This patch adds busy poll support to epoll. The implementation is meant to
be opportunistic in that it will take the NAPI ID from the last socket
that is added to the ready list that contains a valid NAPI ID and it will
use that for busy polling until the ready list goes empty.  Once the ready
list goes empty the NAPI ID is reset and busy polling is disabled until a
new socket is added to the ready list.

In addition when we insert a new socket into the epoll we record the NAPI
ID and assume we are going to receive events on it.  If that doesn't occur
it will be evicted as the active NAPI ID and we will resume normal
behavior.

An application can use SO_INCOMING_CPU or SO_REUSEPORT_ATTACH_C/EBPF socket
options to spread the incoming connections to specific worker threads
based on the incoming queue. This enables epoll for each worker thread
to have only sockets that receive packets from a single queue. So when an
application calls epoll_wait() and there are no events available to report,
busy polling is done on the associated queue to pull the packets.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move the core functionality in sk_busy_loop() to napi_busy_loop() and
make it independent of sk.

This enables re-using this function in epoll busy loop implementation.
Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch flips the logic we were using to determine if the busy polling
has timed out.  The main motivation for this is that we will need to
support two different possible timeout values in the future and by
recording the start time rather than when we would want to end we can focus
on making the end_time specific to the task be it epoll or socket based
polling.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

checking the return value of sk_busy_loop. As there are only a few
consumers of that data, and the data being checked for can be replaced
with a check for !skb_queue_empty() we might as well just pull the code
out of sk_busy_loop and place it in the spots that actually need it.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of defining two versions of skb_mark_napi_id I think it is more
readable to just match the format of the sk_mark_napi_id functions and just
wrap the contents of the function instead of defining two versions of the
function.  This way we can save a few lines of code since we only need 2 of
the ifdef/endif but needed 5 for the extra function declaration.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While working on some recent busy poll changes we found that child sockets
were being instantiated without NAPI ID being set.  In our first attempt to
fix it, it was suggested that we should just pull programming the NAPI ID
into the function itself since all callers will need to have it set.

In addition to the NAPI ID change I have dropped the code that was
populating the Rx hash since it was actually being populated in
tcp_get_cookie_sock.
Reported-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch is a cleanup/fix for NAPI IDs following the changes that made it
so that sender_cpu and napi_id were doing a better job of sharing the same
location in the sk_buff.

One issue I found is that we weren't validating the napi_id as being valid
before we started trying to setup the busy polling.  This change corrects
that by using the MIN_NAPI_ID value that is now used in both allocating the
NAPI IDs, as well as validating them.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
Mellanox mlx5e XDP performance optimization

This series provides some preformancee optimizations for mlx5e
driver, especially for XDP TX flows.

1st patch is a simple change of rmb to dma_rmb in CQE fetch routine
which shows a huge gain for both RX and TX packet rates.

2nd patch removes write combining logic from the driver TX handler
and simplifies the TX logic while improving TX CPU utilization.

All other patches combined provide some refactoring to the driver TX
flows to allow some significant XDP TX improvements.

More details and performance numbers per patch can be found in each patch
commit message compared to the preceding patch.

Overall performance improvemnets
  System: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz

Test case                   Baseline      Now      improvement
---------------------------------------------------------------
TX packets (24 threads)     45Mpps        54Mpps      20%
TC stack Drop (1 core)      3.45Mpps      3.6Mpps     5%
XDP Drop      (1 core)      14Mpps        16.9Mpps    20%
XDP TX        (1 core)      10.4Mpps      13.7Mpps    31%
====================
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Different SQ types (tx, xdp, ico) are growing apart, we separate them
and remove unwanted parts in each one of them, to simplify data path and
utilize data cache.

Remove DB union from SQ structures since it is not needed anymore as we
now have different SQ data type for each SQ.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the next patches we will introduce different SQ types,
and we would want to reuse those functions, in this patch we make them
agnostic to SQ type (txq, xdp, ico).
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rename mlx5e_{create,destroy}_{sq,rq,cq} to
mlx5e_{alloc,free}_{sq,rq,cq}.

Rename mlx5e_{enable,disable}_{sq,rq,cq} to
mlx5e_{create,destroy}_{sq,rq,cq}.

mlx5e_{enable,disable}_{sq,rq,cq} used to actually create/destroy the SQ
in FW, so we rename them to align the functions names with FW semantics.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the next patches we will introduce different SQ types, for that we here
generalize some TX helper functions to work with more basic SQ parameters,
in order to re-use them for the different SQ types.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

XDP SQ has a fixed size WQE (MLX5E_XDP_TX_WQEBBS = 1) and only posts
one kind of WQE (MLX5_OPCODE_SEND),

Also we initialize SQ descriptors static fields once on open_xdpsq,
rather than every time on critical path.

Optimize the code in light of those facts and add a prefetch of the TX
descriptor first thing in the xdp xmit function.

Performance improvement:
System: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz

Test case              Before     Now        improvement
---------------------------------------------------------------
XDP TX   (1 core)      13Mpps    13.7Mpps       5%
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Handle XDP TX completions before handling RX packets, to make sure more
free space is available for XDP TX packets a moment before handling
RX packets.

Performance improvement:
System: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz

Test case              Before     Now      improvement
---------------------------------------------------------------
XDP Drop (1 core)      16.9Mpps  16.9Mpps    No change
XDP TX   (1 core)      12Mpps    13Mpps      8%
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

To save many rq->channel->sq dereferences in fast-path.
And rename it to xdpsq.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move struct mlx5e_rq and friends to appear after mlx5e_sq declaration in
en.h.

We will need this for next patch to move the mlx5e_sq instance into
mlx5e_rq struct for XDP SQs.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

XDP code belongs to RX path, move mlx5e_poll_xdp_tx_cq and
mlx5e_free_xdp_tx_descs to en_rx.c.

Rename them to mlx5e_poll_xdpsq_cq and mlx5e_free_xdpsq_descs.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

One is sufficient since Blue Flame is not supported anymore.
This will also come in handy for switchdev mode to save resources, since
VF representors will use same single UAR as well for their own SQs.
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

mlx5e netdev Blue Flame (write combining) support demands a lot of
overhead for a little latency gain for some special cases, this overhead
is hurting the common case.

Here we remove xmit Blue Flame support by creating all bfregs with no
write combining for all SQs, and we remove a lot of BF logic and
conditions from xmit data path.

Simplify mlx5e_tx_notify_hw (doorbell function) by removing BF related
code and by removing one memory barrier needed for WC mapped SQ doorbell
buffers, which no longer exist.

Performance improvement:
System: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz

Test case                   Before      Now      improvement
---------------------------------------------------------------
TX packets (24 threads)     50Mpps      54Mpps    8%
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use dma_rmb in mlx5e_get_cqe rather than aggressive rmb (at least on
some architectures), this should help improve the performance on such
CPU archs where dma_rmb is optimized.

Performance improvement:
System: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz

Test case                   Baseline      Now      improvement
---------------------------------------------------------------
TX packets (24 threads)     45Mpps        50Mpps      11%
TC stack Drop (1 core)      3.45Mpps      3.6Mpps     5%
XDP Drop      (1 core)      14Mpps        16.9Mpps    20%
XDP TX        (1 core)      10.4Mpps      12Mpps      15%
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bcm_sf2 does require the MDIO_BCM_UNIMAC driver which is now dependent
on OF_MDIO but also internally uses of_mdio.c provided routines which
are guarted with OF_MDIO.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Fixes: 90eff909 ("net: phy: Allow splitting MDIO bus/device support from PHYs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

David Lebrun says:

====================
Performances improvement for IPv6 Segment Routing

This patch series improves the performances of IPv6 SR by optimizing skb head
reallocation and extending the use of dst_cache. The overall performances improve
by 35%.

Before patch series (SRH encap):
Result: OK: 7348320(c7347271+d1048) usec, 5000000 (1000byte,0frags)
  680427pps 5443Mb/sec (5443416000bps) errors: 0

After patch series (SRH encap):
Result: OK: 4774543(c4774084+d459) usec, 5000000 (1000byte,0frags)
  1047220pps 8377Mb/sec (8377760000bps) errors: 0

Baseline for plain IPv6 forwarding:
Result: OK: 4244144(c4243722+d422) usec, 5000000 (1000byte,0frags)
  1178093pps 9424Mb/sec (9424744000bps) errors: 0
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

We already use dst_cache in seg6_output, when handling locally generated
packets. We extend it in seg6_input, to also handle forwarded packets, and avoid
unnecessary fib lookups.

Performances for SRH encapsulation before the patch:
Result: OK: 5656067(c5655678+d388) usec, 5000000 (1000byte,0frags)
  884006pps 7072Mb/sec (7072048000bps) errors: 0

Performances after the patch:
Result: OK: 4774543(c4774084+d459) usec, 5000000 (1000byte,0frags)
  1047220pps 8377Mb/sec (8377760000bps) errors: 0
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

To insert or encapsulate a packet with an SRH, we need a large enough skb
headroom. Currently, we are using pskb_expand_head to inconditionally increase
the size of the headroom by the amount needed by the SRH (and IPv6 header).
If this reallocation is performed by another CPU than the one that initially
allocated the skb, then when the initial CPU kfree the skb, it will enter the
__slab_free slowpath, impacting performances.

This patch replaces pskb_expand_head with skb_cow_head, that will reallocate the
skb head only if the headroom is not large enough.

Performances for SRH encapsulation before the patch:
Result: OK: 7348320(c7347271+d1048) usec, 5000000 (1000byte,0frags)
  680427pps 5443Mb/sec (5443416000bps) errors: 0

Performances after the patch:
Result: OK: 5656067(c5655678+d388) usec, 5000000 (1000byte,0frags)
  884006pps 7072Mb/sec (7072048000bps) errors: 0
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use setup_deferrable_timer() instead of init_timer_deferrable() to
simplify the code.
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jiri Pirko says:

====================
mlxsw: Query resources from firmware

Ido says:

Some parts of the driver already use the resource query mechanism, but
in other parts we still rely on hard coded values that may change over
time.

This patchset removes most of these remaining values and queries them
from the firmware instead.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

As explained in the previous patch, the cell size may change in future
devices, so query it from the firmware instead of hard coding it.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The sizes and thresholds of the priority group (PG) buffers are
configured in cells, which represent a specific amount of bytes.

The cell size can vary in different devices, so it's better to query it
from the firmware than hard coding it.

Refactor the code dealing with this value into different functions, so
that it will be easier to make the conversion in the next patch.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of hard coding the size of the shared buffer in the driver,
query it from the firmware, as it may change in future devices.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We currently hard code the maximum number of ports in the driver, but
this may change in future devices, so query it from the firmware
instead.

Fallback to a maximum of 64 ports in case this number can't be queried.
This should only happen in SwitchX-2 for which this number is correct.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of hard coding the number of LPM trees in the driver, query it
from the firmware, as it may change in future devices.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
40GbE Intel Wired LAN Driver Updates 2017-03-23

This series contains updates to i40e and i40e.txt documentation.

Jake provides all the changes in the series which are centered around
ntuple filter fixes and additional support.  Fixed the current
implementation of .set_rxnfc, where we were not reading the mask field
for filter entries which was resulting in filters not behaving as
expected and not working correctly.  When cleaning up after disabling
flow director support, ensure that the default input set is correctly
reprogrammed.  Since the hardware only supports a single input set for
all flows of that type, the driver shall only allow the input set to
change if there are no other configured filters for that flow type, so
add support to detect when we can update the input set for each flow
type.  Align the driver to other drivers to partition the ring_cookie
value into 8bits of VF index, along with 32bits of queue number instead
of using the user-def field.  Added support to parse the user-def field
into a data structure format to allow future extensions of the user-def
filed by keeping all the code that read/writes the field into a single
location.  Added support for flexible payloads passed via ethtool
user-def field.  We support a single flexible word (2byte) value per
protocol type, and we handle the FLX_PIT register using a list of
flexible entries so that each flow type may be configured separately.
Enabled flow director filters for SCTPv4 packets using the ethtool
ntuple interface to enable filters.  Updated the documentation on the
i40e driver to include the newly added support to ntuple filters.
Reduced complexity of a if-continue-else-break section of code by
taking advantage of using hlist_for_each_entry_continue() instead.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix copy and paste error setting rt_ttl_propagate.

Fixes: 5b441ac8 ("mpls: allow TTL propagation to IP packets to be configured")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Because sysctl_tcp_adv_win_scale could be changed any time, so there
is one race in tcp_win_from_space.
For example,
1.sysctl_tcp_adv_win_scale<=0 (sysctl_tcp_adv_win_scale is negative now)
2.space>>(-sysctl_tcp_adv_win_scale) (sysctl_tcp_adv_win_scale is postive now)

As a result, tcp_win_from_space returns 0. It is unexpected.

Certainly if the compiler put the sysctl_tcp_adv_win_scale into one
register firstly, then use the register directly, it would be ok.
But we could not depend on the compiler behavior.
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Converting IPv4 address doesn't need 64-bit arithmetic.

Space savings: 10 bytes!

	add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-10 (-10)
	function                          old     new   delta
	in_aton                            96      86     -10
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The PF driver is incorrectly resetting Octeon when the module parameter
"fw_type=none" is there.  "fw_type=none" means the PF should not load any
firmware to the NIC because Octeon is already running preloaded firmware.

Fix it by putting an if (fw_type != none) around the reset code.

Because the Octeon reset is now conditionally gone, when unloading the
driver, conditionally send the RESET_PF command to the firmware who will
then free up PF-related data structures.
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: Satanand Burla <satananda.burla@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Certain system process significant unconnected UDP workload.
It would be preferrable to disable UDP early demux for those systems
and enable it for TCP only.

By disabling UDP demux, we see these slight gains on an ARM64 system-
782 -> 788Mbps unconnected single stream UDPv4
633 -> 654Mbps unconnected UDPv4 different sources

The performance impact can change based on CPU architecure and cache
sizes. There will not much difference seen if entire UDP hash table
is in cache.

Both sysctls are enabled by default to preserve existing behavior.

v1->v2: Change function pointer instead of adding conditional as
suggested by Stephen.

v2->v3: Read once in callers to avoid issues due to compiler
optimizations. Also update commit message with the tests.

v3->v4: Store and use read once result instead of querying pointer
again incorrectly.

v4->v5: Refactor to avoid errors due to compilation with IPV6={m,n}
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Tom Herbert <tom@herbertland.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Fainelli says:

====================
net: systemport: TX/NAPI improvements

This patch series builds up on Doug's latest changes done in BCMGENET to reduce
the number of spurious interrupts in NAPI, simplify pointer arithmetic and
finally tracking of per TX ring statistics to be SMP friendly.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Similar to c298ede2 ("net: bcmgenet: simplify circular pointer
arithmetic") we don't need to complex arthimetic since we always have a
ring size that is a power of 2.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Do something similar to commit d5810ca3 ("net: bcmgenet: clear
status to reduce spurious interrupts") and clear interrupts right before
servicing them. This reduces the number of interrupts by 10K
interrupts/sec for a TX TCP session 1Gbits/sec.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>