GCC-4.4.4 raises errors when assigning a parameter in an anonymous
union, leading to this kind of failure:

drivers/mtd/nand/marvell_nand.c:1936:
    warning: missing braces around initializer
    warning: (near initialization for '(anonymous)[1].<anonymous>')
    error: unknown field 'data' specified in initializer
    error: unknown field 'addr' specified in initializer

Work around the situation by naming these unions.

Fixes: 8878b126 ("mtd: nand: add ->exec_op() implementation")
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Tested-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

As OneNAND driver is now using devicetree gpmc-onenand and its
platform data is unused and can be removed.
Signed-off-by: NLadislav Michl <ladis@linux-mips.org>
Reviewed-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: NRoger Quadros <rogerq@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Move away from platform data configuration and use pure DT approach.

Use generic probe function to deal with OneNAND node and remove now useless
gpmc_probe_onenand_child function. Import sync mode timing calculation
function from mach-omap2/gpmc-onenand.c
Signed-off-by: NLadislav Michl <ladis@linux-mips.org>
Reviewed-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Tested-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Introduce a new interface to instruct NAND controllers to send specific
NAND operations. The new interface takes the form of a single method
called ->exec_op(). This method is designed to replace ->cmd_ctrl(),
->cmdfunc() and ->read/write_byte/word/buf() hooks.

->exec_op() is passed a set of instructions describing the operation
to execute. Each instruction has a type (ADDR, CMD, DATA, WAITRDY)
and delay. The delay is here to help simple controllers wait enough
time between each instruction, advanced controllers with integrated
timings control can ignore these delays.

Controllers that natively support complex operations (operations
formed of several instructions) can use the NAND op parser
infrastructure. This infrastructure allows controller drivers to
describe the sequence of instructions they support (called
nand_op_pattern) and a hook for each of these supported sequences. The
core then tries to find the best match for a given NAND operation, and
calls the associated hook.

Various other helpers are also added to ease NAND controller drivers
writing.

This new interface should ease support of vendor specific operations
in that NAND manufacturer drivers now have a way to check if the
controller they are connected to supports a specific operation, and
complain or refuse to probe the NAND chip when that's not the case.
Suggested-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

struct nand_buffers is malloc'ed in nand_scan_tail() just for
containing three pointers.  Squash this struct into nand_chip.

Move and rename as follows:

  chip->buffers->ecccalc   ->  chip->ecc.calc_buf
  chip->buffers->ecccode   ->  chip->ecc.code_buf
  chip->buffers->databuf   ->  chip->data_buf
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

The last/only user of NAND_OWN_BUFFERS (cafe_nand.c) has been reworked.
This flag is no longer needed.
Suggested-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

Right now, the chip->data_interface field is populated in
nand_scan_tail(), so after the whole NAND detection has taken place.
This is fine because these timings are not yet used by the core so
early in the probe process, but the situation is about to change with
the introduction of ->exec_op().

Also, by convention, nand_scan_ident() is not supposed to allocate
resources, only nand_scan_tail() can, so this prevent us from
allocating and initializing the data_interface object in
nand_scan_ident().

In order to solve this problem, directly embed a data_interface object
in nand_chip so that we don't have to allocate it, and initialize it to
ONFI SDR mode 0 at the very beginning of nand_scan_ident().
Signed-off-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

The core currently send the READ0 and SEQIN+PAGEPROG commands in
nand_do_read/write_ops(). This is inconsistent with
->read/write_oob[_raw]() hooks behavior which are expected to send
these commands.

There's already a flag (NAND_ECC_CUSTOM_PAGE_ACCESS) to inform the core
that a specific controller wants to send the READ/SEQIN+PAGEPROG
commands on its own, but it's an opt-in flag, and existing drivers are
unlikely to be updated to pass it.

Moreover, some controllers cannot dissociate the READ/PAGEPROG commands
from the associated data transfer and ECC engine activation, and
developers have to hack things in their ->cmdfunc() implementation to
handle such complex cases, or have to accept the perf penalty of sending
twice the same command.
To address this problem we are planning on adding a new interface which
is passed all information about a NAND operation (including the amount
of data to transfer) and replacing all calls to ->cmdfunc() to calls to
this new ->exec_op() hook. But, in order to do that, we need to have all
->cmdfunc() calls placed near their associated ->read/write_buf/byte()
calls.

Modify the core and relevant drivers to make NAND_ECC_CUSTOM_PAGE_ACCESS
the default case, and remove this flag.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
[miquel.raynal@free-electrons.com: tested, fixed and rebased on nand/next]
Signed-off-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Acked-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

This is part of the process of removing direct calls to ->cmdfunc()
outside of the core in order to introduce a better interface to execute
NAND operations.

Here we provide several helpers and make use of them to remove all
direct calls to ->cmdfunc(). This way, we can easily modify those
helpers to make use of the new ->exec_op() interface when available.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
[miquel.raynal@free-electrons.com: rebased and fixed some conflicts]
Signed-off-by: NMiquel Raynal <miquel.raynal@free-electrons.com>
Acked-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

The recent conversion of the task state recording to use task_state_index()
broke the sched_switch tracepoint task state output.

task_state_index() returns surprisingly an index (0-7) which is then
printed with __print_flags() applying bitmasks. Not really working and
resulting in weird states like 'prev_state=t' instead of 'prev_state=I'.

Use TASK_REPORT_MAX instead of TASK_STATE_MAX to report preemption. Build a
bitmask from the return value of task_state_index() and store it in
entry->prev_state, which makes __print_flags() work as expected.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Fixes: efb40f58 ("sched/tracing: Fix trace_sched_switch task-state printing")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1711221304180.1751@nanosSigned-off-by: NIngo Molnar <mingo@kernel.org>

There are no in-tree callers of ht_create_irq(), the driver interface for
HyperTransport interrupts, left.  Remove the unused entry point and all the
supporting code.

See 8b955b0d ("[PATCH] Initial generic hypertransport interrupt
support").
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-pci@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: https://lkml.kernel.org/r/20171122221337.3877.23362.stgit@bhelgaas-glaptop.roam.corp.google.com

Tuntap and similar devices can inject GSO packets. Accept type
VIRTIO_NET_HDR_GSO_UDP, even though not generating UFO natively.

Processes are expected to use feature negotiation such as TUNSETOFFLOAD
to detect supported offload types and refrain from injecting other
packets. This process breaks down with live migration: guest kernels
do not renegotiate flags, so destination hosts need to expose all
features that the source host does.

Partially revert the UFO removal from 182e0b6b~1..d9d30adf.
This patch introduces nearly(*) no new code to simplify verification.
It brings back verbatim tuntap UFO negotiation, VIRTIO_NET_HDR_GSO_UDP
insertion and software UFO segmentation.

It does not reinstate protocol stack support, hardware offload
(NETIF_F_UFO), SKB_GSO_UDP tunneling in SKB_GSO_SOFTWARE or reception
of VIRTIO_NET_HDR_GSO_UDP packets in tuntap.

To support SKB_GSO_UDP reappearing in the stack, also reinstate
logic in act_csum and openvswitch. Achieve equivalence with v4.13 HEAD
by squashing in commit 93991221 ("net: skb_needs_check() removes
CHECKSUM_UNNECESSARY check for tx.") and reverting commit 8d63bee6
("net: avoid skb_warn_bad_offload false positives on UFO").

(*) To avoid having to bring back skb_shinfo(skb)->ip6_frag_id,
ipv6_proxy_select_ident is changed to return a __be32 and this is
assigned directly to the frag_hdr. Also, SKB_GSO_UDP is inserted
at the end of the enum to minimize code churn.

Tested
  Booted a v4.13 guest kernel with QEMU. On a host kernel before this
  patch `ethtool -k eth0` shows UFO disabled. After the patch, it is
  enabled, same as on a v4.13 host kernel.

  A UFO packet sent from the guest appears on the tap device:
    host:
      nc -l -p -u 8000 &
      tcpdump -n -i tap0

    guest:
      dd if=/dev/zero of=payload.txt bs=1 count=2000
      nc -u 192.16.1.1 8000 < payload.txt

  Direct tap to tap transmission of VIRTIO_NET_HDR_GSO_UDP succeeds,
  packets arriving fragmented:

    ./with_tap_pair.sh ./tap_send_ufo tap0 tap1
    (from https://github.com/wdebruij/kerneltools/tree/master/tests)

Changes
  v1 -> v2
    - simplified set_offload change (review comment)
    - documented test procedure

Link: http://lkml.kernel.org/r/<CAF=yD-LuUeDuL9YWPJD9ykOZ0QCjNeznPDr6whqZ9NGMNF12Mw@mail.gmail.com>
Fixes: fb652fdf ("macvlan/macvtap: Remove NETIF_F_UFO advertisement.")
Reported-by: NMichal Kubecek <mkubecek@suse.cz>
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

when the verifier detects that register contains a runtime constant
and it's compared with another constant it will prune exploration
of the branch that is guaranteed not to be taken at runtime.
This is all correct, but malicious program may be constructed
in such a way that it always has a constant comparison and
the other branch is never taken under any conditions.
In this case such path through the program will not be explored
by the verifier. It won't be taken at run-time either, but since
all instructions are JITed the malicious program may cause JITs
to complain about using reserved fields, etc.
To fix the issue we have to track the instructions explored by
the verifier and sanitize instructions that are dead at run time
with NOPs. We cannot reject such dead code, since llvm generates
it for valid C code, since it doesn't do as much data flow
analysis as the verifier does.

Fixes: 17a52670 ("bpf: verifier (add verifier core)")
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

I think this snuck in when I applied the patch for f97decac (didn't
apply cleanly, required some manual applying + git-add).  It is unused
and shouldn't be here.  My bad.

Fixes: f97decac "drm/msm: Support multiple ringbuffers"
Signed-off-by: NRob Clark <robdclark@gmail.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This adds the infrastructure needed to quirk displays
using edid and to mark them a non-desktop.

A non-desktop display is one which shouldn't normally be included
as a part of a desktop environment.

This is meant to cover head mounted devices like HTC Vive.

v2: Change description from non-standard to non-desktop, add docs
Reviewed-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

fixup docs

With the current ARG_PTR_TO_MEM/ARG_PTR_TO_UNINIT_MEM semantics, an helper
argument can be NULL when the next argument type is ARG_CONST_SIZE_OR_ZERO
and the verifier can prove the value of this next argument is 0. However,
most helpers are just interested in handling <!NULL, 0>, so forcing them to
deal with <NULL, 0> makes the implementation of those helpers more
complicated for no apparent benefits, requiring them to explicitly handle
those corner cases with checks that bpf programs could start relying upon,
preventing the possibility of removing them later.

Solve this by making ARG_PTR_TO_MEM/ARG_PTR_TO_UNINIT_MEM never accept NULL
even when ARG_CONST_SIZE_OR_ZERO is set, and introduce a new argument type
ARG_PTR_TO_MEM_OR_NULL to explicitly deal with the NULL case.

Currently, the only helper that needs this is bpf_csum_diff_proto(), so
change arg1 and arg3 to this new type as well.

Also add a new battery of tests that explicitly test the
!ARG_PTR_TO_MEM_OR_NULL combination: all the current ones testing the
various <NULL, 0> variations are focused on bpf_csum_diff, so cover also
other helpers.
Signed-off-by: NGianluca Borello <g.borello@gmail.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The previous fix for addressing the breakage in vmaster slave
initialization, commit a91d6612 ("ALSA: hda - Fix incorrect TLV
callback check introduced during set_fs() removal"), introduced a new
helper to process over each slave kctl.  However, this helper passes
only the original kctl, not the virtual slave kctl.  As a result,
HD-audio driver (which is the only user so far) couldn't initialize
the slave correctly because it's trying to update the value directly
with the original kctl, not with the mapped kctl.

This patch fixes the situation again by passing both the mapped slaved
and original slave kctls to the function.  Luckily there is a single
caller as of now, so changing the call signature is no big matter.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=197959
Fixes: a91d6612 ("ALSA: hda - Fix incorrect TLV callback check introduced during set_fs() removal")
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

With all callbacks converted, and the timer callback prototype
switched over, the TIMER_FUNC_TYPE cast is no longer needed,
so remove it. Conversion was done with the following scripts:

    perl -pi -e 's|\(TIMER_FUNC_TYPE\)||g' \
        $(git grep TIMER_FUNC_TYPE | cut -d: -f1 | sort -u)

    perl -pi -e 's|\(TIMER_DATA_TYPE\)||g' \
        $(git grep TIMER_DATA_TYPE | cut -d: -f1 | sort -u)

The now unused macros are also dropped from include/linux/timer.h.
Signed-off-by: NKees Cook <keescook@chromium.org>

With __init_timer*() now matching __setup_timer*(), remove the redundant
internal interface, clean up the resulting definitions and add more
documentation.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NKees Cook <keescook@chromium.org>

In preparation for removing more macros, pass the function down to the
initialization routines instead of doing it in macros.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NKees Cook <keescook@chromium.org>

With the .data field removed, the ignored data arguments in timer macros
can be removed.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: NKees Cook <keescook@chromium.org>

Since all callbacks have been converted, we can switch the core
prototype to "struct timer_list *" now too.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NKees Cook <keescook@chromium.org>

Now that all timer callbacks are already taking their struct timer_list
pointer as the callback argument, just do this unconditionally and remove
the .data field.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NKees Cook <keescook@chromium.org>

With all callers converted to timer_setup(), the old setup_*timer()
interface can be removed.

Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NKees Cook <keescook@chromium.org>

All users of init_timer() have been updated. Remove the ancient interface.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: NKees Cook <keescook@chromium.org>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: linux-block@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: NKees Cook <keescook@chromium.org>

It doesn't cause a run-time bug, but these bitfields should be unsigned.
When it's signed ->dl_throttled is set to either 0 or -1, instead of
0 and 1 as expected.

The sched.h file is included into tons of places so Sparse generates
a flood of warnings like this:

  ./include/linux/sched.h:477:54: error: dubious one-bit signed bitfield
Reported-by: NMatthew Wilcox <willy@infradead.org>
Reported-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NLuca Abeni <luca.abeni@santannapisa.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Cc: luca abeni <luca.abeni@santannapisa.it>
Link: http://lkml.kernel.org/r/20171013070121.dzcncojuj2f4utij@mwandaSigned-off-by: NIngo Molnar <mingo@kernel.org>

Header implementation of bpf_prog_offload_verifier_prep() which
is used if CONFIG_NET=n should be a static inline.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This reverts commit bd601b6a ("bpf: report offload info to user
space").  The ifindex by itself is not sufficient, we should provide
information on which network namespace this ifindex belongs to.
After considering some options we concluded that it's best to just
remove this API for now, and rework it in -next.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

bpf_prog_get_type() is identical to bpf_prog_get_type_dev(),
with false passed as attach_drv.  Instead of keeping it as
an exported symbol turn it into static inline wrapper.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

With TC shared block changes we can't depend on correct netdev
pointer being available in cls_bpf.  Move the device validation
to the driver.  Core will only make sure that offloaded programs
are always attached in the driver (or in HW by the driver).  We
trust that drivers which implement offload callbacks will perform
necessary checks.

Moving the checks to the driver is generally a useful thing,
in practice the check should be against a switchdev instance,
not a netdev, given that most ASICs will probably allow using
the same program on many ports.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

bpf_target_prog seems long and clunky, rename it to prog_ifindex.
We don't want to call this field just ifindex, because maps
may need a similar field in the future and bpf_attr members for
programs and maps are unnamed.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Fix the TLP scheduling logic so that when scheduling a TLP probe, we
ensure that the estimated time at which an RTO would fire accounts for
the fact that ACKs indicating forward progress should push back RTO
times.

After the following fix:

df92c839 ("tcp: fix xmit timer to only be reset if data ACKed/SACKed")

we had an unintentional behavior change in the following kind of
scenario: suppose the RTT variance has been very low recently. Then
suppose we send out a flight of N packets and our RTT is 100ms:

t=0: send a flight of N packets
t=100ms: receive an ACK for N-1 packets

The response before df92c839 that was:
  -> schedule a TLP for now + RTO_interval

The response after df92c839 is:
  -> schedule a TLP for t=0 + RTO_interval

Since RTO_interval = srtt + RTT_variance, this means that we have
scheduled a TLP timer at a point in the future that only accounts for
RTT_variance. If the RTT_variance term is small, this means that the
timer fires soon.

Before df92c839 this would not happen, because in that code, when
we receive an ACK for a prefix of flight, we did:

    1) Near the top of tcp_ack(), switch from TLP timer to RTO
       at write_queue_head->paket_tx_time + RTO_interval:
            if (icsk->icsk_pending == ICSK_TIME_LOSS_PROBE)
                   tcp_rearm_rto(sk);

    2) In tcp_clean_rtx_queue(), update the RTO to now + RTO_interval:
            if (flag & FLAG_ACKED) {
                   tcp_rearm_rto(sk);

    3) In tcp_ack() after tcp_fastretrans_alert() switch from RTO
       to TLP at now + RTO_interval:
            if (icsk->icsk_pending == ICSK_TIME_RETRANS)
                   tcp_schedule_loss_probe(sk);

In df92c839 we removed that 3-phase dance, and instead directly
set the TLP timer once: we set the TLP timer in cases like this to
write_queue_head->packet_tx_time + RTO_interval. So if the RTT
variance is small, then this means that this is setting the TLP timer
to fire quite soon. This means if the ACK for the tail of the flight
takes longer than an RTT to arrive (often due to delayed ACKs), then
the TLP timer fires too quickly.

Fixes: df92c839 ("tcp: fix xmit timer to only be reset if data ACKed/SACKed")
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a skeleton NTB driver which will be filled out in subsequent patches.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NKurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Seeing the Switchtec NTB hardware shares the same endpoint as the
management endpoint we utilize the class_interface API to register
an NTB driver for every Switchtec device in the system that has the
NTB class code.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NKurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@dell.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Adds a comment and a check to ntb_mw_get_align() so that it always fails
if the function is called before the link is up.

Also adds a comment to ntb_mw_count() to note that it may return 0 if
it is called before the link is up.

This is to prevent accidental mis-use in clients that are testing
on hardware that this doesn't matter for.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

In order for the Switchtec NTB code to handle link change events we
create a notifier callback in the switchtec code which gets called
whenever an appropriate event interrupt occurs.

In order to preserve userspace's ability to follow these events,
we compare the event count with a stored copy from last time we
checked.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NKurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

There are two additional regions: ctrl and dbmsg. The first is
for generic NTB control and memory windows. The second is for doorbells
and message registers. This patch also adds a number of related
constants for using these registers.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NKurt Schwemmer <kurt.schwemmer@microsemi.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

We export the class pointer symbol and add an extern define in the
Switchtec header file.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NKurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Create the switchtec.h header in include/linux with hardware defines
and the switchtec_dev structure. Both moved directly from switchtec.c.
This is a prep patch for creating an NTB driver for Switchtec.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NStephen Bates <sbates@raithlin.com>
Reviewed-by: NKurt Schwemmer <kurt.schwemmer@microsemi.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>