On Fri, 23 Sep 2022, matthew.gerlach@xxxxxxxxxxxxxxx wrote: > From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx> > > Add documentation describing the extensions provided by Version > 1 of the Device Feature Header (DFHv1). > > Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx> > --- > v2: s/GUILD/GUID/ > add picture > --- > Documentation/fpga/dfl.rst | 49 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 49 insertions(+) > > diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst > index 15b670926084..7c786b75b498 100644 > --- a/Documentation/fpga/dfl.rst > +++ b/Documentation/fpga/dfl.rst > @@ -561,6 +561,55 @@ new DFL feature via UIO direct access, its feature id should be added to the > driver's id_table. > > > +Extending the Device Feature Header - DFHv1 > +=========================================== > +The current 8 bytes of the Device Feature Header, hereafter referred to as > +to DFHv0, provide very little opportunity for the hardware to describe itself > +to software. Version 1 of the Device Feature Header (DFHv1) is being introduced > +to provide increased flexibility and extensibility to hardware designs using > +Device Feature Lists. The list below describes some of the goals behind the > +changes in DFHv1: > + > +* Provide a standardized mechanism for features to describe > + parameters/capabilities to software. > +* Standardize the use of a GUID for all DFHv1 types. > +* Decouple the location of the DFH from the register space of the feature itself. > + > +Modeled after PCI Capabilities, DFHv1 Parameters provide a mechanism to associate > +a list of parameter values to a particular feature. > + > +With DFHv0, not all features types contained a GUID. DFHv1 makes the GUID standard > +across all types. > + > +With DFHv0, the register map of a given feature is located immediately following > +the DFHv0 in the memory space. With DFHv1, the location of the feature register > +map can be specified as an offset to the DFHv1 or as an absolute address. The DFHv1 > +structure is shown below: > + > + +-----------------------------------------------------------------------+ > + |63 Type 60|59 DFH VER 52|51 Rsvd 41|40 EOL|39 Next 16|15 VER 12|11 ID 0| > + +-----------------------------------------------------------------------+ > + |63 GUID_L 0| > + +-----------------------------------------------------------------------+ > + |63 GUID_H 0| > + +-----------------------------------------------------------------------+ > + |63 Address/Offset 1| Rel 0| > + +-----------------------------------------------------------------------+ Is something missing here given the layout is claimed (in 2/6) to be: "DFHv1 Register Offset definitons In DHFv1, DFH + GUID + CSR_START + CSR_SIZE_GROUP + PARAM_HDR + PARAM_DATA" ? > + |63 Size of register set 32|Params 31|30 Group 16|15 Instance 0| > + +-----------------------------------------------------------------------+ > + |63 Next parameter offset 32|31 Param Version 16|15 Param ID 0| > + +-----------------------------------------------------------------------+ > + |63 Parameter Data 0| > + +-----------------------------------------------------------------------+ > + > + ... > + > + +-----------------------------------------------------------------------+ > + |63 Next parameter offset 32|31 Param Version 16|15 Param ID 0| > + +-----------------------------------------------------------------------+ > + |63 Parameter Data 0| > + +-----------------------------------------------------------------------+ > + > Open discussion > =============== > FME driver exports one ioctl (DFL_FPGA_FME_PORT_PR) for partial reconfiguration > -- i.
