saner replacement for debugfs_rename()

Existing primitive has several problems:
1) calling conventions are clumsy - it returns a dentry reference
that is either identical to its second argument or

saner replacement for debugfs_rename()

Existing primitive has several problems:
1) calling conventions are clumsy - it returns a dentry reference
that is either identical to its second argument or is an ERR_PTR(-E...);
in both cases no refcount changes happen. Inconvenient for users and
bug-prone; it would be better to have it return 0 on success and -E... on
failure.
2) it allows cross-directory moves; however, no such caller have
ever materialized and considering the way debugfs is used, it's unlikely
to happen in the future. What's more, any such caller would have fun
issues to deal with wrt interplay with recursive removal. It also makes
the calling conventions clumsier...
3) tautological rename fails; the callers have no race-free way
to deal with that.
4) new name must have been formed by the caller; quite a few
callers have it done by sprintf/kasprintf/etc., ending up with considerable
boilerplate.

Proposed replacement: int debugfs_change_name(dentry, fmt, ...). All callers
convert to that easily, and it's simpler internally.

IMO debugfs_rename() should go; if we ever get a real-world use case for
cross-directory moves in debugfs, we can always look into the right way
to handle that.

Signed-off-by: Al Viro <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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wifi: mac80211: prohibit deactivating all links

In the internal API this calls this is a WARN_ON, but that
should remain since internally we want to know about bugs
that may cause this. Prevent deac

wifi: mac80211: prohibit deactivating all links

In the internal API this calls this is a WARN_ON, but that
should remain since internally we want to know about bugs
that may cause this. Prevent deactivating all links in the
debugfs write directly.

Reported-by: [email protected]
Fixes: 3d9011029227 ("wifi: mac80211: implement link switching")
Signed-off-by: Johannes Berg <[email protected]>
Link: https://patch.msgid.link/20241230091408.505bd125c35a.Ic3c1f9572b980a952a444cad62b09b9c6721732b@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: convert debugfs files to short fops

Given the large size of the regular struct file_operations, save
a lot of space with the newly added short fops for debugfs.

Link: https://patch.

wifi: mac80211: convert debugfs files to short fops

Given the large size of the regular struct file_operations, save
a lot of space with the newly added short fops for debugfs.

Link: https://patch.msgid.link/20241022151838.2f6de3ea3ecc.I45657e6a8415d796ec95c95becc9efb377ee3be6@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: fix driver debugfs for vif type change

If a driver implements the change_interface() method, we switch
interface type without taking the interface down, but still will
recreate the d

wifi: mac80211: fix driver debugfs for vif type change

If a driver implements the change_interface() method, we switch
interface type without taking the interface down, but still will
recreate the debugfs for it since it's a new type. As such, we
should use the ieee80211_debugfs_recreate_netdev() function here
to also recreate the driver's files, if it is indeed from a type
change while up.

Link: https://msgid.link/20240129155402.7311a36ffeeb.I18df02bbeb685d4250911de5ffbaf090f60c3803@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: add/remove driver debugfs entries as appropriate

When an interface is removed, we should also be deleting the driver
debugfs entries (as it might still exist in DOWN state in mac8021

wifi: mac80211: add/remove driver debugfs entries as appropriate

When an interface is removed, we should also be deleting the driver
debugfs entries (as it might still exist in DOWN state in mac80211). At
the same time, when adding an interface, we can check the
IEEE80211_SDATA_IN_DRIVER flag to know whether the interface was
previously known to the driver and is simply being reconfigured.

Fixes: a1f5dcb1c0c1 ("wifi: mac80211: add a driver callback to add vif debugfs")
Signed-off-by: Benjamin Berg <[email protected]>
Reviewed-by: Gregory Greenman <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://msgid.link/20231220043149.a9f64c359424.I7076526b5297ae8f832228079c999f7b8e147a4c@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: use wiphy locked debugfs for sdata/link

The debugfs files for netdevs (sdata) and links are removed
with the wiphy mutex held, which may deadlock. Use the new
wiphy locked debugfs to

wifi: mac80211: use wiphy locked debugfs for sdata/link

The debugfs files for netdevs (sdata) and links are removed
with the wiphy mutex held, which may deadlock. Use the new
wiphy locked debugfs to avoid that.

Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: Rename and update IEEE80211_VIF_DISABLE_SMPS_OVERRIDE

EMLSR operation and SMPS operation cannot coexist. Thus, when EMLSR is
enabled, all SMPS signaling towards the AP should be stop

wifi: mac80211: Rename and update IEEE80211_VIF_DISABLE_SMPS_OVERRIDE

EMLSR operation and SMPS operation cannot coexist. Thus, when EMLSR is
enabled, all SMPS signaling towards the AP should be stopped (it is
expected that the AP will consider SMPS to be off).

Rename IEEE80211_VIF_DISABLE_SMPS_OVERRIDE to IEEE80211_VIF_EML_ACTIVE
and use the flag as an indication from the driver that EMLSR is enabled.
When EMLSR is enabled SMPS flows towards the AP MLD should be stopped.

Signed-off-by: Ilan Peer <[email protected]>
Signed-off-by: Gregory Greenman <[email protected]>
Link: https://lore.kernel.org/r/20230928172905.fb2c2f9a0645.If6df5357568abd623a081f0f33b07e63fb8bba99@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: handle debugfs when switching to/from MLO

In MLO, we have a per-link debugfs directory which contains the
per-link files. In case of non-MLO we would like to put the per-link
files i

wifi: mac80211: handle debugfs when switching to/from MLO

In MLO, we have a per-link debugfs directory which contains the
per-link files. In case of non-MLO we would like to put the per-link
files in the netdev directory to keep it how it was before MLO.

- Upon interface creation the netdev will be created with the per-link
files in it.
- Upon switching to MLO: delete the entire netdev directory and then
recreate it without the per-link files. Then the per-link directories
with the per-link files in it will be created in ieee80211_link_init()
- Upon switching to non-MLO: delete the entire netdev directory
(including the per-link directories) and recreate it with the per-link
files in it.

Note that this also aligns to always call the vif link debugfs
method for the deflink as promised in the documentation, which
wasn't done before.

Signed-off-by: Miri Korenblit <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Gregory Greenman <[email protected]>
Link: https://lore.kernel.org/r/20230928172905.082e698caca9.I5bef7b2026e0f58b4a958b3d1f459ac5baeccfc9@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: cfg80211: remove wdev mutex

Since we're now protecting everything with the wiphy mutex
(and were really using it for almost everything before),
there's no longer any real reason to have a sepa

wifi: cfg80211: remove wdev mutex

Since we're now protecting everything with the wiphy mutex
(and were really using it for almost everything before),
there's no longer any real reason to have a separate wdev
mutex. It may feel better, but really has no value.

Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: hold wiphy lock in netdev/link debugfs

It's no longer really needed to ensure that the debugfs
file isn't going away, debugfs handles that. So there's
no point in holding dev_base_lo

wifi: mac80211: hold wiphy lock in netdev/link debugfs

It's no longer really needed to ensure that the debugfs
file isn't going away, debugfs handles that. So there's
no point in holding dev_base_lock or RTNL here, but we
should instead hold the wiphy lock since drivers will
be allowed to depend on that. Do that, which requires
splitting the sdata and link macros a bit.

Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: Add debugfs entry to report dormant links

Add debugfs entry to report dormant (valid but disabled) links.

Signed-off-by: Ilan Peer <[email protected]>
Signed-off-by: Gregory Green

wifi: mac80211: Add debugfs entry to report dormant links

Add debugfs entry to report dormant (valid but disabled) links.

Signed-off-by: Ilan Peer <[email protected]>
Signed-off-by: Gregory Greenman <[email protected]>
Link: https://lore.kernel.org/r/20230611121219.7fa5f022adfb.Iff6fa3e1a3b00ae726612f9d5a31f7fe2fcbfc68@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: Fix permissions for valid_links debugfs entry

The entry should be a read only one and not a write only one. Fix it.

Fixes: 3d9011029227 ("wifi: mac80211: implement link switching")

wifi: mac80211: Fix permissions for valid_links debugfs entry

The entry should be a read only one and not a write only one. Fix it.

Fixes: 3d9011029227 ("wifi: mac80211: implement link switching")
Signed-off-by: Ilan Peer <[email protected]>
Signed-off-by: Gregory Greenman <[email protected]>
Link: https://lore.kernel.org/r/20230611121219.c75316990411.I1565a7fcba8a37f83efffb0cc6b71c572b896e94@changeid
[remove x16 change since it doesn't work yet]
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: allow disabling SMPS debugfs controls

There are cases in which we don't want the user to override the
smps mode, e.g. when SMPS should be disabled due to EMLSR. Add
a driver flag to

wifi: mac80211: allow disabling SMPS debugfs controls

There are cases in which we don't want the user to override the
smps mode, e.g. when SMPS should be disabled due to EMLSR. Add
a driver flag to disable SMPS overriding and don't override if
it is set.

Signed-off-by: Miri Korenblit <[email protected]>
Signed-off-by: Gregory Greenman <[email protected]>
Link: https://lore.kernel.org/r/20230608163202.ef129e80556c.I74a298fdc86b87074c95228d3916739de1400597@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: add netdev per-link debugfs data and driver hook

This adds the infrastructure to have netdev specific per-link data both
for mac80211 and the driver in debugfs. For the driver, a new

wifi: mac80211: add netdev per-link debugfs data and driver hook

This adds the infrastructure to have netdev specific per-link data both
for mac80211 and the driver in debugfs. For the driver, a new callback
is added which is only used if MLO is supported.

Signed-off-by: Benjamin Berg <[email protected]>
Signed-off-by: Gregory Greenman <[email protected]>
Link: https://lore.kernel.org/r/20230301115906.fb4c947e4df8.I69b3516ddf4c8a7501b395f652d6063444ecad63@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: remove SMPS from AP debugfs

The spatial multiplexing power save feature does not apply to
AP mode. Remove it from debugfs in this case.

Signed-off-by: Benjamin Berg <benjamin.berg@i

wifi: mac80211: remove SMPS from AP debugfs

The spatial multiplexing power save feature does not apply to
AP mode. Remove it from debugfs in this case.

Signed-off-by: Benjamin Berg <[email protected]>
Signed-off-by: Gregory Greenman <[email protected]>
Link: https://lore.kernel.org/r/20230301115906.01b167027dd5.Iee69f2e4df98581f259ef2c76309b940b20174be@changeid
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: remove mesh forwarding congestion check

Now that all drivers use iTXQ, it does not make sense to check to drop
tx forwarding packets when the driver has stopped the queues.
fq_codel

wifi: mac80211: remove mesh forwarding congestion check

Now that all drivers use iTXQ, it does not make sense to check to drop
tx forwarding packets when the driver has stopped the queues.
fq_codel will take care of dropping packets when the queues fill up

Signed-off-by: Felix Fietkau <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: Drop support for TX push path

All drivers are now using mac80211 internal queues (iTXQs).
Drop mac80211 internal support for the old push path.

Signed-off-by: Alexander Wetzel <alex

wifi: mac80211: Drop support for TX push path

All drivers are now using mac80211 internal queues (iTXQs).
Drop mac80211 internal support for the old push path.

Signed-off-by: Alexander Wetzel <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: implement link switching

Implement an API function and debugfs file to switch
active links.

Also provide an async version of the API so drivers
can call it in arbitrary contexts, e.

wifi: mac80211: implement link switching

Implement an API function and debugfs file to switch
active links.

Also provide an async version of the API so drivers
can call it in arbitrary contexts, e.g. while in the
authorized callback.

Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: RCU-ify link/link_conf pointers

Since links can be added and removed dynamically, we need to
somehow protect the sdata->link[] and vif->link_conf[] array
pointers from disappearing w

wifi: mac80211: RCU-ify link/link_conf pointers

Since links can be added and removed dynamically, we need to
somehow protect the sdata->link[] and vif->link_conf[] array
pointers from disappearing when accessing them without locks.
RCU-ify the pointers to achieve this, which requires quite a
bit of rework.

Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: switch airtime fairness back to deficit round-robin scheduling

This reverts commits 6a789ba679d652587532cec2a0e0274fda172f3b and
2433647bc8d983a543e7d31b41ca2de1c7e2c198.

The virtua

wifi: mac80211: switch airtime fairness back to deficit round-robin scheduling

This reverts commits 6a789ba679d652587532cec2a0e0274fda172f3b and
2433647bc8d983a543e7d31b41ca2de1c7e2c198.

The virtual time scheduler code has a number of issues:
- queues slowed down by hardware/firmware powersave handling were not properly
handled.
- on ath10k in push-pull mode, tx queues that the driver tries to pull from
were starved, causing excessive latency
- delay between tx enqueue and reported airtime use were causing excessively
bursty tx behavior

The bursty behavior may also be present on the round-robin scheduler, but there
it is much easier to fix without introducing additional regressions

Signed-off-by: Felix Fietkau <[email protected]>
Acked-by: Toke Høiland-Jørgensen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: make some SMPS code MLD-aware

Start making some SMPS related code MLD-aware. This isn't
really done yet, but again cuts down our 'deflink' reliance.

Signed-off-by: Johannes Berg <jo

wifi: mac80211: make some SMPS code MLD-aware

Start making some SMPS related code MLD-aware. This isn't
really done yet, but again cuts down our 'deflink' reliance.

Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: reorg some iface data structs for MLD

Start reorganizing interface related data structures toward
MLD. The most complex part here is for the keys, since we
have to split the various

wifi: mac80211: reorg some iface data structs for MLD

Start reorganizing interface related data structures toward
MLD. The most complex part here is for the keys, since we
have to split the various kinds of GTKs off to the link but
still need to use (for WEP) the other keys as a fallback
even for multicast frames.

Signed-off-by: Johannes Berg <[email protected]>

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wifi: mac80211: move interface config to new struct

We'll use bss_conf for per-link configuration later, so
move out all the non-link-specific data out into a new
struct ieee80211_vif_cfg used in th

wifi: mac80211: move interface config to new struct

We'll use bss_conf for per-link configuration later, so
move out all the non-link-specific data out into a new
struct ieee80211_vif_cfg used in the vif.

Some adjustments were done with the following spatch:

@@
expression sdata;
struct ieee80211_vif *vifp;
identifier var = { assoc, ibss_joined, aid, arp_addr_list, arp_addr_cnt, ssid, ssid_len, s1g, ibss_creator };
@@
(
-sdata->vif.bss_conf.var
+sdata->vif.cfg.var
|
-vifp->bss_conf.var
+vifp->cfg.var
)

@bss_conf@
struct ieee80211_bss_conf *bss_conf;
identifier var = { assoc, ibss_joined, aid, arp_addr_list, arp_addr_cnt, ssid, ssid_len, s1g, ibss_creator };
@@
-bss_conf->var
+vif_cfg->var

(though more manual fixups were needed, e.g. replacing
"vif_cfg->" by "vif->cfg." in many files.)

Signed-off-by: Johannes Berg <[email protected]>

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mac80211: use ifmgd->bssid instead of ifmgd->associated->bssid

Since we always track the BSSID there when we get associated,
these are equivalent, but ifmgd->bssid saves a dereference and
thus makes

mac80211: use ifmgd->bssid instead of ifmgd->associated->bssid

Since we always track the BSSID there when we get associated,
these are equivalent, but ifmgd->bssid saves a dereference and
thus makes the code a bit smaller, and more readable.

Signed-off-by: Johannes Berg <[email protected]>

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mac80211: remove unused macros

Various macros in mac80211 aren't used, remove them. In one
case it's used under ifdef, so ifdef it for the W=2 warning.

Signed-off-by: Johannes Berg <johannes.berg@i

mac80211: remove unused macros

Various macros in mac80211 aren't used, remove them. In one
case it's used under ifdef, so ifdef it for the W=2 warning.

Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Luca Coelho <[email protected]>
Link: https://lore.kernel.org/r/iwlwifi.20220202104617.5172d7fd878e.I2f1fce686a2b71003f083b2566fb09cf16b8165a@changeid
Signed-off-by: Johannes Berg <[email protected]>

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