This is a follow up of commit 3226b158
("net: avoid 32 x truesize under-estimation for tiny skbs")

When/if we increase MAX_SKB_FRAGS, we better make sure
the old bug will not come back.

Adding a check in napi_get_frags() would be costly,
even if using DEBUG_NET_WARN_ON_ONCE().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Commit 6454eca8 ("net: Use lockdep_assert_in_softirq()
in napi_consume_skb()") added a check in napi_consume_skb()
which is a bit weak.

napi_consume_skb() and __napi_alloc_skb() should only
be used from BH context, not from hard irq or nmi context,
otherwise we could have races.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Remove this check from fast path unless CONFIG_DEBUG_NET=y
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Replace four WARN_ON() that have not triggered recently
with DEBUG_NET_WARN_ON_ONCE().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sk_stream_kill_queues() has three checks which have been
useful to detect kernel bugs in the past.

However they are potentially a problem because they
could flood the syslog.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

inet_sock_destruct() has four warnings which have been
useful to point to kernel bugs in the past.

However they are potentially a problem because they
could flood the syslog.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

One check in dev_loopback_xmit() has not caught issues
in the past.

Keep it for CONFIG_DEBUG_NET=y builds only.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Check against skb dst in socket backlog has never triggered
in past years.

Keep the check omly for CONFIG_DEBUG_NET=y builds.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Eric Dumazet says:

====================
net: adopt u64_stats_t type

While KCSAN has not raised any reports yet, we should address the
potential load/store tearing problem happening with per cpu stats.

This series is not exhaustive, but hopefully a step in the right
direction.
====================

Link: https://lore.kernel.org/r/20220608154640.1235958-1-eric.dumazet@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

As explained in commit 316580b6 ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As explained in commit 316580b6 ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As explained in commit 316580b6 ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As explained in commit 316580b6 ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We have a convenient helper, let's use it.
This will make the following patch easier to review and smaller.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We have a convenient helper, let's use it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

We have a convenient helper, let's use it.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As explained in commit 316580b6 ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.

Add READ_ONCE() when reading rx_errs & tx_drps.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As explained in commit 316580b6 ("u64_stats: provide u64_stats_t type")
we should use u64_stats_t and related accessors to avoid load/store tearing.

Add READ_ONCE() when reading rx_errors & tx_dropped.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
 dev_hold_track()    -> netdev_hold()
 dev_put_track()     -> netdev_put()
 dev_replace_track() -> netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

No conflicts.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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

  Current release - regressions:

   - eth: amt: fix possible null-ptr-deref in amt_rcv()

  Previous releases - regressions:

   - tcp: use alloc_large_system_hash() to allocate table_perturb

   - af_unix: fix a data-race in unix_dgram_peer_wake_me()

   - nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling

   - eth: ixgbe: fix unexpected VLAN rx in promisc mode on VF

  Previous releases - always broken:

   - ipv6: fix signed integer overflow in __ip6_append_data

   - netfilter:
       - nat: really support inet nat without l3 address
       - nf_tables: memleak flow rule from commit path

   - bpf: fix calling global functions from BPF_PROG_TYPE_EXT programs

   - openvswitch: fix misuse of the cached connection on tuple changes

   - nfc: nfcmrvl: fix memory leak in nfcmrvl_play_deferred

   - eth: altera: fix refcount leak in altera_tse_mdio_create

  Misc:

   - add Quentin Monnet to bpftool maintainers"

* tag 'net-5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (45 commits)
  net: amd-xgbe: fix clang -Wformat warning
  tcp: use alloc_large_system_hash() to allocate table_perturb
  net: dsa: realtek: rtl8365mb: fix GMII caps for ports with internal PHY
  net: dsa: mv88e6xxx: correctly report serdes link failure
  net: dsa: mv88e6xxx: fix BMSR error to be consistent with others
  net: dsa: mv88e6xxx: use BMSR_ANEGCOMPLETE bit for filling an_complete
  net: altera: Fix refcount leak in altera_tse_mdio_create
  net: openvswitch: fix misuse of the cached connection on tuple changes
  net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag
  ip_gre: test csum_start instead of transport header
  au1000_eth: stop using virt_to_bus()
  ipv6: Fix signed integer overflow in l2tp_ip6_sendmsg
  ipv6: Fix signed integer overflow in __ip6_append_data
  nfc: nfcmrvl: Fix memory leak in nfcmrvl_play_deferred
  nfc: st21nfca: fix incorrect sizing calculations in EVT_TRANSACTION
  nfc: st21nfca: fix memory leaks in EVT_TRANSACTION handling
  nfc: st21nfca: fix incorrect validating logic in EVT_TRANSACTION
  net: ipv6: unexport __init-annotated seg6_hmac_init()
  net: xfrm: unexport __init-annotated xfrm4_protocol_init()
  net: mdio: unexport __init-annotated mdio_bus_init()
  ...

This is a pure band-aid so that I can continue merging stuff from people
while some of the gcc-12 fallout gets sorted out.

In particular, gcc-12 is very unhappy about the kinds of pointer
arithmetic tricks that netfs does, and that makes the fortify checks
trigger in afs and ceph:

  In function ‘fortify_memset_chk’,
      inlined from ‘netfs_i_context_init’ at include/linux/netfs.h:327:2,
      inlined from ‘afs_set_netfs_context’ at fs/afs/inode.c:61:2,
      inlined from ‘afs_root_iget’ at fs/afs/inode.c:543:2:
  include/linux/fortify-string.h:258:25: warning: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
    258 |                         __write_overflow_field(p_size_field, size);
        |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

and the reason is that netfs_i_context_init() is passed a 'struct inode'
pointer, and then it does

        struct netfs_i_context *ctx = netfs_i_context(inode);

        memset(ctx, 0, sizeof(*ctx));

where that netfs_i_context() function just does pointer arithmetic on
the inode pointer, knowing that the netfs_i_context is laid out
immediately after it in memory.

This is all truly disgusting, since the whole "netfs_i_context is laid
out immediately after it in memory" is not actually remotely true in
general, but is just made to be that way for afs and ceph.

See for example fs/cifs/cifsglob.h:

  struct cifsInodeInfo {
        struct {
                /* These must be contiguous */
                struct inode    vfs_inode;      /* the VFS's inode record */
                struct netfs_i_context netfs_ctx; /* Netfslib context */
        };
	[...]

and realize that this is all entirely wrong, and the pointer arithmetic
that netfs_i_context() is doing is also very very wrong and wouldn't
give the right answer if netfs_ctx had different alignment rules from a
'struct inode', for example).

Anyway, that's just a long-winded way to say "the gcc-12 warning is
actually quite reasonable, and our code happens to work but is pretty
disgusting".

This is getting fixed properly, but for now I made the mistake of
thinking "the week right after the merge window tends to be calm for me
as people take a breather" and I did a sustem upgrade.  And I got gcc-12
as a result, so to continue merging fixes from people and not have the
end result drown in warnings, I am fixing all these gcc-12 issues I hit.

Including with these kinds of temporary fixes.

Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/all/AEEBCF5D-8402-441D-940B-105AA718C71F@chromium.org/Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In commit 8b202ee2 ("s390: disable -Warray-bounds") the s390 people
disabled the '-Warray-bounds' warning for gcc-12, because the new logic
in gcc would cause warnings for their use of the S390_lowcore macro,
which accesses absolute pointers.

It turns out gcc-12 has many other issues in this area, so this takes
that s390 warning disable logic, and turns it into a kernel build config
entry instead.

Part of the intent is that we can make this all much more targeted, and
use this conflig flag to disable it in only particular configurations
that cause problems, with the s390 case as an example:

        select GCC12_NO_ARRAY_BOUNDS

and we could do that for other configuration cases that cause issues.

Or we could possibly use the CONFIG_CC_NO_ARRAY_BOUNDS thing in a more
targeted way, and disable the warning only for particular uses: again
the s390 case as an example:

  KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_CC_NO_ARRAY_BOUNDS),-Wno-array-bounds)

but this ends up just doing it globally in the top-level Makefile, since
the current issues are spread fairly widely all over:

  KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds

We'll try to limit this later, since the gcc-12 problems are rare enough
that *much* of the kernel can be built with it without disabling this
warning.

Cc: Kees Cook <keescook@chromium.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gcc-12 started warning about 'tracker' being used uninitialized:

  drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c: In function ‘mlx5_do_bond’:
  drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c:786:28: warning: ‘tracker’ is used uninitialized [-Wuninitialized]
    786 |         struct lag_tracker tracker;
        |                            ^~~~~~~

which seems to be because it doesn't track how the use (and
initialization) is bound by the 'do_bond' flag.

But admittedly that 'do_bond' usage is fairly complicated, and involves
passing it around as an argument to helper functions, so it's somewhat
understandable that gcc doesn't see how that all works.

This function could be rewritten to make the use of that tracker
variable more obviously safe, but for now I'm just adding the forced
initialization of it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

While the concept of checking for dangling pointers to local variables
at function exit is really interesting, the gcc-12 implementation is not
compatible with reality, and results in false positives.

For example, gcc sees us putting things on a local list head allocated
on the stack, which involves exactly those kinds of pointers to the
local stack entry:

  In function ‘__list_add’,
      inlined from ‘list_add_tail’ at include/linux/list.h:102:2,
      inlined from ‘rebuild_snap_realms’ at fs/ceph/snap.c:434:2:
  include/linux/list.h:74:19: warning: storing the address of local variable ‘realm_queue’ in ‘*&realm_27(D)->rebuild_item.prev’ [-Wdangling-pointer=]
     74 |         new->prev = prev;
        |         ~~~~~~~~~~^~~~~~

But then gcc - understandably - doesn't really understand the big
picture how the doubly linked list works, so doesn't see how we then end
up emptying said list head in a loop and the pointer we added has been
removed.

Gcc also complains about us (intentionally) using this as a way to store
a kind of fake stack trace, eg

  drivers/acpi/acpica/utdebug.c:40:38: warning: storing the address of local variable ‘current_sp’ in ‘acpi_gbl_entry_stack_pointer’ [-Wdangling-pointer=]
     40 |         acpi_gbl_entry_stack_pointer = &current_sp;
        |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~

which is entirely reasonable from a compiler standpoint, and we may want
to change those kinds of patterns, but not not.

So this is one of those "it would be lovely if the compiler were to
complain about us leaving dangling pointers to the stack", but not this
way.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Gcc-12 correctly warned about this code using a non-NULL pointer as a
truth value:

  drivers/gpu/drm/imx/ipuv3-crtc.c: In function ‘ipu_crtc_disable_planes’:
  drivers/gpu/drm/imx/ipuv3-crtc.c:72:21: error: the comparison will always evaluate as ‘true’ for the address of ‘plane’ will never be NULL [-Werror=address]
     72 |                 if (&ipu_crtc->plane[1] && plane == &ipu_crtc->plane[1]->base)
        |                     ^

due to the extraneous '&' address-of operator.

Philipp Zabel points out that The mistake had no adverse effect since
the following condition doesn't actually dereference the NULL pointer,
but the intent of the code was obviously to check for it, not to take
the address of the member.

Fixes: eb8c8880 ("drm/imx: add deferred plane disabling")
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gem_ptp_set_one_step_sync() always returns zero thus change its return
type to void.
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20220608080818.1495044-1-claudiu.beznea@microchip.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

Ronak Doshi says:

====================
vmxnet3: upgrade to version 7

vmxnet3 emulation has recently added several new features including
support for uniform passthrough(UPT). To make UPT work vmxnet3 has
to be enhanced as per the new specification. This patch series
extends the vmxnet3 driver to leverage these new features.

Compatibility is maintained using existing vmxnet3 versioning mechanism as
follows:
 - new features added to vmxnet3 emulation are associated with new vmxnet3
   version viz. vmxnet3 version 7.
 - emulation advertises all the versions it supports to the driver.
 - during initialization, vmxnet3 driver picks the highest version number
 supported by both the emulation and the driver and configures emulation
 to run at that version.

In particular, following changes are introduced:

Patch 1:
  This patch introduces utility macros for vmxnet3 version 7 comparison
  and updates Copyright information.

Patch 2:
  This patch adds new capability registers to fine control enablement of
  individual features based on emulation and passthrough.

Patch 3:
  This patch adds support for large passthrough BAR register.

Patch 4:
  This patch adds support for out of order rx completion processing.

Patch 5:
  This patch introduces new command to set ring buffer sizes to pass this
  information to the hardware.

Patch 6:
  For better performance, hardware has a requirement to limit number of TSO
  descriptors. This patch adds that support.

Patch 7:
  With vmxnet3 version 7, new descriptor fields are used to indicate
  encapsulation offload.

Patch 8:
  With all vmxnet3 version 7 changes incorporated in the vmxnet3 driver,
  with this patch, the driver can configure emulation to run at vmxnet3
  version 7.

Changes in v2->v3:
 - use correct byte ordering for ringBufSize

Changes in v2:
 - use local rss_fields variable for the rss capability checks in patch 2
====================

Link: https://lore.kernel.org/r/20220608032353.964-1-doshir@vmware.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

With all vmxnet3 version 7 changes incorporated in the vmxnet3 driver,
the driver can configure emulation to run at vmxnet3 version 7, provided
the emulation advertises support for version 7.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Till vmxnet3 version 6, om field of transmit descriptor was used
to indicate encapsulated offload packet and msscof was used to
indirectly indicate TSO/CSO. From version 7 and later, ext1 field
will be used to indicate whether packet is encapsulated or not and
om fields will continue to indicate if the packet is TSO or CSO.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Currently, vmxnet3 does not have a limit on number of descriptors
used for a TSO packet. However, with UPT, for hardware performance
reasons, this patch limits the number of transmit descriptors to 24
for a TSO packet.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This patch adds a new command to set ring buffer sizes. This is
required to pass the buffer size information to passthrough devices.
For performance reasons, with version7 and later, ring1 will contain
only mtu size buffers (bound to 3K). Packets > 3K will use both ring1
and ring2.

Also, ring sizes are round down to power of 2 and ring2 default
size is increased to 512.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Currently, vmxnet3 processes rx completions in-order i.e. no
out of order completion descriptor is expected. With UPT, if
hardware supports LRO, then hardware can report out of order
rx completions. This patch enhances vmxnet3 to add this support.
This supports gets effective only when the corresponding feature
bit is set.

Also, minor enhancements are done for performance.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

For vmxnet3 to work in UPT mode, the BAR sizes have been increased.
The PT page has been extended to 2 pages and also includes OOB pages
as a part of PT BAR. This patch enhances vmxnet3 to use appropriate
BAR offsets based on the capability registered. To use new offsets,
VMXNET3_CAP_LARGE_BAR needs to be set by the device. If it is not set
then the device will use legacy PT page layout.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This patch enhances vmxnet3 to suuport capability registers which
allows it to enable features selectively. The DCR register tracks
the capabilities vmxnet3 device supports. The PTCR register states
the capabilities that the passthrough device supports.

With the help of these registers, vmxnet3 can enable only those
features which the passthrough device supoprts. This allows
smooth trasition to Uniform-Passthrough (UPT) mode if the virtual
nic requests it. If PTCR register returns nothing or error it means
UPT is not being requested and vnic will continue in emulation mode.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

vmxnet3 is currently at version 6 and this patch initiates the
preparation to accommodate changes for upto version 7. Introduced
utility macros for vmxnet3 version 7 comparison and update Copyright
information.
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Guolin Yang <gyang@vmware.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

see warning:
| drivers/net/ethernet/amd/xgbe/xgbe-drv.c:2787:43: warning: format specifies
| type 'unsigned short' but the argument has type 'int' [-Wformat]
|        netdev_dbg(netdev, "Protocol: %#06hx\n", ntohs(eth->h_proto));
|                                      ~~~~~~     ^~~~~~~~~~~~~~~~~~~

Variadic functions (printf-like) undergo default argument promotion.
Documentation/core-api/printk-formats.rst specifically recommends
using the promoted-to-type's format flag.

Also, as per C11 6.3.1.1:
(https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1548.pdf)
`If an int can represent all values of the original type ..., the
value is converted to an int; otherwise, it is converted to an
unsigned int. These are called the integer promotions.`

Since the argument is a u16 it will get promoted to an int and thus it is
most accurate to use the %x format specifier here. It should be noted that the
`#06` formatting sugar does not alter the promotion rules.

Link: https://github.com/ClangBuiltLinux/linux/issues/378Signed-off-by: Justin Stitt <jstitt007@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20220607191119.20686-1-jstitt007@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

In our server, there may be no high order (>= 6) memory since we reserve
lots of HugeTLB pages when booting.  Then the system panic.  So use
alloc_large_system_hash() to allocate table_perturb.

Fixes: e9261476 ("tcp: dynamically allocate the perturb table used by source ports")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220607070214.94443-1-songmuchun@bytedance.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Remove some unused macros and functions, make local functions static.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20220608043726.9380-1-jgross@suse.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Since commit a18e6521 ("net: phylink: handle NA interface mode in
phylink_fwnode_phy_connect()"), phylib defaults to GMII when no phy-mode
or phy-connection-type property is specified in a DSA port node of the
device tree. The same commit caused a regression in rtl8365mb whereby
phylink would fail to connect, because the driver did not advertise
support for GMII for ports with internal PHY.

It should be noted that the aforementioned regression is not because the
blamed commit was incorrect: on the contrary, the blamed commit is
correcting the previous behaviour whereby unspecified phy-mode would
cause the internal interface mode to be PHY_INTERFACE_MODE_NA. The
rtl8365mb driver only worked by accident before because it _did_
advertise support for PHY_INTERFACE_MODE_NA, despite NA being reserved
for internal use by phylink. With one mistake fixed, the other was
exposed.

Commit a5dba0f2 ("net: dsa: rtl8365mb: add GMII as user port mode")
then introduced implicit support for GMII mode on ports with internal
PHY to allow a PHY connection for device trees where the phy-mode is not
explicitly set to "internal". At this point everything was working OK
again.

Subsequently, commit 6ff60646 ("net: dsa: realtek: convert to
phylink_generic_validate()") broke this behaviour again by discarding
the usage of rtl8365mb_phy_mode_supported() - where this GMII support
was indicated - while switching to the new .phylink_get_caps API.

With the new API, rtl8365mb_phy_mode_supported() is no longer needed.
Remove it altogether and add back the GMII capability - this time to
rtl8365mb_phylink_get_caps() - so that the above default behaviour works
for ports with internal PHY again.

Fixes: 6ff60646 ("net: dsa: realtek: convert to phylink_generic_validate()")
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/20220607184624.417641-1-alvin@pqrs.dkSigned-off-by: Jakub Kicinski <kuba@kernel.org>