Use page pool for RX buffer handling. Makes RX path more efficient and
is required prework for future XDP support.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Received Ethernet frames are assigned to first RX queue per default.
Based on EtherType Ethernet frames can be assigned to other RX queues.
This enables processing of real-time Ethernet protocols on dedicated
RX queues.

Add RX flow classification interface for EtherType based RX queue
assignment.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Support additional TX/RX queue pairs if dedicated interrupt is
available. Interrupts are detected by name in device tree.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For multiple queues multiple interrupts shall be used. Therefore, rework
global interrupt to per queue interrupt.

Every interrupt name shall contain interface name and queue information.
To get a valid interface name, the interrupt request needs to by done
during open like in other drivers. Additionally, this allows the removal
of some initialisation checks in the interrupt handler.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Additional TX/RX queue pairs require dedicated interrupts. Extend
binding with additional interrupts.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Within SoCs like ZynqMP, FPGA logic can be connected to different kinds
of AXI master ports. Also cache coherent AXI master ports are available.
The property "dma-coherent" is used to signal that DMA is cache
coherent.

Add "dma-coherent" property to allow the configuration of cache coherent
DMA.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tony Nguyen says:

====================
Intel Wired LAN Driver Updates 2022-09-28 (ice)

Arkadiusz implements a single pin initialization function, checking feature
bits, instead of having separate device functions and updates sub-device
IDs for recognizing E810T devices.

Martyna adds support for switchdev filters on VLAN priority field.

* '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue:
  ice: Add support for VLAN priority filters in switchdev
  ice: support features on new E810T variants
  ice: Merge pin initialization of E810 and E810T adapters
====================

Link: https://lore.kernel.org/r/20220928203217.411078-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the value
to be returned to user space.
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/1664364860-29153-1-git-send-email-wangyufen@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Vladimir Oltean says:

====================
Add tc-taprio support for queueMaxSDU

The tc-taprio offload mode supported by the Felix DSA driver has
limitations surrounding its guard bands.

The initial discussion was at:
https://lore.kernel.org/netdev/c7618025da6723418c56a54fe4683bd7@walle.cc/

with the latest status being that we now have a vsc9959_tas_guard_bands_update()
method which makes a best-guess attempt at how much useful space to
reserve for packet scheduling in a taprio interval, and how much to
reserve for guard bands.

IEEE 802.1Q actually does offer a tunable variable (queueMaxSDU) which
can determine the max MTU supported per traffic class. In turn we can
determine the size we need for the guard bands, depending on the
queueMaxSDU. This way we can make the guard band of small taprio
intervals smaller than one full MTU worth of transmission time, if we
know that said traffic class will transport only smaller packets.

As discussed with Gerhard Engleder, the queueMaxSDU may also be useful
in limiting the latency on an endpoint, if some of the TX queues are
outside of the control of the Linux driver.
https://patchwork.kernel.org/project/netdevbpf/patch/20220914153303.1792444-11-vladimir.oltean@nxp.com/

Allow input of queueMaxSDU through netlink into tc-taprio, offload it to
the hardware I have access to (LS1028A), and (implicitly) deny
non-default values to everyone else. Kurt Kanzenbach has also kindly
tested and shared a patch to offload this to hellcreek.

v3 at:
https://patchwork.kernel.org/project/netdevbpf/cover/20220927234746.1823648-1-vladimir.oltean@nxp.com/
v2 at:
https://patchwork.kernel.org/project/netdevbpf/list/?series=679954&state=*
v1 at:
https://patchwork.kernel.org/project/netdevbpf/cover/20220914153303.1792444-1-vladimir.oltean@nxp.com/
====================

Link: https://lore.kernel.org/r/20220928095204.2093716-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The driver currently sets the PTCMSDUR register statically to the max
MTU supported by the interface. Keep this logic if tc-taprio is absent
or if the max_sdu for a traffic class is 0, and follow the requested max
SDU size otherwise.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The Port Time Gating Control Register (PTGCR) and Port Time Gating
Capability Register (PTGCAPR) have definitions in the driver which
aren't in line with the other registers. Rename these.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The &priv->si->hw construct dereferences 2 pointers and makes lines
longer than they need to be, in turn making the code harder to read.

Replace &priv->si->hw accesses with a "hw" variable when there are 2 or
more accesses within a function that dereference this. This includes
loops, since &priv->si->hw is a loop invariant.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add support for configuring the max SDU per priority and per port. If not
specified, keep the default.
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The following patch will need to make this function also respond to
TC_QUERY_BASE, so make the processing more structured around the
tc_setup_type.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Our current vsc9959_tas_guard_bands_update() algorithm has a limitation
imposed by the hardware design. To avoid packet overruns between one
gate interval and the next (which would add jitter for scheduled traffic
in the next gate), we configure the switch to use guard bands. These are
as large as the largest packet which is possible to be transmitted.

The problem is that at tc-taprio intervals of sizes comparable to a
guard band, there isn't an obvious place in which to split the interval
between the useful portion (for scheduling) and the guard band portion
(where scheduling is blocked).

For example, a 10 us interval at 1Gbps allows 1225 octets to be
transmitted. We currently split the interval between the bare minimum of
33 ns useful time (required to schedule a single packet) and the rest as
guard band.

But 33 ns of useful scheduling time will only allow a single packet to
be sent, be that packet 1200 octets in size, or 60 octets in size. It is
impossible to send 2 60 octets frames in the 10 us window. Except that
if we reduced the guard band (and therefore the maximum allowable SDU
size) to 5 us, the useful time for scheduling is now also 5 us, so more
packets could be scheduled.

The hardware inflexibility of not scheduling according to individual
packet lengths must unfortunately propagate to the user, who needs to
tune the queueMaxSDU values if he wants to fit more small packets into a
10 us interval, rather than one large packet.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

IEEE 802.1Q clause 12.29.1.1 "The queueMaxSDUTable structure and data
types" and 8.6.8.4 "Enhancements for scheduled traffic" talk about the
existence of a per traffic class limitation of maximum frame sizes, with
a fallback on the port-based MTU.

As far as I am able to understand, the 802.1Q Service Data Unit (SDU)
represents the MAC Service Data Unit (MSDU, i.e. L2 payload), excluding
any number of prepended VLAN headers which may be otherwise present in
the MSDU. Therefore, the queueMaxSDU is directly comparable to the
device MTU (1500 means L2 payload sizes are accepted, or frame sizes of
1518 octets, or 1522 plus one VLAN header). Drivers which offload this
are directly responsible of translating into other units of measurement.

To keep the fast path checks optimized, we keep 2 arrays in the qdisc,
one for max_sdu translated into frame length (so that it's comparable to
skb->len), and another for offloading and for dumping back to the user.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

When adding optional new features to Qdisc offloads, existing drivers
must reject the new configuration until they are coded up to act on it.

Since modifying all drivers in lockstep with the changes in the Qdisc
can create problems of its own, it would be nice if there existed an
automatic opt-in mechanism for offloading optional features.

Jakub proposes that we multiplex one more kind of call through
ndo_setup_tc(): one where the driver populates a Qdisc-specific
capability structure.

First user will be taprio in further changes. Here we are introducing
the definitions for the base functionality.

Link: https://patchwork.kernel.org/project/netdevbpf/patch/20220923163310.3192733-3-vladimir.oltean@nxp.com/Suggested-by: Jakub Kicinski <kuba@kernel.org>
Co-developed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

After commit 09b5678c("tipc: remove dead code in tipc_net and relatives"),
struct distr_queue_item is not used any more and can be removed as well.
Signed-off-by: Yuan Can <yuancan@huawei.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Link: https://lore.kernel.org/r/20220928085636.71749-1-yuancan@huawei.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

After commit 3226b158 ("net: avoid 32 x truesize under-estimation
for tiny skbs") we are observing 10-20% regressions in performance
tests with small packets. The perf trace points to high pressure on
the slab allocator.

This change tries to improve the allocation schema for small packets
using an idea originally suggested by Eric: a new per CPU page frag is
introduced and used in __napi_alloc_skb to cope with small allocation
requests.

To ensure that the above does not lead to excessive truesize
underestimation, the frag size for small allocation is inflated to 1K
and all the above is restricted to build with 4K page size.

Note that we need to update accordingly the run-time check introduced
with commit fd9ea57f ("net: add napi_get_frags_check() helper").

Alex suggested a smart page refcount schema to reduce the number
of atomic operations and deal properly with pfmemalloc pages.

Under small packet UDP flood, I measure a 15% peak tput increases.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Suggested-by: Alexander H Duyck <alexanderduyck@fb.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Link: https://lore.kernel.org/r/6b6f65957c59f86a353fc09a5127e83a32ab5999.1664350652.git.pabeni@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

To work around a misbehavior of the compiler's ability to see into
composite flexible array structs (as detailed in the coming memcpy()
hardening series[1]), use unsafe_memcpy(), as the sizing,
bounds-checking, and allocation are all very tightly coupled here.
This silences the false-positive reported by syzbot:

  memcpy: detected field-spanning write (size 80) of single field "&n->sel" at net/sched/cls_u32.c:1043 (size 16)

[1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Reported-by: syzbot+a2c4601efc75848ba321@syzkaller.appspotmail.com
Link: https://lore.kernel.org/lkml/000000000000a96c0b05e97f0444@google.com/Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20220927153700.3071688-1-keescook@chromium.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The stmmac-axi-config subnode is present in multiple dwmac instance DTs,
document its content per snps,axi-config property description which is
a phandle to this subnode.
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220927012449.698915-1-marex@denx.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

nlmsg_flags are full of historical baggage, inconsistencies and
strangeness. Try to document it more thoroughly. Explain the meaning
of the ECHO flag (and while at it clarify the comment in the uAPI).
Handwave a little about the NEW request flags and how they make
sense on the surface but cater to really old paradigm before commands
were a thing.

I will add more notes on how to make use of ECHO and discouragement
for reuse of flags to the kernel-side documentation.

Link: https://lore.kernel.org/r/20220927212306.823862-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

No conflicts.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking fixes from Paolo Abeni:
 "Including fixes from wifi and can.

  Current release - regressions:

   - phy: don't WARN for PHY_UP state in mdio_bus_phy_resume()

   - wifi: fix locking in mac80211 mlme

   - eth:
      - revert "net: mvpp2: debugfs: fix memory leak when using debugfs_lookup()"
      - mlxbf_gige: fix an IS_ERR() vs NULL bug in mlxbf_gige_mdio_probe

  Previous releases - regressions:

   - wifi: fix regression with non-QoS drivers

  Previous releases - always broken:

   - mptcp: fix unreleased socket in accept queue

   - wifi:
      - don't start TX with fq->lock to fix deadlock
      - fix memory corruption in minstrel_ht_update_rates()

   - eth:
      - macb: fix ZynqMP SGMII non-wakeup source resume failure
      - mt7531: only do PLL once after the reset
      - usbnet: fix memory leak in usbnet_disconnect()

  Misc:

   - usb: qmi_wwan: add new usb-id for Dell branded EM7455"

* tag 'net-6.0-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (30 commits)
  mptcp: fix unreleased socket in accept queue
  mptcp: factor out __mptcp_close() without socket lock
  net: ethernet: mtk_eth_soc: fix mask of RX_DMA_GET_SPORT{,_V2}
  net: mscc: ocelot: fix tagged VLAN refusal while under a VLAN-unaware bridge
  can: c_can: don't cache TX messages for C_CAN cores
  ice: xsk: drop power of 2 ring size restriction for AF_XDP
  ice: xsk: change batched Tx descriptor cleaning
  net: usb: qmi_wwan: Add new usb-id for Dell branded EM7455
  selftests: Fix the if conditions of in test_extra_filter()
  net: phy: Don't WARN for PHY_UP state in mdio_bus_phy_resume()
  net: stmmac: power up/down serdes in stmmac_open/release
  wifi: mac80211: mlme: Fix double unlock on assoc success handling
  wifi: mac80211: mlme: Fix missing unlock on beacon RX
  wifi: mac80211: fix memory corruption in minstrel_ht_update_rates()
  wifi: mac80211: fix regression with non-QoS drivers
  wifi: mac80211: ensure vif queues are operational after start
  wifi: mac80211: don't start TX with fq->lock to fix deadlock
  wifi: cfg80211: fix MCS divisor value
  net: hippi: Add missing pci_disable_device() in rr_init_one()
  net/mlxbf_gige: Fix an IS_ERR() vs NULL bug in mlxbf_gige_mdio_probe
  ...

Pull input fixes from Dmitry Torokhov:

 - small fixes for iqs62x-keys and melfas_mip4 drivers

 - corrected register address in snvs_pwrkey driver

 - Synaptic driver will stop trying to use intertouch (native) mode on
   some Lenovo AMD devices

* tag 'input-for-v6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: snvs_pwrkey - fix SNVS_HPVIDR1 register address
  Input: synaptics - disable Intertouch for Lenovo T14 and P14s AMD G1
  Input: iqs62x-keys - drop unused device node references
  Input: melfas_mip4 - fix return value check in mip4_probe()

Pull ATA fixes from Damien Le Moal:
 "Three late patches to fix problems discovered recently:

   - Add a horkage to disable link power management by default for the
     Pioneer BDR-207M and BDR-205 DVD drives (from Niklas)

   - Two patches to fix setting the maximum queue depth of libsas owned
     ATA devices (from me)"

* tag 'ata-6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: libata-sata: Fix device queue depth control
  ata: libata-scsi: Fix initialization of device queue depth
  libata: add ATA_HORKAGE_NOLPM for Pioneer BDR-207M and BDR-205

Merge tag 'loongarch-fixes-6.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Some trivial fixes and cleanup"

* tag 'loongarch-fixes-6.0-3' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Clean up loongson3_smp_ops declaration
  LoongArch: Fix and cleanup csr_era handling in do_ri()
  LoongArch: Align the address of kernel_entry to 4KB

Add __init/__exit annotations to module init/exit funcs
Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220928031708.89120-1-ruanjinjie@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

The 'mem' returned by platform_get_resource() has been checked in probe
function, so it is no need do this check in remove function.
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220927151406.797800-1-yangyingliang@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Use skb_put_data() instead of skb_put() and memcpy(), which is clear.
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Link: https://lore.kernel.org/r/20220927141835.19221-1-shangxiaojing@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

After commit 6870957e("liquidio: make soft command calls synchronous"), no
one use struct lio_trusted_vf_ctx, so remove it.
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20220927133940.104181-1-yuancan@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.
No functional change.
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Link: https://lore.kernel.org/r/20220927111925.2424100-1-liushixin2@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Use skb_put_data() instead of skb_put() and memcpy(), which is clear.
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Link: https://lore.kernel.org/r/20220927024511.14665-1-shangxiaojing@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Use skb_put_data() instead of skb_put() and memcpy(), which is clear.
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Link: https://lore.kernel.org/r/20220927023043.17769-1-shangxiaojing@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Use skb_put_data() instead of skb_put() and memcpy(), which is shorter
and clear. Drop the tmp variable that is not needed any more.
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Link: https://lore.kernel.org/r/20220927022802.16050-1-shangxiaojing@huawei.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Saeed Mahameed says:

====================
mlx5-updates-2022-09-27

This is Part #1 of 4 parts series to align mlx5's implementation of
XSK (AF_XDP) RX-Qs indexing and management with other vendors:

Maxim Says:
===========

xsk: Bug fixes for frame mapping on striding RQ

Striding RQ relies on the driver mapping RX buffers into the NIC's
virtual memory space. Currently, regadless of the XSK frame size, mlx5e
maps them using MTT, and each mapping's length is PAGE_SIZE. As the
result, the stride size used by striding RQ is also equal to PAGE_SIZE.

This decision has the following issues:

1. In the XSK aligned mode with frame size smaller than PAGE_SIZE, it's
suboptimal. Using 2K strides and 2K pages allows to post twice as fewer
WQEs.

2. MTT is not suitable for unaligned frames, as it requires natural
alignment theoretically, in practice at least 8-byte alignment.

3. Using mapping and stride bigger than the frame has risk of writing
over the bounds of the XSK frame upon receiving packets bigger than MTU,
which is possible in some specific configurations.

This series addresses issues 1 and 2 and alleviates issue 3. Where
possible, page and stride size will match the XSK frame size (firmware
upgrade may be needed to have effect for 2K frames). Unaligned mode will
use KSM instead of MTT, which allows to drop the partial workaround [1].

[1]: https://lore.kernel.org/netdev/YufYFQ6JN91lQbso@boxer/T/
====================

Link: https://lore.kernel.org/r/20220927203611.244301-1-saeed@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Some of the parameters of striding RQ are compile-time constants, but
they are going to become dynamically calculated at runtime in a
following commit. This commit prepares the datapath to take cached
runtime parameters, prefilled at queue creation.

New fields added to struct mlx5e_rq fit into an existing 7-byte hole.
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

This commit moves the dma_info array to the end of struct mlx5e_mpw_info
to make it a flexible array. It also removes the intermediate struct
mlx5e_umr_dma_info, which used to contain only this array. The
flexibility of dma_info will allow to choose its size dynamically in a
following commit.
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Normally, the MTU change requires reopening the channels, but it can be
skipped if the new MTU doesn't change any of the queue parameters and if
MTU is not used in the data path.

The shortcut is applicable to the non-linear mode of striding RQ,
because the only thing affected by MTU is the queue length. As ethtool
sets the queue length in packets, but striding RQ length is defined in
strides or bytes, we estimate the RQ length to be at least as big as the
requested number of MTU-sized packets, that's why it depends on MTU.

Improve the shortcut by actually checking whether the RQ length stayed
the same, instead of an intermediate step in the calculation.

As MTU also affects the SHAMPO parameters, skip the shortcut if SHAMPO
is in use.
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In a typical scenario, if an XSK socket is opened first, then an XDP
program is attached, mlx5e_validate_xsk_param will be called twice:
first on XSK bind, second on channel restart caused by enabling XDP. The
validation includes a call to mlx5e_rx_is_linear_skb, which checks the
presence of the XDP program.

The above means that mlx5e_rx_is_linear_skb might return true the first
time, but false the second time, as mlx5e_rx_get_linear_sz_skb's return
value will increase, because of a different headroom used with XDP.

As XSK RQs never exist without XDP, it would make sense to trick
mlx5e_rx_get_linear_sz_skb into thinking XDP is enabled at the first
check as well. This way, if MTU is too big, it would be detected on XSK
bind, without giving false hope to the userspace application.

However, it turns out that this check is too restrictive in the first
place. SKBs created on XDP_PASS on XSK RQs don't have any headroom. That
means that big MTUs filtered out on the first and the second checks
might actually work.

So, address this issue in the proper way, but taking into account the
absence of the SKB headroom on XSK RQs, when calculating the buffer
size.
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>