Commit 46879f71 authored by Matthew Gerlach's avatar Matthew Gerlach Committed by Greg Kroah-Hartman
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Documentation: fpga: dfl: Add documentation for DFHv1 



Add documentation describing the extensions provided by Version
1 of the Device Feature Header (DFHv1).

Signed-off-by: default avatarMatthew Gerlach <matthew.gerlach@linux.intel.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: default avatarTom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230115151447.1353428-2-matthew.gerlach@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2d762dab

Documentation/fpga/dfl.rst

+119 −0
Original line number Diff line number Diff line
@@ -75,6 +75,125 @@ 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.

All multi-byte quantities in DFHv0 are little-endian.

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.



All multi-byte quantities in DFHv1 are little-endian.

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