linux-dev/drivers/net/ipa/ipa_cmd.c, branch linus/master

net: ipa: remove command info pool

2022-05-22T19:46:12Z

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 Signed-off-by: David S. Miller

net: ipa: remove command direction argument

2022-05-22T19:46:12Z

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 Signed-off-by: David S. Miller

net: ipa: kill gsi_trans_commit_wait_timeout()

2022-05-22T19:46:12Z

Since the beginning gsi_trans_commit_wait_timeout() has existed to provide a way to allow waiting a limited time for a transaction to complete. But that function has never been used. In fact, there is no use for this function, because a transaction committed to hardware should *always* complete. The only reason it might not complete is if there were a hardware failure, or perhaps a system configuration error. Furthermore, if a timeout ever did occur, the IPA hardware would be in an indeterminate state, from which there is no recovery. It would require some sort of complete IPA reset, and would require the participation of the modem, and at this time there is no such sequence defined. So get rid of the definition of gsi_trans_commit_wait_timeout(), and update a few comments accordingly. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: kill ipa_cmd_pipeline_clear()

2021-11-23T12:26:40Z

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 Signed-off-by: David S. Miller

net: ipa: use WARN_ON() rather than assertions

2021-07-26T21:38:11Z

I've added commented assertions to record certain properties that can be assumed to hold in certain places in the IPA code. Convert these into real WARN_ON() calls so the assertions are actually checked, using the standard WARN_ON() mechanism. Where errors can be returned, return an error if a warning is triggered. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: kill the remaining conditional validation code

2021-07-26T21:38:11Z

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 Signed-off-by: David S. Miller

net: ipa: fix ipa_cmd_table_valid()

2021-07-26T21:38:11Z

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 Signed-off-by: David S. Miller

net: ipa: introduce ipa_mem_find()

2021-06-10T21:50:08Z

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 Signed-off-by: David S. Miller

net: ipa: clean up header memory validation

2021-06-10T21:50:08Z

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 Signed-off-by: David S. Miller

net: ipa: kill IPA_TABLE_ENTRY_SIZE

2021-03-29T01:12:03Z

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 Signed-off-by: David S. Miller