Establish the rule that header files are always included in sorted
(POSIX local) order.  Standard and private headers are separated by
a blank line.

Similarly, sort all forward-declarations for structures.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

As definitions in headers have been moved around, some of the
struct and enum declarations found in header files have become
no longer necessary and can be removed.  Remove these unneeded
declarations.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Some source files state copyright dates that are earlier than the
last modification of the file.  Change the copyright year to 2022 in
all such cases.

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224549.3503434-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This patch just updates comments throughout the IPA code.

Transaction state is now tracked using indexes into an array rather
than linked lists, and a few comments refer to the "old way" of
doing things.  The description of how transactions are used was
changed to refer to "operations" rather than "commands", to
(hopefully) remove a possible ambiguity.

IPA register offsets and fields are now handled differently as well,
and the register documentation is updated to better describe the
code.

A few minor updates to comments were made (e.g., adding a missing
word, fixing a typo or punctuation, etc.).

Finally, the local macro atomic_dec_not_zero() is no longer used, so
it is deleted.

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224527.3503404-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

None of the transaction lists are actually needed any more, because
transaction IDs (which have been shown to be equivalent) are used
instead.  So we can remove all of them, as well as the spinlock
that protects updates to them.

Not requiring a lock simplifies gsi_trans_free() as well; we only
need to check the reference count once to decide whether we've hit
the last reference.

This makes the links field in the gsi_trans structure unused, so get
rid of that as well.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Create a new function that encapsulates recording information needed
for TX channel statistics when a transaction is committed.

Record the accumulated length in the transaction before the call
(for both RX and TX), so it can be used when updating TX statistics.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

There are two fields in a GSI transaction that keep track of TRE
counts.  The first represents the number of TREs reserved for the
transaction in the TRE ring; that's currently named "tre_count".
The second is the number of TREs that are actually *used* by the
transaction at the time it is committed.

Rename the "tre_count" field to be "rsvd_count", to make its meaning
a little more specific.  The "_count" is present in the name mainly
to avoid interpreting it as a reserved (not-to-be-used) field.  This
name also distinguishes it from the "tre_count" field associated
with a channel.

Rename the "used" field to be "used_count", to match the convention
used for reserved TREs.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 64-bit data field in a transaction is not used for commands.
And the opcode array is *only* used for commands.  They're
(currently) the same size; save a little space in the transaction
structure by enclosing the two fields in a union.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ipa_cmd_info structure now contains only one field, and it's an
enumerated type whose values all fit in 8 bits.  Currently we'll
never use more than 8 TREs in a command transaction, and we can
represent that number of command opcodes in the same space as a 64
bit pointer to an ipa_cmd_info structure.

Define IPA_COMMAND_TRANS_TRE_MAX as the maximum number of TREs that
can be in a command transaction.  Replace the info pointer in a
transaction with a fixed-size array named cmd_opcode[] of that many
bytes.  Store the opcode in this array when adding a command TRE to
a transaction, as was done previously for the info array.  This
makes the ipa_cmd_info unused, so get rid of it.

When committing an immediate command transaction, use the channel's
Boolean command flag to determine whether to fill in the opcode,
which will be taken (as before) from the array in the transaction.

This makes the command info pool unnecessary, so get rid of it.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

We no longer use the direction argument for gsi_trans_cmd_add(), so
get rid of it in its definition, and in its seven callers.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>