The trans_tre_max field of the IPA endpoint structure is only used
to limit the number of fragments allowed for an SKB being prepared
for transmission.  Recognizing that, rename the field skb_frag_max,
and reduce its value by 1.

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

Don't assume that a 500 microsecond time limit should be used for
all receive endpoints that support aggregation.  Instead, specify
the time limit to use in the configuration data.

Set a 500 microsecond limit for all existing RX endpoints, as before.

Checking for overflow for the time limit field is a bit complicated.
Rather than duplicate a lot of code in ipa_endpoint_data_valid_one(),
call WARN() if any value is found to be too large when encoding it.

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

Add a new flag for AP receive endpoints that indicates whether
a "hard limit" is used as a criterion for closing aggregation.
Add comments explaining the difference between "hard" and "soft"
aggregation limits.

Pass a flag to ipa_aggr_size_kb() so it computes the proper
aggregation size value whether using hard or soft limits.  Move
that function earlier in "ipa_endpoint.c" so it can be used
without a forward-reference.

Update ipa_endpoint_data_valid_one() so it validates endpoints whose
data indicate a hard aggregation limit is used, and so it reports
set aggregation flags for endpoints without aggregation enabled.

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

Add a new Boolean flag for RX endpoints defining whether HOLB drop
is initially enabled or disabled for the endpoint.  All existing AP
endpoints should have HOLB drop disabled.

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

All elements of the default endpoint configuration are used in the
code when programming an endpoint for use.  But none of the other
configuration data is ever needed once things are initialized.

So rather than saving a pointer to *all* of the configuration data,
save a copy of only the endpoint configuration portion.

This will eventually allow endpoint configuration to be modifiable
at runtime.  But even before that it means we won't keep a pointer
to configuration data after when no longer needed.

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

Rename the just-moved data structure types to drop the "_data"
suffix, to make it more obvious they are no longer meant to be used
just as read-only initialization data.  Rename the fields and
variables of these types to use "config" instead of "data" in the
name.  This is another small step meant to facilitate review.

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

Move the definitions of the structures defining endpoint-specific
configuration data out of "ipa_data.h" and into "ipa_endpoint.h".
This is a trivial movement of code without any other change, to
prepare for the next few patches.

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

Rather than tracking the number of receive buffer transactions that
have been submitted without a doorbell, just track the total number
of transactions that have been issued.  Then ring the doorbell when
that number modulo the replenish batch size is 0.

The effect is roughly the same, but the new count is slightly more
interesting, and this approach will someday allow the replenish
batch size to be tuned at runtime.

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

We no longer use the replenish_backlog atomic variable to decide
when we've got work to do providing receive buffers to hardware.
Basically, we try to keep the hardware as full as possible, all the
time.  We keep supplying buffers until the hardware has no more
space for them.

As a result, we can get rid of the replenish_backlog field and the
atomic operations performed on it.

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

The replenish_saved field keeps track of the number of times a new
buffer is added to the backlog when replenishing is disabled.  We
don't really use it though, so there's no need for us to track it
separately.  Whether replenishing is enabled or not, we can simply
increment the backlog.

Get rid of replenish_saved, and initialize and increment the backlog
where it would have otherwise been used.

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