A freshly allocated skb starts with timestamps clear.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The SFC9100 family has only one clock per controller, shared by all
functions.  Therefore only create a clock device under the primary
function, and make all other functions refer to the primary's clock
device.

Since PTP functionality is limited to port 0 and PF 0 on the earlier
SFN[56]322F boards, and we also set the primary flag for that
function, we can make the creation of a clock device conditional only
on this flag.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The primary function of an EF10 controller will share its clock
device with other functions in the same domain (which we call
secondary functions).  To this end, we need to associate functions
on the same controller.

We do not control probe order, so allow primary and secondary
functions to appear in any order.  Maintain global lists of all
primary functions and of unassociated secondary functions,
and a list of secondary functions on each primary function.

Use the VPD serial number to tell whether functions are part of the
same controller.  VPD will not be readable by virtual functions, so
this may need to be revisited later.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Original version by Stuart Hodgson.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The EF10 firmware can optionally insert RX timestamps in the packet
prefix.  These only include the clock minor value.  We must also
enable periodic time sync events on each event queue which provide
the high bits of the clock value.

[bwh: Combined and rebased several changes.
 Added the above description and some sanity checks for inline vs
 separate timestamps.
 Changed efx_rx_skb_attach_timestamp() to read the packet prefix
 from the skb head area.]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We can potentially pull the entire packet contents into the head area
and then free the page it was in.  In order to read an inline
timestamp safely, we need to copy the prefix into the head area as
well.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

I added efx_ptp_get_mode() to avoid moving the definition for
efx_ptp_data, since the current PTP mode is needed for
siena.c:siena_set_ptp_hwtstamp.

[bwh: Also move the rx_filters mask, and add kernel-doc]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The clock minor tick on the SFC9100 family is 2^-27 s, not 1 ns.
There are also various pipeline delays which we need to correct for
when interpreting timestamps.

We query the firmware for the clock format and corrections at run-time.

[bwh: Combined and rebased several changes]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We'll be sharing clocks between multiple functions with their own MAC
addresses.  The name field is now documented as 'A short "friendly
name" to identify the clock ...' and '... not meant to be a unique
id.'  So use the name 'sfc'.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We need a dedicated channel on Siena to ensure we can match up
the separate RX and timestamp events for each PTP packet.  We won't
do this for EF10 as timestamps are delivered inline.

Pass a channel index of 0 to MC_CMD_PTP_OP_ENABLE when there is no
dedicated channel.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The MC firmware will return error MC_CMD_ERR_ENOSPC if filter
insertion fails due to lack of resources.  The net driver's filter
implementation for Falcon-architecture returns EBUSY.  They should
behave consistently, so for EF10 change ENOSPC to EBUSY.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

efx_flush_all() is a really misleading name - it has nothing to do
with e.g. flushing DMA queues.  Since it's called immediately after
efx_stop_port() and is highly dependent on what that does, combine
the two functions.

Update comments to explain what this is doing a little better.
Also update an related and erroneous comment in efx_start_port().
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Split each of efx_mcdi_rpc, efx_mcdi_rpc_finish, and efx_mcdi_rpc_async into
a normal and a _quiet version; made the former log MCDI errors with
netif_err (and include the raw MCDI error code), and the latter never log
them at all.  Changed various callers; any where some errors are expected
(but others are not) call the _quiet version and then if necessary log the
MCDI error themselves.  Said logging is done by new efx_mcdi_display_error.

Callers of efx_mcdi_rpc*_quiet functions which may want to log the error
need to ensure that their outbuf is big enough to hold an MCDI error; to
this end, they now use MCDI_DECLARE_BUF_OUT_OR_ERR, which always allocates
at least 8 bytes.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Add units to the "Sensor reports condition X for raw value Y" messages.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

We don't directly control RX ingress on Siena or any later
controllers, and so we cannot prevent packets from entering the RX
datapath while the RX queues are not set up.  This results in
the hardware incrementing RX_NODESC_DROP_CNT, but it's not an
error and we should not include it in error stats.

When bringing an interface up or down, pull (or wait for) stats and
count the number of packets that were dropped while the interface was
down.  Subtract this from the reported RX dropped count.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The addition of RX event merging support means we don't reliably
detect dropped RX events now.  Currently we will only detect them if
the previous event for the RX queue had the CONT bit set.

Only accept RX completion events as merged if the
GET_CAPABILITIES_OUT_RX_BATCHING bit is set in datapath_caps (which it
won't be for the low-latency datapath) and the CONT bit is not set on
the event.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

To run BISTs the MC goes down in to a special mode where it will only
respond to MCDI from the testing PF, and TX, RX and event queues are
torn down. Other PFs get a message as it goes down to tell them it's
going down.

When the other PFs get this message, they check the soft status
register to tell when the MC has rebooted after BIST mode and they can
start recovery.

[bwh: Convert the test result to 1 or -1 as for earlier NICs]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

The MC firmware is cooperatively multitasking and its scheduler will
send an event when a task yields after running for more than the
expected maximum time.  This can be useful for firmware development
but does not usually indicate a serious error and does not help to
detect a lockup (there is a hardware watchdog that does that).
Change the message and reduce log level accordingly.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Merge sfc fixes destined for 3.13, as development for 3.14+ depends on
some of them.

There is an as-yet unexplained bug that sometimes prevents (or delays)
the driver seeing the completion event for a completed MCDI request on
the SFC9120.  The requested configuration change will have happened
but the driver assumes it to have failed, and this can result in
further failures.  We can mitigate this by polling for completion
after unsuccessfully waiting for an event.

Fixes: 8127d661 ('sfc: Add support for Solarflare SFC9100 family')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

rx_prefix_size is 4-bytes aligned on Falcon/Siena (16 bytes), but it is equal
to 14 on EF10. So, it should be taken into account if arch requires IP header
to be 4-bytes aligned (via NET_IP_ALIGN).

Fixes: 8127d661 ('sfc: Add support for Solarflare SFC9100 family')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

There is a single MCDI PTP operation for setting the frequency
adjustment and applying a time offset to the hardware clock.  When
applying a time offset we should not change the frequency adjustment.

These two operations can now be requested separately but this requires
a flash firmware update.  Keep using the single operation, but
remember and repeat the previous frequency adjustment.

Fixes: 7c236c43 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

This disables PTP when we bring the interface down to avoid getting
unmatched RX timestamp events, and tries to re-enable it when bringing
the interface up.

[bwh: Make efx_ptp_stop() safe on Falcon. Introduce
 efx_ptp_{start,stop}_datapath() functions; we'll expand them later.]

Fixes: 7c236c43 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

In case of a flood of PTP packets, the timestamp peripheral and MC
firmware on the SFN[56]322F boards may not be able to provide
timestamp events for all packets.  Don't complain too much about this.

Fixes: 7c236c43 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

Limit syslog flood if a PTP packet storm occurs.

Fixes: 7c236c43 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

efx_ptp_is_ptp_tx() must be robust against skbs from raw sockets that
have invalid IPv4 and UDP headers.

Add checks that:
- the transport header has been found
- there is enough space between network and transport header offset
  for an IPv4 header
- there is enough space after the transport header offset for a
  UDP header

Fixes: 7c236c43 ('sfc: Add support for IEEE-1588 PTP')
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

With the introduction of TCP Small Queues, TSO auto sizing, and TCP
pacing, we can implement Automatic Corking in the kernel, to help
applications doing small write()/sendmsg() to TCP sockets.

Idea is to change tcp_push() to check if the current skb payload is
under skb optimal size (a multiple of MSS bytes)

If under 'size_goal', and at least one packet is still in Qdisc or
NIC TX queues, set the TCP Small Queue Throttled bit, so that the push
will be delayed up to TX completion time.

This delay might allow the application to coalesce more bytes
in the skb in following write()/sendmsg()/sendfile() system calls.

The exact duration of the delay is depending on the dynamics
of the system, and might be zero if no packet for this flow
is actually held in Qdisc or NIC TX ring.

Using FQ/pacing is a way to increase the probability of
autocorking being triggered.

Add a new sysctl (/proc/sys/net/ipv4/tcp_autocorking) to control
this feature and default it to 1 (enabled)

Add a new SNMP counter : nstat -a | grep TcpExtTCPAutoCorking
This counter is incremented every time we detected skb was under used
and its flush was deferred.

Tested:

Interesting effects when using line buffered commands under ssh.

Excellent performance results in term of cpu usage and total throughput.

lpq83:~# echo 1 >/proc/sys/net/ipv4/tcp_autocorking
lpq83:~# perf stat ./super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128
9410.39

 Performance counter stats for './super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128':

      35209.439626 task-clock                #    2.901 CPUs utilized
             2,294 context-switches          #    0.065 K/sec
               101 CPU-migrations            #    0.003 K/sec
             4,079 page-faults               #    0.116 K/sec
    97,923,241,298 cycles                    #    2.781 GHz                     [83.31%]
    51,832,908,236 stalled-cycles-frontend   #   52.93% frontend cycles idle    [83.30%]
    25,697,986,603 stalled-cycles-backend    #   26.24% backend  cycles idle    [66.70%]
   102,225,978,536 instructions              #    1.04  insns per cycle
                                             #    0.51  stalled cycles per insn [83.38%]
    18,657,696,819 branches                  #  529.906 M/sec                   [83.29%]
        91,679,646 branch-misses             #    0.49% of all branches         [83.40%]

      12.136204899 seconds time elapsed

lpq83:~# echo 0 >/proc/sys/net/ipv4/tcp_autocorking
lpq83:~# perf stat ./super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128
6624.89

 Performance counter stats for './super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128':
      40045.864494 task-clock                #    3.301 CPUs utilized
               171 context-switches          #    0.004 K/sec
                53 CPU-migrations            #    0.001 K/sec
             4,080 page-faults               #    0.102 K/sec
   111,340,458,645 cycles                    #    2.780 GHz                     [83.34%]
    61,778,039,277 stalled-cycles-frontend   #   55.49% frontend cycles idle    [83.31%]
    29,295,522,759 stalled-cycles-backend    #   26.31% backend  cycles idle    [66.67%]
   108,654,349,355 instructions              #    0.98  insns per cycle
                                             #    0.57  stalled cycles per insn [83.34%]
    19,552,170,748 branches                  #  488.244 M/sec                   [83.34%]
       157,875,417 branch-misses             #    0.81% of all branches         [83.34%]

      12.130267788 seconds time elapsed
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>