i40e: add xdp_buff to i40e_ring struct

Store xdp_buff on Rx ring struct in preparation for XDP multi-buffer
support. This will allow us to combine fragmented frames across
separate NAPI cycles in the same way as currently skb fragments are
handled. This means that skb pointer on Rx ring will become redundant
and will be removed in a later patch. As a consequence i40e_trace() now
uses xdp instead of skb pointer.

Truesize only needs to be calculated for page sizes bigger than 4k as it
is always half-page for 4k pages. With xdp_buff on ring, frame size can
now be set during xdp_init_buff() and need not be repopulated in each
NAPI call for 4k pages. As a consequence i40e_rx_frame_truesize() is now
used only for bigger pages.

Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

i40e: Add i40e_napi_poll tracepoint

Add a tracepoint for i40e_napi_poll that allows users to get detailed
information about the amount of work done. This information can help users
better tune the correct NAPI parameters (like weight and budget), as well
as debug NIC settings like rx-usecs and tx-usecs, etc.

When perf is attached, this tracepoint only fires when not in XDP mode.

An example of the output from this tracepoint:

$ sudo perf trace -e i40e:i40e_napi_poll -a --call-graph=fp --libtraceevent_print

[..snip..]

388.258 :0/0 i40e:i40e_napi_poll(i40e_napi_poll on dev eth2 q i40e-eth2-TxRx-9 irq 346 irq_mask 00000000,00000000,00000000,00000000,00000000,00800000 curr_cpu 23 budget 64 bpr 64 rx_cleaned 28 tx_cleaned 0 rx_clean_complete 1 tx_clean_complete 1)
i40e_napi_poll ([i40e])
i40e_napi_poll ([i40e])
__napi_poll ([kernel.kallsyms])
net_rx_action ([kernel.kallsyms])
__do_softirq ([kernel.kallsyms])
common_interrupt ([kernel.kallsyms])
asm_common_interrupt ([kernel.kallsyms])
intel_idle_irq ([kernel.kallsyms])
cpuidle_enter_state ([kernel.kallsyms])
cpuidle_enter ([kernel.kallsyms])
do_idle ([kernel.kallsyms])
cpu_startup_entry ([kernel.kallsyms])
[0x243fd8] ([kernel.kallsyms])
secondary_startup_64_no_verify ([kernel.kallsyms])

Signed-off-by: Joe Damato <jdamato@fastly.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

intel-ethernet: clean up W=1 warnings in kdoc

This takes care of all of the trivial W=1 fixes in the Intel
Ethernet drivers, which allows developers and maintainers to
build more of the networking tree with more complete warning
checks.

There are three classes of kdoc warnings fixed:
- cannot understand function prototype: 'x'
- Excess function parameter 'x' description in 'y'
- Function parameter or member 'x' not described in 'y'

All of the changes were trivial comment updates on
function headers.

Inspired by Lee Jones' series of wireless work to do the same.
Compile tested only, and passes simple test of
$ git ls-files *.[ch] | egrep drivers/net/ethernet/intel | \
xargs scripts/kernel-doc -none

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

i40e: use 16B HW descriptors instead of 32B

The i40e NIC supports two flavors of HW descriptors, 16 and 32
byte. The latter has, obviously, room for more offloading
information. However, the only fields of the 32B HW descriptor that is
being used by the driver, is also available in the 16B descriptor.

In other words; Reading and writing 32 bytes instead of 16 byte is a
waste of bus bandwidth.

This commit starts using 16 byte descriptors instead of 32 byte
descriptors.

For AF_XDP the rx_drop benchmark was improved by 2%.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

net: intel: Cleanup the copyright/license headers

After many years of having a ~30 line copyright and license header to our
source files, we are finally able to reduce that to one line with the
advent of the SPDX identifier.

Also caught a few files missing the SPDX license identifier, so fixed
them up.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Shannon Nelson <shannon.nelson@oracle.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

intel: add SPDX identifiers to all the Intel drivers

Add the SPDX identifiers to all the Intel wired LAN driver files, as
outlined in Documentation/process/license-rules.rst.

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

i40e/i40evf: Add tracepoints

This patch adds tracepoints to the i40e and i40evf drivers to which
BPF programs can be attached for feature testing and verification.
It's expected that an attached BPF program will identify and count or
log some interesting subset of traffic. The bcc-tools package is
helpful there for containing all the BPF arcana in a handy Python
wrapper. Though you can make these tracepoints log trace messages, the
messages themselves probably won't be very useful (other to verify the
tracepoint is being called while you're debugging your BPF program).

The idea here is that tracepoints have such low performance cost when
disabled that we can leave these in the upstream drivers. This may
eventually enable the instrumentation of unmodified customer systems
should the need arise to verify a NIC feature is working as expected.
In general this enables one set of feature verification tools to be
used on these drivers whether they're built with the kernel or
separately.

Users are advised against using these tracepoints for anything other
than a diagnostic tool. They have a performance impact when enabled,
and their exact placement and form may change as we see how well they
work in practice for the purposes above.

Change-ID: Id6014a7322c0e6d08068114dd20bd156f2f6435e
Signed-off-by: Scott Peterson <scott.d.peterson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>