net: ipa: sort all includes

Establish the rule that header files are always included in sorted
(POSIX local) order. Standard and private headers are separated by
a blank line.

Similarly, sort all

net: ipa: sort all includes

Establish the rule that header files are always included in sorted
(POSIX local) order. Standard and private headers are separated by
a blank line.

Similarly, sort all forward-declarations for structures.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: ipa: more include file cleanup

All of the config data files and all of the register definition
files (plus a few others) use GSI_EE_AP, which is defined in
"ipa_version.h". Include that header

net: ipa: more include file cleanup

All of the config data files and all of the register definition
files (plus a few others) use GSI_EE_AP, which is defined in
"ipa_version.h". Include that header where it's needed.

All of the IPA register definition files include "../ipa.h", though
none of them need anything defined there. Similarly, all of the GSI
register definition files include "../gsi.h", but don't need anything
defined there. Remove these unnneded includes.

All of the configuration data files include "../gsi.h", though none
of them need anything defined there, so remove these includes.

Remove other includes of local header files that are not required.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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net: ipa: don't save the platform device

The IPA platform device is now only used as the structure containing
the IPA device structure. Replace the platform device pointer with
a pointer to the dev

net: ipa: don't save the platform device

The IPA platform device is now only used as the structure containing
the IPA device structure. Replace the platform device pointer with
a pointer to the device structure.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: kill ipa_power_modem_queue_wake()

All ipa_power_modem_queue_wake() does is call netif_wake_queue()
on the modem netdev. There is no need to wrap that call in a
trivial function (and certa

net: ipa: kill ipa_power_modem_queue_wake()

All ipa_power_modem_queue_wake() does is call netif_wake_queue()
on the modem netdev. There is no need to wrap that call in a
trivial function (and certainly not one defined in "ipa_power.c").

So get rid of ipa_power_modem_queue_wake(), and replace its one
caller with a direct call to netif_wake_queue(). Determine the
netdev pointer to use from the private TX endpoint's netdev pointer.

Signed-off-by: Alex Elder <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: ipa: kill ipa_power_modem_queue_active()

All ipa_power_modem_queue_active() does now is call netif_wake_queue().
Just call netif_wake_queue() in the two places it's needed, and get
rid of ipa_p

net: ipa: kill ipa_power_modem_queue_active()

All ipa_power_modem_queue_active() does now is call netif_wake_queue().
Just call netif_wake_queue() in the two places it's needed, and get
rid of ipa_power_modem_queue_active().

Signed-off-by: Alex Elder <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: ipa: kill ipa_power_modem_queue_stop()

All ipa_power_modem_queue_stop() does now is call netif_stop_queue().
Just call netif_stop_queue() in the one place it's needed, and get
rid of ipa_power_

net: ipa: kill ipa_power_modem_queue_stop()

All ipa_power_modem_queue_stop() does now is call netif_stop_queue().
Just call netif_stop_queue() in the one place it's needed, and get
rid of ipa_power_modem_queue_stop().

Signed-off-by: Alex Elder <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: ipa: begin simplifying TX queue stop

There are a number of flags used in the IPA driver to attempt to
manage race conditions that can occur between runtime resume and
netdev transmit. If we di

net: ipa: begin simplifying TX queue stop

There are a number of flags used in the IPA driver to attempt to
manage race conditions that can occur between runtime resume and
netdev transmit. If we disable TX before requesting power, we can
avoid these races entirely, simplifying things considerably.

This patch implements the main change, disabling transmit always in
the net_device->ndo_start_xmit() callback, then re-enabling it again
whenever we find power is active (or when we drop the skb).

The patches that follow will refactor the "old" code to the point
that most of it can be eliminated.

Signed-off-by: Alex Elder <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: ipa: stash modem TX and RX endpoints

Rather than repeatedly looking up the endpoints in the name map,
save the modem TX and RX endpoint pointers in the netdev private
area.

Signed-off-by: Alex

net: ipa: stash modem TX and RX endpoints

Rather than repeatedly looking up the endpoints in the name map,
save the modem TX and RX endpoint pointers in the netdev private
area.

Signed-off-by: Alex Elder <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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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: Ale

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: ipa: save a copy of endpoint default config

All elements of the default endpoint configuration are used in the
code when programming an endpoint for use. But none of the other
configuration da

net: ipa: save a copy of endpoint default config

All elements of the default endpoint configuration are used in the
code when programming an endpoint for use. But none of the other
configuration data is ever needed once things are initialized.

So rather than saving a pointer to *all* of the configuration data,
save a copy of only the endpoint configuration portion.

This will eventually allow endpoint configuration to be modifiable
at runtime. But even before that it means we won't keep a pointer
to configuration data after when no longer needed.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: rename a few endpoint config data types

Rename the just-moved data structure types to drop the "_data"
suffix, to make it more obvious they are no longer meant to be used
just as read-only

net: ipa: rename a few endpoint config data types

Rename the just-moved data structure types to drop the "_data"
suffix, to make it more obvious they are no longer meant to be used
just as read-only initialization data. Rename the fields and
variables of these types to use "config" instead of "data" in the
name. This is another small step meant to facilitate review.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: open-code ether_setup()

About half of the fields set by the call in ipa_modem_netdev_setup()
are overwritten after the call. Instead, just skip the call, and
open-code the (other) assignm

net: ipa: open-code ether_setup()

About half of the fields set by the call in ipa_modem_netdev_setup()
are overwritten after the call. Instead, just skip the call, and
open-code the (other) assignments it makes to the net_device
structure fields.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: kill ipa_modem_init()

A recent commit made disabling the SMP2P "setup ready" interrupt
unrelated to ipa_modem_stop(). Given that, it seems fitting to get
rid of ipa_modem_init() and ipa_m

net: ipa: kill ipa_modem_init()

A recent commit made disabling the SMP2P "setup ready" interrupt
unrelated to ipa_modem_stop(). Given that, it seems fitting to get
rid of ipa_modem_init() and ipa_modem_exit() (which are trivial
wrapper functions), and call ipa_smp2p_init() and ipa_smp2p_exit()
directly instead.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

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net: ipa: separate disabling setup from modem stop

The IPA setup_complete flag is set at the end of ipa_setup(), when
the setup phase of initialization has completed successfully. This
occurs as pa

net: ipa: separate disabling setup from modem stop

The IPA setup_complete flag is set at the end of ipa_setup(), when
the setup phase of initialization has completed successfully. This
occurs as part of driver probe processing, or (if "modem-init" is
specified in the DTS file) it is triggered by the "ipa-setup-ready"
SMP2P interrupt generated by the modem.

In the latter case, it's possible for driver shutdown (or remove) to
begin while setup processing is underway, and this can't be allowed.
The problem is that the setup_complete flag is not adequate to signal
that setup is underway.

If setup_complete is set, it will never be un-set, so that case is
not a problem. But if setup_complete is false, there's a chance
setup is underway.

Because setup is triggered by an interrupt on a "modem-init" system,
there is a simple way to ensure the value of setup_complete is safe
to read. The threaded handler--if it is executing--will complete as
part of a request to disable the "ipa-modem-ready" interrupt. This
means that ipa_setup() (which is called from the handler) will run
to completion if it was underway, or will never be called otherwise.

The request to disable the "ipa-setup-ready" interrupt is currently
made within ipa_modem_stop(). Instead, disable the interrupt
outside that function in the two places it's called. In the case of
ipa_remove(), this ensures the setup_complete flag is safe to read
before we read it.

Rename ipa_smp2p_disable() to be ipa_smp2p_irq_disable_setup(), to be
more specific about its effect.

Fixes: 530f9216a953 ("soc: qcom: ipa: AP/modem communications")
Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: rename "ipa_clock.c"

Finally, rename "ipa_clock.c" to be "ipa_power.c" and "ipa_clock.h"
to be "ipa_power.h".

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <

net: ipa: rename "ipa_clock.c"

Finally, rename "ipa_clock.c" to be "ipa_power.c" and "ipa_clock.h"
to be "ipa_power.h".

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: rename ipa_clock_* symbols

Rename a number of functions to clarify that there is no longer a
notion of an "IPA clock," but rather that the functions are more
generally related to IPA power

net: ipa: rename ipa_clock_* symbols

Rename a number of functions to clarify that there is no longer a
notion of an "IPA clock," but rather that the functions are more
generally related to IPA power management.

ipa_clock_enable() -> ipa_power_enable()
ipa_clock_disable() -> ipa_power_disable()
ipa_clock_rate() -> ipa_core_clock_rate()
ipa_clock_init() -> ipa_power_init()
ipa_clock_exit() -> ipa_power_exit()

Rename the ipa_clock structure to be ipa_power. Rename all
variables and fields using that structure type "power" rather
than "clock".

Rename the ipa_clock_data structure to be ipa_power_data, and more
broadly, just substitute "power" for "clock" in places that
previously represented things related to the "IPA clock".

Update comments throughout.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: use autosuspend

Use runtime power management autosuspend.

Up until this point, we only suspended the IPA hardware for system
suspend; now we'll suspend it aggressively using runtime power

net: ipa: use autosuspend

Use runtime power management autosuspend.

Up until this point, we only suspended the IPA hardware for system
suspend; now we'll suspend it aggressively using runtime power
management, setting the initial autosuspend delay to half a second
of inactivity.

Replace pm_runtime_put() calls with pm_runtime_put_autosuspend(),
call pm_runtime_mark_last_busy() before each of those. In places
where we're shutting things down, or decrementing power references
for errors, use pm_runtime_put_noidle() instead.

Finally, remove ipa_runtime_idle(), so the ->runtime_suspend
callback will occur if idle.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: don't use ipa_clock_get() in "ipa_modem.c"

When we open or close the modem network device we need to ensure the
hardware is powered. Replace the callers of ipa_clock_get() found
in ipa_op

net: ipa: don't use ipa_clock_get() in "ipa_modem.c"

When we open or close the modem network device we need to ensure the
hardware is powered. Replace the callers of ipa_clock_get() found
in ipa_open() and ipa_stop() with calls to pm_runtime_get_sync().
If an error is returned, simply return that error to the caller
(without any error or warning message). This could conceivably
occur if the function was called while the system was suspended,
but that really shouldn't happen. Replace corresponding calls to
ipa_clock_put() with pm_runtime_put() also.

If the modem crashes we also need to ensure the hardware is powered
to recover. If getting power returns an error there's not much we
can do, but at least report the error. (Ideally the remoteproc SSR
code would ensure the AP was not suspended when it sends the
notification, but that is not (yet) the case.)

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: fix TX queue race

Jakub Kicinski pointed out a race condition in ipa_start_xmit() in a
recently-accepted series of patches:
https://lore.kernel.org/netdev/20210812195035.2816276-1-elder@

net: ipa: fix TX queue race

Jakub Kicinski pointed out a race condition in ipa_start_xmit() in a
recently-accepted series of patches:
https://lore.kernel.org/netdev/[email protected]/
We are stopping the modem TX queue in that function if the power
state is not active. We restart the TX queue again once hardware
resume is complete.

TX path Power Management
------- ----------------
pm_runtime_get(); no power Start resume
Stop TX queue ...
pm_runtime_put() Resume complete
return NETDEV_TX_BUSY Start TX queue

pm_runtime_get()
Power present, transmit
pm_runtime_put() (auto-suspend)

The issue is that the power management (resume) activity and the
network transmit activity can occur concurrently, and there's a
chance the queue will be stopped *after* it has been started again.

TX path Power Management
------- ----------------
Resume underway
pm_runtime_get(); no power ...
Resume complete
Start TX queue
Stop TX queue <-- No more transmits after this
pm_runtime_put()
return NETDEV_TX_BUSY

We address this using a STARTED flag to indicate when the TX queue
has been started from the resume path, and a spinlock to make the
flag and queue updates happen atomically.

TX path Power Management
------- ----------------
Resume underway
pm_runtime_get(); no power Resume complete
start TX queue \
If STARTED flag is *not* set: > atomic
Stop TX queue set STARTED flag /
pm_runtime_put()
return NETDEV_TX_BUSY

A second flag is used to address a different race that involves
another path requesting power.

TX path Other path Power Management
------- ---------- ----------------
pm_runtime_get_sync() Resume
Start TX queue \ atomic
Set STARTED flag /
(do its thing)
pm_runtime_put()
(auto-suspend)
pm_runtime_get() Mark delayed resume
STARTED *is* set, so
do *not* stop TX queue <-- Queue should be stopped here
pm_runtime_put()
return NETDEV_TX_BUSY Suspend done, resume
Resume complete
pm_runtime_get()
Stop TX queue
(STARTED is *not* set) Start TX queue \ atomic
pm_runtime_put() Set STARTED flag /
return NETDEV_TX_BUSY

So a STOPPED flag is set in the transmit path when it has stopped
the TX queue, and this pair of operations is also protected by the
spinlock. The resume path only restarts the TX queue if the STOPPED
flag is set. This case isn't a major problem, but it avoids the
"non-trivial amount of useless work" done by the networking stack
when NETDEV_TX_BUSY is returned.

Fixes: 6b51f802d652b ("net: ipa: ensure hardware has power in ipa_start_xmit()")
Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: don't hold clock reference while netdev open

Currently a clock reference is taken whenever the ->ndo_open
callback for the modem netdev is called. That reference is dropped
when the devic

net: ipa: don't hold clock reference while netdev open

Currently a clock reference is taken whenever the ->ndo_open
callback for the modem netdev is called. That reference is dropped
when the device is closed, in ipa_stop().

We no longer need this, because ipa_start_xmit() now handles the
situation where the hardware power state is not active.

Drop the clock reference in ipa_open() when we're done, and take a
new reference in ipa_stop() before we begin closing the interface.

Finally (and unrelated, but trivial), change the return type of
ipa_start_xmit() to be netdev_tx_t instead of int.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: don't stop TX on suspend

Currently we stop the modem netdev transmit queue when suspending
the hardware. For system suspend this ensured we'd never attempt
to transmit while attempting to

net: ipa: don't stop TX on suspend

Currently we stop the modem netdev transmit queue when suspending
the hardware. For system suspend this ensured we'd never attempt
to transmit while attempting to suspend the modem endpoints.

For runtime suspend, the IPA hardware might get suspended while the
system is operating. In that case we want an attempt to transmit a
packet to cause the hardware to resume if necessary. But if we
disable the queue this cannot happen.

So stop disabling the queue on suspend. In case we end up disabling
it in ipa_start_xmit() (see the previous commit), we still arrange
to start the TX queue on resume.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: ensure hardware has power in ipa_start_xmit()

We need to ensure the hardware is powered when we transmit a packet.
But if it's not, we can't block to wait for it. So asynchronously
reques

net: ipa: ensure hardware has power in ipa_start_xmit()

We need to ensure the hardware is powered when we transmit a packet.
But if it's not, we can't block to wait for it. So asynchronously
request power in ipa_start_xmit(), and only proceed if the return
value indicates the power state is active.

If the hardware is not active, a runtime resume request will have
been initiated. In that case, stop the network stack from further
transmit attempts until the resume completes. Return NETDEV_TX_BUSY,
to retry sending the packet once the queue is restarted.

If the power request returns an error (other than -EINPROGRESS,
which just means a resume requested elsewhere isn't complete), just
drop the packet.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: re-enable transmit in PM WQ context

Create a new work structure in the modem private data, and use it to
re-enable the modem network device transmit queue when resuming.

This is needed by

net: ipa: re-enable transmit in PM WQ context

Create a new work structure in the modem private data, and use it to
re-enable the modem network device transmit queue when resuming.

This is needed by the next patch, which stops the TX queue if IPA
power isn't active when a transmit request arrives. Packets will
start arriving the instant the TX queue is enabled, but resuming
isn't complete until ipa_modem_resume() returns. This way we're
sure to be resumed before transmits are allowed again.

Cancel it before calling ipa_stop() in ipa_modem_stop() to ensure
the transmit queue restart completes before it gets stopped there.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: have ipa_clock_get() return a value

We currently assume no errors occur when enabling or disabling the
IPA core clock and interconnects. And although this commit exposes
errors that could

net: ipa: have ipa_clock_get() return a value

We currently assume no errors occur when enabling or disabling the
IPA core clock and interconnects. And although this commit exposes
errors that could occur, we generally assume this won't happen in
practice.

This commit changes ipa_clock_get() and ipa_clock_put() so each
returns a value. The values returned are meant to mimic what the
runtime power management functions return, so we can set up error
handling here before we make the switch. Have ipa_clock_get()
increment the reference count even if it returns an error, to match
the behavior of pm_runtime_get().

More details follow.

When taking a reference in ipa_clock_get(), return 0 for the first
reference, 1 for subsequent references, or a negative error code if
an error occurs. Note that if ipa_clock_get() returns an error, we
must not touch hardware; in some cases such errors now cause entire
blocks of code to be skipped.

When dropping a reference in ipa_clock_put(), we return 0 or an
error code. The error would come from ipa_clock_disable(), which
now returns what ipa_interconnect_disable() returns (either 0 or a
negative error code). For now, callers ignore the return value;
if an error occurs, a message will have already been logged, and
little more can actually be done to improve the situation.

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: ipa: reorder netdev pointer assignments

Assign the ipa->modem_netdev and endpoint->netdev pointers *before*
registering the network device. As soon as the device is
registered it can be opened

net: ipa: reorder netdev pointer assignments

Assign the ipa->modem_netdev and endpoint->netdev pointers *before*
registering the network device. As soon as the device is
registered it can be opened, and by that time we'll want those
pointers valid.

Similarly, don't make those pointers NULL until *after* the modem
network device is unregistered in ipa_modem_stop().

Signed-off-by: Alex Elder <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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