Instead of just listing and flushing two cached exceptions, create
a relatively big number of them, and count how many are listed. Single
netlink dump messages contain approximately 25 entries each, and this
way we can make sure the partial dump tracking mechanism is working
properly.

While at it, also ensure that no cached routes can be listed after
flush, and remove 'sleep 1' calls, they are not actually needed.

v7: No changes

v6:
  - Merge this patch into series including fix, as it's also targeted
    for net-next. No actual changes
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This test checks that route exceptions can be successfully listed and
flushed using ip -6 route {list,flush} cache.

v7: No changes

v6:
  - Merge this patch into series including fix, as it's also targeted
    for net-next
  - Drop left-over print of 'ip route list cache | wc -l'
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When we perform an inexact match on FIB nodes via fib6_locate_1(), longer
prefixes will be preferred to shorter ones. However, it might happen that
a node, with higher fn_bit value than some other, has no valid routing
information.

In this case, we'll pick that node, but it will be discarded by the check
on RTN_RTINFO in fib6_locate(), and we might miss nodes with valid routing
information but with lower fn_bit value.

This is apparent when a routing exception is created for a default route:
 # ip -6 route list
 fc00:1::/64 dev veth_A-R1 proto kernel metric 256 pref medium
 fc00:2::/64 dev veth_A-R2 proto kernel metric 256 pref medium
 fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 pref medium
 fe80::/64 dev veth_A-R1 proto kernel metric 256 pref medium
 fe80::/64 dev veth_A-R2 proto kernel metric 256 pref medium
 default via fc00:1::2 dev veth_A-R1 metric 1024 pref medium
 # ip -6 route list cache
 fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 expires 593sec mtu 1500 pref medium
 fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 593sec mtu 1500 pref medium
 # ip -6 route flush cache    # node for default route is discarded
 Failed to send flush request: No such process
 # ip -6 route list cache
 fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 586sec mtu 1500 pref medium

Check right away if the node has a RTN_RTINFO flag, before replacing the
'prev' pointer, that indicates the longest matching prefix found so far.

Fixes: 38fbeeee ("ipv6: prepare fib6_locate() for exception table")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 2b760fcf ("ipv6: hook up exception table to store dst
cache"), route exceptions reside in a separate hash table, and won't be
found by walking the FIB, so they won't be dumped to userspace on a
RTM_GETROUTE message.

This causes 'ip -6 route list cache' and 'ip -6 route flush cache' to
have no function anymore:

 # ip -6 route get fc00:3::1
 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 539sec mtu 1400 pref medium
 # ip -6 route get fc00:4::1
 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 536sec mtu 1500 pref medium
 # ip -6 route list cache
 # ip -6 route flush cache
 # ip -6 route get fc00:3::1
 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 520sec mtu 1400 pref medium
 # ip -6 route get fc00:4::1
 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 519sec mtu 1500 pref medium

because iproute2 lists cached routes using RTM_GETROUTE, and flushes them
by listing all the routes, and deleting them with RTM_DELROUTE one by one.

If cached routes are requested using the RTM_F_CLONED flag together with
strict checking, or if no strict checking is requested (and hence we can't
consistently apply filters), look up exceptions in the hash table
associated with the current fib6_info in rt6_dump_route(), and, if present
and not expired, add them to the dump.

We might be unable to dump all the entries for a given node in a single
message, so keep track of how many entries were handled for the current
node in fib6_walker, and skip that amount in case we start from the same
partially dumped node.

When a partial dump restarts, as the starting node might change when
'sernum' changes, we have no guarantee that we need to skip the same
amount of in-node entries. Therefore, we need two counters, and we need to
zero the in-node counter if the node from which the dump is resumed
differs.

Note that, with the current version of iproute2, this only fixes the
'ip -6 route list cache': on a flush command, iproute2 doesn't pass
RTM_F_CLONED and, due to this inconsistency, 'ip -6 route flush cache' is
still unable to fetch the routes to be flushed. This will be addressed in
a patch for iproute2.

To flush cached routes, a procfs entry could be introduced instead: that's
how it works for IPv4. We already have a rt6_flush_exception() function
ready to be wired to it. However, this would not solve the issue for
listing.

Versions of iproute2 and kernel tested:

                    iproute2
kernel             4.14.0   4.15.0   4.19.0   5.0.0   5.1.0    5.1.0, patched
 3.18    list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.4     list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.9     list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.14    list        +        +        +        +       +            +
         flush       +        +        +        +       +            +
 4.15    list
         flush
 4.19    list
         flush
 5.0     list
         flush
 5.1     list
         flush
 with    list        +        +        +        +       +            +
 fix     flush       +        +        +                             +

v7:
  - Explain usage of "skip" counters in commit message (suggested by
    David Ahern)

v6:
  - Rebase onto net-next, use recently introduced nexthop walker
  - Make rt6_nh_dump_exceptions() a separate function (suggested by David
    Ahern)

v5:
  - Use dump_routes and dump_exceptions from filter, ignore NLM_F_MATCH,
    update test results (flushing works with iproute2 < 5.0.0 now)

v4:
  - Split NLM_F_MATCH and strict check handling in separate patches
  - Filter routes using RTM_F_CLONED: if it's not set, only return
    non-cached routes, and if it's set, only return cached routes:
    change requested by David Ahern and Martin Lau. This implies that
    iproute2 needs a separate patch to be able to flush IPv6 cached
    routes. This is not ideal because we can't fix the breakage caused
    by 2b760fcf entirely in kernel. However, two years have passed
    since then, and this makes it more tolerable

v3:
  - More descriptive comment about expired exceptions in rt6_dump_route()
  - Swap return values of rt6_dump_route() (suggested by Martin Lau)
  - Don't zero skip_in_node in case we don't dump anything in a given pass
    (also suggested by Martin Lau)
  - Remove check on RTM_F_CLONED altogether: in the current UAPI semantic,
    it's just a flag to indicate the route was cloned, not to filter on
    routes

v2: Add tracking of number of entries to be skipped in current node after
    a partial dump. As we restart from the same node, if not all the
    exceptions for a given node fit in a single message, the dump will
    not terminate, as suggested by Martin Lau. This is a concrete
    possibility, setting up a big number of exceptions for the same route
    actually causes the issue, suggested by David Ahern.
Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: 2b760fcf ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the next patch, we are going to add optional dump of exceptions to
rt6_dump_route().

Change the return code of rt6_dump_route() to accomodate partial node
dumps: we might dump multiple routes per node, and might be able to dump
only a given number of them, so fib6_dump_node() will need to know how
many routes have been dumped on partial dump, to restart the dump from the
point where it was interrupted.

Note that fib6_dump_node() is the only caller and already handles all
non-negative return codes as success: those become -1 to signal that we're
done with the node. If we fail, return 0, as we were unable to dump the
single route in the node, but we're not done with it.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If fc_nh_id isn't set, we shouldn't try to match against it. This
actually matters just for the RTF_CACHE below (where this case is
already handled): if iproute2 gets a route exception and tries to
delete it, it won't reference it by fc_nh_id, even if a nexthop
object might be associated to the originating route.

Fixes: 5b98324e ("ipv6: Allow routes to use nexthop objects")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 08e814c9: as we
are preparing to fix listing and dumping of IPv6 cached routes, we
need to allow RTM_F_CLONED as a flag to match routes against while
dumping them.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 4895c771 ("ipv4: Add FIB nexthop exceptions."), cached
exception routes are stored as a separate entity, so they are not dumped
on a FIB dump, even if the RTM_F_CLONED flag is passed.

This implies that the command 'ip route list cache' doesn't return any
result anymore.

If the RTM_F_CLONED is passed, and strict checking requested, retrieve
nexthop exception routes and dump them. If no strict checking is
requested, filtering can't be performed consistently: dump everything in
that case.

With this, we need to add an argument to the netlink callback in order to
track how many entries were already dumped for the last leaf included in
a partial netlink dump.

A single additional argument is sufficient, even if we traverse logically
nested structures (nexthop objects, hash table buckets, bucket chains): it
doesn't matter if we stop in the middle of any of those, because they are
always traversed the same way. As an example, s_i values in [], s_fa
values in ():

  node (fa) #1 [1]
    nexthop #1
    bucket #1 -> #0 in chain (1)
    bucket #2 -> #0 in chain (2) -> #1 in chain (3) -> #2 in chain (4)
    bucket #3 -> #0 in chain (5) -> #1 in chain (6)

    nexthop #2
    bucket #1 -> #0 in chain (7) -> #1 in chain (8)
    bucket #2 -> #0 in chain (9)
  --
  node (fa) #2 [2]
    nexthop #1
    bucket #1 -> #0 in chain (1) -> #1 in chain (2)
    bucket #2 -> #0 in chain (3)

it doesn't matter if we stop at (3), (4), (7) for "node #1", or at (2)
for "node #2": walking flattens all that.

It would even be possible to drop the distinction between the in-tree
(s_i) and in-node (s_fa) counter, but a further improvement might
advise against this. This is only as accurate as the existing tracking
mechanism for leaves: if a partial dump is restarted after exceptions
are removed or expired, we might skip some non-dumped entries.

To improve this, we could attach a 'sernum' attribute (similar to the
one used for IPv6) to nexthop entities, and bump this counter whenever
exceptions change: having a distinction between the two counters would
make this more convenient.

Listing of exception routes (modified routes pre-3.5) was tested against
these versions of kernel and iproute2:

                    iproute2
kernel         4.14.0   4.15.0   4.19.0   5.0.0   5.1.0
 3.5-rc4         +        +        +        +       +
 4.4
 4.9
 4.14
 4.15
 4.19
 5.0
 5.1
 fixed           +        +        +        +       +

v7:
   - Move loop over nexthop objects to route.c, and pass struct fib_info
     and table ID to it, not a struct fib_alias (suggested by David Ahern)
   - While at it, note that the NULL check on fa->fa_info is redundant,
     and the check on RTNH_F_DEAD is also not consistent with what's done
     with regular route listing: just keep it for nhc_flags
   - Rename entry point function for dumping exceptions to
     fib_dump_info_fnhe(), and rearrange arguments for consistency with
     fib_dump_info()
   - Rename fnhe_dump_buckets() to fnhe_dump_bucket() and make it handle
     one bucket at a time
   - Expand commit message to describe why we can have a single "skip"
     counter for all exceptions stored in bucket chains in nexthop objects
     (suggested by David Ahern)

v6:
   - Rebased onto net-next
   - Loop over nexthop paths too. Move loop over fnhe buckets to route.c,
     avoids need to export rt_fill_info() and to touch exceptions from
     fib_trie.c. Pass NULL as flow to rt_fill_info(), it now allows that
     (suggested by David Ahern)

Fixes: 4895c771 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the next patch, we're going to use rt_fill_info() to dump exception
routes upon RTM_GETROUTE with NLM_F_ROOT, meaning userspace is requesting
a dump and not a specific route selection, which in turn implies the input
interface is not relevant. Update rt_fill_info() to handle a NULL
flowinfo.

v7: If fl4 is NULL, explicitly set r->rtm_tos to 0: it's not initialised
    otherwise (spotted by David Ahern)

v6: New patch
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This functionally reverts the check introduced by commit
e8ba330a ("rtnetlink: Update fib dumps for strict data checking")
as modified by commit e4e92fb1 ("net/ipv4: Bail early if user only
wants prefix entries").

As we are preparing to fix listing of IPv4 cached routes, we need to
give userspace a way to request them.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The following patches add back the ability to dump IPv4 and IPv6 exception
routes, and we need to allow selection of regular routes or exceptions.

Use RTM_F_CLONED as filter to decide whether to dump routes or exceptions:
iproute2 passes it in dump requests (except for IPv6 cache flush requests,
this will be fixed in iproute2) and this used to work as long as
exceptions were stored directly in the FIB, for both IPv4 and IPv6.

Caveat: if strict checking is not requested (that is, if the dump request
doesn't go through ip_valid_fib_dump_req()), we can't filter on protocol,
tables or route types.

In this case, filtering on RTM_F_CLONED would be inconsistent: we would
fix 'ip route list cache' by returning exception routes and at the same
time introduce another bug in case another selector is present, e.g. on
'ip route list cache table main' we would return all exception routes,
without filtering on tables.

Keep this consistent by applying no filters at all, and dumping both
routes and exceptions, if strict checking is not requested. iproute2
currently filters results anyway, and no unwanted results will be
presented to the user. The kernel will just dump more data than needed.

v7: No changes

v6: Rebase onto net-next, no changes

v5: New patch: add dump_routes and dump_exceptions flags in filter and
    simply clear the unwanted one if strict checking is enabled, don't
    ignore NLM_F_MATCH and don't set filter_set if NLM_F_MATCH is set.
    Skip filtering altogether if no strict checking is requested:
    selecting routes or exceptions only would be inconsistent with the
    fact we can't filter on tables.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch updates the macb driver to use NAPI GRO helpers when
receiving SKBs. This improves performances.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use NAPI_POLL_WEIGHT, the default NAPI poll() weight instead of
redefining our own value (which turns out to be 64 as well).
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Shijie Luo says:

====================
ipv4: fix bugs when enable route_localnet

When enable route_localnet, route of the 127/8 address is enabled.
But in some situations like arp_announce=2, ARP requests or reply
work abnormally.

This patchset fix some bugs when enable route_localnet.

Change History:
V2:
- Change a single patch to a patchset.
- Add bug fix for arp_ignore = 3.
- Add a couple of test for enabling route_localnet in selftests.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a simple scripts to exercise several situations when enable
route_localnet.
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Zhiqiang liu <liuzhiqiang26@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When arp_ignore=3, the NIC won't reply for scope host addresses, but
if enable route_locanet, we need to reply ip address with head 127 and
scope RT_SCOPE_HOST.

Fixes: d0daebc3 ("ipv4: Add interface option to enable routing of 127.0.0.0/8")
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Suppose we have two interfaces eth0 and eth1 in two hosts, follow
the same steps in the two hosts:
 # sysctl -w net.ipv4.conf.eth1.route_localnet=1
 # sysctl -w net.ipv4.conf.eth1.arp_announce=2
 # ip route del 127.0.0.0/8 dev lo table local
and then set ip to eth1 in host1 like:
 # ifconfig eth1 127.25.3.4/24
set ip to eth2 in host2 and ping host1:
 # ifconfig eth1 127.25.3.14/24
 # ping -I eth1 127.25.3.4
Well, host2 cannot connect to host1.

When set a ip address with head 127, the scope of the address defaults
to RT_SCOPE_HOST. In this situation, host2 will use arp_solicit() to
send a arp request for the mac address of host1 with ip
address 127.25.3.14. When arp_announce=2, inet_select_addr() cannot
select a correct saddr with condition ifa->ifa_scope > scope, because
ifa_scope is RT_SCOPE_HOST and scope is RT_SCOPE_LINK. Then,
inet_select_addr() will go to no_in_dev to lookup all interfaces to find
a primary ip and finally get the primary ip of eth0.

Here I add a localnet_scope defaults to RT_SCOPE_HOST, and when
route_localnet is enabled, this value changes to RT_SCOPE_LINK to make
inet_select_addr() find a correct primary ip as saddr of arp request.

Fixes: d0daebc3 ("ipv4: Add interface option to enable routing of 127.0.0.0/8")
Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: Zhiqiang Liu <liuzhiqiang26@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tipc_nl_compat_bearer_set() is only called by tipc_nl_compat_link_set()
which already does the check for msg->req check, so remove it from
tipc_nl_compat_bearer_set(), and do the same in tipc_nl_compat_media_set().
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ido Schimmel says:

====================
mlxsw: Thermal and hwmon extensions

This patchset from Vadim includes various enhancements to thermal and
hwmon code in mlxsw.

Patch #1 adds a thermal zone for each inter-connect device (gearbox).
These devices are present in SN3800 systems and code to expose their
temperature via hwmon was added in commit 2e265a8b ("mlxsw: core:
Extend hwmon interface with inter-connect temperature attributes").

Currently, there are multiple thermal zones in mlxsw and only a few
cooling devices. Patch #2 detects the hottest thermal zone and the
cooling devices are switched to follow its trends. RFC was sent last
month [1].

Patch #3 allows to read and report negative temperature of the sensors
mlxsw exposes via hwmon and thermal subsystems.

v2 (Andrew Lunn):
* In patch #3, replace '%u' with '%d' in mlxsw_hwmon_module_temp_show()

[1] https://patchwork.ozlabs.org/patch/1107161/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Extend macros MLXSW_REG_MTMP_TEMP_TO_MC() to allow support of negative
temperature readout, since chip and others thermal components are
capable of operating within the negative temperature.
With no such support negative temperature will be consider as very high
temperature and it will cause wrong readout and thermal shutdown.
For negative values 2`s complement is used.
Tested in chamber.
Example of chip ambient temperature readout with chamber temperature:
-10 Celsius:
temp1:             -6.0C  (highest =  -5.0C)
-5 Celsius:
temp1:             -1.0C  (highest =  -1.0C)

v2 (Andrew Lunn):
* Replace '%u' with '%d' in mlxsw_hwmon_module_temp_show()
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When multiple sensors are mapped to the same cooling device, the
cooling device should be set according the worst sensor from the
sensors associated with this cooling device.

Provide the hottest thermal zone detection and enforce cooling device
to follow the temperature trends of the hottest zone only.
Prevent competition for the cooling device control from others zones,
by "stable trend" indication. A cooling device will not perform any
actions associated with a zone with a "stable trend".

When other thermal zone is detected as a hottest, a cooling device is
to be switched to following temperature trends of new hottest zone.

Thermal zone score is represented by 32 bits unsigned integer and
calculated according to the next formula:
For T < TZ<t><i>, where t from {normal trip = 0, high trip = 1, hot
trip = 2, critical = 3}:
TZ<i> score = (T + (TZ<t><i> - T) / 2) / (TZ<t><i> - T) * 256 ** j;
Highest thermal zone score s is set as MAX(TZ<i>score);
Following this formula, if TZ<i> is in trip point higher than TZ<k>,
the higher score is to be always assigned to TZ<i>.

For two thermal zones located at the same kind of trip point, the higher
score will be assigned to the zone which is closer to the next trip
point. Thus, the highest score will always be assigned objectively to
the hottest thermal zone.

All the thermal zones initially are to be configured with mode
"enabled" with the "step_wise" governor.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a dedicated thermal zone for each inter-connect device. The
current temperature is obtained from inter-connect temperature sensor
and the default trip points are set to the same values as default ASIC
trip points. These settings could be changed from the user space.
A cooling device (fan) is bound to all inter-connect devices.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix misalignment of policy statement in netlink.c due to automatic
spatch code transformation.

Fixes: 3b0f31f2 ("genetlink: make policy common to family")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: John Rutherford <john.rutherford@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit bfe59032 ("net: ethernet:
ti: cpsw: use cpsw as drv data")changes
the driver data to struct cpsw_common *cpsw. This is done
only in probe/remove but the suspend/resume functions are
still left with struct net_device *ndev. Hence fix both
suspend & resume also to fetch the updated driver data.

Fixes: bfe59032 ("net: ethernet: ti: cpsw: use cpsw as drv data")
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch implement the statistical interface of ethtool, user can use
ethtool -S to show hinic statistics.
Signed-off-by: Xue Chaojing <xuechaojing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Wei Wang says:

====================
ipv6: avoid taking refcnt on dst during route lookup

Ipv6 route lookup code always grabs refcnt on the dst for the caller.
But for certain cases, grabbing refcnt is not always necessary if the
call path is rcu protected and the caller does not cache the dst.
Another issue in the route lookup logic is:
When there are multiple custom rules, we have to do the lookup into
each table associated to each rule individually. And when we can't
find the route in one table, we grab and release refcnt on
net->ipv6.ip6_null_entry before going to the next table.
This operation is completely redundant, and causes false issue because
net->ipv6.ip6_null_entry is a shared object.

This patch set introduces a new flag RT6_LOOKUP_F_DST_NOREF for route
lookup callers to set, to avoid any manipulation on the dst refcnt. And
it converts the major input and output path to use it.

The performance gain is noticable.
I ran synflood tests between 2 hosts under the same switch. Both hosts
have 20G mlx NIC, and 8 tx/rx queues.
Sender sends pure SYN flood with random src IPs and ports using trafgen.
Receiver has a simple TCP listener on the target port.
Both hosts have multiple custom rules:
- For incoming packets, only local table is traversed.
- For outgoing packets, 3 tables are traversed to find the route.
The packet processing rate on the receiver is as follows:
- Before the fix: 3.78Mpps
- After the fix:  5.50Mpps

v2->v3:
- Handled fib6_rule_lookup() when CONFIG_IPV6_MULTIPLE_TABLES is not
  configured in patch 03 (suggested by David Ahern)
- Removed the renaming of l3mdev_link_scope_lookup() in patch 05
  (suggested by David Ahern)
- Moved definition of ip6_route_output_flags() from an inline function
  in /net/ipv6/route.c to net/ipv6/route.c in order to address kbuild
  error in patch 05

v1->v2:
- Added a helper ip6_rt_put_flags() in patch 3 suggested by David Miller
====================
Reviewed-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For tx path, in most cases, we still have to take refcnt on the dst
cause the caller is caching the dst somewhere. But it still is
beneficial to make use of RT6_LOOKUP_F_DST_NOREF flag while doing the
route lookup. It is cause this flag prevents manipulating refcnt on
net->ipv6.ip6_null_entry when doing fib6_rule_lookup() to traverse each
routing table. The null_entry is a shared object and constant updates on
it cause false sharing.

We converted the current major lookup function ip6_route_output_flags()
to make use of RT6_LOOKUP_F_DST_NOREF.

Together with the change in the rx path, we see noticable performance
boost:
I ran synflood tests between 2 hosts under the same switch. Both hosts
have 20G mlx NIC, and 8 tx/rx queues.
Sender sends pure SYN flood with random src IPs and ports using trafgen.
Receiver has a simple TCP listener on the target port.
Both hosts have multiple custom rules:
- For incoming packets, only local table is traversed.
- For outgoing packets, 3 tables are traversed to find the route.
The packet processing rate on the receiver is as follows:
- Before the fix: 3.78Mpps
- After the fix:  5.50Mpps
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip6_route_input() is the key function to do the route lookup in the
rx data path. All the callers to this function are already holding rcu
lock. So it is fairly easy to convert it to not take refcnt on the dst:
We pass in flag RT6_LOOKUP_F_DST_NOREF and do skb_dst_set_noref().
This saves a few atomic inc or dec operations and should boost
performance overall.
This also makes the logic more aligned with v4.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch specifically converts the rule lookup logic to honor this
flag and not release refcnt when traversing each rule and calling
lookup() on each routing table.
Similar to previous patch, we also need some special handling of dst
entries in uncached list because there is always 1 refcnt taken for them
even if RT6_LOOKUP_F_DST_NOREF flag is set.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Initialize rt6->rt6i_uncached on the following pre-allocated dsts:
net->ipv6.ip6_null_entry
net->ipv6.ip6_prohibit_entry
net->ipv6.ip6_blk_hole_entry

This is a preparation patch for later commits to be able to distinguish
dst entries in uncached list by doing:
!list_empty(rt6->rt6i_uncached)
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This new flag is to instruct the route lookup function to not take
refcnt on the dst entry. The user which does route lookup with this flag
must properly use rcu protection.
ip6_pol_route() is the major route lookup function for both tx and rx
path.
In this function:
Do not take refcnt on dst if RT6_LOOKUP_F_DST_NOREF flag is set, and
directly return the route entry. The caller should be holding rcu lock
when using this flag, and decide whether to take refcnt or not.

One note on the dst cache in the uncached_list:
As uncached_list does not consume refcnt, one refcnt is always returned
back to the caller even if RT6_LOOKUP_F_DST_NOREF flag is set.
Uncached dst is only possible in the output path. So in such call path,
caller MUST check if the dst is in the uncached_list before assuming
that there is no refcnt taken on the returned dst.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There seems to be some confusion surrounding three PHY interface modes,
specifically 1000BASE-X, 2500BASE-X and SGMII.  Add some documentation
to phylib detailing precisely what these interface modes refer to.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The linux-next commit "inet: fix various use-after-free in defrags
units" [1] introduced compilation warnings,

./include/net/inet_frag.h:117:1: warning: 'inline' is not at beginning
of declaration [-Wold-style-declaration]
 static void inline fqdir_pre_exit(struct fqdir *fqdir)
 ^~~~~~
In file included from ./include/net/netns/ipv4.h:10,
                 from ./include/net/net_namespace.h:20,
                 from ./include/linux/netdevice.h:38,
                 from ./include/linux/icmpv6.h:13,
                 from ./include/linux/ipv6.h:86,
                 from ./include/net/ipv6.h:12,
                 from ./include/rdma/ib_verbs.h:51,
                 from ./include/linux/mlx5/device.h:37,
                 from ./include/linux/mlx5/driver.h:51,
                 from
drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c:37:

[1] https://lore.kernel.org/netdev/20190618180900.88939-3-edumazet@google.com/Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is a no-op that simply moves all locking and unlocking of
->reg_lock into trivial helpers. I did that to be able to easily add
some ad hoc instrumentation to those helpers to get some information
on contention and hold times of the mutex. Perhaps others want to do
something similar at some point, so this frees them from doing the
'sed -i' yoga, and have a much smaller 'git diff' while fiddling.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The current code of create_queues_with_size_backoff() allows the ring size
to become as small as ENA_MIN_RING_SIZE/2. This is a bug since we don't
want the queue ring to be smaller than ENA_MIN_RING_SIZE

In this commit we change the loop's termination condition to look at the
queue size of the next iteration instead of that of the current one,
so that the minimal queue size again becomes ENA_MIN_RING_SIZE.

Fixes: eece4d2a ("net: ena: add ethtool function for changing io queue sizes")
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently pointer hwdev is dereferenced when assigning hwif before
hwdev is null checked.  Fix this by only derefencing hwdev after the
null check.

Addresses-Coverity: ("Dereference before null check")
Fixes: 4fdc51bb ("hinic: add support for rss parameters with ethtool")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

René van Dorst says:

====================
net: mediatek: Add MT7621 TRGMII mode support

Like many other mediatek SOCs, the MT7621 SOC and the internal MT7530
switch both supports TRGMII mode. MT7621 TRGMII speed is fix 1200MBit.

v1->v2:
 - Fix breakage on non MT7621 SOC
 - Support 25MHz and 40MHz XTAL as MT7530 clocksource
====================
Tested-by: "Frank Wunderlich" <frank-w@public-files.de>
Acked-by: Sean Wang <sean.wang@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch add support TRGMII mode for MT7621 internal MT7530 switch.
MT7621 TRGMII has only one fix speed mode of 1200MBit.

Also adding support for mt7530 25MHz and 40MHz crystal clocksource.
Values are based on Banana Pi R2 bsp [1].

Don't change MT7623 registers on a MT7621 device.

[1] https://github.com/BPI-SINOVOIP/BPI-R2-bsp/blob/master/linux-mt/drivers/net/ethernet/mediatek/gsw_mt7623.c#L769Signed-off-by: René van Dorst <opensource@vdorst.com>
Tested-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

MT7621 SOC also supports TRGMII.
TRGMII speed is 1200MBit.
Signed-off-by: René van Dorst <opensource@vdorst.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ops has been iterated to first element when call pre_exit, and
it needs to restore from save_ops, not save ops to save_ops

Fixes: d7d99872 ("netns: add pre_exit method to struct pernet_operations")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>