ice: work on pre-XDP prog frag count

[ Upstream commit ad2047cf5d9313200e308612aed516548873d124 ]

Fix an OOM panic in XDP_DRV mode when a XDP program shrinks a
multi-buffer packet by 4k bytes and t

ice: work on pre-XDP prog frag count

[ Upstream commit ad2047cf5d9313200e308612aed516548873d124 ]

Fix an OOM panic in XDP_DRV mode when a XDP program shrinks a
multi-buffer packet by 4k bytes and then redirects it to an AF_XDP
socket.

Since support for handling multi-buffer frames was added to XDP, usage
of bpf_xdp_adjust_tail() helper within XDP program can free the page
that given fragment occupies and in turn decrease the fragment count
within skb_shared_info that is embedded in xdp_buff struct. In current
ice driver codebase, it can become problematic when page recycling logic
decides not to reuse the page. In such case, __page_frag_cache_drain()
is used with ice_rx_buf::pagecnt_bias that was not adjusted after
refcount of page was changed by XDP prog which in turn does not drain
the refcount to 0 and page is never freed.

To address this, let us store the count of frags before the XDP program
was executed on Rx ring struct. This will be used to compare with
current frag count from skb_shared_info embedded in xdp_buff. A smaller
value in the latter indicates that XDP prog freed frag(s). Then, for
given delta decrement pagecnt_bias for XDP_DROP verdict.

While at it, let us also handle the EOP frag within
ice_set_rx_bufs_act() to make our life easier, so all of the adjustments
needed to be applied against freed frags are performed in the single
place.

Fixes: 2fba7dc5157b ("ice: Add support for XDP multi-buffer on Rx side")
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20240124191602.566724-5-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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ice: Fix undersized tx_flags variable

As not all ICE_TX_FLAGS_* fit in current 16-bit limited
tx_flags field that was introduced in the Fixes commit,
VLAN-related information would be discarded comp

ice: Fix undersized tx_flags variable

As not all ICE_TX_FLAGS_* fit in current 16-bit limited
tx_flags field that was introduced in the Fixes commit,
VLAN-related information would be discarded completely.
As such, creating a vlan and trying to run ping through
would result in no traffic passing.

Fix that by refactoring tx_flags variable into flags only and
a separate variable that holds VLAN ID. As there is some space left,
type variable can fit between those two. Pahole reports no size
change to ice_tx_buf struct.

Fixes: aa1d3faf71a6 ("ice: Robustify cleaning/completing XDP Tx buffers")
Signed-off-by: Jan Sokolowski <jan.sokolowski@intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ice: Fix freeing XDP frames backed by Page Pool

As already mentioned, freeing any &xdp_frame via page_frag_free() is
wrong, as it assumes the frame is backed by either an order-0 page or
a page with

ice: Fix freeing XDP frames backed by Page Pool

As already mentioned, freeing any &xdp_frame via page_frag_free() is
wrong, as it assumes the frame is backed by either an order-0 page or
a page with no "patrons" behind them, while in fact frames backed by
Page Pool can be redirected to a device, which's driver doesn't use it.
Keep storing a pointer to the raw buffer and then freeing it
unconditionally via page_frag_free() for %XDP_TX frames, but introduce
a separate type in the enum for frames coming through .ndo_xdp_xmit(),
and free them via xdp_return_frame_bulk(). Note that saving xdpf as
xdp_buff->data_hard_start is intentional and is always true when
everything is configured properly.
After this change, %XDP_REDIRECT from a Page Pool based driver to ice
becomes zero-alloc as it should be and horrendous 3.3 Mpps / queue
turn into 6.6, hehe.

Let it go with no "Fixes:" tag as it spans across good 5+ commits and
can't be trivially backported.

Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20230210170618.1973430-6-alexandr.lobakin@intel.com

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ice: Robustify cleaning/completing XDP Tx buffers

When queueing frames from a Page Pool for redirecting to a device backed
by the ice driver, `perf top` shows heavy load on page_alloc() and
page_fra

ice: Robustify cleaning/completing XDP Tx buffers

When queueing frames from a Page Pool for redirecting to a device backed
by the ice driver, `perf top` shows heavy load on page_alloc() and
page_frag_free(), despite that on a properly working system it must be
fully or at least almost zero-alloc. The problem is in fact a bit deeper
and raises from how ice cleans up completed Tx buffers.

The story so far: when cleaning/freeing the resources related to
a particular completed Tx frame (skbs, DMA mappings etc.), ice uses some
heuristics only without setting any type explicitly (except for dummy
Flow Director packets, which are marked via ice_tx_buf::tx_flags).
This kinda works, but only up to some point. For example, currently ice
assumes that each frame coming to __ice_xmit_xdp_ring(), is backed by
either plain order-0 page or plain page frag, while it may also be
backed by Page Pool or any other possible memory models introduced in
future. This means any &xdp_frame must be freed properly via
xdp_return_frame() family with no assumptions.

In order to do that, the whole heuristics must be replaced with setting
the Tx buffer/frame type explicitly, just how it's always been done via
an enum. Let us reuse 16 bits from ::tx_flags -- 1 bit-and instr won't
hurt much -- especially given that sometimes there was a check for
%ICE_TX_FLAGS_DUMMY_PKT, which is now turned from a flag to an enum
member. The rest of the changes is straightforward and most of it is
just a conversion to rely now on the type set in &ice_tx_buf rather than
to some secondary properties.
For now, no functional changes intended, the change only prepares the
ground for starting freeing XDP frames properly next step. And it must
be done atomically/synchronously to not break stuff.

Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20230210170618.1973430-5-alexandr.lobakin@intel.com

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ice: xsk: Do not convert to buff to frame for XDP_TX

Let us store pointer to xdp_buff that came from xsk_buff_pool on tx_buf
so that it will be possible to recycle it via xsk_buff_free() on Tx
clean

ice: xsk: Do not convert to buff to frame for XDP_TX

Let us store pointer to xdp_buff that came from xsk_buff_pool on tx_buf
so that it will be possible to recycle it via xsk_buff_free() on Tx
cleaning side. This way it is not necessary to do expensive copy to
another xdp_buff backed by a newly allocated page.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-14-maciej.fijalkowski@intel.com

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ice: Remove next_{dd,rs} fields from ice_tx_ring

Now that both ZC and standard XDP data paths stopped using Tx logic
based on next_dd and next_rs fields, we can safely remove these fields
and shrink

ice: Remove next_{dd,rs} fields from ice_tx_ring

Now that both ZC and standard XDP data paths stopped using Tx logic
based on next_dd and next_rs fields, we can safely remove these fields
and shrink Tx ring structure.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-13-maciej.fijalkowski@intel.com

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ice: Add support for XDP multi-buffer on Tx side

Similarly as for Rx side in previous patch, logic on XDP Tx in ice
driver needs to be adjusted for multi-buffer support. Specifically, the
way how HW

ice: Add support for XDP multi-buffer on Tx side

Similarly as for Rx side in previous patch, logic on XDP Tx in ice
driver needs to be adjusted for multi-buffer support. Specifically, the
way how HW Tx descriptors are produced and cleaned.

Currently, XDP_TX works on strict ring boundaries, meaning it sets RS
bit (on producer side) / looks up DD bit (on consumer/cleaning side)
every quarter of the ring. It means that if for example multi buffer
frame would span across the ring quarter boundary (say that frame
consists of 4 frames and we start from 62 descriptor where ring is sized
to 256 entries), RS bit would be produced in the middle of multi buffer
frame, which would be a broken behavior as it needs to be set on the
last descriptor of the frame.

To make it work, set RS bit at the last descriptor from the batch of
frames that XDP_TX action was used on and make the first entry remember
the index of last descriptor with RS bit set. This way, cleaning side
can take the index of descriptor with RS bit, look up DD bit's presence
and clean from first entry to last.

In order to clean up the code base introduce the common ice_set_rs_bit()
which will return index of descriptor that got RS bit produced on so
that standard driver can store this within proper ice_tx_buf and ZC
driver can simply ignore return value.

Co-developed-by: Martyna Szapar-Mudlaw <martyna.szapar-mudlaw@linux.intel.com>
Signed-off-by: Martyna Szapar-Mudlaw <martyna.szapar-mudlaw@linux.intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-12-maciej.fijalkowski@intel.com

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ice: Add support for XDP multi-buffer on Rx side

Ice driver needs to be a bit reworked on Rx data path in order to
support multi-buffer XDP. For skb path, it currently works in a way that
Rx ring ca

ice: Add support for XDP multi-buffer on Rx side

Ice driver needs to be a bit reworked on Rx data path in order to
support multi-buffer XDP. For skb path, it currently works in a way that
Rx ring carries pointer to skb so if driver didn't manage to combine
fragmented frame at current NAPI instance, it can restore the state on
next instance and keep looking for last fragment (so descriptor with EOP
bit set). What needs to be achieved is that xdp_buff needs to be
combined in such way (linear + frags part) in the first place. Then skb
will be ready to go in case of XDP_PASS or BPF program being not present
on interface. If BPF program is there, it would work on multi-buffer
XDP. At this point xdp_buff resides directly on Rx ring, so given the
fact that skb will be built straight from xdp_buff, there will be no
further need to carry skb on Rx ring.

Besides removing skb pointer from Rx ring, lots of members have been
moved around within ice_rx_ring. First and foremost reason was to place
rx_buf with xdp_buff on the same cacheline. This means that once we
touch rx_buf (which is a preceding step before touching xdp_buff),
xdp_buff will already be hot in cache. Second thing was that xdp_rxq is
used rather rarely and it occupies a separate cacheline, so maybe it is
better to have it at the end of ice_rx_ring.

Other change that affects ice_rx_ring is the introduction of
ice_rx_ring::first_desc. Its purpose is twofold - first is to propagate
rx_buf->act to all the parts of current xdp_buff after running XDP
program, so that ice_put_rx_buf() that got moved out of the main Rx
processing loop will be able to tak an appriopriate action on each
buffer. Second is for ice_construct_skb().

ice_construct_skb() has a copybreak mechanism which had an explicit
impact on xdp_buff->skb conversion in the new approach when legacy Rx
flag is toggled. It works in a way that linear part is 256 bytes long,
if frame is bigger than that, remaining bytes are going as a frag to
skb_shared_info.

This means while memcpying frags from xdp_buff to newly allocated skb,
care needs to be taken when picking the destination frag array entry.
Upon the time ice_construct_skb() is called, when dealing with
fragmented frame, current rx_buf points to the *last* fragment, but
copybreak needs to be done against the first one. That's where
ice_rx_ring::first_desc helps.

When frame building spans across NAPI polls (DD bit is not set on
current descriptor and xdp->data is not NULL) with current Rx buffer
handling state there might be some problems.
Since calls to ice_put_rx_buf() were pulled out of the main Rx
processing loop and were scoped from cached_ntc to current ntc, remember
that now mentioned function relies on rx_buf->act, which is set within
ice_run_xdp(). ice_run_xdp() is called when EOP bit was found, so
currently we could put Rx buffer with rx_buf->act being *uninitialized*.
To address this, change scoping to rely on first_desc on both boundaries
instead.

This also implies that cleaned_count which is used as an input to
ice_alloc_rx_buffers() and tells how many new buffers should be refilled
has to be adjusted. If it stayed as is, what could happen is a case
where ntc would go over ntu.

Therefore, remove cleaned_count altogether and use against allocing
routine newly introduced ICE_RX_DESC_UNUSED() macro which is an
equivalent of ICE_DESC_UNUSED() dedicated for Rx side and based on
struct ice_rx_ring::first_desc instead of next_to_clean.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-11-maciej.fijalkowski@intel.com

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ice: Centrallize Rx buffer recycling

Currently calls to ice_put_rx_buf() are sprinkled through
ice_clean_rx_irq() - first place is for explicit flow director's
descriptor handling, second is after r

ice: Centrallize Rx buffer recycling

Currently calls to ice_put_rx_buf() are sprinkled through
ice_clean_rx_irq() - first place is for explicit flow director's
descriptor handling, second is after running XDP prog and the last one
is after taking care of skb.

1st callsite was actually only for ntc bump purpose, as Rx buffer to be
recycled is not even passed to a function.

It is possible to walk through Rx buffers processed in particular NAPI
cycle by caching ntc from beginning of the ice_clean_rx_irq().

To do so, let us store XDP verdict inside ice_rx_buf, so action we need
to take on will be known. For XDP prog absence, just store ICE_XDP_PASS
as a verdict.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-7-maciej.fijalkowski@intel.com

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ice: Store page count inside ice_rx_buf

This will allow us to avoid carrying additional auxiliary array of page
counts when dealing with XDP multi buffer support. Previously combining
fragmented fra

ice: Store page count inside ice_rx_buf

This will allow us to avoid carrying additional auxiliary array of page
counts when dealing with XDP multi buffer support. Previously combining
fragmented frame to skb was not affected in the same way as XDP would be
as whole frame is needed to be in place before executing XDP prog.
Therefore, when going through HW Rx descriptors one-by-one, calls to
ice_put_rx_buf() need to be taken *after* running XDP prog on a
potentially multi buffered frame, so some additional storage of
page count is needed.

By adding page count to rx buf, it will make it easier to walk through
processed entries at the end of rx cleaning routine and decide whether
or not buffers should be recycled.

While at it, bump ice_rx_buf::pagecnt_bias from u16 up to u32. It was
proven many times that calculations on variables smaller than standard
register size are harmful. This was also the case during experiments
with embedding page count to ice_rx_buf - when this was added as u16 it
had a performance impact.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-4-maciej.fijalkowski@intel.com

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ice: Add xdp_buff to ice_rx_ring struct

In preparation for XDP multi-buffer support, let's store xdp_buff on
Rx ring struct. This will allow us to combine fragmented frames across
separate NAPI cycl

ice: Add xdp_buff to ice_rx_ring struct

In preparation for XDP multi-buffer support, let's store xdp_buff on
Rx ring struct. 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. For now it is kept and layout of Rx ring struct was
not inspected, some member movement will be needed later on so that will
be the time to take care of it.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-3-maciej.fijalkowski@intel.com

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ice: Prepare legacy-rx for upcoming XDP multi-buffer support

Rx path is going to be modified in a way that fragmented frame will be
gathered within xdp_buff in the first place. This approach implies

ice: Prepare legacy-rx for upcoming XDP multi-buffer support

Rx path is going to be modified in a way that fragmented frame will be
gathered within xdp_buff in the first place. This approach implies that
underlying buffer has to provide tailroom for skb_shared_info. This is
currently the case when ring uses build_skb but not when legacy-rx knob
is turned on. This case configures 2k Rx buffers and has no way to
provide either headroom or tailroom - FWIW it currently has
XDP_PACKET_HEADROOM which is broken and in here it is removed. 2k Rx
buffers were used so driver in this setting was able to support 9k MTU
as it can chain up to 5 Rx buffers. With offset configuring HW writing
2k of a data was passing the half of the page which broke the assumption
of our internal page recycling tricks.

Now if above got fixed and legacy-rx path would be left as is, when
referring to skb_shared_info via xdp_get_shared_info_from_buff(),
packet's content would be corrupted again. Hence size of Rx buffer needs
to be lowered and therefore supported MTU. This operation will allow us
to keep the unified data path and with 8k MTU users (if any of
legacy-rx) would still be good to go. However, tendency is to drop the
support for this code path at some point.

Add ICE_RXBUF_1664 as vsi::rx_buf_len and ICE_MAX_FRAME_LEGACY_RX (8320)
as vsi::max_frame for legacy-rx. For bigger page sizes configure 3k Rx
buffers, not 2k.

Since headroom support is removed, disable data_meta support on legacy-rx.
When preparing XDP buff, rely on ice_rx_ring::rx_offset setting when
deciding whether to support data_meta or not.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20230131204506.219292-2-maciej.fijalkowski@intel.com

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ice: Accumulate ring statistics over reset

Resets may occur with or without user interaction. For example, a TX hang
or reconfiguration of parameters will result in a reset. During reset, the
VSI is

ice: Accumulate ring statistics over reset

Resets may occur with or without user interaction. For example, a TX hang
or reconfiguration of parameters will result in a reset. During reset, the
VSI is freed, freeing any statistics structures inside as well. This would
create an issue for the user where a reset happens in the background,
statistics set to zero, and the user checks ring statistics expecting them
to be populated.

To ensure this doesn't happen, accumulate ring statistics over reset.

Define a new ring statistics structure, ice_ring_stats. The new structure
lives in the VSI's parent, preserving ring statistics when VSI is freed.

1. Define a new structure vsi_ring_stats in the PF scope
2. Allocate/free stats only during probe, unload, or change in ring size
3. Replace previous ring statistics functionality with new structure

Signed-off-by: Benjamin Mikailenko <benjamin.mikailenko@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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ice: Implement control of FCS/CRC stripping

The driver can allow the user to configure whether the CRC aka the FCS
(Frame Check Sequence) is DMA'd to the host as part of the receive
buffer. The dri

ice: Implement control of FCS/CRC stripping

The driver can allow the user to configure whether the CRC aka the FCS
(Frame Check Sequence) is DMA'd to the host as part of the receive
buffer. The driver usually wants this feature disabled so that the
hardware checks the FCS and strips it in order to save PCI bandwidth.

Control the reception of FCS to the host using the command:
ethtool -K eth0 rx-fcs <on|off>

The default shown in ethtool -k eth0 | grep fcs; should be "off", as the
hardware will drop any frame with a bad checksum, and DMA of the
checksum is useless overhead especially for small packets.

Testing Hints:
test the FCS/CRC arrives with received packets using
tcpdump -nnpi eth0 -xxxx
and it should show crc data as the last 4 bytes of the packet. Can also
use wireshark to turn on CRC checking and check the data is correct.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Co-developed-by: Grzegorz Nitka <grzegorz.nitka@intel.com>
Signed-off-by: Grzegorz Nitka <grzegorz.nitka@intel.com>
Co-developed-by: Benjamin Mikailenko <benjamin.mikailenko@intel.com>
Signed-off-by: Benjamin Mikailenko <benjamin.mikailenko@intel.com>
Co-developed-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Signed-off-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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ice: Fix interrupt moderation settings getting cleared

Adaptive-rx and Adaptive-tx are interrupt moderation settings
that can be enabled/disabled using ethtool:
ethtool -C ethX adaptive-rx on/off ad

ice: Fix interrupt moderation settings getting cleared

Adaptive-rx and Adaptive-tx are interrupt moderation settings
that can be enabled/disabled using ethtool:
ethtool -C ethX adaptive-rx on/off adaptive-tx on/off

Unfortunately those settings are getting cleared after
changing number of queues, or in ethtool world 'channels':
ethtool -L ethX rx 1 tx 1

Clearing was happening due to introduction of bit fields
in ice_ring_container struct. This way only itr_setting
bits were rebuilt during ice_vsi_rebuild_set_coalesce().

Introduce an anonymous struct of bitfields and create a
union to refer to them as a single variable.
This way variable can be easily saved and restored.

Fixes: 61dc79ced7aa ("ice: Restore interrupt throttle settings after VSI rebuild")
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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ice, xsk: Terminate Rx side of NAPI when XSK Rx queue gets full

When XSK pool uses need_wakeup feature, correlate -ENOBUFS that was
returned from xdp_do_redirect() with a XSK Rx queue being full. In

ice, xsk: Terminate Rx side of NAPI when XSK Rx queue gets full

When XSK pool uses need_wakeup feature, correlate -ENOBUFS that was
returned from xdp_do_redirect() with a XSK Rx queue being full. In such
case, terminate the Rx processing that is being done on the current HW
Rx ring and let the user space consume descriptors from XSK Rx queue so
that there is room that driver can use later on.

Introduce new internal return code ICE_XDP_EXIT that will indicate case
described above.

Note that it does not affect Tx processing that is bound to the same
NAPI context, nor the other Rx rings.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220413153015.453864-6-maciej.fijalkowski@intel.com

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ice: Add hot path support for 802.1Q and 802.1ad VLAN offloads

Currently the driver only supports 802.1Q VLAN insertion and stripping.
However, once Double VLAN Mode (DVM) is fully supported, then b

ice: Add hot path support for 802.1Q and 802.1ad VLAN offloads

Currently the driver only supports 802.1Q VLAN insertion and stripping.
However, once Double VLAN Mode (DVM) is fully supported, then both 802.1Q
and 802.1ad VLAN insertion and stripping will be supported. Unfortunately
the VSI context parameters only allow for one VLAN ethertype at a time
for VLAN offloads so only one or the other VLAN ethertype offload can be
supported at once.

To support this, multiple changes are needed.

Rx path changes:

[1] In DVM, the Rx queue context l2tagsel field needs to be cleared so
the outermost tag shows up in the l2tag2_2nd field of the Rx flex
descriptor. In Single VLAN Mode (SVM), the l2tagsel field should remain
1 to support SVM configurations.

[2] Modify the ice_test_staterr() function to take a __le16 instead of
the ice_32b_rx_flex_desc union pointer so this function can be used for
both rx_desc->wb.status_error0 and rx_desc->wb.status_error1.

[3] Add the new inline function ice_get_vlan_tag_from_rx_desc() that
checks if there is a VLAN tag in l2tag1 or l2tag2_2nd.

[4] In ice_receive_skb(), add a check to see if NETIF_F_HW_VLAN_STAG_RX
is enabled in netdev->features. If it is, then this is the VLAN
ethertype that needs to be added to the stripping VLAN tag. Since
ice_fix_features() prevents CTAG_RX and STAG_RX from being enabled
simultaneously, the VLAN ethertype will only ever be 802.1Q or 802.1ad.

Tx path changes:

[1] In DVM, the VLAN tag needs to be placed in the l2tag2 field of the Tx
context descriptor. The new define ICE_TX_FLAGS_HW_OUTER_SINGLE_VLAN was
added to the list of tx_flags to handle this case.

[2] When the stack requests the VLAN tag to be offloaded on Tx, the
driver needs to set either ICE_TX_FLAGS_HW_OUTER_SINGLE_VLAN or
ICE_TX_FLAGS_HW_VLAN, so the tag is inserted in l2tag2 or l2tag1
respectively. To determine which location to use, set a bit in the Tx
ring flags field during ring allocation that can be used to determine
which field to use in the Tx descriptor. In DVM, always use l2tag2,
and in SVM, always use l2tag1.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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ice: xsk: Borrow xdp_tx_active logic from i40e

One of the things that commit 5574ff7b7b3d ("i40e: optimize AF_XDP Tx
completion path") introduced was the @xdp_tx_active field. Its usage
from i40e ca

ice: xsk: Borrow xdp_tx_active logic from i40e

One of the things that commit 5574ff7b7b3d ("i40e: optimize AF_XDP Tx
completion path") introduced was the @xdp_tx_active field. Its usage
from i40e can be adjusted to ice driver and give us positive performance
results.

If the descriptor that @next_dd points to has been sent by HW (its DD
bit is set), then we are sure that at least quarter of the ring is ready
to be cleaned. If @xdp_tx_active is 0 which means that related xdp_ring
is not used for XDP_{TX, REDIRECT} workloads, then we know how many XSK
entries should placed to completion queue, IOW walking through the ring
can be skipped.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20220125160446.78976-9-maciej.fijalkowski@intel.com

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ice: xsk: Improve AF_XDP ZC Tx and use batching API

Apply the logic that was done for regular XDP from commit 9610bd988df9
("ice: optimize XDP_TX workloads") to the ZC side of the driver. On top
of

ice: xsk: Improve AF_XDP ZC Tx and use batching API

Apply the logic that was done for regular XDP from commit 9610bd988df9
("ice: optimize XDP_TX workloads") to the ZC side of the driver. On top
of that, introduce batching to Tx that is inspired by i40e's
implementation with adjustments to the cleaning logic - take into the
account NAPI budget in ice_clean_xdp_irq_zc().

Separating the stats structs onto separate cache lines seemed to improve
the performance.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20220125160446.78976-8-maciej.fijalkowski@intel.com

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ice: Make Tx threshold dependent on ring length

XDP_TX workloads use a concept of Tx threshold that indicates the
interval of setting RS bit on descriptors which in turn tells the HW to
generate an

ice: Make Tx threshold dependent on ring length

XDP_TX workloads use a concept of Tx threshold that indicates the
interval of setting RS bit on descriptors which in turn tells the HW to
generate an interrupt to signal the completion of Tx on HW side. It is
currently based on a constant value of 32 which might not work out well
for various sizes of ring combined with for example batch size that can
be set via SO_BUSY_POLL_BUDGET.

Internal tests based on AF_XDP showed that most convenient setup of
mentioned threshold is when it is equal to quarter of a ring length.

Make use of recently introduced ICE_RING_QUARTER macro and use this
value as a substitute for ICE_TX_THRESH.

Align also ethtool -G callback so that next_dd/next_rs fields are up to
date in terms of the ring size.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20220125160446.78976-5-maciej.fijalkowski@intel.com

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ice: xsk: Handle SW XDP ring wrap and bump tail more often

Currently, if ice_clean_rx_irq_zc() processed the whole ring and
next_to_use != 0, then ice_alloc_rx_buf_zc() would not refill the whole
ri

ice: xsk: Handle SW XDP ring wrap and bump tail more often

Currently, if ice_clean_rx_irq_zc() processed the whole ring and
next_to_use != 0, then ice_alloc_rx_buf_zc() would not refill the whole
ring even if the XSK buffer pool would have enough free entries (either
from fill ring or the internal recycle mechanism) - it is because ring
wrap is not handled.

Improve the logic in ice_alloc_rx_buf_zc() to address the problem above.
Do not clamp the count of buffers that is passed to
xsk_buff_alloc_batch() in case when next_to_use + buffer count >=
rx_ring->count, but rather split it and have two calls to the mentioned
function - one for the part up until the wrap and one for the part after
the wrap.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/bpf/20220125160446.78976-4-maciej.fijalkowski@intel.com

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ice: xsk: fix cleaned_count setting

Currently cleaned_count is initialized to ICE_DESC_UNUSED(rx_ring) and
later on during the Rx processing it is incremented per each frame that
driver consumed. Th

ice: xsk: fix cleaned_count setting

Currently cleaned_count is initialized to ICE_DESC_UNUSED(rx_ring) and
later on during the Rx processing it is incremented per each frame that
driver consumed. This can result in excessive buffers requested from xsk
pool based on that value.

To address this, just drop cleaned_count and pass
ICE_DESC_UNUSED(rx_ring) directly as a function argument to
ice_alloc_rx_bufs_zc(). Idea is to ask for buffers as many as consumed.

Let us also call ice_alloc_rx_bufs_zc unconditionally at the end of
ice_clean_rx_irq_zc. This has been changed in that way for corresponding
ice_clean_rx_irq, but not here.

Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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ice: Add infrastructure for mqprio support via ndo_setup_tc

Add infrastructure required for "ndo_setup_tc:qdisc_mqprio".
ice_vsi_setup is modified to configure traffic classes based
on mqprio data r

ice: Add infrastructure for mqprio support via ndo_setup_tc

Add infrastructure required for "ndo_setup_tc:qdisc_mqprio".
ice_vsi_setup is modified to configure traffic classes based
on mqprio data received from the stack. This includes low-level
functions to configure min, max rate-limit parameters in hardware
for traffic classes. Each traffic class gets mapped to a hardware
channel (VSI) which can be individually configured with different
bandwidth parameters.

Co-developed-by: Tarun Singh <tarun.k.singh@intel.com>
Signed-off-by: Tarun Singh <tarun.k.singh@intel.com>
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
Tested-by: Bharathi Sreenivas <bharathi.sreenivas@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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ice: introduce XDP_TX fallback path

Under rare circumstances there might be a situation where a requirement
of having XDP Tx queue per CPU could not be fulfilled and some of the Tx
resources have to

ice: introduce XDP_TX fallback path

Under rare circumstances there might be a situation where a requirement
of having XDP Tx queue per CPU could not be fulfilled and some of the Tx
resources have to be shared between CPUs. This yields a need for placing
accesses to xdp_ring inside a critical section protected by spinlock.
These accesses happen to be in the hot path, so let's introduce the
static branch that will be triggered from the control plane when driver
could not provide Tx queue dedicated for XDP on each CPU.

Currently, the design that has been picked is to allow any number of XDP
Tx queues that is at least half of a count of CPUs that platform has.
For lower number driver will bail out with a response to user that there
were not enough Tx resources that would allow configuring XDP. The
sharing of rings is signalled via static branch enablement which in turn
indicates that lock for xdp_ring accesses needs to be taken in hot path.

Approach based on static branch has no impact on performance of a
non-fallback path. One thing that is needed to be mentioned is a fact
that the static branch will act as a global driver switch, meaning that
if one PF got out of Tx resources, then other PFs that ice driver is
servicing will suffer. However, given the fact that HW that ice driver
is handling has 1024 Tx queues per each PF, this is currently an
unlikely scenario.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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ice: optimize XDP_TX workloads

Optimize Tx descriptor cleaning for XDP. Current approach doesn't
really scale and chokes when multiple flows are handled.

Introduce two ring fields, @next_dd and @ne

ice: optimize XDP_TX workloads

Optimize Tx descriptor cleaning for XDP. Current approach doesn't
really scale and chokes when multiple flows are handled.

Introduce two ring fields, @next_dd and @next_rs that will keep track of
descriptor that should be looked at when the need for cleaning arise and
the descriptor that should have the RS bit set, respectively.

Note that at this point the threshold is a constant (32), but it is
something that we could make configurable.

First thing is to get away from setting RS bit on each descriptor. Let's
do this only once NTU is higher than the currently @next_rs value. In
such case, grab the tx_desc[next_rs], set the RS bit in descriptor and
advance the @next_rs by a 32.

Second thing is to clean the Tx ring only when there are less than 32
free entries. For that case, look up the tx_desc[next_dd] for a DD bit.
This bit is written back by HW to let the driver know that xmit was
successful. It will happen only for those descriptors that had RS bit
set. Clean only 32 descriptors and advance the DD bit.

Actual cleaning routine is moved from ice_napi_poll() down to the
ice_xmit_xdp_ring(). It is safe to do so as XDP ring will not get any
SKBs in there that would rely on interrupts for the cleaning. Nice side
effect is that for rare case of Tx fallback path (that next patch is
going to introduce) we don't have to trigger the SW irq to clean the
ring.

With those two concepts, ring is kept at being almost full, but it is
guaranteed that driver will be able to produce Tx descriptors.

This approach seems to work out well even though the Tx descriptors are
produced in one-by-one manner. Test was conducted with the ice HW
bombarded with packets from HW generator, configured to generate 30
flows.

Xdp2 sample yields the following results:
<snip>
proto 17: 79973066 pkt/s
proto 17: 80018911 pkt/s
proto 17: 80004654 pkt/s
proto 17: 79992395 pkt/s
proto 17: 79975162 pkt/s
proto 17: 79955054 pkt/s
proto 17: 79869168 pkt/s
proto 17: 79823947 pkt/s
proto 17: 79636971 pkt/s
</snip>

As that sample reports the Rx'ed frames, let's look at sar output.
It says that what we Rx'ed we do actually Tx, no noticeable drops.
Average: IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s %ifutil
Average: ens4f1 79842324.00 79842310.40 4678261.17 4678260.38 0.00 0.00 0.00 38.32

with tx_busy staying calm.

When compared to a state before:
Average: IFACE rxpck/s txpck/s rxkB/s txkB/s rxcmp/s txcmp/s rxmcst/s %ifutil
Average: ens4f1 90919711.60 42233822.60 5327326.85 2474638.04 0.00 0.00 0.00 43.64

it can be observed that the amount of txpck/s is almost doubled, meaning
that the performance is improved by around 90%. All of this due to the
drops in the driver, previously the tx_busy stat was bumped at a 7mpps
rate.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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