As noted in commit 28c2d1a7 ("net: bcmgenet: enable loopback
during UniMAC sw_reset") the UniMAC must be clocked while sw_reset
is asserted for its state machines to reset cleanly.

The transmit and receive clocks used by the UniMAC are derived from
the signals used on its PHY interface. The bcmgenet MAC can be
configured to work with different PHY interfaces including MII,
GMII, RGMII, and Reverse MII on internal and external interfaces.
Unfortunately for the UniMAC, when configured for MII the Tx clock
is always driven from the PHY which places it outside of the direct
control of the MAC.

The earlier commit enabled a local loopback mode within the UniMAC
so that the receive clock would be derived from the transmit clock
which addressed the observed issue with an external GPHY disabling
it's Rx clock. However, when a Tx clock is not available this
loopback is insufficient.

This commit implements a workaround that leverages the fact that
the MAC can reliably generate all of its necessary clocking by
enterring the external GPHY RGMII interface mode with the UniMAC in
local loopback during the sw_reset interval. Unfortunately, this
has the undesirable side efect of the RGMII GTXCLK signal being
driven during the same window.

In most configurations this is a benign side effect as the signal
is either not routed to a pin or is already expected to drive the
pin. The one exception is when an external MII PHY is expected to
drive the same pin with its TX_CLK output creating output driver
contention.

This commit exploits the IEEE 802.3 clause 22 standard defined
isolate mode to force an external MII PHY to present a high
impedance on its TX_CLK output during the window to prevent any
contention at the pin.

The MII interface is used internally with the 40nm internal EPHY
which agressively disables its clocks for power savings leading to
incomplete resets of the UniMAC and many instabilities observed
over the years. The workaround of this commit is expected to put
an end to those problems.

Fixes: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add TLS TX counter description for the handshake retransmitted
packets that triggers the resync procedure then skip it, going
into the regular transmit flow.

Fixes: 46a3ea98 ("net/mlx5e: kTLS, Enhance TX resync flow")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The address of fw_vsc_cfg is on stack. Releasing it with devm_kfree() is
incorrect, which may result in a system crash or other security impacts.
The expected object to free is *fw_vsc_cfg.
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a couple of READ_ONCE() and WRITE_ONCE() to prevent
load-tearing and store-tearing in sock_read_timestamp()
and sock_write_timestamp()

This might prevent another KCSAN report.

Fixes: 3a0ed3e9 ("sock: Make sock->sk_stamp thread-safe")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

During the exit/unregistration process of the RmNet driver, the function
rmnet_unregister_real_device() is called to handle freeing the driver's
internal state and removing the RX handler on the underlying physical
device. However, the order of operations this function performs is wrong
and can lead to a use after free of the rmnet_port structure.

Before calling netdev_rx_handler_unregister(), this port structure is
freed with kfree(). If packets are received on any RmNet devices before
synchronize_net() completes, they will attempt to use this already-freed
port structure when processing the packet. As such, before cleaning up any
other internal state, the RX handler must be unregistered in order to
guarantee that no further packets will arrive on the device.

Fixes: ceed73a2 ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

sk_msg_trim() tries to only update curr pointer if it falls into
the trimmed region. The logic, however, does not take into the
account pointer wrapping that sk_msg_iter_var_prev() does nor
(as John points out) the fact that msg->sg is a ring buffer.

This means that when the message was trimmed completely, the new
curr pointer would have the value of MAX_MSG_FRAGS - 1, which is
neither smaller than any other value, nor would it actually be
correct.

Special case the trimming to 0 length a little bit and rework
the comparison between curr and end to take into account wrapping.

This bug caused the TLS code to not copy all of the message, if
zero copy filled in fewer sg entries than memcopy would need.

Big thanks to Alexander Potapenko for the non-KMSAN reproducer.

v2:
 - take into account that msg->sg is a ring buffer (John).

Link: https://lore.kernel.org/netdev/20191030160542.30295-1-jakub.kicinski@netronome.com/ (v1)

Fixes: d829e9c4 ("tls: convert to generic sk_msg interface")
Reported-by: syzbot+f8495bff23a879a6d0bd@syzkaller.appspotmail.com
Reported-by: syzbot+6f50c99e8f6194bf363f@syzkaller.appspotmail.com
Co-developed-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The reason for the pre-allocation of one CQE is to enable resizing of
the CQ.
Fix comment accordingly.
Signed-off-by: Dotan Barak <dotanb@dev.mellanox.co.il>
Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Vladimir Sokolovsky <vlad@mellanox.com>
Signed-off-by: Yuval Shaia <yuval.shaia@oracle.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

With the DSA core doing the call to dsa_port_disable() we do not need to
do that within the driver itself. This could cause an use after free
since past dsa_unregister_switch() we should not be accessing any
dsa_switch internal structures.

Fixes: 0394a63a ("net: dsa: enable and disable all ports")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a new filter is added to cls_api, the function
tcf_chain_tp_insert_unique() looks up the protocol/priority/chain to
determine if the tcf_proto is duplicated in the chain's hashtable. It then
creates a new entry or continues with an existing one. In cls_flower, this
allows the function fl_ht_insert_unque to determine if a filter is a
duplicate and reject appropriately, meaning that the duplicate will not be
passed to drivers via the offload hooks. However, when a tcf_proto is
destroyed it is removed from its chain before a hardware remove hook is
hit. This can lead to a race whereby the driver has not received the
remove message but duplicate flows can be accepted. This, in turn, can
lead to the offload driver receiving incorrect duplicate flows and out of
order add/delete messages.

Prevent duplicates by utilising an approach suggested by Vlad Buslov. A
hash table per block stores each unique chain/protocol/prio being
destroyed. This entry is only removed when the full destroy (and hardware
offload) has completed. If a new flow is being added with the same
identiers as a tc_proto being detroyed, then the add request is replayed
until the destroy is complete.

Fixes: 8b64678e ("net: sched: refactor tp insert/delete for concurrent execution")
Signed-off-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reported-by: Louis Peens <louis.peens@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch corrects the SPDX License Identifier style in
header files related to Hisilicon network devices. For C header files
Documentation/process/license-rules.rst mandates C-like comments
(opposed to C source files where C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since de77ecd4 ("bonding: improve link-status update in
mii-monitoring"), the bonding driver has utilized two separate variables
to indicate the next link state a particular slave should transition to.
Each is used to communicate to a different portion of the link state
change commit logic; one to the bond_miimon_commit function itself, and
another to the state transition logic.

	Unfortunately, the two variables can become unsynchronized,
resulting in incorrect link state transitions within bonding.  This can
cause slaves to become stuck in an incorrect link state until a
subsequent carrier state transition.

	The issue occurs when a special case in bond_slave_netdev_event
sets slave->link directly to BOND_LINK_FAIL.  On the next pass through
bond_miimon_inspect after the slave goes carrier up, the BOND_LINK_FAIL
case will set the proposed next state (link_new_state) to BOND_LINK_UP,
but the new_link to BOND_LINK_DOWN.  The setting of the final link state
from new_link comes after that from link_new_state, and so the slave
will end up incorrectly in _DOWN state.

	Resolve this by combining the two variables into one.
Reported-by: Aleksei Zakharov <zakharov.a.g@yandex.ru>
Reported-by: Sha Zhang <zhangsha.zhang@huawei.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Fixes: de77ecd4 ("bonding: improve link-status update in mii-monitoring")
Signed-off-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2019-11-02

The following pull-request contains BPF updates for your *net* tree.

We've added 6 non-merge commits during the last 6 day(s) which contain
a total of 8 files changed, 35 insertions(+), 9 deletions(-).

The main changes are:

1) Fix ppc BPF JIT's tail call implementation by performing a second pass
   to gather a stable JIT context before opcode emission, from Eric Dumazet.

2) Fix build of BPF samples sys_perf_event_open() usage to compiled out
   unavailable test_attr__{enabled,open} checks. Also fix potential overflows
   in bpf_map_{area_alloc,charge_init} on 32 bit archs, from Björn Töpel.

3) Fix narrow loads of bpf_sysctl context fields with offset > 0 on big endian
   archs like s390x and also improve the test coverage, from Ilya Leoshkevich.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Don't swap oper and admin schedules too early, it's not correct and
causes crash.

Steps to reproduce:

1)
tc qdisc replace dev eth0 parent root handle 100 taprio \
    num_tc 3 \
    map 2 2 1 0 2 2 2 2 2 2 2 2 2 2 2 2 \
    queues 1@0 1@1 1@2 \
    base-time $SOME_BASE_TIME \
    sched-entry S 01 80000 \
    sched-entry S 02 15000 \
    sched-entry S 04 40000 \
    flags 2

2)
tc qdisc replace dev eth0 parent root handle 100 taprio \
    base-time $SOME_BASE_TIME \
    sched-entry S 01 90000 \
    sched-entry S 02 20000 \
    sched-entry S 04 40000 \
    flags 2

3)
tc qdisc replace dev eth0 parent root handle 100 taprio \
    base-time $SOME_BASE_TIME \
    sched-entry S 01 150000 \
    sched-entry S 02 200000 \
    sched-entry S 04 40000 \
    flags 2

Do 2 3 2 .. steps  more times if not happens and observe:

[  305.832319] Unable to handle kernel write to read-only memory at
virtual address ffff0000087ce7f0
[  305.910887] CPU: 0 PID: 0 Comm: swapper/0 Not tainted
[  305.919306] Hardware name: Texas Instruments AM654 Base Board (DT)

[...]

[  306.017119] x1 : ffff800848031d88 x0 : ffff800848031d80
[  306.022422] Call trace:
[  306.024866]  taprio_free_sched_cb+0x4c/0x98
[  306.029040]  rcu_process_callbacks+0x25c/0x410
[  306.033476]  __do_softirq+0x10c/0x208
[  306.037132]  irq_exit+0xb8/0xc8
[  306.040267]  __handle_domain_irq+0x64/0xb8
[  306.044352]  gic_handle_irq+0x7c/0x178
[  306.048092]  el1_irq+0xb0/0x128
[  306.051227]  arch_cpu_idle+0x10/0x18
[  306.054795]  do_idle+0x120/0x138
[  306.058015]  cpu_startup_entry+0x20/0x28
[  306.061931]  rest_init+0xcc/0xd8
[  306.065154]  start_kernel+0x3bc/0x3e4
[  306.068810] Code: f2fbd5b7 f2fbd5b6 d503201f f9400422 (f9000662)
[  306.074900] ---[ end trace 96c8e2284a9d9d6e ]---
[  306.079507] Kernel panic - not syncing: Fatal exception in interrupt
[  306.085847] SMP: stopping secondary CPUs
[  306.089765] Kernel Offset: disabled

Try to explain one of the possible crash cases:

The "real" admin list is assigned when admin_sched is set to
new_admin, it happens after "swap", that assigns to oper_sched NULL.
Thus if call qdisc show it can crash.

Farther, next second time, when sched list is updated, the admin_sched
is not NULL and becomes the oper_sched, previous oper_sched was NULL so
just skipped. But then admin_sched is assigned new_admin, but schedules
to free previous assigned admin_sched (that already became oper_sched).

Farther, next third time, when sched list is updated,
while one more swap, oper_sched is not null, but it was happy to be
freed already (while prev. admin update), so while try to free
oper_sched the kernel panic happens at taprio_free_sched_cb().

So, move the "swap emulation" where it should be according to function
comment from code.

Fixes: 9c66d156 ("taprio: Add support for hardware offloading")
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'linux-can-fixes-for-5.4-20191105' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2019-11-05

this is a pull request of 33 patches for net/master.

In the first patch Wen Yang's patch adds a missing of_node_put() to CAN device
infrastructure.

Navid Emamdoost's patch for the gs_usb driver fixes a memory leak in the
gs_can_open() error path.

Johan Hovold provides two patches, one for the mcba_usb, the other for the
usb_8dev driver. Both fix a use-after-free after USB-disconnect.

Joakim Zhang's patch improves the flexcan driver, the ECC mechanism is now
completely disabled instead of masking the interrupts.

The next three patches all target the peak_usb driver. Stephane Grosjean's
patch fixes a potential out-of-sync while decoding packets, Johan Hovold's
patch fixes a slab info leak, Jeroen Hofstee's patch adds missing reporting of
bus off recovery events.

Followed by three patches for the c_can driver. Kurt Van Dijck's patch fixes
detection of potential missing status IRQs, Jeroen Hofstee's patches add a chip
reset on open and add missing reporting of bus off recovery events.

Appana Durga Kedareswara rao's patch for the xilinx driver fixes the flags
field initialization for axi CAN.

The next seven patches target the rx-offload helper, they are by me and Jeroen
Hofstee. The error handling in case of a queue overflow is fixed removing a
memory leak. Further the error handling in case of queue overflow and skb OOM
is cleaned up.

The next two patches are by me and target the flexcan and ti_hecc driver. In
case of a error during can_rx_offload_queue_sorted() the error counters in the
drivers are incremented.

Jeroen Hofstee provides 6 patches for the ti_hecc driver, which properly stop
the device in ifdown, improve the rx-offload support (which hit mainline in
v5.4-rc1), and add missing FIFO overflow and state change reporting.

The following four patches target the j1939 protocol. Colin Ian King's patch
fixes a memory leak in the j1939_sk_errqueue() handling. Three patches by
Oleksij Rempel fix a memory leak on socket release and fix the EOMA packet in
the transport protocol.

Timo Schlüßler's patch fixes a potential race condition in the mcp251x driver
on after suspend.

The last patch is by Yegor Yefremov and updates the SPDX-License-Identifier to
v3.0.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The "GPL-2.0" license identifier changed to "GPL-2.0-only" in SPDX v3.0.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

In mcp251x_restart_work_handler() the variable to stop the interrupt
handler (priv->force_quit) is reset after the chip is restarted and thus
a interrupt might occur.

This patch fixes the potential race condition by resetting force_quit
before enabling interrupts.
Signed-off-by: Timo Schlüßler <schluessler@krause.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

We were sending malformed EOMA with total message size set to 0. This
issue has been fixed in the previous patch.

In this patch a sanity check is added to the RX path and a error message
is displayed.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: j1939: transport: j1939_session_fresh_new(): make sure EOMA is send with the total message size set

We were sending malformed EOMA messageswith total message size set to 0.

This patch fixes the bug.

Reported-by: https://github.com/linux-can/can-utils/issues/159Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Filters array is coped from user space and linked to the j1939 socket.
On socket release this memory was not freed.

Fixes: 9d71dd0c ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Currently the error return paths do not free skb and this results in a
memory leak. Fix this by freeing them before the return.

Addresses-Coverity: ("Resource leak")
Fixes: 9d71dd0c ("can: add support of SAE J1939 protocol")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

While the ti_hecc has interrupts to report when the error counters increase
to a certain level and which change state it doesn't handle the case that
the error counters go down again, so the reported state can actually be
wrong. Since there is no interrupt for that, do update state based on the
error counters, when the state is not error active and goes down again.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The HECC_CANES register handles the flags specially, it only updates
the flags after a one is written to them. Since the interrupt for
frame errors is not enabled an old error can hence been seen when a
state interrupt arrives. For example if the device is not connected
to the CAN-bus the error warning interrupt will have HECC_CANES
indicating there is no ack. The error passive interrupt thereafter
will have HECC_CANES flagging that there is a warning level. And if
thereafter there is a message successfully send HECC_CANES points to
an error passive event, while in reality it became error warning
again. In summary, the state is not always reported correctly.

So handle the state changes and frame errors separately. The state
changes are now based on the interrupt flags and handled directly
when they occur. The reporting of the frame errors is still done as
before, as a side effect of another interrupt.

note: the hecc_clear_bit will do a read, modify, write. So it will
not only clear the bit, but also reset all other bits being set as
a side affect, hence it is replaced with only clearing the flags.

note: The HECC_CANMC_CCR is no longer cleared in the state change
interrupt, it is completely unrelated.

And use net_ratelimit to make checkpatch happy.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

When the rx FIFO overflows the ti_hecc would silently drop them since
the overwrite protection is enabled for all mailboxes. So disable it for
the lowest priority mailbox and return a proper error value when receive
message lost is set. Drop the message itself in that case, since it
might be partially updated.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Acked-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Release the mailbox after reading it, so it can be reused a bit earlier.
Since "can: rx-offload: continue on error" all pending message bits are
cleared directly, so remove clearing them in ti_hecc.
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The HECC_CANMIM is set in the xmit path and cleared in the interrupt.
Since this is done with a read, modify, write action the register might
end up with some more MIM enabled then intended, since it is not
protected. That doesn't matter at all, since the tx interrupt disables
the mailbox with HECC_CANME (while holding a spinlock). So lets just
always keep MIM set.

While at it, since the mailbox direction never changes, don't set it
every time a message is send, ti_hecc_reset() already sets them to tx.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

When the interface goes down, the CPK should no longer take an active
part in the CAN-bus communication, like sending acks and error frames.
So enable configuration mode in ti_hecc_stop, so the CPK is no longer
active.

When a transceiver switch is present the acks and errors don't make it
to the bus, but disabling the CPK then does prevent oddities, like
ti_hecc_reset() failing, since the CPK can become bus-off and starts
counting the 11 bit recessive bits, which seems to block the reset. It
can also cause invalid interrupts and disrupt the CAN-bus, since
transmission can be stopped in the middle of a message, by disabling the
tranceiver while the CPK is sending.

Since the CPK is disabled after normal power on, it is typically only
seen when the interface is restarted.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: ti_hecc: ti_hecc_error(): increase error counters if skb enqueueing via can_rx_offload_queue_sorted() fails

The call to can_rx_offload_queue_sorted() may fail and return an error
(in the current implementation due to resource shortage). The passed skb
is consumed.

This patch adds incrementing of the appropriate error counters to let
the device statistics reflect that there's a problem.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The call to can_rx_offload_queue_sorted() may fail and return an error
(in the current implementation due to resource shortage). The passed skb
is consumed.

This patch adds incrementing of the appropriate error counters to let
the device statistics reflect that there's a problem.
Reported-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

In case of a resource shortage, i.e. the rx_offload queue will overflow
or a skb fails to be allocated (due to OOM),
can_rx_offload_offload_one() will call mailbox_read() to discard the
mailbox and return an ERR_PTR.

If the hardware FIFO is empty can_rx_offload_offload_one() will return
NULL.

In case a CAN frame was read from the hardware,
can_rx_offload_offload_one() returns the skb containing it.

Without this patch can_rx_offload_irq_offload_fifo() bails out if no skb
returned, regardless of the reason.

Similar to can_rx_offload_irq_offload_timestamp() in case of a resource
shortage the whole FIFO should be discarded, to avoid an IRQ storm and
give the system some time to recover. However if the FIFO is empty the
loop can be left.

With this patch the loop is left in case of empty FIFO, but not on
errors.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

In case of a resource shortage, i.e. the rx_offload queue will overflow
or a skb fails to be allocated (due to OOM),
can_rx_offload_offload_one() will call mailbox_read() to discard the
mailbox and return an ERR_PTR.

However can_rx_offload_irq_offload_timestamp() bails out in the error
case. In case of a resource shortage all mailboxes should be discarded,
to avoid an IRQ storm and give the system some time to recover.

Since can_rx_offload_irq_offload_timestamp() is typically called from a
while loop, all message will eventually be discarded. So let's continue
on error instead to discard them directly.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: rx-offload: can_rx_offload_offload_one(): use ERR_PTR() to propagate error value in case of errors

Before this patch can_rx_offload_offload_one() returns a pointer to a
skb containing the read CAN frame or a NULL pointer.

However the meaning of the NULL pointer is ambiguous, it can either mean
the requested mailbox is empty or there was an error.

This patch fixes this situation by returning:
- pointer to skb on success
- NULL pointer if mailbox is empty
- ERR_PTR() in case of an error

All users of can_rx_offload_offload_one() have been adopted, no
functional change intended.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

If the rx-offload skb_queue is full or the skb allocation fails (due to OOM),
the mailbox contents is discarded.

This patch adds the incrementing of the rx_fifo_errors statistics counter.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: rx-offload: can_rx_offload_offload_one(): do not increase the skb_queue beyond skb_queue_len_max

The skb_queue is a linked list, holding the skb to be processed in the
next NAPI call.

Without this patch, the queue length in can_rx_offload_offload_one() is
limited to skb_queue_len_max + 1. As the skb_queue is a linked list, no
array or other resources are accessed out-of-bound, however this
behaviour is counterintuitive.

This patch limits the rx-offload skb_queue length to skb_queue_len_max.

Fixes: d254586c ("can: rx-offload: Add support for HW fifo based irq offloading")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

If the rx-offload skb_queue is full can_rx_offload_queue_tail() will not
queue the skb and return with an error.

This patch frees the skb in case of a full queue, which brings
can_rx_offload_queue_tail() in line with the
can_rx_offload_queue_sorted() function, which has been adjusted in the
previous patch.

The return value is adjusted to -ENOBUFS to better reflect the actual
problem.

The device stats handling is left to the caller.

Fixes: d254586c ("can: rx-offload: Add support for HW fifo based irq offloading")
Reported-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

If the rx-offload skb_queue is full can_rx_offload_queue_sorted() will
not queue the skb and return with an error.

None of the callers of this function, issue a kfree_skb() to free the
not queued skb. This results in a memory leak.

This patch fixes the problem by freeing the skb in case of a full queue.
The return value is adjusted to -ENOBUFS to better reflect the actual
problem.

The device stats handling is left to the callers, as this function might
be used in both the rx and tx path.

Fixes: 55059f2b ("can: rx-offload: introduce can_rx_offload_get_echo_skb() and can_rx_offload_queue_sorted() functions")
Cc: linux-stable <stable@vger.kernel.org>
Cc: Martin Hundebøll <martin@geanix.com>
Reported-by: Martin Hundebøll <martin@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

AXI CANIP doesn't support tx fifo empty interrupt feature(TXFEMP),
update the flags filed in the driver for AXI CAN case accordingly.

Fixes: 3281b380 ("can: xilinx_can: Fix flags field initialization for axi can and canps")
Reported-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

While the state is updated when the error counters increase and
decrease, there is no event when the bus recovers and the error counters
decrease again. So add that event as well.

Change the state going downward to be ERROR_PASSIVE -> ERROR_WARNING ->
ERROR_ACTIVE instead of directly to ERROR_ACTIVE again.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Acked-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Tested-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

When the CAN interface is closed it the hardwre is put in power down
mode, but does not reset the error counters / state. Reset the D_CAN on
open, so the reported state and the actual state match.

According to [1], the C_CAN module doesn't have the software reset.

[1] http://www.bosch-semiconductors.com/media/ip_modules/pdf_2/c_can_fd8/users_manual_c_can_fd8_r210_1.pdfSigned-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

When the status register is read without the status IRQ pending, the
chip may not raise the interrupt line for an upcoming status interrupt
and the driver may miss a status interrupt.

It is critical that the BUSOFF status interrupt is forwarded to the
higher layers, since no more interrupts will follow without
intervention.

Thanks to Wolfgang and Joe for bringing up the first idea.
Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Joe Burmeister <joe.burmeister@devtank.co.uk>
Fixes: fa39b54c ("can: c_can: Get rid of pointless interrupts")
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

While the state changes are reported when the error counters increase
and decrease, there is no event when the bus recovers and the error
counters decrease again. So add those as well.

Change the state going downward to be ERROR_PASSIVE -> ERROR_WARNING ->
ERROR_ACTIVE instead of directly to ERROR_ACTIVE again.
Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Cc: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>