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path: root/drivers/net/can/dev
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2022-11-07can: dev: fix skb drop checkOliver Hartkopp
In commit a6d190f8c767 ("can: skb: drop tx skb if in listen only mode") the priv->ctrlmode element is read even on virtual CAN interfaces that do not create the struct can_priv at startup. This out-of-bounds read may lead to CAN frame drops for virtual CAN interfaces like vcan and vxcan. This patch mainly reverts the original commit and adds a new helper for CAN interface drivers that provide the required information in struct can_priv. Fixes: a6d190f8c767 ("can: skb: drop tx skb if in listen only mode") Reported-by: Dariusz Stojaczyk <Dariusz.Stojaczyk@opensynergy.com> Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Cc: Max Staudt <max@enpas.org> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/all/20221102095431.36831-1-socketcan@hartkopp.net Cc: stable@vger.kernel.org # 6.0.x [mkl: patch pch_can, too] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-09-15can: canxl: update CAN infrastructure for CAN XL framesOliver Hartkopp
- add new ETH_P_CANXL ethernet protocol type - update skb checks for CAN XL - add alloc_canxl_skb() which now needs a data length parameter - introduce init_can_skb_reserve() to reduce code duplication Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/all/20220912170725.120748-6-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-09-15can: set CANFD_FDF flag in all CAN FD frame structuresOliver Hartkopp
To simplify the testing in user space all struct canfd_frame's provided by the CAN subsystem of the Linux kernel now have the CANFD_FDF flag set in canfd_frame::flags. NB: Handcrafted ETH_P_CANFD frames introduced via PF_PACKET socket might not set this bit correctly. During the check for sufficient headroom in PF_PACKET sk_buffs the uninitialized CAN sk_buff data structures are filled. In the case of a CAN FD frame the CANFD_FDF flag is set accordingly. As the CAN frame content is already zero initialized in alloc_canfd_skb() the obsolete initialization of cf->flags in the CTU CAN FD driver has been removed as it would overwrite the already set CANFD_FDF flag. Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/all/20220912170725.120748-4-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-09-15can: skb: add skb CAN frame data length helpersOliver Hartkopp
Add two helpers to retrieve the data length from CAN sk_buffs and prepare the length information to be a uint16 value for the CAN XL support. Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/all/20220912170725.120748-3-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-09-15can: skb: unify skb CAN frame identification helpersOliver Hartkopp
Replace open coded checks for sk_buffs containing Classical CAN and CAN FD frame structures as a preparation for CAN XL support. With the added length check the unintended processing of CAN XL frames having the CANXL_XLF bit set can be suppressed even when the skb->len fits to non CAN XL frames. The CAN_RAW socket needs a rework to use these helpers. Therefore the use of these helpers is postponed to the CAN_RAW CAN XL integration. The J1939 protocol gets a check for Classical CAN frames too. Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Link: https://lore.kernel.org/all/20220912170725.120748-2-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-09-05can: rx-offload: can_rx_offload_init_queue(): fix typoMarc Kleine-Budde
Fix typo "rounted" -> "rounded". Link: https://lore.kernel.org/all/20220811093617.1861938-2-mkl@pengutronix.de Fixes: d254586c3453 ("can: rx-offload: Add support for HW fifo based irq offloading") Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-07-28can: dev: add generic function can_eth_ioctl_hwts()Vincent Mailhol
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 <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/all/20220727101641.198847-9-mailhol.vincent@wanadoo.fr Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-07-28can: dev: add generic function can_ethtool_op_get_ts_info_hwts()Vincent Mailhol
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 <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/all/20220727101641.198847-8-mailhol.vincent@wanadoo.fr Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-07-28can: dev: add hardware TX timestampVincent Mailhol
Because of the loopback feature of socket CAN, hardware TX timestamps are nothing else than the hardware RX timespamp of the corresponding loopback packet. This patch simply reuses the hardware RX timestamp. The rationale to clone this timestamp value is that existing tools which rely of libpcap (such as tcpdump) expect support for both TX and RX hardware timestamps in order to activate the feature (i.e. no granular control to activate either of TX or RX hardware timestamps). Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://lore.kernel.org/all/20220727101641.198847-7-mailhol.vincent@wanadoo.fr Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-07-03can: netlink: dump bitrate 0 if can_priv::bittiming.bitrate is -1UDario Binacchi
Upcoming changes on slcan driver will require you to specify a bitrate of value -1 to prevent the open_candev() from failing but at the same time highlighting that it is a fake value. In this case the command `ip --details -s -s link show' would print 4294967295 as the bitrate value. The patch change this value in 0. Link: https://lore.kernel.org/all/20220628163137.413025-5-dario.binacchi@amarulasolutions.com Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com> Tested-by: Jeroen Hofstee <jhofstee@victronenergy.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-13can: netlink: allow configuring of fixed data bit rates without need for ↵Marc Kleine-Budde
do_set_data_bittiming callback This patch is similar to 7e193a42c37c ("can: netlink: allow configuring of fixed bit rates without need for do_set_bittiming callback") but for data bit rates instead of bit rates. Usually CAN devices support configurable data bit rates. The limits are defined by struct can_priv::data_bittiming_const. Another way is to implement the struct can_priv::do_set_data_bittiming callback. If the bit rate is configured via netlink, the can_changelink() function checks that either can_priv::data_bittiming_const or struct can_priv::do_set_data_bittiming is implemented. In commit 431af779256c ("can: dev: add CAN interface API for fixed bitrates") an API for configuring bit rates on CAN interfaces that only support fixed bit rates was added. The supported bit rates are defined by struct can_priv::bitrate_const. However the above mentioned commit forgot to add the struct can_priv::data_bitrate_const to the check in can_changelink(). In order to avoid to implement a no-op can_priv::do_set_data_bittiming callback on devices with fixed data bit rates, extend the check in can_changelink() accordingly. Link: https://lore.kernel.org/all/20220613143633.4151884-1-mkl@pengutronix.de Fixes: 431af779256c ("can: dev: add CAN interface API for fixed bitrates") Acked-by: Max Staudt <max@enpas.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11can: skb: drop tx skb if in listen only modeVincent Mailhol
Frames can be directly injected to a can driver via the packet socket. By doing so, it is possible to reach the net_device_ops::ndo_start_xmit function even if the driver is configured in listen only mode. Add a check in can_dropped_invalid_skb() to discard the skb if CAN_CTRLMODE_LISTENONLY is set. Link: https://lore.kernel.org/all/20220610143009.323579-8-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Max Staudt <max@enpas.org> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11can: skb: move can_dropped_invalid_skb() and can_skb_headroom_valid() to skb.cVincent Mailhol
The functions can_dropped_invalid_skb() and can_skb_headroom_valid() grew a lot over the years to a point which it does not make much sense to have them defined as static inline in header files. Move those two functions to the .c counterpart of skb.h. can_skb_headroom_valid()'s only caller being can_dropped_invalid_skb(), the declaration is removed from the header. Only can_dropped_invalid_skb() gets its symbol exported. While doing so, do a small cleanup: add brackets around the else block in can_dropped_invalid_skb(). Link: https://lore.kernel.org/all/20220610143009.323579-7-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Reported-by: kernel test robot <lkp@intel.com> Acked-by: Max Staudt <max@enpas.org> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11can: Kconfig: add CONFIG_CAN_RX_OFFLOADVincent Mailhol
Only a few drivers rely on the CAN rx offload framework (as of the writing of this patch, only four: flexcan, m_can, mcp251xfd and ti_hecc). Split it out of can-dev and add a new config symbol: CAN_RX_OFFLOAD. The drivers relying on CAN rx offload are in different sub folders. Make CAN_RX_OFFLOAD an hidden option and tag all the drivers depending on that feature with "select CAN_RX_OFFLOAD" so that the option gets automatically enabled if and only if one of those drivers is chosen. Link: https://lore.kernel.org/all/20220610143009.323579-5-mailhol.vincent@wanadoo.fr Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Max Staudt <max@enpas.org> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11can: bittiming: move bittiming calculation functions to calc_bittiming.cVincent Mailhol
The canonical way to select or deselect an object during compilation is to use this pattern in the relevant Makefile: bar-$(CONFIG_FOO) := foo.o bittiming.c instead uses some #ifdef CONFIG_CAN_CALC_BITTIMG. Create a new file named calc_bittiming.c with all the functions which are conditionally compiled with CONFIG_CAN_CALC_BITTIMG and modify the Makefile according to above pattern. Link: https://lore.kernel.org/all/20220610143009.323579-4-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Max Staudt <max@enpas.org> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11can: Kconfig: turn menu "CAN Device Drivers" into a menuconfig using CAN_DEVVincent Mailhol
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/20220610143009.323579-3-mailhol.vincent@wanadoo.fr Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Max Staudt <max@enpas.org> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11can: Kconfig: rename config symbol CAN_DEV into CAN_NETLINKVincent Mailhol
In the next patches, the scope of the can-dev module will grow to engloble the software/virtual drivers (slcan, v(x)can). To this extent, release CAN_DEV by renaming it into CAN_NETLINK. The config symbol CAN_DEV will be reused to cover this extended scope. The rationale for the name CAN_NETLINK is that netlink is the predominant feature added here. The current description only mentions platform drivers despite the fact that this symbol is also required by "normal" devices (e.g. USB or PCI) which do not fall under the platform devices category. The description is updated accordingly to fix this gap. Link: https://lore.kernel.org/all/20220610143009.323579-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Max Staudt <max@enpas.org> Tested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-06-11can: netlink: allow configuring of fixed bit rates without need for ↵Marc Kleine-Budde
do_set_bittiming callback Usually CAN devices support configurable bit rates. The limits are defined by struct can_priv::bittiming_const. Another way is to implement the struct can_priv::do_set_bittiming callback. If the bit rate is configured via netlink, the can_changelink() function checks that either can_priv::bittiming_const or struct can_priv::do_set_bittiming is implemented. In commit 431af779256c ("can: dev: add CAN interface API for fixed bitrates") an API for configuring bit rates on CAN interfaces that only support fixed bit rates was added. The supported bit rates are defined by struct can_priv::bitrate_const. However the above mentioned commit forgot to add the struct can_priv::bitrate_const to the check in can_changelink(). In order to avoid to implement a no-op can_priv::do_set_bittiming callback on devices with fixed bit rates, extend the check in can_changelink() accordingly. Link: https://lore.kernel.org/all/20220611144248.3924903-1-mkl@pengutronix.de Fixes: 431af779256c ("can: dev: add CAN interface API for fixed bitrates") Reported-by: Max Staudt <max@enpas.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-05-19can: can-dev: remove obsolete CAN LED supportOliver Hartkopp
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/20220518154527.29046-1-socketcan@hartkopp.net Suggested-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> [mkl: remove led.h from MAINTAINERS] Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-05-19can: can-dev: move to netif_napi_add_weight()Jakub Kicinski
We want to remove the weight argument from the basic version of the netif_napi_add() call. Move all the callers in drivers/net/can that pass a custom weight (i.e. not NAPI_POLL_WEIGHT or 64) to the netif_napi_add_weight() API. Link: https://lore.kernel.org/all/20220517002345.1812104-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-04-19can: bittiming: can_calc_bittiming(): prefer small bit rate pre-scalers over ↵Marc Kleine-Budde
larger ones The CiA (CAN in Automation) lists in their Newsletter 1/2018 in the "Recommendation for the CAN FD bit-timing" [1] article several recommendations, one of them is: | Recommendation 3: Choose BRPA and BRPD as low as possible [1] https://can-newsletter.org/uploads/media/raw/f6a36d1461371a2f86ef0011a513712c.pdf With the current bit timing algorithm Srinivas Neeli noticed that on the Xilinx Versal ACAP board the CAN data bit timing parameters are not calculated optimally. For most bit rates, the bit rate prescaler (BRP) is != 1, although it's possible to configure the requested with a bit rate with a prescaler of 1: | Data Bit timing parameters for xilinx_can_fd2i with 79.999999 MHz ref clock (cmd-line) using algo 'v4.8' | nominal real Bitrt nom real SampP | Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error | 12000000 12 2 2 2 1 1 11428571 4.8% 75.0% 71.4% 4.8% | 10000000 25 1 1 1 1 2 9999999 0.0% 75.0% 75.0% 0.0% | 8000000 12 3 3 3 1 1 7999999 0.0% 75.0% 70.0% 6.7% | 5000000 50 1 1 1 1 4 4999999 0.0% 75.0% 75.0% 0.0% | 4000000 62 1 1 1 1 5 3999999 0.0% 75.0% 75.0% 0.0% | 2000000 125 1 1 1 1 10 1999999 0.0% 75.0% 75.0% 0.0% | 1000000 250 1 1 1 1 20 999999 0.0% 75.0% 75.0% 0.0% The bit timing parameter calculation algorithm iterates effectively from low to high BRP values. It selects a new best parameter set, if the sample point error of the current parameter set is equal or less to old best parameter set. If the given hardware constraints (clock rate and bit timing parameter constants) don't allow a sample point error of 0, the algorithm will first find a valid bit timing parameter set with a low BRP, but then will accept parameter sets with higher BRPs that have the same sample point error. This patch changes the algorithm to only accept a new parameter set, if the resulting sample point error is lower. This leads to the following data bit timing parameter for the Versal ACAP board: | Data Bit timing parameters for xilinx_can_fd2i with 79.999999 MHz ref clock (cmd-line) using algo 'can-next' | nominal real Bitrt nom real SampP | Bitrate TQ[ns] PrS PhS1 PhS2 SJW BRP Bitrate Error SampP SampP Error | 12000000 12 2 2 2 1 1 11428571 4.8% 75.0% 71.4% 4.8% | 10000000 12 2 3 2 1 1 9999999 0.0% 75.0% 75.0% 0.0% | 8000000 12 3 3 3 1 1 7999999 0.0% 75.0% 70.0% 6.7% | 5000000 12 5 6 4 1 1 4999999 0.0% 75.0% 75.0% 0.0% | 4000000 12 7 7 5 1 1 3999999 0.0% 75.0% 75.0% 0.0% | 2000000 12 14 15 10 1 1 1999999 0.0% 75.0% 75.0% 0.0% | 1000000 25 14 15 10 1 2 999999 0.0% 75.0% 75.0% 0.0% Note: Due to HW constraints a data bit rate of 1 MBit/s with BRP = 1 is not possible. Link: https://lore.kernel.org/all/20220318144913.873614-1-mkl@pengutronix.de Link: https://lore.kernel.org/all/20220113203004.jf2rqj2pirhgx72i@pengutronix.de Cc: Srinivas Neeli <sneeli@xilinx.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-04-19can: rx-offload: rename can_rx_offload_queue_sorted() -> ↵Marc Kleine-Budde
can_rx_offload_queue_timestamp() This patch renames the function can_rx_offload_queue_sorted() to can_rx_offload_queue_timestamp(). This better describes what the function does, it adds a newly RX'ed skb to the sorted queue by its timestamp. Link: https://lore.kernel.org/all/20220417194327.2699059-1-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-03-06can: Use netif_rx().Sebastian Andrzej Siewior
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 <mkl@pengutronix.de> Cc: Oliver Hartkopp <socketcan@hartkopp.net> Cc: Wolfgang Grandegger <wg@grandegger.com> Cc: linux-can@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-24can: bittiming: mark function arguments and local variables as constMarc Kleine-Budde
This patch marks the arguments of some functions as well as some local variables as constant. Link: https://lore.kernel.org/all/20220124215642.3474154-7-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-02-24can: bittiming: can_validate_bitrate(): simplify bit rate checkingMarc Kleine-Budde
This patch simplifies the validation of the fixed bit rates. If a supported bit rate is found, directly return 0. If no valid bit rate is found return -EINVAL; Link: https://lore.kernel.org/all/20220124215642.3474154-6-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: netlink: report the CAN controller mode supported flagsVincent Mailhol
Currently, the CAN netlink interface provides no easy ways to check the capabilities of a given controller. The only method from the command line is to try each CAN_CTRLMODE_* individually to check whether the netlink interface returns an -EOPNOTSUPP error or not (alternatively, one may find it easier to directly check the source code of the driver instead...) This patch introduces a method for the user to check both the supported and the static capabilities. The proposed method introduces a new IFLA nest: IFLA_CAN_CTRLMODE_EXT which extends the current IFLA_CAN_CTRLMODE. This is done to guaranty a full forward and backward compatibility between the kernel and the user land applications. The IFLA_CAN_CTRLMODE_EXT nest contains one single entry: IFLA_CAN_CTRLMODE_SUPPORTED. Because this entry is only used in one direction: kernel to userland, no new struct nla_policy are introduced. Below table explains how IFLA_CAN_CTRLMODE_SUPPORTED (hereafter: "supported") and can_ctrlmode::flags (hereafter: "flags") allow us to identify both the supported and the static capabilities, when masked with any of the CAN_CTRLMODE_* bit flags: supported & flags & Controller capabilities CAN_CTRLMODE_* CAN_CTRLMODE_* ----------------------------------------------------------------------- false false Feature not supported (always disabled) false true Static feature (always enabled) true false Feature supported but disabled true true Feature supported and enabled Link: https://lore.kernel.org/all/20211213160226.56219-5-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: dev: replace can_priv::ctrlmode_static by can_get_static_ctrlmode()Vincent Mailhol
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/20211213160226.56219-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: do not increase rx_bytes statistics for RTR framesVincent Mailhol
The actual payload length of the CAN Remote Transmission Request (RTR) frames is always 0, i.e. no payload is transmitted on the wire. However, those RTR frames still use the DLC to indicate the length of the requested frame. As such, net_device_stats::rx_bytes should not be increased for the RTR frames. This patch fixes all the CAN drivers. Link: https://lore.kernel.org/all/20211207121531.42941-5-mailhol.vincent@wanadoo.fr Cc: Marc Kleine-Budde <mkl@pengutronix.de> Cc: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Ludovic Desroches <ludovic.desroches@microchip.com> Cc: Chandrasekar Ramakrishnan <rcsekar@samsung.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Chen-Yu Tsai <wens@csie.org> Cc: Jernej Skrabec <jernej.skrabec@gmail.com> Cc: Yasushi SHOJI <yashi@spacecubics.com> Cc: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com> Cc: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> Cc: Michal Simek <michal.simek@xilinx.com> Cc: Stephane Grosjean <s.grosjean@peak-system.com> Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2 Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-01-05can: do not increase rx statistics when generating a CAN rx error message frameVincent Mailhol
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/20211207121531.42941-2-mailhol.vincent@wanadoo.fr CC: Marc Kleine-Budde <mkl@pengutronix.de> CC: Nicolas Ferre <nicolas.ferre@microchip.com> CC: Alexandre Belloni <alexandre.belloni@bootlin.com> CC: Ludovic Desroches <ludovic.desroches@microchip.com> CC: Chandrasekar Ramakrishnan <rcsekar@samsung.com> CC: Maxime Ripard <mripard@kernel.org> CC: Chen-Yu Tsai <wens@csie.org> CC: Jernej Skrabec <jernej.skrabec@gmail.com> CC: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com> CC: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> CC: Michal Simek <michal.simek@xilinx.com> CC: Stephane Grosjean <s.grosjean@peak-system.com> Tested-by: Jimmy Assarsson <extja@kvaser.com> # kvaser Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Acked-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2 Tested-by: Stefan Mätje <stefan.maetje@esd.eu> # esd_usb2 Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-12-08can: bittiming: replace CAN units with the generic ones from linux/units.hVincent Mailhol
In [1], we introduced a set of units in linux/can/bittiming.h. Since then, generic SI prefixes were added to linux/units.h in [2]. Those new prefixes can perfectly replace CAN specific ones. This patch replaces all occurrences of the CAN units with their corresponding prefix (from linux/units) and the unit (as a comment) according to below table. CAN units SI metric prefix (from linux/units) + unit (as a comment) ------------------------------------------------------------------------ CAN_KBPS KILO /* BPS */ CAN_MBPS MEGA /* BPS */ CAM_MHZ MEGA /* Hz */ The definition are then removed from linux/can/bittiming.h [1] commit 1d7750760b70 ("can: bittiming: add CAN_KBPS, CAN_MBPS and CAN_MHZ macros") [2] commit 26471d4a6cf8 ("units: Add SI metric prefix definitions") Link: https://lore.kernel.org/all/20211124014536.782550-1-mailhol.vincent@wanadoo.fr Suggested-by: Jimmy Assarsson <extja@kvaser.com> Suggested-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: netlink: add can_priv::do_get_auto_tdcv() to retrieve tdcv from deviceVincent Mailhol
Some CAN device can measure the TDCV (Transmission Delay Compensation Value) automatically for each transmitted CAN frames. A callback function do_get_auto_tdcv() is added to retrieve that value. This function is used only if CAN_CTRLMODE_TDC_AUTO is enabled (if CAN_CTRLMODE_TDC_MANUAL is selected, the TDCV value is provided by the user). If the device does not support reporting of TDCV, do_get_auto_tdcv() should be set to NULL and TDCV will not be reported by the netlink interface. On success, do_get_auto_tdcv() shall return 0. If the value can not be measured by the device, for example because network is down or because no frames were transmitted yet, can_priv::do_get_auto_tdcv() shall return a negative error code (e.g. -EINVAL) to signify that the value is not yet available. In such cases, TDCV is not reported by the netlink interface. Link: https://lore.kernel.org/all/20210918095637.20108-6-mailhol.vincent@wanadoo.fr CC: Stefan Mätje <stefan.maetje@esd.eu> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: netlink: add interface for CAN-FD Transmitter Delay Compensation (TDC)Vincent Mailhol
Add the netlink interface for TDC parameters of struct can_tdc_const and can_tdc. Contrary to the can_bittiming(_const) structures for which there is just a single IFLA_CAN(_DATA)_BITTMING(_CONST) entry per structure, here, we create a nested entry IFLA_CAN_TDC. Within this nested entry, additional IFLA_CAN_TDC_TDC* entries are added for each of the TDC parameters of the newly introduced struct can_tdc_const and struct can_tdc. For struct can_tdc_const, these are: IFLA_CAN_TDC_TDCV_MIN IFLA_CAN_TDC_TDCV_MAX IFLA_CAN_TDC_TDCO_MIN IFLA_CAN_TDC_TDCO_MAX IFLA_CAN_TDC_TDCF_MIN IFLA_CAN_TDC_TDCF_MAX For struct can_tdc, these are: IFLA_CAN_TDC_TDCV IFLA_CAN_TDC_TDCO IFLA_CAN_TDC_TDCF This is done so that changes can be applied in the future to the structures without breaking the netlink interface. The TDC netlink logic works as follow: * CAN_CTRLMODE_FD is not provided: - if any TDC parameters are provided: error. - TDC parameters not provided: TDC parameters unchanged. * CAN_CTRLMODE_FD is provided and is false: - TDC is deactivated: both the structure and the CAN_CTRLMODE_TDC_{AUTO,MANUAL} flags are flushed. * CAN_CTRLMODE_FD provided and is true: - CAN_CTRLMODE_TDC_{AUTO,MANUAL} and tdc{v,o,f} not provided: call can_calc_tdco() to automatically decide whether TDC should be activated and, if so, set CAN_CTRLMODE_TDC_AUTO and uses the calculated tdco value. - CAN_CTRLMODE_TDC_AUTO and tdco provided: set CAN_CTRLMODE_TDC_AUTO and use the provided tdco value. Here, tdcv is illegal and tdcf is optional. - CAN_CTRLMODE_TDC_MANUAL and both of tdcv and tdco provided: set CAN_CTRLMODE_TDC_MANUAL and use the provided tdcv and tdco value. Here, tdcf is optional. - CAN_CTRLMODE_TDC_{AUTO,MANUAL} are mutually exclusive. Whenever one flag is turned on, the other will automatically be turned off. Providing both returns an error. - Combination other than the one listed above are illegal and will return an error. N.B. above rules mean that whenever CAN_CTRLMODE_FD is provided, the previous TDC values will be overwritten. The only option to reuse previous TDC value is to not provide CAN_CTRLMODE_FD. All the new parameters are defined as u32. This arbitrary choice is done to mimic the other bittiming values with are also all of type u32. An u16 would have been sufficient to hold the TDC values. This patch completes below series (c.f. [1]): - commit 289ea9e4ae59 ("can: add new CAN FD bittiming parameters: Transmitter Delay Compensation (TDC)") - commit c25cc7993243 ("can: bittiming: add calculation for CAN FD Transmitter Delay Compensation (TDC)") [1] https://lore.kernel.org/linux-can/20210224002008.4158-1-mailhol.vincent@wanadoo.fr/T/#t Link: https://lore.kernel.org/all/20210918095637.20108-5-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: bittiming: change can_calc_tdco()'s prototype to not directly modify privVincent Mailhol
The function can_calc_tdco() directly retrieves can_priv from the net_device and directly modifies it. This is annoying for the upcoming patch. In drivers/net/can/dev/netlink.c:can_changelink(), the data bittiming are written to a temporary structure and memcpyed to can_priv only after everything succeeded. In the next patch, where we will introduce the netlink interface for TDC parameters, we will add a new TDC block which can potentially fail. For this reason, the data bittiming temporary structure has to be copied after that to-be-introduced TDC block. However, TDC also needs to access data bittiming information. We change the prototype so that the data bittiming structure is passed to can_calc_tdco() as an argument instead of retrieving it from priv. This way can_calc_tdco() can access the data bittiming before it gets memcpyed to priv. Link: https://lore.kernel.org/all/20210918095637.20108-4-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: bittiming: change unit of TDC parameters to clock periodsVincent Mailhol
In the current implementation, all Transmission Delay Compensation (TDC) parameters are expressed in time quantum. However, ISO 11898-1 actually specifies that these should be expressed in *minimum* time quantum. Furthermore, the minimum time quantum is specified to be "one node clock period long" (c.f. paragraph 11.3.1.1 "Bit time"). For sake of simplicity, we prefer to use the "clock period" term instead of "minimum time quantum" because we believe that it is more broadly understood. This patch fixes that discrepancy by updating the documentation and the formula for TDCO calculation. N.B. In can_calc_tdco(), the sample point (in time quantum) was calculated using a division, thus introducing a risk of rounding and truncation errors. On top of changing the unit to clock period, we also modified the formula to use only additions. Link: https://lore.kernel.org/all/20210918095637.20108-3-mailhol.vincent@wanadoo.fr Suggested-by: Stefan Mätje <Stefan.Maetje@esd.eu> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: bittiming: allow TDC{V,O} to be zero and add can_tdc_const::tdc{v,o,f}_minVincent Mailhol
ISO 11898-1 specifies in section 11.3.3 "Transmitter delay compensation" that "the configuration range for [the] SSP position shall be at least 0 to 63 minimum time quanta." Because SSP = TDCV + TDCO, it means that we should allow both TDCV and TDCO to hold zero value in order to honor SSP's minimum possible value. However, current implementation assigned special meaning to TDCV and TDCO's zero values: * TDCV = 0 -> TDCV is automatically measured by the transceiver. * TDCO = 0 -> TDC is off. In order to allow for those values to really be zero and to maintain current features, we introduce two new flags: * CAN_CTRLMODE_TDC_AUTO indicates that the controller support automatic measurement of TDCV. * CAN_CTRLMODE_TDC_MANUAL indicates that the controller support manual configuration of TDCV. N.B.: current implementation failed to provide an option for the driver to indicate that only manual mode was supported. TDC is disabled if both CAN_CTRLMODE_TDC_AUTO and CAN_CTRLMODE_TDC_MANUAL flags are off, c.f. the helper function can_tdc_is_enabled() which is also introduced in this patch. Also, this patch adds three fields: tdcv_min, tdco_min and tdcf_min to struct can_tdc_const. While we are not convinced that those three fields could be anything else than zero, we can imagine that some controllers might specify a lower bound on these. Thus, those minimums are really added "just in case". Comments of struct can_tdc and can_tdc_const are updated accordingly. Finally, the changes are applied to the etas_es58x driver. Link: https://lore.kernel.org/all/20210918095637.20108-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-10-24can: bittiming: can_fixup_bittiming(): change type of tseg1 and alltseg to ↵Marc Kleine-Budde
unsigned int All timing calculation is done with unsigned integers, so change type of tseg1 and alltseg to unsigned int, too. Link: https://lore.kernel.org/all/20211013130653.1513627-1-mkl@pengutronix.de Link: https://github.com/linux-can/can-utils/pull/314 Reported-by: Gary Bisson <bisson.gary@gmail.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-08-19can: netlink: allow user to turn off unsupported featuresVincent Mailhol
The sanity checks on the control modes will reject any request related to an unsupported features, even turning it off. Example on an interface which does not support CAN-FD: $ ip link set can0 type can bitrate 500000 fd off RTNETLINK answers: Operation not supported This patch lets such command go through (but requests to turn on an unsupported feature are, of course, still denied). Link: https://lore.kernel.org/r/20210815033248.98111-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-08-19can: dev: provide optional GPIO based termination supportOleksij Rempel
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/20210818071232.20585-4-o.rempel@pengutronix.de Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: netlink: remove redundant check in can_validate()Vincent Mailhol
can_validate() does a first check: | if (is_can_fd) { | if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING]) | return -EOPNOTSUPP; | } If that first if succeeds, we know that if is_can_fd is true then data[IFLA_CAN_BITTIMING is set. However, the next if switch does not leverage on above knowledge and redoes the check: | if (data[IFLA_CAN_DATA_BITTIMING]) { | if (!is_can_fd || !data[IFLA_CAN_BITTIMING]) | ^~~~~~~~~~~~~~~~~~~~~~~~ | return -EOPNOTSUPP; | } This patch removes that redundant check. Link: https://lore.kernel.org/r/20210603151550.140727-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: netlink: clear data_bittiming if FD is turned offVincent Mailhol
When the FD is turned off through the netlink interface, the data bit timing values still remain in data_bittiming and are displayed despite of the feature being disabled. Example: | $ ip link set can0 type can bitrate 500000 dbitrate 2000000 fd on | $ ip --details link show can0 | 1: can0: <NOARP,ECHO> mtu 72 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 10 | link/can promiscuity 0 minmtu 0 maxmtu 0 | can <FD> state STOPPED restart-ms 0 | bitrate 500000 sample-point 0.875 | tq 12 prop-seg 69 phase-seg1 70 phase-seg2 20 sjw 1 | ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp-inc 1 | dbitrate 2000000 dsample-point 0.750 | dtq 12 dprop-seg 14 dphase-seg1 15 dphase-seg2 10 dsjw 1 | ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 dbrp-inc 1 | clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 | | $ ip link set can0 type can bitrate 500000 fd off | $ ip --details link show can0 | 1: can0: <NOARP,ECHO> mtu 16 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 10 | link/can promiscuity 0 minmtu 0 maxmtu 0 | can state STOPPED restart-ms 0 | bitrate 500000 sample-point 0.875 | tq 12 prop-seg 69 phase-seg1 70 phase-seg2 20 sjw 1 | ES582.1/ES584.1: tseg1 2..256 tseg2 2..128 sjw 1..128 brp 1..512 brp-inc 1 | dbitrate 2000000 dsample-point 0.750 | dtq 12 dprop-seg 14 dphase-seg1 15 dphase-seg2 10 dsjw 1 | ES582.1/ES584.1: dtseg1 2..32 dtseg2 1..16 dsjw 1..8 dbrp 1..32 dbrp-inc 1 | clock 80000000 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535 Remark: once FD is turned off, it is not possible to turn fd back on and reuse the previously input data bit timing values: | $ ip link set can0 type can bitrate 500000 fd on | RTNETLINK answers: Operation not supported This means that the user will need to re-configure the data bit timing in order to turn fd on again. Because old data bit timing values cannot be reused, this patch clears priv->data_bit timing whenever FD is turned off. This way, the data bit timing variables are not displayed anymore. Link: https://lore.kernel.org/r/20210618081904.141114-2-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to ↵Marc Kleine-Budde
be called from threaded interrupt After reading all CAN frames from the controller in the IRQ handler and storing them into a skb_queue, the driver calls napi_schedule(). In the napi poll function the skb from the skb_queue are then pushed into the networking stack. However if napi_schedule() is called from a threaded IRQ handler this triggers the following error: | NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!! To avoid this, create a new rx-offload function (can_rx_offload_threaded_irq_finish()) with a call to local_bh_disable()/local_bh_enable() around the napi_schedule() call. Convert all drivers that call can_rx_offload_irq_finish() from threaded IRQ context to can_rx_offload_threaded_irq_finish(). Link: https://lore.kernel.org/r/20210724204745.736053-4-mkl@pengutronix.de Suggested-by: Daniel Glöckner <dg@emlix.com> Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: rx-offload: can_rx_offload_irq_finish(): directly call napi_schedule()Marc Kleine-Budde
Instead of calling can_rx_offload_schedule() call napi_schedule() directly. As this was the last use of can_rx_offload_schedule() remove this helper function. Link: https://lore.kernel.org/r/20210724204745.736053-3-mkl@pengutronix.de Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-07-25can: rx-offload: add skb queue for use during ISRMarc Kleine-Budde
Adding a skb to the skb_queue in rx-offload requires to take a lock. This commit avoids this by adding an unlocked skb queue that is appended at the end of the ISR. Having one lock at the end of the ISR should be OK as the HW is empty, not about to overflow. Link: https://lore.kernel.org/r/20210724204745.736053-2-mkl@pengutronix.de Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Co-developed-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-04-07can: skb: alloc_can{,fd}_skb(): set "cf" to NULL if skb allocation failsMarc Kleine-Budde
The handling of CAN bus errors typically consist of allocating a CAN error SKB using alloc_can_err_skb() followed by stats handling and filling the error details in the newly allocated CAN error SKB. Even if the allocation of the SKB fails the stats handling should not be skipped. The common pattern in CAN drivers is to allocate the skb and work on the struct can_frame pointer "cf", if it has been assigned by alloc_can_err_skb(). | skb = alloc_can_err_skb(priv->ndev, &cf); | | /* RX errors */ | if (bdiag1 & (MCP251XFD_REG_BDIAG1_DCRCERR | | MCP251XFD_REG_BDIAG1_NCRCERR)) { | netdev_dbg(priv->ndev, "CRC error\n"); | | stats->rx_errors++; | if (cf) | cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ; | } In case of an OOM alloc_can_err_skb() returns NULL, but doesn't set "cf" to NULL as well. For the above pattern to work the "cf" has to be initialized to NULL, which is easily forgotten. To solve this kind of problems, set "cf" to NULL if alloc_can_err_skb() returns NULL. Link: https://lore.kernel.org/r/20210402102245.1512583-1-mkl@pengutronix.de Suggested-by: Vincent MAILHOL <mailhol.vincent@wanadoo.fr> Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: bittiming: add CAN_KBPS, CAN_MBPS and CAN_MHZ macrosVincent Mailhol
Add three macro to simplify the readability of big bit timing numbers: - CAN_KBPS: kilobits per second (one thousand) - CAN_MBPS: megabits per second (one million) - CAN_MHZ: megahertz per second (one million) Example: u32 bitrate_max = 8 * CAN_MBPS; struct can_clock clock = {.freq = 80 * CAN_MHZ}; instead of: u32 bitrate_max = 8000000; struct can_clock clock = {.freq = 80000000}; Apply the new macro to driver/net/can/dev/bittiming.c. Link: https://lore.kernel.org/r/20210306054040.76483-1-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: bittiming: add calculation for CAN FD Transmitter Delay Compensation (TDC)Vincent Mailhol
The logic for the tdco calculation is to just reuse the normal sample point: tdco = sp. Because the sample point is expressed in tenth of percent and the tdco is expressed in time quanta, a conversion is needed. At the end, ssp = tdcv + tdco = tdcv + sp. Another popular method is to set tdco to the middle of the bit: tdc->tdco = can_bit_time(dbt) / 2 During benchmark tests, we could not find a clear advantages for one of the two methods. The tdco calculation is triggered each time the data_bittiming is changed so that users relying on automated calculation can use the netlink interface the exact same way without need of new parameters. For example, a command such as: ip link set canX type can bitrate 500000 dbitrate 4000000 fd on would trigger the calculation. The user using CONFIG_CAN_CALC_BITTIMING who does not want automated calculation needs to manually set tdco to zero. For example with: ip link set canX type can tdco 0 bitrate 500000 dbitrate 4000000 fd on (if the tdco parameter is provided in a previous command, it will be overwritten). If tdcv is set to zero (default), it is automatically calculated by the transiver for each frame. As such, there is no code in the kernel to calculate it. tdcf has no automated calculation functions because we could not figure out a formula for this parameter. Link: https://lore.kernel.org/r/20210224002008.4158-6-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: netlink: move '=' operators back to previous line (checkpatch fix)Vincent Mailhol
Fix the warning triggered by having an '=' at the beginning of the line by moving it back to the previous line. Also replace all indentations with a single space so that future entries can be more easily added. Extract of ./scripts/checkpatch.pl -f drivers/net/can/dev/netlink.c: CHECK: Assignment operator '=' should be on the previous line + [IFLA_CAN_BITTIMING_CONST] + = { .len = sizeof(struct can_bittiming_const) }, CHECK: Assignment operator '=' should be on the previous line + [IFLA_CAN_DATA_BITTIMING] + = { .len = sizeof(struct can_bittiming) }, CHECK: Assignment operator '=' should be on the previous line + [IFLA_CAN_DATA_BITTIMING_CONST] + = { .len = sizeof(struct can_bittiming_const) }, Link: https://lore.kernel.org/r/20210224002008.4158-4-mailhol.vincent@wanadoo.fr Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: dev: can_free_echo_skb(): extend to return can frame lengthMarc Kleine-Budde
In order to implement byte queue limits (bql) in CAN drivers, the length of the CAN frame needs to be passed into the networking stack even if the transmission failed for some reason. To avoid to calculate this length twice, extend can_free_echo_skb() to return that value. Convert all users of this function, too. This patch is the natural extension of commit: | 9420e1d495e2 ("can: dev: can_get_echo_skb(): extend to return can | frame length") Link: https://lore.kernel.org/r/20210319142700.305648-3-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: dev: can_free_echo_skb(): don't crash the kernel if can_priv::echo_skb ↵Marc Kleine-Budde
is accessed out of bounds A out of bounds access to "struct can_priv::echo_skb" leads to a kernel crash. Better print a sensible warning message instead and try to recover. This patch is similar to: | e7a6994d043a ("can: dev: __can_get_echo_skb(): Don't crash the kernel | if can_priv::echo_skb is accessed out of bounds") Link: https://lore.kernel.org/r/20210319142700.305648-2-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-03-30can: dev: always create TX echo skbMarc Kleine-Budde
So far the creation of the TX echo skb was optional and can be controlled by the local sender of a CAN frame. It turns out that the TX echo CAN skb can be piggybacked to carry information in the driver from the TX- to the TX-complete handler. Several drivers already use the return value of can_get_echo_skb() (which is the length of the data field in the CAN frame) for their number of transferred bytes statistics. The statistics are not working if CAN echo skbs are disabled. Another use case is to calculate and set the CAN frame length on the wire, which is needed for BQL support in both the TX and TX-completion handler. For now in can_put_echo_skb(), which is called from the TX handler, the skb carrying the CAN frame is discarded if no TX echo is requested, leading to the above illustrated problems. This patch changes the can_put_echo_skb() function, so that the echo skb is always generated. If the sender requests no echo, the echo skb is consumed in __can_get_echo_skb() without being passed into the RX handler of the networking stack, but the CAN data length and CAN frame length information is properly returned. Link: https://lore.kernel.org/r/20210309211904.3348700-1-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>