net/mlx5e: simplify condition after napi budget handling change

Since recent commit budget can't be 0 here.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

net/mlx5e: do as little as possible in napi poll when budget is 0

NAPI gets called with budget of 0 from netpoll, which has interrupts
disabled. We should try to free some space on Tx rings and nothing
else.

Specifically do not try to handle XDP TX or try to refill Rx buffers -
we can't use the page pool from IRQ context. Don't check if IRQs moved,
either, that makes no sense in netpoll. Netpoll calls _all_ the rings
from whatever CPU it happens to be invoked on.

In general do as little as possible, the work quickly adds up when
there's tens of rings to poll.

The immediate stack trace I was seeing is:

__do_softirq+0xd1/0x2c0
__local_bh_enable_ip+0xc7/0x120
</IRQ>
<TASK>
page_pool_put_defragged_page+0x267/0x320
mlx5e_free_xdpsq_desc+0x99/0xd0
mlx5e_poll_xdpsq_cq+0x138/0x3b0
mlx5e_napi_poll+0xc3/0x8b0
netpoll_poll_dev+0xce/0x150

AFAIU page pool takes a BH lock, releases it and since BH is now
enabled tries to run softirqs.

Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Fixes: 60bbf7eeef10 ("mlx5: use page_pool for xdp_return_frame call")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Rename RQ/SQ adaptive moderation state flag

Dynamic interrupt moderation RQ and SQ feature represented by
MLX5E_RQ_STATE_AM and MLX5E_SQ_STATE_AM enums respectively, is not
consistent with the feature naming in the driver, and with the formal
feature and library names.

Hence, change MLX5E_RQ_STATE_AM and MLX5E_SQ_STATE_AM enum type names in
core/en.h to MLX5E_RQ_STATE_DIM and MLX5E_SQ_STATE_DIM respectively.

Signed-off-by: Adham Faris <afaris@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20230314054234.267365-7-saeed@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mlx5e: xsk: Improve need_wakeup logic

XSK need_wakeup mechanism allows the driver to stop busy waiting for
buffers when the fill ring is empty, yield to the application and signal
it that the driver needs to be waken up after the application refills
the fill ring.

Add protection against the race condition on the RX (refill) side: if
the application refills buffers after xskrq->post_wqes is called, but
before mlx5e_xsk_update_rx_wakeup, NAPI will exit, skipping taking these
buffers to the hardware WQ, and the application won't wake it up again.

Optimize the whole need_wakeup logic, removing unneeded flows, to
compensate for this new check.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mlx5e: kTLS, Add resiliency to RX resync failures

When the TLS logic finds a tcp seq match for a kTLS RX resync
request, it calls the driver callback function mlx5e_ktls_resync()
to handle it and communicate it to the device.

Errors might occur during mlx5e_ktls_resync(), however, they are not
reported to the stack. Moreover, there is no error handling in the
stack for these errors.

In this patch, the driver obtains responsibility on errors handling,
adding queue and retry mechanisms to these resyncs.

We maintain a linked list of resync matches, and try posting them
to the async ICOSQ in the NAPI context.

Only possible failure that demands driver handling is ICOSQ being full.
By relying on the NAPI mechanism, we make sure that the entries in list
will be handled when ICOSQ completions arrive and make some room
available.

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

net/mlx5e: Support HTB offload

This commit adds support for HTB offload in the mlx5e driver.

Performance:

NIC: Mellanox ConnectX-6 Dx
CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz (24 cores with HT)

100 Gbit/s line rate, 500 UDP streams @ ~200 Mbit/s each
48 traffic classes, flower used for steering
No shaping (rate limits set to 4 Gbit/s per TC) - checking for max
throughput.

Baseline: 98.7 Gbps, 8.25 Mpps
HTB: 6.7 Gbps, 0.56 Mpps
HTB offload: 95.6 Gbps, 8.00 Mpps

Limitations:

1. 256 leaf nodes, 3 levels of depth.

2. Granularity for ceil is 1 Mbit/s. Rates are converted to weights, and
the bandwidth is split among the siblings according to these weights.
Other parameters for classes are not supported.

Ethtool statistics support for QoS SQs are also added. The counters are
called qos_txN_*, where N is the QoS queue number (starting from 0, the
numeration is separate from the normal SQs), and * is the counter name
(the counters are the same as for the normal SQs).

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/mlx5: Replace irq_to_desc() abuse

No driver has any business with the internals of an interrupt
descriptor. Storing a pointer to it just to use yet another helper at the
actual usage site to retrieve the affinity mask is creative at best. Just
because C does not allow encapsulation does not mean that the kernel has no
limits.

Retrieve a pointer to the affinity mask itself and use that. It's still
using an interface which is usually not for random drivers, but definitely
less hideous than the previous hack.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Link: https://lore.kernel.org/r/20201210194044.769458162@linutronix.de

net/mlx5e: Allow CQ outside of channel context

In order to be able to create a CQ outside of a channel context, remove
cq->channel direct pointer. This requires adding a direct pointer to
channel statistics, netdevice, priv and to mlx5_core in order to support
CQs that are a part of mlx5e_channel.
In addition, parameters the were previously derived from the channel
like napi, NUMA node, channel stats and index are now assembled in
struct mlx5e_create_cq_param which is given to mlx5e_open_cq() instead
of channel pointer. Generalizing mlx5e_open_cq() allows opening CQ
outside of channel context which will be used in following patches in
the patch-set.

Signed-off-by: Aya Levin <ayal@nvidia.com>
Signed-off-by: Eran Ben Elisha <eranbe@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

net/mlx5e: Use synchronize_rcu to sync with NAPI

As described in the previous commit, napi_synchronize doesn't quite fit
the purpose when we just need to wait until the currently running NAPI
quits. Its implementation waits until NAPI is not running by polling and
waiting for 1ms in between. In cases where we need to deactivate one
queue (e.g., recovery flows) or where we deactivate them one-by-one
(deactivate channel flow), we may get stuck in napi_synchronize forever
if other queues keep NAPI active, causing a soft lockup. Depending on
kernel configuration (CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC), it may result
in a kernel panic.

To fix the issue, use synchronize_rcu to wait for NAPI to quit, and wrap
the whole NAPI in rcu_read_lock.

Fixes: acc6c5953af1 ("net/mlx5e: Split open/close channels to stages")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Use indirect call wrappers for RX post WQEs functions

Use the indirect call wrapper API macros for declaration and scope
of the RX post WQEs functions.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Turn XSK ICOSQ into a general asynchronous one

There is an upcoming demand (in downstream patches) for
an ICOSQ to be populated out of the NAPI context, asynchronously.

There is already an existing one serving XSK-related use case.
In this patch, promote this ICOSQ to serve as general async ICOSQ,
to be used for XSK and non-XSK flows.

As part of this, the reg_umr bit of the SQ context is now set
(if capable), as the general async ICOSQ should support possible
posts of UMR WQEs.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Enhance ICOSQ WQE info fields

The same WQE opcode might be used in different ICOSQ flows
and WQE types.
To have a better distinguishability, replace it with an enum that
better indicates the WQE type and flow it is used for.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Use struct assignment for WQE info updates

Struct assignment looks more clean, and implies resetting
the not assigned fields to zero, instead of holding values
from older ring cycles.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Rename ICOSQ WQE info struct and field

Structs mlx5e_txqsq and mlx5e_xdpsq contain wqe_info arrays to store
supplementary information corresponding to WQEs in the queue. Struct
mlx5e_icosq also has such an array, but it's called differently -
ico_wqe. This patch renames it to unify with the other SQs.

In addition, rename the struct to emphasize its specific usage.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Don't trigger IRQ multiple times on XSK wakeup to avoid WQ overruns

XSK wakeup function triggers NAPI by posting a NOP WQE to a special XSK
ICOSQ. When the application floods the driver with wakeup requests by
calling sendto() in a certain pattern that ends up in mlx5e_trigger_irq,
the XSK ICOSQ may overflow.

Multiple NOPs are not required and won't accelerate the process, so
avoid posting a second NOP if there is one already on the way. This way
we also avoid increasing the queue size (which might not help anyway).

Fixes: db05815b36cb ("net/mlx5e: Add XSK zero-copy support")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Enhance ICOSQ WQE info fields

Add number of WQEBBs (WQE's Basic Block) to WQE info struct. Set the
number of WQEBBs on WQE post, and increment the consumer counter (cc)
on completion.

In case of error completions, the cc was mistakenly not incremented,
keeping a gap between cc and pc (producer counter). This failed the
recovery flow on the ICOSQ from a CQE error which timed-out waiting for
the cc and pc to meet.

Fixes: be5323c8379f ("net/mlx5e: Report and recover from CQE error on ICOSQ")
Signed-off-by: Aya Levin <ayal@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: RX, Use indirect calls wrapper for posting descriptors

We can avoid an indirect call per NAPI cycle wrapping the RX descriptors
posting call with the appropriate helper.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Add AF_XDP need_wakeup support

This commit adds support for the new need_wakeup feature of AF_XDP. The
applications can opt-in by using the XDP_USE_NEED_WAKEUP bind() flag.
When this feature is enabled, some behavior changes:

RX side: If the Fill Ring is empty, instead of busy-polling, set the
flag to tell the application to kick the driver when it refills the Fill
Ring.

TX side: If there are pending completions or packets queued for
transmission, set the flag to tell the application that it can skip the
sendto() syscall and save time.

The performance testing was performed on a machine with the following
configuration:

- 24 cores of Intel Xeon E5-2620 v3 @ 2.40 GHz
- Mellanox ConnectX-5 Ex with 100 Gbit/s link

The results with retpoline disabled:

| without need_wakeup | with need_wakeup |
|----------------------|----------------------|
| one core | two cores | one core | two cores |
-------|----------|-----------|----------|-----------|
txonly | 20.1 | 33.5 | 29.0 | 34.2 |
rxdrop | 0.065 | 14.1 | 12.0 | 14.1 |
l2fwd | 0.032 | 7.3 | 6.6 | 7.2 |

"One core" means the application and NAPI run on the same core. "Two
cores" means they are pinned to different cores.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

net/mlx5e: Move the SW XSK code from NAPI poll to a separate function

Two XSK tasks are performed during NAPI polling, that are not bound to
hardware interrupts: TXing packets and polling for frames in the Fill
Ring. They are special in a way that the hardware doesn't know about
these tasks, so it doesn't trigger interrupts if there is still some
work to be done, it's our driver's responsibility to ensure NAPI will be
rescheduled if needed.

Create a new function to handle these tasks and move the corresponding
code from mlx5e_napi_poll to the new function to improve modularity and
prepare for the changes in the following patch.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

linux/dim: Fix overflow in dim calculation

While using net_dim, a dim_sample was used without ever initializing the
comps value. Added use of DIV_ROUND_DOWN_ULL() to prevent potential
overflow, it should not be a problem to save the final result in an int
because after the division by epms the value should not be larger than a
few thousand.

[ 1040.127124] UBSAN: Undefined behaviour in lib/dim/dim.c:78:23
[ 1040.130118] signed integer overflow:
[ 1040.131643] 134718714 * 100 cannot be represented in type 'int'

Fixes: 398c2b05bbee ("linux/dim: Add completions count to dim_sample")
Signed-off-by: Yamin Friedman <yaminf@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5: Report EQE data upon CQ completion

Report EQE data upon CQ completion to let upper layers use this data.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

net/mlx5e: Add XSK zero-copy support

This commit adds support for AF_XDP zero-copy RX and TX.

We create a dedicated XSK RQ inside the channel, it means that two
RQs are running simultaneously: one for non-XSK traffic and the other
for XSK traffic. The regular and XSK RQs use a single ID namespace split
into two halves: the lower half is regular RQs, and the upper half is
XSK RQs. When any zero-copy AF_XDP socket is active, changing the number
of channels is not allowed, because it would break to mapping between
XSK RQ IDs and channels.

XSK requires different page allocation and release routines. Such
functions as mlx5e_{alloc,free}_rx_mpwqe and mlx5e_{get,put}_rx_frag are
generic enough to be used for both regular and XSK RQs, and they use the
mlx5e_page_{alloc,release} wrappers around the real allocation
functions. Function pointers are not used to avoid losing the
performance with retpolines. Wherever it's certain that the regular
(non-XSK) page release function should be used, it's called directly.

Only the stats that could be meaningful for XSK are exposed to the
userspace. Those that don't take part in the XSK flow are not
considered.

Note that we don't wait for WQEs on the XSK RQ (unlike the regular RQ),
because the newer xdpsock sample doesn't provide any Fill Ring entries
at the setup stage.

We create a dedicated XSK SQ in the channel. This separation has its
advantages:

1. When the UMEM is closed, the XSK SQ can also be closed and stop
receiving completions. If an existing SQ was used for XSK, it would
continue receiving completions for the packets of the closed socket. If
a new UMEM was opened at that point, it would start getting completions
that don't belong to it.

2. Calculating statistics separately.

When the userspace kicks the TX, the driver triggers a hardware
interrupt by posting a NOP to a dedicated XSK ICO (internal control
operations) SQ, in order to trigger NAPI on the right CPU core. This XSK
ICO SQ is protected by a spinlock, as the userspace application may kick
the TX from any core.

Store the pointers to the UMEMs in the net device private context,
independently from the kernel. This way the driver can distinguish
between the zero-copy and non-zero-copy UMEMs. The kernel function
xdp_get_umem_from_qid does not care about this difference, but the
driver is only interested in zero-copy UMEMs, particularly, on the
cleanup it determines whether to close the XSK RQ and SQ or not by
looking at the presence of the UMEM. Use state_lock to protect the
access to this area of UMEM pointers.

LRO isn't compatible with XDP, but there may be active UMEMs while
XDP is off. If this is the case, don't allow LRO to ensure XDP can
be reenabled at any time.

The validation of XSK parameters typically happens when XSK queues
open. However, when the interface is down or the XDP program isn't
set, it's still possible to have active AF_XDP sockets and even to
open new, but the XSK queues will be closed. To cover these cases,
perform the validation also in these flows:

1. A new UMEM is registered, but the XSK queues aren't going to be
created due to missing XDP program or interface being down.

2. MTU changes while there are UMEMs registered.

Having this early check prevents mlx5e_open_channels from failing
at a later stage, where recovery is impossible and the application
has no chance to handle the error, because it got the successful
return value for an MTU change or XSK open operation.

The performance testing was performed on a machine with the following
configuration:

- 24 cores of Intel Xeon E5-2620 v3 @ 2.40 GHz
- Mellanox ConnectX-5 Ex with 100 Gbit/s link

The results with retpoline disabled, single stream:

txonly: 33.3 Mpps (21.5 Mpps with queue and app pinned to the same CPU)
rxdrop: 12.2 Mpps
l2fwd: 9.4 Mpps

The results with retpoline enabled, single stream:

txonly: 21.3 Mpps (14.1 Mpps with queue and app pinned to the same CPU)
rxdrop: 9.9 Mpps
l2fwd: 6.8 Mpps

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

net/mlx5e: Share the XDP SQ for XDP_TX between RQs

Put the XDP SQ that is used for XDP_TX into the channel. It used to be a
part of the RQ, but with introduction of AF_XDP there will be one more
RQ that could share the same XDP SQ. This patch is a preparation for
that change.

Separate XDP_TX statistics per RQ were implemented in one of the previous
patches.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

net/mlx5e: Allow ICO SQ to be used by multiple RQs

Prepare to creation of the XSK RQ, which will require posting UMRs, too.
The same ICO SQ will be used for both RQs and also to trigger interrupts
by posting NOPs. UMR WQEs can't be reused any more. Optimization
introduced in commit ab966d7e4ff98 ("net/mlx5e: RX, Recycle buffer of
UMR WQEs") is reverted.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

linux/dim: Rename externally used net_dim members

Removed 'net' prefix from functions and structs used by external drivers.

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

linux/dim: Rename net_dim_sample() to net_dim_update_sample()

In order to avoid confusion between the function and the similarly
named struct.
In preparation for removing the 'net' prefix from dim members.

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Take HW interrupt trigger into a function

mlx5e_trigger_irq posts a NOP to the ICO SQ just to trigger an IRQ and
enter the NAPI poll on the right CPU according to the affinity. Use it
in mlx5e_activate_rq.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: XDP, Change the XDP SQ redirect indication

Do not maintain an SQ state bit to indicate whether an
XDP SQ serves redirect operations.

Instead, rely on the fact that such an XDP SQ doesn't reside
in an RQ instance, while the others do.
This info is not known to the XDP SQ functions themselves,
and they rely on their callers to distinguish between the cases.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Add support for XDP_REDIRECT in device-out side

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>

net/mlx5e: Move XDP related code into new XDP files

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>

net/mlx5e: Add channel events counter

Add per-channel and global ethtool counters for channel events.
Each event indicates an interrupt on one of the channel's
completion queues.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Add NAPI statistics

Add per-channel and global ethtool counters for NAPI.
This helps us monitor and analyze performance in general.

- ch[i]_poll:
the number of times the channel's NAPI poll was invoked.

- ch[i]_arm:
the number of times the channel's NAPI poll completed
and armed the completion queues.

- ch[i]_aff_change:
the number of times the channel's NAPI poll explicitly
stopped execution on a cpu due to a change in affinity.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Avoid reset netdev stats on configuration changes

Move all RQ, SQ and channel counters from the channel objects into the
priv structure. With this change, counters will not be reset upon
channel configuration changes.

Channel's statistics for SQs which are associated with TCs higher than
zero will be presented in ethtool -S, only for SQs which were opened at
least once since the module was loaded (regardless of their open/close
current status). This is done in order to decrease the total amount of
statistics presented and calculated for the common out of box use (no
QoS).

mlx5e_channel_stats is a compound of CH,RQ,SQs stats in order to
create locality for the NAPI when handling TX and RX of the same
channel.

Align the new statistics struct per ring to avoid several channels
update to the same cache line at the same time.
Packet rate was tested, no degradation sensed.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
CC: Qing Huang <qing.huang@oracle.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Remove MLX5E_TEST_BIT macro

MLX5E_TEST_BIT macro is the same as the already existent test_bit,
remove it and replace all usages.

Signed-off-by: Gal Pressman <galp@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Enable adaptive-TX moderation

Add support for adaptive TX moderation. This greatly reduces TX interrupt
rate and increases bandwidth, mostly for TCP bandwidth over ARM
architecture (below). There is a slight single stream TCP with very large
message sizes degradation (x86). In this case if there's any moderation on
transmitted packets the bandwidth would reduce due to hitting TCP output limit.
Since this is a synthetic case, this is still worth doing.

Performance improvement (ConnectX-4Lx 40GbE, ARM)
TCP 64B bandwidth with 1-50 streams increased 6-35%.
TCP 64B bandwidth with 100-500 streams increased 20-70%.

Performance improvement (ConnectX-5 100GbE, x86)
Bandwidth: increased up to 40% (1024B with 10s of streams).
Interrupt rate: reduced up to 50% (1024B with 1000s of streams).

Performance degradation (ConnectX-5 100GbE, x86)
Bandwidth: up to 10% decrease single stream TCP (1MB message size from
51Gb/s to 47Gb/s).

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dim: use struct net_dim_sample as arg to net_dim

Simplify the arguments net_dim() by formatting them into a struct
net_dim_sample before calling the function.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Suggested-by: Tal Gilboa <talgi@mellanox.com>
Acked-by: Tal Gilboa <talgi@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Change Mellanox references in DIM code

Change all appropriate mlx5_am* and MLX5_AM* references to net_dim and
NET_DIM, respectively, in code that handles dynamic interrupt
moderation. Also change all references from 'am' to 'dim' when used as
local variables and add generic profile references.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Acked-by: Tal Gilboa <talgi@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Remove rq references in mlx5e_rx_am

This makes mlx5e_am_sample more generic so that it can be called easily
from a driver that does not use the same data structure to store these
values in a single structure.

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Acked-by: Tal Gilboa <talgi@mellanox.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Fix napi poll with zero budget

napi->poll can be called with budget 0, e.g. in netpoll scenarios
where the caller only wants to poll TX rings
(poll_one_napi@net/core/netpoll.c).

The below commit changed RX polling from "while" loop to "do {} while",
which caused to ignore the initial budget and handle at least one RX
packet.

This fixes the following warning:
[ 2852.049194] mlx5e_napi_poll+0x0/0x260 [mlx5_core] exceeded budget in poll
[ 2852.049195] ------------[ cut here ]------------
[ 2852.049195] WARNING: CPU: 0 PID: 25691 at net/core/netpoll.c:171 netpoll_poll_dev+0x18a/0x1a0

Fixes: 4b7dfc992514 ("net/mlx5e: Early-return on empty completion queues")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Reported-by: Martin KaFai Lau <kafai@fb.com>
Tested-by: Martin KaFai Lau <kafai@fb.com>
Cc: kernel-team@fb.com
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Stop NAPI when irq balancer changes affinity

NAPI context keeps rescheduling on same CPU as long as it's busy.
This doesn't give the oppurtunity for changes in irq affinities
to take effect.
Fix that by calling napi_complete_done() upon a change in affinity.
This would stop the NAPI and reschedule it on the new CPU.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Use kernel's mechanism to avoid missing NAPIs

We used a channel state bit MLX5E_CHANNEL_NAPI_SCHED to make
sure no NAPI is missed when a channel's napi_schedule() is called
for completion events of the different channel's resources/rings
while NAPI is currently running.
Now, as similar mechanism is implemented in kernel,
("39e6c8208d7b net: solve a NAPI race"),
we obsolete our own implementation and rely on the return value
of napi_complete_done().

This patch removes a redundant overhead of atomic bit operations.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Type-specific optimizations for RX post WQEs function

Separate the RX post WQEs function of the different RQ types.
This enables RQ type-specific optimizations in data-path.

Poll the ICOSQ completion queue only for Striding RQ,
and only when a UMR post completion could be possibly available.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Non-atomic indicator for ring enabled state

Rings enabled state change occurs in control path only, and is always
followed by a napi_sychronize(), so that following NAPIs read the
new value. This read does not need to be atomic.

The RQ auto-moderation bit is not set/cleared in data-path.
No need for atomic read, a regular read operation is sufficient.
In RQ creation time as well, there's no multiple threads trying
to access it yet, hence a regular read can be used.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5: Make get_cqe routine not ethernet-specific

Move mlx5e_get_cqe routine to wq.h and rename it to
mlx5_cqwq_get_cqe.

This allows it to be used by other CQ users outside of the
ethernet driver code.

A later patch in this patchset will make use of it from
FPGA code for the FPGA high-speed connection.

Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Use u8 as ownership type in mlx5e_get_cqe()

CQE ownership indication is as small as a single bit.
Use u8 to speedup the comparison.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Cc: kernel-team@fb.com
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: Optimize poll ICOSQ completion queue

UMR operations are more frequent and important.
Check them first, and add a compiler branch predictor hint.

According to current design, ICOSQ CQ can contain at most one
pending CQE per napi. Poll function is optimized accordingly.

Performance:
Single-stream packet-rate tested with pktgen.
Packets are dropped in tc level to zoom into driver data-path.
Larger gain is expected for larger packet sizes, as BW is higher
and UMR posts are more frequent.

---------------------------------------------
packet size | before | after | gain |
64B | 4,092,370 | 4,113,306 | 0.5% |
1024B | 3,421,435 | 3,633,819 | 6.2% |

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Cc: kernel-team@fb.com
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

net/mlx5e: CQ and RQ don't need priv pointer

Remove mlx5e_priv pointer from CQ and RQ structs,
it was needed only to access mdev pointer from priv pointer.

Instead we now pass mdev where needed.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>

net/mlx5e: Different SQ types

Different SQ types (tx, xdp, ico) are growing apart, we separate them
and remove unwanted parts in each one of them, to simplify data path and
utilize data cache.

Remove DB union from SQ structures since it is not needed anymore as we
now have different SQ data type for each SQ.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Poll XDP TX CQ before RX CQ

Handle XDP TX completions before handling RX packets, to make sure more
free space is available for XDP TX packets a moment before handling
RX packets.

Performance improvement:
System: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz

Test case Before Now improvement
---------------------------------------------------------------
XDP Drop (1 core) 16.9Mpps 16.9Mpps No change
XDP TX (1 core) 12Mpps 13Mpps 8%

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Move XDP SQ instance into RQ

To save many rq->channel->sq dereferences in fast-path.
And rename it to xdpsq.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Move XDP completion functions to rx file

XDP code belongs to RX path, move mlx5e_poll_xdp_tx_cq and
mlx5e_free_xdp_tx_descs to en_rx.c.

Rename them to mlx5e_poll_xdpsq_cq and mlx5e_free_xdpsq_descs.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Use dma_rmb rather than rmb in CQE fetch routine

Use dma_rmb in mlx5e_get_cqe rather than aggressive rmb (at least on
some architectures), this should help improve the performance on such
CPU archs where dma_rmb is optimized.

Performance improvement:
System: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz

Test case Baseline Now improvement
---------------------------------------------------------------
TX packets (24 threads) 45Mpps 50Mpps 11%
TC stack Drop (1 core) 3.45Mpps 3.6Mpps 5%
XDP Drop (1 core) 14Mpps 16.9Mpps 20%
XDP TX (1 core) 10.4Mpps 12Mpps 15%

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Change the SQ/RQ operational state to positive logic

When using the negative logic (i.e. FLUSH state), after the RQ/SQ reopen
we will have a time interval that the RQ/SQ is not really ready and the
state indicates that its not in FLUSH state because the initial SQ/RQ struct
memory starts as zeros.
Now we changed the state to indicate if the SQ/RQ is opened and we will
set the READY state after finishing preparing all the SQ/RQ resources.

Fixes: 6e8dd6d6f4bd ("net/mlx5e: Don't wait for SQ completions on close")
Fixes: f2fde18c52a7 ("net/mlx5e: Don't wait for RQ completions on close")
Signed-off-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: XDP TX forwarding support

Adding support for XDP_TX forwarding from xdp program.
Using XDP, now user can loop packets out of the same port.

We create a dedicated TX SQ for each channel that will serve
XDP programs that return XDP_TX action to loop packets back to
the wire directly from the channel RQ RX path.

For that RX pages will now need to be mapped bi-directionally,
and on XDP_TX action we will sync the page back to device then
queue it into SQ for transmission. The XDP xmit frame function will
report back to the RX path if the page was consumed (transmitted), if so,
RX path will forget about that page as if it were released to the stack.
Later on, on XDP TX completion, the page will be released back to the
page cache.

For simplicity this patch will hit a doorbell on every XDP TX packet.

Next patch will introduce a xmit more like mechanism that will
queue up more than one packet into SQ w/o notifying the hardware,
once RX napi loop is done we will hit doorbell once for all XDP TX
packets form the previous loop. This should drastically improve
XDP TX performance.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Have a clear separation between different SQ types

Make a clear separate between Regular SQ (TXQ) and ICO SQ creation,
destruction and union their mutual information structures.

Don't allocate redundant TXQ skb/wqe_info/dma_fifo arrays for ICO SQ.
And have a different SQ edge for ICO SQ than TXQ SQ, to be more
accurate.

In preparation for XDP TX support.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Single flow order-0 pages for Striding RQ

To improve the memory consumption scheme, we omit the flow that
demands and splits high-order pages in Striding RQ, and stay
with a single Striding RQ flow that uses order-0 pages.

Moving to fragmented memory allows the use of larger MPWQEs,
which reduces the number of UMR posts and filler CQEs.

Moving to a single flow allows several optimizations that improve
performance, especially in production servers where we would
anyway fallback to order-0 allocations:
- inline functions that were called via function pointers.
- improve the UMR post process.

This patch alone is expected to give a slight performance reduction.
However, the new memory scheme gives the possibility to use a page-cache
of a fair size, that doesn't inflate the memory footprint, which will
dramatically fix the reduction and even give a performance gain.

Performance tests:
The following results were measured on a freshly booted system,
giving optimal baseline performance, as high-order pages are yet to
be fragmented and depleted.

We ran pktgen single-stream benchmarks, with iptables-raw-drop:

Single stride, 64 bytes:
* 4,739,057 - baseline
* 4,749,550 - this patch
no reduction

Larger packets, no page cross, 1024 bytes:
* 3,982,361 - baseline
* 3,845,682 - this patch
3.5% reduction

Larger packets, every 3rd packet crosses a page, 1500 bytes:
* 3,731,189 - baseline
* 3,579,414 - this patch
4% reduction

Fixes: 461017cb006a ("net/mlx5e: Support RX multi-packet WQE (Striding RQ)")
Fixes: bc77b240b3c5 ("net/mlx5e: Add fragmented memory support for RX multi packet WQE")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Don't wait for SQ completions on close

Instead of asking the firmware to flush the SQ (Send Queue) via
asynchronous completions when moved to error, we handle SQ flush
manually (mlx5e_free_tx_descs) same as we did when SQ flush got
timed out or on tx_timeout.

This will reduce SQs flush time and speedup interface down procedure.

Moved mlx5e_free_tx_descs to the end of en_tx.c for tx
critical code locality.

Fixes: 29429f3300a3 ('net/mlx5e: Timeout if SQ doesn't flush during close')
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Support adaptive RX coalescing

Striving for high message rate and low interrupt rate.

Usage:
ethtool -C <interface> adaptive-rx on/off

Signed-off-by: Gil Rockah <gilr@mellanox.com>
Signed-off-by: Achiad Shochat <achiad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
CC: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Remove redundant barrier

The bit-op operation one line before is an explicit barrier
by itself.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Add fragmented memory support for RX multi packet WQE

If the allocation of a linear (physically continuous) MPWQE fails,
we allocate a fragmented MPWQE.

This is implemented via device's UMR (User Memory Registration)
which allows to register multiple memory fragments into ConnectX
hardware as a continuous buffer.
UMR registration is an asynchronous operation and is done via
ICO SQs.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Added ICO SQs

Added ICO (Internal Control Operations) SQ per channel to be used
for driver internal operations such as memory registration for
fragmented memory and nop requests upon ifconfig up.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlx5: use napi_consume_skb API to get bulk free operations

Bulk free of SKBs happen transparently by the API call napi_consume_skb().
The napi budget parameter is needed by napi_consume_skb() to detect
if called from netpoll.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Remove wrong poll CQ optimization

With the MLX5E_CQ_HAS_CQES optimization flag, the following buggy
flow might occur:
- Suppose RX is always busy, TX has a single packet every second.
- We poll a single TX cqe and clear its flag.
- We never arm it again as RX is always busy.
- TX CQ flag is never changed, and new TX cqes are not polled.

We revert this optimization.

Fixes: e586b3b0baee ('net/mlx5: Ethernet Datapath files')
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlx5: support napi_complete_done()

A NAPI poll handler should return number of RX packets processed,
instead of 0 / budget.

This allows proper busy poll accounting through LINUX_MIB_BUSYPOLLRXPACKETS
SNMP counter.

napi_complete_done() allows /sys/class/net/ethX/gro_flush_timeout
to be used for finer GRO aggregation control.

Tested:

Enabled busy polling, and checked TcpExtBusyPollRxPackets counter is increasing.

echo 70 >/proc/sys/net/core/busy_read
nstat >/dev/null
netperf -H target -t TCP_RR >/dev/null
nstat | grep TcpExtBusyPollRxPackets
TcpExtBusyPollRxPackets 490958 0.0

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eli Cohen <eli@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Pop cq outside mlx5e_get_cqe

Separate between mlx5e_get_cqe() and mlx5_cqwq_pop(), this helps for
better code readability and better CQ buffer management.

Signed-off-by: Achiad Shochat <achiad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5e: Remove mlx5e_cq.sqrq back-pointer

Use container_of() instead.

Signed-off-by: Achiad Shochat <achiad@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mlx5: Ethernet Datapath files

en_[rt]x.c contains the data path related code specific to tx or rx.
en_txrx.c contains data path code which is common for both the rx and
tx, this is mainly napi related code.

Below are the objects that are being used by the hardware and the driver
in the data path:

Channel - one channel per IRQ. Every channel object contains:
RQ - describes the rx queue
TIR - One TIR (Transport Interface Receive) object per flow type. TIR
contains attributes for a type of rx flow (e.g IPv4, IPv6 etc).
A flow is defined in the Flow Table.
Currently TIR describes the RSS hash parameters if exists and LRO
attributes.
SQ - describes the a tx queue. There is one SQ (Send Queue) per
TC (traffic class).
TIS - There is one TIS (Transport Interface Send) per TC. It
describes the TC and may later be extended to describe more
transport properties.

Both RQ and SQ inherit from the object WQ (work queue). This common code
to describe the layout of CQE's WQE's in memory is in the files wq.[cj]

For every channel there is one NAPI context that is used for RX and
for TX.

Driver is using netdev_alloc_skb() to allocate skb's.

Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>