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-rw-r--r--Documentation/driver-api/pldmfw/driver-ops.rst56
-rw-r--r--Documentation/driver-api/pldmfw/file-format.rst203
-rw-r--r--Documentation/driver-api/pldmfw/index.rst72
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diff --git a/Documentation/driver-api/pldmfw/driver-ops.rst b/Documentation/driver-api/pldmfw/driver-ops.rst
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+.. SPDX-License-Identifier: GPL-2.0-only
+
+=========================
+Driver-specific callbacks
+=========================
+
+The ``pldmfw`` module relies on the device driver for implementing device
+specific behavior using the following operations.
+
+``.match_record``
+-----------------
+
+The ``.match_record`` operation is used to determine whether a given PLDM
+record matches the device being updated. This requires comparing the record
+descriptors in the record with information from the device. Many record
+descriptors are defined by the PLDM standard, but it is also allowed for
+devices to implement their own descriptors.
+
+The ``.match_record`` operation should return true if a given record matches
+the device.
+
+``.send_package_data``
+----------------------
+
+The ``.send_package_data`` operation is used to send the device-specific
+package data in a record to the device firmware. If the matching record
+provides package data, ``pldmfw`` will call the ``.send_package_data``
+function with a pointer to the package data and with the package data
+length. The device driver should send this data to firmware.
+
+``.send_component_table``
+-------------------------
+
+The ``.send_component_table`` operation is used to forward component
+information to the device. It is called once for each applicable component,
+that is, for each component indicated by the matching record. The
+device driver should send the component information to the device firmware,
+and wait for a response. The provided transfer flag indicates whether this
+is the first, last, or a middle component, and is expected to be forwarded
+to firmware as part of the component table information. The driver should an
+error in the case when the firmware indicates that the component cannot be
+updated, or return zero if the component can be updated.
+
+``.flash_component``
+--------------------
+
+The ``.flash_component`` operation is used to inform the device driver to
+flash a given component. The driver must perform any steps necessary to send
+the component data to the device.
+
+``.finalize_update``
+--------------------
+
+The ``.finalize_update`` operation is used by the ``pldmfw`` library in
+order to allow the device driver to perform any remaining device specific
+logic needed to finish the update.
diff --git a/Documentation/driver-api/pldmfw/file-format.rst b/Documentation/driver-api/pldmfw/file-format.rst
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+.. SPDX-License-Identifier: GPL-2.0-only
+
+==================================
+PLDM Firmware file format overview
+==================================
+
+A PLDM firmware package is a binary file which contains a header that
+describes the contents of the firmware package. This includes an initial
+package header, one or more firmware records, and one or more components
+describing the actual flash contents to program.
+
+This diagram provides an overview of the file format::
+
+ overall file layout
+ +----------------------+
+ | |
+ | Package Header |
+ | |
+ +----------------------+
+ | |
+ | Device Records |
+ | |
+ +----------------------+
+ | |
+ | Component Info |
+ | |
+ +----------------------+
+ | |
+ | Package Header CRC |
+ | |
+ +----------------------+
+ | |
+ | Component Image 1 |
+ | |
+ +----------------------+
+ | |
+ | Component Image 2 |
+ | |
+ +----------------------+
+ | |
+ | ... |
+ | |
+ +----------------------+
+ | |
+ | Component Image N |
+ | |
+ +----------------------+
+
+Package Header
+==============
+
+The package header begins with the UUID of the PLDM file format, and
+contains information about the version of the format that the file uses. It
+also includes the total header size, a release date, the size of the
+component bitmap, and an overall package version.
+
+The following diagram provides an overview of the package header::
+
+ header layout
+ +-------------------------+
+ | PLDM UUID |
+ +-------------------------+
+ | Format Revision |
+ +-------------------------+
+ | Header Size |
+ +-------------------------+
+ | Release Date |
+ +-------------------------+
+ | Component Bitmap Length |
+ +-------------------------+
+ | Package Version Info |
+ +-------------------------+
+
+Device Records
+==============
+
+The device firmware records area starts with a count indicating the total
+number of records in the file, followed by each record. A single device
+record describes what device matches this record. All valid PLDM firmware
+files must contain at least one record, but optionally may contain more than
+one record if they support multiple devices.
+
+Each record will identify the device it supports via TLVs that describe the
+device, such as the PCI device and vendor information. It will also indicate
+which set of components that are used by this device. It is possible that
+only subset of provided components will be used by a given record. A record
+may also optionally contain device-specific package data that will be used
+by the device firmware during the update process.
+
+The following diagram provides an overview of the device record area::
+
+ area layout
+ +---------------+
+ | |
+ | Record Count |
+ | |
+ +---------------+
+ | |
+ | Record 1 |
+ | |
+ +---------------+
+ | |
+ | Record 2 |
+ | |
+ +---------------+
+ | |
+ | ... |
+ | |
+ +---------------+
+ | |
+ | Record N |
+ | |
+ +---------------+
+
+ record layout
+ +-----------------------+
+ | Record Length |
+ +-----------------------+
+ | Descriptor Count |
+ +-----------------------+
+ | Option Flags |
+ +-----------------------+
+ | Version Settings |
+ +-----------------------+
+ | Package Data Length |
+ +-----------------------+
+ | Applicable Components |
+ +-----------------------+
+ | Version String |
+ +-----------------------+
+ | Descriptor TLVs |
+ +-----------------------+
+ | Package Data |
+ +-----------------------+
+
+Component Info
+==============
+
+The component information area begins with a count of the number of
+components. Following this count is a description for each component. The
+component information points to the location in the file where the component
+data is stored, and includes version data used to identify the version of
+the component.
+
+The following diagram provides an overview of the component area::
+
+ area layout
+ +-----------------+
+ | |
+ | Component Count |
+ | |
+ +-----------------+
+ | |
+ | Component 1 |
+ | |
+ +-----------------+
+ | |
+ | Component 2 |
+ | |
+ +-----------------+
+ | |
+ | ... |
+ | |
+ +-----------------+
+ | |
+ | Component N |
+ | |
+ +-----------------+
+
+ component layout
+ +------------------------+
+ | Classification |
+ +------------------------+
+ | Component Identifier |
+ +------------------------+
+ | Comparison Stamp |
+ +------------------------+
+ | Component Options |
+ +------------------------+
+ | Activation Method |
+ +------------------------+
+ | Location Offset |
+ +------------------------+
+ | Component Size |
+ +------------------------+
+ | Component Version Info |
+ +------------------------+
+ | Package Data |
+ +------------------------+
+
+
+Package Header CRC
+==================
+
+Following the component information is a short 4-byte CRC calculated over
+the contents of all of the header information.
+
+Component Images
+================
+
+The component images follow the package header information in the PLDM
+firmware file. Each of these is simply a binary chunk with its start and
+size defined by the matching component structure in the component info area.
diff --git a/Documentation/driver-api/pldmfw/index.rst b/Documentation/driver-api/pldmfw/index.rst
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+.. SPDX-License-Identifier: GPL-2.0-only
+
+==================================
+PLDM Firmware Flash Update Library
+==================================
+
+``pldmfw`` implements functionality for updating the flash on a device using
+the PLDM for Firmware Update standard
+<https://www.dmtf.org/documents/pmci/pldm-firmware-update-specification-100>.
+
+.. toctree::
+ :maxdepth: 1
+
+ file-format
+ driver-ops
+
+==================================
+Overview of the ``pldmfw`` library
+==================================
+
+The ``pldmfw`` library is intended to be used by device drivers for
+implementing device flash update based on firmware files following the PLDM
+firwmare file format.
+
+It is implemented using an ops table that allows device drivers to provide
+the underlying device specific functionality.
+
+``pldmfw`` implements logic to parse the packed binary format of the PLDM
+firmware file into data structures, and then uses the provided function
+operations to determine if the firmware file is a match for the device. If
+so, it sends the record and component data to the firmware using the device
+specific implementations provided by device drivers. Once the device
+firmware indicates that the update may be performed, the firmware data is
+sent to the device for programming.
+
+Parsing the PLDM file
+=====================
+
+The PLDM file format uses packed binary data, with most multi-byte fields
+stored in the Little Endian format. Several pieces of data are variable
+length, including version strings and the number of records and components.
+Due to this, it is not straight forward to index the record, record
+descriptors, or components.
+
+To avoid proliferating access to the packed binary data, the ``pldmfw``
+library parses and extracts this data into simpler structures for ease of
+access.
+
+In order to safely process the firmware file, care is taken to avoid
+unaligned access of multi-byte fields, and to properly convert from Little
+Endian to CPU host format. Additionally the records, descriptors, and
+components are stored in linked lists.
+
+Performing a flash update
+=========================
+
+To perform a flash update, the ``pldmfw`` module performs the following
+steps
+
+1. Parse the firmware file for record and component information
+2. Scan through the records and determine if the device matches any record
+ in the file. The first matched record will be used.
+3. If the matching record provides package data, send this package data to
+ the device.
+4. For each component that the record indicates, send the component data to
+ the device. For each component, the firmware may respond with an
+ indication of whether the update is suitable or not. If any component is
+ not suitable, the update is canceled.
+5. For each component, send the binary data to the device firmware for
+ updating.
+6. After all components are programmed, perform any final device-specific
+ actions to finalize the update.