dpll: add Embedded SYNC feature for a pin

Implement and document new pin attributes for providing Embedded SYNC
capabilities to the DPLL subsystem users through a netlink pin-get
do/dump messages. A

dpll: add Embedded SYNC feature for a pin

Implement and document new pin attributes for providing Embedded SYNC
capabilities to the DPLL subsystem users through a netlink pin-get
do/dump messages. Allow the user to set Embedded SYNC frequency with
pin-set do netlink message.

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20240822222513.255179-2-arkadiusz.kubalewski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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doc: netlink: Don't 'sanitize' op docstrings in generated .rst

The doc strings for do/dump ops are emitted as toplevel .rst constructs
so they can be multi-line. Pass multi-line text straight throug

doc: netlink: Don't 'sanitize' op docstrings in generated .rst

The doc strings for do/dump ops are emitted as toplevel .rst constructs
so they can be multi-line. Pass multi-line text straight through to the
.rst to retain any simple formatting from the .yaml

This fixes e.g. list formatting for the pin-get docs in dpll.yaml:

https://docs.kernel.org/6.9/networking/netlink_spec/dpll.html#pin-get

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240528140652.9445-3-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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dpll: spec: use proper enum for pin capabilities attribute

The enum is defined, however the pin capabilities attribute does
refer to it. Add this missing enum field.

This fixes ynl cli output:

Exa

dpll: spec: use proper enum for pin capabilities attribute

The enum is defined, however the pin capabilities attribute does
refer to it. Add this missing enum field.

This fixes ynl cli output:

Example current output:
$ sudo ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/dpll.yaml --do pin-get --json '{"id": 0}'
{'capabilities': 4,
...
Example new output:
$ sudo ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/dpll.yaml --do pin-get --json '{"id": 0}'
{'capabilities': {'state-can-change'},
...

Fixes: 3badff3a25d8 ("dpll: spec: Add Netlink spec in YAML")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20240306120739.1447621-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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dpll: fix possible deadlock during netlink dump operation

Recently, I've been hitting following deadlock warning during dpll pin
dump:

[52804.637962] ===============================================

dpll: fix possible deadlock during netlink dump operation

Recently, I've been hitting following deadlock warning during dpll pin
dump:

[52804.637962] ======================================================
[52804.638536] WARNING: possible circular locking dependency detected
[52804.639111] 6.8.0-rc2jiri+ #1 Not tainted
[52804.639529] ------------------------------------------------------
[52804.640104] python3/2984 is trying to acquire lock:
[52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xb3/0x780
[52804.641417]
but task is already holding lock:
[52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, at: dpll_lock_dumpit+0x13/0x20
[52804.642747]
which lock already depends on the new lock.

[52804.643551]
the existing dependency chain (in reverse order) is:
[52804.644259]
-> #1 (dpll_lock){+.+.}-{3:3}:
[52804.644836] lock_acquire+0x174/0x3e0
[52804.645271] __mutex_lock+0x119/0x1150
[52804.645723] dpll_lock_dumpit+0x13/0x20
[52804.646169] genl_start+0x266/0x320
[52804.646578] __netlink_dump_start+0x321/0x450
[52804.647056] genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.647575] genl_rcv_msg+0x1ed/0x3b0
[52804.648001] netlink_rcv_skb+0xdc/0x210
[52804.648440] genl_rcv+0x24/0x40
[52804.648831] netlink_unicast+0x2f1/0x490
[52804.649290] netlink_sendmsg+0x36d/0x660
[52804.649742] __sock_sendmsg+0x73/0xc0
[52804.650165] __sys_sendto+0x184/0x210
[52804.650597] __x64_sys_sendto+0x72/0x80
[52804.651045] do_syscall_64+0x6f/0x140
[52804.651474] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.652001]
-> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}:
[52804.652650] check_prev_add+0x1ae/0x1280
[52804.653107] __lock_acquire+0x1ed3/0x29a0
[52804.653559] lock_acquire+0x174/0x3e0
[52804.653984] __mutex_lock+0x119/0x1150
[52804.654423] netlink_dump+0xb3/0x780
[52804.654845] __netlink_dump_start+0x389/0x450
[52804.655321] genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.655842] genl_rcv_msg+0x1ed/0x3b0
[52804.656272] netlink_rcv_skb+0xdc/0x210
[52804.656721] genl_rcv+0x24/0x40
[52804.657119] netlink_unicast+0x2f1/0x490
[52804.657570] netlink_sendmsg+0x36d/0x660
[52804.658022] __sock_sendmsg+0x73/0xc0
[52804.658450] __sys_sendto+0x184/0x210
[52804.658877] __x64_sys_sendto+0x72/0x80
[52804.659322] do_syscall_64+0x6f/0x140
[52804.659752] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.660281]
other info that might help us debug this:

[52804.661077] Possible unsafe locking scenario:

[52804.661671] CPU0 CPU1
[52804.662129] ---- ----
[52804.662577] lock(dpll_lock);
[52804.662924] lock(nlk_cb_mutex-GENERIC);
[52804.663538] lock(dpll_lock);
[52804.664073] lock(nlk_cb_mutex-GENERIC);
[52804.664490]

The issue as follows: __netlink_dump_start() calls control->start(cb)
with nlk->cb_mutex held. In control->start(cb) the dpll_lock is taken.
Then nlk->cb_mutex is released and taken again in netlink_dump(), while
dpll_lock still being held. That leads to ABBA deadlock when another
CPU races with the same operation.

Fix this by moving dpll_lock taking into dumpit() callback which ensures
correct lock taking order.

Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Link: https://lore.kernel.org/r/20240207115902.371649-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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dpll: extend uapi by lock status error attribute

If the dpll devices goes to state "unlocked" or "holdover", it may be
caused by an error. In that case, allow user to see what the error was.
Introdu

dpll: extend uapi by lock status error attribute

If the dpll devices goes to state "unlocked" or "holdover", it may be
caused by an error. In that case, allow user to see what the error was.
Introduce a new attribute and values it can carry.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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dpll: expose fractional frequency offset value to user

Add a new netlink attribute to expose fractional frequency offset value
for a pin. Add an op to get the value from the driver.

Signed-off-by:

dpll: expose fractional frequency offset value to user

Add a new netlink attribute to expose fractional frequency offset value
for a pin. Add an op to get the value from the driver.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Acked-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Acked-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Link: https://lore.kernel.org/r/20240103132838.1501801-2-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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dpll: spec: add support for pin-dpll signal phase offset/adjust

Add attributes for providing the user with:
- measurement of signals phase offset between pin and dpll
- ability to adjust the phase o

dpll: spec: add support for pin-dpll signal phase offset/adjust

Add attributes for providing the user with:
- measurement of signals phase offset between pin and dpll
- ability to adjust the phase of pin signal

Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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netlink: specs: remove redundant type keys from attributes in subsets

No longer needed to define type for subset attributes. Remove those.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: J

netlink: specs: remove redundant type keys from attributes in subsets

No longer needed to define type for subset attributes. Remove those.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231006114436.1725425-3-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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dpll: spec: Add Netlink spec in YAML

Add a protocol spec for DPLL.
Add code generated from the spec.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Michal Michalik <michal.michalik@

dpll: spec: Add Netlink spec in YAML

Add a protocol spec for DPLL.
Add code generated from the spec.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Michal Michalik <michal.michalik@intel.com>
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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