[net-next,v2,0/9] ptp: convert drivers to .adjfine

Message

Jacob Keller Sept. 30, 2022, 8:48 p.m. UTC

Many drivers implementing PTP have not yet migrated to the new .adjfine
frequency adjustment implementation.

A handful of these drivers use hardware with a simple increment value which
is adjusted by multiplying by the adjustment factor and then dividing by
1 billion. This calculation is very easy to convert to .adjfine, by simply
updating the divisor.

Introduce new helper functions, diff_by_scaled_ppm and adjust_by_scaled_ppm
which perform the most common calculations used by drivers for this purpose.

The adjust_by_scaled_ppm takes the base increment and scaled PPM value, and
calculates the new increment to use.

A few drivers need the difference and direction rather than a raw increment
value. The diff_by_scaled_ppm calculates the difference and returns true if
it should be a subtraction, false otherwise. This most closely aligns with
existing driver implementations.

I previously submitted v1 of this series at [1], and got some feedback only
on a handful of drivers. In the interest of merging the changes which have
received feedback, I've dropped the following drivers out of this send:

 * ptp_phc
 * ptp_ipx46x
 * tg3
 * hclge
 * stmac
 * cpts

I plan to submit those drivers changes again at a later date. As before,
there are some drivers which are not trivial to convert to the new helper
functions. While they may be able to work, their implementation is different
and I lack the hardware or datasheets to determine what the correct
implementation would be.


* drivers/net/ethernet/broadcom/bnx2x
* drivers/net/ethernet/broadcom/bnxt
* drivers/net/ethernet/cavium/liquidio
* drivers/net/ethernet/chelsio/cxgb4
* drivers/net/ethernet/freescale
* drivers/net/ethernet/qlogic/qed
* drivers/net/ethernet/qlogic/qede
* drivers/net/ethernet/sfc
* drivers/net/ethernet/sfc/siena
* drivers/net/ethernet/ti/am65-cpts.c
* drivers/ptp/ptp_dte.c

My end goal is to drop the .adjfreq implementation entirely, and to that end
I plan on modifying these drivers in the future to directly use
scaled_ppm_to_ppb as the simplest method to convert them.

Cc: "K. Y. Srinivasan" <[e-mail]>
Cc: Haiyang Zhang <[e-mail]>
Cc: Stephen Hemminger <[e-mail]>
Cc: Wei Liu <[e-mail]>
Cc: Dexuan Cui <[e-mail]>
Cc: Tom Lendacky <[e-mail]>
Cc: Shyam Sundar S K <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Eric Dumazet <[e-mail]>
Cc: Jakub Kicinski <[e-mail]>
Cc: Paolo Abeni <[e-mail]>
Cc: Siva Reddy Kallam <[e-mail]>
Cc: Prashant Sreedharan <[e-mail]>
Cc: Michael Chan <[e-mail]>
Cc: Yisen Zhuang <[e-mail]>
Cc: Salil Mehta <[e-mail]>
Cc: Jesse Brandeburg <[e-mail]>
Cc: Tony Nguyen <[e-mail]>
Cc: Tariq Toukan <[e-mail]>
Cc: Saeed Mahameed <[e-mail]>
Cc: Leon Romanovsky <[e-mail]>
Cc: Bryan Whitehead <[e-mail]>
Cc: Sergey Shtylyov <[e-mail]>
Cc: Giuseppe Cavallaro <[e-mail]>
Cc: Alexandre Torgue <[e-mail]>
Cc: Jose Abreu <[e-mail]>
Cc: Maxime Coquelin <[e-mail]>
Cc: Richard Cochran <[e-mail]>
Cc: Vivek Thampi <[e-mail]>
Cc: VMware PV-Drivers Reviewers <[e-mail]>
Cc: Jie Wang <[e-mail]>
Cc: Jacob Keller <[e-mail]>
Cc: Guangbin Huang <[e-mail]>
Cc: Eran Ben Elisha <[e-mail]>
Cc: Aya Levin <[e-mail]>
Cc: Cai Huoqing <[e-mail]>
Cc: Biju Das <[e-mail]>
Cc: Lad Prabhakar <[e-mail]>
Cc: Phil Edworthy <[e-mail]>
Cc: Jiasheng Jiang <[e-mail]>
Cc: "Gustavo A. R. Silva" <[e-mail]>
Cc: Linus Walleij <[e-mail]>
Cc: Wan Jiabing <[e-mail]>
Cc: Lv Ruyi <[e-mail]>
Cc: Arnd Bergmann <[e-mail]>

Jacob Keller (9):
  ptp: add missing documentation for parameters
  ptp: introduce helpers to adjust by scaled parts per million
  drivers: convert unsupported .adjfreq to .adjfine
  ptp: mlx4: convert to .adjfine and adjust_by_scaled_ppm
  ptp: mlx5: convert to .adjfine and adjust_by_scaled_ppm
  ptp: lan743x: remove .adjfreq implementation
  ptp: lan743x: use diff_by_scaled_ppm in .adjfine implementation
  ptp: ravb: convert to .adjfine and adjust_by_scaled_ppm
  ptp: xgbe: convert to .adjfine and adjust_by_scaled_ppm

 drivers/hv/hv_util.c                          |  4 +-
 drivers/net/ethernet/amd/xgbe/xgbe-ptp.c      | 20 ++-----
 drivers/net/ethernet/intel/e1000e/ptp.c       | 16 ++----
 drivers/net/ethernet/intel/i40e/i40e_ptp.c    | 17 ++----
 drivers/net/ethernet/intel/ice/ice_ptp.c      | 18 +------
 drivers/net/ethernet/intel/igb/igb_ptp.c      | 18 +------
 drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c  | 24 ++-------
 drivers/net/ethernet/mellanox/mlx4/en_clock.c | 29 ++++------
 .../ethernet/mellanox/mlx5/core/lib/clock.c   | 22 +++-----
 drivers/net/ethernet/microchip/lan743x_ptp.c  | 54 +++----------------
 drivers/net/ethernet/renesas/ravb_ptp.c       | 17 ++----
 drivers/ptp/ptp_kvm_common.c                  |  4 +-
 drivers/ptp/ptp_vmw.c                         |  4 +-
 include/linux/ptp_clock_kernel.h              | 53 ++++++++++++++++++
 14 files changed, 105 insertions(+), 195 deletions(-)


base-commit: 915b96c52763e2988e6368b538b487a7138b8fa4

Comments

Jakub Kicinski Oct. 3, 2022, 4:54 p.m. UTC | #1

On Fri, 30 Sep 2022 13:48:42 -0700 Jacob Keller wrote:
> Many drivers implementing PTP have not yet migrated to the new .adjfine
> frequency adjustment implementation.

On a scale of 1 to 10 - how much do you care about this being in v6.1?

Richard Cochran Oct. 3, 2022, 5:37 p.m. UTC | #2

On Fri, Sep 30, 2022 at 01:48:42PM -0700, Jacob Keller wrote:
> Many drivers implementing PTP have not yet migrated to the new .adjfine
> frequency adjustment implementation.
> 
> A handful of these drivers use hardware with a simple increment value which
> is adjusted by multiplying by the adjustment factor and then dividing by
> 1 billion. This calculation is very easy to convert to .adjfine, by simply
> updating the divisor.
> 
> Introduce new helper functions, diff_by_scaled_ppm and adjust_by_scaled_ppm
> which perform the most common calculations used by drivers for this purpose.

For the series:

Acked-by: Richard Cochran <[e-mail]>

Jacob Keller Oct. 3, 2022, 6:04 p.m. UTC | #3

> -----Original Message-----
> From: Jakub Kicinski <[e-mail]>
> Sent: Monday, October 03, 2022 9:55 AM
> To: Keller, Jacob E <[e-mail]>
> Cc: [e-mail]; K. Y. Srinivasan <[e-mail]>; Haiyang
> Zhang <[e-mail]>; Stephen Hemminger
> <[e-mail]>; Wei Liu <[e-mail]>; Cui, Dexuan
> <[e-mail]>; Tom Lendacky <[e-mail]>; Shyam
> Sundar S K <[e-mail]>; David S. Miller
> <[e-mail]>; Eric Dumazet <[e-mail]>; Paolo Abeni
> <[e-mail]>; Siva Reddy Kallam <[e-mail]>;
> Prashant Sreedharan <[e-mail]>; Michael Chan
> <[e-mail]>; Yisen Zhuang <[e-mail]>; Salil
> Mehta <[e-mail]>; Brandeburg, Jesse
> <[e-mail]>; Nguyen, Anthony L
> <[e-mail]>; Tariq Toukan <[e-mail]>; Saeed
> Mahameed <[e-mail]>; Leon Romanovsky <[e-mail]>;
> Bryan Whitehead <[e-mail]>; Sergey Shtylyov
> <[e-mail]>; Giuseppe Cavallaro <[e-mail]>;
> Alexandre Torgue <[e-mail]>; Jose Abreu
> <[e-mail]>; Maxime Coquelin <[e-mail]>;
> Richard Cochran <[e-mail]>; Thampi, Vivek
> <[e-mail]>; VMware PV-Drivers Reviewers <pv-
> [e-mail]>; Jie Wang <[e-mail]>; Guangbin Huang
> <[e-mail]>; Eran Ben Elisha <[e-mail]>; Aya
> Levin <[e-mail]>; Cai Huoqing <[e-mail]>; Biju Das
> <[e-mail]>; Lad Prabhakar <prabhakar.mahadev-
> [e-mail]>; Phil Edworthy <[e-mail]>; Jiasheng
> Jiang <[e-mail]>; Gustavo A. R. Silva <[e-mail]>; Linus
> Walleij <[e-mail]>; Wan Jiabing <[e-mail]>; Lv Ruyi
> <[e-mail]>; Arnd Bergmann <[e-mail]>
> Subject: Re: [net-next v2 0/9] ptp: convert drivers to .adjfine
> 
> On Fri, 30 Sep 2022 13:48:42 -0700 Jacob Keller wrote:
> > Many drivers implementing PTP have not yet migrated to the new .adjfine
> > frequency adjustment implementation.
> 
> On a scale of 1 to 10 - how much do you care about this being in v6.1?

Eh, this can probably wait till after 6.1 merge closes and we can queue it into 6.2 instead. That would give everyone a bit longer for catching any issues and more time to include fixes that won't need to be ported back to net.

I guess I'd say like a 2 or 3 then.