This device has same vendor and product IDs as G2K devices, but it has
different number of interfaces(4 vs 5) and also different interface
layout where EC20 has QMI on interface 4 instead of 0.

lsusb output:

	Bus 002 Device 003: ID 05c6:9215 Qualcomm, Inc. Acer Gobi 2000
	Device Descriptor:
	  bLength                18
	  bDescriptorType         1
	  bcdUSB               2.00
	  bDeviceClass            0 (Defined at Interface level)
	  bDeviceSubClass         0
	  bDeviceProtocol         0
	  bMaxPacketSize0        64
	  idVendor           0x05c6 Qualcomm, Inc.
	  idProduct          0x9215 Acer Gobi 2000 Wireless Modem
	  bcdDevice            2.32
	  iManufacturer           1 Quectel
	  iProduct                2 Quectel LTE Module
	  iSerial                 0
	  bNumConfigurations      1
	  Configuration Descriptor:
	    bLength                 9
	    bDescriptorType         2
	    wTotalLength          209
	    bNumInterfaces          5
	    bConfigurationValue     1
	    iConfiguration          0
	    bmAttributes         0xa0
	      (Bus Powered)
	      Remote Wakeup
	    MaxPower              500mA
Signed-off-by: NPetr Štetiar <ynezz@true.cz>
Acked-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Johan Hedberg says:

====================
pull request: bluetooth 2015-11-05

The following set of Bluetooth patches would be good to get into 4.4-rc1
if possible:

 - Fix for missing LE CoC parameter validity checks
 - Fix for potential deadlock in btusb
 - Fix for issuing unsupported commands during HCI init

Please let me know if there are any issues pulling. Thanks.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When running "mod X" operation, if X is 0 the filter has to be halt.
Add new test cases to cover A = A mod X if X is 0, and A = A mod 1.

CC: Xi Wang <xi.wang@gmail.com>
CC: Zi Shen Lim <zlim.lnx@gmail.com>
Signed-off-by: NYang Shi <yang.shi@linaro.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NZi Shen Lim <zlim.lnx@gmail.com>
Acked-by: NXi Wang <xi.wang@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

VXLAN may be a loadable module, and this driver cannot be built-in
in that case, or we get a link error:

drivers/built-in.o: In function `__bnxt_open_nic':
drivers/net/ethernet/broadcom/bnxt/bnxt.c:4581: undefined reference to `vxlan_get_rx_port'

This adds a Kconfig dependency that ensures that either VXLAN is
disabled (which the driver handles correctly), or we depend on
VXLAN itself and disallow built-in compilation when VXLAN is
a module.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: c0c050c5 ("bnxt_en: New Broadcom ethernet driver.")
Acked-by: NMichael Chan <mchan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: fee6d4c7 ("net: Add netif_is_l3_slave")
Signed-off-by: NJiri Pirko <jiri@mellanox.com>
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In ipv6_add_dev, when addrconf_sysctl_register fails, we do not clean up
the dev_snmp6 entry that we have already registered for this device.
Call snmp6_unregister_dev in this case.

Fixes: a317a2f1 ("ipv6: fail early when creating netdev named all or default")
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MODE_MF_SI is 9.  We should be testing bit 9 instead of AND 0x9.

Fixes: fe56b9e6 ('qed: Add module with basic common support')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NYuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We check if "p_hwfn" is NULL and then dereference it in the error
handling code.  I read the code and it isn't NULL so let's remove the
check.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NYuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When receiving a connect response we should make sure that the DCID is
within the valid range and that we don't already have another channel
allocated for the same DCID.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The 'dyn_end' value is also a valid CID so it should be included in
the range of values checked.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The core spec defines specific response codes for situations when the
received CID is incorrect. Add the defines for these and return them
as appropriate from the LE Connect Request handler function.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The white list commands might not be implemented if the controller does
not actually support the white list. So check the supported commands
first before issuing these commands. Not supporting the white list is
the same as supporting a white list with zero size.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

commit 8f9d02f4 introduced spinlocks
in btusb_work. This is run in a context of a worqueue and can be interrupted
by hardware irq. If it happens while spinlock is held, we have a deadlock.
Solution is to use _irqsave/_resore version of locking

[  466.460560] =================================
[  466.460565] [ INFO: inconsistent lock state ]
[  466.460572] 4.3.0-rc6+ #1 Tainted: G        W
[  466.460576] ---------------------------------
[  466.460582] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[  466.460589] kworker/0:2/94 [HC0[0]:SC0[0]:HE1:SE1] takes:
[  466.460595]  (&(&data->rxlock)->rlock){?.-...}, at: [<ffffffffa0526923>] btusb_work+0xa3/0x3fd [btusb]
[  466.460621] {IN-HARDIRQ-W} state was registered at:
[  466.460625]   [<ffffffff811021b5>] __lock_acquire+0xc45/0x1e80
[  466.460638]   [<ffffffff811040d5>] lock_acquire+0xe5/0x1f0
[  466.460646]   [<ffffffff8182f108>] _raw_spin_lock+0x38/0x50
[  466.460657]   [<ffffffffa0525448>] btusb_recv_intr+0x38/0x170 [btusb]
[  466.460668]   [<ffffffffa0525626>] btusb_intr_complete+0xa6/0x130 [btusb]
[  466.460679]   [<ffffffff815d8f1e>] __usb_hcd_giveback_urb+0x8e/0x160
[  466.460690]   [<ffffffff815d911f>] usb_hcd_giveback_urb+0x3f/0x120
[  466.460698]   [<ffffffff81606e4d>] uhci_giveback_urb+0xad/0x280
[  466.460706]   [<ffffffff81608f64>] uhci_scan_schedule.part.33+0x6b4/0xbe0
[  466.460714]   [<ffffffff81609b50>] uhci_irq+0xd0/0x180
[  466.460722]   [<ffffffff815d8296>] usb_hcd_irq+0x26/0x40
[  466.460729]   [<ffffffff81117d40>] handle_irq_event_percpu+0x40/0x300
[  466.460739]   [<ffffffff81118040>] handle_irq_event+0x40/0x60
[  466.460746]   [<ffffffff8111af39>] handle_fasteoi_irq+0x89/0x150
[  466.460754]   [<ffffffff8101e0f3>] handle_irq+0x73/0x120
[  466.460763]   [<ffffffff81832f11>] do_IRQ+0x61/0x120
[  466.460772]   [<ffffffff8183084c>] ret_from_intr+0x0/0x31
[  466.460780]   [<ffffffff81697a77>] cpuidle_enter+0x17/0x20
[  466.460790]   [<ffffffff810f62c2>] call_cpuidle+0x32/0x60
[  466.460800]   [<ffffffff810f65a8>] cpu_startup_entry+0x2b8/0x3f0
[  466.460807]   [<ffffffff818214ca>] rest_init+0x13a/0x140
[  466.460817]   [<ffffffff81f76029>] start_kernel+0x4a3/0x4c4
[  466.460827]   [<ffffffff81f75339>] x86_64_start_reservations+0x2a/0x2c
[  466.460837]   [<ffffffff81f75485>] x86_64_start_kernel+0x14a/0x16d
[  466.460846] irq event stamp: 754913
[  466.460851] hardirqs last  enabled at (754913): [<ffffffff8182f4cc>] _raw_spin_unlock_irq+0x2c/0x40
[  466.460861] hardirqs last disabled at (754912): [<ffffffff8182f28d>] _raw_spin_lock_irq+0x1d/0x60
[  466.460869] softirqs last  enabled at (753024): [<ffffffff810aeaa0>] __do_softirq+0x380/0x490
[  466.460880] softirqs last disabled at (753009): [<ffffffff810aedef>] irq_exit+0x10f/0x120
[  466.460888]
               other info that might help us debug this:
[  466.460894]  Possible unsafe locking scenario:

[  466.460899]        CPU0
[  466.460903]        ----
[  466.460907]   lock(&(&data->rxlock)->rlock);
[  466.460915]   <Interrupt>
[  466.460918]     lock(&(&data->rxlock)->rlock);
[  466.460926]
                *** DEADLOCK ***

[  466.460935] 2 locks held by kworker/0:2/94:
[  466.460939]  #0:  ("events"){.+.+.+}, at: [<ffffffff810c69bb>] process_one_work+0x16b/0x660
[  466.460958]  #1:  ((&data->work)){+.+...}, at: [<ffffffff810c69bb>] process_one_work+0x16b/0x660
[  466.460974]
Signed-off-by: NKuba Pawlak <kubax.t.pawlak@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When a listen socket enqueues a connection for userspace to accept(),
the sk->sk_data_ready() callback should be invoked.  In-kernel socket
users rely on this callback to detect when incoming connections are
available.

Currently the sk->sk_state_change() callback is invoked by
vmci_transport.c.  This happens to work for userspace applications since
sk->sk_state_change = sock_def_wakeup() and sk->sk_data_ready =
sock_def_readable() both wake up the accept() waiter.  In-kernel socket
users, on the other hand, fail to detect incoming connections.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In tun_dst_unclone() the return value of skb_metadata_dst() is checked
for being NULL after it is dereferenced. Fix this by moving the
dereference after the NULL check.

Found by the Coverity scanner (CID 1338068).

Fixes: fc4099f1 ("openvswitch: Fix egress tunnel info.")
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: NTobias Klauser <tklauser@distanz.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With moving netdev_sync_lower_features() after the .ndo_set_features
calls, I neglected to verify that devices added *after* a flag had been
disabled on an upper device were properly added with that flag disabled as
well. This currently happens, because we exit __netdev_update_features()
when we see dev->features == features for the upper dev. We can retain the
optimization of leaving without calling .ndo_set_features with a bit of
tweaking and a goto here.

Fixes: fd867d51 ("net/core: generic support for disabling netdev features down stack")
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <gospo@cumulusnetworks.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Nikolay Aleksandrov <razor@blackwall.org>
CC: Michal Kubecek <mkubecek@suse.cz>
CC: Alexander Duyck <alexander.duyck@gmail.com>
CC: netdev@vger.kernel.org
Reported-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A bug report (https://bugzilla.kernel.org/show_bug.cgi?id=107071) noted
that the follwoing ip command is failing with v4.3:

    $ ip route add 10.248.5.0/24 dev bond0.250 table vlan_250 src 10.248.5.154
    RTNETLINK answers: Invalid argument

021dd3b8 changed the lookup of the given preferred source address to
use the table id passed in, but this assumes the local entries are in the
given table which is not necessarily true for non-VRF use cases. When
validating the preferred source fallback to the local table on failure.

Fixes: 021dd3b8 ("net: Add routes to the table associated with the device")
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sasha reported the following lockdep warning:

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(sk_lock-AF_INET);
                                lock(rtnl_mutex);
                                lock(sk_lock-AF_INET);
   lock(rtnl_mutex);

This is due to that for IP_MSFILTER and MCAST_MSFILTER, we take
rtnl lock before the socket lock in setsockopt() path, but take
the socket lock before rtnl lock in getsockopt() path. All the
rest optnames are setsockopt()-only.

Fix this by aligning the getsockopt() path with the setsockopt()
path, so that all mcast socket path would be locked in the same
order.

Note, IPv6 part is different where rtnl lock is not held.

Fixes: 54ff9ef3 ("ipv4, ipv6: kill ip_mc_{join, leave}_group and ipv6_sock_mc_{join, drop}")
Reported-by: NSasha Levin <sasha.levin@oracle.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This fixes the following lockdep warning:

 [ INFO: inconsistent lock state ]
 4.3.0-rc7+ #1197 Not tainted
 ---------------------------------
 inconsistent {IN-SOFTIRQ-R} -> {SOFTIRQ-ON-W} usage.
 sysctl/1019 [HC0[0]:SC0[0]:HE1:SE1] takes:
  (&(&net->ipv4.ip_local_ports.lock)->seqcount){+.+-..}, at: [<ffffffff81921de7>] ipv4_local_port_range+0xb4/0x12a
 {IN-SOFTIRQ-R} state was registered at:
   [<ffffffff810bd682>] __lock_acquire+0x2f6/0xdf0
   [<ffffffff810be6d5>] lock_acquire+0x11c/0x1a4
   [<ffffffff818e599c>] inet_get_local_port_range+0x4e/0xae
   [<ffffffff8166e8e3>] udp_flow_src_port.constprop.40+0x23/0x116
   [<ffffffff81671cb9>] vxlan_xmit_one+0x219/0xa6a
   [<ffffffff81672f75>] vxlan_xmit+0xa6b/0xaa5
   [<ffffffff817f2deb>] dev_hard_start_xmit+0x2ae/0x465
   [<ffffffff817f35ed>] __dev_queue_xmit+0x531/0x633
   [<ffffffff817f3702>] dev_queue_xmit_sk+0x13/0x15
   [<ffffffff818004a5>] neigh_resolve_output+0x12f/0x14d
   [<ffffffff81959cfa>] ip6_finish_output2+0x344/0x39f
   [<ffffffff8195bf58>] ip6_finish_output+0x88/0x8e
   [<ffffffff8195bfef>] ip6_output+0x91/0xe5
   [<ffffffff819792ae>] dst_output_sk+0x47/0x4c
   [<ffffffff81979392>] NF_HOOK_THRESH.constprop.30+0x38/0x82
   [<ffffffff8197981e>] mld_sendpack+0x189/0x266
   [<ffffffff8197b28b>] mld_ifc_timer_expire+0x1ef/0x223
   [<ffffffff810de581>] call_timer_fn+0xfb/0x28c
   [<ffffffff810ded1e>] run_timer_softirq+0x1c7/0x1f1

Fixes: b8f1a556 ("udp: Add function to make source port for UDP tunnels")
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While the ring allocation is done by a single function, sh_eth_ring_init(),
the ring deallocation was split into two functions (almost always called
one after the other) for no good reason. Merge  sh_eth_free_dma_buffer()
into sh_eth_ring_free() which allows us  to save space not only on the
direct calls  of the former function but also on the sh_eth_ring_init()'s
simplified error path...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 'ret' local variable in sh_eth_ring_init() serves no useful purpose as
the only  values it gets assigned are 0 and -ENOMEM both of which could be
returned directly...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for a fixed-link devicetree sub-node in case the the
cpsw MAC is directly connected to a non-mdio PHY/device.
Signed-off-by: NMarkus Brunner <systemprogrammierung.brunner@gmail.com>
Acked-by: NMugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Conflicts:
	net/netfilter/xt_TEE.c

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Fix crash when TEE target is used with no --oif, from Eric Dumazet.

2) Oneliner to fix a crash on the redirect traffic to localhost
   infrastructure when interface has not yet an address, from
   Munehisa Kamata.

3) Oneliner not to request module all the time from nfnetlink due to
   wrong type value, from Florian Westphal.

I'll make sure these patches 1 and 2 hit -stable.
====================

The conflict in net/netfilter/xt_TEE.c was minor, a change
to the 'oif' selection overlapping a function signature
change for the nf_dup_ipv{4,6}() routines.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull IDE fixlet from David Miller:
 "Just a y2038 fix to the pdc202xx_new IDE driver"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide:
  ide: pdc202xx_new: Replace timeval with ktime_t

Pull networking updates from David Miller:

Changes of note:

 1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell.

 2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from
    David Ahern.

 3) Allow the user to ask for the statistics to be filtered out of
    ipv4/ipv6 address netlink dumps.  From Sowmini Varadhan.

 4) More work to pass the network namespace context around deep into
    various packet path APIs, starting with the netfilter hooks.  From
    Eric W Biederman.

 5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas
    Richter.

 6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng.

 7) Support Very High Throughput in wireless MESH code, from Bob
    Copeland.

 8) Allow setting the ageing_time in switchdev/rocker.  From Scott
    Feldman.

 9) Properly autoload L2TP type modules, from Stephen Hemminger.

10) Fix and enable offload features by default in 8139cp driver, from
    David Woodhouse.

11) Support both ipv4 and ipv6 sockets in a single vxlan device, from
    Jiri Benc.

12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning
    Opstad.

13) Fix IPSEC flowcache overflows on large systems, from Steffen
    Klassert.

14) Convert bridging to track VLANs using rhashtable entries rather than
    a bitmap.  From Nikolay Aleksandrov.

15) Make TCP listener handling completely lockless, this is a major
    accomplishment.  Incoming request sockets now live in the
    established hash table just like any other socket too.

    From Eric Dumazet.

15) Provide more bridging attributes to netlink, from Nikolay
    Aleksandrov.

16) Use hash based algorithm for ipv4 multipath routing, this was very
    long overdue.  From Peter Nørlund.

17) Several y2038 cures, mostly avoiding timespec.  From Arnd Bergmann.

18) Allow non-root execution of EBPF programs, from Alexei Starovoitov.

19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet.  This
    influences the port binding selection logic used by SO_REUSEPORT.

20) Add ipv6 support to VRF, from David Ahern.

21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko.

22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen.

23) Implement RACK loss recovery in TCP, from Yuchung Cheng.

24) Support multipath routes in MPLS, from Roopa Prabhu.

25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric
    Dumazet.

26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and
    Sudarsana Kalluru.

27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic
    Sowa.

28) Support ipv6 geneve tunnels, from John W Linville.

29) Add flood control support to switchdev layer, from Ido Schimmel.

30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from
    Hannes Frederic Sowa.

31) Support persistent maps and progs in bpf, from Daniel Borkmann.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits)
  sh_eth: use DMA barriers
  switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion
  net: sched: kill dead code in sch_choke.c
  irda: Delete an unnecessary check before the function call "irlmp_unregister_service"
  net: dsa: mv88e6xxx: include DSA ports in VLANs
  net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports
  net/core: fix for_each_netdev_feature
  vlan: Invoke driver vlan hooks only if device is present
  arcnet/com20020: add LEDS_CLASS dependency
  bpf, verifier: annotate verbose printer with __printf
  dp83640: Only wait for timestamps for packets with timestamping enabled.
  ptp: Change ptp_class to a proper bitmask
  dp83640: Prune rx timestamp list before reading from it
  dp83640: Delay scheduled work.
  dp83640: Include hash in timestamp/packet matching
  ipv6: fix tunnel error handling
  net/mlx5e: Fix LSO vlan insertion
  net/mlx5e: Re-eanble client vlan TX acceleration
  net/mlx5e: Return error in case mlx5e_set_features() fails
  net/mlx5e: Don't allow more than max supported channels
  ...

Pull crypto update from Herbert Xu:
 "API:

   - Add support for cipher output IVs in testmgr
   - Add missing crypto_ahash_blocksize helper
   - Mark authenc and des ciphers as not allowed under FIPS.

Algorithms:

   - Add CRC support to 842 compression
   - Add keywrap algorithm
   - A number of changes to the akcipher interface:
      + Separate functions for setting public/private keys.
      + Use SG lists.

Drivers:

   - Add Intel SHA Extension optimised SHA1 and SHA256
   - Use dma_map_sg instead of custom functions in crypto drivers
   - Add support for STM32 RNG
   - Add support for ST RNG
   - Add Device Tree support to exynos RNG driver
   - Add support for mxs-dcp crypto device on MX6SL
   - Add xts(aes) support to caam
   - Add ctr(aes) and xts(aes) support to qat
   - A large set of fixes from Russell King for the marvell/cesa driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (115 commits)
  crypto: asymmetric_keys - Fix unaligned access in x509_get_sig_params()
  crypto: akcipher - Don't #include crypto/public_key.h as the contents aren't used
  hwrng: exynos - Add Device Tree support
  hwrng: exynos - Fix missing configuration after suspend to RAM
  hwrng: exynos - Add timeout for waiting on init done
  dt-bindings: rng: Describe Exynos4 PRNG bindings
  crypto: marvell/cesa - use __le32 for hardware descriptors
  crypto: marvell/cesa - fix missing cpu_to_le32() in mv_cesa_dma_add_op()
  crypto: marvell/cesa - use memcpy_fromio()/memcpy_toio()
  crypto: marvell/cesa - use gfp_t for gfp flags
  crypto: marvell/cesa - use dma_addr_t for cur_dma
  crypto: marvell/cesa - use readl_relaxed()/writel_relaxed()
  crypto: caam - fix indentation of close braces
  crypto: caam - only export the state we really need to export
  crypto: caam - fix non-block aligned hash calculation
  crypto: caam - avoid needlessly saving and restoring caam_hash_ctx
  crypto: caam - print errno code when hash registration fails
  crypto: marvell/cesa - fix memory leak
  crypto: marvell/cesa - fix first-fragment handling in mv_cesa_ahash_dma_last_req()
  crypto: marvell/cesa - rearrange handling for sw padded hashes
  ...

Pull x86 platform changes from Ingo Molnar:
 "Misc updates to the Intel MID and SGI UV platforms"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/intel-mid: Make intel_mid_ops static
  arch/x86/intel-mid: Use kmemdup rather than duplicating its implementation
  x86/platform/uv: Implement simple dump failover if kdump fails
  x86/platform/uv: Insert per_cpu accessor function on uv_hub_nmi

Pull x86 mm changes from Ingo Molnar:
 "The main changes are: continued PAT work by Toshi Kani, plus a new
  boot time warning about insecure RWX kernel mappings, by Stephen
  Smalley.

  The new CONFIG_DEBUG_WX=y warning is marked default-y if
  CONFIG_DEBUG_RODATA=y is already eanbled, as a special exception, as
  these bugs are hard to notice and this check already found several
  live bugs"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Warn on W^X mappings
  x86/mm: Fix no-change case in try_preserve_large_page()
  x86/mm: Fix __split_large_page() to handle large PAT bit
  x86/mm: Fix try_preserve_large_page() to handle large PAT bit
  x86/mm: Fix gup_huge_p?d() to handle large PAT bit
  x86/mm: Fix slow_virt_to_phys() to handle large PAT bit
  x86/mm: Fix page table dump to show PAT bit
  x86/asm: Add pud_pgprot() and pmd_pgprot()
  x86/asm: Fix pud/pmd interfaces to handle large PAT bit
  x86/asm: Add pud/pmd mask interfaces to handle large PAT bit
  x86/asm: Move PUD_PAGE macros to page_types.h
  x86/vdso32: Define PGTABLE_LEVELS to 32bit VDSO

Pull x86 sigcontext header cleanups from Ingo Molnar:
 "This series reorganizes and cleans up various aspects of the main
  sigcontext UAPI headers, such as unifying the data structures and
  updating/adding lots of comments to explain all the ABI details and
  quirks.  The headers can now also be built in user-space standalone"

* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/headers: Clean up too long lines
  x86/headers: Remove <asm/sigcontext.h> references on the kernel side
  x86/headers: Remove direct sigcontext32.h uses
  x86/headers: Convert sigcontext_ia32 uses to sigcontext_32
  x86/headers: Unify 'struct sigcontext_ia32' and 'struct sigcontext_32'
  x86/headers: Make sigcontext pointers bit independent
  x86/headers: Move the 'struct sigcontext' definitions into the UAPI header
  x86/headers: Clean up the kernel's struct sigcontext types to be ABI-clean
  x86/headers: Convert uses of _fpstate_ia32 to _fpstate_32
  x86/headers: Unify 'struct _fpstate_ia32' and i386 struct _fpstate
  x86/headers: Unify register type definitions between 32-bit compat and i386
  x86/headers: Use ABI types consistently in sigcontext*.h
  x86/headers: Separate out legacy user-space structure definitions
  x86/headers: Clean up and better document uapi/asm/sigcontext.h
  x86/headers: Clean up uapi/asm/sigcontext32.h
  x86/headers: Fix (old) header file dependency bug in uapi/asm/sigcontext32.h

Pull x86 fpu changes from Ingo Molnar:
 "There are two main areas of changes:

   - Rework of the extended FPU state code to robustify the kernel's
     usage of cpuid provided xstate sizes - and related changes (Dave
     Hansen)"

   - math emulation enhancements: new modern FPU instructions support,
     with testcases, plus cleanups (Denys Vlasnko)"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/fpu: Fixup uninitialized feature_name warning
  x86/fpu/math-emu: Add support for FISTTP instructions
  x86/fpu/math-emu, selftests: Add test for FISTTP instructions
  x86/fpu/math-emu: Add support for FCMOVcc insns
  x86/fpu/math-emu: Add support for F[U]COMI[P] insns
  x86/fpu/math-emu: Remove define layer for undocumented opcodes
  x86/fpu/math-emu, selftests: Add tests for FCMOV and FCOMI insns
  x86/fpu/math-emu: Remove !NO_UNDOC_CODE
  x86/fpu: Check CPU-provided sizes against struct declarations
  x86/fpu: Check to ensure increasing-offset xstate offsets
  x86/fpu: Correct and check XSAVE xstate size calculations
  x86/fpu: Add C structures for AVX-512 state components
  x86/fpu: Rework YMM definition
  x86/fpu/mpx: Rework MPX 'xstate' types
  x86/fpu: Add xfeature_enabled() helper instead of test_bit()
  x86/fpu: Remove 'xfeature_nr'
  x86/fpu: Rework XSTATE_* macros to remove magic '2'
  x86/fpu: Rename XFEATURES_NR_MAX
  x86/fpu: Rename XSAVE macros
  x86/fpu: Remove partial LWP support definitions
  ...

Pull x86 kgdb fixlet from Ingo Molnar:
 "A single debugging related commit: compress the memory usage of a kgdb
  data structure"

* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kgdb: Replace bool_int_array[NR_CPUS] with bitmap

Pull x86 cpu changes from Ingo Molnar:
 "Two changes in this cycle: a Kconfig help text enhancement, and an AMD
  CLZERO instruction capability detection and enumeration"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add CLZERO detection
  x86/Kconfig/cpus: Fix/complete CPU type help texts

Pull x86 cleanups from Ingo Molnar:
 "An early_printk cleanup plus deinlining enhancements"

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/early_printk: Set __iomem address space for IO
  x86/signal: Deinline get_sigframe, save 240 bytes
  x86: Deinline early_console_register, save 403 bytes
  x86/e820: Deinline e820_type_to_string, save 126 bytes

Pull x86 boot cleanup from Ingo Molnar:
 "A single commit: remove an obsolete kcrash boot flag"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kexec: Remove obsolete 'in_crash_kexec' flag

Pull x86 asm changes from Ingo Molnar:
 "The main change in this cycle is another step in the big x86 system
  call interface rework by Andy Lutomirski, which moves most of the low
  level x86 entry code from assembly to C, for all syscall entries
  except native 64-bit system calls:

    arch/x86/entry/entry_32.S        | 182 ++++------
    arch/x86/entry/entry_64_compat.S | 547 ++++++++-----------------------
    194 insertions(+), 535 deletions(-)

  ... our hope is that the final remaining step (converting native
  64-bit system calls) will be less painful as all the previous steps,
  given that most of the legacies and quirks are concentrated around
  native 32-bit and compat environments"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/entry/32: Fix FS and GS restore in opportunistic SYSEXIT
  x86/entry/32: Fix entry_INT80_32() to expect interrupts to be on
  um/x86: Fix build after x86 syscall changes
  x86/asm: Remove the xyz_cfi macros from dwarf2.h
  selftests/x86: Style fixes for the 'unwind_vdso' test
  x86/entry/64/compat: Document sysenter_fix_flags's reason for existence
  x86/entry: Split and inline syscall_return_slowpath()
  x86/entry: Split and inline prepare_exit_to_usermode()
  x86/entry: Use pt_regs_to_thread_info() in syscall entry tracing
  x86/entry: Hide two syscall entry assertions behind CONFIG_DEBUG_ENTRY
  x86/entry: Micro-optimize compat fast syscall arg fetch
  x86/entry: Force inlining of 32-bit syscall code
  x86/entry: Make irqs_disabled checks in exit code depend on lockdep
  x86/entry: Remove unnecessary IRQ twiddling in fast 32-bit syscalls
  x86/asm: Remove thread_info.sysenter_return
  x86/entry/32: Re-implement SYSENTER using the new C path
  x86/entry/32: Switch INT80 to the new C syscall path
  x86/entry/32: Open-code return tracking from fork and kthreads
  x86/entry/compat: Implement opportunistic SYSRETL for compat syscalls
  x86/vdso/compat: Wire up SYSENTER and SYSCSALL for compat userspace
  ...

Pull x86 apic changes from Ingo Molnar:
 "The main changes in this cycle were:

   - Numachip updates: new hardware support, fixes and cleanups.
     (Daniel J Blueman)

   - misc smaller cleanups and fixlets"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/io_apic: Make eoi_ioapic_pin() static
  x86/irq: Drop unlikely before IS_ERR_OR_NULL
  x86/x2apic: Make stub functions available even if !CONFIG_X86_LOCAL_APIC
  x86/apic: Deinline various functions
  x86/numachip: Fix timer build conflict
  x86/numachip: Introduce Numachip2 timer mechanisms
  x86/numachip: Add Numachip IPI optimisations
  x86/numachip: Add Numachip2 APIC support
  x86/numachip: Cleanup Numachip support

Pull scheduler changes from Ingo Molnar:
 "The main changes in this cycle were:

   - sched/fair load tracking fixes and cleanups (Byungchul Park)

   - Make load tracking frequency scale invariant (Dietmar Eggemann)

   - sched/deadline updates (Juri Lelli)

   - stop machine fixes, cleanups and enhancements for bugs triggered by
     CPU hotplug stress testing (Oleg Nesterov)

   - scheduler preemption code rework: remove PREEMPT_ACTIVE and related
     cleanups (Peter Zijlstra)

   - Rework the sched_info::run_delay code to fix races (Peter Zijlstra)

   - Optimize per entity utilization tracking (Peter Zijlstra)

   - ... misc other fixes, cleanups and smaller updates"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
  sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS
  sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
  sched: Start stopper early
  stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
  stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
  stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled
  stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
  stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
  sched/x86: Fix typo in __switch_to() comments
  sched/core: Remove a parameter in the migrate_task_rq() function
  sched/core: Drop unlikely behind BUG_ON()
  sched/core: Fix task and run queue sched_info::run_delay inconsistencies
  sched/numa: Fix task_tick_fair() from disabling numa_balancing
  sched/core: Add preempt_count invariant check
  sched/core: More notrace annotations
  sched/core: Kill PREEMPT_ACTIVE
  sched/core, sched/x86: Kill thread_info::saved_preempt_count
  sched/core: Simplify preempt_count tests
  sched/core: Robustify preemption leak checks
  sched/core: Stop setting PREEMPT_ACTIVE
  ...

Pull RAS changes from Ingo Molnar:
 "The main system reliability related changes were from x86, but also
  some generic RAS changes:

   - AMD MCE error injection subsystem enhancements.  (Aravind
     Gopalakrishnan)

   - Fix MCE and CPU hotplug interaction bug.  (Ashok Raj)

   - kcrash bootup robustness fix.  (Baoquan He)

   - kcrash cleanups.  (Borislav Petkov)

   - x86 microcode driver rework: simplify it by unmodularizing it and
     other cleanups.  (Borislav Petkov)"

* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/mce: Add a default case to the switch in __mcheck_cpu_ancient_init()
  x86/mce: Add a Scalable MCA vendor flags bit
  MAINTAINERS: Unify the microcode driver section
  x86/microcode/intel: Move #ifdef DEBUG inside the function
  x86/microcode/amd: Remove maintainers from comments
  x86/microcode: Remove modularization leftovers
  x86/microcode: Merge the early microcode loader
  x86/microcode: Unmodularize the microcode driver
  x86/mce: Fix thermal throttling reporting after kexec
  kexec/crash: Say which char is the unrecognized
  x86/setup/crash: Check memblock_reserve() retval
  x86/setup/crash: Cleanup some more
  x86/setup/crash: Remove alignment variable
  x86/setup: Cleanup crashkernel reservation functions
  x86/amd_nb, EDAC: Rename amd_get_node_id()
  x86/setup: Do not reserve crashkernel high memory if low reservation failed
  x86/microcode/amd: Do not overwrite final patch levels
  x86/microcode/amd: Extract current patch level read to a function
  x86/ras/mce_amd_inj: Inject bank 4 errors on the NBC
  x86/ras/mce_amd_inj: Trigger deferred and thresholding errors interrupts
  ...

Pull perf updates from Ingo Molnar:
 "Kernel side changes:

   - Improve accuracy of perf/sched clock on x86.  (Adrian Hunter)

   - Intel DS and BTS updates.  (Alexander Shishkin)

   - Intel cstate PMU support.  (Kan Liang)

   - Add group read support to perf_event_read().  (Peter Zijlstra)

   - Branch call hardware sampling support, implemented on x86 and
     PowerPC.  (Stephane Eranian)

   - Event groups transactional interface enhancements.  (Sukadev
     Bhattiprolu)

   - Enable proper x86/intel/uncore PMU support on multi-segment PCI
     systems.  (Taku Izumi)

   - ... misc fixes and cleanups.

  The perf tooling team was very busy again with 200+ commits, the full
  diff doesn't fit into lkml size limits.  Here's an (incomplete) list
  of the tooling highlights:

  New features:

   - Change the default event used in all tools (record/top): use the
     most precise "cycles" hw counter available, i.e. when the user
     doesn't specify any event, it will try using cycles:ppp, cycles:pp,
     etc and fall back transparently until it finds a working counter.
     (Arnaldo Carvalho de Melo)

   - Integration of perf with eBPF that, given an eBPF .c source file
     (or .o file built for the 'bpf' target with clang), will get it
     automatically built, validated and loaded into the kernel via the
     sys_bpf syscall, which can then be used and seen using 'perf trace'
     and other tools.

     (Wang Nan)

  Various user interface improvements:

   - Automatic pager invocation on long help output.  (Namhyung Kim)

   - Search for more options when passing args to -h, e.g.: (Arnaldo
     Carvalho de Melo)

        $ perf report -h interface

        Usage: perf report [<options>]

         --gtk    Use the GTK2 interface
         --stdio  Use the stdio interface
         --tui    Use the TUI interface

   - Show ordered command line options when -h is used or when an
     unknown option is specified.  (Arnaldo Carvalho de Melo)

   - If options are passed after -h, show just its descriptions, not all
     options.  (Arnaldo Carvalho de Melo)

   - Implement column based horizontal scrolling in the hists browser
     (top, report), making it possible to use the TUI for things like
     'perf mem report' where there are many more columns than can fit in
     a terminal.  (Arnaldo Carvalho de Melo)

   - Enhance the error reporting of tracepoint event parsing, e.g.:

       $ oldperf record -e sched:sched_switc usleep 1
       event syntax error: 'sched:sched_switc'
                            \___ unknown tracepoint
       Run 'perf list' for a list of valid events

     Now we get the much nicer:

       $ perf record -e sched:sched_switc ls
       event syntax error: 'sched:sched_switc'
                            \___ can't access trace events

       Error: No permissions to read /sys/kernel/debug/tracing/events/sched/sched_switc
       Hint:  Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'

     And after we have those mount point permissions fixed:

       $ perf record -e sched:sched_switc ls
       event syntax error: 'sched:sched_switc'
                            \___ unknown tracepoint

       Error: File /sys/kernel/debug/tracing/events/sched/sched_switc not found.
       Hint:  Perhaps this kernel misses some CONFIG_ setting to enable this feature?.

     I.e.  basically now the event parsing routing uses the strerror_open()
     routines introduced by and used in 'perf trace' work.  (Jiri Olsa)

   - Fail properly when pattern matching fails to find a tracepoint,
     i.e. '-e non:existent' was being correctly handled, with a proper
     error message about that not being a valid event, but '-e
     non:existent*' wasn't, fix it.  (Jiri Olsa)

   - Do event name substring search as last resort in 'perf list'.
     (Arnaldo Carvalho de Melo)

     E.g.:

       # perf list clock

       List of pre-defined events (to be used in -e):

        cpu-clock                                          [Software event]
        task-clock                                         [Software event]

        uncore_cbox_0/clockticks/                          [Kernel PMU event]
        uncore_cbox_1/clockticks/                          [Kernel PMU event]

        kvm:kvm_pvclock_update                             [Tracepoint event]
        kvm:kvm_update_master_clock                        [Tracepoint event]
        power:clock_disable                                [Tracepoint event]
        power:clock_enable                                 [Tracepoint event]
        power:clock_set_rate                               [Tracepoint event]
        syscalls:sys_enter_clock_adjtime                   [Tracepoint event]
        syscalls:sys_enter_clock_getres                    [Tracepoint event]
        syscalls:sys_enter_clock_gettime                   [Tracepoint event]
        syscalls:sys_enter_clock_nanosleep                 [Tracepoint event]
        syscalls:sys_enter_clock_settime                   [Tracepoint event]
        syscalls:sys_exit_clock_adjtime                    [Tracepoint event]
        syscalls:sys_exit_clock_getres                     [Tracepoint event]
        syscalls:sys_exit_clock_gettime                    [Tracepoint event]
        syscalls:sys_exit_clock_nanosleep                  [Tracepoint event]
        syscalls:sys_exit_clock_settime                    [Tracepoint event]

  Intel PT hardware tracing enhancements:

   - Accept a zero --itrace period, meaning "as often as possible".  In
     the case of Intel PT that is the same as a period of 1 and a unit
     of 'instructions' (i.e.  --itrace=i1i).  (Adrian Hunter)

   - Harmonize itrace's synthesized callchains with the existing
     --max-stack tool option.  (Adrian Hunter)

   - Allow time to be displayed in nanoseconds in 'perf script'.
     (Adrian Hunter)

   - Fix potential infinite loop when handling Intel PT timestamps.
     (Adrian Hunter)

   - Slighly improve Intel PT debug logging.  (Adrian Hunter)

   - Warn when AUX data has been lost, just like when processing
     PERF_RECORD_LOST.  (Adrian Hunter)

   - Further document export-to-postgresql.py script.  (Adrian Hunter)

   - Add option to synthesize branch stack from auxtrace data.  (Adrian
     Hunter)

  Misc notable changes:

   - Switch the default callchain output mode to 'graph,0.5,caller', to
     make it look like the default for other tools, reducing the
     learning curve for people used to 'caller' based viewing.  (Arnaldo
     Carvalho de Melo)

   - various call chain usability enhancements.  (Namhyung Kim)

   - Introduce the 'P' event modifier, meaning 'max precision level,
     please', i.e.:

        $ perf record -e cycles:P usleep 1

     Is now similar to:

        $ perf record usleep 1

     Useful, for instance, when specifying multiple events.  (Jiri Olsa)

   - Add 'socket' sort entry, to sort by the processor socket in 'perf
     top' and 'perf report'.  (Kan Liang)

   - Introduce --socket-filter to 'perf report', for filtering by
     processor socket.  (Kan Liang)

   - Add new "Zoom into Processor Socket" operation in the perf hists
     browser, used in 'perf top' and 'perf report'.  (Kan Liang)

   - Allow probing on kmodules without DWARF.  (Masami Hiramatsu)

   - Fix 'perf probe -l' for probes added to kernel module functions.
     (Masami Hiramatsu)

   - Preparatory work for the 'perf stat record' feature that will allow
     generating perf.data files with counting data in addition to the
     sampling mode we have now (Jiri Olsa)

   - Update libtraceevent KVM plugin.  (Paolo Bonzini)

   - ... plus lots of other enhancements that I failed to list properly,
     by: Adrian Hunter, Alexander Shishkin, Andi Kleen, Andrzej Hajda,
     Arnaldo Carvalho de Melo, Dima Kogan, Don Zickus, Geliang Tang, He
     Kuang, Huaitong Han, Ingo Molnar, Jan Stancek, Jiri Olsa, Kan
     Liang, Kirill Tkhai, Masami Hiramatsu, Matt Fleming, Namhyung Kim,
     Paolo Bonzini, Peter Zijlstra, Rabin Vincent, Scott Wood, Stephane
     Eranian, Sukadev Bhattiprolu, Taku Izumi, Vaishali Thakkar, Wang
     Nan, Yang Shi and Yunlong Song"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (260 commits)
  perf unwind: Pass symbol source to libunwind
  tools build: Fix libiberty feature detection
  perf tools: Compile scriptlets to BPF objects when passing '.c' to --event
  perf record: Add clang options for compiling BPF scripts
  perf bpf: Attach eBPF filter to perf event
  perf tools: Make sure fixdep is built before libbpf
  perf script: Enable printing of branch stack
  perf trace: Add cmd string table to decode sys_bpf first arg
  perf bpf: Collect perf_evsel in BPF object files
  perf tools: Load eBPF object into kernel
  perf tools: Create probe points for BPF programs
  perf tools: Enable passing bpf object file to --event
  perf ebpf: Add the libbpf glue
  perf tools: Make perf depend on libbpf
  perf symbols: Fix endless loop in dso__split_kallsyms_for_kcore
  perf tools: Enable pre-event inherit setting by config terms
  perf symbols: we can now read separate debug-info files based on a build ID
  perf symbols: Fix type error when reading a build-id
  perf tools: Search for more options when passing args to -h
  perf stat: Cache aggregated map entries in extra cpumap
  ...

This seems to be a mis-reading of how alpha memory ordering works, and
is not backed up by the alpha architecture manual.  The helper functions
don't do anything special on any other architectures, and the arguments
that support them being safe on other architectures also argue that they
are safe on alpha.

Basically, the "control dependency" is between a previous read and a
subsequent write that is dependent on the value read.  Even if the
subsequent write is actually done speculatively, there is no way that
such a speculative write could be made visible to other cpu's until it
has been committed, which requires validating the speculation.

Note that most weakely ordered architectures (very much including alpha)
do not guarantee any ordering relationship between two loads that depend
on each other on a control dependency:

    read A
    if (val == 1)
        read B

because the conditional may be predicted, and the "read B" may be
speculatively moved up to before reading the value A.  So we require the
user to insert a smp_rmb() between the two accesses to be correct:

    read A;
    if (A == 1)
        smp_rmb()
        read B

Alpha is further special in that it can break that ordering even if the
*address* of B depends on the read of A, because the cacheline that is
read later may be stale unless you have a memory barrier in between the
pointer read and the read of the value behind a pointer:

    read ptr
    read offset(ptr)

whereas all other weakly ordered architectures guarantee that the data
dependency (as opposed to just a control dependency) will order the two
accesses.  As a result, alpha needs a "smp_read_barrier_depends()" in
between those two reads for them to be ordered.

The coontrol dependency that "READ_ONCE_CTRL()" and "atomic_read_ctrl()"
had was a control dependency to a subsequent *write*, however, and
nobody can finalize such a subsequent write without having actually done
the read.  And were you to write such a value to a "stale" cacheline
(the way the unordered reads came to be), that would seem to lose the
write entirely.

So the things that make alpha able to re-order reads even more
aggressively than other weak architectures do not seem to be relevant
for a subsequent write.  Alpha memory ordering may be strange, but
there's no real indication that it is *that* strange.

Also, the alpha architecture reference manual very explicitly talks
about the definition of "Dependence Constraints" in section 5.6.1.7,
where a preceding read dominates a subsequent write.

Such a dependence constraint admittedly does not impose a BEFORE (alpha
architecture term for globally visible ordering), but it does guarantee
that there can be no "causal loop".  I don't see how you could avoid
such a loop if another cpu could see the stored value and then impact
the value of the first read.  Put another way: the read and the write
could not be seen as being out of order wrt other cpus.

So I do not see how these "x_ctrl()" functions can currently be necessary.

I may have to eat my words at some point, but in the absense of clear
proof that alpha actually needs this, or indeed even an explanation of
how alpha could _possibly_ need it, I do not believe these functions are
called for.

And if it turns out that alpha really _does_ need a barrier for this
case, that barrier still should not be "smp_read_barrier_depends()".
We'd have to make up some new speciality barrier just for alpha, along
with the documentation for why it really is necessary.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul E McKenney <paulmck@us.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>