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>

During the refactoring for the ksz8_dev_ops from ksz8795.c to
ksz_common.c, the ksz8_r_mib_cnt has been missed. So this patch adds the
missing one.

Fixes: 6ec23aaa ("net: dsa: microchip: move ksz_dev_ops to ksz_common.c")
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220718061803.4939-1-arun.ramadoss@microchip.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Propagate ingress/egress direction for 'police' action down to hardware.
Co-developed-by: Volodymyr Mytnyk <volodymyr.mytnyk@plvision.eu>
Signed-off-by: Volodymyr Mytnyk <volodymyr.mytnyk@plvision.eu>
Signed-off-by: Maksym Glubokiy <maksym.glubokiy@plvision.eu>
Link: https://lore.kernel.org/r/20220714083541.1973919-1-maksym.glubokiy@plvision.euSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Tony Nguyen says:

====================
100GbE Intel Wired LAN Driver Updates 2022-07-15

This series contains updates to ice driver only.

Ani updates feature restriction for devices that don't support external
time stamping.

Zhuo Chen removes unnecessary call to pci_aer_clear_nonfatal_status().

* '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue:
  ice: Remove pci_aer_clear_nonfatal_status() call
  ice: Add EXTTS feature to the feature bitmap
====================

Link: https://lore.kernel.org/r/20220715214642.2968799-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The port fields in the ethool flow structures are defined
to be __be16 types, so sparse is showing issues where these
are being passed to htons(). Fix these warnings by passing
them to be16_to_cpu() instead.

These are being used in netdev_dbg() so should only effect
anyone doing debug.

Fixes the following sparse warnings:

drivers/net/ethernet/cadence/macb_main.c:3366:9: warning: cast from restricted __be16
drivers/net/ethernet/cadence/macb_main.c:3366:9: warning: cast from restricted __be16
drivers/net/ethernet/cadence/macb_main.c:3366:9: warning: cast from restricted __be16
drivers/net/ethernet/cadence/macb_main.c:3419:25: warning: cast from restricted __be16
drivers/net/ethernet/cadence/macb_main.c:3419:25: warning: cast from restricted __be16
drivers/net/ethernet/cadence/macb_main.c:3419:25: warning: cast from restricted __be16
drivers/net/ethernet/cadence/macb_main.c:3419:25: warning: cast from restricted __be16
Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Link: https://lore.kernel.org/r/20220715173009.526126-1-ben.dooks@sifive.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Make the code look better.
Signed-off-by: Maksym Glubokiy <maksym.glubokiy@plvision.eu>
Link: https://lore.kernel.org/r/20220715103806.7108-1-maksym.glubokiy@plvision.euSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Make generic XDP processing attribute packets to their actual
queues instead of queue #0. This improves AF_XDP performance
considerably since softirq threads no longer fight over single
AF_XDP socket spinlock.
Signed-off-by: Andrey Turkin <andrey.turkin@gmail.com>
Link: https://lore.kernel.org/r/20220717022050.822766-2-andrey.turkin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Jiri Pirko says:

====================
devlink: prepare mlxsw and netdevsim for locked reload

This is preparation patchset to be able to eventually make a switch and
make reload cmd to take devlink->lock as the other commands do.

This patchset is preparing 2 major users of devlink API - mlxsw and
netdevsim. The sets of functions are similar, therefore taking care of
both here.
====================

Link: https://lore.kernel.org/r/20220716110241.3390528-1-jiri@resnulli.usSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Remove locked versions of functions that are no longer used by anyone.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Prepare for devlink reload being called with devlink->lock held and
convert the netdevsim driver to use unlocked devlink API during init and
fini flows. Take devl_lock() in reload_down() and reload_up() ops in the
meantime before reload cmd is converted to take the lock itself.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add unlocked variants of devlink_region_create/destroy() functions
to be used in drivers called-in with devlink->lock held.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Prepare for devlink reload being called with devlink->lock held and
convert the mlxsw driver to use unlocked devlink API during init and
fini flows. Take devl_lock() in reload_down() and reload_up() ops in the
meantime before reload cmd is converted to take the lock itself.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add unlocked variants of devlink_dpipe*() functions to be used
in drivers called-in with devlink->lock held.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add unlocked variants of devlink_sb*() functions to be used
in drivers called-in with devlink->lock held.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add unlocked variants of devlink_resource*() functions to be used
in drivers called-in with devlink->lock held.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add unlocked variants of devl_trap*() functions to be used in drivers
called-in with devlink->lock held.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Add a lock_class_key per devlink instance to avoid DEADLOCK warning by
lockdep, while locking more than one devlink instance in driver code,
for example in opening VFs flow.

Kernel log:
[  101.433802] ============================================
[  101.433803] WARNING: possible recursive locking detected
[  101.433810] 5.19.0-rc1+ #35 Not tainted
[  101.433812] --------------------------------------------
[  101.433813] bash/892 is trying to acquire lock:
[  101.433815] ffff888127bfc2f8 (&devlink->lock){+.+.}-{3:3}, at: probe_one+0x3c/0x690 [mlx5_core]
[  101.433909]
               but task is already holding lock:
[  101.433910] ffff888118f4c2f8 (&devlink->lock){+.+.}-{3:3}, at: mlx5_core_sriov_configure+0x62/0x280 [mlx5_core]
[  101.433989]
               other info that might help us debug this:
[  101.433990]  Possible unsafe locking scenario:

[  101.433991]        CPU0
[  101.433991]        ----
[  101.433992]   lock(&devlink->lock);
[  101.433993]   lock(&devlink->lock);
[  101.433995]
                *** DEADLOCK ***

[  101.433996]  May be due to missing lock nesting notation

[  101.433996] 6 locks held by bash/892:
[  101.433998]  #0: ffff88810eb50448 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0xf3/0x1d0
[  101.434009]  #1: ffff888114777c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x20d/0x520
[  101.434017]  #2: ffff888102b58660 (kn->active#231){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x230/0x520
[  101.434023]  #3: ffff888102d70198 (&dev->mutex){....}-{3:3}, at: sriov_numvfs_store+0x132/0x310
[  101.434031]  #4: ffff888118f4c2f8 (&devlink->lock){+.+.}-{3:3}, at: mlx5_core_sriov_configure+0x62/0x280 [mlx5_core]
[  101.434108]  #5: ffff88812adce198 (&dev->mutex){....}-{3:3}, at: __device_attach+0x76/0x430
[  101.434116]
               stack backtrace:
[  101.434118] CPU: 5 PID: 892 Comm: bash Not tainted 5.19.0-rc1+ #35
[  101.434120] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[  101.434130] Call Trace:
[  101.434133]  <TASK>
[  101.434135]  dump_stack_lvl+0x57/0x7d
[  101.434145]  __lock_acquire.cold+0x1df/0x3e7
[  101.434151]  ? register_lock_class+0x1880/0x1880
[  101.434157]  lock_acquire+0x1c1/0x550
[  101.434160]  ? probe_one+0x3c/0x690 [mlx5_core]
[  101.434229]  ? lockdep_hardirqs_on_prepare+0x400/0x400
[  101.434232]  ? __xa_alloc+0x1ed/0x2d0
[  101.434236]  ? ksys_write+0xf3/0x1d0
[  101.434239]  __mutex_lock+0x12c/0x14b0
[  101.434243]  ? probe_one+0x3c/0x690 [mlx5_core]
[  101.434312]  ? probe_one+0x3c/0x690 [mlx5_core]
[  101.434380]  ? devlink_alloc_ns+0x11b/0x910
[  101.434385]  ? mutex_lock_io_nested+0x1320/0x1320
[  101.434388]  ? lockdep_init_map_type+0x21a/0x7d0
[  101.434391]  ? lockdep_init_map_type+0x21a/0x7d0
[  101.434393]  ? __init_swait_queue_head+0x70/0xd0
[  101.434397]  probe_one+0x3c/0x690 [mlx5_core]
[  101.434467]  pci_device_probe+0x1b4/0x480
[  101.434471]  really_probe+0x1e0/0xaa0
[  101.434474]  __driver_probe_device+0x219/0x480
[  101.434478]  driver_probe_device+0x49/0x130
[  101.434481]  __device_attach_driver+0x1b8/0x280
[  101.434484]  ? driver_allows_async_probing+0x140/0x140
[  101.434487]  bus_for_each_drv+0x123/0x1a0
[  101.434489]  ? bus_for_each_dev+0x1a0/0x1a0
[  101.434491]  ? lockdep_hardirqs_on_prepare+0x286/0x400
[  101.434494]  ? trace_hardirqs_on+0x2d/0x100
[  101.434498]  __device_attach+0x1a3/0x430
[  101.434501]  ? device_driver_attach+0x1e0/0x1e0
[  101.434503]  ? pci_bridge_d3_possible+0x1e0/0x1e0
[  101.434506]  ? pci_create_resource_files+0xeb/0x190
[  101.434511]  pci_bus_add_device+0x6c/0xa0
[  101.434514]  pci_iov_add_virtfn+0x9e4/0xe00
[  101.434517]  ? trace_hardirqs_on+0x2d/0x100
[  101.434521]  sriov_enable+0x64a/0xca0
[  101.434524]  ? pcibios_sriov_disable+0x10/0x10
[  101.434528]  mlx5_core_sriov_configure+0xab/0x280 [mlx5_core]
[  101.434602]  sriov_numvfs_store+0x20a/0x310
[  101.434605]  ? sriov_totalvfs_show+0xc0/0xc0
[  101.434608]  ? sysfs_file_ops+0x170/0x170
[  101.434611]  ? sysfs_file_ops+0x117/0x170
[  101.434614]  ? sysfs_file_ops+0x170/0x170
[  101.434616]  kernfs_fop_write_iter+0x348/0x520
[  101.434619]  new_sync_write+0x2e5/0x520
[  101.434621]  ? new_sync_read+0x520/0x520
[  101.434624]  ? lock_acquire+0x1c1/0x550
[  101.434626]  ? lockdep_hardirqs_on_prepare+0x400/0x400
[  101.434630]  vfs_write+0x5cb/0x8d0
[  101.434633]  ksys_write+0xf3/0x1d0
[  101.434635]  ? __x64_sys_read+0xb0/0xb0
[  101.434638]  ? lockdep_hardirqs_on_prepare+0x286/0x400
[  101.434640]  ? syscall_enter_from_user_mode+0x1d/0x50
[  101.434643]  do_syscall_64+0x3d/0x90
[  101.434647]  entry_SYSCALL_64_after_hwframe+0x46/0xb0
[  101.434650] RIP: 0033:0x7f5ff536b2f7
[  101.434658] Code: 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f
1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f
05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
[  101.434661] RSP: 002b:00007ffd9ea85d58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  101.434664] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f5ff536b2f7
[  101.434666] RDX: 0000000000000002 RSI: 000055c4c279e230 RDI: 0000000000000001
[  101.434668] RBP: 000055c4c279e230 R08: 000000000000000a R09: 0000000000000001
[  101.434669] R10: 000055c4c283cbf0 R11: 0000000000000246 R12: 0000000000000002
[  101.434670] R13: 00007f5ff543d500 R14: 0000000000000002 R15: 00007f5ff543d700
[  101.434673]  </TASK>
Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We don't want to list every single ubuf_info callback in
skb_orphan_frags(), add a flag controlling the behaviour.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We should not append MSG_ZEROCOPY requests to skbuff with non
MSG_ZEROCOPY ubuf_info, they might be not compatible.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Even when zerocopy transmission is requested and possible,
__ip_append_data() will still copy a small chunk of data just because it
allocated some extra linear space (e.g. 128 bytes). It wastes CPU cycles
on copy and iter manipulations and also misalignes potentially aligned
data. Avoid such copies. And as a bonus we can allocate smaller skb.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Even when zerocopy transmission is requested and possible,
__ip_append_data() will still copy a small chunk of data just because it
allocated some extra linear space (e.g. 148 bytes). It wastes CPU cycles
on copy and iter manipulations and also misalignes potentially aligned
data. Avoid such copies. And as a bonus we can allocate smaller skb.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Use netif_napi_add_tx() for NAPI in Tx direction instead of the regular
netif_napi_add() function.
Signed-off-by: Sieng-Piaw Liew <liew.s.piaw@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch removes the of_match_ptr() pointer when dereferencing the
ksz_dt_ids which produce the unused variable warning.
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
tls: rx: avoid skb_cow_data()

TLS calls skb_cow_data() on the skb it received from strparser
whenever it needs to hold onto the skb with the decrypted data.
(The alternative being decrypting directly to a user space buffer
in whic case the input skb doesn't get modified or used after.)
TLS needs the decrypted skb:
 - almost always with TLS 1.3 (unless the new NoPad is enabled);
 - when user space buffer is too small to fit the record;
 - when BPF sockmap is enabled.

Most of the time the skb we get out of strparser is a clone of
a 64kB data unit coalsced by GRO. To make things worse skb_cow_data()
tries to output a linear skb and allocates it with GFP_ATOMIC.
This occasionally fails even under moderate memory pressure.

This patch set rejigs the TLS Rx so that we don't expect decryption
in place. The decryption handlers return an skb which may or may not
be the skb from strparser. For TLS 1.3 this results in a 20-30%
performance improvement without NoPad enabled.

v2: rebase after 3d8c51b2 ("net/tls: Check for errors in tls_device_init")
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

We currently CoW Rx skbs whenever we can't decrypt to a user
space buffer. The skbs can be enormous (64kB) and CoW does
a linear alloc which has a strong chance of failing under
memory pressure. Or even without, skb_cow_data() assumes
GFP_ATOMIC.

Allocate a new frag'd skb and decrypt into it. We finally
take advantage of the decrypted skb getting returned via
darg.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The "zero-copy" path in SW TLS will engage either for no skbs or
for all but last. If the recvmsg parameters are right and the
socket can do ZC we'll ZC until the iterator can't fit a full
record at which point we'll decrypt one more record and copy
over the necessary bits to fill up the request.

The only reason we hold onto the ZC skbs which went thru the async
path until the end of recvmsg() is to count bytes. We need an accurate
count of zc'ed bytes so that we can calculate how much of the non-zc'd
data to copy. To allow freeing input skbs on the ZC path count only
how much of the list we'll need to consume.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Async crypto currently benefits from the fact that we decrypt
in place. When we allow input and output to be different skbs
we will have to hang onto the input while we move to the next
record. Clone the inputs and keep them on a list.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Async crypto TLS Rx currently waits for crypto to be done
in order to strip the TLS header and tailer. Simplify
the code by moving the pointers immediately, since only
TLS 1.2 is supported here there is no message padding.

This simplifies the decryption into a new skb in the next
patch as we don't have to worry about input vs output
skb in the decrypt_done() handler any more.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using ctx->recv_pkt after decryption read the skb
from darg.skb. This moves the decision of what the "output skb"
is to the decrypt handlers. For now after decrypt handler returns
successfully ctx->recv_pkt is simply moved to darg.skb, but it
will change soon.

Note that tls_decrypt_sg() cannot clear the ctx->recv_pkt
because it gets called to re-encrypt (i.e. by the device offload).
So we need an awkward temporary if() in tls_rx_one_record().
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Callers always pass ctx->recv_pkt into decrypt_skb_update(),
and it propagates it to its callees. This may give someone
the false impression that those functions can accept any valid
skb containing a TLS record. That's not the case, the record
sequence number is read from the context, and they can only
take the next record coming out of the strp.

Let the functions get the skb from the context instead of
passing it in. This will also make it cleaner to return
a different skb than ctx->recv_pkt as the decrypted one
later on.

Since we're touching the definition of decrypt_skb_update()
use this as an opportunity to rename it.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

I already forgot to transform darg from input to output
semantics once on the NIC inline crypto fastpath. To
avoid this happening again create a device equivalent
of decrypt_internal(). A function responsible for decryption
and transforming darg.

While at it rename decrypt_internal() to a hopefully slightly
more meaningful name.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>