Removing initialization of nrxq and rxq_size in uld_info. As
ipsec uses nic queues only, there is no need to create uld
rx queues for ipsec.
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Link: https://lore.kernel.org/r/20210113044302.25522-1-ayush.sawal@chelsio.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Alex Elder says:

====================
net: ipa: GSI interrupt updates

This series implements some updates for the GSI interrupt code,
buliding on some bug fixes implemented last month.

The first two are simple changes made to improve readability and
consistency.  The third replaces all msleep() calls with comparable
usleep_range() calls.

The remainder make some more substantive changes to make the code
align with recommendations from Qualcomm.  The fourth implements a
much shorter timeout for completion GSI commands, and the fifth
implements a longer delay between retries of the STOP channel
command.  Finally, the last implements retries for stopping TX
channels (in addition to RX channels).
====================

Link: https://lore.kernel.org/r/20210113171532.19248-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

For RX channels we issue a stop command more than once if necessary
to allow it to stop.  It turns out that TX channels could also
require retries.

Retry channel stop commands if necessary regardless of the channel
direction.  Rename the symbol defining the retry count so it's not
RX-specific.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

If a GSI stop channel command leaves the channel in STOP_IN_PROC
state, we retry the stop command after a 1-2 millisecond delay.

I have been told that a 3-5 millisecond delay is a better choice.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The GSI command timeout is currently 5 seconds, which is much higher
than it should be.

Express the timeout in milliseconds rather than seconds, and reduce
it to 50 milliseconds.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

65;6003;1c
The use of msleep() for small periods (less than 20 milliseconds) is
not recommended because the actual delay can be much different than
expected.

We use msleep(1) in several places in the IPA driver to insert short
delays.  Replace them with usleep_range calls, which should reliably
delay a period in the range requested.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Create a new function gsi_irq_ev_ctrl_enable() that encapsulates
enabling the event ring control GSI interrupt type, and enables a
single event ring to signal that interrupt.  When an event ring
changes state as a result of an event ring command, it triggers this
interrupt.

Create an inverse function gsi_irq_ev_ctrl_disable() as well.
Because only one event ring at a time is enabled for this interrupt,
we can simply disable the interrupt for *all* channels.

Create a pair of helpers that serve the same purpose for channel
commands.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The return value of gsi_command() is true if successful or false if
we time out waiting for a completion interrupt.

Rename the variables in the three callers of gsi_command() to be
"timeout", to make it more obvious that's the only reason for
failure.

In addition, add a "gsi_" prefix to evt_ring_command() so its name
is consistent with the convention used for GSI channel and generic
commands.
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Merge tag 'linux-can-next-for-5.12-20210114' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2021-01-14

The first two patches update the MAINTAINERS file, Lukas Bulwahn's patch fixes
the files entry for the tcan4x5x driver, which was broken by me in net-next.
A patch by me adds the a missing header file to the CAN Networking Layer.

The next 5 patches are by me and split the the CAN driver related
infrastructure code into more files in a separate subdir. The next two patches
by me clean up the CAN length related code. This is followed by 6 patches by
Vincent Mailhol and me, they add helper code for for CAN frame length
calculation neede for BQL support.

A patch by Vincent Mailhol adds software TX timestamp support.

The last patch is by me, targets the tcan4x5x driver, and removes the unneeded
__packed attribute from the struct tcan4x5x_map_buf.

* tag 'linux-can-next-for-5.12-20210114' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next:
  can: tcan4x5x: remove __packed attribute from struct tcan4x5x_map_buf
  can: dev: can_put_echo_skb(): add software tx timestamps
  can: dev: can_rx_offload_get_echo_skb(): extend to return can frame length
  can: dev: can_get_echo_skb(): extend to return can frame length
  can: dev: can_put_echo_skb(): extend to handle frame_len
  can: dev: extend struct can_skb_priv to hold CAN frame length
  can: length: can_skb_get_frame_len(): introduce function to get data length of frame in data link layer
  can: length: canfd_sanitize_len(): add function to sanitize CAN-FD data length
  can: length: can_fd_len2dlc(): simplify length calculcation
  can: length: convert to kernel coding style
  can: dev: move netlink related code into seperate file
  can: dev: move skb related into seperate file
  can: dev: move length related code into seperate file
  can: dev: move bittiming related code into seperate file
  can: dev: move driver related infrastructure into separate subdir
  MAINTAINERS: CAN network layer: add missing header file can-ml.h
  MAINTAINERS: adjust entry to tcan4x5x file split
====================

Link: https://lore.kernel.org/r/20210114075617.1402597-1-mkl@pengutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Tobias Waldekranz says:

====================
net: dsa: Link aggregation support

Start of by adding an extra notification when adding a port to a bond,
this allows static LAGs to be offloaded using the bonding driver.

Then add the generic support required to offload link aggregates to
drivers built on top of the DSA subsystem.

Finally, implement offloading for the mv88e6xxx driver, i.e. Marvell's
LinkStreet family.

Supported LAG implementations:
- Bonding
- Team

Supported modes:
- Isolated. The LAG may be used as a regular interface outside of any
  bridge.
- Bridged. The LAG may be added to a bridge, in which case switching
  is offloaded between the LAG and any other switch ports. I.e. the
  LAG behaves just like a port from this perspective.

In bridged mode, the following is supported:
- STP filtering.
- VLAN filtering.
- Multicast filtering. The bridge correctly snoops IGMP and configures
  the proper groups if snooping is enabled. Static groups can also be
  configured. MLD seems to work, but has not been extensively tested.
- Unicast filtering. Automatic learning works. Static entries are
  _not_ supported. This will be added in a later series as it requires
  some more general refactoring in mv88e6xxx before I can test it.

v4 -> v5:
- Cleanup PVT configuration for LAGed ports in mv88e6xxx (Vladimir)
- Document dsa_lag_{map,unmap} (Vladimir)
====================

Link: https://lore.kernel.org/r/20210113084255.22675-1-tobias@waldekranz.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Packets ingressing on a LAG that egress on the CPU port, which are not
classified as management, will have a FORWARD tag that does not
contain the normal source device/port tuple. Instead the trunk bit
will be set, and the port field holds the LAG id.

Since the exact source port information is not available in the tag,
frames are injected directly on the LAG interface and thus do never
pass through any DSA port interface on ingress.

Management frames (TO_CPU) are not affected and will pass through the
DSA port interface as usual.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Support offloading of LAGs to hardware. LAGs may be attached to a
bridge in which case VLANs, multicast groups, etc. are also offloaded
as usual.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Monitor the following events and notify the driver when:

- A DSA port joins/leaves a LAG.
- A LAG, made up of DSA ports, joins/leaves a bridge.
- A DSA port in a LAG is enabled/disabled (enabled meaning
  "distributing" in 802.3ad LACP terms).

When a LAG joins a bridge, the DSA subsystem will treat that as each
individual port joining the bridge. The driver may look at the port's
LAG device pointer to see if it is associated with any LAG, if that is
required. This is analogue to how switchdev events are replicated out
to all lower devices when reaching e.g. a LAG.

Drivers can optionally request that DSA maintain a linear mapping from
a LAG ID to the corresponding netdev by setting ds->num_lag_ids to the
desired size.

In the event that the hardware is not capable of offloading a
particular LAG for any reason (the typical case being use of exotic
modes like broadcast), DSA will take a hands-off approach, allowing
the LAG to be formed as a pure software construct. This is reported
back through the extended ACK, but is otherwise transparent to the
user.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In a situation where a standalone port is indirectly attached to a
bridge (e.g. via a LAG) which is not offloaded, do not offload any
port attributes either. The port should behave as a standard NIC.

Previously, on mv88e6xxx, this meant that in the following setup:

     br0
     /
  team0
   / \
swp0 swp1

If vlan filtering was enabled on br0, swp0's and swp1's QMode was set
to "secure". This caused all untagged packets to be dropped, as their
default VID (0) was not loaded into the VTU.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When creating a static bond (e.g. balance-xor), all ports will always
be enabled. This is set, and the corresponding notification is sent
out, before the port is linked to the bond upper.

In the offloaded case, this ordering is hard to deal with.

The lower will first see a notification that it can not associate with
any bond. Then the bond is joined. After that point no more
notifications are sent, so all ports remain disabled.

This change simply sends an extra notification once the port has been
linked to the upper to synchronize the initial state.
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The wrappers in include/linux/pci-dma-compat.h should go away.

The patch has been generated with the coccinelle script below and has been
hand modified to replace GFP_ with a correct flag.
It has been compile tested.

When memory is allocated in 'mlxsw_pci_queue_init()' and
'mlxsw_pci_fw_area_init()' GFP_KERNEL can be used because both functions
are already using this flag and no lock is acquired.

When memory is allocated in 'mlxsw_pci_mbox_alloc()' GFP_KERNEL can be used
because it is only called from the probe function and no lock is acquired
in the between.
The call chain is:
  --> mlxsw_pci_probe()
    --> mlxsw_pci_cmd_init()
      --> mlxsw_pci_mbox_alloc()

While at it, also replace the 'dma_set_mask/dma_set_coherent_mask' sequence
by a less verbose 'dma_set_mask_and_coherent() call.

@@
@@
-    PCI_DMA_BIDIRECTIONAL
+    DMA_BIDIRECTIONAL

@@
@@
-    PCI_DMA_TODEVICE
+    DMA_TO_DEVICE

@@
@@
-    PCI_DMA_FROMDEVICE
+    DMA_FROM_DEVICE

@@
@@
-    PCI_DMA_NONE
+    DMA_NONE

@@
expression e1, e2, e3;
@@
-    pci_alloc_consistent(e1, e2, e3)
+    dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3;
@@
-    pci_zalloc_consistent(e1, e2, e3)
+    dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3, e4;
@@
-    pci_free_consistent(e1, e2, e3, e4)
+    dma_free_coherent(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_map_single(e1, e2, e3, e4)
+    dma_map_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_single(e1, e2, e3, e4)
+    dma_unmap_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4, e5;
@@
-    pci_map_page(e1, e2, e3, e4, e5)
+    dma_map_page(&e1->dev, e2, e3, e4, e5)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_page(e1, e2, e3, e4)
+    dma_unmap_page(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_map_sg(e1, e2, e3, e4)
+    dma_map_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_sg(e1, e2, e3, e4)
+    dma_unmap_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_single_for_cpu(e1, e2, e3, e4)
+    dma_sync_single_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_single_for_device(e1, e2, e3, e4)
+    dma_sync_single_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_sg_for_cpu(e1, e2, e3, e4)
+    dma_sync_sg_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_sg_for_device(e1, e2, e3, e4)
+    dma_sync_sg_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2;
@@
-    pci_dma_mapping_error(e1, e2)
+    dma_mapping_error(&e1->dev, e2)

@@
expression e1, e2;
@@
-    pci_set_dma_mask(e1, e2)
+    dma_set_mask(&e1->dev, e2)

@@
expression e1, e2;
@@
-    pci_set_consistent_dma_mask(e1, e2)
+    dma_set_coherent_mask(&e1->dev, e2)
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20210114084757.490540-1-christophe.jaillet@wanadoo.frSigned-off-by: Jakub Kicinski <kuba@kernel.org>

prestera_bridge_port_vlan_add should have been called with vlan->vid,
however this was masked by the presence of the local vid variable and I
did not notice the build warning.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: b7a9e0da ("net: switchdev: remove vid_begin -> vid_end range from VLAN objects")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Taras Chornyi <tchornyi@marvell.com>
Link: https://lore.kernel.org/r/20210114083556.2274440-1-olteanv@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

As requested by upstream OVS, added some error messages in the
validate_and_copy_dec_ttl function.

Includes a small cleanup, which removes an unnecessary parameter
from the dec_ttl_exception_handler() function.
Reported-by: Flavio Leitner <fbl@sysclose.org>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Link: https://lore.kernel.org/r/161054576573.26637.18396634650212670580.stgit@ebuildSigned-off-by: Jakub Kicinski <kuba@kernel.org>

David Ahern says:

====================
selftests: Updates to allow single instance of nettest for client and server

Update nettest to handle namespace change internally to allow a
single instance to run both client and server modes. Device validation
needs to be moved after the namespace change and a few run time
options need to be split to allow values for client and server.

v4
- really fix the memory leak with stdout/stderr buffers

v3
- send proper status in do_server for UDP sockets
- fix memory leak with stdout/stderr buffers
- new patch with separate option for address binding
- new patch to remove unnecessary newline

v2
- fix checkpath warnings
====================

Link: https://lore.kernel.org/r/20210114030949.54425-1-dsahern@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add separate option to nettest to specify local address
binding in client mode.
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add new options to nettest to specify device binding and expected
device binding for server mode, and update fcnal-test script. This
is needed to allow a single instance of nettest running both server
and client modes to use different device bindings.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add new option to nettest to specify MD5 password to use for client
side. Update fcnal-test script. This is needed for a single instance
running both server and client modes to test password mismatches.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

nettest started with -r as the remote address for MD5 passwords.
The -m argument was added to use prefixes with a length when that
feature was added to the kernel. Since -r is used to specify
remote address for client mode, change nettest to only use -m
for MD5 passwords and update fcnal-test script.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When a single instance of nettest is used for client and server
make sure address validation is only done for client mode.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

A few logging lines are missing the newline, or need it moved up for
cleaner logging.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When a single instance of nettest is doing both client and
server modes, stdout and stderr messages can get interlaced
and become unreadable. Allocate a new set of buffers for the
child process handling server mode.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add option to nettest to run both client and server within a
single instance. Client forks a child process to run the server
code. A pipe is used for the server to tell the client it has
initialized and is ready or had an error. This avoid unnecessary
sleeps to handle such race when the commands are separately launched.
Signed-off-by: Seth David Schoen <schoen@loyalty.org>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add options to specify server and client network namespace to
use before running respective functions.
Signed-off-by: Seth David Schoen <schoen@loyalty.org>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

IPv6 addresses can have a device name to declare a scope (e.g.,
fe80::5054:ff:fe12:3456%eth0). The next patch adds support to
switch network namespace before running client or server code
(or both), so move the address validation to the server and
client functions.

IPv4 multicast groups do not have the device scope in the address
specification, so they can be validated inline with option parsing.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

convert_addr needs to be invoked in a different location. Move
the code up to avoid a forward declaration.

Code move only.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Later patch adds support for switching network namespaces before
running client, server or both. Device validations need to be
done after the network namespace switch, so add a helper to do it
and invoke in server and client code versus inline with argument
parsing. Move related argument checks as well.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Bjarni Jonasson says:

====================
Add 100 base-x mode

Adding support for 100 base-x in phylink.
The Sparx5 switch supports 100 base-x pcs (IEEE 802.3 Clause 24) 4b5b encoded.
These patches adds phylink support for that mode.

Tested in Sparx5, using sfp modules:
Axcen 100fx AXFE-1314-0521 (base-fx)
Axcen 100lx AXFE-1314-0551 (base-lx)
HP SFP 100FX J9054C (bx-10)
Excom SFP-SX-M1002 (base-lx)

v1 -> v2:
  Added description to Documentation/networking/phy.rst
  Moved PHY_INTERFACE_MODE_100BASEX to above 1000BASEX
  Patching against net-next
====================

Link: https://lore.kernel.org/r/20210113115626.17381-1-bjarni.jonasson@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Add support for 100Base-FX, 100Base-LX, 100Base-PX and 100Base-BX10 modules
This is needed for Sparx-5 switch.
Signed-off-by: Bjarni Jonasson <bjarni.jonasson@microchip.com>
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Sparx-5 supports this mode and it is missing in the PHY core.
Signed-off-by: Bjarni Jonasson <bjarni.jonasson@microchip.com>
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This bit is enabled by default and advertises support for extended
next page support.  XNP is only needed for 10GBase-T and MultiGig
support which is not supported. Additionally, Cisco MultiGig switches
will read this bit and attempt 10Gb negotiation even though Next Page
support is disabled. This will cause timeouts when the interface is
forced to 100Mbps and auto-negotiation will fail. The interfaces are
only 1000Base-T and supporting auto-negotiation for this only requires
the Next Page bit to be set.

Taken from:
https://github.com/SolidRun/linux-stable/commit/7406c5244b7ea6bc17a2afe8568277a8c4b126a9
and adapted to mainline kernels by rmk.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/E1kzSdb-000417-FJ@rmk-PC.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The first member of struct tcan4x5x_map_buf is the struct tcan4x5x_buf_cmd,
which has a size of 4 bytes. It's followed by an array of u8. The compiler
places the array directly after the struct tcan4x5x_buf_cmd.

This patch removes the not needed attribute __packed from the struct
tcan4x5x_map_buf.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20210113203955.912916-1-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Call skb_tx_timestamp() within can_put_echo_skb() so that a software tx
timestamp gets attached to the skb.

There two main reasons to include this call in can_put_echo_skb():

  * It easily allow to enable the tx timestamp on all devices with
    just one small change.

  * According to Documentation/networking/timestamping.rst, the tx
    timestamps should be generated in the device driver as close as possible,
    but always prior to passing the packet to the network interface. During the
    call to can_put_echo_skb(), the skb gets cloned meaning that the driver
    should not dereference the skb variable anymore after can_put_echo_skb()
    returns. This makes can_put_echo_skb() the very last place we can use the
    skb without having to access the echo_skb[] array.

Remark: by default, skb_tx_timestamp() does nothing. It needs to be activated
by passing the SOF_TIMESTAMPING_TX_SOFTWARE flag either through socket options
or control messages.

References:

 * Support for the error queue in CAN RAW sockets (which is needed for
   tx timestamps) was introduced in:
   https://git.kernel.org//torvalds/c/eb88531bdbfaafb827192d1fc6c5a3fcc4fadd96

  * Put the call to skb_tx_timestamp() just before adding it to the
    array:
    https://lore.kernel.org/r/043c3ea1-6bdd-59c0-0269-27b2b5b36cec@victronenergy.com

  * About Tx hardware timestamps
    https://lore.kernel.org/r/20210111171152.GB11715@hoboy.vegasvil.orgSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210112095437.6488-2-mailhol.vincent@wanadoo.frSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

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_rx_offload_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/20210111141930.693847-15-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

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