kernel/linux.git/drivers/net/ipa/gsi.h, branch v5.19

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: support enhanced channel flow control

2021-11-26T04:04:52+00:00

IPA v4.2 introduced GSI channel flow control, used instead of IPA endpoint DELAY mode to prevent a TX channel from injecting packets into the IPA core. It used a new FLOW_CONTROLLED channel state which could be entered using GSI generic commands. IPA v4.11 extended the channel flow control model. Rather than having a distinct FLOW_CONTROLLED channel state, each channel has a "flow control" property that can be enabled or not--independent of the channel state. The AP (or modem) can modify this property using the same GSI generic commands as before. The AP only uses channel flow control on modem TX channels, and only when recovering from a modem crash. The AP has no way to discover the state of a modem channel, so the fact that (starting with IPA v4.11) flow control no longer uses a distinct channel state is invisible to the AP. So enhanced flow control generally does not change the way AP uses flow control. There are a few small differences, however: - There is a notion of "primary" or "secondary" flow control, and when enabling or disabling flow control that must be specified in a new field in the GSI generic command register. For now, we always specify 0 (meaning "primary"). - When disabling flow control, it's possible a request will need to be retried. We retry up to 5 times in this case. - Another new generic command allows the current flow control state to be queried. We do not use this. Other than the need for retries, the code essentially works the same way as before. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski

net: ipa: introduce channel flow control

2021-11-26T04:03:20+00:00

One quirk for certain versions of IPA is that endpoint DELAY mode does not work properly. IPA DELAY mode prevents any packets from being delivered to the IPA core for processing on a TX endpoint. The AP uses DELAY mode when the modem crashes, to prevent modem TX endpoints from generating traffic during crash recovery. Without this, there is a chance the hardware will stall during recovery from a modem crash. To achieve a similar effect, a GSI FLOW_CONTROLLED channel state was created. A STARTED TX channel can be placed in FLOW_CONTROLLED state, which prevents the transfer of any more packets. A channel in FLOW_CONTROLLED state can be either returned to STARTED state, or can be transitioned to STOPPED state. Because this operates on GSI channels, two generic commands were added to allow the AP to control this state for modem channels (similar to the ALLOCATE and HALT channel commands). Previously the code assumed this quirk only applied to IPA v4.2. In fact, channel flow control (rather than endpoint DELAY mode) should be used for all versions *starting* with IPA v4.2. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski

net: ipa: rearrange GSI structure fields

2021-11-26T03:37:34+00:00

The dummy net_device is a large field in the GSI structure, but it is not at all interesting from the perspective of debugging. Move it to the end of the GSI structure so the other fields are easier to find in memory. The channel and event ring arrays are also very large, so move them near the end of the structure as well. Swap the position of the result and completion fields to improve structure packing. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski

net: ipa: GSI only needs one completion

2021-11-26T03:37:34+00:00

A mutex ensures we never submit more than one GSI command of any kind at once. This means the per-channel and per-event ring completion structures provide no benefit. Instead, just use the single (existing) GSI completion to signal the completion of GSI commands of all types. This makes gsi_evt_ring_init() a trivial function with no inverse, so open-code it in its sole caller and get rid of the function. Signed-off-by: Alex Elder Signed-off-by: Jakub Kicinski

net: ipa: disable GSI interrupts while suspended

2021-08-04T09:12:05+00:00

Introduce new functions gsi_suspend() and gsi_resume(), which will disable the GSI interrupt handler after all endpoints are suspended and re-enable it before endpoints are resumed. This will ensure no GSI interrupt handler will fire when the hardware is suspended. Here's a little further explanation. There are seven GSI interrupt types, and most are disabled except when needed. - These two are not used (never enabled): GSI_INTER_EE_CH_CTRL GSI_INTER_EE_EV_CTRL - These two are only used to implement channel and event ring commands, and are only enabled while a command is underway: GSI_CH_CTRL GSI_EV_CTRL - The IEOB interrupt signals I/O completion. It will not fire when a channel is stopped (or "suspended"). GSI_IEOB - This interrupt is used to allocate or halt modem channels, and is only enabled while such a command is underway. GSI_GLOB_EE However it also is used to signal certain errors, and this could occur at any time. - The general interrupt signals general errors, and could occur at any time. GSI_GENERAL The purpose for this change is to ensure no global or general interrupts fire due to errors while the hardware is suspended. We enable the clock on resume, and at that time we can "handle" (at least report) these error conditions. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: use gsi->version for channel suspend/resume

2021-08-04T09:12:05+00:00

The GSI layer has the IPA version now, so there's no need for version-specific flags to be passed from IPA. One instance of this is in gsi_channel_suspend() and gsi_channel_resume(), which indicate whether or not the endpoint suspend is implemented by GSI stopping the channel. We can make that determination based on gsi->version, eliminating the need for a Boolean flag in those functions. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: introduce gsi_ring_setup()

2021-06-21T19:30:59+00:00

Prior to IPA v3.5.1, there is no HW_PARAM_2 GSI register, which we use to determine the number of channels and endpoints per execution environment. In that case, we will just assume the number supported is the maximum supported by the driver. Introduce gsi_ring_setup() to encapsulate the code that determines the number of channels and endpoints. Update GSI_EVT_RING_COUNT_MAX so it is big enough to handle any available channel for all supported hardware (IPA v4.9 can have 23 channels and 24 event rings). Signed-off-by: Alex Elder Acked-by: AngeloGioacchino Del Regno Signed-off-by: David S. Miller

net: ipa: increase channels and events

2021-03-24T23:52:47+00:00

Increase the maximum number of channels and event rings supported by the driver, to allow the maximum available on the SDX55. Signed-off-by: Alex Elder Signed-off-by: David S. Miller

net: ipa: use a separate pointer for adjusted GSI memory

2021-02-13T00:54:16+00:00

This patch actually fixes a bug, though it doesn't affect the two platforms supported currently. The fix implements GSI memory pointers a bit differently. For IPA version 4.5 and above, the address space for almost all GSI registers is adjusted downward by a fixed amount. This is currently handled by adjusting the I/O virtual address pointer after it has been mapped. The bug is that the pointer is not "de-adjusted" as it should be when it's unmapped. This patch fixes that error, but it does so by maintaining one "raw" pointer for the mapped memory range. This is assigned when the memory is mapped and used to unmap the memory. This pointer is also used to access the two registers that do *not* sit in the "adjusted" memory space. Rather than adjusting *that* pointer, we maintain a separate pointer that's an adjusted copy of the "raw" pointer, and that is used for most GSI register accesses. Signed-off-by: Alex Elder Signed-off-by: David S. Miller