Example output looks like:

[   xx.xxxxxx]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)

Some initial machinery for this pretty-printing format has been included
in this patch as well.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Use uppercase CSR names throughout for consistency with the manual
wording, and right-align the keys. The "CSR" part is inferrable from
context, hence dropped for more horizontal space.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Otherwise the addresses wouldn't make sense at all.

While at it, align the "map keys" to maintain right-alignment with the
"estat:" line too; also swap the ERA and ra lines so all CSRs are shown
together.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Show PC (CSR.ERA) in place of $zero, and also show the syscall restart
flag (conveniently stuffed in regs[0]) if non-zero.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Define them according to the ISA manual, in order to enable matching the
sub-exceptions for humanization purposes later.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

While interrupts are assigned ECodes `64 + interrupt number`, all
existing use sites of interrupt numbers want the 64 subtracted.
Re-arrange the definitions so that the actual interrupt number is used
everywhere, and make EXCCODE_INT_END inclusive as it is more intuitive
that way.

While at it, according to the asm/loongarch.h definitions, the total
number of architectural interrupts should be 14, but various other
places indicate otherwise (13 or 15). Those places have been adjusted
to 14 as well for consistency.
Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

LoongArch architecture changes for 6.4 depend on the irq changes
to work on "dual-bridge" systems, so merge them to create a base.

We started disabling '-Warray-bounds' for gcc-12 originally on s390,
because it resulted in some warnings that weren't realistically fixable
(commit 8b202ee2: "s390: disable -Warray-bounds").

That s390-specific issue was then found to be less common elsewhere, but
generic (see f0be87c4: "gcc-12: disable '-Warray-bounds' universally
for now"), and then later expanded the version check was expanded to
gcc-11 (5a41237a: "gcc: disable -Warray-bounds for gcc-11 too").

And it turns out that I was much too optimistic in thinking that it's
all going to go away, and here we are with gcc-13 showing all the same
issues.  So instead of expanding this one version at a time, let's just
disable it for gcc-11+, and put an end limit to it only when we actually
find a solution.

Yes, I'm sure some of this is because the kernel just does odd things
(like our "container_of()" use, but also knowingly playing games with
things like linker tables and array layouts).

And yes, some of the warnings are likely signs of real bugs, but when
there are hundreds of false positives, that doesn't really help.

Oh well.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'kbuild-fixes-v6.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix the prefix in the kernel source tarball

 - Fix a typo in the copyright file in Debian package

* tag 'kbuild-fixes-v6.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: use proper prefix for tarballs to fix rpm-pkg build error
  kbuild: deb-pkg: Fix a spell typo in mkdebian script

Pull irq fix from Borislav Petkov:

 - Remove an over-zealous sanity check of the array of MSI-X vectors to
   be allocated for a device

* tag 'irq_urgent_for_v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  PCI/MSI: Remove over-zealous hardware size check in pci_msix_validate_entries()

Pull x86 fix from Borislav Petkov

 - Fix for older binutils which do not support C-syntax constant
   suffixes

* tag 'x86_urgent_for_v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternatives: Do not use integer constant suffixes in inline asm

Pull input fixes from Dmitry Torokhov:

 - a check in pegasus-notetaker driver to validate the type of pipe when
   probing a new device

 - a fix for Cypress touch controller to correctly parse maximum number
   of touches.

* tag 'input-for-v6.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: cyttsp5 - fix sensing configuration data structure
  Input: pegasus-notetaker - check pipe type when probing

Since commit f8d94c4e ("kbuild: do not create intermediate *.tar
for source tarballs"), 'make rpm-pkg' fails because the prefix of the
source tarball is 'linux.tar/' instead of 'linux/'. $(basename $@)
strips only '.gz' from the filename linux.tar.gz.

You need to strip two suffixes from compressed tarballs and one suffix
from uncompressed tarballs (for example 'perf-6.3.0.tar' generated by
'make perf-tar-src-pkg').

One tricky fix might be --prefix=$(firstword $(subst .tar, ,$@))/
but I think it is better to hard-code the prefix.

Fixes: f8d94c4e ("kbuild: do not create intermediate *.tar for source tarballs")
Reported-by: Jiwei Sun <sunjw10@lenovo.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

Signed-off-by: Woody Suwalski <terraluna977@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

Pull MIPS fix from Thomas Bogendoerfer:
 "Fix for link errors"

* tag 'mips-fixes_6.3_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Define RUNTIME_DISCARD_EXIT in LD script

Pull kvm fixes from Paolo Bonzini:
 "Two serious ARM fixes:

   - Plug a buffer overflow due to the use of the user-provided register
     width for firmware regs. Outright reject accesses where the user
     register width does not match the kernel representation.

   - Protect non-atomic RMW operations on vCPU flags against preemption,
     as an update to the flags by an intervening preemption could be
     lost"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: arm64: Fix buffer overflow in kvm_arm_set_fw_reg()
  KVM: arm64: Make vcpu flag updates non-preemptible

Pull cifs fixes from Steve French:
 "Three small smb3 client fixes:

   - two important fixes for unbuffered read regression with the
     iov_iter changes (e.g. read soon after mount in some multichannel
     scenarios)

   - DFS prefix path fix (also for stable)"

* tag '6.3-rc7-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Reapply lost fix from commit 30b2b219
  cifs: Fix unbuffered read
  cifs: avoid dup prefix path in dfs_get_automount_devname()

Merge tag 'kvmarm-fixes-6.3-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 fixes for 6.3, part #4

 - Plug a buffer overflow due to the use of the user-provided register
   width for firmware regs. Outright reject accesses where the
   user register width does not match the kernel representation.

 - Protect non-atomic RMW operations on vCPU flags against preemption,
   as an update to the flags by an intervening preemption could be lost.

MIPS's exit sections are discarded at runtime as well.

Fixes link error:
`.exit.text' referenced in section `__jump_table' of fs/fuse/inode.o:
defined in discarded section `.exit.text' of fs/fuse/inode.o

Fixes: 99cb0d91 ("arch: fix broken BuildID for arm64 and riscv")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

This reverts commit 5c62d5aa.

This broke wake-on-lan for multiple people, and for much too long.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217069
Link: https://lore.kernel.org/all/754225a2-95a9-2c36-1886-7da1a78308c2@loongson.cn/
Link: https://github.com/acpica/acpica/pull/866
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Jianmin Lv <lvjianmin@loongson.cn>
Cc: Huacai Chen <chenhuacai@loongson.cn>
Cc: Bob Moore <robert.moore@intel.com>
Cc: stable@kernel.org # 6.2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull btrfs fixes from David Sterba:
 "Two patches fixing the problem with aync discard.

  The default settings had a low IOPS limit and processing a large batch
  to discard would take a long time. On laptops this can cause increased
  power consumption due to disk activity.

  As async discard has been on by default since 6.2 this likely affects
  a lot of users.

  Summary:

   - increase the default IOPS limit 10x which reportedly helped

   - setting the sysfs IOPS value to 0 now does not throttle anymore
     allowing the discards to be processed at full speed. Previously
     there was an arbitrary 6 hour target for processing the pending
     batch"

* tag 'for-6.3-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: reinterpret async discard iops_limit=0 as no delay
  btrfs: set default discard iops_limit to 1000

Pull block fix from Jens Axboe:
 "Just a single revert of a patch from the 6.3 series"

* tag 'block-6.3-2023-04-21' of git://git.kernel.dk/linux:
  Revert "block: Merge bio before checking ->cached_rq"

Pull char/misc driver fixes from Greg KH:
 "Here are some last-minute tiny driver fixes for 6.3-final. They
  include fixes for some fpga and iio drivers:

   - fpga bridge driver fix

   - fpga dfl error reporting fix

   - fpga m10bmc driver fix

   - fpga xilinx driver fix

   - iio light driver fix

   - iio dac fwhandle leak fix

   - iio adc driver fix

  All of these have been in linux-next for a few weeks with no reported
  problems"

* tag 'char-misc-6.3-final' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  iio: light: tsl2772: fix reading proximity-diodes from device tree
  fpga: bridge: properly initialize bridge device before populating children
  iio: dac: ad5755: Add missing fwnode_handle_put()
  iio: adc: at91-sama5d2_adc: fix an error code in at91_adc_allocate_trigger()
  fpga: xilinx-pr-decoupler: Use readl wrapper instead of pure readl
  fpga: dfl-pci: Drop redundant pci_enable_pcie_error_reporting()
  fpga: m10bmc-sec: Fix rsu_send_data() to return FW_UPLOAD_ERR_HW_ERROR

Pull gpio fixes from Bartosz Golaszewski:

 - use raw_spinlocks in regmaps that are used in interrupt context in
   gpio-104-idi-48 and gpio-104-dio-48e

* tag 'gpio-fixes-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: 104-idi-48: Enable use_raw_spinlock for idi48_regmap_config
  gpio: 104-dio-48e: Enable use_raw_spinlock for dio48e_regmap_config

Pull sound fixes from Takashi Iwai:
 "Just a few fixes: all small and device-specific (ASoC FSL, SOF, and
  HD-audio quirks), should be safe to apply at the last minute"

* tag 'sound-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek: fix mute/micmute LEDs for a HP ProBook
  ASoC: fsl_asrc_dma: fix potential null-ptr-deref
  ASoC: fsl_sai: Fix pins setting for i.MX8QM platform
  ALSA: hda/realtek: Remove specific patch for Dell Precision 3260
  ASoC: max98373: change power down sequence for smart amp
  ASoC: SOF: pm: Tear down pipelines only if DSP was active
  ASoC: SOF: ipc4-topology: Clarify bind failure caused by missing fw_module

It seems there is a misprint in the check of strdup() return code that
can lead to NULL pointer dereference.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 4520c6a4 ("X.509: Add simple ASN.1 grammar compiler")
Signed-off-by: Ekaterina Orlova <vorobushek.ok@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: keyrings@vger.kernel.org
Cc: linux-kbuild@vger.kernel.org
Link: https://lore.kernel.org/r/20230315172130.140-1-vorobushek.ok@gmail.com/Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull drm fixes from Dave Airlie:
 "This is the regular and hopefully last round of fixes for 6.3.

  Pretty small, a few amdgpu, one i915, one nouveau, one rockchip and
  one gpu scheduler fix:

  nouveau:
   - fix dma-resv timeout

  rockchip:
   - fix suspend/resume

  sched:
   - fix timeout handling

  i915:
   - Fix fast wake AUX sync len

  amdgpu:
   - GPU reset fix
   - DCN 3.1.5 line buffer fix
   - Display fix for single channel memory configs
   - Fix a possible divide by 0"

* tag 'drm-fixes-2023-04-21' of git://anongit.freedesktop.org/drm/drm:
  drm/amd/display: fix a divided-by-zero error
  drm/amd/display: limit timing for single dimm memory
  drm/amd/display: set dcn315 lb bpp to 48
  drm/amdgpu: Fix desktop freezed after gpu-reset
  drm/rockchip: vop2: Use regcache_sync() to fix suspend/resume
  drm/nouveau: fix incorrect conversion to dma_resv_wait_timeout()
  drm/rockchip: vop2: fix suspend/resume
  drm/i915: Fix fast wake AUX sync len
  drm/sched: Check scheduler ready before calling timeout handling

Merge tag 'amd-drm-fixes-6.3-2023-04-19' of https://gitlab.freedesktop.org/agd5f/linux into drm-fixes

amd-drm-fixes-6.3-2023-04-19:

amdgpu:
- GPU reset fix
- DCN 3.1.5 line buffer fix
- Display fix for single channel memory configs
- Fix a possible divide by 0
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230420031717.7790-1-alexander.deucher@amd.com

Merge tag 'drm-intel-fixes-2023-04-19' of git://anongit.freedesktop.org/drm/drm-intel into drm-fixes

drm/i915 fixes for v6.3 final:
- Fix fast wake AUX sync len
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/87354w1b76.fsf@intel.com

Merge tag 'drm-misc-fixes-2023-04-20-2' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

Short summary of fixes pull:

 * nouveau: fix dma-resv timeout
 * rockchip: fix suspend/resume
 * sched: fix timeout handling
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230420083114.GA17651@linux-uq9g

Pull pci fix from Bjorn Helgaas:

 - Previously we ignored PCI devices if the DT "status" property or the
   ACPI _STA method said it was not present.

   Per spec, _STA cannot be used for that purpose, and using it that way
   caused regressions, so skip the _STA check (Rob Herring)

* tag 'pci-v6.3-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
  PCI: Restrict device disabled status check to DT

Currently, a limit of 0 results in a hard coded metering over 6 hours.
Since the default is a set limit, I suspect no one truly depends on this
rather arbitrary setting. Repurpose it for an arguably more useful
"unlimited" mode, where the delay is 0.

Note that if block groups are too new, or go fully empty, there is still
a delay associated with those conditions. Those delays implement
heuristics for not trimming a region we are relatively likely to fully
overwrite soon.

CC: stable@vger.kernel.org # 6.2+
Reviewed-by: Neal Gompa <neal@gompa.dev>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Previously, the default was a relatively conservative 10. This results
in a 100ms delay, so with ~300 discards in a commit, it takes the full
30s till the next commit to finish the discards. On a workstation, this
results in the disk never going idle, wasting power/battery, etc.

Set the default to 1000, which results in using the smallest possible
delay, currently, which is 1ms. This has shown to not pathologically
keep the disk busy by the original reporter.

Link: https://lore.kernel.org/linux-btrfs/Y%2F+n1wS%2F4XAH7X1p@nz/
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2182228
CC: stable@vger.kernel.org # 6.2+
Reviewed-by: Neal Gompa <neal@gompa.dev
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

This partially reverts commit e161d4b6.

Turns out the channelmap variable is not actually read-only, it's modified
through the MCI_GPM_CLR_CHANNEL_BIT() macro further down in the function,
so making it read-only causes page faults when that code is hit.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217183
Link: https://lore.kernel.org/r/20230413214118.153781-1-toke@toke.dk
Fixes: e161d4b6 ("wifi: ath9k: Make arrays prof_prio and channelmap static const")
Cc: stable@vger.kernel.org
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull Rust fixes from Miguel Ojeda:
 "Most of these are straightforward.

  The last one is more complex, but it only touches Rust + GCC builds
  which are for the moment best-effort.

   - Code: Missing 'extern "C"' fix.

   - Scripts: 'is_rust_module.sh' and 'generate_rust_analyzer.py' fixes.

   - A couple trivial fixes

   - Build: Rust + GCC build fix and 'grep' warning fix"

* tag 'rust-fixes-6.3' of https://github.com/Rust-for-Linux/linux:
  rust: allow to use INIT_STACK_ALL_ZERO
  rust: fix regexp in scripts/is_rust_module.sh
  rust: build: Fix grep warning
  scripts: generate_rust_analyzer: Handle sub-modules with no Makefile
  rust: kernel: Mark rust_fmt_argument as extern "C"
  rust: sort uml documentation arch support table
  rust: str: fix requierments->requirements typo

Commit 6fffbc7a ("PCI: Honor firmware's device disabled status")
checked the firmware device status for both DT and ACPI devices. That
caused a regression in some ACPI systems. The exact reason isn't clear.
It's possibly a firmware bug. For now, at least, refactor the check to
be for DT based systems only.

Note that the original implementation leaked a refcount which is now
correctly handled.

[bhelgaas: Per ACPI r6.5, sec 6.3.7, for devices on an enumerable bus, _STA
must return with bit[0] ("device is present") set]

Link: https://lore.kernel.org/all/m2fs9lgndw.fsf@gmail.com/
Fixes: 6fffbc7a ("PCI: Honor firmware's device disabled status")
Link: https://lore.kernel.org/r/20230419193513.708818-1-robh@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217317Reported-by: Donald Hunter <donald.hunter@gmail.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Tested-by: Donald Hunter <donald.hunter@gmail.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Binbin Zhou <zhoubinbin@loongson.cn>
Cc: Liu Peibao <liupeibao@loongson.cn>
Cc: Huacai Chen <chenhuacai@loongson.cn>

Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter and bpf.

  There are a few fixes for new code bugs, including the Mellanox one
  noted in the last networking pull. No known regressions outstanding.

  Current release - regressions:

   - sched: clear actions pointer in miss cookie init fail

   - mptcp: fix accept vs worker race

   - bpf: fix bpf_arch_text_poke() with new_addr == NULL on s390

   - eth: bnxt_en: fix a possible NULL pointer dereference in unload
     path

   - eth: veth: take into account peer device for
     NETDEV_XDP_ACT_NDO_XMIT xdp_features flag

  Current release - new code bugs:

   - eth: revert "net/mlx5: Enable management PF initialization"

  Previous releases - regressions:

   - netfilter: fix recent physdev match breakage

   - bpf: fix incorrect verifier pruning due to missing register
     precision taints

   - eth: virtio_net: fix overflow inside xdp_linearize_page()

   - eth: cxgb4: fix use after free bugs caused by circular dependency
     problem

   - eth: mlxsw: pci: fix possible crash during initialization

  Previous releases - always broken:

   - sched: sch_qfq: prevent slab-out-of-bounds in qfq_activate_agg

   - netfilter: validate catch-all set elements

   - bridge: don't notify FDB entries with "master dynamic"

   - eth: bonding: fix memory leak when changing bond type to ethernet

   - eth: i40e: fix accessing vsi->active_filters without holding lock

  Misc:

   - Mat is back as MPTCP co-maintainer"

* tag 'net-6.3-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (33 commits)
  net: bridge: switchdev: don't notify FDB entries with "master dynamic"
  Revert "net/mlx5: Enable management PF initialization"
  MAINTAINERS: Resume MPTCP co-maintainer role
  mailmap: add entries for Mat Martineau
  e1000e: Disable TSO on i219-LM card to increase speed
  bnxt_en: fix free-runnig PHC mode
  net: dsa: microchip: ksz8795: Correctly handle huge frame configuration
  bpf: Fix incorrect verifier pruning due to missing register precision taints
  hamradio: drop ISA_DMA_API dependency
  mlxsw: pci: Fix possible crash during initialization
  mptcp: fix accept vs worker race
  mptcp: stops worker on unaccepted sockets at listener close
  net: rpl: fix rpl header size calculation
  net: vmxnet3: Fix NULL pointer dereference in vmxnet3_rq_rx_complete()
  bonding: Fix memory leak when changing bond type to Ethernet
  veth: take into account peer device for NETDEV_XDP_ACT_NDO_XMIT xdp_features flag
  mlxfw: fix null-ptr-deref in mlxfw_mfa2_tlv_next()
  bnxt_en: Fix a possible NULL pointer dereference in unload path
  bnxt_en: Do not initialize PTP on older P3/P4 chips
  netfilter: nf_tables: tighten netlink attribute requirements for catch-all elements
  ...

This reverts commit 23f3e327.

blk-mq sched bio merge still needs request to grab queue usage counter,
so we can't simply call blk_mq_attempt_bio_merge() when queue usage
counter isn't held.

Fixes: 23f3e327 ("block: Merge bio before checking ->cached_rq")
Cc: Xiao Ni <xni@redhat.com>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230420112018.1108058-1-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

There is a structural problem in switchdev, where the flag bits in
struct switchdev_notifier_fdb_info (added_by_user, is_local etc) only
represent a simplified / denatured view of what's in struct
net_bridge_fdb_entry :: flags (BR_FDB_ADDED_BY_USER, BR_FDB_LOCAL etc).
Each time we want to pass more information about struct
net_bridge_fdb_entry :: flags to struct switchdev_notifier_fdb_info
(here, BR_FDB_STATIC), we find that FDB entries were already notified to
switchdev with no regard to this flag, and thus, switchdev drivers had
no indication whether the notified entries were static or not.

For example, this command:

ip link add br0 type bridge && ip link set swp0 master br0
bridge fdb add dev swp0 00:01:02:03:04:05 master dynamic

has never worked as intended with switchdev. It causes a struct
net_bridge_fdb_entry to be passed to br_switchdev_fdb_notify() which has
a single flag set: BR_FDB_ADDED_BY_USER.

This is further passed to the switchdev notifier chain, where interested
drivers have no choice but to assume this is a static (does not age) and
sticky (does not migrate) FDB entry. So currently, all drivers offload
it to hardware as such, as can be seen below ("offload" is set).

bridge fdb get 00:01:02:03:04:05 dev swp0 master
00:01:02:03:04:05 dev swp0 offload master br0

The software FDB entry expires $ageing_time centiseconds after the
kernel last sees a packet with this MAC SA, and the bridge notifies its
deletion as well, so it eventually disappears from hardware too.

This is a problem, because it is actually desirable to start offloading
"master dynamic" FDB entries correctly - they should expire $ageing_time
centiseconds after the *hardware* port last sees a packet with this
MAC SA - and this is how the current incorrect behavior was discovered.
With an offloaded data plane, it can be expected that software only sees
exception path packets, so an otherwise active dynamic FDB entry would
be aged out by software sooner than it should.

With the change in place, these FDB entries are no longer offloaded:

bridge fdb get 00:01:02:03:04:05 dev swp0 master
00:01:02:03:04:05 dev swp0 master br0

and this also constitutes a better way (assuming a backport to stable
kernels) for user space to determine whether the kernel has the
capability of doing something sane with these or not.

As opposed to "master dynamic" FDB entries, on the current behavior of
which no one currently depends on (which can be deduced from the lack of
kselftests), Ido Schimmel explains that entries with the "extern_learn"
flag (BR_FDB_ADDED_BY_EXT_LEARN) should still be notified to switchdev,
since the spectrum driver listens to them (and this is kind of okay,
because although they are treated identically to "static", they are
expected to not age, and to roam).

Fixes: 6b26b51b ("net: bridge: Add support for notifying devices about FDB add/del")
Link: https://lore.kernel.org/netdev/20230327115206.jk5q5l753aoelwus@skbuf/Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20230418155902.898627-1-vladimir.oltean@nxp.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>