From what I can tell the practical limitation on the size of the Tx data
buffer is the fact that the Tx descriptor is limited to 14 bits.  As such
we cannot use 16K as is typically used on the other Intel drivers.  However
artificially limiting ourselves to 8K can be expensive as this means that
we will consume up to 10 descriptors (1 context, 1 for header, and 9 for
payload, non-8K aligned) in a single send.

I propose that we can reduce this by increasing the maximum data for a 4K
aligned block to 12K.  We can reduce the descriptors used for a 32K aligned
block by 1 by increasing the size like this.  In addition we still have the
4K - 1 of space that is still unused.  We can use this as a bit of extra
padding when dealing with data that is not aligned to 4K.

By aligning the descriptors after the first to 4K we can improve the
efficiency of PCIe accesses as we can avoid using byte enables and can fetch
full TLP transactions after the first fetch of the buffer.  This helps to
improve PCIe efficiency.  Below is the results of testing before and after
with this patch:

Recv   Send   Send                         Utilization      Service Demand
Socket Socket Message  Elapsed             Send     Recv    Send    Recv
Size   Size   Size     Time    Throughput  local    remote  local   remote
bytes  bytes  bytes    secs.   10^6bits/s  % S      % U     us/KB   us/KB
Before:
87380  16384  16384    10.00     33682.24  20.27    -1.00   0.592   -1.00
After:
87380  16384  16384    10.00     34204.08  20.54    -1.00   0.590   -1.00

So the net result of this patch is that we have a small gain in throughput
due to a reduction in overhead for putting together the frame.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Calling dev_close() causes IFF_UP to be cleared which will remove the
interfaces routes and some addresses. That's probably not what the user
intended when running the offline selftest. Besides this does not happen
if the interface is brought down before the test, so the current
behaviour is inconsistent.
Instead call the net_device_ops ndo_stop function directly and avoid
touching IFF_UP at all.
Signed-off-by: Stefan Assmann <sassmann@kpanic.de>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Eric Dumazet says:

====================
net: various udp/tcp changes

First round of patches for linux-4.7

Add a generic facility for sockets to be freed after an RCU grace
period, if they need to.

Then UDP stack is changed to no longer use SLAB_DESTROY_BY_RCU,
in order to speedup rx processing for traffic encapsulated in UDP.
It gives a 17 % speedup for normal UDP reception in stress conditions.

Then TCP listeners are changed to use SOCK_RCU_FREE as well
to avoid touching sk_refcnt in synflood case :
I got up to 30 % performance increase for a mono listener.

Then three patches add SK_MEMINFO_DROPS to sock_diag
and add per socket rx drops accounting to TCP.

Last patch adds rate limiting on ACK sent on behalf of SYN_RECV
to better resist to SYNFLOOD targeting one or few flows.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Attackers like to use SYNFLOOD targeting one 5-tuple, as they
hit a single RX queue (and cpu) on the victim.

If they use random sequence numbers in their SYN, we detect
they do not match the expected window and send back an ACK.

This patch adds a rate limitation, so that the effect of such
attacks is limited to ingress only.

We roughly double our ability to absorb such attacks.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

TCP uses per cpu 'sockets' to send some packets :
- RST packets ( tcp_v4_send_reset()) )
- ACK packets for SYN_RECV and TIMEWAIT sockets

By setting SOCK_USE_WRITE_QUEUE flag, we tell sock_wfree()
to not call sk_write_space() since these internal sockets
do not care.

This gives a small performance improvement, merely by allowing
cpu to properly predict the sock_wfree() conditional branch,
and avoiding one atomic operation.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Goal: packets dropped by a listener are accounted for.

This adds tcp_listendrop() helper, and clears sk_drops in sk_clone_lock()
so that children do not inherit their parent drop count.

Note that we no longer increment LINUX_MIB_LISTENDROPS counter when
sending a SYNCOOKIE, since the SYN packet generated a SYNACK.
We already have a separate LINUX_MIB_SYNCOOKIESSENT
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Now ss can report sk_drops, we can instruct TCP to increment
this per socket counter when it drops an incoming frame, to refine
monitoring and debugging.

Following patch takes care of listeners drops.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reporting sk_drops to user space was available for UDP
sockets using /proc interface.

Add this to sock_diag, so that we can have the same information
available to ss users, and we'll be able to add sk_drops
indications for TCP sockets as well.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a SYNFLOOD targets a non SO_REUSEPORT listener, multiple
cpus contend on sk->sk_refcnt and sk->sk_wmem_alloc changes.

By letting listeners use SOCK_RCU_FREE infrastructure,
we can relax TCP_LISTEN lookup rules and avoid touching sk_refcnt

Note that we still use SLAB_DESTROY_BY_RCU rules for other sockets,
only listeners are impacted by this change.

Peak performance under SYNFLOOD is increased by ~33% :

On my test machine, I could process 3.2 Mpps instead of 2.4 Mpps

Most consuming functions are now skb_set_owner_w() and sock_wfree()
contending on sk->sk_wmem_alloc when cooking SYNACK and freeing them.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We'll soon no longer take a refcount on listeners,
so reqsk_alloc() can not assume a listener refcount is not
zero. We need to use atomic_inc_not_zero()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

RX packet processing holds rcu_read_lock(), so we can remove
pairs of rcu_read_lock()/rcu_read_unlock() in lookup functions
if inet_diag also holds rcu before calling them.

This is needed anyway as __inet_lookup_listener() and
inet6_lookup_listener() will soon no longer increment
refcount on the found listener.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since linux 2.6.29, lookups only use rcu locking.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tom Herbert would like not touching UDP socket refcnt for encapsulated
traffic. For this to happen, we need to use normal RCU rules, with a grace
period before freeing a socket. UDP sockets are not short lived in the
high usage case, so the added cost of call_rcu() should not be a concern.

This actually removes a lot of complexity in UDP stack.

Multicast receives no longer need to hold a bucket spinlock.

Note that ip early demux still needs to take a reference on the socket.

Same remark for functions used by xt_socket and xt_PROXY netfilter modules,
but this might be changed later.

Performance for a single UDP socket receiving flood traffic from
many RX queues/cpus.

Simple udp_rx using simple recvfrom() loop :
438 kpps instead of 374 kpps : 17 % increase of the peak rate.

v2: Addressed Willem de Bruijn feedback in multicast handling
 - keep early demux break in __udp4_lib_demux_lookup()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Cc: Willem de Bruijn <willemb@google.com>
Tested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We want a generic way to insert an RCU grace period before socket
freeing for cases where RCU_SLAB_DESTROY_BY_RCU is adding too
much overhead.

SLAB_DESTROY_BY_RCU strict rules force us to take a reference
on the socket sk_refcnt, and it is a performance problem for UDP
encapsulation, or TCP synflood behavior, as many CPUs might
attempt the atomic operations on a shared sk_refcnt

UDP sockets and TCP listeners can set SOCK_RCU_FREE so that their
lookup can use traditional RCU rules, without refcount changes.
They can set the flag only once hashed and visible by other cpus.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Tested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
10GbE Intel Wired LAN Driver Updates 2016-04-04

This series contains updates to ixgbe and ixgbevf.

Pavel Tikhomirov fixes a typo where we were incrementing transmit stats
instead of receive stats on the receive side.

Emil updates the ixgbevf driver to use bit operations for setting and
checking the adapter state.

Chas Williams adds the new NDO trust feature check so that the VF guest
has the ability to set the unicast address of the interface, if it is a
trusted VF.

Alex cleans up the driver to that the only time we add a PF entry to the
VLVF is either for VLAN 0 or if the PF has requested a VLAN that a VF
is already using.  Also adds support for generic transmit checksums,
giving the added advantage is that we can support inner checksum offloads
for tunnels and MPLS while still being able to transparently insert
VLAN tags.  Lastly, changed ixgbe so that we can use the ethtool
rx-vlan-filter flag to toggle receive VLAN filtering on and off.

Mark cleans up the ixgbe driver by making all op structures that do not
change constants.  Also fixed flow control for Xeon D KR backplanes, since
we cannot use auto-negotiation to determine the mode, we have to use
whatever the user configured.

Sowmini Varadhan updates ixgbe to use eth_platform_get_mac_address()
instead of the arch specific solution that was added by a previous
commit.

Don fixed an issue where it was possible that a system reset could occur
when we were holding the SWFW semaphore lock, which the next time the
driver loaded would see it incorrectly as locked.

v2: updated patch 8 of the series to include a minor flags issue where
    we had lost NETIF_F_HW_TC and we were setting NETIF_F_SCTP_CRC in
    two different areas, when we only needed/wanted it in one spot.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Vivien Didelot says:

====================
net: dsa: mv88e6131: HW bridging support for 6185

All packets passing through a switch of the 6185 family are currently all
directed to the CPU port. This means that port bridging is software driven.

To enable hardware bridging for this switch family, we need to implement the
port mapping operations, the FDB operations, and optionally the VLAN operations
(for 802.1Q and VLAN filtering aware systems).

However this family only has 256 FDBs indexed by 8-bit identifiers, opposed to
4096 FDBs with 12-bit identifiers for other families such as 6352. It also
doesn't have dedicated FID registers for ATU and VTU operations.

This patchset fixes these differences, and enable hardware bridging for 6185.

Changes v1 -> v2:
 - Describe the different numbers of databases and prefer a feature-based logic
   over the current ID/family-based logic.
====================
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

By adding support for bridge operations, FDB operations, and optionally
VLAN operations (for 802.1Q and VLAN filtering aware systems), the
switch bridges ports correctly, the CPU is able to populate the hardware
address databases, and thus hardware bridging becomes functional within
the 88E6185 family of switches.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 88E6185 switch also has a MapDA bit in its Port Control 2 register.
When this bit is cleared, all frames are sent out to the CPU port.

Set this bit to rely on address databases (ATU) hits and direct frames
out of the correct ports, and thus allow hardware bridging.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The 6185 family of devices has only 256 address databases. Their 8-bit
FID for ATU and VTU operations are split into ATU Control and ATU/VTU
Operation registers.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Marvell switch chips have different number of address databases.

The code currently only supports models with 4096 databases. Such switch
has dedicated FID registers for ATU and VTU operations. Models with
fewer databases have their FID split in several registers.

List them all but only support models with 4096 databases at the moment.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Only switch families with 4096 address databases have dedicated FID
registers for ATU and VTU operations.

Factorize the access to the GLOBAL_ATU_FID register and introduce a
mv88e6xxx_has_fid_reg() helper function to protect the access to
GLOBAL_ATU_FID and GLOBAL_VTU_FID.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Introduce a mv88e6xxx_has_stu() helper to protect the access to the
GLOBAL_VTU_SID register, instead of checking switch families.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This change makes it so that we can use the ethtool rx-vlan-filter flag to
toggle Rx VLAN filtering on and off.  This is basically just an extension
of the existing VLAN promisc work in that it just adds support for the
additional ethtool flag.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Added support to match on UDP fields in the transport layer.
Extended core logic to support multiple headers.

Verified with the following filters :

	handle 1: u32 divisor 1
	u32 ht 800: order 1 link 1: \
	offset at 0 mask 0f00 shift 6 plus 0 eat match ip protocol 6 ff
	u32 ht 1: order 2 \
	match tcp src 1024 ffff match tcp dst 23 ffff action drop
	handle 2: u32 divisor 1
	u32 ht 800: order 3 link 2: \
	offset at 0 mask 0f00 shift 6 plus 0 eat match ip protocol 17 ff
	u32 ht 2: order 4 \
	match udp src 1025 ffff match udp dst 24 ffff action drop
Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

It is possible on some HW that a system reset could occur when we are
holding the SWFW semaphore lock.  So next time the driver was loaded we
would see it incorrectly as locked. This patch will recover from that state
by: Attempting to acquire the semaphore and then regardless of whether or
not it was acquire we immediately release it. This will force us into
a known good state.
Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This commit adds a callback which allows to adjust the maximum transmit
bitrate the card can output. This makes it possible to get a smooth
traffic instead of the default burst-y behaviour when trying to output
e.g. a video stream.

Much of the logic needed to get a correct bcnrc_val was taken from the
ixgbe_set_vf_rate_limit() function.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Xeon D KR backplane is different from other backplanes,
in that we can't use auto-negotiation to determine the
mode. Instead, use whatever the user configured.
Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds support for generic Tx checksums to the ixgbevf driver.  It
turns out this is actually pretty easy after going over the datasheet as we
were doing a number of steps we didn't need to.

In order to perform a Tx checksum for an L4 header we need to fill in the
following fields in the Tx descriptor:
  MACLEN (maximum of 127), retrieved from:
		skb_network_offset()
  IPLEN  (maximum of 511), retrieved from:
		skb_checksum_start_offset() - skb_network_offset()
  TUCMD.L4T indicates offset and if checksum or crc32c, based on:
		skb->csum_offset

The added advantage to doing this is that we can support inner checksum
offloads for tunnels and MPLS while still being able to transparently
insert VLAN tags.

I also took the opportunity to clean-up many of the feature flag
configuration bits to make them a bit more consistent between drivers.  In
the case of the VF drivers this meant adding support for SCTP CRCs, and
inner checksum offloads for MPLS and various tunnel types.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds support for generic Tx checksums to the ixgbe driver.  It
turns out this is actually pretty easy after going over the datasheet as we
were doing a number of steps we didn't need to.

In order to perform a Tx checksum for an L4 header we need to fill in the
following fields in the Tx descriptor:
  MACLEN (maximum of 127), retrieved from:
		skb_network_offset()
  IPLEN  (maximum of 511), retrieved from:
		skb_checksum_start_offset() - skb_network_offset()
  TUCMD.L4T indicates offset and if checksum or crc32c, based on:
		skb->csum_offset

The added advantage to doing this is that we can support inner checksum
offloads for tunnels and MPLS while still being able to transparently
insert VLAN tags.

I also took the opportunity to clean-up many of the feature flag
configuration bits to make them a bit more consistent between drivers.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

This commit converts commit c762dff2 ("ixgbe: Look up MAC address in
Open Firmware or IDPROM") to use eth_platform_get_mac_address()
added by commit c7f5d105 ("net: Add eth_platform_get_mac_address()
helper.")
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The source for the ops structure contents are const, so make them
so. Copy them in place with structure assignments instead of memcpys.
Make the mbx_ops accessed by reference instead of making a copy of
the source structure. Update copyright date on the touched files.
Reported-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

We were adding VLAN 0 twice each time we restored the VLAN configuration.
Instead of doing it twice we can just start working through the active
VLANs from ID 1 on and skip the double write.
Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Remove the sh-irda driver as it appears to be unused since
c0bb9b30 ("ARCH: ARM: shmobile: Remove ag5evm board support").
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Moritz Fischer says:

====================
macb: Codingstyle cleanups

resending almost unchanged v2 here:

Changes from v2:
* Rebased onto net-next
* Changed 5th patches commit message
* Added Nicholas' and Michal's Acked-Bys

Changes from v1:
* Backed out variable scope changes
* Separated out ether_addr_copy into it's own commit
* Fixed typo in comments as suggested by Joe
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Checkpatch suggests using ether_addr_copy over memcpy
to copy the mac address.
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This commit deals with a bunch of checkpatch suggestions
that without changing behavior make checkpatch happier.
Acked-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This commit takes care of the coding style warnings
that are mostly due to a different comment style and
lines over 80 chars, as well as a dangling else.
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

checkpatch.pl gave the following error:

ERROR: space required before the open parenthesis '('
+	for(; p < end; p++, offset += 4)
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch supports the following interrupts.

- One interrupt for multiple (timestamp, error, gPTP)
- One interrupt for emac
- Four interrupts for dma queue (best effort rx/tx, network control rx/tx)

This patch improve efficiency of the interrupt handler by adding the
interrupt handler corresponding to each interrupt source described
above. Additionally, it reduces the number of times of the access to
EthernetAVB IF.
Also this patch prevent this driver depends on the whim of a boot loader.

[ykaneko0929@gmail.com: define bit names of registers]
[ykaneko0929@gmail.com: add comment for gen3 only registers]
[ykaneko0929@gmail.com: fix coding style]
[ykaneko0929@gmail.com: update changelog]
[ykaneko0929@gmail.com: gen3: fix initialization of interrupts]
[ykaneko0929@gmail.com: gen3: fix clearing interrupts]
[ykaneko0929@gmail.com: gen3: add helper function for request_irq()]
[ykaneko0929@gmail.com: gen3: remove IRQF_SHARED flag for request_irq()]
[ykaneko0929@gmail.com: revert ravb_close() and ravb_ptp_stop()]
[ykaneko0929@gmail.com: avoid calling free_irq() to non-hooked interrupts]
[ykaneko0929@gmail.com: make NC/BE interrupt handler a function]
[ykaneko0929@gmail.com: make timestamp interrupt handler a function]
[ykaneko0929@gmail.com: timestamp interrupt is handled in multiple
 interrupt handler instead of dma queue interrupt handler]
Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>