can: dev: can_get_state_str(): Remove dead code

The default switch case ends with a return; meaning this return is
never reached.

Coverity-ID: 1497123
Signed-off-by: Ariel Otilibili <ariel.otilibil

can: dev: can_get_state_str(): Remove dead code

The default switch case ends with a return; meaning this return is
never reached.

Coverity-ID: 1497123
Signed-off-by: Ariel Otilibili <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: can_set_termination(): allow sleeping GPIOs

In commit 6e86a1543c37 ("can: dev: provide optional GPIO based
termination support") GPIO based termination support was added.

For no particula

can: dev: can_set_termination(): allow sleeping GPIOs

In commit 6e86a1543c37 ("can: dev: provide optional GPIO based
termination support") GPIO based termination support was added.

For no particular reason that patch uses gpiod_set_value() to set the
GPIO. This leads to the following warning, if the systems uses a
sleeping GPIO, i.e. behind an I2C port expander:

| WARNING: CPU: 0 PID: 379 at /drivers/gpio/gpiolib.c:3496 gpiod_set_value+0x50/0x6c
| CPU: 0 UID: 0 PID: 379 Comm: ip Not tainted 6.11.0-20241016-1 #1 823affae360cc91126e4d316d7a614a8bf86236c

Replace gpiod_set_value() by gpiod_set_value_cansleep() to allow the
use of sleeping GPIOs.

Cc: Nicolai Buchwitz <[email protected]>
Cc: Lino Sanfilippo <[email protected]>
Cc: [email protected]
Reported-by: Leonard Göhrs <[email protected]>
Tested-by: Leonard Göhrs <[email protected]>
Fixes: 6e86a1543c37 ("can: dev: provide optional GPIO based termination support")
Link: https://patch.msgid.link/20241121-dev-fix-can_set_termination-v1-1-41fa6e29216d@pengutronix.de
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: Remove setting of RX software timestamp

The responsibility for reporting of RX software timestamp has moved to
the core layer (see __ethtool_get_ts_info()), remove usage from the
device dr

can: dev: Remove setting of RX software timestamp

The responsibility for reporting of RX software timestamp has moved to
the core layer (see __ethtool_get_ts_info()), remove usage from the
device drivers.

Reviewed-by: Carolina Jubran <[email protected]>
Reviewed-by: Rahul Rameshbabu <[email protected]>
Signed-off-by: Gal Pressman <[email protected]>
Reviewed-by: Marc Kleine-Budde <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: Add struct kernel_ethtool_ts_info

In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_

net: Add struct kernel_ethtool_ts_info

In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.

Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.

Acked-by: Shannon Nelson <[email protected]>
Acked-by: Alexandra Winter <[email protected]>
Signed-off-by: Kory Maincent <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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net: annotate writes on dev->mtu from ndo_change_mtu()

Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c94510 ("inet: p

net: annotate writes on dev->mtu from ndo_change_mtu()

Simon reported that ndo_change_mtu() methods were never
updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted
in commit 501a90c94510 ("inet: protect against too small
mtu values.")

We read dev->mtu without holding RTNL in many places,
with READ_ONCE() annotations.

It is time to take care of ndo_change_mtu() methods
to use corresponding WRITE_ONCE()

Signed-off-by: Eric Dumazet <[email protected]>
Reported-by: Simon Horman <[email protected]>
Closes: https://lore.kernel.org/netdev/[email protected]/
Reviewed-by: Jacob Keller <[email protected]>
Reviewed-by: Sabrina Dubroca <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Acked-by: Shannon Nelson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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can: dev: add can_state_get_by_berr_counter() to return the CAN state based on the current error counters

Some CAN controllers do not have a register that contains the current
CAN state, but only a

can: dev: add can_state_get_by_berr_counter() to return the CAN state based on the current error counters

Some CAN controllers do not have a register that contains the current
CAN state, but only a register that contains the error counters.

Introduce a new function can_state_get_by_berr_counter() that returns
the current TX and RX state depending on the provided CAN bit error
counters.

Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: can_restart(): move debug message and stats after successful restart

Move the debug message "restarted" and the CAN restart stats_after_
the successful restart of the CAN device, because t

can: dev: can_restart(): move debug message and stats after successful restart

Move the debug message "restarted" and the CAN restart stats_after_
the successful restart of the CAN device, because the restart may
fail.

While there update the error message from printing the error number to
printing symbolic error names.

Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-4-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <[email protected]>
[mkl: mention stats in subject and description, too]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: can_restart(): reverse logic to remove need for goto

Reverse the logic in the if statement and eliminate the need for a
goto to simplify code readability.

Link: https://lore.kernel.org/al

can: dev: can_restart(): reverse logic to remove need for goto

Reverse the logic in the if statement and eliminate the need for a
goto to simplify code readability.

Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-3-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: can_restart(): fix race condition between controller restart and netif_carrier_on()

This race condition was discovered while updating the at91_can driver
to use can_bus_off(). The followin

can: dev: can_restart(): fix race condition between controller restart and netif_carrier_on()

This race condition was discovered while updating the at91_can driver
to use can_bus_off(). The following scenario describes how the
converted at91_can driver would behave.

When a CAN device goes into BUS-OFF state, the driver usually
stops/resets the CAN device and calls can_bus_off().

This function sets the netif carrier to off, and (if configured by
user space) schedules a delayed work that calls can_restart() to
restart the CAN device.

The can_restart() function first checks if the carrier is off and
triggers an error message if the carrier is OK.

Then it calls the driver's do_set_mode() function to restart the
device, then it sets the netif carrier to on. There is a race window
between these two calls.

The at91 CAN controller (observed on the sama5d3, a single core 32 bit
ARM CPU) has a hardware limitation. If the device goes into bus-off
while sending a CAN frame, there is no way to abort the sending of
this frame. After the controller is enabled again, another attempt is
made to send it.

If the bus is still faulty, the device immediately goes back to the
bus-off state. The driver calls can_bus_off(), the netif carrier is
switched off and another can_restart is scheduled. This occurs within
the race window before the original can_restart() handler marks the
netif carrier as OK. This would cause the 2nd can_restart() to be
called with an OK netif carrier, resulting in an error message.

The flow of the 1st can_restart() looks like this:

can_restart()
// bail out if netif_carrier is OK

netif_carrier_ok(dev)
priv->do_set_mode(dev, CAN_MODE_START)
// enable CAN controller
// sama5d3 restarts sending old message

// CAN devices goes into BUS_OFF, triggers IRQ

// IRQ handler start
at91_irq()
at91_irq_err_line()
can_bus_off()
netif_carrier_off()
schedule_delayed_work()
// IRQ handler end

netif_carrier_on()

The 2nd can_restart() will be called with an OK netif carrier and the
error message will be printed.

To close the race window, first set the netif carrier to on, then
restart the controller. In case the restart fails with an error code,
roll back the netif carrier to off.

Fixes: 39549eef3587 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-2-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: can_restart(): don't crash kernel if carrier is OK

During testing, I triggered a can_restart() with the netif carrier
being OK [1]. The BUG_ON, which checks if the carrier is OK, results
i

can: dev: can_restart(): don't crash kernel if carrier is OK

During testing, I triggered a can_restart() with the netif carrier
being OK [1]. The BUG_ON, which checks if the carrier is OK, results
in a fatal kernel crash. This is neither helpful for debugging nor for
a production system.

[1] The root cause is a race condition in can_restart() which will be
fixed in the next patch.

Do not crash the kernel, issue an error message instead, and continue
restarting the CAN device anyway.

Fixes: 39549eef3587 ("can: CAN Network device driver and Netlink interface")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-1-91b5c1fd922c@pengutronix.de
Reviewed-by: Vincent Mailhol <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: register_candev(): bail out if both fixed bit rates and bit timing constants are provided

The CAN driver framework supports either fixed bit rates or bit timing
constants. Bail out during

can: dev: register_candev(): bail out if both fixed bit rates and bit timing constants are provided

The CAN driver framework supports either fixed bit rates or bit timing
constants. Bail out during driver registration if both are given.

Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: register_candev(): ensure that bittiming const are valid

Implement the function can_bittiming_const_valid() to check the
validity of the specified bit timing constant. Call this function f

can: dev: register_candev(): ensure that bittiming const are valid

Implement the function can_bittiming_const_valid() to check the
validity of the specified bit timing constant. Call this function from
register_candev() to check the bit timing constants during the
registration of the CAN interface.

Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: add generic function can_eth_ioctl_hwts()

Tools based on libpcap (such as tcpdump) expect the SIOCSHWTSTAMP
ioctl call to be supported. This is also specified in the kernel doc
[1]. The pu

can: dev: add generic function can_eth_ioctl_hwts()

Tools based on libpcap (such as tcpdump) expect the SIOCSHWTSTAMP
ioctl call to be supported. This is also specified in the kernel doc
[1]. The purpose of this ioctl is to toggle the hardware timestamps.

Currently, CAN devices which support hardware timestamping have those
always activated. can_eth_ioctl_hwts() is a dumb function that will
always succeed when requested to set tx_type to HWTSTAMP_TX_ON or
rx_filter to HWTSTAMP_FILTER_ALL.

[1] Kernel doc: Timestamping, section 3.1 "Hardware Timestamping
Implementation: Device Drivers"
Link: https://docs.kernel.org/networking/timestamping.html#hardware-timestamping-implementation-device-drivers

Signed-off-by: Vincent Mailhol <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: add generic function can_ethtool_op_get_ts_info_hwts()

Add function can_ethtool_op_get_ts_info_hwts(). This function will be
used by CAN devices with hardware TX/RX timestamping support to

can: dev: add generic function can_ethtool_op_get_ts_info_hwts()

Add function can_ethtool_op_get_ts_info_hwts(). This function will be
used by CAN devices with hardware TX/RX timestamping support to
implement ethtool_ops::get_ts_info. This function does not offer
support to activate/deactivate hardware timestamps at device level nor
support the filter options (which is currently the case for all CAN
devices with hardware timestamping support).

The fact that hardware timestamp can not be deactivated at hardware
level does not impact the userland. As long as the user do not set
SO_TIMESTAMPING using a setsockopt() or ioctl(), the kernel will not
emit TX timestamps (RX timestamps will still be reproted as it is the
case currently).

Drivers which need more fine grained control remains free to implement
their own function, but we foresee that the generic function
introduced here will be sufficient for the majority.

Signed-off-by: Vincent Mailhol <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: Kconfig: turn menu "CAN Device Drivers" into a menuconfig using CAN_DEV

In the next patches, the software/virtual drivers (slcan, v(x)can)
will depend on drivers/net/can/dev/skb.o.

This patch

can: Kconfig: turn menu "CAN Device Drivers" into a menuconfig using CAN_DEV

In the next patches, the software/virtual drivers (slcan, v(x)can)
will depend on drivers/net/can/dev/skb.o.

This patch changes the scope of the can-dev module to include the
above mentioned drivers.

To do so, we reuse the menu "CAN Device Drivers" and turn it into a
configmenu using the config symbol CAN_DEV (which we released in
previous patch). Also, add a description to this new CAN_DEV
menuconfig.

The symbol CAN_DEV now only triggers the build of skb.o. For this
reasons, all the macros from linux/module.h are deported from
drivers/net/can/dev/dev.c to drivers/net/can/dev/skb.c.

Finally, drivers/net/can/dev/Makefile is adjusted accordingly.

Link: https://lore.kernel.org/all/[email protected]
Suggested-by: Oliver Hartkopp <[email protected]>
Signed-off-by: Vincent Mailhol <[email protected]>
Acked-by: Max Staudt <[email protected]>
Tested-by: Oliver Hartkopp <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: can-dev: remove obsolete CAN LED support

Since commit 30f3b42147ba6f ("can: mark led trigger as broken") the
CAN specific LED support was disabled and marked as BROKEN. As the
common LED suppor

can: can-dev: remove obsolete CAN LED support

Since commit 30f3b42147ba6f ("can: mark led trigger as broken") the
CAN specific LED support was disabled and marked as BROKEN. As the
common LED support with CONFIG_LEDS_TRIGGER_NETDEV should do this work
now the code can be removed as preparation for a CAN netdevice Kconfig
rework.

Link: https://lore.kernel.org/all/[email protected]
Suggested-by: Vincent Mailhol <[email protected]>
Signed-off-by: Oliver Hartkopp <[email protected]>
[mkl: remove led.h from MAINTAINERS]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: Use netif_rx().

Since commit
baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.")

the function netif_rx() can be used in preemptible/thread context as
well as in

can: Use netif_rx().

Since commit
baebdf48c3600 ("net: dev: Makes sure netif_rx() can be invoked in any context.")

the function netif_rx() can be used in preemptible/thread context as
well as in interrupt context.

Use netif_rx().

Cc: Marc Kleine-Budde <[email protected]>
Cc: Oliver Hartkopp <[email protected]>
Cc: Wolfgang Grandegger <[email protected]>
Cc: [email protected]
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Acked-by: Oliver Hartkopp <[email protected]>
Acked-by: Marc Kleine-Budde <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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can: dev: replace can_priv::ctrlmode_static by can_get_static_ctrlmode()

The statically enabled features of a CAN controller can be retrieved
using below formula:

| u32 ctrlmode_static = priv->ctrl

can: dev: replace can_priv::ctrlmode_static by can_get_static_ctrlmode()

The statically enabled features of a CAN controller can be retrieved
using below formula:

| u32 ctrlmode_static = priv->ctrlmode & ~priv->ctrlmode_supported;

As such, there is no need to store this information. This patch remove
the field ctrlmode_static of struct can_priv and provides, in
replacement, the inline function can_get_static_ctrlmode() which
returns the same value.

Link: https://lore.kernel.org/all/[email protected]
Signed-off-by: Vincent Mailhol <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: do not increase rx statistics when generating a CAN rx error message frame

The CAN error message frames (i.e. error skb) are an interface
specific to socket CAN. The payload of the CAN error me

can: do not increase rx statistics when generating a CAN rx error message frame

The CAN error message frames (i.e. error skb) are an interface
specific to socket CAN. The payload of the CAN error message frames
does not correspond to any actual data sent on the wire. Only an error
flag and a delimiter are transmitted when an error occurs (c.f. ISO
11898-1 section 10.4.4.2 "Error flag").

For this reason, it makes no sense to increment the rx_packets and
rx_bytes fields of struct net_device_stats because no actual payload
were transmitted on the wire.

This patch fixes all the CAN drivers.

Link: https://lore.kernel.org/all/[email protected]
CC: Marc Kleine-Budde <[email protected]>
CC: Nicolas Ferre <[email protected]>
CC: Alexandre Belloni <[email protected]>
CC: Ludovic Desroches <[email protected]>
CC: Chandrasekar Ramakrishnan <[email protected]>
CC: Maxime Ripard <[email protected]>
CC: Chen-Yu Tsai <[email protected]>
CC: Jernej Skrabec <[email protected]>
CC: Appana Durga Kedareswara rao <[email protected]>
CC: Naga Sureshkumar Relli <[email protected]>
CC: Michal Simek <[email protected]>
CC: Stephane Grosjean <[email protected]>
Tested-by: Jimmy Assarsson <[email protected]> # kvaser
Signed-off-by: Vincent Mailhol <[email protected]>
Acked-by: Stefan Mätje <[email protected]> # esd_usb2
Tested-by: Stefan Mätje <[email protected]> # esd_usb2
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: provide optional GPIO based termination support

For CAN buses to work, a termination resistor has to be present at both
ends of the bus. This resistor is usually 120 Ohms, other values may

can: dev: provide optional GPIO based termination support

For CAN buses to work, a termination resistor has to be present at both
ends of the bus. This resistor is usually 120 Ohms, other values may be
required for special bus topologies.

This patch adds support for a generic GPIO based CAN termination. The
resistor value has to be specified via device tree, and it can only be
attached to or detached from the bus. By default the termination is not
active.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Oleksij Rempel <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

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net: introduce CAN specific pointer in the struct net_device

Since 20dd3850bcf8 ("can: Speed up CAN frame receiption by using
ml_priv") the CAN framework uses per device specific data in the AF_CAN

net: introduce CAN specific pointer in the struct net_device

Since 20dd3850bcf8 ("can: Speed up CAN frame receiption by using
ml_priv") the CAN framework uses per device specific data in the AF_CAN
protocol. For this purpose the struct net_device->ml_priv is used. Later
the ml_priv usage in CAN was extended for other users, one of them being
CAN_J1939.

Later in the kernel ml_priv was converted to an union, used by other
drivers. E.g. the tun driver started storing it's stats pointer.

Since tun devices can claim to be a CAN device, CAN specific protocols
will wrongly interpret this pointer, which will cause system crashes.
Mostly this issue is visible in the CAN_J1939 stack.

To fix this issue, we request a dedicated CAN pointer within the
net_device struct.

Reported-by: [email protected]
Fixes: 20dd3850bcf8 ("can: Speed up CAN frame receiption by using ml_priv")
Fixes: ffd956eef69b ("can: introduce CAN midlayer private and allocate it automatically")
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Fixes: 497a5757ce4e ("tun: switch to net core provided statistics counters")
Signed-off-by: Oleksij Rempel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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can: dev: export can_get_state_str() function

The can_get_state_str() function is also relevant to the drivers. Export the
symbol and make it visible in the can/dev.h header.

Link: https://lore.ker

can: dev: export can_get_state_str() function

The can_get_state_str() function is also relevant to the drivers. Export the
symbol and make it visible in the can/dev.h header.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vincent Mailhol <[email protected]>
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: move netlink related code into seperate file

This patch moves the netlink related code of the CAN device infrastructure into
a separate file.

Reviewed-by: Vincent Mailhol <mailhol.vincent

can: dev: move netlink related code into seperate file

This patch moves the netlink related code of the CAN device infrastructure into
a separate file.

Reviewed-by: Vincent Mailhol <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: move skb related into seperate file

This patch moves the skb related code of the CAN device infrastructure into a
separate file.

Reviewed-by: Vincent Mailhol <[email protected]>

can: dev: move skb related into seperate file

This patch moves the skb related code of the CAN device infrastructure into a
separate file.

Reviewed-by: Vincent Mailhol <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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can: dev: move length related code into seperate file

This patch moves all CAN frame length related code of the CAN device
infrastructure into a separate file.

Reviewed-by: Vincent Mailhol <mailhol

can: dev: move length related code into seperate file

This patch moves all CAN frame length related code of the CAN device
infrastructure into a separate file.

Reviewed-by: Vincent Mailhol <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

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