Based on Alex's review notes on [1], we don't need to write
to the buf_info elements as often, and can tighten up how they
are used.  Also, use prefetchw() to warm up the page struct
for a later get_page().

[1] https://lore.kernel.org/netdev/CAKgT0UfyjoAN7LTnq0NMZfXRv4v7iTCPyAb9pVr3qWMhop_BVw@mail.gmail.com/Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Initialize err to 0 instead of ENOMEM, and specifically set
err to ENOMEM in the devm_kcalloc() failure cases.

Also, add an error message to the end of reconfig.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Print the version of the DSC firmware seen when we do a fresh
ident check.  Because the FW can be updated by the external
orchestration system, this helps us track that FW has been
updated on the DSC.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

The top 4 bits of the fw_status in dev_info_regs is reserved
for the status generation.  This generation number is an
arbitrary value defined when firmware starts up.  If the FW
is killed/crashed/stopped and then restarted, it will create
a different generation number.  With this mechanism, the host
driver can detect that the FW has crashed and restarted, and
the driver can then take steps to re-initialize its connection.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

When running in a small kdump kernel, we can play nice and
minimize our resource use to help make sure that kdump is
successful in its mission.
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Arnd Bergmann says:

====================
ndo_ioctl rework

This series is a follow-up to the series for removing
compat_alloc_user_space() and copy_in_user() that has now
been merged.

I wanted to be sure I address all the ways that 'struct ifreq' is used
in device drivers through .ndo_do_ioctl, originally to prove that
my approach of changing the struct definition was correct, but then
I discarded that approach and went on anyway.

Roughly, the contents here are:

 - split out all the users of SIOCDEVPRIVATE ioctls into a
   separate ndo_siocdevprivate callback, to better see what
   gets used where

 - fix compat handling for those drivers that pass data
   directly inside of 'ifreq' rather than using an indirect
   ifr_data pointer

 - remove unreachable code in ndo_ioctl handlers that relies
   on command codes we never pass into that, in particular
   for wireless drivers

 - split out the ethernet specific ioctls into yet another
   ndo_eth_ioctl callback, as these are by far the most
   common use of ndo_do_ioctl today. I considered splitting
   them further into MII and timestamp controls, but
   went with the simpler change for now.

 - split out bonding and wandev ioctls into separate helpers

 - rework the bridge handling with a separate callback

At this point, only a few oddball things remain in ndo_do_ioctl:
appletalk and ieee802154 pass down SIOCSIFADDR/SIOCGIFADDR and
some wireless drivers have completely dead code.

I have thoroughly compile tested this on randconfig builds,
but not done any notable runtime testing, so please review.
All of it is also available as part of a larger branch at

https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git \
	compat-alloc-user-space-12

Changes since v2:
- rebase to net-next
- fix qeth regression
- Cc driver maintainers for each patch and in cover letter

Changes since v1:

- rebase to linux-5.14-rc2
- add conversion for ndo_siowandev, bridge and bonding drivers
- leave broken wifi drivers untouched for now

Link: https://lore.kernel.org/netdev/20201106221743.3271965-14-arnd@kernel.org/
====================

All other user triggered operations are gone from ndo_ioctl, so move
the SIOCBOND family into a custom operation as well.

The .ndo_ioctl() helper is no longer called by the dev_ioctl.c code now,
but there are still a few definitions in obsolete wireless drivers as well
as the appletalk and ieee802154 layers to call SIOCSIFADDR/SIOCGIFADDR
helpers from inside the kernel.

Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Working towards obsoleting the .ndo_do_ioctl operation entirely,
stop passing the SIOCBRADDIF/SIOCBRDELIF device ioctl commands
into this callback.

My first attempt was to add another ndo_siocbr() callback, but
as there is only a single driver that takes these commands and
there is already a hook mechanism to call directly into this
driver, extend this hook instead, and use it for both the
deviceless and the device specific ioctl commands.

Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <nikolay@nvidia.com>
Cc: bridge@lists.linux-foundation.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some drivers that use SIOCDEVPRIVATE ioctl commands modify
the ifreq structure and expect it to be passed back to user
space, which has never really happened for compat mode
because the calling these drivers through ndo_do_ioctl
requires overwriting the ifr_data pointer.

Now that all drivers are converted to ndo_siocdevprivate,
change it to handle this correctly in both compat and
native mode.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

In order to further reduce the scope of ndo_do_ioctl(), move
out the SIOCWANDEV handling into a new network device operation
function.

Adjust the prototype to only pass the if_settings sub-structure
in place of the ifreq, and remove the redundant 'cmd' argument
in the process.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Cc: Kevin Curtis <kevin.curtis@farsite.co.uk>
Cc: Zhao Qiang <qiang.zhao@nxp.com>
Cc: Martin Schiller <ms@dev.tdt.de>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: linux-x25@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Most users of ndo_do_ioctl are ethernet drivers that implement
the MII commands SIOCGMIIPHY/SIOCGMIIREG/SIOCSMIIREG, or hardware
timestamping with SIOCSHWTSTAMP/SIOCGHWTSTAMP.

Separate these from the few drivers that use ndo_do_ioctl to
implement SIOCBOND, SIOCBR and SIOCWANDEV commands.

This is a purely cosmetic change intended to help readers find
their way through the implementation.

Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Vivien Didelot <vivien.didelot@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Vladimir Oltean <olteanv@gmail.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: linux-rdma@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The compat handlers for SIOCDEVPRIVATE are incorrect for any driver that
passes data as part of struct ifreq rather than as an ifr_data pointer, or
that passes data back this way, since the compat_ifr_data_ioctl() helper
overwrites the ifr_data pointer and does not copy anything back out.

Since all drivers using devprivate commands are now converted to the
new .ndo_siocdevprivate callback, fix this by adding the missing piece
and passing the pointer separately the whole way.

This further unifies the native and compat logic for socket ioctls,
as the new code now passes the correct pointer as well as the correct
data for both native and compat ioctls.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ndo_do_ioctl callback is never called with the COSAIO* commands,
so this is never used. Call the hdlc_ioctl function directly instead.

Any user space code that relied on this function working as intended
has never worked in a mainline kernel since before linux-1.0.

Cc: "Jan \"Yenya\" Kasprzak" <kas@fi.muni.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The wan drivers each support some custom SIOCDEVPRIVATE
ioctls, plus the common SIOCWANDEV command.

Split these so the ioctl callback only deals with SIOCWANDEV
and the rest is handled by ndo_siocdevprivate.

It might make sense to also split out SIOCWANDEV into a
separate callback in order to eventually remove ndo_do_ioctl
entirely.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Kevin Curtis <kevin.curtis@farsite.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

ppp has a custom statistics interface using SIOCDEVPRIVATE
ioctl commands that works correctly in compat mode.

Convert it to use ndo_siocdevprivate as a cleanup.

Cc: Paul Mackerras <paulus@samba.org>
Cc: linux-ppp@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The private sb1000 ioctl commands all work correctly in
compat mode. Change the to ndo_siocdevprivate as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The rr_ioctl uses private ioctl commands that correctly pass
all data through ifr_data, which works fine in compat mode.

Change it to use ndo_siocdevprivate as a cleanup.

Cc: Jes Sorensen <jes@trained-monkey.org>
Cc: linux-hippi@sunsite.dk
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The various ipv4 and ipv6 tunnel drivers each implement a set
of 12 SIOCDEVPRIVATE commands for managing tunnels. These
all work correctly in compat mode.

Move them over to the new .ndo_siocdevprivate operation.

Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Ahern <dsahern@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The airo driver overloads SIOCDEVPRIVATE ioctls with another
set based on SIOCIWFIRSTPRIV. Only the first ones actually
work (also in compat mode) as the others do not get passed
down any more.

Change it over to ndo_siocdevprivate for clarification.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: linux-wireless@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

hamradio uses a set of private ioctls that do seem to work
correctly in compat mode, as they only rely on the ifr_data
pointer.

Move them over to the ndo_siocdevprivate callback as a cleanup.

Cc: Thomas Sailer <t.sailer@alumni.ethz.ch>
Cc: Joerg Reuter <jreuter@yaina.de>
Cc: Jean-Paul Roubelat <jpr@f6fbb.org>
Cc: linux-hams@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

cxgb3 has a private multiplexor that works correctly in compat
mode, split out the siocdevprivate callback from do_ioctl for
simplification.

Cc: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

qeth has both standard MII ioctls and custom SIOCDEVPRIVATE ones,
all of which work correctly with compat user space.

Move the private ones over to the new ndo_siocdevprivate callback.

Cc: Julian Wiedmann <jwi@linux.ibm.com>
Cc: Karsten Graul <kgraul@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

slip and plip both use a couple of SIOCDEVPRIVATE ioctl
commands that overload the ifreq layout in a way that is
incompatible with compat mode.

Convert to use ndo_siocdevprivate to allow passing the
data this way, but return an error in compat mode anyway
because the private structure is still incompatible.

This could be fixed as well to make compat work properly.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The pegasus and rtl8150 drivers use SIOCDEVPRIVATE ioctls
to access their MII registers, in place of the normal
commands. This is broken for all compat ioctls today.

Change to ndo_siocdevprivate to fix it.

Cc: Petko Manolov <petkan@nucleusys.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The skfddi driver has a private ioctl and passes the data correctly
through ifr_data, but the use of a pointer in s_skfp_ioctl is
broken in compat mode.

Change the driver to use ndo_siocdevprivate and disallow calling
it in compat mode until a conversion handler is added.

Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The private ioctls in eql pass the arguments correctly through ifr_data,
but the slaving_request_t and slave_config_t structures are incompatible
with compat mode and need special conversion code in the driver.

Convert to siocdevprivate for now, and return an error when called
in compat mode.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tehuti only implements private ioctl commands, and implements
them by overriding the ifreq layout, which is broken in
compat mode.

Move it to the ndo_siocdevprivate callback in order to fix this.

Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

hamachi has one command that overloads the ifreq argument
and requires a conversion to ndo_siocdevprivate in order to
make compat mode work, so split it from ndo_ioctl.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

appletalk has three SIOCDEVPRIVATE ioctl commands that are
broken in compat mode because the passed structure contains
a pointer.

Change it over to ndo_siocdevprivate for consistency and
make it return an error when called in compat mode. This
could be fixed if there are still users.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The bonding driver supports two command codes for each operation: one
in the SIOCDEVPRIVATE range and another one with the same definition
but a unique command code.

Only the second set currently works in compat mode, as the ifr_data
expansion overwrites part of the ifr_slave field.

Move the private ones into ndo_siocdevprivate and change the
implementation to call the other function.  This makes both version
work correctly.

Cc: Jay Vosburgh <j.vosburgh@gmail.com>
Cc: Veaceslav Falico <vfalico@gmail.com>
Cc: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

The tulip driver has a debugging method over ioctl built-in, but it
does not actually check the command type, which may end up leading
to random behavior when trying to run other ioctls on it.

Change the driver to use ndo_siocdevprivate and limit the execution
further to the first private command code. If anyone still has tools
to run these debugging commands, they might have to be patched for
it if they pass different ioctl command.

The function has existed in this form since the driver was merged in
Linux-1.1.86.

Cc: linux-parisc@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

phonet has a single private ioctl that is broken in compat
mode on big-endian machines today because the data returned
from it is never copied back to user space.

Move it over to the ndo_siocdevprivate callback, which also
fixes the compat issue.

Cc: Remi Denis-Courmont <courmisch@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Rémi Denis-Courmont <courmisch@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The bridge driver has an old set of ioctls using the SIOCDEVPRIVATE
namespace that have never worked in compat mode and are explicitly
forbidden already.

Move them over to ndo_siocdevprivate and fix compat mode for these,
because we can.

Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: Nikolay Aleksandrov <nikolay@nvidia.com>
Cc: bridge@lists.linux-foundation.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

hostap has a combination of iwpriv ioctls that do not work at
all, and two SIOCDEVPRIVATE commands that work natively but
lack a compat conversion handler.

For the moment, move them over to the new ndo_siocdevprivate
interface and return an error for compat mode.

Cc: Jouni Malinen <j@w1.fi>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

wlan-ng has two private ioctls that correctly work in compat
mode. Move these over to the new ndo_siocdevprivate mechanism.

The p80211netdev_ethtool() function is commented out and
has no use here, so this can be removed
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtl8188eu has an "android private" ioctl command multiplexer
that is not currently safe for use in compat mode because
of its triple-indirect pointer.

rtl8723bs uses a different interface on the SIOCDEVPRIVATE
command, based on the iwpriv data structure

Both also have normal unreachable iwpriv commands, and all
of the above should probably just get removed. For the
moment, just switch over to the new interface.

Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

SIOCDEVPRIVATE ioctl commands are mainly used in really old
drivers, and they have a number of problems:

- They hide behind the normal .ndo_do_ioctl function that
  is also used for other things in modern drivers, so it's
  hard to spot a driver that actually uses one of these

- Since drivers use a number different calling conventions,
  it is impossible to support compat mode for them in
  a generic way.

- With all drivers using the same 16 commands codes, there
  is no way to introspect the data being passed through
  things like strace.

Add a new net_device_ops callback pointer, to address the
first two of these. Separating them from .ndo_do_ioctl
makes it easy to grep for drivers with a .ndo_siocdevprivate
callback, and the unwieldy name hopefully makes it easier
to spot in code review.

By passing the ifreq structure and the ifr_data pointer
separately, it is no longer necessary to overload these,
and the driver can use either one for a given command.

Cc: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Neal Cardwell says:

====================
more accurate DSACK processing for RACK-TLP

This patch series includes two minor improvements to tighten up the accuracy of
the processing of incoming DSACK information, so that RACK-TLP behavior is
faster and more precise: first, to ensure we detect packet loss in some extra
corner cases; and second, to avoid growing the RACK reordering window (and
delaying fast recovery) in cases where it seems clear we don't need to.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Previously, a DSACK could expand the RACK reordering window when no
reordering has been seen, and/or when the DSACK was due to an
unnecessary TLP retransmit (rather than a spurious fast recovery due
to reordering). This could result in unnecessarily growing the RACK
reordering window and thus unnecessarily delaying RACK-based fast
recovery episodes.

To avoid these issues, this commit tightens the conditions under which
a DSACK triggers the RACK reordering window to grow, so that a
connection only expands its RACK reordering window if:

(a) reordering has been seen in the connection
(b) a DSACKed range does not match the most recent TLP retransmit
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Priyaranjan Jha <priyarjha@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Previously TLP is considered spurious if the sender receives any
DSACK during a TLP episode. This patch further checks the DSACK
sequences match the TLP's to improve accuracy.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Priyaranjan Jha <priyarjha@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>