Merge branch 'net-ipa-generalized-register-definitions'

Alex Elder says:

====================
net: ipa: generalized register definitions

This series is quite a bit bigger than what I normally like to send,
and I apologize for that.  I would like it to get incorporated in
its entirety this week if possible, and splitting up the series
carries a small risk that wouldn't happen.

Each IPA register has a defined offset, and in most cases, a set
of masks that define the width and position of fields within the
register.  Most registers currently use the same offset for all
versions of IPA.  Usually fields within registers are also the same
across many versions.  Offsets and fields like this are defined
using preprocessor constants.

When a register has a different offset for different versions of
IPA, an inline function is used to determine its offset.  And in
places where a field differs between versions, an inline function is
used to determine how a value is encoded within the field, depending
on IPA version.

Starting with IPA version 5.0, the number of IPA endpoints supported
is greater than 32.  As a consequence, *many* IPA register offsets
differ considerably from prior versions.  This increase in endpoints
also requires a lot of field sizes and/or positions to change (such
as those that contain an endpoint ID).

Defining these things with constants is no longer simple, and rather
than fill the code with one-off functions to define offsets and
encode field values, this series puts in place a new way of defining
IPA registers and their fields.  Note that this series creates this
new scheme, but does not add IPA v5.0+ support.

An enumerated type will now define a unique ID for each IPA register.
Each defined register will have a structure that contains its offset
and its name (a printable string).  Each version of IPA will have an
array of these register structures, indexed by register ID.

Some "parameterized" registers are duplicated (this is not new).
For example, each endpoint has an INIT_HDR register, and the offset
of a given endpoint's INIT_HDR register is dependent on the endpoint
number (the parameter).  In such cases, the register's "stride" is
defined as the distance between two of these registers.

If a register contains fields, each field will have a unique ID
that's used as an index into an array of field masks defined for the
register.  The register structure also defines the number of entries
in this field array.

When a register is to be used in code, its register structure will
be fetched using function ipa_reg().  Other functions are then used
to determine the register's offset, or to encode a value into one of
the register's fields, and so on.

Each version of IPA defines the set of registers that are available,
including all fields for these registers.  The array of defined
registers is set up at probe time based on the IPA version, and it
is associated with the main IPA structure.
====================

Link: https://lore.kernel.org/r/20220926220931.3261749-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>