net: ipa: introduce ipa_cmd_init()

Currently, ipa_cmd_data_valid() is called by ipa_mem_config().
Nothing it does requires access to hardware though, so it can be
done during the init phase of IPA driver startup.

Create a new function ipa_cmd_init(), whose purpose is to do early
initialization related to IPA immediate commands. It will call the
build-time validation function, then will make the two calls made
previously by ipa_cmd_data_valid(). This make ipa_cmd_data_valid()
unnecessary, so get rid of it.

Rename ipa_cmd_header_valid() to be ipa_cmd_header_init_local_valid(),
so its name is clearer about which IPA immediate command it is
associated with.

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

net: ipa: verify table sizes fit in commands early

We currently verify the table size and offset fit in the immediate
command fields that must encode them in ipa_table_valid_one(). We
can now make this check earlier, in ipa_table_mem_valid().

The non-hashed IPv4 filter and route tables will always exist, and
their sizes will match the IPv6 tables, as well as the hashed tables
(if supported). So it's sufficient to verify the offset and size of
the IPv4 non-hashed tables fit into these fields.

Rename the function ipa_cmd_table_init_valid(), to reinforce that
it is the TABLE_INIT immediate command fields we're checking.

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

net: ipa: update copyrights

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>

net: ipa: remove command info pool

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>

net: ipa: get rid of ipa_cmd_info->direction

The direction field of the ipa_cmd_info structure is set, but never
used. It seems it might have been used for the DMA_SHARED_MEM
immediate command, but the DIRECTION flag is set based on the value
of the passed-in direction flag there.

Anyway, remove this unused field from the ipa_cmd_info structure.
This is done as a separate patch to make it very obvious that it's
not required.

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

net: ipa: kill ipa_cmd_pipeline_clear()

Calling ipa_cmd_pipeline_clear() after stopping the channel
underlying the AP<-modem RX endpoint can lead to a deadlock.

This occurs in the ->runtime_suspend device power operation for the
IPA driver. While this callback is in progress, any other requests
for power will block until the callback returns.

Stopping the AP<-modem RX channel does not prevent the modem from
sending another packet to this endpoint. If a packet arrives for an
RX channel when the channel is stopped, an SUSPEND IPA interrupt
condition will be pending. Handling an IPA interrupt requires
power, so ipa_isr_thread() calls pm_runtime_get_sync() first thing.

The problem occurs because a "pipeline clear" command will not
complete while such a SUSPEND interrupt condition exists. So the
SUSPEND IPA interrupt handler won't proceed until it gets power;
that won't happen until the ->runtime_suspend callback (and its
"pipeline clear" command) completes; and that can't happen while
the SUSPEND interrupt condition exists.

It turns out that in this case there is no need to use the "pipeline
clear" command. There are scenarios in which clearing the pipeline
is required while suspending, but those are not (yet) supported
upstream. So a simple fix, avoiding the potential deadlock, is to
stop calling ipa_cmd_pipeline_clear() in ipa_endpoint_suspend().
This removes the only user of ipa_cmd_pipeline_clear(), so get rid
of that function. It can be restored again whenever it's needed.

This is basically a manual revert along with an explanation for
commit 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()").

Fixes: 6cb63ea6a39ea ("net: ipa: introduce ipa_cmd_tag_process()")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ipa: kill the remaining conditional validation code

There are only a few remaining spots that validate IPA code
conditional on whether a symbol is defined at compile time.
The checks are not expensive, so just build them always.

This completes the removal of all CONFIG_VALIDATE/CONFIG_VALIDATION
IPA code.

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

net: ipa: fix ipa_cmd_table_valid()

Stop supporting different sizes for hashed and non-hashed filter or
route tables. Add BUILD_BUG_ON() calls to verify the sizes of the
fields in the filter/route table initialization immediate command
are the same.

Add a check to ipa_cmd_table_valid() to ensure the size of the
memory region being checked fits within the immediate command field
that must hold it.

Remove two Boolean parameters used only for error reporting. This
actually fixes a bug that would only show up if IPA_VALIDATE were
defined. Define ipa_cmd_table_valid() unconditionally (no longer
dependent on IPA_VALIDATE).

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

net: ipa: fix all kernel-doc warnings

Fix all warnings produced when running:
scripts/kernel-doc -none drivers/net/ipa/*.[ch]

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

net: ipa: signal when tag transfer completes

There are times, such as when the modem crashes, when we issue
commands to clear the IPA hardware pipeline. These commands include
a data transfer command that delivers a small packet directly to the
default (AP<-LAN RX) endpoint.

The places that do this wait for the transactions that contain these
commands to complete, but the pipeline can't be assumed clear until
the sent packet has been *received*.

The small transfer will be delivered with a status structure, and
that status will indicate its tag is valid. This is the only place
we send a tagged packet, so we use the tag to determine when the
pipeline clear packet has arrived.

Add a completion to the IPA structure to to be used to signal
the receipt of a pipeline clear packet. Create a new function
ipa_cmd_pipeline_clear_wait() that will wait for that completion.

Reinitialize the completion whenever pipeline clear commands are
added to a transaction. Extend ipa_endpoint_status_tag() to check
whether a packet whose status contains a valid tag was sent from the
AP->command TX endpoint, and if so, signal the new IPA completion.

Have all callers of ipa_cmd_pipeline_clear_add() wait for the
pipeline clear indication after the transaction that clears the
pipeline has completed.

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

net: ipa: rename "tag status" symbols

There is a set of functions and symbols related to performing
"tag_process" immediate commands to clear the IPA pipeline. The
name is related to one of the commands issued when doing this, but
it doesn't really convey the overall purpose of taking this action.

The purpose is to take some steps to "clear out" the hardware
pipeline, and to wait until that process completes, to ensure the
IPA hardware is in a well-defined state.

Rename these symbols to use "pipeline_clear" in their names instead.
Add some comments to explain a bit more about what's going on.

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

net: ipa: define enumerated types consistently

Consistently define numeric values for enumerated type members using
hexidecimal (rather than decimal) format values. Align the values
assigned in the same column in each file.

Only assign values where they really matter, for example don't
assign IPA_ENDPOINT_AP_MODEM_TX the value 0.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ipa: fix kerneldoc comments

This commit affects comments (and in one case, whitespace) only.

Throughout the IPA code, return statements are documented using
"@Return:", whereas they should use "Return:" instead. Fix these
mistakes.

In function definitions, some parameters are missing their comment
to describe them. And in structure definitions, some fields are
missing their comment to describe them. Add these missing
descriptions.

Some arguments changed name and type along the way, but their
descriptions were not updated (an endpoint pointer is now used in
many places that previously used an endpoint ID). Fix these
incorrect parameter descriptions.

In the description for the ipa_clock structure, one field had a
semicolon instead of a colon in its description. Fix this.

Add a missing function description for ipa_gsi_endpoint_data_empty().

All of these issues were identified when building with "W=1".

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

net: ipa: introduce ipa_cmd_tag_process()

Create a new function ipa_cmd_tag_process() that simply allocates a
transaction, adds a tag process command to it to clear the hardware
pipeline, and commits the transaction.

Call it in from ipa_endpoint_suspend(), after suspending the modem
endpoints but before suspending the AP command TX and AP LAN RX
endpoints (which are used by the tag sequence).

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

net: ipa: kill ipa_cmd_dma_task_32b_addr_add()

A recent commit removed the only use of ipa_cmd_dma_task_32b_addr_add().
This function (and the IPA immediate command it implements) is no
longer needed, so get rid of it, along with all of the definitions
associated with it. Isolate its removal in a commit so it can be
easily added back again if needed.

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

soc: qcom: ipa: immediate commands

One TX endpoint (per EE) is used for issuing immediate commands to
the IPA. These commands request activites beyond simple data
transfers to be done by the IPA hardware. For example, the IPA is
able to manage routing packets among endpoints, and immediate commands
are used to configure tables used for that routing.

Immediate commands are built on top of GSI transactions. They are
different from normal transfers (in that they use a special endpoint,
and their "payload" is interpreted differently), so separate functions
are used to issue immediate command transactions.

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