mlx5 devices were observed generating MLX5_PORT_CHANGE_SUBTYPE_ACTIVE
events without an intervening MLX5_PORT_CHANGE_SUBTYPE_DOWN. This
breaks link flap detection based on Linux carrier state transition
count as netif_carrier_on() does nothing if carrier is already on.
Make sure we count such events.

netif_carrier_event() increments the counters and fires the linkwatch
events. The latter is not necessary for the use case but seems like
the right thing to do.
Signed-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSaeed Mahameed <saeedm@nvidia.com>

Dmytro Linkin says:

====================
devlink: rate objects API

Resending without RFC.

Currently kernel provides a way to change tx rate of single VF in
switchdev mode via tc-police action. When lots of VFs are configured
management of theirs rates becomes non-trivial task and some grouping
mechanism is required. Implementing such grouping in tc-police will bring
flow related limitations and unwanted complications, like:
- tc-police is a policer and there is a user request for a traffic
  shaper, so shared tc-police action is not suitable;
- flows requires net device to be placed on, means "groups" wouldn't
  have net device instance itself. Taking into the account previous
  point was reviewed a sollution, when representor have a policer and
  the driver use a shaper if qdisc contains group of VFs - such approach
  ugly, compilated and misleading;
- TC is ingress only, while configuring "other" side of the wire looks
  more like a "real" picture where shaping is outside of the steering
  world, similar to "ip link" command;

According to that devlink is the most appropriate place.

This series introduces devlink API for managing tx rate of single devlink
port or of a group by invoking callbacks (see below) of corresponding
driver. Also devlink port or a group can be added to the parent group,
where driver responsible to handle rates of a group elements. To achieve
all of that new rate object is added. It can be one of the two types:
- leaf - represents a single devlink port; created/destroyed by the
  driver and bound to the devlink port. As example, some driver may
  create leaf rate object for every devlink port associated with VF.
  Since leaf have 1to1 mapping to it's devlink port, in user space it is
  referred as pci/<bus_addr>/<port_index>;
- node - represents a group of rate objects; created/deleted by request
  from the userspace; initially empty (no rate objects added). In
  userspace it is referred as pci/<bus_addr>/<node_name>, where node name
  can be any, except decimal number, to avoid collisions with leafs.

devlink_ops extended with following callbacks:
- rate_{leaf|node}_tx_{share|max}_set
- rate_node_{new|del}
- rate_{leaf|node}_parent_set

KAPI provides:
- creation/destruction of the leaf rate object associated with devlink
  port
- destruction of rate nodes to allow a vendor driver to free allocated
  resources on driver removal or due to the other reasons when nodes
  destruction required

UAPI provides:
- dumping all or single rate objects
- setting tx_{share|max} of rate object of any type
- creating/deleting node rate object
- setting/unsetting parent of any rate object

Added devlink rate object support for netdevsim driver

Issues/open questions:
- Does user need DEVLINK_CMD_RATE_DEL_ALL_CHILD command to clean all
  children of particular parent node? For example:
  $ devlink port function rate flush netdevsim/netdevsim10/group
- priv pointer passed to the callbacks is a source of bugs; in leaf case
  driver can embed rate object into internal structure and use
  container_of() on it; in node case it cannot be done since nodes are
  created from userspace

v1->v2:
- fixed kernel-doc for devlink_rate_leaf_{create|destroy}()
- s/func/function/ for all devlink port command occurences

v2->v3:
- devlink:
  - added devlink_rate_nodes_destroy() function
- netdevsim:
  - added call of devlink_rate_nodes_destroy() function
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add devlink rate objects section at devlink port documentation.
Add devlink rate support info at netdevsim devlink documentation.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Test verifies that netdevsim correctly implements devlink ops callbacks
that set node as a parent of devlink leaf or node rate object.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement new devlink ops that allow setting rate node as a parent for
devlink port (leaf) or another devlink node through devlink API.
Expose parent names to netdevsim debugfs in read only mode.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refactor DEVLINK_CMD_RATE_{GET|SET} command handlers to support setting
a node as a parent for another rate object (leaf or node) by means of
new attribute DEVLINK_ATTR_RATE_PARENT_NODE_NAME. Extend devlink ops
with new callbacks rate_{leaf|node}_parent_set() to set node as a parent
for rate object to allow supporting drivers to implement rate grouping
through devlink. Driver implementations are allowed to support leafs
or node children only. Invoking callback with NULL as parent should be
threated by the driver as unset parent action.
Extend rate object struct with reference counter to disallow deleting a
node with any child pointing to it. User should unset parent for the
child explicitly.

Example:

$ devlink port function rate add netdevsim/netdevsim10/group1

$ devlink port function rate add netdevsim/netdevsim10/group2

$ devlink port function rate set netdevsim/netdevsim10/group1 parent group2

$ devlink port function rate show netdevsim/netdevsim10/group1
netdevsim/netdevsim10/group1: type node parent group2

$ devlink port function rate set netdevsim/netdevsim10/group1 noparent
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Test verifies that it is possible to create, delete and set min/max tx
rate of devlink rate node on netdevsim VF.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement new devlink ops that allow creation, deletion and setting of
shared/max tx rate of devlink rate nodes through devlink API.
Expose rate node and it's tx rates to netdevsim debugfs.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement support for DEVLINK_CMD_RATE_{NEW|DEL} commands that are used
to create and delete devlink rate nodes. Add new attribute
DEVLINK_ATTR_RATE_NODE_NAME that specify node name string. The node name
is an alphanumeric identifier. No valid node name can be a devlink port
index, eg. decimal number. Extend devlink ops with new callbacks
rate_node_{new|del}() and rate_node_tx_{share|max}_set() to allow
supporting drivers to implement ports rate grouping and setting tx rate
of rate nodes through devlink.
Expose devlink_rate_nodes_destroy() function to allow vendor driver do
proper cleanup of internally allocated resources for the nodes if the
driver goes down or due to any other reasons which requires nodes to be
destroyed.
Disallow moving device from switchdev to legacy mode if any node exists
on that device. User must explicitly delete nodes before switching mode.

Example:

$ devlink port function rate add netdevsim/netdevsim10/group1

$ devlink port function rate set netdevsim/netdevsim10/group1 \
        tx_share 10mbit tx_max 100mbit

Add + set command can be combined:

$ devlink port function rate add netdevsim/netdevsim10/group1 \
        tx_share 10mbit tx_max 100mbit

$ devlink port function rate show netdevsim/netdevsim10/group1
netdevsim/netdevsim10/group1: type node tx_share 10mbit tx_max 100mbit

$ devlink port function rate del netdevsim/netdevsim10/group1
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Test verifies that netdevsim VFs can set and retrieve shared/max tx
rate through new devlink API.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement new devlink ops that allow shared and max tx rate control for
devlink port rate objects (leafs) through devlink API.

Expose rate values of VF ports to netdevsim debugfs.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement support for DEVLINK_CMD_RATE_SET command with new attributes
DEVLINK_ATTR_RATE_TX_{SHARE|MAX} that are used to set devlink rate
shared/max tx rate values. Extend devlink ops with new callbacks
rate_leaf_tx_{share|max}_set() to allow supporting drivers to implement
rate control through devlink.

New attributes are optional. Driver implementations are allowed to
support either or both of them.

Shared rate example:

$ devlink port function rate set netdevsim/netdevsim10/0 tx_share 10mbit

$ devlink port function rate show netdevsim/netdevsim10/0
netdevsim/netdevsim10/0: type leaf tx_share 10mbit

Max rate example:

$ devlink port function rate set netdevsim/netdevsim10/0 tx_max 100mbit

$ devlink port function rate show netdevsim/netdevsim10/0
netdevsim/netdevsim10/0: type leaf tx_max 100mbit
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Test verifies that all netdevsim VF ports have rate leaf object created
by default.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Register devlink rate leaf objects per VF.
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow registering rate object for devlink ports with dedicated
devlink_rate_leaf_{create|destroy}() API. Implement new netlink
DEVLINK_CMD_RATE_GET command that is used to retrieve rate object info.
Add new DEVLINK_CMD_RATE_{NEW|DEL} commands that are used for
notifications when creating/deleting leaf rate object.

Rate API is intended to be used for rate limiting of individual
devlink ports (leafs) and their aggregates (nodes).

Example:

$ devlink port show
pci/0000:03:00.0/0
pci/0000:03:00.0/1

$ devlink port function rate show
pci/0000:03:00.0/0: type leaf
pci/0000:03:00.0/1: type leaf
Co-developed-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NVlad Buslov <vladbu@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Implement callbacks to set/get eswitch mode value. Add helpers to check
current mode.

Instantiate VFs' net devices and devlink ports on switchdev enabling and
remove them on legacy enabling. Changing number of VFs while in
switchdev mode triggers VFs creation/deletion.

Also disable NDO API callback to set VF rate, since it's legacy API.
Switchdev API to set VF rate will be implemented in one of the next
patches.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow creation of netdevsim ports for VFs along with allocations of
corresponding net devices and devlink ports.
Add enums and helpers to distinguish PFs' ports from VFs' ports.

Ports creation/deletion debugfs API intended to be used with physical
ports only.
VFs instantiation will be done in one of the next patches.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define type of ports, which netdevsim driver currently operates with as
PF. Define new port type - VF, which will be implemented in following
patches. Add helper functions to distinguish them. Add helper function
to get VF index from port index.

Add port indexing logic where PFs' indexes starts from 0, VFs' - from
NSIM_DEV_VF_PORT_INDEX_BASE.
All ports uses same index pool, which means that PF port may be created
with index from VFs' indexes range.
Maximum number of VFs, which the driver can allocate, is limited by
UINT_MAX - BASE.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move VFs disabling from device release() to nsim_dev_reload_destroy() to
make VFs disabling and ports removal simultaneous.
This is a requirement for VFs ports implemented in next patches.
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently there is no limit to the number of VFs netdevsim can enable.
In a real systems this value exist and used by the driver.
Fore example, some features might need to consider this value when
allocating memory.

Expose max_vfs variable to debugfs as configurable resource. If are VFs
configured (num_vfs != 0) then changing of max_vfs not allowed.
Co-developed-by: NYuval Avnery <yuvalav@nvidia.com>
Signed-off-by: NYuval Avnery <yuvalav@nvidia.com>
Signed-off-by: NDmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: NJiri Pirko <jiri@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Simon Horman says:

====================
Introduce conntrack offloading to the nfp driver

Louis Peens says:

This is the first in a series of patches to offload conntrack
to the nfp. The approach followed is to flatten out three
different flow rules into a single offloaded flow. The three
different flows are:

1) The rule sending the packet to conntrack (pre_ct)
2) The rule matching on +trk+est after a packet has been through
   conntrack. (post_ct)
3) The rule received via callback from the netfilter (nft)

In order to offload a flow we need a combination of all three flows, but
they could be added/deleted at different times and in different order.

To solve this we save potential offloadable CT flows in the driver,
and every time we receive a callback we check against these saved flows
for valid merges. Once we have a valid combination of all three flows
this will be offloaded to the NFP. This is demonstrated in the diagram
below.

	+-------------+                      +----------+
	| pre_ct flow +--------+             | nft flow |
	+-------------+        v             +------+---+
	                  +----------+              |
	                  | tc_merge +--------+     |
	                  +----------+        v     v
	+--------------+       ^           +-------------+
	| post_ct flow +-------+       +---+nft_tc merge |
	+--------------+               |   +-------------+
	                               |
	                               |
	                               |
	                               v
	                        Offload to nfp

This series is only up to the point of the pre_ct and post_ct
merges into the tc_merge. Follow up series will continue
to add the nft flows and merging of these flows with the result
of the pre_ct and post_ct merged flows.

Changes since v2:
- nfp: flower-ct: add zone table entry when handling pre/post_ct flows
    Fixed another docstring. Should finally have the patch check
    environment properly configured now to avoid more of these.
- nfp: flower-ct: add tc merge functionality
    Fixed warning found by "kernel test robot <lkp@intel.com>"
    Added code comment explaining chain_index comparison

Changes since v1:
- nfp: flower-ct: add ct zone table
    Fixed unused variable compile warning
    Fixed missing colon in struct description
====================
Acked-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add merging of pre/post_ct flow rules into the tc_merge table.
Pre_ct flows needs to be merge with post_ct flows and vice versa.

This needs to be done for all flows in the same zone table, as well
as with the wc_zone_table, which is for flows masking out ct_zone
info.

Cleanup is happening when all the tables are cleared up and prints
a warning traceback as this is not expected in the final version.
At this point we are not actually returning success for the offload,
so we do not get any delete requests for flows, so we can't delete
them that way yet. This means that cleanup happens in what would
usually be an exception path.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the table required to store the merge result of pre_ct and post_ct
flows. This is just the initial setup and teardown of the table,
the implementation will be in follow-up patches.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a hashtable which contains entries to map flow cookies to ct
flow entries. Currently the entries are added and not used, but
follow-up patches will use this for stats updates and flow deletes.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit starts adding the structures and lists that will
be used in follow up commits to enable offloading of conntrack.
Some stub functions are also introduced as placeholders by
this commit.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Start populating the pre/post_ct handler functions. Add a zone entry
to the zone table, based on the zone information from the flow. In
the case of a post_ct flow which has a wildcarded match on the zone
create a special entry.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add initial zone table to nfp_flower_priv. This table will be used
to store all the information required to offload conntrack.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add checks to see if a flow is a conntrack flow we can potentially
handle. Just stub out the handling the different conntrack flows.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is in preparation for conntrack offload support which makes
used of different chains. Add explicit checks for conntrack and
non-zero chains in the add_offload path.
Signed-off-by: NLouis Peens <louis.peens@corigine.com>
Signed-off-by: NYinjun Zhang <yinjun.zhang@corigine.com>
Signed-off-by: NSimon Horman <simon.horman@corigine.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix some spelling mistakes in comments:
thats  ==> that's
serivce  ==> service
varience  ==> variance
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

targetted  ==> targeted
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix some spelling mistakes in comments:
udpate  ==> update
retreive  ==> retrieve
accidentially  ==> accidentally
correspondig  ==> corresponding
adddress  ==> address
estabilish  ==> establish
commplete  ==> complete
Unkown  ==> Unknown
triggerd  ==> triggered
transtion  ==> transition
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

reseting  ==> resetting
alloced  ==> allocated
accomodate  ==> accommodate
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

atribute  ==> attribute
Signed-off-by: NZheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use meaningfull micro IPV4_MIN_MTU
Signed-off-by: Nzhang kai <zhangkaiheb@126.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This helps validating DTS files.

Introduced changes:
1. Swapped #address-cells and #size-cells values
2. Renamed node: s/enet-gphy/ethernet-phy@/
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter updates for net-next:

1) Support for SCTP chunks matching on nf_tables, from Phil Sutter.

2) Skip LDMXCSR, we don't need a valid MXCSR state. From Stefano Brivio.

3) CONFIG_RETPOLINE for nf_tables set lookups, from Florian Westphal.

4) A few Kconfig leading spaces removal, from Juerg Haefliger.

5) Remove spinlock from xt_limit, from Jason Baron.

6) Remove useless initialization in xt_CT, oneliner from Yang Li.

7) Tree-wide replacement of netlink_unicast() by nfnetlink_unicast().

8) Reduce footprint of several structures: xt_action_param,
   nft_pktinfo and nf_hook_state, from Florian.

10) Add nft_thoff() and nft_sk() helpers and use them, also from Florian.

11) Fix documentation in nf_tables pipapo avx2, from Florian Westphal.

12) Fix clang-12 fmt string warnings, also from Florian.
====================

Sharath Chandra Vurukala says:

====================
net: qualcomm: rmnet: Enable Mapv5

This series introduces the MAPv5 packet format.

   Patch 0 documents the MAPv4/v5.
   Patch 1 introduces the MAPv5 and the Inline checksum offload for RX/Ingress.
   Patch 2 introduces the MAPv5 and the Inline checksum offload for TX/Egress.

   A new checksum header format is used as part of MAPv5.For RX checksum offload,
   the checksum is verified by the HW and the validity is marked in the checksum
   header of MAPv5. For TX, the required metadata is filled up so hardware can
   compute the checksum.

   v1->v2:
   - Fixed the compilation errors, warnings reported by kernel test robot.
   - Checksum header definition is expanded to support big, little endian
           formats as mentioned by Jakub.

   v2->v3:
   - Fixed compilation errors reported by kernel bot for big endian flavor.

   v3->v4:
   - Made changes to use masks instead of C bit-fields as suggested by Jakub/Alex.

   v4->v5:
   - Corrected checkpatch errors and warnings reported by patchwork.

   v5->v6:
   - Corrected the bug identified by Alex and incorporated all his comments.

   v6->v7:
   - Removed duplicate inclusion of linux/bitfield.h in rmnet_map_data.c

   v7->v8:
   - Have addressed comments given by JAkub on v7 patches.
   - As suggested by Jakub, skb_cow_head() is used instead of expanding
     the head directly. This is now done in  rmnet_map_egress_handler().
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adding support for MAPv5 egress packets.

This involves adding the MAPv5 header and setting the csum_valid_required
in the checksum header to request HW compute the checksum.

Corresponding stats are incremented based on whether the checksum is
computed in software or HW.

New stat has been added which represents the count of packets whose
checksum is calculated by the HW.
Signed-off-by: NSharath Chandra Vurukala <sharathv@codeaurora.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adding support for processing of MAPv5 downlink packets.
It involves parsing the Mapv5 packet and checking the csum header
to know whether the hardware has validated the checksum and is
valid or not.

Based on the checksum valid bit the corresponding stats are
incremented and skb->ip_summed is marked either CHECKSUM_UNNECESSARY
or left as CHEKSUM_NONE to let network stack revalidate the checksum
and update the respective snmp stats.

Current MAPV1 header has been modified, the reserved field in the
Mapv1 header is now used for next header indication.
Signed-off-by: NSharath Chandra Vurukala <sharathv@codeaurora.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>