Introduce a new function that abstracts finding information about a
region in IPA-local memory, given its memory region ID.  For now it
simply uses the region ID as an index into the IPA memory array.
If the region is not defined, ipa_mem_find() returns a null pointer.

Update all code that accesses the ipa->mem[] array directly to use
ipa_mem_find() instead.  The return value must be checked for null
when optional memory regions are sought.

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

Do some general cleanup in ipa_cmd_header_valid():
  - Delay assigning the mem variable until just before it's used.
  - Assign the maximum offset and size values together.
  - Improve comments explaining the single range of memory being
    made up of a modem portion and an AP portion.
  - Record the offset of the combined range in a local variable.
  - Do the initial size assignment right after assigning the offset.

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

Entries in an IPA route or filter table are 64-bit little-endian
addresses, each of which refers to a routing or filtering rule.

The format of these table slots are fixed, but IPA_TABLE_ENTRY_SIZE
is used to define their size.  This symbol doesn't really add value,
and I think it unnecessarily obscures what a table entry *is*.

So get rid of IPA_TABLE_ENTRY_SIZE, and just use sizeof(__le64) in
its place throughout the code.

Update the comments in "ipa_table.c" to provide a little better
explanation of these table slots.

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

Signed-off-by: David S. Miller <davem@davemloft.net>

Modify conditional tests throughout the IPA code so they do not
assume that IPA v3.5.1 is the oldest version supported.  Also remove
assumptions that IPA v4.5 is the newest version of IPA supported.

Augment versions in comments with "+", to be clearer that the
comment applies to a version and subsequent versions.  (E.g.,
"present for IPA v4.2+" instead of just "present for v4.2".)

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

We use ipa_cmd_header_valid() to ensure certain values we will
program into hardware are within range, well in advance of when we
actually program them.  This way we avoid having to check for errors
when we actually program the hardware.

Unfortunately the dev_err() call for a bad offset value does not
supply the arguments to match the format specifiers properly.
Fix this.

There was also supposed to be a check to ensure the size to be
programmed fits in the field that holds it.  Add this missing check.

Rearrange the way we ensure the header table fits in overall IPA
memory range.

Finally, update ipa_cmd_table_valid() so the format of messages
printed for errors matches what's done in ipa_cmd_header_valid().

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

Introduce a new function to abstract the knowledge of whether hashed
routing and filter tables are supported for a given IPA instance.

IPA v4.2 is the only one that doesn't support hashed tables (now
and for the foreseeable future), but the name of the helper function
is better for explaining what's going on.

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

In ipa_cmd_register_write_valid() we verify that values we will
supply to a REGISTER_WRITE IPA immediate command will fit in
the fields that need to hold them.  This patch fixes some issues
in that function and ipa_cmd_register_write_offset_valid().

The dev_err() call in ipa_cmd_register_write_offset_valid() has
some printf format errors:
  - The name of the register (corresponding to the string format
    specifier) was not supplied.
  - The IPA base offset and offset need to be supplied separately to
    match the other format specifiers.
Also make the ~0 constant used there to compute the maximum
supported offset value explicitly unsigned.

There are two other issues in ipa_cmd_register_write_valid():
  - There's no need to check the hash flush register for platforms
    (like IPA v4.2) that do not support hashed tables
  - The highest possible endpoint number, whose status register
    offset is computed, is COUNT - 1, not COUNT.

Fix these problems, and add some additional commentary.

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

The only time we transfer data (rather than issuing a command) out
of the AP->command TX endpoint is when we're clearing the hardware
pipeline.  All that's needed is a "small" data buffer, and its
contents aren't even important.

For convenience, we just transfer a command structure in this case
(it's already mapped for DMA).  The TRE is added to a transaction
using ipa_cmd_ip_tag_status_add(), but we ignore the size value
provided to that function.  So just get rid of the size argument.

Signed-off-by: Alex Elder <elder@linaro.org>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We only send a tagged packet from the AP->command TX endpoint when
we're clearing the hardware pipeline.  And when we receive the
tagged packet we don't care what the actual tag value is.

Stop passing a tag value to ipa_cmd_ip_tag_status_add(), and just
encode 0 as the tag sent.  Fix the function that encodes the tag so
it uses the proper byte ordering.

Signed-off-by: Alex Elder <elder@linaro.org>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>