Using ssthresh to revert cwnd is less reliable when ssthresh is
bounded to 2 packets. This patch uses an existing variable in TCP
"prior_cwnd" that snapshots the cwnd right before entering fast
recovery and RTO recovery in Reno.  This fixes the issue discussed
in netdev thread: "A buggy behavior for Linux TCP Reno and HTCP"
https://www.spinics.net/lists/netdev/msg444955.htmlSuggested-by: NNeal Cardwell <ncardwell@google.com>
Reported-by: NWei Sun <unlcsewsun@gmail.com>
Signed-off-by: NYuchung Cheng <ncardwell@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for reading module EEPROMs through phylink.
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The link between the ethernet MAC and its PHY has become more complex
as the interface evolves.  This is especially true with serdes links,
where the part of the PHY is effectively integrated into the MAC.

Serdes links can be connected to a variety of devices, including SFF
modules soldered down onto the board with the MAC, a SFP cage with
a hotpluggable SFP module which may contain a PHY or directly modulate
the serdes signals onto optical media with or without a PHY, or even
a classical PHY connection.

Moreover, the negotiation information on serdes links comes in two
varieties - SGMII mode, where the PHY provides its speed/duplex/flow
control information to the MAC, and 1000base-X mode where both ends
exchange their abilities and each resolve the link capabilities.

This means we need a more flexible means to support these arrangements,
particularly with the hotpluggable nature of SFP, where the PHY can
be attached or detached after the network device has been brought up.

Ethtool information can come from multiple sources:
- we may have a PHY operating in either SGMII or 1000base-X mode, in
  which case we take ethtool/mii data directly from the PHY.
- we may have a optical SFP module without a PHY, with the MAC
  operating in 1000base-X mode - the ethtool/mii data needs to come
  from the MAC.
- we may have a copper SFP module with a PHY whic can't be accessed,
  which means we need to take ethtool/mii data from the MAC.

Phylink aims to solve this by providing an intermediary between the
MAC and PHY, providing a safe way for PHYs to be hotplugged, and
allowing a SFP driver to reconfigure the serdes connection.

Phylink also takes over support of fixed link connections, where the
speed/duplex/flow control are fixed, but link status may be controlled
by a GPIO signal.  By avoiding the fixed-phy implementation, phylink
can provide a faster response to link events: fixed-phy has to wait for
phylib to operate its state machine, which can take several seconds.
In comparison, phylink takes milliseconds.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

- remove sync status
- rework supported and advertisment handling
- add 1000base-x speed for fixed links
- use functionality exported from phy-core, reworking
  __phylink_ethtool_ksettings_set for it
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sometimes, we need to do additional work between the PHY coming up and
marking the carrier present - for example, we may need to wait for the
PHY to MAC link to finish negotiation.  This changes phylib to provide
a notification function pointer which avoids the built-in
netif_carrier_on() and netif_carrier_off() functions.

Standard ->adjust_link functionality is provided by hooking a helper
into the new ->phy_link_change method.
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

phy_lookup_setting() provides useful functionality in ethtool code
outside phylib.  Move it to phy-core and allow it to be re-used (eg,
in phylink) rather than duplicated elsewhere.  Note that this supports
the larger linkmode space.

As we move the phy settings table, we also need to move the guts of
phy_supported_speeds() as well.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Other code would like to make use of this, so make the speed and duplex
string generation visible, and place it in a separate file.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bound the number of pages that a user may pin.

Follow the lead of perf tools to maintain a per-user bound on memory
locked pages commit 789f90fc ("perf_counter: per user mlock gift")
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the simple case, each sendmsg() call generates data and eventually
a zerocopy ready notification N, where N indicates the Nth successful
invocation of sendmsg() with the MSG_ZEROCOPY flag on this socket.

TCP and corked sockets can cause send() calls to append new data to an
existing sk_buff and, thus, ubuf_info. In that case the notification
must hold a range. odify ubuf_info to store a inclusive range [N..N+m]
and add skb_zerocopy_realloc() to optionally extend an existing range.

Also coalesce notifications in this common case: if a notification
[1, 1] is about to be queued while [0, 0] is the queue tail, just modify
the head of the queue to read [0, 1].

Coalescing is limited to a few TSO frames worth of data to bound
notification latency.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Prepare the datapath for refcounted ubuf_info. Clone ubuf_info with
skb_zerocopy_clone() wherever needed due to skb split, merge, resize
or clone.

Split skb_orphan_frags into two variants. The split, merge, .. paths
support reference counted zerocopy buffers, so do not do a deep copy.
Add skb_orphan_frags_rx for paths that may loop packets to receive
sockets. That is not allowed, as it may cause unbounded latency.
Deep copy all zerocopy copy buffers, ref-counted or not, in this path.

The exact locations to modify were chosen by exhaustively searching
through all code that might modify skb_frag references and/or the
the SKBTX_DEV_ZEROCOPY tx_flags bit.

The changes err on the safe side, in two ways.

(1) legacy ubuf_info paths virtio and tap are not modified. They keep
    a 1:1 ubuf_info to sk_buff relationship. Calls to skb_orphan_frags
    still call skb_copy_ubufs and thus copy frags in this case.

(2) not all copies deep in the stack are addressed yet. skb_shift,
    skb_split and skb_try_coalesce can be refined to avoid copying.
    These are not in the hot path and this patch is hairy enough as
    is, so that is left for future refinement.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The kernel supports zerocopy sendmsg in virtio and tap. Expand the
infrastructure to support other socket types. Introduce a completion
notification channel over the socket error queue. Notifications are
returned with ee_origin SO_EE_ORIGIN_ZEROCOPY. ee_errno is 0 to avoid
blocking the send/recv path on receiving notifications.

Add reference counting, to support the skb split, merge, resize and
clone operations possible with SOCK_STREAM and other socket types.

The patch does not yet modify any datapaths.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Refine skb_copy_ubufs to support compound pages. With upcoming TCP
zerocopy sendmsg, such fragments may appear.

The existing code replaces each page one for one. Splitting each
compound page into an independent number of regular pages can result
in exceeding limit MAX_SKB_FRAGS if data is not exactly page aligned.

Instead, fill all destination pages but the last to PAGE_SIZE.
Split the existing alloc + copy loop into separate stages:
1. compute bytelength and minimum number of pages to store this.
2. allocate
3. copy, filling each page except the last to PAGE_SIZE bytes
4. update skb frag array
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_auth_chunk_t, and
replace with struct sctp_auth_chunk in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_authhdr_t, and
replace with struct sctp_authhdr in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_addip_chunk_t, and
replace with struct sctp_addip_chunk in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_addiphdr_t, and
replace with struct sctp_addiphdr in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_addip_param_t, and
replace with struct sctp_addip_param in the places where it's
using this typedef.

It is to use sizeof(variable) instead of sizeof(type), and
also fix some indent problems.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove this typedef including the struct, there is even no places
using it.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_cwrhdr_t, and
replace with struct sctp_cwrhdr in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_ecne_chunk_t, and
replace with struct sctp_ecne_chunk in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_ecnehdr_t, and
replace with struct sctp_ecnehdr in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_error_t, and replace
with enum sctp_error in the places where it's using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_operr_chunk_t, and
replace with struct sctp_operr_chunk in the places where it's
using this typedef.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_errhdr_t, and replace
with struct sctp_errhdr in the places where it's using this
typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to fix the name of struct sctp_shutdown_chunk_t
, replace with struct sctp_initack_chunk in the places where
it's using it.

It is also to fix some indent problem.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to remove the typedef sctp_shutdownhdr_t, and
replace with struct sctp_shutdownhdr in the places where it's
using this typedef.

It is also to use sizeof(variable) instead of sizeof(type).
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

They are introduced by commit f70ea018
("net: Add functions to get skb->hash based on flow structures")
but never gets used in tree.
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Skb frags may contain compound pages. Various operations map frags
temporarily using kmap_atomic, but this function works on single
pages, not whole compound pages. The distinction is only relevant
for high mem pages that require temporary mappings.

Introduce a looping mechanism that for compound highmem pages maps
one page at a time, does not change behavior on other pages.
Use the loop in the kmap_atomic callers in net/core/skbuff.c.

Verified by triggering skb_copy_bits with

    tcpdump -n -c 100 -i ${DEV} -w /dev/null &
    netperf -t TCP_STREAM -H ${HOST}

  and by triggering __skb_checksum with

    ethtool -K ${DEV} tx off

  repeated the tests with looping on a non-highmem platform
  (x86_64) by making skb_frag_must_loop always return true.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add skb_send_sock to send an skbuff on a socket within the kernel.
Arguments include an offset so that an skbuf might be sent in mulitple
calls (e.g. send buffer limit is hit).
Signed-off-by: NTom Herbert <tom@quantonium.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add new proto_ops sendmsg_locked and sendpage_locked that can be
called when the socket lock is already held. Correspondingly, add
kernel_sendmsg_locked and kernel_sendpage_locked as front end
functions.

These functions will be used in zero proxy so that we can take
the socket lock in a ULP sendmsg/sendpage and then directly call the
backend transport proto_ops functions.
Signed-off-by: NTom Herbert <tom@quantonium.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit 67a51780 ("ipv6: udp: leverage scratch area
helpers") udp6_recvmsg() read the skb len from the scratch area,
to avoid a cache miss.
But the UDP6 rx path support RFC 2675 UDPv6 jumbograms, and their
length exceeds the 16 bits available in the scratch area. As a side
effect the length returned by recvmsg() is:
<ingress datagram len> % (1<<16)

This commit addresses the issue allocating one more bit in the
IP6CB flags field and setting it for incoming jumbograms.
Such field is still in the first cacheline, so at recvmsg()
time we can check it and fallback to access skb->len if
required, without a measurable overhead.

Fixes: 67a51780 ("ipv6: udp: leverage scratch area helpers")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for having the bcmgenet driver migrate over the
mdio-bcm-unimac driver, add a platform data structure which allows
passing integrating specific details like bus name, wait function to
complete MDIO operations and PHY mask.

We also define what the platform device name contract is by defining
UNIMAC_MDIO_DRV_NAME and moving it to the platform_data header.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like prequeue, I am not sure this is overly useful nowadays.

If we receive a train of packets, GRO will aggregate them if the
headers are the same (HP predates GRO by several years) so we don't
get a per-packet benefit, only a per-aggregated-packet one.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

prequeue is a tcp receive optimization that moves part of rx processing
from bh to process context.

This only works if the socket being processed belongs to a process that
is blocked in recv on that socket.

In practice, this doesn't happen anymore that often because nowadays
servers tend to use an event driven (epoll) model.

Even normal client applications (web browsers) commonly use many tcp
connections in parallel.

This has measureable impact only in netperf (which uses plain recv and
thus allows prequeue use) from host to locally running vm (~4%), however,
there were no changes when using netperf between two physical hosts with
ixgbe interfaces.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Forward Error Correction (FEC) modes i.e Base-R
and Reed-Solomon modes are introduced in 25G/40G/100G standards
for providing good BER at high speeds. Various networking devices
which support 25G/40G/100G provides ability to manage supported FEC
modes and the lack of FEC encoding control and reporting today is a
source for interoperability issues for many vendors.
FEC capability as well as specific FEC mode i.e. Base-R
or RS modes can be requested or advertised through bits D44:47 of
base link codeword.

This patch set intends to provide option under ethtool to manage
and report FEC encoding settings for networking devices as per
IEEE 802.3 bj, bm and by specs.

set-fec/show-fec option(s) are designed to provide control and
report the FEC encoding on the link.

SET FEC option:
root@tor: ethtool --set-fec  swp1 encoding [off | RS | BaseR | auto]

Encoding: Types of encoding
Off    :  Turning off any encoding
RS     :  enforcing RS-FEC encoding on supported speeds
BaseR  :  enforcing Base R encoding on supported speeds
Auto   :  IEEE defaults for the speed/medium combination

Here are a few examples of what we would expect if encoding=auto:
- if autoneg is on, we are  expecting FEC to be negotiated as on or off
  as long as protocol supports it
- if the hardware is capable of detecting the FEC encoding on it's
      receiver it will reconfigure its encoder to match
- in absence of the above, the configuration would be set to IEEE
  defaults.

>From our  understanding , this is essentially what most hardware/driver
combinations are doing today in the absence of a way for users to
control the behavior.

SHOW FEC option:
root@tor: ethtool --show-fec  swp1
FEC parameters for swp1:
Active FEC encodings: RS
Configured FEC encodings:  RS | BaseR

ETHTOOL DEVNAME output modification:

ethtool devname output:
root@tor:~# ethtool swp1
Settings for swp1:
root@hpe-7712-03:~# ethtool swp18
Settings for swp18:
    Supported ports: [ FIBRE ]
    Supported link modes:   40000baseCR4/Full
                            40000baseSR4/Full
                            40000baseLR4/Full
                            100000baseSR4/Full
                            100000baseCR4/Full
                            100000baseLR4_ER4/Full
    Supported pause frame use: No
    Supports auto-negotiation: Yes
    Supported FEC modes: [RS | BaseR | None | Not reported]
    Advertised link modes:  Not reported
    Advertised pause frame use: No
    Advertised auto-negotiation: No
    Advertised FEC modes: [RS | BaseR | None | Not reported]
<<<< One or more FEC modes
    Speed: 100000Mb/s
    Duplex: Full
    Port: FIBRE
    PHYAD: 106
    Transceiver: internal
    Auto-negotiation: off
    Link detected: yes

This patch includes following changes
a) New ETHTOOL_SFECPARAM/SFECPARAM API, handled by
  the new get_fecparam/set_fecparam callbacks, provides support
  for configuration of forward error correction modes.
b) Link mode bits for FEC modes i.e. None (No FEC mode), RS, BaseR/FC
  are defined so that users can configure these fec modes for supported
  and advertising fields as part of link autonegotiation.
Signed-off-by: NVidya Sagar Ravipati <vidya.chowdary@gmail.com>
Signed-off-by: NDustin Byford <dustin@cumulusnetworks.com>
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to mark relevant fields while setting the MTPPS register
add field select. Otherwise it can cause a misconfiguration in
firmware.

Fixes: ee7f1220 ('net/mlx5e: Implement 1PPS support')
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Fix miscalculation in reserved_at_1a0 field.

Fixes: ee7f1220 ('net/mlx5e: Implement 1PPS support')
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

That commit was part of the changes moving x86 to the generic CPU hotplug
interrupt migration code. The force flag was required on x86 before the
hierarchical irqdomain rework, but invoking set_affinity() with force=true
stayed and had no side effects.

At some point in the past, the force flag got repurposed to support the
exynos timer interrupt affinity setting to a not yet online CPU, so the
interrupt controller callback does not verify the supplied affinity mask
against cpu_online_mask.

Setting the flag in the CPU hotplug code causes the cpu online masking to
be blocked on these irq controllers and results in potentially affining an
interrupt to the CPU which is unplugged, i.e. instead of moving it away,
it's just reassigned to it.

As the force flags is not longer needed on x86, it's safe to revert that
patch so the ARM irqchips which use the force flag work again.

Add comments to that effect, so this won't happen again.

Note: The online mask handling should be done in the generic code and the
force flag and the masking in the irq chips removed all together, but
that's not a change possible for 4.13. 

Fixes: 77f85e66 ("genirq/cpuhotplug: Set force affinity flag on hotplug migration")
Reported-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: LAK <linux-arm-kernel@lists.infradead.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1707271217590.3109@nanosSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Since the PMU register interface is banked per CPU, CPU PMU interrrupts
cannot be handled by a CPU other than the one with the PMU asserting the
interrupt. This means that migrating PMU SPIs, as we do during a CPU
hotplug operation doesn't make any sense and can lead to the IRQ being
disabled entirely if we route a spurious IRQ to the new affinity target.

This has been observed in practice on AMD Seattle, where CPUs on the
non-boot cluster appear to take a spurious PMU IRQ when coming online,
which is routed to CPU0 where it cannot be handled.

This patch passes IRQF_PERCPU for PMU SPIs and forcefully sets their
affinity prior to requesting them, ensuring that they cannot
be migrated during hotplug events. This interacts badly with the DB8500
erratum workaround that ping-pongs the interrupt affinity from the handler,
so we avoid passing IRQF_PERCPU in that case by allowing the IRQ flags
to be overridden in the platdata.

Fixes: 3cf7ee98 ("drivers/perf: arm_pmu: move irq request/free into probe")
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Maximum coalesce per Rx/Tx queue is extended from
255 to 511.
Signed-off-by: NRahul Verma <rahul.verma@cavium.com>
Signed-off-by: NYuval Mintz <yuval.mintz@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>