This patch removed the not needed initialisation from the new_state,
rx_state, tx_state variabled.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch converts the rx_errors and tx_errors from int into bool
values, to reflect their actual meaning.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch changes the declaration of the devtype data to const.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch removes the write only member pdata from the struct
flexcan_priv.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

This patch adds some missing register definitions, which are needed in an
upcoming patch.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Some CAN controllers don't implement a FIFO in hardware, but fill their
mailboxes in a particular order (from lowest to highest or highest to lowest).
This makes problems to read the frames in the correct order from the hardware,
as new frames might be filled into just read (low) mailboxes. This gets worse,
when following new frames are received into not read (higher) mailboxes.

On the bright side some these CAN controllers put a timestamp on each received
CAN frame. This patch adds support to offload CAN frames in interrupt context,
order them by timestamp and then transmitted in a NAPI context.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Some CAN controllers have a usable FIFO already but can still benefit
from off-loading the CAN controller FIFO. The CAN frames of the FIFO are
read and put into a skb queue during interrupt and then transmitted in a
NAPI context.
Signed-off-by: David Jander <david@protonic.nl>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Eric Dumazet says:

====================
net: get rid of __napi_complete()

This patch series removes __napi_complete() calls, in an effort
to make NAPI API simpler and generalize GRO and napi_complete_done()
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

All __napi_complete() callers have been converted to
use the more standard napi_complete_done(),
we can now remove this NAPI method for good.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We plan to remove __napi_complete() soon,
this driver is the last user.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete()

We plan to remove __napi_complete() to reduce NAPI complexity.
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.

Note that rx_lock seems to be useless, NAPI logic should
not need this extra care.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API and get rid of napi_gro_flush()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
4) get rid of baroque code and ease maintenance.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
4) get rid of baroque code and ease maintenance.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
4) get rid of baroque code and ease maintenance.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
4) Eventually get rid of napi_gro_flush() in the future.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use napi_complete_done() instead of __napi_complete() to :

1) Get support of gro_flush_timeout if opt-in
2) Not rearm interrupts for busy-polling users.
3) use standard NAPI API.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

David Ahern says:

====================
net: ipv6: Improve user experience with multipath routes

This series closes a couple of gaps between IPv4 and IPv6 with respect
to multipath routes:

1. IPv4 allows all nexthops of multipath routes to be deleted using just
   the prefix and length; IPv6 only deletes the first nexthop for the
   route if only the prefix and length are given.

2. IPv4 returns multipath routes encoded in the RTA_MULTIPATH attribute.
   IPv6 returns a series of routes with the same prefix and length - one
   for each nexthop. This happens for both dumps and notifications.

IPv6 does accept RTA_MULTIPATH encoded routes, but installs them as a
series of routes.

Patch 1 addresses the first item by allowing IPv6 multipath routes to be
deleted using just the prefix and length. Patch 2 addresses the second
allowing IPv6 multipath routes to be returned encoded in the RTA_MULTIPATH.

Patches 3 and 4 upate the RTM_{NEW,DEL}ROUTE notifications to generate
1 notification with RTA_MULTIPATH where applicable.

Patch 5 prints IPv6 addresses in compressed format when showing route
replace errors. This was noticed testing REPLACE failures.

The end result for multipath routes:
1. Dump
   - RTA_MULTIPATH used for multipath routes

    $ ip -6 ro ls vrf red
    2001:db8:1::/120 dev eth1 proto kernel metric 256  pref medium
    2001:db8:2::/120 dev eth2 proto kernel metric 256  pref medium
    2001:db8:200::/120 metric 1024
	    nexthop via 2001:db8:1::2  dev eth1 weight 1
	    nexthop via 2001:db8:2::2  dev eth2 weight 1
    ...

2. Route Add
   - one notification with RTA_MULTIPATH attribute

    $ ip -6 ro add vrf red 2001:db8:200::/120 nexthop via 2001:db8:1::2 nexthop via 2001:db8:2::2

    $ ip mon route
    2001:db8:200::/120 table red metric 1024
	nexthop via 2001:db8:1::2  dev eth1 weight 1
	nexthop via 2001:db8:2::2  dev eth2 weight 1

2. Route Replace
   - one notification with RTA_MULTIPATH attribute

    $ ip -6 ro replace vrf red 2001:db8:200::/120 nexthop via 2001:db8:1::16 nexthop via 2001:db8:2::16

    $ ip mon route
    Replaced 2001:db8:200::/120 table red metric 1024
	    nexthop via 2001:db8:1::16  dev eth1 weight 1
	    nexthop via 2001:db8:2::16  dev eth2 weight 1

   - on a failure after the insertion of the first nexthop (which means
     the original route has been replaced in the FIB), a notification is
     sent with the successful nexthops and then the nexthops are deleted
     with one notification per hop. This is consistent with how it works
     today except the successful additions are coalesced into 1
     notification.

3. Route Delete
   - delete of entire multipath route using prefix/length only 1
     notification is generated:
    $ ip -6 ro del vrf red 2001:db8:200::/120

    $ ip mon route
    Deleted 2001:db8:200::/120 table red metric 1024
	    nexthop via 2001:db8:1::16  dev eth1 weight 1
	    nexthop via 2001:db8:2::16  dev eth2 weight 1

   - if a delete request contains nexthops one notification is
     generated per nexthop deleted. This is unavoidable since IPv6
     alllows a single nexthop to be deleted within a multipath route

4. Route Appends
   - IPv6 allows nexthops to be appended to an existing route. In this
     case one notification is sent for the new route with the append
     flag set.

    $ ip -6 ro append vrf red 2001:db8:200::/120 nexthop via 2001:db8:2::20 nexthop via 2001:db8:1::20

    $ ip mon route
    Append 2001:db8:200::/120 table red metric 1024
	    nexthop via 2001:db8:1::2  dev eth1 weight 1
	    nexthop via 2001:db8:2::2  dev eth2 weight 1
	    nexthop via 2001:db8:2::20  dev eth2 weight 1
	    nexthop via 2001:db8:1::20  dev eth1 weight 1

  - on failure of an append, a notification is sent with the route
    containing all of the nexthops successfully added, and it is
    followed by delete notifications as the hops are removed
    returning the route to its prior state. This is consistent with
    how it works today except the successful additions are coalesced
    into 1 notification.

Addresses some of the inconsistencies also noted by Roopa at netdev0.1:
https://www.netdev01.org/docs/prabhu-linux_ipv4_ipv6_inconsistencies_talk_slides.pdf

v4
- changed series to do encoding in 1 patch and updating notificatons
  in separate patches to make it easier to review and understand

- 1 notification for delete when using prefix/length; 1 notification for
  append

- handle delete of a single nexthop without RTA_MULTIPATH in delete request

- upated commit messages and cover letter

v3
- removed the need for a user API to opt-in to change. Requiring an
  API just shifts the difference from same API with different
  behavior to different API to achieve equivalent behavior
- route notifications changed to use RTA_MULTIPATH for add and replace
- upated commit messages and cover letter

v2
- fixed locking in patch 1 as noted by DaveM
- changed user API for patch 2 to require an rtmsg with RTM_F_ALL_NEXTHOPS
  set in rtm_flags
- revamped explanation of patch 2 and cover letter
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

ip6_print_replace_route_err logs an error if a route replace fails with
IPv6 addresses in the full format. e.g,:

IPv6: IPV6: multipath route replace failed (check consistency of installed routes): 2001:0db8:0200:0000:0000:0000:0000:0000 nexthop 2001:0db8:0001:0000:0000:0000:0000:0016 ifi 0

Change the message to dump the addresses in the compressed format.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If an entire multipath route is deleted using prefix and len (without any
nexthops), send a single RTM_DELROUTE notification with the full route
using RTA_MULTIPATH. This is done by generating the skb before the route
delete when all of the sibling routes are still present but sending it
after the route has been removed from the FIB. The skip_notify flag
is used to tell the lower fib code not to send notifications for the
individual nexthop routes.

If a route is deleted using RTA_MULTIPATH for any nexthops or a single
nexthop entry is deleted, then the nexthops are deleted one at a time with
notifications sent as each hop is deleted. This is necessary given that
IPv6 allows individual hops within a route to be deleted.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change ip6_route_multipath_add to send one notifciation with the full
route encoded with RTA_MULTIPATH instead of a series of individual routes.
This is done by adding a skip_notify flag to the nl_info struct. The
flag is used to skip sending of the notification in the fib code that
actually inserts the route. Once the full route has been added, a
notification is generated with all nexthops.

ip6_route_multipath_add handles 3 use cases: new routes, route replace,
and route append. The multipath notification generated needs to be
consistent with the order of the nexthops and it should be consistent
with the order in a FIB dump which means the route with the first nexthop
needs to be used as the route reference. For the first 2 cases (new and
replace), a reference to the route used to send the notification is
obtained by saving the first route added. For the append case, the last
route added is used to loop back to its first sibling route which is
the first nexthop in the multipath route.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

IPv6 returns multipath routes as a series of individual routes making
their display and handling by userspace different and more complicated
than IPv4, putting the burden on the user to see that a route is part of
a multipath route and internally creating a multipath route if desired
(e.g., libnl does this as of commit 29b71371e764). This patch addresses
this difference, allowing multipath routes to be returned using the
RTA_MULTIPATH attribute.

The end result is that IPv6 multipath routes can be treated and displayed
in a format similar to IPv4:

    $ ip -6 ro ls vrf red
    2001:db8:1::/120 dev eth1 proto kernel metric 256  pref medium
    2001:db8:2::/120 dev eth2 proto kernel metric 256  pref medium
    2001:db8:200::/120 metric 1024
	    nexthop via 2001:db8:1::2  dev eth1 weight 1
	    nexthop via 2001:db8:2::2  dev eth2 weight 1
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

IPv4 allows multipath routes to be deleted using just the prefix and
length. For example:
    $ ip ro ls vrf red
    unreachable default metric 8192
    1.1.1.0/24
        nexthop via 10.100.1.254  dev eth1 weight 1
        nexthop via 10.11.200.2  dev eth11.200 weight 1
    10.11.200.0/24 dev eth11.200 proto kernel scope link src 10.11.200.3
    10.100.1.0/24 dev eth1 proto kernel scope link src 10.100.1.3

    $ ip ro del 1.1.1.0/24 vrf red

    $ ip ro ls vrf red
    unreachable default metric 8192
    10.11.200.0/24 dev eth11.200 proto kernel scope link src 10.11.200.3
    10.100.1.0/24 dev eth1 proto kernel scope link src 10.100.1.3

The same notation does not work with IPv6 because of how multipath routes
are implemented for IPv6. For IPv6 only the first nexthop of a multipath
route is deleted if the request contains only a prefix and length. This
leads to unnecessary complexity in userspace dealing with IPv6 multipath
routes.

This patch allows all nexthops to be deleted without specifying each one
in the delete request. Internally, this is done by walking the sibling
list of the route matching the specifications given (prefix, length,
metric, protocol, etc).

    $  ip -6 ro ls vrf red
    2001:db8:1::/120 dev eth1 proto kernel metric 256  pref medium
    2001:db8:2::/120 dev eth2 proto kernel metric 256  pref medium
    2001:db8:200::/120 via 2001:db8:1::2 dev eth1 metric 1024  pref medium
    2001:db8:200::/120 via 2001:db8:2::2 dev eth2 metric 1024  pref medium
    ...

    $ ip -6 ro del vrf red 2001:db8:200::/120

    $ ip -6 ro ls vrf red
    2001:db8:1::/120 dev eth1 proto kernel metric 256  pref medium
    2001:db8:2::/120 dev eth2 proto kernel metric 256  pref medium
    ...

Because IPv6 allows individual nexthops to be deleted without deleting
the entire route, the ip6_route_multipath_del and non-multipath code
path (ip6_route_del) have to be discriminated so that all nexthops are
only deleted for the latter case. This is done by making the existing
fc_type in fib6_config a u16 and then adding a new u16 field with
fc_delete_all_nh as the first bit.
Suggested-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since commit 364b6055 ("net: busy-poll: return busypolling status to
drivers"), napi_complete_done() returns a boolean that can be used
by drivers to conditionally rearm interrupts.

This patch changes virtio_net to use this boolean to avoid a bit of
overhead for busy-poll users.

Jason reports about 1.1% improvement for 1 byte TCP_RR (burst 100).
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
40GbE Intel Wired LAN Driver Updates 2017-02-03

This series contains updates to i40e/i40evf only.

Jake fixes up the driver to not call i40e_vsi_kill_vlan() or
i40e_vsi_add_vlan() when the PVID is set or when the VID is less than 1.
Cleaned up a check which really is not needed since there is no real
reason why we cannot just call i40e_del_mac_all_vlan() directly.  Renamed
functions to better reflect their actual purpose and how they function
in a more clear manner.

Bimmy cleans up unused/deprecated macros.

Mitch cleans up unused device ids which were intended for use when
running Linux VF drivers under Hyper-V, but found to be not needed.
Then cleaned up a function that is no longer needed since the client
open and close functions were refactored.  Adds a sleep without timeout
until the reply from the PF driver has been received since the iWARP
client cannot continue until the operation has been completed.

Tushar Dave fixes an issue seen on SPARC where the use of the 'packed'
directive was causing kernel unaligned errors.

Alex does a refactor to pull some data off of the stack and store it
in the transmit buffer info section of the transmit ring.

Alan fixes a bug which was caused by passing a bad register value to the
firmware, by refactoring the macro INTRL_USEC_TO_REG into a static
inline function.  Also added feedback to the user as to the actual
interrupt rate limit being used when it differs from the requested limit.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

My recent change missed fact that UFO would perform a complete
UDP checksum before segmenting in frags.

In this case skb->ip_summed is set to CHECKSUM_NONE.

We need to add this valid case to skb_needs_check()

Fixes: b2504a5d ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We added generic support for busy polling in NAPI layer in linux-4.5

No network driver uses ndo_busy_poll() anymore, we can get rid
of the pointer in struct net_device_ops, and its use in sk_busy_loop()

Saves NETIF_F_BUSY_POLL features bit.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We do polling generically these days.
Signed-off-by: David S. Miller <davem@davemloft.net>

In linux-4.5, busy polling was implemented in core
NAPI stack, meaning that all custom implementation can
be removed from drivers.

Not only we remove lot's of code, we also remove one lock
operation in fast path, and allow GRO to do its job.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In linux-4.5, busy polling was implemented in core
NAPI stack, meaning that all custom implementation can
be removed from drivers.

Not only we remove lot's of code, we also remove one lock
operation in fast path, and allow GRO to do its job.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for your net-next
tree, they are:

1) Stash ctinfo 3-bit field into pointer to nf_conntrack object from
   sk_buff so we only access one single cacheline in the conntrack
   hotpath. Patchset from Florian Westphal.

2) Don't leak pointer to internal structures when exporting x_tables
   ruleset back to userspace, from Willem DeBruijn. This includes new
   helper functions to copy data to userspace such as xt_data_to_user()
   as well as conversions of our ip_tables, ip6_tables and arp_tables
   clients to use it. Not surprinsingly, ebtables requires an ad-hoc
   update. There is also a new field in x_tables extensions to indicate
   the amount of bytes that we copy to userspace.

3) Add nf_log_all_netns sysctl: This new knob allows you to enable
   logging via nf_log infrastructure for all existing netnamespaces.
   Given the effort to provide pernet syslog has been discontinued,
   let's provide a way to restore logging using netfilter kernel logging
   facilities in trusted environments. Patch from Michal Kubecek.

4) Validate SCTP checksum from conntrack helper, from Davide Caratti.

5) Merge UDPlite conntrack and NAT helpers into UDP, this was mostly
   a copy&paste from the original helper, from Florian Westphal.

6) Reset netfilter state when duplicating packets, also from Florian.

7) Remove unnecessary check for broadcast in IPv6 in pkttype match and
   nft_meta, from Liping Zhang.

8) Add missing code to deal with loopback packets from nft_meta when
   used by the netdev family, also from Liping.

9) Several cleanups on nf_tables, one to remove unnecessary check from
   the netlink control plane path to add table, set and stateful objects
   and code consolidation when unregister chain hooks, from Gao Feng.

10) Fix harmless reference counter underflow in IPVS that, however,
    results in problems with the introduction of the new refcount_t
    type, from David Windsor.

11) Enable LIBCRC32C from nf_ct_sctp instead of nf_nat_sctp,
    from Davide Caratti.

12) Missing documentation on nf_tables uapi header, from Liping Zhang.

13) Use rb_entry() helper in xt_connlimit, from Geliang Tang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Jiri Pirko says:

====================
mlxsw: Introduce TC Flower offload using TCAM

This patchset introduces support for offloading TC cls_flower and actions
to Spectrum TCAM-base policy engine.

The patchset contains patches to allow work with flexible keys and actions
which are used in Spectrum TCAM.

It also contains in-driver infrastructure for offloading TC rules to TCAM HW.
The TCAM management code is simple and limited for now. It is going to be
extended as a follow-up work.

The last patch uses the previously introduced infra to allow to implement
cls_flower offloading. Initially, only limited set of match-keys and only
a drop and forward actions are supported.

As a dependency, this patchset introduces parman - priority array
area manager - as a library.

v1->v2:
- patch11:
  - use __set_bit and __test_and_clear_bit as suggested by DaveM
- patch16:
  - Added documentation to the API functions as suggested by Tom Herbert
- patch17:
  - use __set_bit and __clear_bit as suggested by DaveM
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Extend the existing setup_tc ndo call and allow to offload cls_flower
rules. Only limited set of dissector keys and actions are supported now.
Use previously introduced ACL infrastructure to offload cls_flower rules
to be processed in the HW.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver that offloads flower rules needs to know with which priority
user inserted the rules. So add this information into offload struct.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add ACL core infrastructure for Spectrum ASIC. This infra provides an
abstraction layer over specific HW implementations. There are two basic
objects used. One is "rule" and the second is "ruleset" which serves as a
container of multiple rules. In general, within one ruleset the rules are
allowed to have multiple priorities and masks. Each ruleset is bound to
either ingress or egress a of port netdevice.

The initial TCAM implementation is very simple and limited. It utilizes
parman lsort manager to take care of TCAM region layout.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This introduces a infrastructure for management of linear priority
areas. Priority order in an array matters, however order of items inside
a priority group does not matter.

As an initial implementation, L-sort algorithm is used. It is quite
trivial. More advanced algorithm called P-sort will be introduced as a
follow-up. The infrastructure is prepared for other algos.

Alongside this, a testing module is introduced as well.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Similar to list_for_each_entry_continue and its reverse variant
list_for_each_entry_continue_reverse, introduce reverse helper for
list_for_each_entry_from.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>