Commit b360a13d44 ("can: dev: print bitrate error with two decimal
digits") changed calculation of the bit rate error from on-tenth of a
percent to on-hundredth of a percent, but forgot to adjust the scale of the
CAN_CALC_MAX_ERROR constant.
Keeping the existing logic unchanged: Only when the bitrate error exceeds
5% should an error be returned. Otherwise, simply output a warning log.
Fixes: b360a13d44 ("can: dev: print bitrate error with two decimal digits")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://patch.msgid.link/20260306-can-fix-v1-1-ac526cec6777@nxp.com
Cc: stable@kernel.org
[mkl: improve commit message]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
When routing CAN frames over different CAN interfaces the interface index
skb->iif is overwritten with every single hop. To prevent sending a CAN
frame back to its originating (first) incoming CAN interface another
ifindex variable is needed, which was stored in can_skb_priv::ifindex.
Move the can_skb_priv::ifindex content to can_skb_ext::can_iif.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260201-can_skb_ext-v8-3-3635d790fe8b@hartkopp.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
To remove the private CAN bus skb headroom infrastructure 8 bytes need to
be stored in the skb. The skb extensions are a common pattern and an easy
and efficient way to hold private data travelling along with the skb. We
only need the skb_ext_add() and skb_ext_find() functions to allocate and
access CAN specific content as the skb helpers to copy/clone/free skbs
automatically take care of skb extensions and their final removal.
This patch introduces the complete CAN skb extensions infrastructure:
- add struct can_skb_ext in new file include/net/can.h
- add include/net/can.h in MAINTAINERS
- add SKB_EXT_CAN to skbuff.c and skbuff.h
- select SKB_EXTENSIONS in Kconfig when CONFIG_CAN is enabled
- check for existing CAN skb extensions in can_rcv() in af_can.c
- add CAN skb extensions allocation at every skb_alloc() location
- duplicate the skb extensions if cloning outgoing skbs (framelen/gw_hops)
- introduce can_skb_ext_add() and can_skb_ext_find() helpers
The patch also corrects an indention issue in the original code from 2018:
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602010426.PnGrYAk3-lkp@intel.com/
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260201-can_skb_ext-v8-2-3635d790fe8b@hartkopp.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The can_skb_priv::skbcnt variable is used to identify CAN skbs in the RX
path analogue to the skb->hash.
As the skb hash is not filled in CAN skbs move the private skbcnt value to
skb->hash and set skb->sw_hash accordingly. The skb->hash is a value used
for RPS to identify skbs. Use it as intended.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260201-can_skb_ext-v8-1-3635d790fe8b@hartkopp.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The idea behind series 6c1f5146b2 ("Merge patch series "can: raw: better
approach to instantly reject unsupported CAN frames"") is to set the
capabilities of a CAN device (CAN-CC, CAN-FD, CAN-XL, and listen only) [1]
and, based on these capabilities, reject unsupported CAN frames in the
CAN-RAW protocol [2].
This works perfectly for CAN devices configured in CAN-FD or CAN-XL mode.
CAN devices with static CAN control modes define their capabilities via
can_set_static_ctrlmode() -> can_set_cap_info(). CAN devices configured by
the user space for CAN-FD or CAN-XL set their capabilities via
can_changelink() -> can_ctrlmode_changelink() -> can_set_cap_info().
However, in commit 166e87329c ("can: propagate CAN device capabilities
via ml_priv"), the capabilities of CAN devices are not initialized.
This results in CAN-RAW rejecting all CAN frames on devices directly
after ifup if the user space has not changed the CAN control mode.
Fix this problem by setting the default capabilities to CAN-CC in
alloc_candev_mqs() as soon as the CAN specific ml_priv is allocated.
[1] commit 166e87329c ("can: propagate CAN device capabilities via ml_priv")
[2] commit faba5860fc ("can: raw: instantly reject disabled CAN frames")
Fixes: 166e87329c ("can: propagate CAN device capabilities via ml_priv")
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260116-can_add_missing_set_caps-v1-1-7525126d8b20@pengutronix.de
[mkl: fix typo in subject]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Commit 1a620a7238 ("can: raw: instantly reject unsupported CAN frames")
caused a sequence of dependency and linker fixes.
Instead of accessing CAN device internal data structures which caused the
dependency problems this patch introduces capability information into the
CAN specific ml_priv data which is accessible from both sides.
With this change the CAN network layer can check the required features and
the decoupling of the driver layer and network layer is restored.
Fixes: 1a620a7238 ("can: raw: instantly reject unsupported CAN frames")
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260109144135.8495-3-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This reverts commit 1a620a7238
and its follow-up fixes for the introduced dependency issues.
commit 1a620a7238 ("can: raw: instantly reject unsupported CAN frames")
commit cb2dc6d286 ("can: Kconfig: select CAN driver infrastructure by default")
commit 6abd4577bc ("can: fix build dependency")
commit 5a5aff6338 ("can: fix build dependency")
The entire problem was caused by the requirement that a new network layer
feature needed to know about the protocol capabilities of the CAN devices.
Instead of accessing CAN device internal data structures which caused the
dependency problems a better approach has been developed which makes use of
CAN specific ml_priv data which is accessible from both sides.
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260109144135.8495-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
A recent bugfix introduced a new problem with Kconfig dependencies:
WARNING: unmet direct dependencies detected for CAN_DEV
Depends on [n]: NETDEVICES [=n] && CAN [=m]
Selected by [m]:
- CAN [=m] && NET [=y]
Since the CAN core code now links into the CAN device code, that
particular function needs to be available, though the rest of it
does not.
Revert the incomplete fix and instead use Makefile logic to avoid
the link failure.
Fixes: cb2dc6d286 ("can: Kconfig: select CAN driver infrastructure by default")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202512091523.zty3CLmc-lkp@intel.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251204100015.1033688-1-arnd@kernel.org
[mkl: removed module option from CAN_DEV help text (thanks Vincent)]
[mkl: removed '&& CAN' from Kconfig dependency (thanks Vincent)]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The optimum sample point value depends on the bit symmetry. The more
asymmetric the bit is, the more the sample point would be located
towards the end of the bit. On the contrary, if the transceiver only
has a small asymmetry, the optimal sample point would be slightly
after the centre of the bit.
For NRZ encoding (used by Classical CAN, CAN FD and CAN XL with TMS
off), the optimum sample points values are above 70% as implemented in
can_calc_sample_point_nrz().
When TMS is on, CAN XL optimum sample points are near to 50% or
60% [1]. Add can_calc_sample_point_pwm() which returns a sample point
which is suitable for PWM encoding. We crafted the formula to make it
return the same values as below table (source: table 3 of [1]).
Bit rate (Mbits/s) Sample point
-------------------------------------
2.0 51.3%
5.0 53.1%
8.0 55.0%
10.0 56.3%
12.3 53.8%
13.3 58.3%
14.5 54.5%
16.0 60.0%
17.7 55.6%
20.0 62.5%
The calculation simply consists of setting a slightly too high sample
point and then letting can_update_sample_point() correct the values.
For now, it is just a formula up our sleeves which matches the
empirical observations of [1]. Once CiA recommendations become
available, can_calc_sample_point_pwm() should be updated accordingly.
[1] CAN XL system design: Clock tolerances and edge deviations edge
deviations
Link: https://www.can-cia.org/fileadmin/cia/documents/publications/cnlm/december_2024/cnlm_24-4_p18_can_xl_system_design_clock_tolerances_and_edge_deviations_dr_arthur_mutter_bosch.pdf
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-14-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
CAN XL optimal sample point for PWM encoding (when TMS is on) differs
from the NRZ optimal one. There is thus a need to calculate a
different sample point depending whether TMS is on or off.
This is a preparation change: move the sample point calculation from
can_calc_bittiming() into the new can_calc_sample_point_nrz()
function.
In an upcoming change, a function will be added to calculate the
sample point for PWM encoding.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-13-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The functions can_update_sample_point() and can_calc_bittiming() are
generic and meant to be used for both the nominal and the data bittiming
calculation.
However, those functions use misleading terminologies such as "bitrate
nominal" or "sample point nominal". Replace all places where the word
"nominal" appears with "reference" in order to better distinguish it from
the calculated values.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-12-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
When the TMS is switched on, the node uses PWM (Pulse Width
Modulation) during the data phase instead of the classic NRZ (Non
Return to Zero) encoding.
PWM is configured by three parameters:
- PWMS: Pulse Width Modulation Short phase
- PWML: Pulse Width Modulation Long phase
- PWMO: Pulse Width Modulation Offset time
For each of these parameters, define three IFLA symbols:
- IFLA_CAN_PWM_PWM*_MIN: the minimum allowed value.
- IFLA_CAN_PWM_PWM*_MAX: the maximum allowed value.
- IFLA_CAN_PWM_PWM*: the runtime value.
This results in a total of nine IFLA symbols which are all nested in a
parent IFLA_CAN_XL_PWM symbol.
IFLA_CAN_PWM_PWM*_MIN and IFLA_CAN_PWM_PWM*_MAX define the range of
allowed values and will match the value statically configured by the
device in struct can_pwm_const.
IFLA_CAN_PWM_PWM* match the runtime values stored in struct can_pwm.
Those parameters may only be configured when the tms mode is on. If
the PWMS, PWML and PWMO parameters are provided, check that all the
needed parameters are present using can_validate_pwm(), then check
their value using can_validate_pwm_bittiming(). PWMO defaults to zero
if omitted. Otherwise, if CAN_CTRLMODE_XL_TMS is true but none of the
PWM parameters are provided, calculate them using can_calc_pwm().
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-11-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Perform the PWM calculation according to CiA recommendations.
Note that for databitrates greater than 5 MBPS, tqmin is less than
CAN_PWM_NS_MAX (which is defined to 200 nano seconds), consequently,
the result of the division:
DIV_ROUND_UP(xl_ns, CAN_PWM_NS_MAX)
is one and thus the for loop automatically stops on the first
iteration giving a single PWM symbol per bit as expected. Because of
that, there is no actual need for a separate conditional branch for
when the databitrate is greater than 5 MBPS.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-10-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Add can_validate_pwm() to validate the values pwms, pwml and pwml.
Error messages are added to each of the checks to inform the user on
what went wrong. Refer to those error messages to understand the
validation logic.
The boundary values CAN_PWM_DECODE_NS (the transceiver minimum
decoding margin) and CAN_PWM_NS_MAX (the maximum PWM symbol duration)
are hardcoded for the moment. Note that a transceiver capable of
bitrates higher than 20 Mbps may be able to handle a CAN_PWM_DECODE_NS
below 5 ns. If such transceivers become commercially available, this
code could be revisited to make this parameter configurable. For now,
leave it static.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-9-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The Transceiver Mode Switching (TMS) indicates whether the CAN XL
controller shall use the PWM or NRZ encoding during the data phase.
The term "transceiver mode switching" is used in both ISO 11898-1 and
CiA 612-2 (although only the latter one uses the abbreviation TMS). We
adopt the same naming convention here for consistency.
Add the CAN_CTRLMODE_XL_TMS flag to the list of the CAN control modes.
Add can_validate_xl_flags() to check the coherency of the TMS flag.
That function will be reused in upcoming changes to validate the other
CAN XL flags.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-6-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
CAN XL uses bittiming parameters different from Classical CAN and CAN
FD. Thus, all the data bittiming parameters, including TDC, need to be
duplicated for CAN XL.
Add the CAN XL netlink interface for all the features which are common
with CAN FD. Any new CAN XL specific features are added later on.
The first time CAN XL is activated, the MTU is set by default to
CANXL_MAX_MTU. The user may then configure a custom MTU within the
CANXL_MIN_MTU to CANXL_MAX_MTU range, in which case, the custom MTU
value will be kept as long as CAN XL remains active.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-5-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
ISO 11898-1:2024 adds a new restricted operation mode. This mode is
added as a mandatory feature for nodes which support CAN XL and is
retrofitted as optional for legacy nodes (i.e. the ones which only
support Classical CAN and CAN FD).
The restricted operation mode is nearly the same as the listen only
mode: the node can not send data frames or remote frames and can not
send dominant bits if an error occurs. The only exception is that the
node shall still send the acknowledgment bit. A second niche exception
is that the node may still send a data frame containing a time
reference message if the node is a primary time provider, but because
the time provider feature is not yet implemented in the kernel, this
second exception is not relevant to us at the moment.
Add the CAN_CTRLMODE_RESTRICTED control mode flag and update the
can_dev_dropped_skb() helper function accordingly.
Finally, bail out if both CAN_CTRLMODE_LISTENONLY and
CAN_CTRLMODE_RESTRICTED are provided.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-4-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
