igc: Fix hicredit calculation

According to the Intel Software Manual for I225, Section 7.5.2.7,
hicredit should be multiplied by the constant link-rate value, 0x7736.

Currently, the old constant link-rate value, 0x7735, from the boards
supported on igb are being used, most likely due to a copy'n'paste, as
the rest of the logic is the same for both drivers.

Update hicredit accordingly.

Fixes: 1ab011b0bf07 ("igc: Add support for CBS offloading")
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Rodrigo Cataldo <rodrigo.cadore@l-acoustics.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: No strict mode in pure launchtime/CBS offload

The flags IGC_TXQCTL_STRICT_CYCLE and IGC_TXQCTL_STRICT_END
prevent the packet transmission over slot and cycle boundaries.
This is important for taprio offload where the slots and
cycles correspond to the slots and cycles configured for the
network.

However, the Qbv offload feature of the i225 is also used for
enabling TX launchtime / ETF offload. In that case, however,
the cycle has no meaning for the network and is only used
internally to adapt the base time register after a second has
passed.

Enabling strict mode in this case would unnecessarily prevent
the transmission of certain packets (i.e. at the boundary of a
second) and thus interferes with the ETF qdisc that promises
transmission at a certain point in time.

Similar to ETF, this also applies to CBS offload that also should
not be influenced by strict mode unless taprio offload would be
enabled at the same time.

This fully reverts
commit d8f45be01dd9 ("igc: Use strict cycles for Qbv scheduling")
but its commit message only describes what was already implemented
before that commit. The difference to a plain revert of that commit
is that it now copes with the base_time = 0 case that was fixed with
commit e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")

In particular, enabling strict mode leads to TX hang situations
under high traffic if taprio is applied WITHOUT taprio offload
but WITH ETF offload, e.g. as in

sudo tc qdisc replace dev enp1s0 parent root handle 100 taprio \
num_tc 1 \
map 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 \
queues 1@0 \
base-time 0 \
sched-entry S 01 300000 \
flags 0x1 \
txtime-delay 500000 \
clockid CLOCK_TAI
sudo tc qdisc replace dev enp1s0 parent 100:1 etf \
clockid CLOCK_TAI \
delta 500000 \
offload \
skip_sock_check

and traffic generator

sudo trafgen -i traffic.cfg -o enp1s0 --cpp -n0 -q -t1400ns

with traffic.cfg

#define ETH_P_IP 0x0800

{
/* Ethernet Header */
0x30, 0x1f, 0x9a, 0xd0, 0xf0, 0x0e, # MAC Dest - adapt as needed
0x24, 0x5e, 0xbe, 0x57, 0x2e, 0x36, # MAC Src - adapt as needed
const16(ETH_P_IP),

/* IPv4 Header */
0b01000101, 0, # IPv4 version, IHL, TOS
const16(1028), # IPv4 total length (UDP length + 20 bytes (IP header))
const16(2), # IPv4 ident
0b01000000, 0, # IPv4 flags, fragmentation off
64, # IPv4 TTL
17, # Protocol UDP
csumip(14, 33), # IPv4 checksum

/* UDP Header */
10, 0, 48, 1, # IP Src - adapt as needed
10, 0, 48, 10, # IP Dest - adapt as needed
const16(5555), # UDP Src Port
const16(6666), # UDP Dest Port
const16(1008), # UDP length (UDP header 8 bytes + payload length)
csumudp(14, 34), # UDP checksum

/* Payload */
fill('W', 1000),
}

and the observed message with that is for example

igc 0000:01:00.0 enp1s0: Detected Tx Unit Hang
Tx Queue <0>
TDH <d0>
TDT <f0>
next_to_use <f0>
next_to_clean <d0>
buffer_info[next_to_clean]
time_stamp <ffff661f>
next_to_watch <00000000245a4efb>
jiffies <ffff6e48>
desc.status <1048000>

Fixes: d8f45be01dd9 ("igc: Use strict cycles for Qbv scheduling")
Signed-off-by: Florian Kauer <florian.kauer@linutronix.de>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Rename qbv_enable to taprio_offload_enable

In the current implementation the flags adapter->qbv_enable
and IGC_FLAG_TSN_QBV_ENABLED have a similar name, but do not
have the same meaning. The first one is used only to indicate
taprio offload (i.e. when igc_save_qbv_schedule was called),
while the second one corresponds to the Qbv mode of the hardware.
However, the second one is also used to support the TX launchtime
feature, i.e. ETF qdisc offload. This leads to situations where
adapter->qbv_enable is false, but the flag IGC_FLAG_TSN_QBV_ENABLED
is set. This is prone to confusion.

The rename should reduce this confusion. Since it is a pure
rename, it has no impact on functionality.

Fixes: e17090eb2494 ("igc: allow BaseTime 0 enrollment for Qbv")
Signed-off-by: Florian Kauer <florian.kauer@linutronix.de>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Fix TX Hang issue when QBV Gate is closed

If a user schedules a Gate Control List (GCL) to close one of
the QBV gates while also transmitting a packet to that closed gate,
TX Hang will be happen. HW would not drop any packet when the gate
is closed and keep queuing up in HW TX FIFO until the gate is re-opened.
This patch implements the solution to drop the packet for the closed
gate.

This patch will also reset the adapter to perform SW initialization
for each 1st Gate Control List (GCL) to avoid hang.
This is due to the HW design, where changing to TSN transmit mode
requires SW initialization. Intel Discrete I225/6 transmit mode
cannot be changed when in dynamic mode according to Software User
Manual Section 7.5.2.1. Subsequent Gate Control List (GCL) operations
will proceed without a reset, as they already are in TSN Mode.

Step to reproduce:

DUT:
1) Configure GCL List with certain gate close.

BASE=$(date +%s%N)
tc qdisc replace dev $IFACE parent root handle 100 taprio \
num_tc 4 \
map 0 1 2 3 3 3 3 3 3 3 3 3 3 3 3 3 \
queues 1@0 1@1 1@2 1@3 \
base-time $BASE \
sched-entry S 0x8 500000 \
sched-entry S 0x4 500000 \
flags 0x2

2) Transmit the packet to closed gate. You may use udp_tai
application to transmit UDP packet to any of the closed gate.

./udp_tai -i <interface> -P 100000 -p 90 -c 1 -t <0/1> -u 30004

Fixes: ec50a9d437f0 ("igc: Add support for taprio offloading")
Co-developed-by: Tan Tee Min <tee.min.tan@linux.intel.com>
Signed-off-by: Tan Tee Min <tee.min.tan@linux.intel.com>
Tested-by: Chwee Lin Choong <chwee.lin.choong@intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Add condition for qbv_config_change_errors counter

Add condition to increase the qbv counter during taprio qbv
configuration only.

There might be a case when TC already been setup then user configure
the ETF/CBS qdisc and this counter will increase if no condition above.

Fixes: ae4fe4698300 ("igc: Add qbv_config_change_errors counter")
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Add qbv_config_change_errors counter

Add ConfigChangeError(qbv_config_change_errors) when user try to set the
AdminBaseTime to past value while the current GCL is still running.

The ConfigChangeError counter should not be increased when a gate control
list is scheduled into the future.

User can use "ethtool -S <interface> | grep qbv_config_change_errors"
command to check the counter values.

Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Remove reset adapter task for i226 during disable tsn config

I225 have limitation when programming the BaseTime register which required
a power cycle of the controller. This limitation already lifted in I226.
This patch removes the restriction so that when user configure/remove any
TSN mode, it would not go into power cycle reset adapter.

How to test:

Schedule any gate control list configuration or delete it.

Example:

1)

BASE_TIME=$(date +%s%N)
tc qdisc replace dev $interface_name parent root handle 100 taprio \
num_tc 4 \
map 3 1 0 2 3 3 3 3 3 3 3 3 3 3 3 3 \
queues 1@0 1@1 1@2 1@3 \
base-time $BASE_TIME \
sched-entry S 0F 1000000 \
flags 0x2

2) tc qdisc del dev $intername_name root

Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: enable Qbv configuration for 2nd GCL

Make reset task only executes for i225 and Qbv disabling to allow
i226 configure for 2nd GCL without resetting the adapter.

In i226, Tx won't hang if there is a GCL is already running, so in
this case we don't need to set FutScdDis bit.

Signed-off-by: Tan Tee Min <tee.min.tan@linux.intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: remove I226 Qbv BaseTime restriction

Remove the Qbv BaseTime restriction for I226 so that the BaseTime can be
scheduled to the future time. A new register bit of Tx Qav Control
(Bit-7: FutScdDis) was introduced to allow I226 scheduling future time as
Qbv BaseTime and not having the Tx hang timeout issue.

Besides, according to datasheet section 7.5.2.9.3.3, FutScdDis bit has to
be configured first before the cycle time and base time.

Indeed the FutScdDis bit is only active on re-configuration, thus we have
to set the BASET_L to zero and then only set it to the desired value.

Please also note that the Qbv configuration flow is moved around based on
the Qbv programming guideline that is documented in the latest datasheet.

Co-developed-by: Tan Tee Min <tee.min.tan@linux.intel.com>
Signed-off-by: Tan Tee Min <tee.min.tan@linux.intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: allow BaseTime 0 enrollment for Qbv

Introduce qbv_enable flag in igc_adapter struct to store the Qbv on/off.
So this allow the BaseTime to enroll with zero value.

Fixes: 61572d5f8f91 ("igc: Simplify TSN flags handling")
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Signed-off-by: Tan Tee Min <tee.min.tan@linux.intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Use strict cycles for Qbv scheduling

Configuring strict cycle mode in the controller forces more well
behaved transmissions when taprio is offloaded.

When set this strict_cycle and strict_end, transmission is not
enabled if the whole packet cannot be completed before end of
the Qbv cycle.

Fixes: 82faa9b79950 ("igc: Add support for ETF offloading")
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Aravindhan Gunasekaran <aravindhan.gunasekaran@intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Correct the launchtime offset

The launchtime offset should be corrected according to sections 7.5.2.6
Transmit Scheduling Latency of the Intel Ethernet I225/I226 Software
User Manual.

Software can compensate the latency between the transmission scheduling
and the time that packet is transmitted to the network by setting this
GTxOffset register. Without setting this register, there may be a
significant delay between the packet scheduling and the network point.

This patch helps to reduce the latency for each of the link speed.

Before:

10Mbps : 11000 - 13800 nanosecond
100Mbps : 1300 - 1700 nanosecond
1000Mbps : 190 - 600 nanosecond
2500Mbps : 1400 - 1700 nanosecond

After:

10Mbps : less than 750 nanosecond
100Mbps : less than 192 nanosecond
1000Mbps : less than 128 nanosecond
2500Mbps : less than 128 nanosecond

Test Setup:

Talker : Use l2_tai.c to generate the launchtime into packet payload.
Listener: Use timedump.c to compute the delta between packet arrival and
LaunchTime packet payload.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Acked-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Add support for CBS offloading

Implement support for Credit-based shaper(CBS) Qdisc hardware
offload mode in the driver. There are two sets of IEEE802.1Qav
(CBS) HW logic in i225 controller and this patch supports
enabling them in the top two priority TX queues.

Driver implemented as recommended by Foxville External
Architecture Specification v0.993. Idleslope and Hi-credit are
the CBS tunable parameters for i225 NIC, programmed in TQAVCC
and TQAVHC registers respectively.

In-order for IEEE802.1Qav (CBS) algorithm to work as intended
and provide BW reservation CBS should be enabled in highest
priority queue first. If we enable CBS on any of low priority
queues, the traffic in high priority queue does not allow low
priority queue to be selected for transmission and bandwidth
reservation is not guaranteed.

Signed-off-by: Aravindhan Gunasekaran <aravindhan.gunasekaran@intel.com>
Signed-off-by: Mallikarjuna Chilakala <mallikarjuna.chilakala@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Simplify TSN flags handling

Separates the procedure done during reset from applying a
configuration, knowing when the code is executing allow us to
separate the better what changes the hardware state from what
changes only the driver state.

Introduces a flag for bookkeeping the driver state of TSN
features. When Qav and frame-preemption is also implemented
this flag makes it easier to keep track on whether a TSN feature
driver state is enabled or not though controller state changes,
say, during a reset.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Aravindhan Gunasekaran <aravindhan.gunasekaran@intel.com>
Signed-off-by: Mallikarjuna Chilakala <mallikarjuna.chilakala@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Use default cycle 'start' and 'end' values for queues

Sets default values for each queue cycle start and cycle end.
This allows some simplification in the handling of these
configurations as most TSN features in i225 require a cycle
to be configured.

In i225, cycle start and end time is required to be programmed
for CBS to work properly.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Aravindhan Gunasekaran <aravindhan.gunasekaran@intel.com>
Signed-off-by: Mallikarjuna Chilakala <mallikarjuna.chilakala@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Set QBVCYCLET_S to 0 for TSN Basic Scheduling

According to datasheet section 8.12.19, when there's no TSN offloading
Shadow_QbvCycle bit[29:0] must be set to zero for basic scheduling.

Signed-off-by: Muhammad Husaini Zulkifli <muhammad.husaini.zulkifli@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

igc: Add support for ETF offloading

This adds support for ETF offloading for the i225 controller.

For i225, the LaunchTime feature is almost a subset of the Qbv
feature. The main change from the i210 is that the launchtime of each
packet is specified as an offset applied to the BASET register. BASET
is automatically incremented each cycle.

For i225, the approach chosen is to re-use most of the setup used for
taprio offloading. With a few changes:

- The more or less obvious one is that when ETF is enabled, we should
set add the expected launchtime to the (advanced) transmit
descriptor;

- The less obvious, is that when taprio offloading is not enabled, we
add a dummy schedule (all queues are open all the time, with a cycle
time of 1 second).

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Andre Guedes <andre.guedes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

igc: Add support for taprio offloading

Adds support for translating taprio schedules into i225 cycles. This
will allow schedules to run in the hardware, making the schedules
enforcement more precise and saving CPU time.

Right now, the only simple schedules are allowed, complex schedules are
rejected. "simple" in this context are schedules that each HW queue is
opened and closed only once in each cycle.

Changing schedules is still not supported as well.

Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Andre Guedes <andre.guedes@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>