kernel/linux.git/drivers/net/ipa/ipa_cmd.c, branch v6.1.168

net: ipa: update copyrights

2022-10-03T23:49:20+00:00

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

net: ipa: update comments

2022-10-03T23:49:05+00:00

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

net: ipa: introduce ipa_reg()

2022-09-28T01:42:50+00:00

Create a new function that returns a register descriptor given its ID. Change ipa_reg_offset() and ipa_reg_n_offset() so they take a register descriptor argument rather than an IPA pointer and register ID. Have them accept null pointers (and return an invalid 0 offset), to avoid the need for excessive error checking. (A warning is issued whenever ipa_reg() returns 0). Call ipa_reg() or ipa_reg_n() to look up information about the register before calls to ipa_reg_offset() and ipa_reg_n_offset(). Delay looking up offsets until they're needed to read or write registers. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski

net: ipa: use IPA register IDs to determine offsets

2022-09-28T01:42:49+00:00

Expose two inline functions that return the offset for a register whose ID is provided; one of them takes an additional argument that's used for registers that are parameterized. These both use a common helper function __ipa_reg_offset(), which just uses the offset symbols already defined. Replace all references to the offset macros defined for IPA registers with calls to ipa_reg_offset() or ipa_reg_n_offset(). Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski

net: ipa: rename channel->tlv_count

2022-06-13T11:01:58+00:00

Each GSI channel has a TLV FIFO of a certain size, specified in the configuration data for an AP channel. That size dictates the maximum number of TREs that are allowed in a single transaction. The only way that value is used after initialization is as a limit on the number of TREs in a transaction; calling it "tlv_count" isn't helpful, and in fact gsi_channel_trans_tre_max() exists to sort of abstract it. Instead, rename the channel->tlv_count field trans_tre_max, and get rid of the helper function. Update a couple of comments as well. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: remove command info pool

2022-05-22T19:46:12+00:00

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

2022-05-22T19:46:12+00:00

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()

2022-05-22T19:46:12+00:00

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()

2021-11-23T12:26:40+00:00

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

2021-07-26T21:38:11+00:00

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