Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before the device is opened, the carrier state should be off.  It
will not race with the link interrupt if we set it before calling
register_netdev().
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Don't set the default size to 128K if it is 5762.  Instead, rely on the
size we obtain from NVRAM location 0xf0.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This chip supports Energy Efficient Ethernet.  The existing code only
supports a smaller set of devices with 5718 PCI ID.  Expand support for
all devices with the same 5717 B0 chip ID.
Signed-off-by: Michael Chan <mchan@broadocm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The patch also adds a couple of fixes

 - For the 57766 and non Ax versions of 57765, bootcode needs to setup
   the PCIE Fast Training Sequence (FTS) value to prevent transmit hangs.
   Unfortunately, it does not have enough room in the selfboot case (i.e.
   devices with no NVRAM).  The driver needs to implement this.

 - For performance reasons, the 2k DMA engine mode on the 57766 should
   be enabled and dma size limited to 2k for standard sized packets.
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Even for non-pfmalloc SKBs, __netif_receive_skb() will do a
tsk_restore_flags() on current unconditionally.

Make __netif_receive_skb() a shim around the existing code, renamed to
__netif_receive_skb_core().  Let __netif_receive_skb() wrap the
__netif_receive_skb_core() call with the task flag modifications, if
necessary.
Signed-off-by: David S. Miller <davem@davemloft.net>

This fixes a less obvious error on one hand, and prevents futher
similar errors by disambiguating and optimizing RxFCB indication,
on the other hand.

The error consists in NETIF_F_HW_VLAN_TX flag being used as an
indication of Rx FCB insertion. This happened as soon gfar_uses_fcb(),
which despite its name indicates Rx FCB insertion, started
incorporating is_vlan_on().
is_vlan_on(), on the other hand, is also a misleading construct because
we need to differentiate b/w hw VLAN extraction/VLEX (marked by VLAN_RX
flag) and hw VLAN insertion/VLINS (VLAN_TX flag), which are different
mechanisms using different types of FCBs.

The hw spec for the RxFCB feature is as follows:
In the case of RxBD rings, FCBs (Frame Control Block) are inserted by
the eTSEC whenever RCTRL[PRSDEP] is set to a non-zero value. Only one
FCB is inserted per frame (in the buffer pointed to by the RxBD with
bit F set). TOE acceleration for receive is enabled for all rx frames
in this case.

This patch introduces priv->uses_rxfcb field to quickly signal RxFCB
insertion in accordance with the specification above.

The dependency on FSL_GIANFAR_DEV_HAS_TIMER was also eliminated as
another source of confusion. The actual dependency is to priv->hwts_rx_en.
Upon changing priv->hwts_rx_en via IOCTL, the gfar device is being
restarted and on init_mac() the priv->hwts_rx_en flag determines RxFCB
insertion, and rctrl is programmed accordingly. The patch takes care
of this case too.

Though maybe not as self documenting as the inlining version uses_fcb(),
priv->uses_rxfcb has the main purpose to quickly signal, on the hot path,
that the incoming frame has a *Rx* FCB block inserted which needs to be
pulled out before passing the skb to the stack. This is a performance
critical operation, it needs to happen fast, that's why uses_rxfcb is
placed in the first cacheline of gfar_private.
This is also why a cached rctrl cannot be used instead: 1) because
we don't have 32 bits available in the first cacheline of gfar_priv
(but only 16); 2) bit operations are expensive on the hot path.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The controller's ref manual states clearly that when the hw Rx vlan
offload feature is enabled, meaning that the VLEX bit from RCTRL is
correctly enabled, then the hw performs automatic VLAN tag extraction
and deletion from the ethernet frames. So there's no point in trying to
increase the rx buff size when rxvlan is on, as the frame is actually
smaller.
And the Tx vlan hw accel feature (VLINS) has nothing to do with rx buff
size computation.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

No return code is expected from gfar_process_frame(), hence
change it to return void.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The change is significant since it affects the rx hot path.
Paul observed and documented the effects at asm level, see
below:

"It turns out that it does make a difference, since gfar_process_frame
gets inlined, and so the increment code gets moved out of line (I have
marked the if statment with * and the increment code within "-----"):

  ------------------------- as is currently ------------------
     4d14:       80 61 00 18     lwz     r3,24(r1)
     4d18:       7f c4 f3 78     mr      r4,r30
     4d1c:       48 00 00 01     bl      4d1c <gfar_clean_rx_ring+0x10c>
  *  4d20:       2f 83 00 04     cmpwi   cr7,r3,4
     4d24:       40 9e 00 1c     bne-    cr7,4d40
<gfar_clean_rx_ring+0x130>
        ----------------------------
     4d28:       81 3c 01 f8     lwz     r9,504(r28)
     4d2c:       81 5c 01 fc     lwz     r10,508(r28)
     4d30:       31 4a 00 01     addic   r10,r10,1
     4d34:       7d 29 01 94     addze   r9,r9
     4d38:       91 3c 01 f8     stw     r9,504(r28)
     4d3c:       91 5c 01 fc     stw     r10,508(r28)
        ----------------------------
     4d40:       a0 1f 00 24     lhz     r0,36(r31)
     4d44:       81 3f 00 00     lwz     r9,0(r31)
     4d48:       7f a4 eb 78     mr      r4,r29
     4d4c:       7f e3 fb 78     mr      r3,r31

  -------------------------- unlikely ------------------------
     4d14:       80 61 00 18     lwz     r3,24(r1)
     4d18:       7f c4 f3 78     mr      r4,r30
     4d1c:       48 00 00 01     bl      4d1c <gfar_clean_rx_ring+0x10c>
  *  4d20:       2f 83 00 04     cmpwi   cr7,r3,4
     4d24:       41 9e 03 94     beq-    cr7,50b8
<gfar_clean_rx_ring+0x4a8>
     4d28:       a0 1f 00 24     lhz     r0,36(r31)
     4d2c:       81 3f 00 00     lwz     r9,0(r31)
     4d30:       7f a4 eb 78     mr      r4,r29
     4d34:       7f e3 fb 78     mr      r3,r31
[...]
     50b8:       81 3c 01 f8     lwz     r9,504(r28)
     50bc:       81 5c 01 fc     lwz     r10,508(r28)
     50c0:       31 4a 00 01     addic   r10,r10,1
     50c4:       7d 29 01 94     addze   r9,r9
     50c8:       91 3c 01 f8     stw     r9,504(r28)
     50cc:       91 5c 01 fc     stw     r10,508(r28)
     50d0:       4b ff fc 58     b       4d28 <gfar_clean_rx_ring+0x118>

So, the increment does actually get moved ~1k away."

Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Group run-time critical fields within the 1st cacheline (32B)
followed by the tx|rx_queue reference arrays and the interrupt
group instances (gfargrp), all cacheline aligned.

This has several benefits. Firstly comes the performance benefit
by having the members required by the driver's hot path re-grouped
in the structure's first cache lines, whereas the unimportant
members were pushed towards the end of the struct.
Another benefit comes from eliminating a 24 byte memory hole that
was rendering gfar_priv's 2nd cacheline useless. The default gcc
layout of gfar_private leaves an implicit 24 byte hole after the
errata (enum) member. This patch fixes it.

The uchar bitfields were pushed towards the end of the struct
as these are not run-time performance critical (used for init
time operations). Because there is no other 2 byte member
around to couple the uchar bitfields memeber with, we will
have an addititnal 2 byte hole after the bitfields. This is
unsignificant however, and it doesn't influence gfar_priv's
size, because the whole structure is padded to be a 32B multiple.
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use device pointer (dev) to simplify the code and to
avoid double indirections, especially on the hot path.

Basically, instead of accessing priv to get the ofdev
reference and then accessing the ofdev structure to
dereference the needed dev pointer, we will get the
dev pointer directly from priv.

The dev pointer is required on the hot path, see gfar_new_rxbdp
or gfar_clean_rx_ring (or xmit), and this patch makes
it available directly from priv's 1st cacheline.

This change is reflected at asm level too, taking (the hot)
gfar_new_rxbdp():
initial version -
    18c0:	7c 7e 1b 78 	mr      r30,r3

    18d0:	81 69 04 3c 	lwz     r11,1084(r9)

    18d8:	34 6b 00 10 	addic.  r3,r11,16
    18dc:	41 82 00 08 	beq-    18e4

patched version -
    18d0:	80 69 04 38 	lwz     r3,1080(r9)

    18d8:	2f 83 00 00 	cmpwi   cr7,r3,0
    18dc:	41 9e 00 08 	beq-    cr7,18e4
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove unused device node pointer.
Remove duplicated SET_NETDEV_DEV().
Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Steffen Klassert says:

====================
1) Remove a duplicated call to skb_orphan() in pf_key, from Cong Wang.

2) Prepare xfrm and pf_key for algorithms without pf_key support,
   from Jussi Kivilinna.

3) Fix an unbalanced lock in xfrm_output_one(), from Li RongQing.

4) Add an IPsec state resolution packet queue to handle
   packets that are send before the states are resolved.

5) xfrm4_policy_fini() is unused since 2.6.11, time to remove it.
   From Michal Kubecek.

6) The xfrm gc threshold was configurable just in the initial
   namespace, make it configurable in all namespaces. From
   Michal Kubecek.

7) We currently can not insert policies with mark and mask
   such that some flows would be matched from both policies.
   Allow this if the priorities of these policies are different,
   the one with the higher priority is used in this case.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

They are only used within this file.

Cc: Vlad Yasevich <vyasevic@redhat.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The specs prescribe an immediate read of the interrupt mask after
disabling interrupts.  This patch updates the driver to match the
specs.
Signed-off-by: Nathan Hintz <nlhintz@hotmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We should use "__u16" instead of "u16" in the user-space visable
header.

Cc: Vlad Yasevich <vyasevic@redhat.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vlad Yasevich says:

====================
VLAN filtering/VLAN aware bridge

Changes since v10
* Updated implemenation of ndo_fdb_del in emulex and qlogic drivers.

Changes since v9:
* series re-ordering so make functionality more distinct.  Basic vlan
  filtering is patches 1-4.  Support for PVID/untagged vlans is patches
  5 and 6.  VLAN support for FDB/MDB is patches 7-11.  Patch 12 is
  still additional egress policy.
* Slight simplification to code that extracts the VID from skb.  Since we
  now depend on the vlan module, at the time of input skb_tci is guaranteed
  to be set if the packet had 8021q header.  We can simply refere to it.
* Changed the opaque 'parent' pointer from prior patches to a union so we
  can be much more explicit in our assignments.
* Lots of additional testing with STP turned on.  No issues were observed.

Changes since v8:
* Unified vlans_to_* calls into a single interface
* Fixed the rest of the issues report by Michal Miroslaw
* Fixed a bug where fdb entries were not created for all added vlans.

Changes since v7:
* Rebases on the latest net-next and removed the vlan wrapper patch from
the series.
* Fixed a crash in br_fdb_add/br_fdb_delete.

Changes since v6:
* VLANs are now stored in a VLAN bitmap per port.  This allows for O(1)
lookup at ingress and egress.  We simply check to see if the bit associated
with the vlan id is set in the map.  The drawback to this approach is that
it wastes some space when there is only a small number of VLANs.
* In addition to the build time configuration option, VLAN filtering also has
a configuration paramter in sysfs.  By default the filtering is turned off
and all traffic is permitted.  When the filtring is turned on, we do strict
matching to the filter configured.  Thus, if there is no configuration, all
packets are rejected.  This was done to make the behavior more streight
forward.  Without this (and if egress policy patch is rejected), the
decision for how to forward untagged traffic that was not filtered at ingress
is almost impossible to make.  It would not be right to deliver to every
port that has PVID set as, each port may have a different PVID.
* Separate egress policy bitmap patch has been isolated and is provided last
in the series.  This has been a more contentious piece of functionality and I
wanted to isolate it so that it could easily be dropped and not block the whole
series.

Changes since v5:
 - Pulled VLAN filtering into its own file and made it a configuration options.
 - Made new vlan filtering option dependent on VLAN_8021Q.
 - Got rid of HW filter inlines and moved then vlan_core.c.
   (All of the above suggested by Stephen Hemminger)

Changes since v4:
 - Pull per-port vlan data into its own structures and give it to the bridge
   device thus making bridge device behave like a regular port for vlan
   configuration.
 - Add a per-vlan 'untagged' bitmap that determins egress policy.  If a port
   is part of this bitmap, traffic egresses untagged.
 - PVID is now used for ingress policy only.  Incomming frames without VLAN tag
   are assigned to the PVID vlan.  Egress is determined via bitmap memberships.
 - Allow for incremental config of a vlan.  Now, PVID and untagged memberships
   may be set on existing vlans.  They however can NOT be cleared separately.
 - VLAN deletion is now done via RTM_DELLINK command for PF_BRIDGE family.
   This cleans up the netlink interface.

Changes since v3:
 - Re-integrated compiler problems that got left out last time.  Appologies.
 - checkpatches.pl errors fixed

Changes since v2:
 - Added inline functiosn to manimulate vlan hw filters and re-use in 8021q
   and bridge code.
 - Use rtnl_dereference (Michael Tsirkin)
 - Remove synchronize_net() call (Eric Dumazet)
 - Fix NULL ptr deref bug I introduced in br_ifinfo_notify.

Changes since v1:
 - Fixed some forwarding bugs.
 - Add vlan to local fdb entries.  New local entries are created per vlan
   to facilite correct forwarding to bridge interface.
 - Allow configuration of vlans directly on the bridge master device
   in addition to ports.

Changes since rfc v2:
 - Per-port vlan bitmap is gone and is replaced with a vlan list.
 - Added bridge vlan list, which is referenced by each port.  Entries in
   the birdge vlan list have port bitmap that shows which port are parts
   of which vlan.
 - Netlink API changes.
 - Dropped sysfs support for now.  If people think this is really usefull,
   can add it back.
 - Support for native/untagged vlans.

Changes since rfc v1:
 - Comments addressed regarding formatting and RCU usage
 - iocts have been removed and changed over the netlink interface.
 - Added support of user added ndb entries.
 - changed sysfs interface to export a bitmap.  Also added a write interface.
   I am not sure how much I like it, but it made my testing easier/faster.  I
   might change the write interface to take text instead of binary.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add an ability to configure a separate "untagged" egress
policy to the VLAN information of the bridge.  This superseeds PVID
policy and makes PVID ingress-only.  The policy is configured with a
new flag and is represented as a port bitmap per vlan.  Egress frames
with a VLAN id in "untagged" policy bitmap would egress
the port without VLAN header.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When VLAN is added to the port, a local fdb entry for that port
(the entry with the mac address of the port) is added for that
VLAN.  This way we can correctly determine if the traffic
is for the bridge itself.  If the address of the port changes,
we try to change all the local fdb entries we have for that port.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a user adds bridge neighbors, allow him to specify VLAN id.
If the VLAN id is not specified, the neighbor will be added
for VLANs currently in the ports filter list.  If no VLANs are
configured on the port, we use vlan 0 and only add 1 entry.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Acked-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add vlan_id to multicasts groups so that we know which vlan
each group belongs to and can correctly forward to appropriate vlan.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds vlan to unicast fdb entries that are created for
learned addresses (not the manually configured ones).  It adds
vlan id into the hash mix and uses vlan as an addditional parameter
for an entry match.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A user may designate a certain vlan as PVID.  This means that
any ingress frame that does not contain a vlan tag is assigned to
this vlan and any forwarding decisions are made with this vlan in mind.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

At ingress, any untagged traffic is assigned to the PVID.
Any tagged traffic is filtered according to membership bitmap.

At egress, if the vlan matches the PVID, the frame is sent
untagged.  Otherwise the frame is sent tagged.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using the RTM_GETLINK dump the vlan filter list of a given
bridge port.  The information depends on setting the filter
flag similar to how nic VF info is dumped.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a netlink interface to add and remove vlan configuration on bridge port.
The interface uses the RTM_SETLINK message and encodes the vlan
configuration inside the IFLA_AF_SPEC.  It is possble to include multiple
vlans to either add or remove in a single message.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When bridge forwards a frame, make sure that a frame is allowed
to egress on that port.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a frame arrives on a port or transmitted by the bridge,
if we have VLANs configured, validate that a given VLAN is allowed
to enter the bridge.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adds an optional infrustructure component to bridge that would allow
native vlan filtering in the bridge.  Each bridge port (as well
as the bridge device) now get a VLAN bitmap.  Each bit in the bitmap
is associated with a vlan id.  This way if the bit corresponding to
the vid is set in the bitmap that the packet with vid is allowed to
enter and exit the port.

Write access the bitmap is protected by RTNL and read access
protected by RCU.

Vlan functionality is disabled by default.
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In order to avoid any future surprises of kernel panics due to jprobes
function mismatches (as e.g. fixed in 4cb9d6ea: sctp: jsctp_sf_eat_sack:
fix jprobes function signature mismatch), we should check both function
types during build and scream loudly if they do not match. __same_type
resolves to __builtin_types_compatible_p, which is 1 in case both types
are the same and 0 otherwise, qualifiers are ignored. Tested by myself.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function jsctp_sf_eat_sack can be made static, no need to extend
its visibility.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some callers may want to know if PHY write succeed. Also make PHY
functions static, they are not exported anywhere.
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The current code expects that the last word (with valid bit)
of an MCC compl is DMAed in one shot. This may not be the case.
Remove this assertion.
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

cpdma_chan_destroy() on a NULL pointer is a no-op, so the NULL check in
cpdma_ctlr_destroy() can safely be removed.
Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Patch cef401de (net: fix possible wrong checksum
generation) fixed wrong checksum calculation but it broke TSO by
defining new GSO type but not a netdev feature for that type.
net_gso_ok() would not allow hardware checksum/segmentation
offload of such packets without the feature.

Following patch fixes TSO and wrong checksum. This patch uses
same logic that Eric Dumazet used. Patch introduces new flag
SKBTX_SHARED_FRAG if at least one frag can be modified by
the user. but SKBTX_SHARED_FRAG flag is kept in skb shared
info tx_flags rather than gso_type.

tx_flags is better compared to gso_type since we can have skb with
shared frag without gso packet. It does not link SHARED_FRAG to
GSO, So there is no need to define netdev feature for this.
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrey Vagin says:

====================
If a TCP socket will get live-migrated from one box to another the
timestamps (which are typically ON) will get screwed up -- the new
kernel will generate TS values that has nothing to do with what they
were on dump. The solution is to yet again fix the kernel and put a
"timestamp offset" on a socket.

A socket offset is added in places where externally visible tcp
timestamp option is parsed/initialized.

Connections in the SYN_RECV state are not supported, global
tcp_time_stamp is used for them, because repair mode doesn't support
this state. In a future it can be implemented by the similar way as for
TIME_WAIT sockets.

For time-wait sockets offset is inhereted by a proper tcp_sock.

A per-socket offset can be set only for sockets in repair mode.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

A socket timestamp is a sum of the global tcp_time_stamp and
a per-socket offset.

A socket offset is added in places where externally visible
tcp timestamp option is parsed/initialized.

Connections in the SYN_RECV state are not supported, global
tcp_time_stamp is used for them, because repair mode doesn't support
this state. In a future it can be implemented by the similar way
as for TIME_WAIT sockets.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

A timestamp can be set, only if a socket is in the repair mode.

This patch adds a new socket option TCP_TIMESTAMP, which allows to
get and set current tcp times stamp.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This functionality is used for restoring tcp sockets. A tcp timestamp
depends on how long a system has been running, so it's differ for each
host. The solution is to set a per-socket offset.

A per-socket offset for a TIME_WAIT socket is inherited from a proper
tcp socket.

tcp_request_sock doesn't have a timestamp offset, because the repair
mode for them are not implemented.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>