Add support for forcing the link speed and duplex setting in the
pcs_link_up() method for out of band modes, which will be useful when
we finish converting the pcs_config() method. Until then, we still have
to force duplex for 802.3z modes to work correctly.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

mtk_sgmii does a lot of read-modify-write operations, for which there
is a specific regmap function. Use this function instead of open-coding
the operations.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add a pcs_get_state() implementation which uses the advertisements
to compute the resulting link modes, and BMSR contents to determine
negotiation and link status.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The functions called by the pcs_config() method always return zero, so
there is no point trying to handle an error from these functions. Make
these functions void, eliminate the "err" variable and simply return
zero from the pcs_config() function itself.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As a result of help from Frank Wunderlich to investigate and test, we
know a bit more about the PCS on the Mediatek platforms. Update the
definitions from this investigation.

This PCS appears similar, but not identical to the Lynx PCS.

Although not included in this patch, but for future reference, the PHY
ID registers at offset 4 read as 0x4d544950 'MTIP'.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add a helper to convert the PHY interface mode to the required link
timer setting as stated by the appropriate standard. Inappropriate
interface modes return an error.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Sebastian Andrzej Siewior says:

====================
net: Remove the obsolte u64_stats_fetch_*_irq()

This is the removal of u64_stats_fetch_*_irq() users in networking. The
prerequisites are part of v6.1-rc1.

The spi and bpf bits are not part of the series and have been routed
directly.
====================

Link: https://lore.kernel.org/r/20221026132215.696950-1-bigeasy@linutronix.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Now that the 32bit UP oddity is gone and 32bit uses always a sequence
count, there is no need for the fetch_irq() variants anymore.

Convert to the regular interface.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Now that the 32bit UP oddity is gone and 32bit uses always a sequence
count, there is no need for the fetch_irq() variants anymore.

Convert to the regular interface.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

====================
pull-request: wireless-next-2022-10-28

First set of patches v6.2. mac80211 refactoring continues for Wi-Fi 7.
All mac80211 driver are now converted to use internal TX queues, this
might cause some regressions so we wanted to do this early in the
cycle.

Note: wireless tree was merged[1] to wireless-next to avoid some
conflicts with mac80211 patches between the trees. Unfortunately there
are still two smaller conflicts in net/mac80211/util.c which Stephen
also reported[2]. In the first conflict initialise scratch_len to
"params->scratch_len ?: 3 * params->len" (note number 3, not 2!) and
in the second conflict take the version which uses elems->scratch_pos.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git/commit/?id=dfd2d876b3fda1790bc0239ba4c6967e25d16e91
[2] https://lore.kernel.org/all/20221020032340.5cf101c0@canb.auug.org.au/

mac80211
 - preparation for Wi-Fi 7 Multi-Link Operation (MLO) continues
 - add API to show the link STAs in debugfs
 - all mac80211 drivers are now using mac80211 internal TX queues (iTXQs)

rtw89
 - support 8852BE

rtl8xxxu
 - support RTL8188FU

brmfmac
 - support two station interfaces concurrently

bcma
 - support SPROM rev 11
====================

Link: https://lore.kernel.org/r/20221028132943.304ECC433B5@smtp.kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Because we enable the clock immediately after acquiring it in probe,
we can combine the 2 operations and use devm_clk_get_optional_enabled()
helper.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jiawen Wu says:

====================
net: WangXun txgbe ethernet driver

This patch series adds support for WangXun 10 gigabit NIC, to initialize
hardware, set mac address, and register netdev.

Change log:
v6: address comments:
    Jakub Kicinski: check with scripts/kernel-doc
v5: address comments:
    Jakub Kicinski: clean build with W=1 C=1
v4: address comments:
    Andrew Lunn: https://lore.kernel.org/all/YzXROBtztWopeeaA@lunn.ch/
v3: address comments:
    Andrew Lunn: remove hw function ops, reorder functions, use BIT(n)
                 for register bit offset, move the same code of txgbe
                 and ngbe to libwx
v2: address comments:
    Andrew Lunn: https://lore.kernel.org/netdev/YvRhld5rD%2FxgITEg@lunn.ch/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add MAC address related operations, and register netdev.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reset and initialize the hardware by configuring the MAC layer.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Get PCI config space info, set LAN id and check flash status.
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Mubashir Adnan Qureshi says:

====================
net: Add PLB functionality to TCP

This patch series adds PLB (Protective Load Balancing) to TCP and hooks
it up to DCTCP. PLB is disabled by default and can be enabled using
relevant sysctls and support from underlying CC.

PLB (Protective Load Balancing) is a host based mechanism for load
balancing across switch links. It leverages congestion signals(e.g. ECN)
from transport layer to randomly change the path of the connection
experiencing congestion. PLB changes the path of the connection by
changing the outgoing IPv6 flow label for IPv6 connections (implemented
in Linux by calling sk_rethink_txhash()). Because of this implementation
mechanism, PLB can currently only work for IPv6 traffic. For more
information, see the SIGCOMM 2022 paper:
  https://doi.org/10.1145/3544216.3544226
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

rcv_wnd can be useful to diagnose TCP performance where receiver window
becomes the bottleneck. rehash reports the PLB and timeout triggered
rehash attempts by the TCP connection.
Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A u32 counter is added to tcp_sock for counting the number of PLB
triggered rehashes for a TCP connection. An SNMP counter is also
added to count overall PLB triggered rehash events for a host. These
counters are hooked up to PLB implementation for DCTCP.

TCP_NLA_REHASH is added to SCM_TIMESTAMPING_OPT_STATS that reports
the rehash attempts triggered due to PLB or timeouts. This gives
a historical view of sustained congestion or timeouts experienced
by the TCP connection.
Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

PLB support is added to TCP DCTCP code. As DCTCP uses ECN as the
congestion signal, PLB also uses ECN to make decisions whether to change
the path or not upon sustained congestion.
Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Congestion control algorithms track PLB state and cause the connection
to trigger a path change when either of the 2 conditions is satisfied:

- No packets are in flight and (# consecutive congested rounds >=
  sysctl_tcp_plb_idle_rehash_rounds)
- (# consecutive congested rounds >= sysctl_tcp_plb_rehash_rounds)

A round (RTT) is marked as congested when congestion signal
(ECN ce_ratio) over an RTT is greater than sysctl_tcp_plb_cong_thresh.
In the event of RTO, PLB (via tcp_write_timeout()) triggers a path
change and disables congestion-triggered path changes for random time
between (sysctl_tcp_plb_suspend_rto_sec, 2*sysctl_tcp_plb_suspend_rto_sec)
to avoid hopping onto the "connectivity blackhole". RTO-triggered
path changes can still happen during this cool-off period.
Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

PLB (Protective Load Balancing) is a host based mechanism for load
balancing across switch links. It leverages congestion signals(e.g. ECN)
from transport layer to randomly change the path of the connection
experiencing congestion. PLB changes the path of the connection by
changing the outgoing IPv6 flow label for IPv6 connections (implemented
in Linux by calling sk_rethink_txhash()). Because of this implementation
mechanism, PLB can currently only work for IPv6 traffic. For more
information, see the SIGCOMM 2022 paper:
  https://doi.org/10.1145/3544216.3544226

This commit adds new sysctl knobs and sets their default values for
TCP PLB.
Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Raju Lakkaraju says:

====================
net: phy: mxl-gpy: Add MDI-X

This patch series add the MDI-X feature to GPY211 PHYs and
Also Change return type to gpy_update_interface() function
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for MDI-X status and configuration for GPY211 chips
Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

gpy_update_interface() is called from gpy_read_status() which does
return error codes. gpy_read_status() would benefit from returning
-EINVAL, etc.
Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

1) Move struct nft_payload_set definition to .c file where it is
   only used.

2) Shrink transport and inner header offset fields in the nft_pktinfo
   structure to 16-bits, from Florian Westphal.

3) Get rid of nft_objref Kbuild toggle, make it built-in into
   nf_tables. This expression is used to instantiate conntrack helpers
   in nftables. After removing the conntrack helper auto-assignment
   toggle it this feature became more important so move it to the nf_tables
   core module. Also from Florian.

4) Extend the existing function to calculate payload inner header offset
   to deal with the GRE and IPIP transport protocols.

6) Add inner expression support for nf_tables. This new expression
   provides a packet parser for tunneled packets which uses a userspace
   description of the expected inner headers. The inner expression
   invokes the payload expression (via direct call) to match on the
   inner header protocol fields using the inner link, network and
   transport header offsets.

   An example of the bytecode generated from userspace to match on
   IP source encapsulated in a VxLAN packet:

   # nft --debug=netlink add rule netdev x y udp dport 4789 vxlan ip saddr 1.2.3.4
     netdev x y
       [ meta load l4proto => reg 1 ]
       [ cmp eq reg 1 0x00000011 ]
       [ payload load 2b @ transport header + 2 => reg 1 ]
       [ cmp eq reg 1 0x0000b512 ]
       [ inner type vxlan hdrsize 8 flags f [ meta load protocol => reg 1 ] ]
       [ cmp eq reg 1 0x00000008 ]
       [ inner type vxlan hdrsize 8 flags f [ payload load 4b @ network header + 12 => reg 1 ] ]
       [ cmp eq reg 1 0x04030201 ]

7) Store inner link, network and transport header offsets in percpu
   area to parse inner packet header once only. Matching on a different
   tunnel type invalidates existing offsets in the percpu area and it
   invokes the inner tunnel parser again.

8) Add support for inner meta matching. This support for
   NFTA_META_PROTOCOL, which specifies the inner ethertype, and
   NFT_META_L4PROTO, which specifies the inner transport protocol.

9) Extend nft_inner to parse GENEVE optional fields to calculate the
   link layer offset.

10) Update inner expression so tunnel offset points to GRE header
    to normalize tunnel header handling. This also allows to perform
    different interpretations of the GRE header from userspace.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nft_inner: set tunnel offset to GRE header offset
  netfilter: nft_inner: add geneve support
  netfilter: nft_meta: add inner match support
  netfilter: nft_inner: add percpu inner context
  netfilter: nft_inner: support for inner tunnel header matching
  netfilter: nft_payload: access ipip payload for inner offset
  netfilter: nft_payload: access GRE payload via inner offset
  netfilter: nft_objref: make it builtin
  netfilter: nf_tables: reduce nft_pktinfo by 8 bytes
  netfilter: nft_payload: move struct nft_payload_set definition where it belongs
====================

Link: https://lore.kernel.org/r/20221026132227.3287-1-pablo@netfilter.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

./drivers/net/ethernet/freescale/dpaa2/dpaa2-xsk.c:453:42-47: WARNING: conversion to bool not needed here

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=2577Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20221026051824.38730-1-yang.lee@linux.alibaba.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Shannon Nelson says:

====================
ionic: VF attr replay and other updates

For better VF management when a FW update restart or a FW crash recover is
detected, the PF now will replay any user specified VF attributes to be
sure the FW hasn't lost them in the restart.

Newer FW offers more packet processing offloads, so we now support them in
the driver.

A small refactor of the Rx buffer fill cleans a bit of code and will help
future work on buffer caching.
====================

Link: https://lore.kernel.org/r/20221026143744.11598-1-snelson@pensando.ioSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The same pre-work code is used before each call to
ionic_rx_fill(), so bring it in and make it a part of
the routine.
Signed-off-by: Neel Patel <neel@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Support stateless offloads for GRE, VXLAN, GENEVE, IPXIP4
and IPXIP6 when the FW supports them.
Signed-off-by: Neel Patel <neel@pensando.io>
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

A new ionic dev_cmd is added to the interface in ionic_if.h,
with a new capabilities field in the ionic device identity to
signal its availability in the FW.  The identity level code is
incremented to '2' to show support for this new capabilities
bitfield.

If the driver has indicated with the new identity level that
it has the VF_CTRL command, newer FW will wait for the start
command before starting the VFs after a FW update or crash
recovery.

This patch updates the driver to make use of the new VF start
control in fw_up path to be sure that the PF has set the user
attributes on the VF before the FW allows the VFs to restart.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Report the current FW values for the VF attributes, but don't
save the FW values locally, only save the vf attributes that
are given to us from the user.  This allows us to replay user
data, and doesn't end up confusing things like "who set the
mac address".
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The VF attributes that the user has set into the FW through
the PF can be lost over a FW crash recovery.  Much like we
already replay the PF mac/vlan filters, we now add a replay
in the recovery path to be sure the FW has the up-to-date
VF configurations.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
  2871edb3 ("can: kvaser_usb: Fix possible completions during init_completion")
  abb86709 ("can: kvaser_usb_leaf: Ignore stale bus-off after start")
  8d21f592 ("can: kvaser_usb_leaf: Fix improved state not being reported")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull networking fixes from Jakub Kicinski:
 "Including fixes from 802.15.4 (Zigbee et al).

  Current release - regressions:

   - ipa: fix bugs in the register conversion for IPA v3.1 and v3.5.1

  Current release - new code bugs:

   - mptcp: fix abba deadlock on fastopen

   - eth: stmmac: rk3588: allow multiple gmac controllers in one system

  Previous releases - regressions:

   - ip: rework the fix for dflt addr selection for connected nexthop

   - net: couple more fixes for misinterpreting bits in struct page
     after the signature was added

  Previous releases - always broken:

   - ipv6: ensure sane device mtu in tunnels

   - openvswitch: switch from WARN to pr_warn on a user-triggerable path

   - ethtool: eeprom: fix null-deref on genl_info in dump

   - ieee802154: more return code fixes for corner cases in
     dgram_sendmsg

   - mac802154: fix link-quality-indicator recording

   - eth: mlx5: fixes for IPsec, PTP timestamps, OvS and conntrack
     offload

   - eth: fec: limit register access on i.MX6UL

   - eth: bcm4908_enet: update TX stats after actual transmission

   - can: rcar_canfd: improve IRQ handling for RZ/G2L

  Misc:

   - genetlink: piggy back on the newly added resv_op_start to enforce
     more sanity checks on new commands"

* tag 'net-6.1-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (57 commits)
  net: enetc: survive memory pressure without crashing
  kcm: do not sense pfmemalloc status in kcm_sendpage()
  net: do not sense pfmemalloc status in skb_append_pagefrags()
  net/mlx5e: Fix macsec sci endianness at rx sa update
  net/mlx5e: Fix wrong bitwise comparison usage in macsec_fs_rx_add_rule function
  net/mlx5e: Fix macsec rx security association (SA) update/delete
  net/mlx5e: Fix macsec coverity issue at rx sa update
  net/mlx5: Fix crash during sync firmware reset
  net/mlx5: Update fw fatal reporter state on PCI handlers successful recover
  net/mlx5e: TC, Fix cloned flow attr instance dests are not zeroed
  net/mlx5e: TC, Reject forwarding from internal port to internal port
  net/mlx5: Fix possible use-after-free in async command interface
  net/mlx5: ASO, Create the ASO SQ with the correct timestamp format
  net/mlx5e: Update restore chain id for slow path packets
  net/mlx5e: Extend SKB room check to include PTP-SQ
  net/mlx5: DR, Fix matcher disconnect error flow
  net/mlx5: Wait for firmware to enable CRS before pci_restore_state
  net/mlx5e: Do not increment ESN when updating IPsec ESN state
  netdevsim: remove dir in nsim_dev_debugfs_init() when creating ports dir failed
  netdevsim: fix memory leak in nsim_drv_probe() when nsim_dev_resources_register() failed
  ...

Pull execve fixes from Kees Cook:

 - Fix an ancient signal action copy race (Bernd Edlinger)

 - Fix a memory leak in ELF loader, when under memory pressure (Li
   Zetao)

* tag 'execve-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  fs/binfmt_elf: Fix memory leak in load_elf_binary()
  exec: Copy oldsighand->action under spin-lock

Pull hardening fixes from Kees Cook:

 - Fix older Clang vs recent overflow KUnit test additions (Nick
   Desaulniers, Kees Cook)

 - Fix kern-doc visibility for overflow helpers (Kees Cook)

* tag 'hardening-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  overflow: Refactor test skips for Clang-specific issues
  overflow: disable failing tests for older clang versions
  overflow: Fix kern-doc markup for functions

Pull media fixes from Mauro Carvalho Chehab:
 "A bunch of patches addressing issues in the vivid driver and adding
  new checks in V4L2 to validate the input parameters from some ioctls"

* tag 'media/v6.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: vivid.rst: loop_video is set on the capture devnode
  media: vivid: set num_in/outputs to 0 if not supported
  media: vivid: drop GFP_DMA32
  media: vivid: fix control handler mutex deadlock
  media: videodev2.h: V4L2_DV_BT_BLANKING_HEIGHT should check 'interlaced'
  media: v4l2-dv-timings: add sanity checks for blanking values
  media: vivid: dev->bitmap_cap wasn't freed in all cases
  media: vivid: s_fbuf: add more sanity checks

Pull fscrypt fix from Eric Biggers:
 "Fix a memory leak that was introduced by a change that went into -rc1"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  fscrypt: fix keyring memory leak on mount failure

Under memory pressure, enetc_refill_rx_ring() may fail, and when called
during the enetc_open() -> enetc_setup_rxbdr() procedure, this is not
checked for.

An extreme case of memory pressure will result in exactly zero buffers
being allocated for the RX ring, and in such a case it is expected that
hardware drops all RX packets due to lack of buffers.

This does not happen, because the reset-default value of the consumer
and produces index is 0, and this makes the ENETC think that all buffers
have been initialized and that it owns them (when in reality none were).

The hardware guide explains this best:

| Configure the receive ring producer index register RBaPIR with a value
| of 0. The producer index is initially configured by software but owned
| by hardware after the ring has been enabled. Hardware increments the
| index when a frame is received which may consume one or more BDs.
| Hardware is not allowed to increment the producer index to match the
| consumer index since it is used to indicate an empty condition. The ring
| can hold at most RBLENR[LENGTH]-1 received BDs.
|
| Configure the receive ring consumer index register RBaCIR. The
| consumer index is owned by software and updated during operation of the
| of the BD ring by software, to indicate that any receive data occupied
| in the BD has been processed and it has been prepared for new data.
| - If consumer index and producer index are initialized to the same
|   value, it indicates that all BDs in the ring have been prepared and
|   hardware owns all of the entries.
| - If consumer index is initialized to producer index plus N, it would
|   indicate N BDs have been prepared. Note that hardware cannot start if
|   only a single buffer is prepared due to the restrictions described in
|   (2).
| - Software may write consumer index to match producer index anytime
|   while the ring is operational to indicate all received BDs prior have
|   been processed and new BDs prepared for hardware.

Normally, the value of rx_ring->rcir (consumer index) is brought in sync
with the rx_ring->next_to_use software index, but this only happens if
page allocation ever succeeded.

When PI==CI==0, the hardware appears to receive frames and write them to
DMA address 0x0 (?!), then set the READY bit in the BD.

The enetc_clean_rx_ring() function (and its XDP derivative) is naturally
not prepared to handle such a condition. It will attempt to process
those frames using the rx_swbd structure associated with index i of the
RX ring, but that structure is not fully initialized (enetc_new_page()
does all of that). So what happens next is undefined behavior.

To operate using no buffer, we must initialize the CI to PI + 1, which
will block the hardware from advancing the CI any further, and drop
everything.

The issue was seen while adding support for zero-copy AF_XDP sockets,
where buffer memory comes from user space, which can even decide to
supply no buffers at all (example: "xdpsock --txonly"). However, the bug
is present also with the network stack code, even though it would take a
very determined person to trigger a page allocation failure at the
perfect time (a series of ifup/ifdown under memory pressure should
eventually reproduce it given enough retries).

Fixes: d4fd0404 ("enetc: Introduce basic PF and VF ENETC ethernet drivers")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Link: https://lore.kernel.org/r/20221027182925.3256653-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Similar to changes done in TCP in blamed commit.
We should not sense pfmemalloc status in sendpage() methods.

Fixes: 32614006 ("tcp: TX zerocopy should not sense pfmemalloc status")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221027040637.1107703-1-edumazet@google.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>