linux/drivers/net/ipa/ipa_cmd.c, branch v5.17

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

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-03-25T22:31:22Z

Signed-off-by: David S. Miller

net: ipa: reduce IPA version assumptions

2021-03-24T23:52:47Z

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 Signed-off-by: David S. Miller

net: ipa: fix init header command validation

2021-03-21T01:53:41Z

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 Signed-off-by: David S. Miller