Current struct pernet_operations exit() handlers are highly
discouraged to call synchronize_rcu().

There are cases where we need them, and exit_batch() does
not help the common case where a single netns is dismantled.

This patch leverages the existing synchronize_rcu() call
in cleanup_net()

Calling optional ->pre_exit() method before ->exit() or
->exit_batch() allows to benefit from a single synchronize_rcu()
call.

Note that the synchronize_rcu() calls added in this patch
are only in error paths or slow paths.

Tested:

$ time for i in {1..1000}; do unshare -n /bin/false;done

real	0m2.612s
user	0m0.171s
sys	0m2.216s
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jesper Dangaard Brouer says:

====================
xdp: page_pool fixes and in-flight accounting

This patchset fix page_pool API and users, such that drivers can use it for
DMA-mapping. A number of places exist, where the DMA-mapping would not get
released/unmapped, all these are fixed. This occurs e.g. when an xdp_frame
gets converted to an SKB. As network stack doesn't have any callback for XDP
memory models.

The patchset also address a shutdown race-condition. Today removing a XDP
memory model, based on page_pool, is only delayed one RCU grace period. This
isn't enough as redirected xdp_frames can still be in-flight on different
queues (remote driver TX, cpumap or veth).

We stress that when drivers use page_pool for DMA-mapping, then they MUST
use one packet per page. This might change in the future, but more work lies
ahead, before we can lift this restriction.

This patchset change the page_pool API to be more strict, as in-flight page
accounting is added.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

For DMA mapping use-case the page_pool keeps a pointer
to the struct device, which is used in DMA map/unmap calls.

For our in-flight handling, we also need to make sure that
the struct device have not disappeared.  This is assured
via using get_device/put_device API.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reported-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The xdp tracepoints for mem id disconnect don't carry information about, why
it was not safe_to_remove.  The tracepoint page_pool:page_pool_inflight in
this patch can be used for extract this info for further debugging.

This patchset also adds tracepoint for the pages_state_* release/hold
transitions, including a pointer to the page.  This can be used for stats
about in-flight pages, or used to debug page leakage via keeping track of
page pointer and combining this with kprobe for __put_page().
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

These tracepoints make it easier to troubleshoot XDP mem id disconnect.

The xdp:mem_disconnect tracepoint cannot be replaced via kprobe. It is
placed at the last stable place for the pointer to struct xdp_mem_allocator,
just before it's scheduled for RCU removal. It also extract info on
'safe_to_remove' and 'force'.

Detailed info about in-flight pages is not available at this layer. The next
patch will added tracepoints needed at the page_pool layer for this.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If bugs exists or are introduced later e.g. by drivers misusing the API,
then we want to warn about the issue, such that developer notice. This patch
will generate a bit of noise in form of periodic pr_warn every 30 seconds.

It is not nice to have this stall warning running forever. Thus, this patch
will (after 120 attempts) force disconnect the mem id (from the rhashtable)
and free the page_pool object. This will cause fallback to the put_page() as
before, which only potentially leak DMA-mappings, if objects are really
stuck for this long. In that unlikely case, a WARN_ONCE should show us the
call stack.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is needed before we can allow drivers to use page_pool for
DMA-mappings. Today with page_pool and XDP return API, it is possible to
remove the page_pool object (from rhashtable), while there are still
in-flight packet-pages. This is safely handled via RCU and failed lookups in
__xdp_return() fallback to call put_page(), when page_pool object is gone.
In-case page is still DMA mapped, this will result in page note getting
correctly DMA unmapped.

To solve this, the page_pool is extended with tracking in-flight pages. And
XDP disconnect system queries page_pool and waits, via workqueue, for all
in-flight pages to be returned.

To avoid killing performance when tracking in-flight pages, the implement
use two (unsigned) counters, that in placed on different cache-lines, and
can be used to deduct in-flight packets. This is done by mapping the
unsigned "sequence" counters onto signed Two's complement arithmetic
operations. This is e.g. used by kernel's time_after macros, described in
kernel commit 1ba3aab3 and 5a581b36, and also explained in RFC1982.

The trick is these two incrementing counters only need to be read and
compared, when checking if it's safe to free the page_pool structure. Which
will only happen when driver have disconnected RX/alloc side. Thus, on a
non-fast-path.

It is chosen that page_pool tracking is also enabled for the non-DMA
use-case, as this can be used for statistics later.

After this patch, using page_pool requires more strict resource "release",
e.g. via page_pool_release_page() that was introduced in this patchset, and
previous patches implement/fix this more strict requirement.

Drivers no-longer call page_pool_destroy(). Drivers already call
xdp_rxq_info_unreg() which call xdp_rxq_info_unreg_mem_model(), which will
attempt to disconnect the mem id, and if attempt fails schedule the
disconnect for later via delayed workqueue.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The mlx5 driver is using page_pool, but not for DMA-mapping (currently), and
is a little too relaxed about returning or releasing page resources, as it
is not strictly necessary, when not using DMA-mappings.

As this patchset is working towards tracking page_pool resources, to know
about in-flight frames on shutdown. Then fix places where mlx5 leak
page_pool resource.

In case of dma_mapping_error, then recycle into page_pool.

In mlx5e_free_rq() moved the page_pool_destroy() call to after the
mlx5e_page_release() calls, as it is more correct.

In mlx5e_page_release() when no recycle was requested, then release page
from the page_pool, via page_pool_release_page().
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In case driver fails to register the page_pool with XDP return API (via
xdp_rxq_info_reg_mem_model()), then the driver can free the page_pool
resources more directly than calling page_pool_destroy(), which does a
unnecessarily RCU free procedure.

This patch is preparing for removing page_pool_destroy(), from driver
invocation.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Like cpumap use xdp_release_frame() when an xdp_frame got
converted into an SKB and send towars the network stack.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When converting an xdp_frame into an SKB, and sending this into the network
stack, then the underlying XDP memory model need to release associated
resources, because the network stack don't have callbacks for XDP memory
models.  The only memory model that needs this is page_pool, when a driver
use the DMA-mapping feature.

Introduce page_pool_release_page(), which basically does the same as
page_pool_unmap_page(). Add xdp_release_frame() as the XDP memory model
interface for calling it, if the memory model match MEM_TYPE_PAGE_POOL, to
save the function call overhead for others. Have cpumap call
xdp_release_frame() before xdp_scrub_frame().
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix error handling case, where inserting ID with rhashtable_insert_slow
fails in xdp_rxq_info_reg_mem_model, which leads to never releasing the IDA
ID, as the lookup in xdp_rxq_info_unreg_mem_model fails and thus
ida_simple_remove() is never called.

Fix by releasing ID via ida_simple_remove(), and mark xdp_rxq->mem.id with
zero, which is already checked in xdp_rxq_info_unreg_mem_model().
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

On a previous patch dma addr was stored in 'struct page'.
Use that to unmap DMA addresses used by network drivers
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On a previous patch dma addr was stored in 'struct page'.
Use that to retrieve DMA addresses used by network drivers
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netsec_process_rx was running in a loop trying to process as many packets
as possible before re-enabling interrupts. With the recent DMA changes
this is not needed anymore as we manage to consume all the budget without
looping over the function.
Since it has no performance penalty let's remove that and simplify the Rx
path a bit
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since we changed the Tx ring handling and now depends on bit31 to figure
out the owner of the descriptor, we should initialize this every time
the device goes down-up instead of doing it once on driver init. If the
value is not correctly initialized the device won't have any available
descriptors

Changes since v1:
- Typo fixes

Fixes: 35e07d23 ("net: socionext: remove mmio reads on Tx")
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The comment is correct, but the code ends up moving the bits four
places too far, into the VTUOp field.

Fixes: bec8e572 (net: dsa: mv88e6xxx: implement vtu_getnext and vtu_loadpurge for mv88e6250)
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use _BITUL() instead.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Implement flower ingress device matching offload

Jiri says:

In case of using shared block, user might find it handy to be able to insert
filters to match on particular ingress device. This patchset exposes the
ingress ifindex through flow_dissector and flow_offload so mlxsw can use it to
push down to HW. See the selftests for examples of usage.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Extend tc_flower to test plain ingress device matching and also
tc_shblock to test ingress device matching on shared block.
Add new tc_flower_router.sh where ingress device matching on egress
(after routing) is done.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Benefit from the previously extended flow_dissector infrastructure and
offload matching on ingress port.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the size of the SRC_SYS_PORT element to be 16.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RX_ACL_SYSTEM_PORT is 8 bit but SRC_SYS_PORT is 16 bits. Internally,
SRC_SYS_PORT is used to carry the value. Relax the checker in case of
RX_ACL_SYSTEM_PORT and allow different size.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RX_ACL_SYSTEM_PORT is equal to SRC_SYS_PORT - 1. So before write to
block we need to adjust the key value. Introduce new "EXT" helper to
implement this.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Implement support for previously added flow dissector meta key.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use previously introduced infra to obtain and store ingress ifindex
instead doing it locally.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add new key meta that contains ingress ifindex value and add a function
to dissect this from skb. The key and function is prepared to cover
other potential skb metadata values dissection.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Function mlx5_devlink_alloc is missing a void argument, add it
to clean up the non-ANSI function declaration.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Maxime Chevallier says:

====================
net: mvpp2: cls: Allow steering based on vlan tag

The PPv2 classifier can perform flow steering based on keys extracted
from the VLAN tag. This series adds support for using the vlan id and
the vlan prio as keys, using the ethtool interface.

Patch 1 is a preparatory patch that prevent false-positive matches,
using a dedicated lookup id for the RSS C2 lookup.

Patch 2 allows to separate the flows based on the header fields they
contain. The main goal is to be able to separate tagged traffic from
untagged traffic for flow steering, just as we already do for RSS.

Patch 3 solves an issue we have when extracting fields that aren't full
bytes, such as the vlan tag which is 12 bits wide, or the priority which
is 3 bits wide.

Finally, patch 4 adds support for steering based on both vlan id and
priority, extracted from the outermost tag.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This commit allows using the vlan Id and priority as parts of the key
for classification offload. These fields are extracted from the
outermost tag, if multiple tags are present.

Vlan Id and priority are considered as 2 different fields by the
classifier, however the fields are both appended in the Header Extracted
Key in the same layout as they are found in the tags. This means that
when steering only based on the prio, a 16-bit slot is still taken in
the HEK.

The classifier doesn't allow extracting the DEI bit from the tag, so we
explicitly prevent user from using this bit in the key.

This commit adds the vlan priotity as a compatible HEK field for
tagged traffic, meaning that we limit the possibility of extracting this
field only to the flows that contain tagged traffic.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The C2 TCAM used for classification uses a key (Header Extracted Key)
built by concatenating several fields extracted from the packet header.

After a lot of trial-and-error and some guess work, it seems the HEK is
right justified, with the first fields being stored in the MSB, then
concatenated up until the LSB.

Until now, this doesn't cause any issue since all HEK fields we use are
full bytes. However this is an issue for the upcoming VLAN id and pri
extraction, which aren't full bytes.

Rework the way we built that TCAM key, by changing the order in which we
append the fields.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The way we currently handle classification offload and RSS is by having
dedicated lookup sequences in the flow table, each being selected
depending on several fields being present in the packet header.

We need to make sure the classification operation we want to perform can
be done in each flow we want to insert it into. As an example,
classifying on VLAN tag can only be done on flows used for tagged
traffic.

This commit makes sure we don't insert rules in flows we aren't
compatible with.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When performing a TCAM lookup in the C2 engine, it's possible that
multiple entries match the packet. To make sure the correct entry match
when performing a lookup, the Flow Table can set a lookup type, which
will be used in the TCAM lookup, thus preventing such false-positives.

We need to make sure the RSS match doesn't interfere with other
classification lookups, hence we use a dedicated lookup_type for it.
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Yash Shah says:

====================
Add macb support for SiFive FU540-C000

On FU540, the management IP block is tightly coupled with the Cadence
MACB IP block. It manages many of the boundary signals from the MACB IP
This patchset controls the tx_clk input signal to the MACB IP. It
switches between the local TX clock (125MHz) and PHY TX clocks. This
is necessary to toggle between 1Gb and 100/10Mb speeds.

Future patches may add support for monitoring or controlling other IP
boundary signals.

This patchset is mostly based on work done by
Wesley Terpstra <wesley@sifive.com>

This patchset is based on Linux v5.2-rc1 and tested on HiFive Unleashed
board with additional board related patches needed for testing can be
found at dev/yashs/ethernet_v3 branch of:
https://github.com/yashshah7/riscv-linux.git

Change History:
V3:
- Revert "MACB_SIFIVE_FU540" config changes in Kconfig and driver code.
  The driver does not depend on SiFive GPIO driver.

V2:
- Change compatible string from "cdns,fu540-macb" to "sifive,fu540-macb"
- Add "MACB_SIFIVE_FU540" in Kconfig to support SiFive FU540 in macb
  driver. This is needed because on FU540, the macb driver depends on
  SiFive GPIO driver.
- Avoid writing the result of a comparison to a register.
- Fix the issue of probe fail on reloading the module reported by:
  Andreas Schwab <schwab@suse.de>
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The management IP block is tightly coupled with the Cadence MACB IP
block on the FU540, and manages many of the boundary signals from the
MACB IP. This patch only controls the tx_clk input signal to the MACB
IP. Future patches may add support for monitoring or controlling other
IP boundary signals.
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the compatibility string documentation for SiFive FU540-C0000
interface.
On the FU540, this driver also needs to read and write registers in a
management IP block that monitors or drives boundary signals for the
GEMGXL IP block that are not directly mapped to GEMGXL registers.
Therefore, add additional range to "reg" property for SiFive GEMGXL
management IP registers.
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Xue Chaojing says:

====================
hinic: add rss support and rss parameters configuration

This series add rss support for HINIC driver and implement the ethtool
interface related to rss parameter configuration. user can use ethtool
configure rss parameters or show rss parameters.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds support rss parameters with ethtool,
user can change hash key, hash indirection table, hash
function by ethtool -X, and show rss parameters by ethtool -x.
Signed-off-by: Xue Chaojing <xuechaojing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch moves ethtool code from hinic_main.c to hinic_ethtool.c
Signed-off-by: Xue Chaojing <xuechaojing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds rss support for the HINIC driver.
Signed-off-by: Xue Chaojing <xuechaojing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>