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Use Device Serial Number instead of PCI bus/device/function for
the index of struct ice_adapter.
Functions on the same physical device should point to the very same
ice_adapter instance, but with two PFs, when at least one of them is
PCI-e passed-through to a VM, it is no longer the case - PFs will get
seemingly random PCI BDF values, and thus indices, what finally leds to
each of them being on their own instance of ice_adapter. That causes them
to don't attempt any synchronization of the PTP HW clock usage, or any
other future resources.
DSN works nicely in place of the index, as it is "immutable" in terms of
virtualization.
Fixes: 0e2bddf9e5f9 ("ice: add ice_adapter for shared data across PFs on the same NIC")
Suggested-by: Jacob Keller <jacob.e.keller@intel.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Suggested-by: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20250505161939.2083581-1-anthony.l.nguyen@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Use struct ice_adapter to hold shared PTP data and control PTP
related actions instead of auxbus. This allows significant code
simplification and faster access to the container fields used in
the PTP support code.
Move the PTP port list to the ice_adapter container to simplify
the code and avoid race conditions which could occur due to the
synchronous nature of the initialization/access and
certain memory saving can be achieved by moving PTP data into
the ice_adapter itself.
Signed-off-by: Sergey Temerkhanov <sergey.temerkhanov@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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Add ice_get_ctrl_ptp() wrapper to simplify the PTP support code
in the functions that do not use ctrl_pf directly.
Add the control PF pointer to struct ice_adapter
Rearrange fields in struct ice_adapter
Signed-off-by: Sergey Temerkhanov <sergey.temerkhanov@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The PTP hardware semaphore (PFTSYN_SEM) is used to synchronize
operations that program the PTP timers. The operations involve issuing
commands to the sideband queue. The E810 does not have a hardware
sideband queue, so the admin queue is used. The admin queue is slow.
I have observed delays in hundreds of milliseconds waiting for
ice_sq_done.
When phc2sys reads the time from the ice PTP clock and PFTSYN_SEM is
held by a task performing one of the slow operations, ice_ptp_lock can
easily time out. phc2sys gets -EBUSY and the kernel prints:
ice 0000:XX:YY.0: PTP failed to get time
These messages appear once every few seconds, causing log spam.
The E810 datasheet recommends an algorithm for reading the upper 64 bits
of the GLTSYN_TIME register. It matches what's implemented in
ice_ptp_read_src_clk_reg. It is robust against wrap-around, but not
necessarily against the concurrent setting of the register (with
GLTSYN_CMD_{INIT,ADJ}_TIME commands). Perhaps that's why
ice_ptp_gettimex64 also takes PFTSYN_SEM.
The race with time setters can be prevented without relying on the PTP
hardware semaphore. Using the "ice_adapter" from the previous patch,
we can have a common spinlock for the PFs that share the clock hardware.
It will protect the reading and writing to the GLTSYN_TIME register.
The writing is performed indirectly, by the hardware, as a result of
the driver writing GLTSYN_CMD_SYNC in ice_ptp_exec_tmr_cmd. I wasn't
sure if the ice_flush there is enough to make sure GLTSYN_TIME has been
updated, but it works well in my testing.
My test code can be seen here:
https://gitlab.com/mschmidt2/linux/-/commits/ice-ptp-host-side-lock-10
It consists of:
- kernel threads reading the time in a busy loop and looking at the
deltas between consecutive values, reporting new maxima.
- a shell script that sets the time repeatedly;
- a bpftrace probe to produce a histogram of the measured deltas.
Without the spinlock ptp_gltsyn_time_lock, it is easy to see tearing.
Deltas in the [2G, 4G) range appear in the histograms.
With the spinlock added, there is no tearing and the biggest delta I saw
was in the range [1M, 2M), that is under 2 ms.
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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There is a need for synchronization between ice PFs on the same physical
adapter.
Add a "struct ice_adapter" for holding data shared between PFs of the
same multifunction PCI device. The struct is refcounted - each ice_pf
holds a reference to it.
Its first use will be for PTP. I expect it will be useful also to
improve the ugliness that is ice_prot_id_tbl.
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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