This patch allows reliable identification of netdevice interfaces connected
to openvswitch bridges. In particular, user space queries the netdev
interfaces belonging to the ports for statistics, up/down state, etc.
Datapath dump needs to provide enough information for the user space to be
able to do that.

Currently, only interface names are returned. This is not sufficient, as
openvswitch allows its ports to be in different name spaces and the
interface name is valid only in its name space. What is needed and generally
used in other netlink APIs, is the pair ifindex+netnsid.

The solution is addition of the ifindex+netnsid pair (or only ifindex if in
the same name space) to vport get/dump operation.

On request side, ideally the ifindex+netnsid pair could be used to
get/set/del the corresponding vport. This is not implemented by this patch
and can be added later if needed.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It will be used by openvswitch.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

IN6_ADDR_HSIZE is private to addrconf.c, move it here to avoid
confusion.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

pktgen accidentally used IN6_ADDR_HSIZE, instead of using the size of an
IPv6 address.

Since IN6_ADDR_HSIZE recently was increased from 16 to 256, this old
bug is hitting us.

Fixes: 3f27fb23 ("ipv6: addrconf: add per netns perturbation in inet6_addr_hash()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently n->flags is being operated on by a logical && operator rather
than a bitwise & operator. This looks incorrect as these should be bit
flag operations. Fix this.

Detected by CoverityScan, CID#1460398 ("Logical vs. bitwise operator")

Fixes: 245dc512 ("net: sched: cls_u32: call block callbacks for offload")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Average RTT is 32-bit thus full 64-bit division is redundant.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some time ago Eric Dumazet suggested a "hack the IFF_XMIT_DST_RELEASE
flag on the vlan netdev". But the last comment was "does not support
properly bonding/team.(If the real_dev->privflags IFF_XMIT_DST_RELEASE
bit changes, we want to update all the vlans at the same time )"

I've extended that patch to support changes of IFF_XMIT_DST_RELEASE in
bonding/team.
Both bonding and team call netdev_change_features() after recalculation
of features including priv_flags IFF_XMIT_DST_RELEASE bit. So the only
thing needed to support is to recheck this bit in
vlan_transfer_features().
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Vadim Fedorenko <vfedorenko@yandex-team.ru>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following sparse warnings:

drivers/net/phy/phylink.c:570:6: warning:
 symbol 'phylink_phy_change' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'wireless-drivers-next-for-davem-2017-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next

Kalle Valo says:

====================
wireless-drivers-next patches for 4.15

Mostly fixes this time, but also few new features.

Major changes:

wil6210

* remove ssid debugfs file

rsi

* add WOWLAN support for suspend, hibernate and shutdown states

ath10k

* add support for CCMP-256, GCMP and GCMP-256 ciphers on hardware
  where it's supported (QCA99x0 and QCA4019)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Files removed in 'net-next' had their license header updated
in 'net'.  We take the remove from 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>

Return success if the same dispatch function is being registered for
a given opcode and subcode, there by allow multiple switchdev enable
and disables.
Signed-off-by: Vijaya Mohan Guvva <vijaya.guvva@cavium.com>
Signed-off-by: Satanand Burla <satananda.burla@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jiri Pirko says:

====================
mlxsw: Handle changes in GRE configuration

Petr says:

Until now, when an IP tunnel was offloaded by the mlxsw driver, the
offload was pretty much static, and changes in Linux configuration were
not reflected in the hardware. That led to discrepancies between traffic
flows in slow path and fast path. The work-around used to be to remove
all routes that forward to the netdevice and re-add them. This is
clearly suboptimal, but actually, as of the decap-only patchset, it's
not even enough anymore, and one needs to go all the way and simply drop
the tunnel and recreate it correctly.

With this patchset, the NETDEV_CHANGE events that are generated for
changes of up'd tunnel netdevices are captured and interpreted to
correctly reconfigure the HW in accordance with changes requested at the
software layer. In addition, NETDEV_CHANGEUPPER, NETDEV_UP and
NETDEV_DOWN are now handled not only for tunnel devices themselves, but
also for their bound devices. Each change is then translated to one or
more of the following updates to the HW configuration:

- refresh of offload of local route that corresponds to tunnel's local
  address
- refresh of the loopback RIF
- refresh of offloads of routes that forward to the changed tunnel
- removal of tunnel offloads

These tools are used to implement the following configuration changes:

- addition of a new offloadable tunnel with local address that conflicts
  with that of an already-offloaded tunnel (the existing tunnel is
  onloaded, the new one isn't offloaded)
- changes to TTL, TOS that make tunnel unsuitable for offloading
- changes to ikey, okey, remote
- changes to local, which when they cause conflict with another
  tunnel, lead to onloading of both newly-conflicting tunnels
- migration of a bound device of an offloaded tunnel device to a
  different VRF
- changes to what device is bound to a tunnel device (i.e. like what
  "ip tunnel change name g dev another" does)
- changes to up / down state of a bound device. A down bound device
  doesn't forward encapsulated traffic anymore, but decap still works.

This patchset starts with a suite of patches that adapt the existing
code base step by step to facilitate introduction of the offloading
code. The five substantial patches at the end then implement the changes
mentioned above.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When the bound device of a tunnel device is down, encapsulated packets
are not egressed anymore, but tunnel decap still works. Extend
mlxsw_sp_nexthop_rif_update() to take IFF_UP into consideration when
deciding whether a given next hop should be offloaded.

Because the new logic was added to mlxsw_sp_nexthop_rif_update(), this
fixes the case where a newly-added tunnel has a down bound device, which
would previously be fully offloaded. Now the down state of the bound
device is noted and next hops forwarding to such tunnel are not
offloaded.

In addition to that, notice NETDEV_UP and NETDEV_DOWN of a bound device
to force refresh of tunnel encap route offloads.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a bound device of an IP-in-IP tunnel changes, such as through
'ip tunnel change name $name dev $dev', the loopback backing the tunnel
needs to be recreated.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Changes to L3 tunnel netdevices (through `ip tunnel change' as well as
`ip link set') lead to NETDEV_CHANGE being generated on the tunnel
device. Because what is relevant for the tunnel in question depends on
the tunnel type, handling of the event is dispatched to the IPIP module
through a newly-added interface mlxsw_sp_ipip_ops.ol_netdev_change().

IPIP tunnels now remember the last set of tunnel parameters in struct
mlxsw_sp_ipip_entry.parms, and use it to figure out what exactly has
changed.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a bound device of a tunnel netdevice changes VRF, the loopback RIF
that backs the tunnel needs to be updated and existing encapsulating
routes need to be refreshed.

Note that several tunnels can share the same bound device, in which case
all the impacted tunnels need to be updated.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The approach for offloading IP tunnels implemented currently by mlxsw
doesn't allow two tunnels that have the same local IP address in the
same (underlay) VRF. Previously, offloads were introduced on demand as
encap routes were formed. When such a route was created that would cause
offload of a conflicting tunnel, mlxsw_sp_ipip_entry_create() would
detect it and return -EEXIST, which would propagate up and cause FIB
abort.

Now however IPIP entries are created as soon as an offloadable netdevice
is created, and the failure prevents creation of such device.
Furthermore, if the driver is installed at the point where such
conflicting tunnels exist, the failure actually prevents successful
modprobe.

Furthermore, follow-up patches implement handling of NETDEV_CHANGE due
to the local address change. However, NETDEV_CHANGE can't be vetoed. The
failure merely means that the offloads weren't updated, but the change
in Linux configuration is not rolled back. It is thus desirable to have
a robust way of handling these conflicts, which can later be reused for
handling NETDEV_CHANGE as well.

To fix this, when a conflicting tunnel is created, instead of failing,
simply pull the old tunnel to slow path and reject offloading the
new one.

Introduce two functions: mlxsw_sp_ipip_entry_demote_tunnel() and
mlxsw_sp_ipip_demote_tunnel_by_saddr() to handle this. Make them both
public, because they will be useful later on in this patchset.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When trying to determine whether there are other offloaded tunnels with
the same local address, mlxsw_sp_ipip_entry_create() should look for a
tunnel with matching UL protocol, matching saddr, in the same VRF.
However instead of taking into account the UL protocol of the tunnel
netdevice (which mlxsw_sp_ipip_entry_saddr_matches() then compares to
the UL protocol of inspected IPIP entry), it deduces the UL protocol
from the inspected IPIP entry (and that's compared to itself).

This is currently immaterial, because only one tunnel type is offloaded,
and therefore the UL protocol always matches, but introducing support
for a tunnel with IPv6 underlay would uncover this error.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The work that needs to be done to update HW configuration in response to
changes is similar to what __mlxsw_sp_ipip_entry_update_tunnel() already
does, but with a number of twists: each change requires a different
subset of things to happen. Extend the function to support all these
uses, and allow finely-grained configuration of what should happen at
each call through a suite of function arguments.

Publish the updated function to allow use from the spectrum_ipip module.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The work that's done by mlxsw_sp_netdevice_ipip_ol_vrf_event() is a good
basis for a more versatile function that would take care of all sorts of
tunnel updates requests: __mlxsw_sp_ipip_entry_update_tunnel(). Extract
that function. Factor out a helper mlxsw_sp_ipip_entry_ol_lb_update() as
well.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The function mlxsw_sp_rif_create() takes an extack parameter. So far,
for creation of loopback interfaces, NULL was passed. For some events
however the extack can be extracted and passed along. So do that for
NETDEV_CHANGEUPPER handler.

Use the opportunity to update the type of info argument that
mlxsw_sp_netdevice_ipip_ol_event() takes. Follow-up patches will
introduce handling of more changes, and some of them carry an extack as
well, but in an info structure of a different type. Though not strictly
erroneous (the pointer could be cast whichever way), it makes no sense
to pretend the value is always of a certain type, when in fact it isn't.
So change the prototype of the above-mentioned function as well.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The piece of logic to promote decap route, if any, is useful for generic
tunnel updates, not just for handling of NETDEV_UP events on tunnel
interfaces. Extract it to a separate function.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This function only ever returns 0, so don't pretend it returns anything
useful and just make it void.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To implement NETDEV_CHANGE notifications on IP-in-IP tunnels, the
handler needs to figure out what actually changed, to understand how
exactly to update the offloads. It will do so by storing struct
ip_tunnel_parm with previous configuration, and comparing that to the
new version.

To facilitate these comparisons, extract the code that operates on
struct ip_tunnel_parm from the existing accessor functions, and make
those a thin wrapper that extracts tunnel parameters and dispatches.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

These functions ideologically belong to the IPIP module, and some
follow-up work will benefit from their presence there.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some of the code down the road needs this logic as well.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To distinguish between events related to tunnel device itself and its
bound device, rename a number of functions related to handling tunneling
netdevice events to include _ol_ (for "overlay") in the name. That
leaves room in the namespace for underlay-related functions, which would
have _ul_ in the name.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull clk fix from Stephen Boyd:
 "One fix for USB clks on Uniphier PXs3 SoCs"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: uniphier: fix clock data for PXs3

Pull arch/tile fixes from Chris Metcalf:
 "Two one-line bug fixes"

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: Implement ->set_state_oneshot_stopped()
  tile: pass machine size to sparse

Pull SCSI fix from James Bottomley:
 "One minor fix in the error leg of the qla2xxx driver (it oopses the
  system if we get an error trying to start the internal kernel thread).

  The fix is minor because the problem isn't often encountered in the
  field (although it can be induced by inserting the module in a low
  memory environment)"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qla2xxx: Fix oops in qla2x00_probe_one error path

set_state_oneshot_stopped() is called by the clkevt core, when the
next event is required at an expiry time of 'KTIME_MAX'. This normally
happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.

This patch makes the clockevent device to stop on such an event, to
avoid spurious interrupts, as explained by: commit 8fff52fd
("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 4.14.

  This is bigger than I like to send at rc7, but that's at least partly
  because I didn't send any fixes last week. If it wasn't for the IMC
  driver, which is new and getting heavy testing, the diffstat would
  look a bit better. I've also added ftrace on big endian to my test
  suite, so we shouldn't break that again in future.

   - A fix to the handling of misaligned paste instructions (P9 only),
     where a change to a #define has caused the check for the
     instruction to always fail.

   - The preempt handling was unbalanced in the radix THP flush (P9
     only). Though we don't generally use preempt we want to keep it
     working as much as possible.

   - Two fixes for IMC (P9 only), one when booting with restricted
     number of CPUs and one in the error handling when initialisation
     fails due to firmware etc.

   - A revert to fix function_graph on big endian machines, and then a
     rework of the reverted patch to fix kprobes blacklist handling on
     big endian machines.

  Thanks to: Anju T Sudhakar, Guilherme G. Piccoli, Madhavan Srinivasan,
  Naveen N. Rao, Nicholas Piggin, Paul Mackerras"

* tag 'powerpc-4.14-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/perf: Fix core-imc hotplug callback failure during imc initialization
  powerpc/kprobes: Dereference function pointers only if the address does not belong to kernel text
  Revert "powerpc64/elfv1: Only dereference function descriptor for non-text symbols"
  powerpc/64s/radix: Fix preempt imbalance in TLB flush
  powerpc: Fix check for copy/paste instructions in alignment handler
  powerpc/perf: Fix IMC allocation routine

Pull MMC fixes from Ulf Hansson:
 "Fix dw_mmc request timeout issues"

* tag 'mmc-v4.14-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc:
  mmc: dw_mmc: Fix the DTO timeout calculation
  mmc: dw_mmc: Add locking to the CTO timer
  mmc: dw_mmc: Fix the CTO timeout calculation
  mmc: dw_mmc: cancel the CTO timer after a voltage switch

Pull drm fixes from Dave Airlie:

 - one nouveau regression fix

 - some amdgpu fixes for stable to fix hangs on some harvested Polaris
   GPUs

 - a set of KASAN and regression fixes for i915, their CI system seems
   to be working pretty well now.

* tag 'drm-fixes-for-v4.14-rc8' of git://people.freedesktop.org/~airlied/linux:
  drm/amdgpu: allow harvesting check for Polaris VCE
  drm/amdgpu: return -ENOENT from uvd 6.0 early init for harvesting
  drm/i915: Check incoming alignment for unfenced buffers (on i915gm)
  drm/nouveau/kms/nv50: use the correct state for base channel notifier setup
  drm/i915: Hold rcu_read_lock when iterating over the radixtree (vma idr)
  drm/i915: Hold rcu_read_lock when iterating over the radixtree (objects)
  drm/i915/edp: read edp display control registers unconditionally
  drm/i915: Do not rely on wm preservation for ILK watermarks
  drm/i915: Cancel the modeset retry work during modeset cleanup

Pull networking fixes from David Miller:
 "Hopefully this is the last batch of networking fixes for 4.14

  Fingers crossed...

   1) Fix stmmac to use the proper sized OF property read, from Bhadram
      Varka.

   2) Fix use after free in net scheduler tc action code, from Cong
      Wang.

   3) Fix SKB control block mangling in tcp_make_synack().

   4) Use proper locking in fib_dump_info(), from Florian Westphal.

   5) Fix IPG encodings in systemport driver, from Florian Fainelli.

   6) Fix division by zero in NV TCP congestion control module, from
      Konstantin Khlebnikov.

   7) Fix use after free in nf_reject_ipv4, from Tejaswi Tanikella"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: systemport: Correct IPG length settings
  tcp: do not mangle skb->cb[] in tcp_make_synack()
  fib: fib_dump_info can no longer use __in_dev_get_rtnl
  stmmac: use of_property_read_u32 instead of read_u8
  net_sched: hold netns refcnt for each action
  net_sched: acquire RTNL in tc_action_net_exit()
  net: vrf: correct FRA_L3MDEV encode type
  tcp_nv: fix division by zero in tcpnv_acked()
  netfilter: nf_reject_ipv4: Fix use-after-free in send_reset
  netfilter: nft_set_hash: disable fast_ops for 2-len keys

Merge misc fixes from Andrew Morton:
 "7 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, swap: fix race between swap count continuation operations
  mm/huge_memory.c: deposit page table when copying a PMD migration entry
  initramfs: fix initramfs rebuilds w/ compression after disabling
  fs/hugetlbfs/inode.c: fix hwpoison reserve accounting
  ocfs2: fstrim: Fix start offset of first cluster group during fstrim
  mm, /proc/pid/pagemap: fix soft dirty marking for PMD migration entry
  userfaultfd: hugetlbfs: prevent UFFDIO_COPY to fill beyond the end of i_size

MIPS will soon not be a part of Imagination Technologies, and as such
many @imgtec.com email addresses will no longer be valid. This patch
updates the addresses for those who:

 - Have 10 or more patches in mainline authored using an @imgtec.com
   email address, or any patches dated within the past year.

 - Are still with Imagination but leaving as part of the MIPS business
   unit, as determined from an internal email address list.

 - Haven't already updated their email address (ie. JamesH) or expressed
   a desire to be excluded (ie. Maciej).

 - Acked v2 or earlier of this patch, which leaves Deng-Cheng, Matt &
   myself.

New addresses are of the form firstname.lastname@mips.com, and all
verified against an internal email address list.  An entry is added to
.mailmap for each person such that get_maintainer.pl will report the new
addresses rather than @imgtec.com addresses which will soon be dead.

Instances of the affected addresses throughout the tree are then
mechanically replaced with the new @mips.com address.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@mips.com>
Acked-by: Dengcheng Zhu <dengcheng.zhu@mips.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@mips.com>
Acked-by: Matt Redfearn <matt.redfearn@mips.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: trivial@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 890da9cf (Revert "x86: do not use cpufreq_quick_get() for
/proc/cpuinfo "cpu MHz"") is not sufficient to restore the previous
behavior of "cpu MHz" in /proc/cpuinfo on x86 due to some changes
made after the commit it has reverted.

To address this, make the code in question use arch_freq_get_on_cpu()
which also is used by cpufreq for reporting the current frequency of
CPUs and since that function doesn't really depend on cpufreq in any
way, drop the CONFIG_CPU_FREQ dependency for the object file
containing it.

Also refactor arch_freq_get_on_cpu() somewhat to avoid IPIs and
return cached values right away if it is called very often over a
short time (to prevent user space from triggering IPI storms through
it).

Fixes: 890da9cf (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
Cc: stable@kernel.org   # 4.13 - together with 890da9cfSigned-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

One page may store a set of entries of the sis->swap_map
(swap_info_struct->swap_map) in multiple swap clusters.

If some of the entries has sis->swap_map[offset] > SWAP_MAP_MAX,
multiple pages will be used to store the set of entries of the
sis->swap_map.  And the pages are linked with page->lru.  This is called
swap count continuation.  To access the pages which store the set of
entries of the sis->swap_map simultaneously, previously, sis->lock is
used.  But to improve the scalability of __swap_duplicate(), swap
cluster lock may be used in swap_count_continued() now.  This may race
with add_swap_count_continuation() which operates on a nearby swap
cluster, in which the sis->swap_map entries are stored in the same page.

The race can cause wrong swap count in practice, thus cause unfreeable
swap entries or software lockup, etc.

To fix the race, a new spin lock called cont_lock is added to struct
swap_info_struct to protect the swap count continuation page list.  This
is a lock at the swap device level, so the scalability isn't very well.
But it is still much better than the original sis->lock, because it is
only acquired/released when swap count continuation is used.  Which is
considered rare in practice.  If it turns out that the scalability
becomes an issue for some workloads, we can split the lock into some
more fine grained locks.

Link: http://lkml.kernel.org/r/20171017081320.28133-1-ying.huang@intel.com
Fixes: 235b6217 ("mm/swap: add cluster lock")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[4.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>