Re: [PATCH v9 1/4] Documentation: fpga: dfl: Add documentation for DFHv1

[Tom Rix <trix@redhat.com>]

On 1/4/23 3:22 PM, matthew.gerlach@linux.intel.com wrote:
> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>
> Add documentation describing the extensions provided by Version
> 1 of the Device Feature Header (DFHv1).
>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Thanks for the changes.

Reviewed-by: Tom Rix <trix@redhat.com>

> ---
> v9: move DFH definitions to after the Overview
>      fix name of feature revision field
>      clarify next field in DFH
>
> v8: fix section titles
>
> v7: shorten long lines and wording suggestions by bagasdotme@gmail.com
>
> v6: no change
>
> v5: use nested list for field descriptions
>      clean up prose
>      add reviewed-by and comments from Ilpo Järvinen
>
> v4: Remove marketing speak and separate v0 and v1 descriptions.
>      Fix errors reported by "make htmldocs".
>
> v3: no change
>
> v2: s/GUILD/GUID/
>      add picture
> ---
>   Documentation/fpga/dfl.rst | 117 +++++++++++++++++++++++++++++++++++++
>   1 file changed, 117 insertions(+)
>
> diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
> index 15b670926084..7e015249785b 100644
> --- a/Documentation/fpga/dfl.rst
> +++ b/Documentation/fpga/dfl.rst
> @@ -75,6 +75,123 @@ convenient for software to locate each feature by walking through this list,
>   and can be implemented in register regions of any FPGA device.
>   
>   
> +Device Feature Header - Version 0
> +=================================
> +Version 0 (DFHv0) is the original version of the Device Feature Header.
> +The format of DFHv0 is shown below::
> +
> +    +-----------------------------------------------------------------------+
> +    |63 Type 60|59 DFH VER 52|51 Rsvd 41|40 EOL|39 Next 16|15 REV 12|11 ID 0| 0x00
> +    +-----------------------------------------------------------------------+
> +    |63                                 GUID_L                             0| 0x08
> +    +-----------------------------------------------------------------------+
> +    |63                                 GUID_H                             0| 0x10
> +    +-----------------------------------------------------------------------+
> +
> +- Offset 0x00
> +
> +  * Type - The type of DFH (e.g. FME, AFU, or private feature).
> +  * DFH VER - The version of the DFH.
> +  * Rsvd - Currently unused.
> +  * EOL - Set if the DFH is the end of the Device Feature List (DFL).
> +  * Next - The offset in bytes of the next DFH in the DFL from the DFH start,
> +    and the start of a DFH must be aligned to an 8 byte boundary.
> +    If EOL is set, Next is the size of MMIO of the last feature in the list.
> +  * REV - The revision of the feature associated with this header.
> +  * ID - The feature ID if Type is private feature.
> +
> +- Offset 0x08
> +
> +  * GUID_L - Least significant 64 bits of a 128-bit Globally Unique Identifier
> +    (present only if Type is FME or AFU).
> +
> +- Offset 0x10
> +
> +  * GUID_H - Most significant 64 bits of a 128-bit Globally Unique Identifier
> +    (present only if Type is FME or AFU).
> +
> +
> +Device Feature Header - Version 1
> +=================================
> +Version 1 (DFHv1) of the Device Feature Header adds the following functionality:
> +
> +* Provides a standardized mechanism for features to describe
> +  parameters/capabilities to software.
> +* Standardize the use of a GUID for all DFHv1 types.
> +* Decouples the DFH location from the register space of the feature itself.
> +
> +The format of Version 1 of the Device Feature Header (DFH) is shown below::
> +
> +    +-----------------------------------------------------------------------+
> +    |63 Type 60|59 DFH VER 52|51 Rsvd 41|40 EOL|39 Next 16|15 REV 12|11 ID 0| 0x00
> +    +-----------------------------------------------------------------------+
> +    |63                                 GUID_L                             0| 0x08
> +    +-----------------------------------------------------------------------+
> +    |63                                 GUID_H                             0| 0x10
> +    +-----------------------------------------------------------------------+
> +    |63                   Reg Address/Offset                      1|  Rel  0| 0x18
> +    +-----------------------------------------------------------------------+
> +    |63        Reg Size       32|Params 31|30 Group    16|15 Instance      0| 0x20
> +    +-----------------------------------------------------------------------+
> +    |63 Next    35|34RSV33|EOP32|31 Param Version 16|15 Param ID           0| 0x28
> +    +-----------------------------------------------------------------------+
> +    |63                 Parameter Data                                     0| 0x30
> +    +-----------------------------------------------------------------------+
> +
> +                                  ...
> +
> +    +-----------------------------------------------------------------------+
> +    |63 Next    35|34RSV33|EOP32|31 Param Version 16|15 Param ID           0|
> +    +-----------------------------------------------------------------------+
> +    |63                 Parameter Data                                     0|
> +    +-----------------------------------------------------------------------+
> +
> +- Offset 0x00
> +
> +  * Type - The type of DFH (e.g. FME, AFU, or private feature).
> +  * DFH VER - The version of the DFH.
> +  * Rsvd - Currently unused.
> +  * EOL - Set if the DFH is the end of the Device Feature List (DFL).
> +  * Next - The offset in bytes of the next DFH in the DFL from the DFH start,
> +    and the start of a DFH must be aligned to an 8 byte boundary.
> +    If EOL is set, Next is the size of MMIO of the last feature in the list.
> +  * REV - The revision of the feature associated with this header.
> +  * ID - The feature ID if Type is private feature.
> +
> +- Offset 0x08
> +
> +  * GUID_L - Least significant 64 bits of a 128-bit Globally Unique Identifier.
> +
> +- Offset 0x10
> +
> +  * GUID_H - Most significant 64 bits of a 128-bit Globally Unique Identifier.
> +
> +- Offset 0x18
> +
> +  * Reg Address/Offset - If Rel bit is set, then the value is the high 63 bits
> +    of a 16-bit aligned absolute address of the feature's registers. Otherwise
> +    the value is the offset from the start of the DFH of the feature's registers.
> +
> +- Offset 0x20
> +
> +  * Reg Size - Size of feature's register set in bytes.
> +  * Params - Set if DFH has a list of parameter blocks.
> +  * Group - Id of group if feature is part of a group.
> +  * Instance - Id of feature instance within a group.
> +
> +- Offset 0x28 if feature has parameters
> +
> +  * Next - Offset to the next parameter block in 8 byte words. If EOP set,
> +    size in 8 byte words of last parameter.
> +  * Param Version - Version of Param ID.
> +  * Param ID - ID of parameter.
> +
> +- Offset 0x30
> +
> +  * Parameter Data - Parameter data whose size and format is defined by
> +    version and ID of the parameter.
> +
> +
>   FIU - FME (FPGA Management Engine)
>   ==================================
>   The FPGA Management Engine performs reconfiguration and other infrastructure