This qdisc offload is the closest thing to what the SJA1105 supports in
hardware for time-based egress shaping. The switch core really is built
around SAE AS6802/TTEthernet (a TTTech standard) but can be made to
operate similarly to IEEE 802.1Qbv with some constraints:
- The gate control list is a global list for all ports. There are 8
execution threads that iterate through this global list in parallel.
I don't know why 8, there are only 4 front-panel ports.
- Care must be taken by the user to make sure that two execution threads
never get to execute a GCL entry simultaneously. I created a O(n^4)
checker for this hardware limitation, prior to accepting a taprio
offload configuration as valid.
- The spec says that if a GCL entry's interval is shorter than the frame
length, you shouldn't send it (and end up in head-of-line blocking).
Well, this switch does anyway.
- The switch has no concept of ADMIN and OPER configurations. Because
it's so simple, the TAS settings are loaded through the static config
tables interface, so there isn't even place for any discussion about
'graceful switchover between ADMIN and OPER'. You just reset the
switch and upload a new OPER config.
- The switch accepts multiple time sources for the gate events. Right
now I am using the standalone clock source as opposed to PTP. So the
base time parameter doesn't really do much. Support for the PTP clock
source will be added in a future series.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As Arnd Bergmann pointed out in commit 78fe8a28fb ("net: dsa: sja1105:
fix ptp link error"), there is no point in having PTP support as a
separate loadable kernel module.
So remove the exported symbols and make sja1105.ko contain PTP support
or not based on CONFIG_NET_DSA_SJA1105_PTP.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Due to a reversed dependency, it is possible to build
the lower ptp driver as a loadable module and the actual
driver using it as built-in, causing a link error:
drivers/net/dsa/sja1105/sja1105_spi.o: In function `sja1105_static_config_upload':
sja1105_spi.c:(.text+0x6f0): undefined reference to `sja1105_ptp_reset'
drivers/net/dsa/sja1105/sja1105_spi.o:(.data+0x2d4): undefined reference to `sja1105et_ptp_cmd'
drivers/net/dsa/sja1105/sja1105_spi.o:(.data+0x604): undefined reference to `sja1105pqrs_ptp_cmd'
drivers/net/dsa/sja1105/sja1105_main.o: In function `sja1105_remove':
sja1105_main.c:(.text+0x8d4): undefined reference to `sja1105_ptp_clock_unregister'
drivers/net/dsa/sja1105/sja1105_main.o: In function `sja1105_rxtstamp_work':
sja1105_main.c:(.text+0x964): undefined reference to `sja1105_tstamp_reconstruct'
drivers/net/dsa/sja1105/sja1105_main.o: In function `sja1105_setup':
sja1105_main.c:(.text+0xb7c): undefined reference to `sja1105_ptp_clock_register'
drivers/net/dsa/sja1105/sja1105_main.o: In function `sja1105_port_deferred_xmit':
sja1105_main.c:(.text+0x1fa0): undefined reference to `sja1105_ptpegr_ts_poll'
sja1105_main.c:(.text+0x1fc4): undefined reference to `sja1105_tstamp_reconstruct'
drivers/net/dsa/sja1105/sja1105_main.o:(.rodata+0x5b0): undefined reference to `sja1105_get_ts_info'
Change the Makefile logic to always build the ptp module
the same way as the rest. Another option would be to
just add it to the same module and remove the exports,
but I don't know if there was a good reason to keep them
separate.
Fixes: bb77f36ac2 ("net: dsa: sja1105: Add support for the PTP clock")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The design of this PHC driver is influenced by the switch's behavior
w.r.t. timestamping. It exposes two PTP counters, one free-running
(PTPTSCLK) and the other offset- and frequency-corrected in hardware
through PTPCLKVAL, PTPCLKADD and PTPCLKRATE. The MACs can sample either
of these for frame timestamps.
However, the user manual warns that taking timestamps based on the
corrected clock is less than useful, as the switch can deliver corrupted
timestamps in a variety of circumstances.
Therefore, this PHC uses the free-running PTPTSCLK together with a
timecounter/cyclecounter structure that translates it into a software
time domain. Thus, the settime/adjtime and adjfine callbacks are
hardware no-ops.
The timestamps (introduced in a further patch) will also be translated
to the correct time domain before being handed over to the userspace PTP
stack.
The introduction of a second set of PHC operations that operate on the
hardware PTPCLKVAL/PTPCLKADD/PTPCLKRATE in the future is somewhat
unavoidable, as the TTEthernet core uses the corrected PTP time domain.
However, the free-running counter + timecounter structure combination
will suffice for now, as the resulting timestamps yield a sub-50 ns
synchronization offset in steady state using linuxptp.
For this patch, in absence of frame timestamping, the operations of the
switch PHC were tested by syncing it to the system time as a local slave
clock with:
phc2sys -s CLOCK_REALTIME -c swp2 -O 0 -m -S 0.01
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add SPDX license identifiers to all Make/Kconfig files which:
- Have no license information of any form
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At this moment the following is supported:
* Link state management through phylib
* Autonomous L2 forwarding managed through iproute2 bridge commands.
IP termination must be done currently through the master netdevice,
since the switch is unmanaged at this point and using
DSA_TAG_PROTO_NONE.
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Georg Waibel <georg.waibel@sensor-technik.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
