{get,put}_page are atomic operations which we use for page count
handling. The current logic for refcount handling is that we increment
it when passing a skb with the data from the first half of page up to
netstack and recycle the second half of page. This operation protects us
from losing a page since the network stack can decrement the refcount of
page from skb.

The performance can be gently improved by doing the bulk updates of
refcount instead of doing it one by one. During the buffer initialization,
maximize the page's refcount and don't allow the refcount to become
less than two.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Instead of adding a frag and later when dealing with EOP frame accessing
that frag in order to copy the headers onto linear part of skb, we can do
this in ice_add_rx_frag in case where the data_len is still 0 and frame
won't fit onto the linear part as a whole.

Function comment of ice_pull_tail was a bit misleading because of
mentioned optimizations that can be performed (drop a frag/maintaining
accurate truesize of skb) - it seems that this part of logic was dropped
and the comment was not updated to reflect this change.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Introduce ice_can_reuse_rx_page which will verify whether the page can
be reused and return the boolean result to caller.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Introduce ice_get_rx_buf, which will fetch the Rx buffer and do the DMA
synchronization. Length of the packet that hardware Rx descriptor
contains is now read in ice_clean_rx_irq, so we can feed ice_get_rx_buf
with it and resign from rx_desc passed as argument in ice_fetch_rx_buf
and ice_add_rx_frag.
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The hardware now supports link events over the admin receive queue (ARQ),
so enable HW link events over the ARQ and remove code for link event
polling.
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Reviewed-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Someone went through the effort of making this a variable so let's use
it instead of recalculating it again.
Signed-off-by: Alan Brady <alan.brady@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The VLAN rule is lost when VM starts or the AVF driver (iavf.ko) is
reloaded. So it is necessary to add this rule again.
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

When VSI increases the number of queues dynamically, the scheduler
just needs to add the new required nodes rather than re-adjusting with
previously allocated number of nodes. Readjusting didn't provide enough
parents to add the upper layer nodes also can't place lan and rdma
subtrees separately.

In decrease case, keep the VSI configuration with max number of queues
always. This will leave some extra nodes in the tree but no harm done.
Signed-off-by: Victor Raj <victor.raj@intel.com>
Reviewed-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Jiri Pirko says:

====================
devlink: small spring cleanup

Mostly cosmetics and janitor work.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Some drivers are becoming more dependent on NET_DEVLINK being selected
in configuration. With upcoming compat functions, the behavior would be
wrong in case devlink was not compiled in. So make the drivers select
NET_DEVLINK and rely on the functions being there, not just stubs.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add spinlock to protect port type and type_dev pointer consistency.
Without that, userspace may see inconsistent type and type_dev
combinations.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
v1->v2:
- rebased
Signed-off-by: David S. Miller <davem@davemloft.net>

Port needs to be registered first before the type is set. Warn and
bail-out in case it is not.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Move the type set of devlink port after it is registered.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Similar to other driver, move the port type set after netdev registration
is done. Along with that, clear the type before unregistration.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the port attributes are static and cannot change during the port
lifetime, WARN_ON if some driver calls it after registration. Also, no
need to call notifications as it is noop anyway due to check of
devlink_port->registered there.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since attrs are static during the existence of devlink port, set the
before registration of the port.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since attrs are static during the existence of devlink port, set the
before registration of the port.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

__devlink_port_type_set() returns void, it makes no sense to pass it on,
so don't do that.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The netdevice is guaranteed to not disappear so we can rely that
devlink_port and devlink won't disappear as well. No need to take
devlink_mutex so don't take it here.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Call devlink_port_type_eth_set() before devlink_port_register(). Bnxt
instances won't change type during lifetime. This avoids one extra
userspace devlink notification.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Set the attrs properly so delink has enough info to generate physical
port names.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

devlink functions are in use, so include the related header file.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

devlink functions are in use, so include the related header file.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add missing called to mutex_destroy() for two mutexes used
in devlink code.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Igor Russkikh says:

====================
net: aquantia: RX performance optimization patches

Here is a set of patches targeting for performance improvement
on various platforms and protocols.

Our main target was rx performance on iommu systems, notably
NVIDIA Jetson TX2 and NVIDIA Xavier platforms.

We introduce page reuse strategy to better deal with iommu dma mapping costs.
With it we see 80-90% of page reuse under some test configurations on UDP traffic.

This shows good improvements on other systems with IOMMU hardware, like
AMD Ryzen.

We've also improved TCP LRO configuration parameters, allowing packets to better
coalesce.

Page reuse tests were carried out using iperf3, iperf2, netperf and pktgen.
Mainly on UDP traffic, with various packet lengths.

Jetson TX2, UDP, Default MTU:
RX Lost Datagrams
  Before: Max: 69%  Min: 68% Avg: 68.5%
  After:  Max: 41%  Min: 38% Avg: 39.2%
Maximum throughput
  Before: 1.27 Gbits/sec
  After:  2.41 Gbits/sec

AMD Ryzen 5 2400G, UDP, Default MTU:
RX Lost Datagrams
  Before:  Max: 12%  Min: 4.5% Avg: 7.17%
  After:   Max: 6.2% Min: 2.3% Avg: 4.26%
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver is now constantly tested in our lab on aarch64 hardware:
Jetson tx2, Pascal and Xavier tegra based hardware.
Many of tegra smmu related HW bugs were fixed or workarounded already.

Thus, add ARM64 into Kconfig.

Add also COMPILE_TEST dependency.
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Default LRO HW configuration was very conservative.

Low Number of Descriptors per LRO Sequence, small session
timeout, inefficient settings in interrupt generation logic.

Change max number of LRO descriptors from 2 to 16 to
increase performance. Increase maximum coalescing interval
in HW to 250uS. Tune up HW LRO interrupt generation setting
to prevent hw issues with long LRO sessions.
Signed-off-by: Nikita Danilov <nikita.danilov@aquantia.com>
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For multigig rates 1K ring size is often not enough and causes extra
packet drops in hardware.
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This correlates with default internet MTU. This also allows page
flip/reuse to be activated, since each allocated RX page now serves for
two frags/packets.
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before that, we've refilled ring even on single descriptor move.
Under high packet load that caused page allocation logic to be triggered
too often. That made overall ring processing slower.

Moreover, with page buffer reuse implemented, we should give a chance
higher networking levels to process received packets faster, release
the pages they consumed and therefore give a higher chance for these
pages to be reused.

RX ring is now refilled only when AQ_CFG_RX_REFILL_THRES or more
descriptors were processed (32 by default). Under regular traffic this
gives quite enough time for packet to be consumed and page to be reused.
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We introduce internal aq_rxpage wrapper over regular page
where extra field is tracked: rxpage offset inside of allocated page.

This offset allows to reuse one page for multiple packets.
When needed (for example with large frames processing), allocated
pageorder could be customized. This gives even larger page reuse
efficiency.

page_ref_count is used to track page users. If during rx refill
underlying page has users, we increase pg_off by rx frame size
thus the top half of the page is reused.
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Atlantic driver used 14 bytes preallocated skb size. That made L3 protocol
processing inefficient because pskb_pull had to fetch all the L3/L4 headers
from extra fragments.

Specially on UDP flows that caused extra packet drops because CPU was
overloaded with pskb_pull.

This patch uses eth_get_headlen for skb preallocation.
Signed-off-by: Igor Russkikh <igor.russkikh@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-updates-2019-03-20

This series includes updates to mlx5 driver,

1) Compiler warnings cleanup from Saeed Mahameed
2) Parav Pandit simplifies sriov enable/disables
3) Gustavo A. R. Silva, Removes a redundant assignment
4) Moshe Shemesh, Adds Geneve tunnel stateless offload support
5) Eli Britstein, Adds the Support for VLAN modify action and
   Replaces TC VLAN pop and push actions with VLAN modify

Note: This series includes two simple non-mlx5 patches,

1) Declare IANA_VXLAN_UDP_PORT definition in include/net/vxlan.h,
and use it in some drivers.
2) Declare GENEVE_UDP_PORT definition in include/net/geneve.h,
and use it in mlx5 and nfp drivers.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
100GbE Intel Wired LAN Driver Updates 2019-03-22

This series contains updates to ice driver only.

Akeem enables MAC anti-spoofing by default when a new VSI is being
created.  Fixes an issue when reclaiming VF resources back to the pool
after reset, by freeing VF resources separately using the first VF
vector index to traverse the list, instead of starting at the last
assigned vectors list.  Added support for VF & PF promiscuous mode in
the ice driver.  Fixed the PF driver from letting the VF know it is "not
trusted" when it attempts to add more than its permitted additional MAC
addresses.  Altered how the driver gets the VF VSIs instances, instead
of using the mailbox messages to retrieve VSIs, get it directly via the
VF object in the PF data structure.

Bruce fixes return values to resolve static analysis warnings.  Made
whitespace changes to increase readability and reduce code wrapping.

Anirudh cleans up code by removing a function prototype that was never
implemented and removed an unused field in the ice_sched_vsi_info
structure.

Kiran fixes a potential divide by zero issue by adding a check.

Victor cleans up the transmit scheduler by adjusting the stack variable
usage and added/modified debug prints to make them more useful.

Yashaswini updates the driver in VEB mode to ensure that the LAN_EN bit
is set if all the right conditions are met.

Christopher ensures the loopback enable bit is not set for prune switch
rules, since all transmit traffic would be looped back to the internal
switch and dropped.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Eric Dumazet says:

====================
tcp: add rx/tx cache to reduce lock contention

On hosts with many cpus we can observe a very serious contention
on spinlocks used in mm slab layer.

The following can happen quite often :

1) TX path
  sendmsg() allocates one (fclone) skb on CPU A, sends a clone.
  ACK is received on CPU B, and consumes the skb that was in the retransmit
  queue.

2) RX path
  network driver allocates skb on CPU C
  recvmsg() happens on CPU D, freeing the skb after it has been delivered
  to user space.

In both cases, we are hitting the asymetric alloc/free pattern
for which slab has to drain alien caches. At 8 Mpps per second,
this represents 16 Mpps alloc/free per second and has a huge penalty.

In an interesting experiment, I tried to use a single kmem_cache for all the skbs
(in skb_init() : skbuff_fclone_cache = skbuff_head_cache =
                  kmem_cache_create("skbuff_fclone_cache", sizeof(struct sk_buff_fclones),);
qnd most of the contention disappeared, since cpus could better use
their local slab per-cpu cache.

But we can do actually better, in the following patches.

TX : at ACK time, no longer free the skb but put it back in a tcp socket cache,
     so that next sendmsg() can reuse it immediately.

RX : at recvmsg() time, do not free the skb but put it in a tcp socket cache
   so that it can be freed by the cpu feeding the incoming packets in BH.

This increased the performance of small RPC benchmark by about 10 % on a host
with 112 hyperthreads.

v2 : - Solved a race condition : sk_stream_alloc_skb() to make sure the prior
       clone has been freed.
     - Really test rps_needed in sk_eat_skb() as claimed.
     - Fixed rps_needed use in drivers/net/tun.c

v3: Added a #ifdef CONFIG_RPS, to avoid compile error (kbuild robot)
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Often times, recvmsg() system calls and BH handling for a particular
TCP socket are done on different cpus.

This means the incoming skb had to be allocated on a cpu,
but freed on another.

This incurs a high spinlock contention in slab layer for small rpc,
but also a high number of cache line ping pongs for larger packets.

A full size GRO packet might use 45 page fragments, meaning
that up to 45 put_page() can be involved.

More over performing the __kfree_skb() in the recvmsg() context
adds a latency for user applications, and increase probability
of trapping them in backlog processing, since the BH handler
might found the socket owned by the user.

This patch, combined with the prior one increases the rpc
performance by about 10 % on servers with large number of cores.

(tcp_rr workload with 10,000 flows and 112 threads reach 9 Mpps
 instead of 8 Mpps)

This also increases single bulk flow performance on 40Gbit+ links,
since in this case there are often two cpus working in tandem :

 - CPU handling the NIC rx interrupts, feeding the receive queue,
  and (after this patch) freeing the skbs that were consumed.

 - CPU in recvmsg() system call, essentially 100 % busy copying out
  data to user space.

Having at most one skb in a per-socket cache has very little risk
of memory exhaustion, and since it is protected by socket lock,
its management is essentially free.

Note that if rps/rfs is used, we do not enable this feature, because
there is high chance that the same cpu is handling both the recvmsg()
system call and the TCP rx path, but that another cpu did the skb
allocations in the device driver right before the RPS/RFS logic.

To properly handle this case, it seems we would need to record
on which cpu skb was allocated, and use a different channel
to give skbs back to this cpu.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On hosts with a lot of cores, RPC workloads suffer from heavy contention on slab spinlocks.

    20.69%  [kernel]       [k] queued_spin_lock_slowpath
     5.64%  [kernel]       [k] _raw_spin_lock
     3.83%  [kernel]       [k] syscall_return_via_sysret
     3.48%  [kernel]       [k] __entry_text_start
     1.76%  [kernel]       [k] __netif_receive_skb_core
     1.64%  [kernel]       [k] __fget

For each sendmsg(), we allocate one skb, and free it at the time ACK packet comes.

In many cases, ACK packets are handled by another cpus, and this unfortunately
incurs heavy costs for slab layer.

This patch uses an extra pointer in socket structure, so that we try to reuse
the same skb and avoid these expensive costs.

We cache at most one skb per socket so this should be safe as far as
memory pressure is concerned.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We prefer static_branch_unlikely() over static_key_false() these days.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Paolo Abeni says:

====================
net: dev: BYPASS for lockless qdisc

This patch series is aimed at improving xmit performances of lockless qdisc
in the uncontended scenario.

After the lockless refactor pfifo_fast can't leverage the BYPASS optimization.
Due to retpolines the overhead for the avoidables enqueue and dequeue operations
has increased and we see measurable regressions.

The first patch introduces the BYPASS code path for lockless qdisc, and the
second one optimizes such path further. Overall this avoids up to 3 indirect
calls per xmit packet. Detailed performance figures are reported in the 2nd
patch.

 v2 -> v3:
  - qdisc_is_empty() has a const argument (Eric)

 v1 -> v2:
  - use really an 'empty' flag instead of 'not_empty', as
    suggested by Eric
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

With commit c5ad119f ("net: sched: pfifo_fast use skb_array")
pfifo_fast no longer benefit from the TCQ_F_CAN_BYPASS optimization.
Due to retpolines the cost of the enqueue()/dequeue() pair has become
relevant and we observe measurable regression for the uncontended
scenario when the packet-rate is below line rate.

After commit 46b1c18f ("net: sched: put back q.qlen into a
single location") we can check for empty qdisc with a reasonably
fast operation even for nolock qdiscs.

This change extends TCQ_F_CAN_BYPASS support to nolock qdisc.
The new chunk of code mirrors closely the existing one for traditional
qdisc, leveraging a newly introduced helper to read atomically the
qdisc length.

Tested with pktgen in queue xmit mode, with pfifo_fast, a MQ
device, and MQ root qdisc:

threads         vanilla         patched
                kpps            kpps
1               2465            2889
2               4304            5188
4               7898            9589

Same as above, but with a single queue device:

threads         vanilla         patched
                kpps            kpps
1               2556            2827
2               2900            2900
4               5000            5000
8               4700            4700

No mesaurable changes in the contended scenarios, and more 10%
improvement in the uncontended ones.

 v1 -> v2:
  - rebased after flag name change
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: Ivan Vecera <ivecera@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>