Add support for Xilinx CAN FD core.

The major difference from the previously supported cores is that there
are TX mailboxes instead of a TX FIFO and the RX FIFO access method is
different.

We only transmit one frame at a time to prevent the HW from reordering
frames (it uses CAN ID priority order).

Support for CAN FD protocol is not added yet.

v2: Removed unnecessary "rx-mode" DT property and wrapped some long
    lines.
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Xilinx CAN FD cores are different enough from the previous Zynq and AXI
CAN cores that some refactoring of the driver is needed.

This commit contains most of the required refactoring to existing code
and should not alter behavior on existing supported HW.

The changes are:

- Reading and writing to frame registers is parametrized to allow
  reading/writing a different frame in the future.

- Slightly misleading (as it did not specify *all* the interrupts
  supported by the HW) XCAN_INTR_ALL is replaced with specifying the
  interrupts inline in interrupt enabling code.

- xcan_devtype_data.caps is renamed to xcan_devtype_data.flags to allow
  for flags that define alternative functionality (e.g. mailboxes vs.
  FIFO) instead of purely additive capabilities.

- can_bittiming_const is added to xcan_devtype_data as CAN FD cores will
  have wider setting ranges.

- bus_clk clock name is now determined through xcan_devtype_data instead
  of comparing compatible string in probe().

- xcan_devtype_data is added to xcan_priv to allow flag checks after
  probe().

- XCAN_CAP_WATERMARK is now XCAN_FLAG_TXFEMP. CAN FD cores have
  watermark support but no TXFEMP interrupt, which is what we are
  actually interested in.

- xcan_start_xmit() is split to in two parts to prepare for TX mailboxes
  instead of FIFO in CAN FD cores.

v2: Wrapped some long lines in xcan_write_frame().
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Add compatible string and new attributes to support the Xilinx CAN FD
core.

Unlike the previously documented Xilinx CAN cores, the CAN FD core has
TX mailboxes instead of TX FIFO, and optionally RX mailboxes instead of
RX FIFO (selected at core generation time, not switchable at runtime).
Add "tx-mailbox-count" and "rx-mailbox-count" to specify the mailbox
counts instead of reusing "tx-fifo-depth" and "rx-fifo-depth".

The RX FIFO depth is constant 32, but allow it to be specified via
"rx-fifo-depth" to match DT usage with Zynq CAN (which has constant RX
FIFO of depth of 64).

v2: Remove unnecessary "rx-mode" DT property.
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Cc: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The driver updates stats.tx_bytes in start_xmit() even though it could
do so in TX interrupt handler.

Change the code to update tx_bytes in the interrupt handler, using the
return value of can_get_echo_skb().
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Replace some custom code with a call to can_change_state().

This subtly changes the error reporting behavior when both RX and TX
error counters indicate the same state.

Previously, if both RX and TX counters indicated the same state:
- if overall state is PASSIVE, report CAN_ERR_CRTL_RX_PASSIVE
- if overall state is WARNING, report CAN_ERR_CRTL_TX_WARNING or
  CAN_ERR_CRTL_RX_WARNING depending on which counter is higher,
  or CAN_ERR_CRTL_RX_WARNING if the counters have the same value.

After this commit:
- report RX_* or TX_* depending on which counter is higher, or both if
  the counters have exactly the same value.

This behavior is consistent with many other CAN drivers that use this
same code pattern.

Tested with the integrated CAN on Zynq-7000 SoC.

v2: Simplify resolving states as suggested by Andri Yngvason.
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The xilinx_can driver currently increments error-warning and
error-passive statistics on every error interrupt regardless of whether
the interface was already in the same state. Similarly, the error frame
sent on error interrupts is always sent with
CAN_ERR_CRTL_(RX|TX)_(PASSIVE|WARNING) bit set.

To make the error-warning and error-passive statistics more useful, add
a check to only set the error state when the state has actually been
changed.

Tested with the integrated CAN on Zynq-7000 SoC.
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

pcan_add_channels() is never called in atomic context.

pcan_add_channels() is only called by pcan_probe(), which is only set as
".probe" in struct pcmcia_driver.

Despite never getting called from atomic context, pcan_add_channels()
calls mdelay() to busily wait.
This is not necessary and can be replaced with usleep_range() to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

peak_pci_probe() is never called in atomic context.

peak_pci_probe() is set as ".probe" in struct pci_driver.

Despite never getting called from atomic context, peak_pci_probe()
calls mdelay() to busily wait.
This is not necessary and can be replaced with usleep_range() to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The existing SocketCAN implementation provides alloc_candev() to
allocate a CAN device using a single Tx and Rx queue. This can lead to
priority inversion in case the single Tx queue is already full with low
priority messages and a high priority message needs to be sent while the
bus is fully loaded with medium priority messages.

This problem can be solved by using the existing multi-queue support of
the network subsytem. The commit makes it possible to use multi-queue in
the CAN subsystem in the same way it is used in the Ethernet subsystem
by adding an alloc_candev_mqs() call and accompanying macros. With this
support a CAN device can use multi-queue qdisc (e.g. mqprio) to avoid
the aforementioned priority inversion.

The exisiting functionality of alloc_candev() is the same as before.

CAN devices need to have prioritized multiple hardware queues or are
able to abort waiting for arbitration to make sensible use of
multi-queues.
Signed-off-by: Zhu Yi <yi.zhu5@cn.bosch.com>
Signed-off-by: Mark Jonas <mark.jonas@de.bosch.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

use helper skb_put_zero to replace the pattern of skb_put() && memset()
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The UCAN driver supports the microcontroller-based USB/CAN
adapters from Theobroma Systems. There are two form-factors
that run essentially the same firmware:

* Seal: standalone USB stick ( https://www.theobroma-systems.com/seal )

* Mule: integrated on the PCB of various System-on-Modules from
  Theobroma Systems like the A31-µQ7 and the RK3399-Q7
  ( https://www.theobroma-systems.com/rk3399-q7 )

The USB wire protocol has been designed to be as generic and
hardware-indendent as possible in the hope of being useful for
implementation on other microcontrollers.
Signed-off-by: Martin Elshuber <martin.elshuber@theobroma-systems.com>
Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch sorts the entries in the Kconfig and Makefile alphabetically,
so that further contributors can generate patches more easily.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Trivial fix to spelling mistake in module parameter description text
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

The CAN error masks header file is in the
include/uapi directory.

Fix the path in the header to the correct location.
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Saeed Mahameed says:

====================
mlx5e-updates-2018-07-26 (XDP redirect)

This series from Tariq adds the support for device-out XDP redirect.

Start with a simple RX and XDP cleanups:
- Replace call to MPWQE free with dealloc in interface down flow
- Do not recycle RX pages in interface down flow
- Gather all XDP pre-requisite checks in a single function
- Restrict the combination of large MTU and XDP

Since now XDP logic is going to be called from TX side as well,
generic XDP TX logic is not RX only anymore, for that Tariq creates
a new xdp.c file and moves XDP related code into it, and generalizes
the code to support XDP TX for XDP redirect, such as the xdp tx sq
structures and xdp counters.

XDP redirect support:
Add implementation for the ndo_xdp_xmit callback.

Dedicate a new set of XDP-SQ instances to satisfy the XDP_REDIRECT
requests.  These instances are totally separated from the existing
XDP-SQ objects that satisfy local XDP_TX actions.

Performance tests:

xdp_redirect_map from ConnectX-5 to ConnectX-5.
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz
Packet-rate of 64B packets.

Single queue: 7 Mpps.
Multi queue: 55 Mpps.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The root directories of netdevsim should only be used by the core
to create per-device subdirectories, so limit their visibility to
the core file.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tobin C. Harding says:

====================
docs: net: Convert netdev-FAQ to RST

Jon answered all the tree questions on v1 so if you will please take
this through your tree that would be awesome.

v2:
 - Fix typo 'canonical_path_format' (thanks Edward)
 - Add patch fixing references netdev-FAQ
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

File 'Documentation/networking/netdev-FAQ.txt' has been converted to RST
format.  We should update all links/references to point to the new file.

Update references to netdev-FAQ
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

Preferred kernel docs format is now restructured text.  Convert
netdev-FAQ.txt to restructured text.

 - Add SPDX license identifier.

 - Change file heading 'Information you need to know about netdev' to
  'netdev FAQ' to better suit displayed index (in HTML).

 - Change question/answer layout to suit rst.  Copy format in
   Documentation/bpf/bpf_devel_QA.rst

 - Fix indentation of code snippets

 - If multiple consecutive URLs appear put them in a list (to maintain
  whitespace).

 - Use uniform spelling of 'bug fix' throughout document (not bugfix or
   bug-fix).

 - Add double back ticks to 'net' and 'net-next' when referring to the
   trees.

 - Use rst references for Documentation/ links.

 - Add rst label 'netdev-FAQ' for referencing by other docs files.

 - Remove stale entry from Documentation/networking/00-INDEX
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation to convert Documentation/network/netdev-FAQ.rst to
restructured text format.  We would like to be able to reference 'the
canonical patch format' section.

Add rest label: 'the_canonical_patch_format'.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

starfire_init_one() is never called in atomic context.
It calls mdelay() to busily wait, which is not necessary.
mdelay() can be replaced with msleep().

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hisax_cs_new() and hisax_cs_setup() are never called in atomic context.
They call kmalloc() and kzalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

init_PStack() is never called in atomic context.
It calls kmalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

nj_probe() is never called in atomic context.
It calls kzalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hfc_probe() is never called in atomic context.
It calls kzalloc() with GFP_ATOMIC, which is not necessary.
GFP_ATOMIC can be replaced with GFP_KERNEL.

This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hns_dsaf_roce_reset is exported and used in hns_roce_hw_v1.c
In commit 336a443b ("net: hns: Make many functions static") I make
it static wrongly.

drivers/infiniband/hw/hns/hns_roce_hw_v1.o: In function `hns_roce_v1_reset':
hns_roce_hw_v1.c:(.text+0x37ac): undefined reference to `hns_dsaf_roce_reset'
hns_roce_hw_v1.c:(.text+0x37cc): undefined reference to `hns_dsaf_roce_reset'

Fixes: 336a443b ("net: hns: Make many functions static")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use designated function mlx5e_dma_get() to get
the mlx5e_sq_dma object to be pushed into fifo.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Pointers in DB are static, move them to read-only area so they
do not share a cacheline with fields modified in datapath.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

A loaded XDP program might write to the xdp_frame data area,
prefetchw() it to avoid a potential cache miss.

Performance tests:
ConnectX-5, XDP_TX packet rate, single ring.
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz

Before: 13,172,976 pps
After:  13,456,248 pps
2% gain.

Fixes: 22f45398 ("net/mlx5e: Support XDP over Striding RQ")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Add implementation for the ndo_xdp_xmit callback.

Dedicate a new set of XDP-SQ instances to satisfy the XDP_REDIRECT
requests.  These instances are totally separated from the existing
XDP-SQ objects that satisfy local XDP_TX actions.

Performance tests:

xdp_redirect_map from ConnectX-5 to ConnectX-5.
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz
Packet-rate of 64B packets.

Single queue: 7 Mpps.
Multi queue: 55 Mpps.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

In the downstream patch that adds support to XDP_REDIRECT-out,
the XDP xmit frame function doesn't share the same run context as
the NAPI that polls the XDP-SQ completion queue.

Hence, need to re-order the XDP-SQ fields to avoid cacheline
false-sharing.

Take redirect_flush and doorbell out of DB, into separated
cachelines.

Add a cacheline breaker within the stats struct.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Separate the XDP counters into two sets:
(1) One set reside in the RQ stats, and they monitor XDP stats
in the RQ side.
(2) Another set is per XDP-SQ, and they monitor XDP stats that
are related to XDP transmit flow.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Convert the XDP xmit functions to use the generic xdp_frame API
in XDP_TX flow.
Same functions will be used later in this series to transmit
the XDP redirect-out packets as well.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Add per-ring and total stats for received packets that
goes into XDP redirection.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Take XDP code out of the general EN header and RX file into
new XDP files.

Currently, XDP-SQ resides only within an RQ and used from a
single flow (XDP_TX) triggered upon RX completions.
In a downstream patch, additional type of XDP-SQ instances will be
presented and used for the XDP_REDIRECT flow, totally unrelated to
the RX context.
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>