can: dev: fix skb drop check

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>

can: tree-wide: advertise software timestamping capabilities

Currently, some CAN drivers support hardware timestamping, some do
not. But userland has no method to query which features are supported
(aside maybe of getting RX messages and observe whether or not
hardware timestamps stay at zero).

The canonical way for a network driver to advertised what kind of
timestamping it supports is to implement ethtool_ops::get_ts_info().

This patch only targets the CAN drivers which *do not* support
hardware timestamping. For each of those CAN drivers, implement the
get_ts_info() using the generic ethtool_op_get_ts_info().

This way, userland can do:

| $ ethtool --show-time-stamping canX

to confirm the device timestamping capacities.

N.B. the drivers which support hardware timestamping will be migrated
in separate patches.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-6-mailhol.vincent@wanadoo.fr
[mkl: mscan: add missing mscan_ethtool_ops]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: add CAN_ERR_CNT flag to notify availability of error counter

Add a dedicated flag in uapi/linux/can/error.h to notify the userland
that fields data[6] and data[7] of the CAN error frame were
respectively populated with the tx and rx error counters.

For all driver tree-wide, set up this flags whenever needed.

Link: https://lore.kernel.org/all/20220719143550.3681-12-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: do not report txerr and rxerr during bus-off

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 57e83fb9b746 ("can: hi311x: Add Holt HI-311x CAN driver")
Link: https://lore.kernel.org/all/20220719143550.3681-6-mailhol.vincent@wanadoo.fr
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

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/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>

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 <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>

spi: make remove callback a void function

The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

can: do not increase tx_bytes statistics for RTR frames

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::tx_bytes should not be increased when
sending RTR frames.

The function can_get_echo_skb() already returns the correct length,
even for RTR frames (c.f. [1]). However, for historical reasons, the
drivers do not use can_get_echo_skb()'s return value and instead, most
of them store a temporary length (or dlc) in some local structure or
array. Using the return value of can_get_echo_skb() solves the
issue. After doing this, such length/dlc fields become unused and so
this patch does the adequate cleaning when needed.

This patch fixes all the CAN drivers.

Finally, can_get_echo_skb() is decorated with the __must_check
attribute in order to force future drivers to correctly use its return
value (else the compiler would emit a warning).

[1] commit ed3320cec279 ("can: dev: __can_get_echo_skb():
fix real payload length return value for RTR frames")

Link: https://lore.kernel.org/all/20211207121531.42941-6-mailhol.vincent@wanadoo.fr
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.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: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Cc: Andreas Larsson <andreas@gaisler.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
[mkl: add conversion for grcan]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: do not increase rx_bytes statistics for RTR frames

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>

can: hi311x: hi3110_can_probe(): convert to use dev_err_probe()

When deferred the reason is saved for further debugging. Besides that,
it's fine to call dev_err_probe() in ->probe() when error code is
known. Convert the driver to use dev_err_probe().

Link: https://lore.kernel.org/all/20211206165542.69887-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: hi3110_can_probe(): make use of device property API

Make use of device property API in this driver so that both OF based
system and ACPI based system can use this driver.

Link: https://lore.kernel.org/all/20211206165542.69887-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: hi3110_can_probe(): try to get crystal clock rate from property

In some configurations, mainly ACPI-based, the clock frequency of the
device is supplied by very well established 'clock-frequency'
property. Hence, try to get it from the property at last if no other
providers are available.

Link: https://lore.kernel.org/all/20211206165542.69887-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: hi3110_can_probe(): use devm_clk_get_optional() to get the input clock

It's not clear what was the intention of redundant usage of IS_ERR()
around the clock pointer since with the error check of devm_clk_get()
followed by bailout it can't be invalid,

Simplify the code which fetches the input clock by using
devm_clk_get_optional(). It will allow to switch to device properties
approach in the future.

Link: https://lore.kernel.org/all/20211206165542.69887-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: fix a signedness bug in hi3110_cmd()

The hi3110_cmd() is supposed to return zero on success and negative
error codes on failure, but it was accidentally declared as a u8 when
it needs to be an int type.

Fixes: 57e83fb9b746 ("can: hi311x: Add Holt HI-311x CAN driver")
Link: https://lore.kernel.org/r/20210729141246.GA1267@kili
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: hi3110_can_probe(): silence clang warning

This patch silences the following clang warning:

| drivers/net/can/spi/hi311x.c:874:17: warning: cast to smaller integer type
| 'enum hi3110_model' from 'const void *' [-Wvoid-pointer-to-enum-cast]
| priv->model = (enum hi3110_model)of_id->data;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fixes: 57e83fb9b746 ("can: hi311x: Add Holt HI-311x CAN driver")
Link: https://lore.kernel.org/r/20210504200520.1179635-3-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: dev: can_free_echo_skb(): extend to return can frame length

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>

can: dev: can_get_echo_skb(): extend to return can frame length

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 after queueing and after
transmission completion.

To avoid to calculate this length twice, extend can_get_echo_skb() to return
that value. Convert all users of this function, too.

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-14-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: dev: can_put_echo_skb(): extend to handle frame_len

Add a frame_len argument to can_put_echo_skb() which is used to save length of
the CAN frame into field frame_len of struct can_skb_priv so that it can be
later used after transmission completion. Convert all users of this function,
too.

Drivers which implement BQL call can_put_echo_skb() with the output of
can_skb_get_frame_len(skb) and drivers which do not simply pass zero as an
input (in the same way that NULL would be given to can_get_echo_skb()). This
way, we have a nice symmetry between the two echo functions.

Link: https://lore.kernel.org/r/20210111061335.39983-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111141930.693847-13-mkl@pengutronix.de
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

can: replace can_dlc as variable/element for payload length

The naming of can_dlc as element of struct can_frame and also as variable
name is misleading as it claims to be a 'data length CODE' but in reality
it always was a plain data length.

With the indroduction of a new 'len' element in struct can_frame we can now
remove can_dlc as name and make clear which of the former uses was a plain
length (-> 'len') or a data length code (-> 'dlc') value.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201120100444.3199-1-socketcan@hartkopp.net
[mkl: gs_usb: keep struct gs_host_frame::can_dlc as is]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: rename get_can_dlc() macro with can_cc_dlc2len()

The get_can_dlc() macro is used to ensure the payload length information of
the Classical CAN frame to be max 8 bytes (the CAN_MAX_DLEN).

Rename the macro and use the correct constant in preparation of the len/dlc
cleanup for Classical CAN frames.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/r/20201110101852.1973-3-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: Delete unnecessary checks before the macro call “dev_kfree_skb”

The dev_kfree_skb() function performs also input parameter validation.
Thus the test around the shown calls is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

can: hi311x: remove custom DMA mapped buffer

There is no need to duplicate what SPI core already does, i.e. mapping buffers
for DMA capable transfers. This patch removes all related pices of code.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

can: hi311x: Use level-triggered interrupt

If the hi3110 shares the SPI bus with another traffic-intensive device
and packets are received in high volume (by a separate machine sending
with "cangen -g 0 -i -x"), reception stops after a few minutes and the
counter in /proc/interrupts stops incrementing. Bus state is "active".
Bringing the interface down and back up reconvenes the reception. The
issue is not observed when the hi3110 is the sole device on the SPI bus.

Using a level-triggered interrupt makes the issue go away and lets the
hi3110 successfully receive 2 GByte over the course of 5 days while a
ks8851 Ethernet chip on the same SPI bus handles 6 GByte of traffic.

Unfortunately the hi3110 datasheet is mum on the trigger type. The pin
description on page 3 only specifies the polarity (active high):
http://www.holtic.com/documents/371-hi-3110_v-rev-kpdf.do

Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Akshay Bhat <akshay.bhat@timesys.com>
Cc: Casey Fitzpatrick <casey.fitzpatrick@timesys.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: Work around TX complete interrupt erratum

When sending packets as fast as possible using "cangen -g 0 -i -x", the
HI-3110 occasionally latches the interrupt pin high on completion of a
packet, but doesn't set the TXCPLT bit in the INTF register. The INTF
register contains 0x00 as if no interrupt has occurred. Even waiting
for a few milliseconds after the interrupt doesn't help.

Work around this apparent erratum by instead checking the TXMTY bit in
the STATF register ("TX FIFO empty"). We know that we've queued up a
packet for transmission if priv->tx_len is nonzero. If the TX FIFO is
empty, transmission of that packet must have completed.

Note that this is congruent with our handling of received packets, which
likewise gleans from the STATF register whether a packet is waiting in
the RX FIFO, instead of looking at the INTF register.

Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Akshay Bhat <akshay.bhat@timesys.com>
Cc: Casey Fitzpatrick <casey.fitzpatrick@timesys.com>
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Akshay Bhat <akshay.bhat@timesys.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: Acquire SPI lock on ->do_get_berr_counter

hi3110_get_berr_counter() may run concurrently to the rest of the driver
but neglects to acquire the lock protecting access to the SPI device.
As a result, it and the rest of the driver may clobber each other's tx
and rx buffers.

We became aware of this issue because transmission of packets with
"cangen -g 0 -i -x" frequently hung. It turns out that agetty executes
->do_get_berr_counter every few seconds via the following call stack:

CPU: 2 PID: 1605 Comm: agetty
[<7f3f7500>] (hi3110_get_berr_counter [hi311x])
[<7f130204>] (can_fill_info [can_dev])
[<80693bc0>] (rtnl_fill_ifinfo)
[<806949ec>] (rtnl_dump_ifinfo)
[<806b4834>] (netlink_dump)
[<806b4bc8>] (netlink_recvmsg)
[<8065f180>] (sock_recvmsg)
[<80660f90>] (___sys_recvmsg)
[<80661e7c>] (__sys_recvmsg)
[<80661ec0>] (SyS_recvmsg)
[<80108b20>] (ret_fast_syscall+0x0/0x1c)

agetty listens to netlink messages in order to update the login prompt
when IP addresses change (if /etc/issue contains \4 or \6 escape codes):
https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/commit/?id=e36deb6424e8

It's a useful feature, though it seems questionable that it causes CAN
bit error statistics to be queried.

Be that as it may, if hi3110_get_berr_counter() is invoked while a frame
is sent by hi3110_hw_tx(), bogus SPI transfers like the following may
occur:

=> 12 00 (hi3110_get_berr_counter() wanted to transmit
EC 00 to query the transmit error counter,
but the first byte was overwritten by
hi3110_hw_tx_frame())

=> EA 00 3E 80 01 FB (hi3110_hw_tx_frame() wanted to transmit a
frame, but the first byte was overwritten by
hi3110_get_berr_counter() because it wanted
to query the receive error counter)

This sequence hangs the transmission because the driver believes it has
sent a frame and waits for the interrupt signaling completion, but in
reality the chip has never sent away the frame since the commands it
received were malformed.

Fix by acquiring the SPI lock in hi3110_get_berr_counter().

I've scrutinized the entire driver for further unlocked SPI accesses but
found no others.

Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Akshay Bhat <akshay.bhat@timesys.com>
Cc: Casey Fitzpatrick <casey.fitzpatrick@timesys.com>
Cc: Stef Walter <stefw@redhat.com>
Cc: Karel Zak <kzak@redhat.com>
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Akshay Bhat <akshay.bhat@timesys.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: hi311x: Add Holt HI-311x CAN driver

This patch adds support for the Holt HI-311x CAN controller. The HI311x
CAN controller is capable of transmitting and receiving standard data
frames, extended data frames and remote frames. The HI311x interfaces
with the host over SPI.

Datasheet: www.holtic.com/documents/371-hi-3110_v-rev-jpdf.do

Signed-off-by: Akshay Bhat <nodeax@gmail.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>