Seth David Schoen says:

====================
Treat IPv4 lowest address as ordinary unicast address

Treat the lowest address in a subnet (the address within the subnet
which contains all 0 bits) as an ordinary unicast address instead
of as a potential second broadcast address.  For example, in subnet
192.168.17.24/29, which contains 8 addresses, make address 192.168.17.24
usable as a normal unicast address (while continuing to support
192.168.17.31 as a broadcast address).

Since EVERY network number or subnet formerly had its host number 0
reserved, this patchset adds 1 more usable host address to every network
and subnet (i.e., 2^(32-n)-1 instead of 2^(32-n)-2 addresses available
for assignment on each IPv4 /n subnet).  For small subnets, this is a
significant gain; instead of 6 usable host addresses, a /29 would now
contain 7, a 16% increase.

The reserving of host number 0 for broadcast came about in RFC 1122 from
1989 (page 31, "IP addresses are not permitted to have the value 0 or -1
for any of the <Host-number>, <Network-number>, or <Subnet-number>
fields (except in the special cases listed above)" and page 66, "There
is a class of hosts [4.2BSD Unix and its derivatives, but not 4.3BSD]
that use non-standard broadcast address forms, substituting 0 for -1.
All hosts SHOULD recognize and accept any of these non-standard
broadcast addresses as the destination address of an incoming
datagram.").  This has been repeated in subsequent RFCs, always with
backwards-compatibility rationales.  Network troubles (broadcast storms)
ensued when some early hosts on a LAN treated the lowest address as
unicast and others treated it as broadcast.  Multiple 1989 changes to IP
successfully prevented these.  The key was adding the layering violation
rule requiring hosts to ignore all IP datagrams with unicast destination
addresses that were received in low-level (Ethernet) broadcasts.  That
change is still in effect, and this patchset does not alter it.  All
operating systems since 4.3BSD, including all the current BSD OSes, now
use the standard IP broadcast address.  4.2BSD has been obsolete for
more than 30 years, and all modern hosts ignore hardware broadcasts
containing unicast IP addresses, so there is no modern likelihood of
broadcast storms even when hosts disagree on the unicast vs. broadcast
status of a given address.

Tests with this patchset show that other Linux hosts on the local segment
simply ignore a host numbered with the lowest address, both for incoming
and outgoing packet purposes.  They don't interoperate with it, but they
also don't cause broadcast storms or any other malfunction.  If patched,
they have no trouble interoperating with a host at the lowest address.

Unmodified "distant" hosts that are not on the same segment successfully
interoperate, as long as the gateway on the local segment, and the local
host itself using the lowest address, have this patch.  (Distant hosts
have no way of knowing whether a given address is the lowest address
in a faraway network segment, so they treat it no differently than any
other unicast address.)  This means that each local site can change this
behavior locally, resulting immediately in global interoperability with
the newly usable lowest local address.

Modern software and documentation continues to use the definition of the
directed, or "net-directed", broadcast address as "a host ID of all one
bits".  The Internet no longer gets any benefit from having two different
broadcast addresses usable on every Ethernet segment.  I have not been
able to find any documentation that suggests that users or software should
ever intentionally use the all-zero form, or that justifies it other than
as a historic Berkeleyism.  RFCs 1112, 1812, and 3021 state that hosts and
routers need to maintain compatibility with the old form -- but they give
no rationale other than the past existence of the 4.2BSD behavior.

We're happy to provide more historical details or information about
behavior of other systems in this regard by e-mail or as future patches
to kernel documentation files.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Expect the lowest IPv4 address in a subnet to be assignable
and addressable as a unicast (non-broadcast) address on a
local network segment.
Signed-off-by: Seth David Schoen <schoen@loyalty.org>
Suggested-by: John Gilmore <gnu@toad.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Treat only the highest, not the lowest, IPv4 address within a local
subnet as a broadcast address.
Signed-off-by: Seth David Schoen <schoen@loyalty.org>
Suggested-by: John Gilmore <gnu@toad.com>
Acked-by: Dave Taht <dave.taht@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

With the use of the qca8k dsa driver, some problem arised related to
port status detection. With a load on a specific port (for example a
simple speed test), the driver starts to behave in a strange way and
garbage data is produced. To address this, enlarge the sleep delay and
address a bug for the reg offset 31 that require additional delay for
this specific reg.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mdio drivers should not use REGCHACHE. Also disable locking since it's
handled by the mdio users and regmap is always accessed atomically.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix mixed whitespace and tab for define spacing.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ansuel Smith says:

====================
Multiple improvement to qca8k stability

Currently qca8337 switch are widely used on ipq8064 based router.
On these particular router it was notice a very unstable switch with
port not link detected as link with unknown speed, port dropping
randomly and general unreliability. Lots of testing and comparison
between this dsa driver and the original qsdk driver showed lack of some
additional delay and values. A main difference arised from the original
driver and the dsa one. The original driver didn't use MASTER regs to
read phy status and the dedicated mdio driver worked correctly. Now that
the dsa driver actually use these regs, it was found that these special
read/write operation required mutual exclusion to normal
qca8k_read/write operation. The add of mutex for these operation fixed
the random port dropping and now only the actual linked port randomly
dropped. Adding additional delay for set_page operation and fixing a bug
in the mdio dedicated driver fixed also this problem. The current driver
requires also more time to apply vlan switch. All of these changes and
tweak permit a now very stable and reliable dsa driver and 0 port
dropping. This series is currently tested by at least 5 user with
different routers and all reports positive results and no problems.

Changes v6:
- Fix spelling mistake
- Change ms to ns (confirmed by datasheet)
Changes v5:
- Removed mdio patch (sent separetly to try to reduce the series)
  I know it was asked to reduced this series since it big, but rework
  the new changes to skip and error check looks wrong. Since half of them
  are actually already reviewed I think it's better to keep this series as is.
- Improve rgmii configurable patch
- Move qca8k phy dedicated driver to at803x phy driver
- Add support for dedicated internal mdio driver for qca8k
Changes v4:
- Use iopoll for busy_wait function
- Better describe and split some confusing commits
- Fix bad rgmii delay configurable patch
- Drop phy generic patch to pass flags with phylink_connect_phy
- Add dsa2 patch to declare mdio node in the switch node
- Add dsa patch to permit dsa driver to declare custom get_phys_mii_mask
    Some background about the last 2 patch.
    The qca8k switch doesn't have a 1:1 map between port reg and phy reg.
    Currently it's used a function to convert port to the internal phy reg.
    I added some patch to fix this.
    - The dsa driver now check if the mdio node is present and use the of variant
      of the mdiobus_register
    - A custom phy_mii_mask is required as currently the mask is generated from
      the port reg, but in our case the mask would be different as it should be
      generated from the phy reg. To generalize this I added an extra function
      that driver can provide to pass custom phy_mii_mask.
Changes v3:
- Revert mdio writel changes (use regmap with REGCACHE disabled)
- Split propagate error patch to 4 different patch
Changes v2:
- Implemented phy driver for internal PHYs
  I'm testing cable test functions as I found some documentation that
  actually declare regs about it. Problem is that it doesn't actually
  work. It seems that the value set are ignored by the phy.
- Made the rgmii delay configurable
- Reordered patch
- Split mdio patches to more specific ones
- Reworked mdio driver to use readl/writel instead of regmap
- Reworked the entire driver to make it aware of any read/write error.
- Added phy generic patch to pass flags with phylink_connect_phy
  function
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the at803x share the same regs, it's assumed they are based on the
same implementation. Make it part of the at803x PHY driver to skip
having redudant code.
Add initial support for qca8k internal PHYs. The internal PHYs requires
special mmd and debug values to be set based on the switch revision
passwd using the dev_flags. Supports output of idle, receive and eee_wake
errors stats.
Some debug values sets can't be translated as the documentation lacks any
reference about them.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Clean any whitespace errors and fix not aligned define.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Define get_phy_flags to pass switch_Revision needed to tweak the
internal PHY with debug values based on the revision.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Improve the internal mdio read/write bus access by caching the value
without accessing it for every read/write.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Document new way of declare mapping of internal PHY to port.
The new implementation directly declare the PHY connected to the port
by adding a node in the switch node. The driver detect this and register
an internal mdiobus using the mapping defined in the mdio node.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support to setup_mdio_bus for internal phy declaration. Introduce a
flag to use the legacy port phy mapping by default and use the direct
mapping if a mdio node is detected in the switch node. Register a
dedicated mdio internal mdio bus to address the different mapping
between port and phy if the mdio node is detected.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The witch require some extra delay after setting page or the next
read/write can use still use the old page. Add a delay after the
set_page function to address this as it's done in QSDK legacy driver.
Some timeouts were notice with VLAN and phy function, enlarge the
mdio busy wait timeout to fix these problems.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MDIO_MASTER operation have a dedicated busy wait that is not protected
by the mdio mutex. This can cause situation where the MASTER operation
is done and a normal operation is executed between the MASTER read/write
and the MASTER busy_wait. Rework the qca8k_mdio_read/write function to
address this issue by binding the lock for the whole MASTER operation
and not only the mdio read/write common operation.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Clear MDIO_MASTER_EN bit from MDIO_MASTER_CTRL after read/write
operation. The MDIO_MASTER_EN bit is not reset after read/write
operation and the next operation can be wrongly interpreted by the
switch as a mdio operation. This cause a production of wrong/garbage
data from the switch and underfined bheavior. (random port drop,
unplugged port flagged with link up, wrong port speed)
Also on driver remove the MASTER_CTRL can be left set and cause the
malfunction of any next driver using the mdio device.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The legacy qsdk code used a different delay instead of the max value.
Qsdk use 1 ns for rx and 2 ns for tx. Make these values configurable
using the standard rx/tx-internal-delay-ps ethernet binding and apply
qsdk values by default. The connected gmac doesn't add any delay so no
additional delay is added to tx/rx.
On this switch the delay is actually in ns so value should be in the
1000 order. Any value converted from ps to ns by dividing it by 1000
as the switch max value for delay is 3ns.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Dsa now also supports ethernet-ports. Add this new binding as a fallback
if the ports node can't be found.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

qca8k internal phy driver require some special debug value to be set
based on the switch revision. Rework the switch id read function to
also read the chip revision.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Switch qca8327 needs special settings for the GLOBAL_FC_THRES regs.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Limit port5 rx delay to qca8337. This is taken from the legacy QSDK code
that limits the rx delay on port5 to only this particular switch version,
on other switch only the tx and rx delay for port0 are needed.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

The port 5 of the qca8337 have some problem in flood condition. The
original legacy driver had some specific buffer and priority settings
for the different port suggested by the QCA switch team. Add this
missing settings to improve switch stability under load condition.
The packet priority tweak is only needed for the qca8337 switch and
other qca8k switch are not affected.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for qca8327 in the compatible list.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qca8327 switch is a low tier version of the more recent qca8337.
It does share the same regs used by the qca8k driver and can be
supported with minimal change.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Propagate errors from qca8k_busy_wait instead of hardcoding return
value.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

qca8k_rmw can fail. Rework any user to handle error values and
correctly return. Change qca8k_rmw to return the error code or 0 instead
of the reg value. The reg returned by qca8k_rmw wasn't used anywhere,
so this doesn't cause any functional change.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

qca8k_write can fail. Rework any user to handle error values and
correctly return.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

qca8k_read can fail. Rework any user to handle error values and
correctly return.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

With a remote possibility, the set_page function can fail. Since this is
a critical part of the write/read qca8k regs, propagate the error and
terminate any read/write operation.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Put bus in local variable to improve faster access to the mdio bus.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use iopoll macro instead of while loop.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change pr_err and pr_warn to dev variant.
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add a tracepoint for capturing TCP segments with
a bad checksum. This makes it easy to identify
sources of bad frames in the fleet (e.g. machines
with faulty NICs).

It should also help tools like IOvisor's tcpdrop.py
which are used today to get detailed information
about such packets.

We don't have a socket in many cases so we must
open code the address extraction based just on
the skb.

v2: add missing export for ipv6=m
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Matteo Croce says:

====================
net: use XDP helpers

The commit 43b5169d ("net, xdp: Introduce xdp_init_buff utility
routine") and commit be9df4af ("net, xdp: Introduce xdp_prepare_buff
utility routine") introduces two useful helpers to populate xdp_buff.
Use it in drivers which still open codes that routines.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Make use of the xdp_{init,prepare}_buff() helpers instead of
an open-coded version.

Also, the field xdp->rxq was never set, so pass NULL to xdp_init_buff()
to clear it.
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make use of the xdp_{init,prepare}_buff() helpers instead of
an open-coded version.
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make use of the xdp_{init,prepare}_buff() helpers instead of
an open-coded version.
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tobias Schramm says:

====================
Add support for RK3308 gmac

The Rockchip RK3308 SoC features an internal gmac. Only the signals
required for RMII are exposed so it is limited to 10/100 Mbit/s operation.
This patchset adds support for it.
I've tested the patchset on a Rock Pi S, works fine.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The RK3308 SoC has a gmac with only the RMII interface exposed. This
commit adds it to the RK3308 dtsi.
Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Rockchip RK3308 SoC has a gmac with only the RMII interface signals
exposed.
This patch adds support for it.
Signed-off-by: Tobias Schramm <t.schramm@manjaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>