net: wwan: make debugfs optional

Debugfs interface is optional for the regular modem use. Some distros
and users will want to disable this feature for security or kernel
size reasons. So add a configuration option that allows to completely
disable the debugfs interface of the WWAN devices.

A primary considered use case for this option was embedded firmwares.
For example, in OpenWrt, you can not completely disable debugfs, as a
lot of wireless stuff can only be configured and monitored with the
debugfs knobs. At the same time, reducing the size of a kernel and
modules is an essential task in the world of embedded software.
Disabling the WWAN and IOSM debugfs interfaces allows us to save 50K
(x86-64 build) of space for module storage. Not much, but already
considerable when you only have 16MB of storage.

So it is hard to just disable whole debugfs. Users need some fine
grained set of options to control which debugfs interface is important
and should be available and which is not.

The new configuration symbol is enabled by default and is hidden under
the EXPERT option. So a regular user would not be bothered by another
one configuration question. While an embedded distro maintainer will be
able to a little more reduce the final image size.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Acked-by: M Chetan Kumar <m.chetan.kumar@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: wwan: iosm: move debugfs knobs into a subdir

The modem traces collection is a device (and so driver) specific option.
Therefore, move the related debugfs files into a driver-specific
subdirectory under the common per WWAN device directory.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Acked-by: M Chetan Kumar <m.chetan.kumar@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: wwan: iosm: device trace collection using relayfs

This patch brings in support for device trace collection.
It implements relayfs interface for pushing device trace
from kernel space to user space.

Driver gets the debugfs base directory associated to WWAN
Device and creates trace_control and trace debugfs for
device tracing. Both trace_control & trace debugfs are
created under /sys/kernel/debug/wwan/wwan0/.

In order to collect device trace on trace0 interface, user
need to write 1 to trace_ctl interface.

Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: iosm: fw flashing & cd collection infrastructure changes

IOSM Makefile & WWAN Kconfig changes to support fw flashing & cd
collection module compliation.

Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert "net: wwan: iosm: firmware flashing and coredump collection"

The devlink parameters are not the right mechanism to pass
extra parameters to device flashing. The params added are
also undocumented.

This reverts commit 13bb8429ca98 ("net: wwan: iosm: firmware
flashing and coredump collection").

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: iosm: firmware flashing and coredump collection

This patch brings-in support for M.2 7560 Device firmware flashing &
coredump collection using devlink.
- Driver Registers with Devlink framework.
- Register devlink params callback for configuring device params
required in flashing or coredump flow.
- Implements devlink ops flash_update callback that programs modem
firmware.
- Creates region & snapshot required for device coredump log collection.

On early detection of device in boot rom stage. Driver registers with
Devlink framework and establish transport channel for PSI (Primary Signed
Image) injection. Once PSI is injected to device, the device execution
stage details are read to determine whether device is in flash or
exception mode. The collected information is reported to devlink user
space application & based on this informationi, application proceeds with
either modem firmware flashing or coredump collection.

Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: wwan: iosm: Remove DEBUG flag

Author forgot to remove that flag.

Fixes: f7af616c632e ("net: iosm: infrastructure")
Reported-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: iosm: infrastructure

1) Kconfig & Makefile changes for IOSM Driver compilation.
2) Add IOSM Driver documentation.
3) Modified MAINTAINER file for IOSM Driver addition.

Signed-off-by: M Chetan Kumar <m.chetan.kumar@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>