eth: add missing xdp.h includes in drivers

Handful of drivers currently expect to get xdp.h by virtue
of including netdevice.h. This will soon no longer be the case
so add explicit includes.

Review

eth: add missing xdp.h includes in drivers

Handful of drivers currently expect to get xdp.h by virtue
of including netdevice.h. This will soon no longer be the case
so add explicit includes.

Reviewed-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/20230803010230.1755386-2-kuba@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

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net: enetc: refactor enetc_setup_tc_taprio() to have a switch/case for cmd

Make enetc_setup_tc_taprio() more amenable to future extensions, like
reporting statistics.

Signed-off-by: Vladimir Oltean

net: enetc: refactor enetc_setup_tc_taprio() to have a switch/case for cmd

Make enetc_setup_tc_taprio() more amenable to future extensions, like
reporting statistics.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: enetc: only commit preemptible TCs to hardware when MM TX is active

This was left as TODO in commit 01e23b2b3bad ("net: enetc: add support
for preemptible traffic classes") since it's relativel

net: enetc: only commit preemptible TCs to hardware when MM TX is active

This was left as TODO in commit 01e23b2b3bad ("net: enetc: add support
for preemptible traffic classes") since it's relatively complicated.

Where this makes a difference is with a configuration as follows:

ethtool --set-mm eno0 pmac-enabled on tx-enabled on verify-enabled on

Preemptible packets should only be sent when the MAC Merge TX direction
becomes active (i.o.w. when the verification process succeeds, aka when
the link partner confirms it can process preemptible traffic). But the
tc qdisc with the preemptible traffic classes is offloaded completely
asynchronously w.r.t. the MM becoming active.

The ENETC manual does suggest that this should be handled in the driver:
"On startup, software should wait for the verification process to
complete (MMCSR[VSTS]=011) before initiating traffic".

Adding the necessary logic allows future selftests to uphold the claim
that an inactive or disabled MAC Merge layer should never send data
packets through the pMAC.

This change moves enetc_set_ptcfpr() from enetc.c to enetc_ethtool.c,
where its only caller is now - enetc_mm_commit_preemptible_tcs().

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: add support for preemptible traffic classes

PFs which support the MAC Merge layer also have a set of 8 registers
called "Port traffic class N frame preemption register (PTC0FPR - PTC7FPR

net: enetc: add support for preemptible traffic classes

PFs which support the MAC Merge layer also have a set of 8 registers
called "Port traffic class N frame preemption register (PTC0FPR - PTC7FPR)".
Through these, a traffic class (group of TX rings of same dequeue
priority) can be mapped to the eMAC or to the pMAC.

There's nothing particularly spectacular here. We should probably only
commit the preemptible TCs to hardware once the MAC Merge layer became
active, but unlike Felix, we don't have an IRQ that notifies us of that.
We'd have to sleep for up to verifyTime (127 ms) to wait for a
resolution coming from the verification state machine; not only from the
ndo_setup_tc() code path, but also from enetc_mm_link_state_update().
Since it's relatively complicated and has a relatively small benefit,
I'm not doing it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ferenc Fejes <fejes@inf.elte.hu>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: add support for MAC Merge layer

Add PF driver support for viewing and changing the MAC Merge sublayer
parameters, and seeing the verification state machine's current state.
The verificat

net: enetc: add support for MAC Merge layer

Add PF driver support for viewing and changing the MAC Merge sublayer
parameters, and seeing the verification state machine's current state.
The verification handshake with the link partner is driven by hardware.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230206094531.444988-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: ensure we always have a minimum number of TXQs for stack

Currently it can happen that an mqprio qdisc is installed with num_tc 8,
and this will reserve 8 (out of 8) TXQs for the network

net: enetc: ensure we always have a minimum number of TXQs for stack

Currently it can happen that an mqprio qdisc is installed with num_tc 8,
and this will reserve 8 (out of 8) TXQs for the network stack. Then we
can attach an XDP program, and this will crop 2 TXQs, leaving just 6 for
mqprio. That's not what the user requested, and we should fail it.

On the other hand, if mqprio isn't requested, we still give the 8 TXQs
to the network stack (with hashing among a single traffic class), but
then, cropping 2 TXQs for XDP is fine, because the user didn't
explicitly ask for any number of TXQs, so no expectations are violated.

Simply put, the logic that mqprio should impose a minimum number of TXQs
for the network never existed. Let's say (more or less arbitrarily) that
without mqprio, the driver expects a minimum number of TXQs equal to the
number of CPUs (on NXP LS1028A, that is either 1, or 2). And with mqprio,
mqprio gives the minimum required number of TXQs.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: implement software lockstep for port MAC registers

Currently the enetc driver duplicates its writes to the PM0 registers
also to PM1, but it doesn't do this consistently - for example we

net: enetc: implement software lockstep for port MAC registers

Currently the enetc driver duplicates its writes to the PM0 registers
also to PM1, but it doesn't do this consistently - for example we write
to ENETC_PM0_MAXFRM but not to ENETC_PM1_MAXFRM.

Create enetc_port_mac_wr() which writes both the PM0 and PM1 register
with the same value (if frame preemption is supported on this port).
Also create enetc_port_mac_rd() which reads from PM0 - the assumption
being that PM1 contains just the same value.

This will be necessary when we enable the MAC Merge layer properly, and
the pMAC becomes operational.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: enetc: detect frame preemption hardware capability

Similar to other TSN features, query the Station Interface capability
register to see whether preemption is supported on this port or not.
On

net: enetc: detect frame preemption hardware capability

Similar to other TSN features, query the Station Interface capability
register to see whether preemption is supported on this port or not.
On LS1028A, preemption is available on ports 0 and 2, but not on 1
and 3.

This will allow us in the future to write the pMAC registers only on the
ENETC ports where a pMAC actually exists.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: enetc: rename "xdp" and "dev" in enetc_setup_bpf()

Follow the convention from this driver, which is to name "struct
net_device *" as "ndev", and the convention from other drivers, to name
"stru

net: enetc: rename "xdp" and "dev" in enetc_setup_bpf()

Follow the convention from this driver, which is to name "struct
net_device *" as "ndev", and the convention from other drivers, to name
"struct netdev_bpf *" as "bpf".

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: split ring resource allocation from assignment

We have a few instances in the enetc driver where the ring resources
(BD ring iomem, software BD ring, software TSO headers, basically
ever

net: enetc: split ring resource allocation from assignment

We have a few instances in the enetc driver where the ring resources
(BD ring iomem, software BD ring, software TSO headers, basically
everything except RX buffers) need to be reallocated. For example, when
RX timestamping is enabled, the RX BD format changes to an extended one
(twice as large).

Currently, this is done using a simplistic enetc_close() -> enetc_open()
procedure. But this is quite crude, since it also invokes phylink_stop()
-> phylink_start(), the link is lost, and a few seconds need to pass for
autoneg to complete again.

In fact it's bad also due to the improper (yolo) error checking. In case
we fail to allocate new resources, we've already freed the old ones, so
the interface is more or less stuck.

To avoid that, we need a system where reconfiguration is possible in a
way in which resources are allocated upfront. This means that there will
be a higher memory usage temporarily, but the assignment of resources to
rings can be done when both the old and new resources are still available.

Introduce a struct enetc_bdr_resource which holds the resources for a
ring, be it RX or TX. This structure duplicates a lot of fields from
struct enetc_bdr (and access to the same fields in the ring structure
was left duplicated, to not change cache characteristics in the fast
path).

When enetc_alloc_tx_resources() runs, it returns an array of resource
elements (one per TX ring), in addition to the existing priv->tx_res.
To populate priv->tx_res with that array, one must call
enetc_assign_tx_resources(), and this also frees the old resources.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ethernet: enetc: get rid of xdp_redirect_sg counter

Remove xdp_redirect_sg counter and the related ethtool entry since it is
no longer used.

Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com

net: ethernet: enetc: get rid of xdp_redirect_sg counter

Remove xdp_redirect_sg counter and the related ethtool entry since it is
no longer used.

Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: preserve TX ring priority across reconfiguration

In the blamed commit, a rudimentary reallocation procedure for RX buffer
descriptors was implemented, for the situation when their format

net: enetc: preserve TX ring priority across reconfiguration

In the blamed commit, a rudimentary reallocation procedure for RX buffer
descriptors was implemented, for the situation when their format changes
between normal (no PTP) and extended (PTP).

enetc_hwtstamp_set() calls enetc_close() and enetc_open() in a sequence,
and this sequence loses information which was previously configured in
the TX BDR Mode Register, specifically via the enetc_set_bdr_prio() call.
The TX ring priority is configured by tc-mqprio and tc-taprio, and
affects important things for TSN such as the TX time of packets. The
issue manifests itself most visibly by the fact that isochron --txtime
reports premature packet transmissions when PTP is first enabled on an
enetc interface.

Save the TX ring priority in a new field in struct enetc_bdr (occupies a
2 byte hole on arm64) in order to make this survive a ring reconfiguration.

Fixes: 434cebabd3a2 ("enetc: Add dynamic allocation of extended Rx BD rings")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/r/20221122130936.1704151-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: offload per-tc max SDU from tc-taprio

The driver currently sets the PTCMSDUR register statically to the max
MTU supported by the interface. Keep this logic if tc-taprio is absent
or if t

net: enetc: offload per-tc max SDU from tc-taprio

The driver currently sets the PTCMSDUR register statically to the max
MTU supported by the interface. Keep this logic if tc-taprio is absent
or if the max_sdu for a traffic class is 0, and follow the requested max
SDU size otherwise.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: cache accesses to &priv->si->hw

The &priv->si->hw construct dereferences 2 pointers and makes lines
longer than they need to be, in turn making the code harder to read.

Replace &priv->s

net: enetc: cache accesses to &priv->si->hw

The &priv->si->hw construct dereferences 2 pointers and makes lines
longer than they need to be, in turn making the code harder to read.

Replace &priv->si->hw accesses with a "hw" variable when there are 2 or
more accesses within a function that dereference this. This includes
loops, since &priv->si->hw is a loop invariant.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: deny offload of tc-based TSN features on VF interfaces

TSN features on the ENETC (taprio, cbs, gate, police) are configured
through a mix of command BD ring messages and port registers:

net: enetc: deny offload of tc-based TSN features on VF interfaces

TSN features on the ENETC (taprio, cbs, gate, police) are configured
through a mix of command BD ring messages and port registers:
enetc_port_rd(), enetc_port_wr().

Port registers are a region of the ENETC memory map which are only
accessible from the PCIe Physical Function. They are not accessible from
the Virtual Functions.

Moreover, attempting to access these registers crashes the kernel:

$ echo 1 > /sys/bus/pci/devices/0000\:00\:00.0/sriov_numvfs
pci 0000:00:01.0: [1957:ef00] type 00 class 0x020001
fsl_enetc_vf 0000:00:01.0: Adding to iommu group 15
fsl_enetc_vf 0000:00:01.0: enabling device (0000 -> 0002)
fsl_enetc_vf 0000:00:01.0 eno0vf0: renamed from eth0
$ tc qdisc replace dev eno0vf0 root taprio num_tc 8 map 0 1 2 3 4 5 6 7 \
queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 0 \
sched-entry S 0x7f 900000 sched-entry S 0x80 100000 flags 0x2
Unable to handle kernel paging request at virtual address ffff800009551a08
Internal error: Oops: 96000007 [#1] PREEMPT SMP
pc : enetc_setup_tc_taprio+0x170/0x47c
lr : enetc_setup_tc_taprio+0x16c/0x47c
Call trace:
enetc_setup_tc_taprio+0x170/0x47c
enetc_setup_tc+0x38/0x2dc
taprio_change+0x43c/0x970
taprio_init+0x188/0x1e0
qdisc_create+0x114/0x470
tc_modify_qdisc+0x1fc/0x6c0
rtnetlink_rcv_msg+0x12c/0x390

Split enetc_setup_tc() into separate functions for the PF and for the
VF drivers. Also remove enetc_qos.o from being included into
enetc-vf.ko, since it serves absolutely no purpose there.

Fixes: 34c6adf1977b ("enetc: Configure the Time-Aware Scheduler via tc-taprio offload")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220916133209.3351399-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: move enetc_set_psfp() out of the common enetc_set_features()

The VF netdev driver shouldn't respond to changes in the NETIF_F_HW_TC
flag; only PFs should. Moreover, TSN-specific code sho

net: enetc: move enetc_set_psfp() out of the common enetc_set_features()

The VF netdev driver shouldn't respond to changes in the NETIF_F_HW_TC
flag; only PFs should. Moreover, TSN-specific code should go to
enetc_qos.c, which should not be included in the VF driver.

Fixes: 79e499829f3f ("net: enetc: add hw tc hw offload features for PSPF capability")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220916133209.3351399-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: enetc: count the tc-taprio window drops

The enetc scheduler for IEEE 802.1Qbv has 2 options (depending on
PTGCR[TG_DROP_DISABLE]) when we attempt to send an oversized packet
which will never fi

net: enetc: count the tc-taprio window drops

The enetc scheduler for IEEE 802.1Qbv has 2 options (depending on
PTGCR[TG_DROP_DISABLE]) when we attempt to send an oversized packet
which will never fit in its allotted time slot for its traffic class:
either block the entire port due to head-of-line blocking, or drop the
packet and set a bit in the writeback format of the transmit buffer
descriptor, allowing other packets to be sent.

We obviously choose the second option in the driver, but we do not
detect the drop condition, so from the perspective of the network stack,
the packet is sent and no error counter is incremented.

This change checks the writeback of the TX BD when tc-taprio is enabled,
and increments a specific ethtool statistics counter and a generic
"tx_dropped" counter in ndo_get_stats64.

Signed-off-by: Po Liu <Po.Liu@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net:enetc: command BD ring data memory alloc as one function alone

Separate the CBDR data memory alloc standalone. It is convenient for
other part loading, for example the ENETC QOS part.

Reported-

net:enetc: command BD ring data memory alloc as one function alone

Separate the CBDR data memory alloc standalone. It is convenient for
other part loading, for example the ENETC QOS part.

Reported-and-suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Po Liu <po.liu@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: enetc: add support for software TSO

This patch adds support for driver level TSO in the enetc driver using
the TSO API.

Beside using the usual tso_build_hdr(), tso_build_data() this specific
i

net: enetc: add support for software TSO

This patch adds support for driver level TSO in the enetc driver using
the TSO API.

Beside using the usual tso_build_hdr(), tso_build_data() this specific
implementation also has to compute the checksum, both IP and L4, for
each resulted segment. This is because the ENETC controller does not
support Tx checksum offload which is needed in order to take advantage
of TSO.

With the workaround for the ENETC MDIO erratum in place the Tx path of
the driver is forced to lock/unlock for each skb sent. This is why, even
though we are computing the checksum by hand we see the following
improvement in TCP termination on the LS1028A SoC, on a single A72 core
running at 1.3GHz:

before: 1.63 Gbits/sec
after: 2.34 Gbits/sec

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: enetc: deny offload of tc-based TSN features on VF interfaces

[ Upstream commit 5641c751fe2f92d3d9e8a8e03c1263ac8caa0b42 ]

TSN features on the ENETC (taprio, cbs, gate, police) are configured

net: enetc: deny offload of tc-based TSN features on VF interfaces

[ Upstream commit 5641c751fe2f92d3d9e8a8e03c1263ac8caa0b42 ]

TSN features on the ENETC (taprio, cbs, gate, police) are configured
through a mix of command BD ring messages and port registers:
enetc_port_rd(), enetc_port_wr().

Port registers are a region of the ENETC memory map which are only
accessible from the PCIe Physical Function. They are not accessible from
the Virtual Functions.

Moreover, attempting to access these registers crashes the kernel:

$ echo 1 > /sys/bus/pci/devices/0000\:00\:00.0/sriov_numvfs
pci 0000:00:01.0: [1957:ef00] type 00 class 0x020001
fsl_enetc_vf 0000:00:01.0: Adding to iommu group 15
fsl_enetc_vf 0000:00:01.0: enabling device (0000 -> 0002)
fsl_enetc_vf 0000:00:01.0 eno0vf0: renamed from eth0
$ tc qdisc replace dev eno0vf0 root taprio num_tc 8 map 0 1 2 3 4 5 6 7 \
queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 base-time 0 \
sched-entry S 0x7f 900000 sched-entry S 0x80 100000 flags 0x2
Unable to handle kernel paging request at virtual address ffff800009551a08
Internal error: Oops: 96000007 [#1] PREEMPT SMP
pc : enetc_setup_tc_taprio+0x170/0x47c
lr : enetc_setup_tc_taprio+0x16c/0x47c
Call trace:
enetc_setup_tc_taprio+0x170/0x47c
enetc_setup_tc+0x38/0x2dc
taprio_change+0x43c/0x970
taprio_init+0x188/0x1e0
qdisc_create+0x114/0x470
tc_modify_qdisc+0x1fc/0x6c0
rtnetlink_rcv_msg+0x12c/0x390

Split enetc_setup_tc() into separate functions for the PF and for the
VF drivers. Also remove enetc_qos.o from being included into
enetc-vf.ko, since it serves absolutely no purpose there.

Fixes: 34c6adf1977b ("enetc: Configure the Time-Aware Scheduler via tc-taprio offload")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220916133209.3351399-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

net: enetc: move enetc_set_psfp() out of the common enetc_set_features()

[ Upstream commit fed38e64d9b99d65a36c0dbadc3d3f8ddd9ea030 ]

The VF netdev driver shouldn't respond to changes in the NETIF_

net: enetc: move enetc_set_psfp() out of the common enetc_set_features()

[ Upstream commit fed38e64d9b99d65a36c0dbadc3d3f8ddd9ea030 ]

The VF netdev driver shouldn't respond to changes in the NETIF_F_HW_TC
flag; only PFs should. Moreover, TSN-specific code should go to
enetc_qos.c, which should not be included in the VF driver.

Fixes: 79e499829f3f ("net: enetc: add hw tc hw offload features for PSPF capability")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220916133209.3351399-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

net: enetc: create a common enetc_pf_to_port helper

Even though ENETC interfaces are exposed as individual PCIe PFs with
their own driver instances, the ENETC is still fundamentally a
multi-port Eth

net: enetc: create a common enetc_pf_to_port helper

Even though ENETC interfaces are exposed as individual PCIe PFs with
their own driver instances, the ENETC is still fundamentally a
multi-port Ethernet controller, and some parts of the IP take a port
number (as can be seen in the PSFP implementation).

Create a common helper that can be used outside of the TSN code for
retrieving the ENETC port number based on the PF number. This is only
correct for LS1028A, the only Linux-capable instantiation of ENETC thus
far.

Note that ENETC port 3 is PF 6. The TSN code did not care about this
because ENETC port 3 does not support TSN, so the wrong mapping done by
enetc_get_port for PF 6 could have never been hit.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: enetc: use dedicated TX rings for XDP

It is possible for one CPU to perform TX hashing (see netdev_pick_tx)
between the 8 ENETC TX rings, and the TX hashing to select TX queue 1.

At the same t

net: enetc: use dedicated TX rings for XDP

It is possible for one CPU to perform TX hashing (see netdev_pick_tx)
between the 8 ENETC TX rings, and the TX hashing to select TX queue 1.

At the same time, it is possible for the other CPU to already use TX
ring 1 for XDP (either XDP_TX or XDP_REDIRECT). Since there is no mutual
exclusion between XDP and the network stack, we run into an issue
because the ENETC TX procedure is not reentrant.

The obvious approach would be to just make XDP take the lock of the
network stack's TX queue corresponding to the ring it's about to enqueue
in.

For XDP_REDIRECT, this is quite straightforward, a lock at the beginning
and end of enetc_xdp_xmit() should do the trick.

But for XDP_TX, it's a bit more complicated. For one, we do TX batching
all by ourselves for frames with the XDP_TX verdict. This is something
we would like to keep the way it is, for performance reasons. But
batching means that the network stack's lock should be kept from the
first enqueued XDP_TX frame and until we ring the doorbell. That is
mostly fine, except for cases when in the same NAPI loop we have mixed
XDP_TX and XDP_REDIRECT frames. So if enetc_xdp_xmit() gets called while
we are holding the lock from the RX NAPI, then bam, deadlock. The naive
answer could be 'just flush the XDP_TX frames first, then release the
network stack's TX queue lock, then call xdp_do_flush_map()'. But even
xdp_do_redirect() is capable of flushing the batched XDP_REDIRECT
frames, so unless we unlock/relock the TX queue around xdp_do_redirect(),
there simply isn't any clean way to protect XDP_TX from concurrent
network stack .ndo_start_xmit() on another CPU.

So we need to take a different approach, and that is to reserve two
rings for the sole use of XDP. We leave TX rings
0..ndev->real_num_tx_queues-1 to be handled by the network stack, and we
pick them from the end of the priv->tx_ring array.

We make an effort to keep the mapping done by enetc_alloc_msix() which
decides which CPU handles the TX completions of which TX ring in its
NAPI poll. So the XDP TX ring of CPU 0 is handled by TX ring 6, and the
XDP TX ring of CPU 1 is handled by TX ring 7.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: enetc: increase TX ring size

Now that commit d6a2829e82cf ("net: enetc: increase RX ring default
size") has increased the RX ring size, it is quite easy to congest the
TX rings when the traffic

net: enetc: increase TX ring size

Now that commit d6a2829e82cf ("net: enetc: increase RX ring default
size") has increased the RX ring size, it is quite easy to congest the
TX rings when the traffic is predominantly XDP_TX, as the RX ring is
quite a bit larger than the TX one.

Since we bit the bullet and did the expensive thing already (larger RX
rings consume more memory pages), it seems quite foolish to keep the TX
rings small. So make them equally sized with TX.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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enetc: support PTP Sync packet one-step timestamping

This patch is to add support for PTP Sync packet one-step timestamping.
Since ENETC single-step register has to be configured dynamically per
pac

enetc: support PTP Sync packet one-step timestamping

This patch is to add support for PTP Sync packet one-step timestamping.
Since ENETC single-step register has to be configured dynamically per
packet for correctionField offeset and UDP checksum update, current
one-step timestamping packet has to be sent only when the last one
completes transmitting on hardware. So, on the TX, this patch handles
one-step timestamping packet as below:

- Trasmit packet immediately if no other one in transfer, or queue to
skb queue if there is already one in transfer.
The test_and_set_bit_lock() is used here to lock and check state.
- Start a work when complete transfer on hardware, to release the bit
lock and to send one skb in skb queue if has.

And the configuration for one-step timestamping on ENETC before
transmitting is,

- Set one-step timestamping flag in extension BD.
- Write 30 bits current timestamp in tstamp field of extension BD.
- Update PTP Sync packet originTimestamp field with current timestamp.
- Configure single-step register for correctionField offeset and UDP
checksum update.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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