History log of /linux-master/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.h
Revision Date Author Comments
# 9a1ac95a 16-Jun-2021 Aharon Landau <aharonl@nvidia.com>

RDMA/mlx5: Refactor get_ts_format functions to simplify code

QPC, SQC and RQC timestamp formats and capabilities are always equal
because they represent general hardware support. So instead of code
duplication, let's merge them into general enum and logic.

Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>


# 183532b7 02-Mar-2021 Aya Levin <ayal@nvidia.com>

net/mlx5: Add helper to set time-stamp translator on a queue

Translation method on the time-stamp is set by the capabilities. Avoid
code duplication by using a helper to set ptp_cyc2time callback on a
queue.

Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>


# 432119de 12-Feb-2021 Aya Levin <ayal@nvidia.com>

net/mlx5: Add cyc2time HW translation mode support

Device timestamp can be in real time mode (cycles to time translation is
offloaded into the Hardware). With real time mode, HW provides timestamp
which is already translated into nanoseconds.

With this mode, driver adjusts both the HW and timecounter (to keep
clock_info_page updated) using callbacks: adjfreq, adjtime and settime.
HW clock modifications are done via MTUTC access reg commands. Driver is
allowed to modify HW real time clock only if MCAM ptpcyc2realtime_modify
capability is set.

Add MTUTC set function to be used for configuring the HW real time
clock. Modify existing code to support both internal timer (with
conversion via timecounter_cyc2time() and real time (no conversions).

Align the signatures of the helpers converting from timestamp to
nanoseconds. With that, when allocating a queue assign the corresponding
callback with respect to the capability.

Adjust 1PPS timestamp calculation flows based on the timestamp mode.

Cyc2time offload brings two major advantages:
- Improve MTAE (Max Time Absolute Error) for HW TS by up to 160 ns over a
100% loaded CPU.
- Faster data-path timestamp to nanoseconds, as translation is
lock-less and done in HW.

On real time mode, timestamp format is 32 high bits of seconds and 32
low bits of nanoseconds. On some flows, driver shall convert this format
into nanoseconds wall-clock with REAL_TIME_TO_NS macro.

HW supports a single clock, and it is shared by all functions on a
device. In case real time clock is used, it is recommended to use
a single GM to all device's functions.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Aya Levin <ayal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>


# d6f3dc8f 12-Feb-2021 Eran Ben Elisha <eranbe@mellanox.com>

net/mlx5: Move all internal timer metadata into a dedicated struct

Internal timer mode (SW clock) requires some PTP clock related metadata
structs. Real time mode (HW clock) will not need these metadata structs.
This separation emphasize the different interfaces for HW clock and SW
clock.

Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Aya Levin <ayal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>


# 41069256 20-Nov-2018 Saeed Mahameed <saeedm@mellanox.com>

net/mlx5: Clock, Use async events chain

Remove the explicit call to mlx5_pps_event on MLX5_EVENT_TYPE_PPS_EVENT
and let clock logic to register its own handler when its ready.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>


# 64109f1d 05-Jun-2018 Shay Agroskin <shayag@mellanox.com>

net/mlx5e: Replace PTP clock lock from RW lock to seq lock

Changed "priv.clock.lock" lock from 'rw_lock' to 'seq_lock'
in order to improve packet rate performance.

Tested on Intel(R) Xeon(R) CPU E5-2660 v2 @ 2.20GHz.
Sent 64b packets between two peers connected by ConnectX-5,
and measured packet rate for the receiver in three modes:
no time-stamping (base rate)
time-stamping using rw_lock (old lock) for critical region
time-stamping using seq_lock (new lock) for critical region
Only the receiver time stamped its packets.

The measured packet rate improvements are:

Single flow (multiple TX rings to single RX ring):
without timestamping: 4.26 (M packets)/sec
with rw-lock (old lock): 4.1 (M packets)/sec
with seq-lock (new lock): 4.16 (M packets)/sec
1.46% improvement

Multiple flows (multiple TX rings to six RX rings):
without timestamping: 22 (M packets)/sec
with rw-lock (old lock): 11.7 (M packets)/sec
with seq-lock (new lock): 21.3 (M packets)/sec
82.05% improvement

The packet rate improvement is due to the lack of atomic operations
for the 'readers' by the seq-lock.
Since there are much more 'readers' than 'writers' contention
on this lock, almost all atomic operations are saved.
this results in a dramatic decrease in overall
cache misses.

Signed-off-by: Shay Agroskin <shayag@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>


# 6dbc80ca 29-Jul-2018 Moshe Shemesh <moshe@mellanox.com>

net/mlx5e: clock.c depends on CONFIG_PTP_1588_CLOCK

lib/clock.c includes clock related functions which require ptp support.
Thus compile out lib/clock.c and add the needed function stubs in case
kconfig CONFIG_PTP_1588_CLOCK is off.

Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>


# 7c39afb3 15-Aug-2017 Feras Daoud <ferasda@mellanox.com>

net/mlx5: PTP code migration to driver core section

PTP code is moved to core section of mlx5 driver in order to share
it between ethernet and infiniband. This movement involves the following
changes:
- Change mlx5e_ prefix to be mlx5_
- Add clock structs to Core
- Add clock object to mlx5_core_dev
- Call Init/Uninit clock from core init/cleanup
- Rename mlx5e_tstamp to be mlx5_clock

Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Eitan Rabin <rabin@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>