++RX / Tx Queue Info
++Flow Offload
++Traffic Management/Metering
++Extended statistics
++Secondary Process Support
++FreeBSD / Windows Support
++Flow control
++FEC
++EEPROM access
++Register Dump
++Time Synchronization, PTP
++Perf documentation
++=============================
++
++
++After all features are enabled, if there is remaining base code that
++is not upstreamed, they can be upstreamed at the end of the patch series.
++However, we recommend these patches are still split into logical groups.
++
++
++Additional Suggestions
++----------------------
++
++* We recommend using DPDK macros instead of inventing new ones in the PMD.
++* Do not include unused headers. Use the ./devtools/process-iwyu.py tool.
++* Do not disable compiler warnings in the build file.
++* Do not use #ifdef with driver-defined macros, instead prefer runtime configuration.
++* Document device parameters in the driver guide.
++* Make device operations struct 'const'.
++* Use dynamic logging.
++* Do not use DPDK version checks in the upstream code.
++* Be sure to have SPDX license tags and copyright notice on each side.
++
++
++Dependencies
++------------
++
++At times, drivers may have dependencies to external software.
++For driver dependencies, same DPDK rules for dependencies applies.
++Dependencies should be publicly and freely available,
++or this is a blocker for upstreaming the driver.
++
++
++.. _tool_list:
++
++Test Tools
++----------
++
++Be sure to run the following test tools per patch in a patch series:
++
++* checkpatches.sh
++* check-git-log.sh
++* check-meson.py
++* check-doc-vs-code.sh
++* check-spdx-tag.sh
++* Build documentation and validate how output looks
++
++For more information on contributing to DPDK,
++refer to :doc:`patches.rst`.
+-- 
+2.43.0
+
diff --git a/doc/guides/contributing/index.rst b/doc/guides/contributing/index.rst
index dcb9b1fbf0..7fc6511361 100644
--- a/doc/guides/contributing/index.rst
+++ b/doc/guides/contributing/index.rst
@@ -15,6 +15,7 @@ Contributor's Guidelines
     documentation
     unit_test
     new_library
+    new_driver
     patches
     vulnerability
     stable
-- 
2.34.1