While doing high throughput test on a BQL enabled NIC,
I found a very high cost in ndo_start_xmit() when accessing BQL data.

It turned out the problem was caused by compiler trying to be
smart, but involving a bad MESI transaction :

  0.05 │  mov    0xc0(%rax),%edi    // LOAD dql->num_queued
  0.48 │  mov    %edx,0xc8(%rax)    // STORE dql->last_obj_cnt = count
 58.23 │  add    %edx,%edi
  0.58 │  cmp    %edi,0xc4(%rax)
  0.76 │  mov    %edi,0xc0(%rax)    // STORE dql->num_queued += count
  0.72 │  js     bd8

I got an incredible 10 % gain [1] by making sure cpu do not attempt
to get the cache line in Shared mode, but directly requests for
ownership.

New code :
	mov    %edx,0xc8(%rax)  // STORE dql->last_obj_cnt = count
	add    %edx,0xc0(%rax)  // RMW   dql->num_queued += count
	mov    0xc4(%rax),%ecx  // LOAD dql->adj_limit
	mov    0xc0(%rax),%edx  // LOAD dql->num_queued
	cmp    %edx,%ecx

The TX completion was running from another cpu, with high interrupts
rate.

Note that I am using barrier() as a soft hint, as mb() here could be
too heavy cost.

[1] This was a netperf TCP_STREAM with TSO disabled, but GSO enabled.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Clearly the following change is not expected:

	-       if (!cp.perfect && !cp.h)
	-               cp.alloc_hash = cp.hash;
	+       if (!cp->perfect && cp->h)
	+               cp->alloc_hash = cp->hash;

Fixes: commit 331b7292 ("net: sched: RCU cls_tcindex")
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When kmemdup() fails, we should return -ENOMEM.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hariprasad Shenai says:

====================
cxgb4: Use new BAR2 GTS for T5, adds adaptive rx and few Device ID's

This patch series adds support to use new BAR2 GTS for T5 adapter.
Adds support for adaptive rx. Remove redundant variable from a macro of
cxgb4vf driver. Adds Device ID for new adapters.

The patches series is created against 'net-next' tree.
And includes patches on cxgb4 and cxgb4vf driver.

We have included all the maintainers of respective drivers. Kindly review the
change and let us know in case of any review comments.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Based on original work by Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove redundant idx parameter of CH_DEVICE() macro, its always zero.
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use BAR2 GTS for T5. If we are on T4 use the old doorbell mechanism;
otherwise ue the new BAR2 mechanism. Use BAR2 doorbells for refilling FL's.

Based on original work by Casey Leedom <leedom@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We do not wish to disturb dropwatch or perf drop profiles with an ARP
we will ignore.
Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <hadi@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

skb->xmit_more tells us if another skb is coming next.

We need to send doorbell when : xmit_more is not set,
or txqueue is stopped (preventing next skb to come immediately)

Tested with a modified pktgen version, I got a 40% increase of
throughput.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hayes Wang says:

====================
r8152: support setting eee by ethtool

Modify some definitions about EEE, and add the support of setting
the EEE through ethtool.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Support get_eee() and set_eee() of ethtool_ops.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add functions to enable EEE and set EEE advertisement.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Replace the EEE definitions with the ones which is declared
in "mdio.h".

Chage some definitions to make them readable.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Maciej W. Rozycki says:

====================
defxx: DEFEA fixes and updates

 I have finally got my hands on an EISA variation of the board (DEC
FDDIcontroller/EISA aka DEFEA) and was able to do some testing.  Here are
initial updates to the driver that address problems I encountered so far.
More to come later on as I get back to the system that I have in a remote
location -- I need to double-check MMIO support and see what might have
been causing spurious interrupts I saw with the 8259A PIC the board's
interrupt line has been routed to.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the slot-specific I/O range for decoding accesses to PDQ ASIC
registers (IOCS0) and the discrete Burst Holdoff register (IOCS1) as per
the "HD64981F EISA Slave Interface Controller (ESIC)" datasheet.  Use
disjoint decode ranges now that the assignment of chip selects is known.
Update the span of the port I/O resource requested accordingly.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the mask rather than bit number macro to initialize the chip select
control bit for PDQ register space decoding in the Burst Holdoff register.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reverse the order of arguments to `outb', data to write comes first.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2014-09-25

1) Remove useless hash_resize_mutex in xfrm_hash_resize().
   This mutex is used only there, but xfrm_hash_resize()
   can't be called concurrently at all. From Ying Xue.

2) Extend policy hashing to prefixed policies based on
   prefix lenght thresholds. From Christophe Gouault.

3) Make the policy hash table thresholds configurable
   via netlink. From Christophe Gouault.

4) Remove the maximum authentication length for AH.
   This was needed to limit stack usage. We switched
   already to allocate space, so no need to keep the
   limit. From Herbert Xu.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Fainelli says:

====================
net: dsa: EEE and other PM features

This patch set allows DSA switch drivers to enable/disable/query EEE on a
per-port level, as well as control precisely which switch ports are
enable/disabled.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When EEE is enabled, negotiate this feature with the PHY and make sure
that the capability checking, local EEE advertisement, link partner EEE
advertisement and auto-negotiation resolution returned by phy_init_eee()
is positive, and enable EEE at the switch level.

While querying the current EEE settings, verify the low-power indication
and indicate its status.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Allow switches driver to query and enable/disable EEE on a per-port
basis by implementing the ethtool_{get,set}_eee settings and delegating
these operations to the switch driver.

set_eee() will need to coordinate with the PHY driver to make sure that
EEE is enabled, the link-partner supports it and the auto-negotiation
result is satisfactory.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The SF2 switch driver is already architected around per-port
enable/disable callbacks, so we just need a slight update to our
existing bcm_sf2_port_setup() resp. bcm_sf2_port_disable() functions to
be suitable as callbacks for port_enable/port_disable.

We need to shuffle a little the code that does the per-port VLAN
configuration/isolation since ports can now be brought up/down
separately, so we need to make sure that IMP (CPU, management) port is
always included in that specific port setup.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the link is down, disable the RGMII interface to conserve as much
power as possible. We re-enable the RGMII interface whenever the link is
detected.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Whenever a per-port network device is used/unused, invoke the switch
driver port_enable/port_disable callbacks to allow saving as much power
as possible by disabling unused parts of the switch (RX/TX logic, memory
arrays, PHYs...). We supply a PHY device argument to make sure the
switch driver can act on the PHY device if needed (like putting/taking
the PHY out of deep low power mode).
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dsa_slave_open() should start the PHY library state machine for its PHY
interface, and dsa_slave_close() should stop the PHY library state
machine accordingly.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is a cleanup which follows the idea in commit e11ecddf (tcp: use
TCP_SKB_CB(skb)->tcp_flags in input path),
and it may reduce register pressure since skb->cb[] access is fast,
bacause skb is probably in a register.

v2: remove variable th
v3: reword the changelog
Signed-off-by: Weiping Pan <panweiping3@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Our goal is to access no more than one cache line access per skb in
a write or receive queue when doing the various walks.

After recent TCP_SKB_CB() reorganizations, it is almost done.

Last part is tcp_skb_pcount() which currently uses
skb_shinfo(skb)->gso_segs, which is a terrible choice, because it needs
3 cache lines in current kernel (skb->head, skb->end, and
shinfo->gso_segs are all in 3 different cache lines, far from skb->cb)

This very simple patch reuses space currently taken by tcp_tw_isn
only in input path, as tcp_skb_pcount is only needed for skb stored in
write queue.

This considerably speeds up tcp_ack(), granted we avoid shinfo->tx_flags
to get SKBTX_ACK_TSTAMP, which seems possible.

This also speeds up all sack processing in general.

This speeds up tcp_sendmsg() because it no longer has to access/dirty
shinfo.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: better TCP_SKB_CB layout

TCP had the assumption that IPCB and IP6CB are first members of skb->cb[]

This is fine, except that IPCB/IP6CB are used in TCP for a very short time
in input path.

What really matters for TCP stack is to get skb->next,
TCP_SKB_CB(skb)->seq, and TCP_SKB_CB(skb)->end_seq in the same cache line.

skb that are immediately consumed do not care because whole skb->cb[] is
hot in cpu cache, while skb that sit in wocket write queue or receive queues
do not need TCP_SKB_CB(skb)->header at all.

This patch set implements the prereq for IPv4, IPv6, and TCP to make this
possible. This makes TCP more efficient.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

TCP maintains lists of skb in write queue, and in receive queues
(in order and out of order queues)

Scanning these lists both in input and output path usually requires
access to skb->next, TCP_SKB_CB(skb)->seq, and TCP_SKB_CB(skb)->end_seq

These fields are currently in two different cache lines, meaning we
waste lot of memory bandwidth when these queues are big and flows
have either packet drops or packet reorders.

We can move TCP_SKB_CB(skb)->header at the end of TCP_SKB_CB, because
this header is not used in fast path. This allows TCP to search much faster
in the skb lists.

Even with regular flows, we save one cache line miss in fast path.

Thanks to Christoph Paasch for noticing we need to cleanup
skb->cb[] (IPCB/IP6CB) before entering IP stack in tx path,
and that I forgot IPCB use in tcp_v4_hnd_req() and tcp_v4_save_options().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6_opt_accepted() assumes IP6CB(skb) holds the struct inet6_skb_parm
that it needs. Lets not assume this, as TCP stack might use a different
place.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip_options_echo() assumes struct ip_options is provided in &IPCB(skb)->opt
Lets break this assumption, but provide a helper to not change all call points.

ip_send_unicast_reply() gets a new struct ip_options pointer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Cache skb_shinfo(skb) in a variable to avoid computing it multiple
times.

Reorganize the tests to remove one indentation level.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

BPF_LD | BPF_W | BPF_LEN instruction is occasionally used by tcpdump
and present in 11 tests in lib/test_bpf.c
Teach sparc JIT compiler to emit it.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bcmgenet_wol_resume() is only used in bcmgenet_resume(), which is only
defined when CONFIG_PM_SLEEP is enabled. This leads to the following
compile warning when building with !CONFIG_PM_SLEEP:

drivers/net/ethernet/broadcom/genet/bcmgenet.c:1967:12: warning: ‘bcmgenet_wol_resume’ defined but not used [-Wunused-function]

Since bcmgenet_resume() is the only user of bcmgenet_wol_resume(), fix
this by directly inlining the function there.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove the duplicated comment
"/* The following definitions are for users of the vport subsytem: */"
in vport.h
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2014-09-23

This patch series adds support for the FM10000 Ethernet switch host
interface.  The Intel FM10000 Ethernet Switch is a 48-port Ethernet switch
supporting both Ethernet ports and PCI Express host interfaces.  The fm10k
driver provides support for the host interface portion of the switch, both
PF and VF.

As the host interfaces are directly connected to the switch this results in
some significant differences versus a standard network driver.  For example
there is no PHY or MII on the device.  Since packets are delivered directly
from the switch to the host interface these are unnecessary.  Otherwise most
of the functionality is very similar to our other network drivers such as
ixgbe or igb.  For example we support all the standard network offloads,
jumbo frames, SR-IOV (64 VFS), PTP, and some VXLAN and NVGRE offloads.

v2: converted dev_consume_skb_any() to dev_kfree_skb_any()
    fix up PTP code based on feedback from the community
v3: converted the use of smb_mb__before_clear_bit() to smb_mb__before_atomic()
    added vmalloc header to patch 15
    added prefetch header to patch 16
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

csum_partial() is a generic function which is not optimised for small fixed
length calculations, and its use requires to store "from" and "to" values in
memory while we already have them available in registers. This also has impact,
especially on RISC processors. In the same spirit as the change done by
Eric Dumazet on csum_replace2(), this patch rewrites inet_proto_csum_replace4()
taking into account RFC1624.

I spotted during a NATted tcp transfert that csum_partial() is one of top 5
consuming functions (around 8%), and the second user of csum_partial() is
inet_proto_csum_replace4().
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

csum_partial() is a generic function which is not optimised for small fixed
length calculations, and its use requires to store "from" and "to" values in
memory while we already have them available in registers. This also has impact,
especially on RISC processors. In the same spirit as the change done by
Eric Dumazet on csum_replace2(), this patch rewrites inet_proto_csum_replace4()
taking into account RFC1624.

I spotted during a NATted tcp transfert that csum_partial() is one of top 5
consuming functions (around 8%), and the second user of csum_partial() is
inet_proto_csum_replace4().

I have proposed the same modification to inet_proto_csum_replace4() in another
patch.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>