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[net-next,v4,00/11] ptp: support virtual clocks and timestamping

Message ID 20210625093513.38524-1-yangbo.lu@nxp.com
Headers show
Series ptp: support virtual clocks and timestamping | expand

Message

Y.b. Lu June 25, 2021, 9:35 a.m. UTC
Current PTP driver exposes one PTP device to user which binds network
interface/interfaces to provide timestamping. Actually we have a way
utilizing timecounter/cyclecounter to virtualize any number of PTP
clocks based on a same free running physical clock for using.
The purpose of having multiple PTP virtual clocks is for user space
to directly/easily use them for multiple domains synchronization.

user
space:     ^                                  ^
           | SO_TIMESTAMPING new flag:        | Packets with
           | SOF_TIMESTAMPING_BIND_PHC        | TX/RX HW timestamps
           v                                  v
         +--------------------------------------------+
sock:    |     sock (new member sk_bind_phc)          |
         +--------------------------------------------+
           ^                                  ^
           | ethtool_get_phc_vclocks          | Convert HW timestamps
           |                                  | to sk_bind_phc
           v                                  v
         +--------------+--------------+--------------+
vclock:  | ptp1         | ptp2         | ptpN         |
         +--------------+--------------+--------------+
pclock:  |             ptp0 free running              |
         +--------------------------------------------+

The block diagram may explain how it works. Besides the PTP virtual
clocks, the packet HW timestamp converting to the bound PHC is also
done in sock driver. For user space, PTP virtual clocks can be
created via sysfs, and extended SO_TIMESTAMPING API (new flag
SOF_TIMESTAMPING_BIND_PHC) can be used to bind one PTP virtual clock
for timestamping.

The test tool timestamping.c (together with linuxptp phc_ctl tool) can
be used to verify:

  # echo 4 > /sys/class/ptp/ptp0/n_vclocks
  [  129.399472] ptp ptp0: new virtual clock ptp2
  [  129.404234] ptp ptp0: new virtual clock ptp3
  [  129.409532] ptp ptp0: new virtual clock ptp4
  [  129.413942] ptp ptp0: new virtual clock ptp5
  [  129.418257] ptp ptp0: guarantee physical clock free running
  #
  # phc_ctl /dev/ptp2 set 10000
  # phc_ctl /dev/ptp3 set 20000
  #
  # timestamping eno0 2 SOF_TIMESTAMPING_TX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC
  # timestamping eno0 2 SOF_TIMESTAMPING_RX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC
  # timestamping eno0 3 SOF_TIMESTAMPING_TX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC
  # timestamping eno0 3 SOF_TIMESTAMPING_RX_HARDWARE SOF_TIMESTAMPING_RAW_HARDWARE SOF_TIMESTAMPING_BIND_PHC

Changes for v2:
	- Converted to num_vclocks for creating virtual clocks.
	- Guranteed physical clock free running when using virtual
	  clocks.
	- Fixed build warning.
	- Updated copyright.
Changes for v3:
	- Supported PTP virtual clock in default in PTP driver.
	- Protected concurrency of ptp->num_vclocks accessing.
	- Supported PHC vclocks query via ethtool.
	- Extended SO_TIMESTAMPING API for PHC binding.
	- Converted HW timestamps to PHC bound, instead of previous
	  binding domain value to PHC idea.
	- Other minor fixes.
Changes for v4:
	- Used do_aux_work callback for vclock refreshing instead.
	- Used unsigned int for vclocks number, and max_vclocks
	  for limitiation.
	- Fixed mutex locking.
	- Dynamically allocated memory for vclock index storage.
	- Removed ethtool ioctl command for vclocks getting.
	- Updated doc for ethtool phc vclocks get.
	- Converted to mptcp_setsockopt_sol_socket_timestamping().
	- Passed so_timestamping for sock_set_timestamping.
	- Fixed checkpatch/build.
	- Other minor fixed.

Yangbo Lu (11):
  ptp: add ptp virtual clock driver framework
  ptp: support ptp physical/virtual clocks conversion
  ptp: track available ptp vclocks information
  ptp: add kernel API ptp_get_vclocks_index()
  ethtool: add a new command for getting PHC virtual clocks
  ptp: add kernel API ptp_convert_timestamp()
  mptcp: setsockopt: convert to
    mptcp_setsockopt_sol_socket_timestamping()
  net: sock: extend SO_TIMESTAMPING for PHC binding
  net: socket: support hardware timestamp conversion to PHC bound
  selftests/net: timestamping: support binding PHC
  MAINTAINERS: add entry for PTP virtual clock driver

 Documentation/ABI/testing/sysfs-ptp          |  20 ++
 Documentation/networking/ethtool-netlink.rst |  22 ++
 MAINTAINERS                                  |   7 +
 drivers/ptp/Makefile                         |   2 +-
 drivers/ptp/ptp_clock.c                      |  41 +++-
 drivers/ptp/ptp_private.h                    |  39 ++++
 drivers/ptp/ptp_sysfs.c                      | 160 ++++++++++++++
 drivers/ptp/ptp_vclock.c                     | 219 +++++++++++++++++++
 include/linux/ethtool.h                      |  10 +
 include/linux/ptp_clock_kernel.h             |  31 ++-
 include/net/sock.h                           |   8 +-
 include/uapi/linux/ethtool_netlink.h         |  15 ++
 include/uapi/linux/net_tstamp.h              |  17 +-
 net/core/sock.c                              |  65 +++++-
 net/ethtool/Makefile                         |   2 +-
 net/ethtool/common.c                         |  14 ++
 net/ethtool/netlink.c                        |  10 +
 net/ethtool/netlink.h                        |   2 +
 net/ethtool/phc_vclocks.c                    |  94 ++++++++
 net/mptcp/sockopt.c                          |  69 ++++--
 net/socket.c                                 |  19 +-
 tools/testing/selftests/net/timestamping.c   |  62 ++++--
 22 files changed, 875 insertions(+), 53 deletions(-)
 create mode 100644 drivers/ptp/ptp_vclock.c
 create mode 100644 net/ethtool/phc_vclocks.c


base-commit: 19938bafa7ae8fc0a4a2c1c1430abb1a04668da1

Comments

Michal Kubecek Aug. 29, 2021, 5:04 p.m. UTC | #1
On Fri, Jun 25, 2021 at 05:35:07PM +0800, Yangbo Lu wrote:
> Add an interface for getting PHC (PTP Hardware Clock)

> virtual clocks, which are based on PHC physical clock

> providing hardware timestamp to network packets.

> 

> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>


Hello,

do you plan to submit also an ethtool (userspace utility) patch using
this interface?

Michal

> ---

> Changes for v3:

> 	- Added this patch.

> Changes for v4:

> 	- Updated doc.

> 	- Removed ioctl command.

> 	- Replied only the number of vclock index.

> ---

>  Documentation/networking/ethtool-netlink.rst | 22 +++++

>  include/linux/ethtool.h                      | 10 +++

>  include/uapi/linux/ethtool_netlink.h         | 15 ++++

>  net/ethtool/Makefile                         |  2 +-

>  net/ethtool/common.c                         | 13 +++

>  net/ethtool/netlink.c                        | 10 +++

>  net/ethtool/netlink.h                        |  2 +

>  net/ethtool/phc_vclocks.c                    | 94 ++++++++++++++++++++

>  8 files changed, 167 insertions(+), 1 deletion(-)

>  create mode 100644 net/ethtool/phc_vclocks.c

> 

> diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst

> index 6ea91e41593f..c86628e6a235 100644

> --- a/Documentation/networking/ethtool-netlink.rst

> +++ b/Documentation/networking/ethtool-netlink.rst

> @@ -212,6 +212,7 @@ Userspace to kernel:

>    ``ETHTOOL_MSG_FEC_SET``               set FEC settings

>    ``ETHTOOL_MSG_MODULE_EEPROM_GET``     read SFP module EEPROM

>    ``ETHTOOL_MSG_STATS_GET``             get standard statistics

> +  ``ETHTOOL_MSG_PHC_VCLOCKS_GET``       get PHC virtual clocks info

>    ===================================== ================================

>  

>  Kernel to userspace:

> @@ -250,6 +251,7 @@ Kernel to userspace:

>    ``ETHTOOL_MSG_FEC_NTF``                  FEC settings

>    ``ETHTOOL_MSG_MODULE_EEPROM_GET_REPLY``  read SFP module EEPROM

>    ``ETHTOOL_MSG_STATS_GET_REPLY``          standard statistics

> +  ``ETHTOOL_MSG_PHC_VCLOCKS_GET_REPLY``    PHC virtual clocks info

>    ======================================== =================================

>  

>  ``GET`` requests are sent by userspace applications to retrieve device

> @@ -1477,6 +1479,25 @@ Low and high bounds are inclusive, for example:

>   etherStatsPkts512to1023Octets 512  1023

>   ============================= ==== ====

>  

> +PHC_VCLOCKS_GET

> +===============

> +

> +Query device PHC virtual clocks information.

> +

> +Request contents:

> +

> +  ====================================  ======  ==========================

> +  ``ETHTOOL_A_PHC_VCLOCKS_HEADER``      nested  request header

> +  ====================================  ======  ==========================

> +

> +Kernel response contents:

> +

> +  ====================================  ======  ==========================

> +  ``ETHTOOL_A_PHC_VCLOCKS_HEADER``      nested  reply header

> +  ``ETHTOOL_A_PHC_VCLOCKS_NUM``         u32     PHC virtual clocks number

> +  ``ETHTOOL_A_PHC_VCLOCKS_INDEX``       s32     PHC index array

> +  ====================================  ======  ==========================

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