When the IPA driver has completed its initialization and setup
stages, it emits a brief message to the log.  Add a small message
that reports when it has been removed.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

In gsi_trans_free(), there's no point in ipa_gsi_trans_release() if
a transaction is unused.  No used TREs means no IPA layer resources
to clean up.  So only call ipa_gsi_trans_release() if at least one
TRE was used.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

The transaction map is really associated with the transaction pool;
move its definition earlier in the gsi_trans_info structure.

Rearrange initialization in gsi_channel_trans_init() so it
sets the tre_avail value first, then initializes the transaction
pool, and finally allocating the transaction map.

Update comments.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We currently put a transaction on the pending list when it has
been committed.  But until the channel's doorbell rings, these
transactions aren't actually "owned" by the hardware yet.

Add a new "committed" state (and list), to represent transactions
that have been committed but not yet sent to hardware.  Define
"pending" to mean committed transactions that have been sent
to hardware but have not yet completed.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Create a new attribute group meant to provide a single place that
defines endpoint IDs that might be needed by user space.  Not all
defined endpoints are presented, and only those that are defined
will be made visible.

The new attributes use "extended" device attributes to hold endpoint
IDs, which is a little more compact and efficient.  Reimplement the
existing modem endpoint ID attribute files using common code.
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220719191639.373249-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

This patch fixes a build error reported in the link. [0]

  unix_connect.c: In function ‘unix_connect_test’:
  unix_connect.c:115:55: error: expected identifier before ‘(’ token
   #define offsetof(type, member) ((size_t)&((type *)0)->(member))
                                                       ^
  unix_connect.c:128:12: note: in expansion of macro ‘offsetof’
    addrlen = offsetof(struct sockaddr_un, sun_path) + variant->len;
              ^~~~~~~~

We can fix this by removing () around member, but checkpatch will complain
about it, and the root cause of the build failure is that I followed the
warning and fixed this in the v2 -> v3 change of the blamed commit. [1]

  CHECK: Macro argument 'member' may be better as '(member)' to avoid precedence issues
  #33: FILE: tools/testing/selftests/net/af_unix/unix_connect.c:115:
  +#define offsetof(type, member) ((size_t)&((type *)0)->member)

To avoid this warning, let's use offsetof() defined in stddef.h instead.

[0]: https://lore.kernel.org/linux-mm/202207182205.FrkMeDZT-lkp@intel.com/
[1]: https://lore.kernel.org/netdev/20220702154818.66761-1-kuniyu@amazon.com/

Fixes: e95ab1d8 ("selftests: net: af_unix: Test connect() with different netns.")
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20220720005750.16600-1-kuniyu@amazon.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

It's repeated with line 1793-1795, and there isn't any other
handling for it. So remove it.
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Link: https://lore.kernel.org/r/20220719142424.4528-1-shenjian15@huawei.comSigned-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:

1) Simplify nf_ct_get_tuple(), from Jackie Liu.

2) Add format to request_module() call, from Bill Wendling.

3) Add /proc/net/stats/nf_flowtable to monitor in-flight pending
   hardware offload objects to be processed, from Vlad Buslov.

4) Missing rcu annotation and accessors in the netfilter tree,
   from Florian Westphal.

5) Merge h323 conntrack helper nat hooks into single object,
   also from Florian.

6) A batch of update to fix sparse warnings treewide,
   from Florian Westphal.

7) Move nft_cmp_fast_mask() where it used, from Florian.

8) Missing const in nf_nat_initialized(), from James Yonan.

9) Use bitmap API for Maglev IPVS scheduler, from Christophe Jaillet.

10) Use refcount_inc instead of _inc_not_zero in flowtable,
    from Florian Westphal.

11) Remove pr_debug in xt_TPROXY, from Nathan Cancellor.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: xt_TPROXY: remove pr_debug invocations
  netfilter: flowtable: prefer refcount_inc
  netfilter: ipvs: Use the bitmap API to allocate bitmaps
  netfilter: nf_nat: in nf_nat_initialized(), use const struct nf_conn *
  netfilter: nf_tables: move nft_cmp_fast_mask to where its used
  netfilter: nf_tables: use correct integer types
  netfilter: nf_tables: add and use BE register load-store helpers
  netfilter: nf_tables: use the correct get/put helpers
  netfilter: x_tables: use correct integer types
  netfilter: nfnetlink: add missing __be16 cast
  netfilter: nft_set_bitmap: Fix spelling mistake
  netfilter: h323: merge nat hook pointers into one
  netfilter: nf_conntrack: use rcu accessors where needed
  netfilter: nf_conntrack: add missing __rcu annotations
  netfilter: nf_flow_table: count pending offload workqueue tasks
  net/sched: act_ct: set 'net' pointer when creating new nf_flow_table
  netfilter: conntrack: use correct format characters
  netfilter: conntrack: use fallthrough to cleanup
====================

Link: https://lore.kernel.org/r/20220720230754.209053-1-pablo@netfilter.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Saeed Mahameed says:

====================
mlx5-updates-2022-07-17

1) Add resiliency for lost completions for PTP TX port timestamp

2) Report Header-data split state via ethtool

3) Decouple HTB code from main regular TX code

* tag 'mlx5-updates-2022-07-17' of git://git.kernel.org/pub/scm/linux/kernel/git/saeed/linux:
  net/mlx5: CT: Remove warning of ignore_flow_level support for non PF
  net/mlx5e: Add resiliency for PTP TX port timestamp
  net/mlx5: Expose ts_cqe_metadata_size2wqe_counter
  net/mlx5e: HTB, move htb functions to a new file
  net/mlx5e: HTB, change functions name to follow convention
  net/mlx5e: HTB, remove priv from htb function calls
  net/mlx5e: HTB, hide and dynamically allocate mlx5e_htb structure
  net/mlx5e: HTB, move stats and max_sqs to priv
  net/mlx5e: HTB, move section comment to the right place
  net/mlx5e: HTB, move ids to selq_params struct
  net/mlx5e: HTB, reduce visibility of htb functions
  net/mlx5e: Fix mqprio_rl handling on devlink reload
  net/mlx5e: Report header-data split state through ethtool
====================

Link: https://lore.kernel.org/r/20220719203529.51151-1-saeed@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

pr_debug calls are no longer needed in this file.

Pablo suggested "a patch to remove these pr_debug calls". This patch has
some other beneficial collateral as it also silences multiple Clang
-Wformat warnings that were present in the pr_debug calls.

diff from v1 -> v2:
* converted if statement one-liner style
* x == NULL is now !x
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

With refcount_inc_not_zero, we'd also need a smp_rmb or similar,
followed by a test of the CONFIRMED bit.

However, the ct pointer is taken from skb->_nfct, its refcount must
not be 0 (else, we'd already have a use-after-free bug).

Use refcount_inc() instead to clarify the ct refcount is expected to
be at least 1.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them.

It is less verbose and it improves the semantic.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

When a GSI channel is initially allocated, and after it has been
reset, the hardware assumes its ring index is 0.  And although we
do initialize channels this way, the comments in the IPA code don't
really explain this.  For event rings, it doesn't matter what value
we use initially, so using 0 is just fine.

Add some information about the assumptions made by hardware above
the definition of the gsi_ring structure in "gsi.h".

Zero the index field for all rings (channel and event) when the ring
is allocated.  As a result, that function initializes all fields in
the structure.

Stop zeroing the index the top of gsi_channel_program().  Initially
we'll use the index value set when the channel ring was allocated.
And we'll explicitly zero the index value in gsi_channel_reset()
before programming the hardware, adding a comment explaining why
it's required.

For event rings, use the index initialized by gsi_ring_alloc()
rather than 0 when ringing the doorbell in gsi_evt_ring_program().
(It'll still be zero, but we won't assume that to be the case.)

Use a local variable in gsi_evt_ring_program() that represents the
address of the event ring's ring structure.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

For SFP port prestera driver will use kernel
phylink infrastucture to configure port mode based on
the module that has beed inserted
Co-developed-by: Yevhen Orlov <yevhen.orlov@plvision.eu>
Signed-off-by: Yevhen Orlov <yevhen.orlov@plvision.eu>
Co-developed-by: Taras Chornyi <taras.chornyi@plvision.eu>
Signed-off-by: Taras Chornyi <taras.chornyi@plvision.eu>
Signed-off-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some tools (e.g. libxdp) use that information.
Signed-off-by: Andrey Turkin <andrey.turkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'linux-can-next-for-5.20-20220720' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
this is a pull request of 29 patches for net-next/master.

The first 6 patches target the slcan driver. Dan Carpenter contributes
a hardening patch, followed by 5 cleanup patches.

Biju Das contributes 5 patches to prepare the sja1000 driver to
support the Renesas RZ/N1 SJA1000 CAN controller.

Dario Binacchi's patch for the slcan driver fixes a sleep with held
spin lock.

Another patch by Dario Binacchi fixes a wrong comment in the c_can
driver.

Pavel Pisa updates the CTU CAN FD IP core registers.

Stephane Grosjean contributes 3 patches to the peak_usb driver for
cleanups and support of a new MCU.

The last 12 patches are by Vincent Mailhol, they fix and improve the
txerr and rxerr reporting in all CAN drivers.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Vincent Mailhol says:

====================
can: error: set of fixes and improvement on txerr and rxerr reporting

This series is a collection of patches targeting the CAN error
counter. The series is split in three blocks (with small relation to
each other).

Several drivers uses the data[6] and data[7] fields (both of type u8)
of the CAN error frame to report those values. However, the maximum
size an u8 can hold is 255 and the error counter can exceed this value
if bus-off status occurs. As such, the first nine patches of this
series make sure that no drivers try to report txerr or rxerr through
the CAN error frame when bus-off status is reached.

can_frame::data[5..7] are defined as being "controller
specific". Controller specific behaviors are not something desirable
(portability issue...) The tenth patch of this series specifies how
can_frame::data[5..7] should be use and remove any "controller
specific" freedom. The eleventh patch adds a flag to notify though
can_frame::can_id that data[6..7] were populated (in order to be
consistent with other fields).

Finally, the twelfth and last patch add three macro values to specify
the different error counter threshold with so far was hard-coded as
magic numbers in the drivers.

N.B.:
  * patches 1 to 10 are for net (stable).
  * patches 11 and 12 are for net-next (but depends on patches 1 to 10).

** Changelog **

v1 -> v2: https://lore.kernel.org/all/20220712153157.83847-1-mailhol.vincent@wanadoo.fr
  * Fix typo in patch #10: data[7] of CAN error frames is for the RX
    error counter, not the TX one (this is litteraly a one byte
    change).
====================

As discussed take the whole series via can-next -> net-next.

Link: https://lore.kernel.org/all/20220719143550.3681-1-mailhol.vincent@wanadoo.frSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Currently, drivers are using magic numbers to derive the CAN error
states from the error counter. Add three macro declarations to
remediate this.

For reference, the error-active, error-passive and bus-off are defined
in ISO 11898, section 12.1.4.2 "Error counting". Although ISO 11898
does not define error-warning state, this extra value is also commonly
used and is thus also added.

Link: https://lore.kernel.org/all/20220719143550.3681-13-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Add a dedicated flag in uapi/linux/can/error.h to notify the userland
that fields data[6] and data[7] of the CAN error frame were
respectively populated with the tx and rx error counters.

For all driver tree-wide, set up this flags whenever needed.

Link: https://lore.kernel.org/all/20220719143550.3681-12-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Currently, data[5..7] of struct can_frame, when used as a CAN error
frame, are defined as being "controller specific". Device specific
behaviours are problematic because it prevents someone from writing
code which is portable between devices.

As a matter of fact, data[5] is never used, data[6] is always used to
report TX error counter and data[7] is always used to report RX error
counter. can-utils also relies on this.

This patch updates the comment in the uapi header to specify that
data[5] is reserved (and thus should not be used) and that data[6..7]
are used for error counters.

Fixes: 0d66548a ("[CAN]: Add PF_CAN core module")
Link: https://lore.kernel.org/all/20220719143550.3681-11-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 0024d8ad ("can: usb_8dev: Add support for USB2CAN interface from 8 devices")
Link: https://lore.kernel.org/all/20220719143550.3681-10-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 7259124e ("can: kvaser_usb: Split driver into kvaser_usb_core.c and kvaser_usb_leaf.c")
Link: https://lore.kernel.org/all/20220719143550.3681-9-mailhol.vincent@wanadoo.fr
CC: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: aec5fb22 ("can: kvaser_usb: Add support for Kvaser USB hydra family")
Link: https://lore.kernel.org/all/20220719143550.3681-8-mailhol.vincent@wanadoo.fr
CC: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 0738eff1 ("can: Allwinner A10/A20 CAN Controller support - Kernel module")
Link: https://lore.kernel.org/all/20220719143550.3681-7-mailhol.vincent@wanadoo.fr
CC: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 57e83fb9 ("can: hi311x: Add Holt HI-311x CAN driver")
Link: https://lore.kernel.org/all/20220719143550.3681-6-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

alloc_can_err_skb() already sets cf to NULL if the allocation fails [1],
so the redundant cf = NULL assignment gets removed.

[1] https://elixir.bootlin.com/linux/latest/source/drivers/net/can/dev/skb.c#L187

Fixes: 0a9cdcf0 ("can: slcan: extend the protocol with CAN state info")
Link: https://lore.kernel.org/all/20220719143550.3681-5-mailhol.vincent@wanadoo.fr
CC: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 215db185 ("can: sja1000: Consolidate and unify state change handling")
Link: https://lore.kernel.org/all/20220719143550.3681-4-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: fd115931 ("can: add Renesas R-Car CAN driver")
Link: https://lore.kernel.org/all/20220719143550.3681-3-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

During bus off, the error count is greater than 255 and can not fit in
a u8.

Fixes: 0c78ab76 ("pch_can: Add setting TEC/REC statistics processing")
Link: https://lore.kernel.org/all/20220719143550.3681-2-mailhol.vincent@wanadoo.frSigned-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Tony Nguyen says:

====================
1GbE Intel Wired LAN Driver Updates 2022-07-18

This series contains updates to igc driver only.

Kurt Kanzenbach adds support for Qbv schedules where one queue stays open
in consecutive entries.

Sasha removes an unused define and field.

* '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue:
  igc: Remove forced_speed_duplex value
  igc: Remove MSI-X PBA Clear register
  igc: Lift TAPRIO schedule restriction
====================

Link: https://lore.kernel.org/r/20220718180109.4114540-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

the last caller has been removed with commit 96f5e66e ("mac80211: fix
aggregation for hardware with ampdu queues"), so it's safe to remove this
function.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/703d549e3088367651d92a059743f1be848d74b7.1658133689.git.dcaratti@redhat.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Pavel Begunkov says:

====================
io_uring zerocopy send

The patchset implements io_uring zerocopy send. It works with both registered
and normal buffers, mixing is allowed but not recommended. Apart from usual
request completions, just as with MSG_ZEROCOPY, io_uring separately notifies
the userspace when buffers are freed and can be reused (see API design below),
which is delivered into io_uring's Completion Queue. Those "buffer-free"
notifications are not necessarily per request, but the userspace has control
over it and should explicitly attaching a number of requests to a single
notification. The series also adds some internal optimisations when used with
registered buffers like removing page referencing.

From the kernel networking perspective there are two main changes. The first
one is passing ubuf_info into the network layer from io_uring (inside of an
in kernel struct msghdr). This allows extra optimisations, e.g. ubuf_info
caching on the io_uring side, but also helps to avoid cross-referencing
and synchronisation problems. The second part is an optional optimisation
removing page referencing for requests with registered buffers.

Benchmarking UDP with an optimised version of the selftest (see [1]), which
sends a bunch of requests, waits for completions and repeats. "+ flush" column
posts one additional "buffer-free" notification per request, and just "zc"
doesn't post buffer notifications at all.

NIC (requests / second):
IO size | non-zc    | zc             | zc + flush
4000    | 495134    | 606420 (+22%)  | 558971 (+12%)
1500    | 551808    | 577116 (+4.5%) | 565803 (+2.5%)
1000    | 584677    | 592088 (+1.2%) | 560885 (-4%)
600     | 596292    | 598550 (+0.4%) | 555366 (-6.7%)

dummy (requests / second):
IO size | non-zc    | zc             | zc + flush
8000    | 1299916   | 2396600 (+84%) | 2224219 (+71%)
4000    | 1869230   | 2344146 (+25%) | 2170069 (+16%)
1200    | 2071617   | 2361960 (+14%) | 2203052 (+6%)
600     | 2106794   | 2381527 (+13%) | 2195295 (+4%)

Previously it also brought a massive performance speedup compared to the
msg_zerocopy tool (see [3]), which is probably not super interesting. There
is also an additional bunch of refcounting optimisations that was omitted from
the series for simplicity and as they don't change the picture drastically,
they will be sent as follow up, as well as flushing optimisations closing the
performance gap b/w two last columns.

For TCP on localhost (with hacks enabling localhost zerocopy) and including
additional overhead for receive:

IO size | non-zc    | zc
1200    | 4174      | 4148
4096    | 7597      | 11228

Using a real NIC 1200 bytes, zc is worse than non-zc ~5-10%, maybe the
omitted optimisations will somewhat help, should look better for 4000,
but couldn't test properly because of setup problems.

Links:

  liburing (benchmark + tests):
  [1] https://github.com/isilence/liburing/tree/zc_v4

  kernel repo:
  [2] https://github.com/isilence/linux/tree/zc_v4

  RFC v1:
  [3] https://lore.kernel.org/io-uring/cover.1638282789.git.asml.silence@gmail.com/

  RFC v2:
  https://lore.kernel.org/io-uring/cover.1640029579.git.asml.silence@gmail.com/

  Net patches based:
  git@github.com:isilence/linux.git zc_v4-net-base
  or
  https://github.com/isilence/linux/tree/zc_v4-net-base

API design overview:

  The series introduces an io_uring concept of notifactors. From the userspace
  perspective it's an entity to which it can bind one or more requests and then
  requesting to flush it. Flushing a notifier makes it impossible to attach new
  requests to it, and instructs the notifier to post a completion once all
  requests attached to it are completed and the kernel doesn't need the buffers
  anymore.

  Notifications are stored in notification slots, which should be registered as
  an array in io_uring. Each slot stores only one notifier at any particular
  moment. Flushing removes it from the slot and the slot automatically replaces
  it with a new notifier. All operations with notifiers are done by specifying
  an index of a slot it's currently in.

  When registering a notification the userspace specifies a u64 tag for each
  slot, which will be copied in notification completion entries as
  cqe::user_data. cqe::res is 0 and cqe::flags is equal to wrap around u32
  sequence number counting notifiers of a slot.

====================

Link: https://lore.kernel.org/r/cover.1657643355.git.asml.silence@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Teach tcp how to use external ubuf_info provided in msghdr and
also prepare it for managed frags by sprinkling
skb_zcopy_downgrade_managed() when it could mix managed and not managed
frags.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Teach ipv6/udp how to use external ubuf_info provided in msghdr and
also prepare it for managed frags by sprinkling
skb_zcopy_downgrade_managed() when it could mix managed and not managed
frags.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Teach ipv4/udp how to use external ubuf_info provided in msghdr and
also prepare it for managed frags by sprinkling
skb_zcopy_downgrade_managed() when it could mix managed and not managed
frags.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Managed pages contain pinned userspace pages and controlled by upper
layers, there is no need in tracking skb->pfmemalloc for them. Introduce
a helper for filling frags but ignoring page tracking, it'll be needed
later.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Some users like io_uring can do page pinning more efficiently, so we
want a way to delegate referencing to other subsystems. For that add
a new flag called SKBFL_MANAGED_FRAG_REFS. When set, skb doesn't hold
page references and upper layers are responsivle to managing page
lifetime.

It's allowed to convert skbs from managed to normal by calling
skb_zcopy_downgrade_managed(). The function will take all needed
page references and clear the flag. It's needed, for instance,
to avoid mixing managed modes.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add support for custom iov_iter handling to msghdr. The idea is that
in-kernel subsystems want control over how an SG is split.
Signed-off-by: David Ahern <dsahern@kernel.org>
[pavel: move callback into msghdr]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Make possible for network in-kernel callers like io_uring to pass in a
custom ubuf_info by setting it in a new field of struct msghdr.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Link: https://lore.kernel.org/r/cover.1657878101.git.ecree.xilinx@gmail.comSigned-off-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>