Lee Jones says:

====================
Rid W=1 warnings from PTP

This set is part of a larger effort attempting to clean-up W=1
kernel builds, which are currently overwhelmingly riddled with
niggly little warnings.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following W=1 kernel build warning(s):

 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'control' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'event' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'addend' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'accum' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'test' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'ts_compare' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'rsystime_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'rsystime_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'systime_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'systime_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'trgt_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'trgt_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'asms_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'asms_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'amms_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'amms_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'ch_control' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'ch_event' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'tx_snap_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'tx_snap_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'rx_snap_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'rx_snap_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'src_uuid_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'src_uuid_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'can_status' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'can_snap_lo' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'can_snap_hi' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'ts_sel' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'ts_st' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'reserve1' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'stl_max_set_en' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'stl_max_set' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'reserve2' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:78: warning: Function parameter or member 'srst' not described in 'pch_ts_regs'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'regs' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'ptp_clock' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'caps' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'exts0_enabled' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'exts1_enabled' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'mem_base' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'mem_size' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'irq' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'pdev' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:121: warning: Function parameter or member 'register_lock' not described in 'pch_dev'
 drivers/ptp/ptp_pch.c:128: warning: Function parameter or member 'station' not described in 'pch_params'
 drivers/ptp/ptp_pch.c:291: warning: Function parameter or member 'pdev' not described in 'pch_set_station_address'

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: LAPIS SEMICONDUCTOR <tshimizu818@gmail.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following W=1 kernel build warning(s):

 drivers/ptp/ptp_clockmatrix.c:1408: warning: Cannot understand  * @brief Maximum absolute value for write phase offset in picoseconds
 drivers/ptp/ptp_clockmatrix.c:1408: warning: Cannot understand  * @brief Maximum absolute value for write phase offset in picoseconds
 drivers/ptp/ptp_clockmatrix.c:1408: warning: Cannot understand  * @brief Maximum absolute value for write phase offset in picoseconds
 drivers/ptp/ptp_clockmatrix.c:1408: warning: Cannot understand  * @brief Maximum absolute value for write phase offset in picoseconds
 drivers/ptp/ptp_clockmatrix.c:1408: warning: Cannot understand  * @brief Maximum absolute value for write phase offset in picoseconds

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: IDT-support-1588@lm.renesas.com
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following W=1 kernel build warning(s):

 drivers/ptp/ptp_pch.c:193:6: warning: no previous prototype for ‘pch_ch_control_write’ [-Wmissing-prototypes]
 drivers/ptp/ptp_pch.c:201:5: warning: no previous prototype for ‘pch_ch_event_read’ [-Wmissing-prototypes]
 drivers/ptp/ptp_pch.c:212:6: warning: no previous prototype for ‘pch_ch_event_write’ [-Wmissing-prototypes]
 drivers/ptp/ptp_pch.c:220:5: warning: no previous prototype for ‘pch_src_uuid_lo_read’ [-Wmissing-prototypes]
 drivers/ptp/ptp_pch.c:231:5: warning: no previous prototype for ‘pch_src_uuid_hi_read’ [-Wmissing-prototypes]
 drivers/ptp/ptp_pch.c:242:5: warning: no previous prototype for ‘pch_rx_snap_read’ [-Wmissing-prototypes]
 drivers/ptp/ptp_pch.c:259:5: warning: no previous prototype for ‘pch_tx_snap_read’ [-Wmissing-prototypes]
 drivers/ptp/ptp_pch.c:300:5: warning: no previous prototype for ‘pch_set_station_address’ [-Wmissing-prototypes]

Cc: Richard Cochran <richardcochran@gmail.com> (maintainer:PTP HARDWARE CLOCK SUPPORT)
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Flavio Suligoi <f.suligoi@asem.it>
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following W=1 kernel build warning(s):

 drivers/ptp/ptp_pch.c:182:5: warning: no previous prototype for ‘pch_ch_control_read’ [-Wmissing-prototypes]

Cc: Richard Cochran <richardcochran@gmail.com> (maintainer:PTP HARDWARE CLOCK SUPPORT)
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Flavio Suligoi <f.suligoi@asem.it>
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

On some SoCs (e.g. BCM4908, BCM631[345]8) SF2 has an integrated
crossbar. It allows connecting its selected external ports to internal
ports. It's used by vendors to handle custom Ethernet setups.

BCM4908 has following 3x2 crossbar. On Asus GT-AC5300 rgmii is used for
connecting external BCM53134S switch. GPHY4 is usually used for WAN
port. More fancy devices use SerDes for 2.5 Gbps Ethernet.

              ┌──────────┐
SerDes ─── 0 ─┤          │
              │   3x2    ├─ 0 ─── switch port 7
 GPHY4 ─── 1 ─┤          │
              │ crossbar ├─ 1 ─── runner (accelerator)
 rgmii ─── 2 ─┤          │
              └──────────┘

Use setup data based on DT info to configure BCM4908's switch port 7.
Right now only GPHY and rgmii variants are supported. Handling SerDes
can be implemented later.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It's needed later for proper switch / crossbar setup.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

All comment lines inside the comment block have been aligned.
Every line of comment starts with a * (uniformity in code).
Signed-off-by: Shubhankar Kuranagatti <shubhankarvk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It appears that each DMA channel has its own interrupt and both rings
can be configured (the same way) to handle interrupts.

1. Make ring interrupts code generic (make it operate on given ring)
2. Move napi to ring (so each has its own)
3. Make IRQ handler generic (match ring against received IRQ number)
4. Add (optional) support for TX interrupt
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

I discovered that hardware actually supports two interrupts, one per DMA
channel (RX and TX).
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

Robert Hancock says:

====================
macb SGMII fixed-link fixes

Some fixes to the macb driver for use in SGMII mode with a fixed-link (such as
for chip-to-chip connectivity).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When using a fixed-link configuration in SGMII mode, it's not really
sensible to have auto-negotiation enabled since the link settings are
fixed by definition. In other configurations, such as an SGMII
connection to a PHY, it should generally be enabled.
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When using a fixed-link configuration with GEM in SGMII mode, such as
for a chip-to-chip interconnect, the link state was always showing as
established regardless of the actual connectivity state. We can monitor
the pcs_link_state bit in the Network Status register to determine
whether the PCS link state is actually up.
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-updates-2021-03-12

1) TC support for ICMP parameters
2) TC connection tracking with mirroring
3) A round of trivial fixups and cleanups
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Support matching on ICMPv4/6 type and code parameters using misc3
section of match parameters.
Signed-off-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Add support for mirroring before the CT action by spliting the pre ct rule.
Mirror outputs are done first on the tc chain,prio table rule (the fwd
rule), which will then forward to a per port fwd table.
On this fwd table, we insert the original pre ct rule that forwards to
ct/ct nat table.
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Maor Dickman <maord@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Multiple commands can be printed at the same time which can
lead to wrong order of their lines in dmesg output.
As a result, it's hard to match data dumps to the correct command
or which command was fully dumped at some point.

Fix this by displaying the corresponding command index, and also
indicate when a command was fully dumped.
Signed-off-by: Alaa Hleihel <alaa@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Increasing the size of the indirection_rqt array from 128 to 256 bytes
pushed the stack usage of the mlx5e_hairpin_fill_rqt_rqns() function
over the warning limit when building with clang and CONFIG_KASAN:

drivers/net/ethernet/mellanox/mlx5/core/en_tc.c:970:1: error: stack frame size of 1180 bytes in function 'mlx5e_tc_add_nic_flow' [-Werror,-Wframe-larger-than=]

Using dynamic allocation here is safe because the caller does the
same, and it reduces the stack usage of the function to just a few
bytes.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Dump the ICOSQ's WQE descriptor when a completion with error is received.
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Commit e20f0dbf ("net/mlx5e: RX, Add a prefetch command for small
L1_CACHE_BYTES") switched to using net_prefetchw at all places in mlx5e.
In the same time frame, commit 5af75c74 ("net/mlx5e: Enhanced TX
MPWQE for SKBs") added one more usage of prefetchw. When these two
changes were merged, this new occurrence of prefetchw wasn't replaced
with net_prefetchw.

This commit fixes this last occurrence of prefetchw in
mlx5e_tx_mpwqe_session_start, making the same change that was done in
mlx5e_xdp_mpwqe_session_start.
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Fix the following coccicheck warnings:

drivers/net/ethernet/mellanox/mlx5/core/devlink.c:145:29-66: WARNING
avoid newline at end of message in NL_SET_ERR_MSG_MOD
drivers/net/ethernet/mellanox/mlx5/core/devlink.c:140:29-77: WARNING
avoid newline at end of message in NL_SET_ERR_MSG_MOD
Signed-off-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Read congestion counters from all ports in any lag mode rather than
only in RoCE lag mode (e.g., VF lag).
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Fix the following coccicheck warnings:

./drivers/net/ethernet/mellanox/mlx5/core/sf/devlink.c:495:2-3: Unneeded
semicolon.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

It is allocated with kvzalloc(), the corresponding release function
should not be kfree(), use kvfree() instead.

Generated by: scripts/coccinelle/api/kfree_mismatch.cocci
Signed-off-by: Junlin Yang <yangjunlin@yulong.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

The field source_eswitch_owner_vhca_id was not consumed
in the same way as in STEv0. Added the missing set.

Fixes: 10b69418 ("net/mlx5: DR, Add HW STEv1 match logic")
Signed-off-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

Remove the dr_ste_v1_set_rx_decap_l3 function that was
replaced by another function - fixing a rebase error.
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

"reforamt" -> "reformat"
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Reviewed-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

"either" is outside the parentheses, so the matching "or" should be too.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: better deal with delayed TX completions

Jakub and Neil reported an increase of RTO timers whenever
TX completions are delayed a bit more (by increasing
NIC TX coalescing parameters)

While problems have been there forever, second patch might
introduce some regressions so I prefer not backport
them to stable releases before things settle.

Many thanks to FB team for their help and tests.

Few packetdrill tests need to be changed to reflect
the improvements brought by this series.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

TSQ provides a nice way to avoid bufferbloat on individual socket,
including retransmit packets. We can get rid of the old
heuristic:

	/* Do not sent more than we queued. 1/4 is reserved for possible
	 * copying overhead: fragmentation, tunneling, mangling etc.
	 */
	if (refcount_read(&sk->sk_wmem_alloc) >
	    min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2),
		  sk->sk_sndbuf))
		return -EAGAIN;

This heuristic was giving false positives according to Jakub,
whenever TX completions are delayed above RTT. (Ack packets
are processed by TCP stack before clones are orphaned/freed)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jakub Kicinski <kuba@kernel.org>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub reported Data included in a Fastopen SYN that had to be
retransmit would have to wait for an RTO if TX completions are slow,
even with prior fix.

This is because tcp_rcv_fastopen_synack() does not use standard
rtx logic, meaning TSQ handler exits early in tcp_tsq_write()
because tp->lost_out == tp->retrans_out

Lets make tcp_rcv_fastopen_synack() use standard rtx logic,
by using tcp_mark_skb_lost() on the skb thats needs to be
sent again.

Not this raised a warning in tcp_fastretrans_alert() during my tests
since we consider the data not being aknowledged
by the receiver does not mean packet was lost on the network.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jakub Kicinski <kuba@kernel.org>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub and Neil reported an increase of RTO timers whenever
TX completions are delayed a bit more (by increasing
NIC TX coalescing parameters)

Main issue is that TCP stack has a logic preventing a packet
being retransmit if the prior clone has not yet been
orphaned or freed.

This logic came with commit 1f3279ae ("tcp: avoid
retransmits of TCP packets hanging in host queues")

Thankfully, in the case skb_still_in_host_queue() detects
the initial clone is still in flight, it can use TSQ logic
that will eventually retry later, at the moment the clone
is freed or orphaned.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Neil Spring <ntspring@fb.com>
Reported-by: Jakub Kicinski <kuba@kernel.org>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

fix some coding style issues in the isdn header
Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes the following warning from sparse:

net/tipc/monitor.c:263:35: warning: incorrect type in assignment (different base types)
net/tipc/monitor.c:263:35:    expected unsigned int
net/tipc/monitor.c:263:35:    got restricted __be32 [usertype]
[...]
net/tipc/node.c:374:13: warning: context imbalance in 'tipc_node_read_lock' - wrong count at exit
net/tipc/node.c:379:13: warning: context imbalance in 'tipc_node_read_unlock' - unexpected unlock
net/tipc/node.c:384:13: warning: context imbalance in 'tipc_node_write_lock' - wrong count at exit
net/tipc/node.c:389:13: warning: context imbalance in 'tipc_node_write_unlock_fast' - unexpected unlock
net/tipc/node.c:404:17: warning: context imbalance in 'tipc_node_write_unlock' - unexpected unlock
[...]
net/tipc/crypto.c:1201:9: warning: incorrect type in initializer (different address spaces)
net/tipc/crypto.c:1201:9:    expected struct tipc_aead [noderef] __rcu *__tmp
net/tipc/crypto.c:1201:9:    got struct tipc_aead *
[...]
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Hoang Huu Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

(struct tipc_link_info)->dest is in network order (__be32), so we must
convert the value to network order before assigning. The problem detected
by sparse:

net/tipc/netlink_compat.c:699:24: warning: incorrect type in assignment (different base types)
net/tipc/netlink_compat.c:699:24:    expected restricted __be32 [usertype] dest
net/tipc/netlink_compat.c:699:24:    got int
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Implement sampling using mirroring

So far, sampling was implemented using a dedicated sampling mechanism
that is available on all Spectrum ASICs. Spectrum-2 and later ASICs
support sampling by mirroring packets to the CPU port with probability.
This method has a couple of advantages compared to the legacy method:

* Extra metadata per-packet: Egress port, egress traffic class, traffic
  class occupancy and end-to-end latency
* Ability to sample packets on egress / per-flow as opposed to only
  ingress

This series should not result in any user-visible changes and its aim is
to convert Spectrum-2 and later ASICs to perform sampling by mirroring
to the CPU port with probability. Future submissions will expose the
additional metadata and enable sampling using more triggers (e.g.,
egress).

Series overview:

Patches #1-#3 extend the SPAN (mirroring) module to accept new
parameters required for sampling. See individual commit messages for
detailed explanation.

Patch #4-#5 split sampling support between Spectrum-1 and later ASIC while
still using the legacy method for all ASIC generations.

Patch #6 converts Spectrum-2 and later ASICs to perform sampling by
mirroring to the CPU port with probability.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Spectrum-2 and later ASICs support sampling of packets by mirroring to
the CPU with probability. There are several advantages compared to the
legacy dedicated sampling mechanism:

* Extra metadata per-packet: Egress port, egress traffic class, traffic
  class occupancy and end-to-end latency
* Ability to sample packets on egress / per-flow

Convert Spectrum-2 and later ASICs to perform sampling by mirroring to
the CPU with probability.

Subsequent patches will add support for egress / per-flow sampling and
expose the extra metadata.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sampling of ingress packets is supported using a dedicated sampling
mechanism on all Spectrum ASICs. However, Spectrum-2 and later ASICs
support more sophisticated sampling by mirroring packets to the CPU.

As a preparation for more advanced sampling configurations, split the trap
configuration used for sampled packets between Spectrum-1 and later ASICs.

This is needed since packets that are mirrored to the CPU are trapped
via a different trap identifier compared to packets that are sampled
using the dedicated sampling mechanism.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sampling of ingress packets is supported using a dedicated sampling
mechanism on all Spectrum ASICs. However, Spectrum-2 and later ASICs
support more sophisticated sampling by mirroring packets to the CPU.

As a preparation for more advanced sampling configurations, split the
sampling operations between Spectrum-1 and later ASICs.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, every packet that matches a mirroring trigger (e.g., received
packets, buffer dropped packets) is mirrored. Spectrum-2 and later ASICs
support mirroring with probability, where every 1 in N matched packets
is mirrored.

Extend the API that creates the binding between the trigger and the SPAN
agent with a probability rate parameter, which is an attribute of the
trigger. Set it to '1' to maintain existing behavior.

Subsequent patches will use it to perform more sophisticated sampling,
by mirroring packets to the CPU with probability.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>