mlxbf_gige: add support to display pause frame counters

This patch updates the mlxbf_gige driver to support the
"get_pause_stats()" callback, which enables display of
pause frame counters via "ethtool -I -a oob_net0".

The pause frame counters are only enabled if the "counters_en"
bit is asserted in the LLU general config register. The driver
will only report stats, and thus overwrite the default stats
state of ETHTOOL_STAT_NOT_SET, if "counters_en" is asserted.

Reviewed-by: Asmaa Mnebhi <asmaa@nvidia.com>
Signed-off-by: David Thompson <davthompson@nvidia.com>
Link: https://lore.kernel.org/r/20240305212137.3525-1-davthompson@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mlxbf_gige: add "set_link_ksettings" ethtool callback

This patch extends the "ethtool_ops" data structure to
include the "set_link_ksettings" callback. This change
enables configuration of the various interface speeds
that the BlueField-3 supports (10Mbps, 100Mbps, and 1Gbps).

Signed-off-by: David Thompson <davthompson@nvidia.com>
Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mlxbf_gige: remove driver-managed interrupt counts

The driver currently has three interrupt counters,
which are incremented every time each interrupt handler
executes. These driver-managed counters are not
necessary as the kernel already has logic that manages
interrupt counts and exposes them via /proc/interrupts.
This patch removes the driver-managed counters.

Signed-off-by: David Thompson <davthompson@nvidia.com>
Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Link: https://lore.kernel.org/r/20220511135251.2989-1-davthompson@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ethtool: extend ringparam setting/getting API with rx_buf_len

Add two new parameters kernel_ringparam and extack for
.get_ringparam and .set_ringparam to extend more ring params
through netlink.

Signed-off-by: Hao Chen <chenhao288@hisilicon.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add Mellanox BlueField Gigabit Ethernet driver

This patch adds build and driver logic for the "mlxbf_gige"
Ethernet driver from Mellanox Technologies. The second
generation BlueField SoC from Mellanox supports an
out-of-band GigaBit Ethernet management port to the Arm
subsystem. This driver supports TCP/IP network connectivity
for that port, and provides back-end routines to handle
basic ethtool requests.

The driver interfaces to the Gigabit Ethernet block of
BlueField SoC via MMIO accesses to registers, which contain
control information or pointers describing transmit and
receive resources. There is a single transmit queue, and
the port supports transmit ring sizes of 4 to 256 entries.
There is a single receive queue, and the port supports
receive ring sizes of 32 to 32K entries. The transmit and
receive rings are allocated from DMA coherent memory. There
is a 16-bit producer and consumer index per ring to denote
software ownership and hardware ownership, respectively.

The main driver logic such as probe(), remove(), and netdev
ops are in "mlxbf_gige_main.c". Logic in "mlxbf_gige_rx.c"
and "mlxbf_gige_tx.c" handles the packet processing for
receive and transmit respectively.

The logic in "mlxbf_gige_ethtool.c" supports the handling
of some basic ethtool requests: get driver info, get ring
parameters, get registers, and get statistics.

The logic in "mlxbf_gige_mdio.c" is the driver controlling
the Mellanox BlueField hardware that interacts with a PHY
device via MDIO/MDC pins. This driver does the following:
- At driver probe time, it configures several BlueField MDIO
parameters such as sample rate, full drive, voltage and MDC
- It defines functions to read and write MDIO registers and
registers the MDIO bus.
- It defines the phy interrupt handler reporting a
link up/down status change
- This driver's probe is invoked from the main driver logic
while the phy interrupt handler is registered in ndo_open.

Driver limitations
- Only supports 1Gbps speed
- Only supports GMII protocol
- Supports maximum packet size of 2KB
- Does not support scatter-gather buffering

Testing
- Successful build of kernel for ARM64, ARM32, X86_64
- Tested ARM64 build on FastModels & Palladium
- Tested ARM64 build on several Mellanox boards that are built with
the BlueField-2 SoC. The testing includes coverage in the areas
of networking (e.g. ping, iperf, ifconfig, route), file transfers
(e.g. SCP), and various ethtool options relevant to this driver.

Signed-off-by: David Thompson <davthompson@nvidia.com>
Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
Reviewed-by: Liming Sun <limings@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>