AppleTalk keeps its per-interface control block (struct atalk_iface)
directly in struct netdevice (dev->atalk_ptr). This is the only thing
tying the protocol into the core net_device layout and is the sole
blocker to moving AppleTalk out of tree.
Replace dev->atalk_ptr with a small ifindex-keyed hashtable internal
to ddp.c. The existing atalk_interfaces list stays the owner of the iface
objects; the hashtable is purely a fast dev->iface index and reuses
the same atalk_interfaces_lock.
AFAICT this patch does not make this code any more racy than it already
is, I'm sure Sashiko will point out some basically existing bugs.
AFAICT atalk_interfaces_lock is the innermost lock already.
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://patch.msgid.link/20260615222935.947233-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently sk_rethink_txhash() re-rolls the socket's txhash on RTO, PLB,
and spurious-retransmission events, but the cached route is reused and
the new hash is not propagated into the ECMP path selection logic. Two
changes are needed to make rehash select a different local ECMP path:
1. Add __sk_dst_reset() alongside sk_rethink_txhash() in
tcp_write_timeout(), tcp_rcv_spurious_retrans(), and
tcp_plb_check_rehash() so the cached dst is invalidated and the
next transmit triggers a fresh route lookup.
2. Set fl6->mp_hash from sk_txhash (or tcp_rsk(req)->txhash for
SYN/ACK retransmits and syncookies) in tcp_v6_connect(),
inet6_sk_rebuild_header(), inet6_csk_route_req(),
inet6_csk_route_socket(), tcp_v6_send_response(), and
cookie_v6_check() so fib6_select_path() picks a path based on the
new hash.
The mp_hash override only applies to fib_multipath_hash_policy 0 (the
default L3 policy). Its hash includes the flow label, but that is 0 by
default -- np->flow_label is unset, and auto_flowlabels only computes
the on-wire label later, per packet -- so flows to the same peer share
one local path. Keying the hash on sk_txhash makes the local path
per-connection and lets a rehash re-select it. Policies 1-3 are left
unchanged.
The mp_hash assignment is factored into a small helper,
ip6_ecmp_set_mp_hash(), shared by inet6_csk_route_req(),
inet6_csk_route_socket(), tcp_v6_connect(), inet6_sk_rebuild_header(),
tcp_v6_send_response(), and cookie_v6_check(). It applies
(txhash >> 1) ?: 1 for policy 0 (the >> 1 keeps mp_hash in the 31-bit
range; ?: 1 keeps it non-zero, since 0 would fall back to
rt6_multipath_hash()). inet6_csk_route_socket() calls it only for
sk_protocol == IPPROTO_TCP so that non-TCP callers (e.g., L2TP via
inet6_csk_xmit) fall through to rt6_multipath_hash() and retain their
existing flow-key-based ECMP behavior.
tcp_v6_send_response() also sets mp_hash from the response txhash so
that a control packet (a RST from the full socket, or an ACK from a
time-wait socket) selects the same local ECMP nexthop as the
connection's txhash rather than falling back to the flow hash. The
time-wait socket's tw_txhash is copied from sk_txhash when the
connection enters TIME_WAIT, so it reflects any rehash that occurred.
Setting mp_hash explicitly is necessary because the default ECMP hash
derives from fl6->flowlabel via np->flow_label, which is not updated
from sk_txhash (REPFLOW is off by default). ip6_make_flowlabel()
cannot help either, as it runs after the route lookup.
As a consequence, for policy 0 the local ECMP path of an IPv6 TCP
flow follows sk_txhash even when fl6->flowlabel is non-zero, e.g. a
reflected (REPFLOW) or explicitly set (IPV6_FLOWLABEL_MGR) flow
label. This is intentional: only local path selection changes, so
rehash can recover from a failed path; the on-wire flow label is
unchanged.
sk_set_txhash() is moved before ip6_dst_lookup_flow() in
tcp_v6_connect() so the initial ECMP path is selected by the same
txhash that subsequent route rebuilds will use. This avoids
unintended path changes when the cached dst is naturally invalidated
(e.g., by PMTU discovery or route changes).
The rehash sites (tcp_write_timeout(), tcp_plb_check_rehash(), and
tcp_rcv_spurious_retrans()) call __sk_rethink_txhash_reset_dst(),
which re-rolls the txhash and, when it changed, drops the cached dst
so the next transmit re-runs route selection. The dst reset is
guarded by sk->sk_family == AF_INET6 since IPv4 ECMP does not
currently use sk_txhash for path selection. For IPv4-mapped IPv6
sockets this produces a redundant dst reset on a cold path
(RTO/PLB); the subsequent IPv4 route lookup returns the same result.
The helper is deliberately separate from sk_rethink_txhash() itself:
dst_negative_advice() calls sk_rethink_txhash() before its own dst op,
so resetting the dst inside sk_rethink_txhash() would skip that op
(e.g. rt6_remove_exception_rt()).
For syncookies, cookie_init_sequence() computes the cookie value
before route_req() and sets txhash so the SYN-ACK selects the same
ECMP path that cookie_v6_check() will use when the full socket is
created. cookie_tcp_reqsk_init() derives txhash from the cookie so
the full socket's ECMP path matches the SYN-ACK. Both the SYN-ACK
assignment in tcp_conn_request() and the full-socket assignment in
cookie_tcp_reqsk_init() set txhash from the cookie for IPv4 and IPv6
alike. On IPv6 this drives ECMP path selection; on IPv4, which does
not use sk_txhash for ECMP, it only affects TX-queue selection. That
selection scales the hash by its high bits (reciprocal_scale()), which
are uniform in the keyed secure_tcp_syn_cookie() output -- the MSS index
only perturbs the low bits -- so the queue distribution matches
net_tx_rndhash().
cookie_init_sequence() is split from the former version that also
called tcp_synq_overflow() and incremented SYNCOOKIESSENT; those
side effects are now in cookie_record_sent(), called after
route_req() succeeds so they are not bumped when route_req() fails.
cookie_record_sent() is guarded by CONFIG_SYN_COOKIES to
match the guard on tcp_synq_overflow(). route_req() receives 0 as
tw_isn for the syncookie path so that tcp_v6_init_req() still saves
ireq->pktopts for REPFLOW flowlabel reflection and IPv6 cmsg
options. The ecn_ok clear for syncookies without timestamps stays
after tcp_ecn_create_request() so it takes precedence.
Signed-off-by: Neil Spring <ntspring@meta.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260615042158.1600746-2-ntspring@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Not sure if anyone would read this doc, but the API has evolved
since it was written. Update to:
- show the int return type for strp_init()
- refer to strp_data_ready(), not the old strp_tcp_data_ready() name
- direct users to strp_msg(skb) for strparser metadata instead of
treating skb->cb as struct strp_msg directly
Link: https://patch.msgid.link/20260613165846.2913092-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update devlink documentation to match current code:
- describe health reporter defaults (it's currently under "callbacks"),
best-effort auto-dump, and port-scoped reporters
- fix generic parameter names and values
- fix nested devlink setup wording and registration ordering
Link: https://patch.msgid.link/20260613165846.2913092-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for net-next.
More specifically, this contains conncount rework to address AI related
reports, assorted Netfiter updates and two small incremental updates on
IPVS:
1) Replace old obsolete workqueues (system_wq, system_unbound_wq)
in IPVS, from Marco Crivellari.
2) Replace WARN_ON{_ONCE} by DEBUG_NET_WARN_ON_ONCE in nf_tables.
In the recent years, reporters say that the use of WARN_ON{_ONCE}
in conjunction with panic_on_warn=1 results in DoS. Let's replace
it by DEBUG_NET_WARN_ON_ONCE so this is only exercised by test
infrastructure and fuzzers, while also providing context to AI
agents. From Fernando F. Mancera.
Five patches from Florian Westphal to address AI reports in the conncount
infrastructures:
3) Fix missing rcu read lock section when calling
__ovs_ct_limit_get_zone_limit().
4) Add a dedicate lock per rbtree tree, this increases memory
usage but it should improve scalability.
5) Add a helper function to find the rbtree node, no functional
changes are intented.
6) Add sequence counter to detect concurrent tree modifications
and retry lookups.
7) Add locks to GC conncount walk and address other nitpicks.
Then, several assorted updates:
8) Defensive Tree-wide addition of NULL checks for ct extensions.
9) Bail out if flowtable bypass cannot be fully set up from the
flow offload expression, instead of lazy building a likely
incomplete one.
10) Fix documentation for the new conn_max sysctl toggle in IPVS.
11) Add nf_dev_xmit_recursion*() helpers and use them, to address
recent AI reports.
* tag 'nf-next-26-06-14' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_dup_netdev: add nf_dev_xmit_recursion*() helpers and use them
ipvs: fix doc syntax for conn_max sysctl
netfilter: flowtable: bail out if forward path cannot be discovered
netfilter: conntrack: check NULL when retrieving ct extension
netfilter: nf_conncount: gc and rcu fixes
netfilter: nf_conncount: add sequence counter to detect tree modifications
netfilter: nf_conncount: split count_tree_node rbtree walk into helper
netfilter: nf_conncount: use per nf_conncount_data spinlocks
netfilter: nf_conncount: callers must hold rcu read lock
netfilter: nf_tables: use DEBUG_NET_WARN_ON_ONCE in packet and control paths
ipvs: Replace use of system_unbound_wq with system_dfl_long_wq
====================
Link: https://patch.msgid.link/20260614114605.474783-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Fix the docutils error reported by kernel test robot
for the new conn_max sysctl:
Documentation/networking/ipvs-sysctl.rst:76: WARNING: Block quote ends
without a blank line; unexpected unindent. [docutils]
Documentation/networking/ipvs-sysctl.rst:76: ERROR: Unexpected section
title or transition.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202606071851.Dc1H7hOO-lkp@intel.com/
Fixes: 4a15044a2b ("ipvs: add conn_max sysctl to limit connections")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Convert lan9303.txt to yaml format to fix below CHECK_DTBS warnings:
arch/arm/boot/dts/nxp/imx/imx53-kp-hsc.dtb: /soc/bus@50000000/i2c@53fec000/switch@a: failed to match any schema with compatible: ['smsc,lan9303-i2c']
Additional changes:
- rename switch-phy to switch in example.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260610150533.515914-1-Frank.Li@oss.nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Steffen Klassert says:
====================
pull request (net-next): ipsec-next 2026-06-12
1) Replace the open-coded manual cleanup in xfrm_add_policy() error
path with xfrm_policy_destroy() for consistency with
xfrm_policy_construct().
From Deepanshu Kartikey.
2) Limit XFRMA_TFCPAD to a sensible maximum (max IP length, 64k) since
u32 is excessive for traffic flow confidentiality padding.
From David Ahern.
3) Add a new netlink message XFRM_MSG_MIGRATE_STATE that
allows migrating individual IPsec SAs independently of
their policies. The existing XFRM_MSG_MIGRATE is tightly coupled
to policy+SA migration, lacks SPI for unique SA identification,
and cannot express reqid changes or migrate Transport mode
selectors. The new interface identifies the SA via SPI and mark,
supports reqid changes, address family changes, encap removal,
and uses an atomic create+install flow under x->lock to prevent
SN/IV reuse during AEAD SA migration.
From Antony Antony.
* tag 'ipsec-next-2026-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next:
xfrm: add documentation for XFRM_MSG_MIGRATE_STATE
xfrm: restrict netlink attributes for XFRM_MSG_MIGRATE_STATE
xfrm: add XFRM_MSG_MIGRATE_STATE for single SA migration
xfrm: make xfrm_dev_state_add xuo parameter const
xfrm: extract address family and selector validation helpers
xfrm: refactor XFRMA_MTIMER_THRESH validation into a helper
xfrm: move encap and xuo into struct xfrm_migrate
xfrm: add error messages to state migration
xfrm: add state synchronization after migration
xfrm: check family before comparing addresses in migrate
xfrm: split xfrm_state_migrate into create and install functions
xfrm: rename reqid in xfrm_migrate
xfrm: fix NAT-related field inheritance in SA migration
xfrm: allow migration from UDP encapsulated to non-encapsulated ESP
xfrm: add extack to xfrm_init_state
xfrm: remove redundant assignments
xfrm: Reject excessive values for XFRMA_TFCPAD
xfrm: cleanup error path in xfrm_add_policy()
====================
Link: https://patch.msgid.link/20260612074725.1760473-1-steffen.klassert@secunet.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Every now and then someone tries to duplicated extack
messages to dmesg. Document our guidance against this.
Also indicate that system level faults should continue
to go to system logs. The high level thinking is to try
to distinguish between what's important to the user vs
system admin.
Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20260611172149.1877704-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Minor updates to the XDP metadata documentation:
- s/union/struct/ for xsk_tx_metadata
- document nested request and completion metadata fields
- point capability queries at the xsk-features attribute
- fix grammar in the XDP RX metadata guide
- typos
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://patch.msgid.link/20260609201224.1191391-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This sysctl is going to be used in the next commits to drop TCP
timestamps option, to be able to send an ADD_ADDR with a v6 IP address
and a port number. It is enabled by default.
This knob is explicitly disabled in the MPTCP Join selftest, with the
"signal addr list progresses after tx drop" subtest, to continue
verifying the previous behaviour where the ADD_ADDR is not sent due to a
lack of space.
While at it, move syn_retrans_before_tcp_fallback down from struct
mptcp_pernet, to avoid creating another 3 bytes hole.
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260605-net-next-mptcp-add-addr6-port-ts-v2-4-758e7ca73f4d@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an 802.3ad (LACP) bonding interface has no slaves in the
collecting/distributing state, the bonding master still reports
carrier as up as long as at least 'min_links' slaves have carrier.
In this situation, only one slave is effectively used for TX/RX,
while traffic received on other slaves is dropped. Upper-layer
daemons therefore consider the interface operational, even though
traffic may be blackholed if the lack of LACP negotiation means
the partner is not ready to deal with traffic.
Introduce a configuration knob to control this behavior. It allows
the bonding master to assert carrier only when at least 'min_links'
slaves are in Collecting_Distributing state.
The default mode preserves the existing behavior. This patch only
introduces the knob; its behavior is implemented in the subsequent
commit.
Fixes: 655f8919d5 ("bonding: add min links parameter to 802.3ad")
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>
Acked-by: Jay Vosburgh <jv@jvosburgh.net>
Link: https://patch.msgid.link/20260603150331.1919611-4-louis.scalbert@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dsa.txt has been a redirect to dsa.yaml since commit bce58590d1
("dt-bindings: net: dsa: Add DSA yaml binding") introduced the .yaml
schema. The .yaml has the same filename in the same directory, making
this redirect unnecessary for discoverability.
Two files still reference dsa.txt, forcing readers through an extra
hop to reach the .yaml. The stub has not been touched since August
2020. Update references in lan9303.txt and
Documentation/networking/dsa/dsa.rst to point directly to dsa.yaml
and remove the stub.
Signed-off-by: Akash Sukhavasi <akash.sukhavasi@gmail.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260603-b4-remove-redirect-stubs-v2-3-c8c19876ab64@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add documentation for the new XFRM_MSG_MIGRATE_STATE netlink message,
which migrates a single SA identified by SPI and mark without involving
policies.
The document covers the motivation and design differences from the
existing XFRM_MSG_MIGRATE, the SA lookup mechanism, supported attributes
with their omit-to-inherit semantics, and usage examples.
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
The Netlink support for querying page pool stats has been
proven out in production, let's remove the mention of the
helper meant for dumping page pool stats into ethtool -S
from the docs.
Call out in the kdoc that this API is deprecated.
Some drivers may not be able to use the Netlink API
(if page pool is shared across netdevs). So the old API
is not _completely_ dead. But we shouldn't advertise it.
Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260526155722.2790742-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update the segmentation offload documentation to match current GSO types:
- clarify csum_start for encapsulated TSO
- document TCP AccECN GSO and NETIF_F_GSO_ACCECN
- distinguish legacy UFO from UDP L4 GSO
- add ESP and fraglist GSO entries
Link: https://patch.msgid.link/20260526160151.2793354-11-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The Rx checksum processing gives people pause. The two main questions
in my experience are:
- what to do with bad IPv4 checksum; and
- what to do with packets with bad checksum.
Folks often feel the urge to drop the latter, to "avoid overloading
the host".
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260526160151.2793354-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update the checksum offload documentation to match current code:
- SCTP CRC32c offload requires NETIF_F_SCTP_CRC, not ordinary IP
checksum offload
- NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are restricted legacy
features; new devices should use NETIF_F_HW_CSUM
- GRE LCO is handled by the shared gre_build_header() helper used by
both IPv4 and IPv6 GRE
- VXLAN_F_REMCSUM_TX is a VXLAN configuration flag, not a field of
struct vxlan_rdst
Link: https://patch.msgid.link/20260526160151.2793354-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update netdev feature documentation for current locking rules and
feature semantics. Clarify hw_features updates and netdev_update_features()
locking, keep the NETIF_F_NEVER_CHANGE rule with the VLAN challenged
exception, fix the HSR duplication wording, and document netdev->netmem_tx
as a device flag rather than a feature bit.
Split the list of basic feature sets from the "extra" ones like
vlan_features. A bunch of the newer fields weren't documented and
having them all together would be confusing.
Link: https://patch.msgid.link/20260526160151.2793354-7-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update the NAPI documentation to match current API behavior:
- repeated napi_disable() calls hang waiting for ownership, rather
than deadlock
- NAPI IDs are exposed through SO_INCOMING_NAPI_ID and netdev Netlink
- epoll uses the maxevents parameter spelling
- add that drivers holding the netdev instance lock may need _locked()
variants
Link: https://patch.msgid.link/20260526160151.2793354-6-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update the kernel-internal ethtool stats list to match current code:
- spell the entries as "struct ethtool_*_stats", not as functions
- list the full set of structures, not only pause and fec
- mention that fields are pre-initialized to ETHTOOL_STAT_NOT_SET by
ethtool_stats_init() and drivers should leave unsupported fields at
that value rather than zeroing them
Link: https://patch.msgid.link/20260526160151.2793354-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update the driver documentation TX queue example to match current APIs:
- use the ring-local tx_ring_mask field in drv_tx_avail()
- stop the selected netdev_queue with netif_tx_stop_queue() instead of
stopping queue 0 with netif_stop_queue()
Link: https://patch.msgid.link/20260526160151.2793354-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
A handful of unrelated nits:
- free_netdevice() does not exist; replace two stray references
with free_netdev().
- The simple-driver probe example fell through into err_undo after
register_netdev() success; add return 0 for clarity.
- Clarify the netdev_priv() paragraph: "(netdev_priv())" was easy
to misread as the thing that needs explicit freeing; spell out
that it refers to extra pointers stored in the device private
struct.
- ndo_setup_tc synchronization note: TC_SETUP_BLOCK / TC_SETUP_FT
actually run under block->cb_lock, not "NFT locks", and rtnl_lock
may or may not be held depending on path.
- ->lltx guidance reads as very outdated, it's not really deprecated.
I suspect people may have been trying to use it for HW drivers
in the past but I can't think of such a case in the last decade.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20260526160151.2793354-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The ARCnet documentation contains a lot of outdated and irrelevant
information (such as changes in decades-old driver versions and
messages from a former maintainer) and has some writing style issues.
Remove this unnecessary information and improve the writing style. Also
remove links to pages that no longer exist.
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Link: https://patch.msgid.link/20260521001631.45434-7-enelsonmoore@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
While ARCnet is still used in industrial environments, and cards are
still manufactured, it is unlikely anyone is still using it with ISA
and PCMCIA cards. Reduce future maintenance burden by removing all ISA
and PCMCIA ARCnet drivers and documentation related to them. Update
instructions for loading modules and passing parameters to work on
modern kernels and with the com20020_pci driver. Also take the
opportunity to document the rest of the module parameters, correct a
file path in Documentation/networking/arcnet.rst, and change a
reference to /etc/rc.inet1, which no longer exists, to refer to
ifconfig.
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Link: https://patch.msgid.link/20260521001631.45434-4-enelsonmoore@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There has been apparently a single message only ever publicly posted by
David Ruggiero, back in 2002, which added this documentation piece among
others, and MAINTAINERS was never updated accordingly. It is therefore
doubtful that his maintainer status has actually come into effect. Just
replace the reference then so as not to confuse people.
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Link: https://patch.msgid.link/alpine.DEB.2.21.2605201207380.1450@angie.orcam.me.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some virtual devices like netkit (or ifb) never DMA and never touch frag
contents, they just forward the skb to another device. They are unable
to forward unreadable skbs, however, because they fail to pass TX
validation checks on dev->netmem_tx. The existing two-state
NETMEM_TX_NONE / NETMEM_TX_DMA doesn't give the TX validator enough
information to differentiate devices that will attempt DMA on the
unreadable skb from those that will simply route it untouched.
Add a third mode to the enum so drivers can indicate 1) if they have
netmem TX support, and 2) if they do, whether they are DMA-capable:
NETMEM_TX_NO_DMA - pass-through, device never DMAs
Widen dev->netmem_tx from a 1-bit field to 2 bits to fit the new value,
and declare netkit as NETMEM_TX_NO_DMA. Devmem TX support over these
devices comes in a follow-up patch.
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260514-tcp-dm-netkit-v5-2-408c59b91e66@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Devices that support netmem TX previously set dev->netmem_tx = true.
This was checked in validate_xmit_unreadable_skb() to drop unreadable
skbs (skbs with dmabuf-backed frags) before they reach drivers that
would mishandle them or devices that would not have the iommu mappings
for them.
A subsequent patch will introduce a third state for virtual devices
that forward unreadable skbs without ever performing DMA on them. To
prepare for that, convert the boolean dev->netmem_tx into an enum:
NETMEM_TX_NONE - no netmem TX support (drop unreadable skbs)
NETMEM_TX_DMA - full support, device does DMA
Update the existing NIC drivers (bnxt, gve, mlx5, fbnic) and the
validators in net/core to use the new enum. No functional change.
Acked-by: Harshitha Ramamurthy <hramamurthy@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
Link: https://patch.msgid.link/20260514-tcp-dm-netkit-v5-1-408c59b91e66@meta.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The cs89x0 driver is really two in one, and they are mutually exclusive:
- the ISA driver was used on 486-era PCs. It likely has no remaining
users, like the other ethernet drivers that got removed in
linux-7.1. The DMA support in here is the last device driver use of
the deprecated isa_bus_to_virt() interface, all other users are either
x86 specific or or got converted to the normal dma-mapping interface.
The driver was maintained by Andrew Morton at the time, based on
the linux-2.2 vendor driver from Cirrus Logic.
- the platform_driver instance was used on some embedded Arm boards
around the same time, such as the EP7211 Development Kit. This
is the same chip, but uses modern devicetree based probing and no DMA.
This was added by Alexander Shiyan.
Remove the ISA driver as a cleanup, including all of the outdated
documentation referring to its configuration.
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260429145624.2948432-1-arnd@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The smc-sysctl.rst documentation incorrectly stated that
the previous hardcoded maximum number of WR buffers on
the receive path (smcr_max_recv_wr) was 16.
The correct historical value used before the introduction of
the sysctl control was 48. Update the documentation to reflect
the accurate historical value. Also fix a couple of minor typos.
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com>
Signed-off-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Link: https://patch.msgid.link/20260424052336.3262350-1-mjambigi@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull networking deletions from Jakub Kicinski:
"Delete some obsolete networking code
Old code like amateur radio and NFC have long been a burden to core
networking developers. syzbot loves to find bugs in BKL-era code, and
noobs try to fix them.
If we want to have a fighting chance of surviving the LLM-pocalypse
this code needs to find a dedicated owner or get deleted. We've talked
about these deletions multiple times in the past and every time
someone wanted the code to stay. It is never very clear to me how many
of those people actually use the code vs are just nostalgic to see it
go. Amateur radio did have occasional users (or so I think) but most
users switched to user space implementations since its all super slow
stuff. Nobody stepped up to maintain the kernel code.
We were lucky enough to find someone who wants to help with NFC so
we're giving that a chance. Let's try to put the rest of this code
behind us"
* tag 'net-deletions' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next:
drivers: net: 8390: wd80x3: Remove this driver
drivers: net: 8390: ultra: Remove this driver
drivers: net: 8390: AX88190: Remove this driver
drivers: net: fujitsu: fmvj18x: Remove this driver
drivers: net: smsc: smc91c92: Remove this driver
drivers: net: smsc: smc9194: Remove this driver
drivers: net: amd: nmclan: Remove this driver
drivers: net: amd: lance: Remove this driver
drivers: net: 3com: 3c589: Remove this driver
drivers: net: 3com: 3c574: Remove this driver
drivers: net: 3com: 3c515: Remove this driver
drivers: net: 3com: 3c509: Remove this driver
net: packetengines: remove obsolete yellowfin driver and vendor dir
net: packetengines: remove obsolete hamachi driver
net: remove unused ATM protocols and legacy ATM device drivers
net: remove ax25 and amateur radio (hamradio) subsystem
net: remove ISDN subsystem and Bluetooth CMTP
caif: remove CAIF NETWORK LAYER
