platform/kernel/linux-rpi3.git
8 years agoBluetooth: btwilink: Save the packet type before sending
Laura Abbott [Thu, 22 Sep 2016 18:20:42 +0000 (11:20 -0700)]
Bluetooth: btwilink: Save the packet type before sending

Running with KASAN produces some messages:

BUG: KASAN: use-after-free in ti_st_send_frame+0x9c/0x16c at addr
ffffffc064868fe8
Read of size 1 by task kworker/u17:1/1266

<KASAN output trimmed>

Hardware name: HiKey Development Board (DT)
Workqueue: hci0 hci_cmd_work
Call trace:
[<ffffffc00008c00c>] dump_backtrace+0x0/0x178
[<ffffffc00008c1a4>] show_stack+0x20/0x28
[<ffffffc00067da38>] dump_stack+0xa8/0xe0
[<ffffffc000288430>] print_trailer+0x110/0x174
[<ffffffc00028aedc>] object_err+0x4c/0x5c
[<ffffffc00028f714>] kasan_report_error+0x254/0x54c
[<ffffffc00028fa70>] kasan_report+0x64/0x70
[<ffffffc00028eb8c>] __asan_load1+0x4c/0x54
[<ffffffc000b59b24>] ti_st_send_frame+0x9c/0x16c
[<ffffffc000ee8dcc>] hci_send_frame+0xb4/0x118
[<ffffffc000ee8efc>] hci_cmd_work+0xcc/0x154
[<ffffffc0000f6c48>] process_one_work+0x26c/0x7a4
[<ffffffc0000f721c>] worker_thread+0x9c/0x73c
[<ffffffc000100250>] kthread+0x138/0x154
[<ffffffc000085c50>] ret_from_fork+0x10/0x40

The packet is being accessed for statistics after it has been freed.
Save the packet type before sending for statistics afterwards.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
8 years agoBluetooth: Fix not updating scan rsp when adv off
Michał Narajowski [Thu, 22 Sep 2016 14:01:39 +0000 (16:01 +0200)]
Bluetooth: Fix not updating scan rsp when adv off

Scan response data should not be updated unless there
is an advertising instance.

Signed-off-by: Michał Narajowski <michal.narajowski@codecoup.pl>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
8 years agoBluetooth: Add a new 04ca:3011 QCA_ROME device
Dmitry Tunin [Wed, 21 Sep 2016 16:13:08 +0000 (19:13 +0300)]
Bluetooth: Add a new 04ca:3011 QCA_ROME device

BugLink: https://bugs.launchpad.net/bugs/1535802
T:  Bus=01 Lev=02 Prnt=02 Port=04 Cnt=01 Dev#=  3 Spd=12  MxCh= 0
D:  Ver= 1.10 Cls=e0(wlcon) Sub=01 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=04ca ProdID=3011 Rev=00.01
C:  #Ifs= 2 Cfg#= 1 Atr=e0 MxPwr=100mA
I:  If#= 0 Alt= 0 #EPs= 3 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb
I:  If#= 1 Alt= 0 #EPs= 2 Cls=e0(wlcon) Sub=01 Prot=01 Driver=btusb

Signed-off-by: Dmitry Tunin <hanipouspilot@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
8 years agoBluetooth: Fix NULL pointer dereference in mgmt context
Arek Lichwa [Thu, 22 Sep 2016 12:08:05 +0000 (14:08 +0200)]
Bluetooth: Fix NULL pointer dereference in mgmt context

Adds missing callback assignment to cmd_complete in pending management command
context. Dump path involves security procedure performed on legacy (pre-SSP)
devices with service security requirements set to HIGH (16digits PIN).
It fails when shorter PIN is delivered by user.

[    1.517950] Bluetooth: PIN code is not 16 bytes long
[    1.518491] BUG: unable to handle kernel NULL pointer dereference at           (null)
[    1.518584] IP: [<          (null)>]           (null)
[    1.518584] PGD 9e08067 PUD 9fdf067 PMD 0
[    1.518584] Oops: 0010 [#1] SMP
[    1.518584] Modules linked in:
[    1.518584] CPU: 0 PID: 1002 Comm: kworker/u3:2 Not tainted 4.8.0-rc6-354649-gaf4168c #16
[    1.518584] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.9.3-20160701_074356-anatol 04/01/2014
[    1.518584] Workqueue: hci0 hci_rx_work
[    1.518584] task: ffff880009ce14c0 task.stack: ffff880009e10000
[    1.518584] RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
[    1.518584] RSP: 0018:ffff880009e13bc8  EFLAGS: 00010293
[    1.518584] RAX: 0000000000000000 RBX: ffff880009eed100 RCX: 0000000000000006
[    1.518584] RDX: ffff880009ddc000 RSI: 0000000000000000 RDI: ffff880009eed100
[    1.518584] RBP: ffff880009e13be0 R08: 0000000000000000 R09: 0000000000000001
[    1.518584] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[    1.518584] R13: ffff880009e13ccd R14: ffff880009ddc000 R15: ffff880009ddc010
[    1.518584] FS:  0000000000000000(0000) GS:ffff88000bc00000(0000) knlGS:0000000000000000
[    1.518584] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.518584] CR2: 0000000000000000 CR3: 0000000009fdd000 CR4: 00000000000006f0
[    1.518584] Stack:
[    1.518584]  ffffffff81909808 ffff880009e13cce ffff880009e0d40b ffff880009e13c68
[    1.518584]  ffffffff818f428d 00000000024000c0 ffff880009e13c08 ffffffff810ca903
[    1.518584]  ffff880009e13c48 ffffffff811ade34 ffffffff8178c31f ffff880009ee6200
[    1.518584] Call Trace:
[    1.518584]  [<ffffffff81909808>] ? mgmt_pin_code_neg_reply_complete+0x38/0x60
[    1.518584]  [<ffffffff818f428d>] hci_cmd_complete_evt+0x69d/0x3200
[    1.518584]  [<ffffffff810ca903>] ? rcu_read_lock_sched_held+0x53/0x60
[    1.518584]  [<ffffffff811ade34>] ? kmem_cache_alloc+0x1a4/0x200
[    1.518584]  [<ffffffff8178c31f>] ? skb_clone+0x4f/0xa0
[    1.518584]  [<ffffffff818f9d81>] hci_event_packet+0x8e1/0x28e0
[    1.518584]  [<ffffffff81a421f1>] ? _raw_spin_unlock_irqrestore+0x31/0x50
[    1.518584]  [<ffffffff810aea3e>] ? trace_hardirqs_on_caller+0xee/0x1b0
[    1.518584]  [<ffffffff818e6bd1>] hci_rx_work+0x1e1/0x5b0
[    1.518584]  [<ffffffff8107e4bd>] ? process_one_work+0x1ed/0x6b0
[    1.518584]  [<ffffffff8107e538>] process_one_work+0x268/0x6b0
[    1.518584]  [<ffffffff8107e4bd>] ? process_one_work+0x1ed/0x6b0
[    1.518584]  [<ffffffff8107e9c3>] worker_thread+0x43/0x4e0
[    1.518584]  [<ffffffff8107e980>] ? process_one_work+0x6b0/0x6b0
[    1.518584]  [<ffffffff8107e980>] ? process_one_work+0x6b0/0x6b0
[    1.518584]  [<ffffffff8108505f>] kthread+0xdf/0x100
[    1.518584]  [<ffffffff81a4297f>] ret_from_fork+0x1f/0x40
[    1.518584]  [<ffffffff81084f80>] ? kthread_create_on_node+0x210/0x210

Signed-off-by: Arek Lichwa <arek.lichwa@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
8 years agoMerge branch 'ftgmac100-ast2500-support'
David S. Miller [Thu, 22 Sep 2016 07:31:22 +0000 (03:31 -0400)]
Merge branch 'ftgmac100-ast2500-support'

Joel Stanley says:

====================
ftgmac100 support for ast2500

This series adds support to the ftgmac100 driver for the Aspeed ast2400 and
ast2500 SoCs. In particular, they ensure the driver works correctly on the
ast2500 where the MAC block has seen some changes in register layout.

They have been tested on ast2400 and ast2500 systems with the NCSI stack and
with a directly attached PHY.

V2 reworks the two patches relating to PHYSTS_CHG into the one patch that
disables the interrupt instead of playing with interrupt sensitivity. I kept
patch 4 'net/faraday: Clear stale interrupts' which was first introduced to
clear the stale PHYSTS_CHG interrupt, as it helps keep us safe from unhygienic
(vendor) bootloaders.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/faraday: Mask out PHYSTS_CHG interrupt
Joel Stanley [Wed, 21 Sep 2016 23:05:03 +0000 (08:35 +0930)]
net/faraday: Mask out PHYSTS_CHG interrupt

The PHYSTS_CHG (the ftgmac100's PHY IRQ) is telling the system to go
look at the PHY registers for a link status change.

The interrupt was causing issues on Aspeed SoC where some board designs
had an active high configuration, some active low, and in some cases
repurposed for other functions. When misconfigured Linux would chew 100%
of CPU cycles servicing interrupts:

 [   20.280000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG
 [   20.280000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG
 [   20.280000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG
 [   20.300000] ftgmac100 1e660000.ethernet eth0: [ISR] = 0x200: PHYSTS_CHG

While in the ftgmac100 IP can be configured for high, low and edge
sensitivity the current driver always polls the PHY, so we chose to mask
out the interrupt.

See https://patchwork.ozlabs.org/patch/672099/ for more discussion.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/faraday: Configure old MDIO interface on Aspeed SoCs
Joel Stanley [Wed, 21 Sep 2016 23:05:02 +0000 (08:35 +0930)]
net/faraday: Configure old MDIO interface on Aspeed SoCs

The Aspeed SoCs have a new MDIO interface as an option in the G4 and G5
SoCs. The old one is still available, so select it in order to remain
compatible with the ftgmac100 driver.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/faraday: Clear stale interrupts
Gavin Shan [Wed, 21 Sep 2016 23:05:01 +0000 (08:35 +0930)]
net/faraday: Clear stale interrupts

There is stale interrupt (PHYSTS_CHG in ISR, bit#6 in 0x0) from
the bootloader (uboot) when enabling the MAC. The stale interrupts
aren't part of kernel and should be cleared.

This clears the stale interrupts in ISR (0x0) when enabling the MAC.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/faraday: Adapt for Aspeed SoCs
Joel Stanley [Wed, 21 Sep 2016 23:05:00 +0000 (08:35 +0930)]
net/faraday: Adapt for Aspeed SoCs

The RXDES and TXDES registers bits in the ftgmac100 indicates EDO{R,T}R
at bit position 15 for the Faraday Tech IP. However, the version of this
IP present in the Aspeed SoCs has these bits at position 30 in the
registers.

It appers that ast2400 SoCs support both positions, with the 15th bit
marked as reserved but still functional. In the ast2500 this bit is
reused for another function, so we need a work around.

This was confirmed with engineers from Aspeed that using bit 30 is
correct for both the ast2400 and ast2500 SoCs.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/faraday: Make EDO{R,T}R bits configurable
Andrew Jeffery [Wed, 21 Sep 2016 23:04:59 +0000 (08:34 +0930)]
net/faraday: Make EDO{R,T}R bits configurable

These bits are #defined at a fixed location. In order to support future
hardware that has chosen to move these bits around move the bits into a
member of the struct ftgmac100.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/faraday: Separate rx page storage from rxdesc
Andrew Jeffery [Wed, 21 Sep 2016 23:04:58 +0000 (08:34 +0930)]
net/faraday: Separate rx page storage from rxdesc

The ftgmac100 hardware revision in e.g. the Aspeed AST2500 no longer
reserves all bits in RXDES#2 but instead uses the bottom 16 bits to
store MAC frame metadata. Avoid corruption by shifting struct page
pointers out to their own member in struct ftgmac100.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agocxgb4: Convert to use simple_open()
Wei Yongjun [Wed, 21 Sep 2016 15:09:16 +0000 (15:09 +0000)]
cxgb4: Convert to use simple_open()

Remove an open coded simple_open() function and replace file
operations references to the function with simple_open()
instead.

Generated by: scripts/coccinelle/api/simple_open.cocci

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: dsa: qca8k: use mdio_module_driver to simplify the code
Wei Yongjun [Wed, 21 Sep 2016 15:05:05 +0000 (15:05 +0000)]
net: dsa: qca8k: use mdio_module_driver to simplify the code

mdio_module_driver() makes the code simpler by eliminating
boilerplate code.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: dsa: qca8k: fix non static symbol warning
Wei Yongjun [Wed, 21 Sep 2016 15:04:43 +0000 (15:04 +0000)]
net: dsa: qca8k: fix non static symbol warning

Fixes the following sparse warning:

drivers/net/dsa/qca8k.c:259:22: warning:
 symbol 'qca8k_regmap_config' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'sctp-align'
David S. Miller [Thu, 22 Sep 2016 07:13:39 +0000 (03:13 -0400)]
Merge branch 'sctp-align'

Marcelo Ricardo Leitner says:

====================
Rename WORD_TRUNC/ROUND macros and use them

This patchset aims to rename these macros to a non-confusing name, as
reported by David Laight and David Miller, and to update all remaining
places to make use of it, which was 1 last remaining spot.

v3:
- Name it SCTP_PAD4 instead of SCTP_ALIGN4, as suggested by David Laight
v2:
- fixed 2nd patch summary

Details on the specific changelogs.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agosctp: make use of SCTP_TRUNC4 macro
Marcelo Ricardo Leitner [Wed, 21 Sep 2016 11:45:56 +0000 (08:45 -0300)]
sctp: make use of SCTP_TRUNC4 macro

And avoid the usage of '&~3'. This is the last place still not using
the macro.
Also break the line to make it easier to read.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agosctp: rename WORD_TRUNC/ROUND macros
Marcelo Ricardo Leitner [Wed, 21 Sep 2016 11:45:55 +0000 (08:45 -0300)]
sctp: rename WORD_TRUNC/ROUND macros

To something more meaningful these days, specially because this is
working on packet headers or lengths and which are not tied to any CPU
arch but to the protocol itself.

So, WORD_TRUNC becomes SCTP_TRUNC4 and WORD_ROUND becomes SCTP_PAD4.

Reported-by: David Laight <David.Laight@ACULAB.COM>
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'mlx5e-xdp'
David S. Miller [Thu, 22 Sep 2016 06:51:48 +0000 (02:51 -0400)]
Merge branch 'mlx5e-xdp'

Tariq Toukan says:

====================
mlx5e XDP support

This series adds XDP support in mlx5e driver.
This includes the use cases: XDP_DROP, XDP_PASS, and XDP_TX.

Single stream performance tests show 16.5 Mpps for XDP_DROP,
and 12.4 Mpps for XDP_TX, with nice scalability for multiple streams/rings.

This rate of XDP_DROP is lower than the 32 Mpps we got in previous
implementation, when Striding RQ was used.

We moved to non-Striding RQ, as some XDP_TX requirements (like headroom,
packet-per-page) cannot be satisfied with the current Striding RQ HW,
and we decided to fully support both DROP/TX.

Few directions are considered in order to enable the faster rate for XDP_DROP,
e.g a possibility for users to enable Striding RQ so they choose optimized
XDP_DROP on the price of partial XDP_TX functionality, or some HW changes.

Series generated against net-next commit:
cf714ac147e0 'ipvlan: Fix dependency issue'

Thanks,
Tariq

V2:
* patch 8:
 - when XDP_TX fails, call mlx5e_page_release and drop the packet.
 - update xdp_tx counter within mlx5e_xmit_xdp_frame.
   (mlx5e_xmit_xdp_frame return value becomes obsolete, change it to void)
 - drop the packet for unknown XDP return code.
* patch 9:
 - use a boolean for xdp_doorbell in SQ struct, instead of dragging it
   throughout the functions calls.
 - handle doorbell and counters within mlx5e_xmit_xdp_frame.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: XDP TX xmit more
Saeed Mahameed [Wed, 21 Sep 2016 09:19:49 +0000 (12:19 +0300)]
net/mlx5e: XDP TX xmit more

Previously we rang XDP SQ doorbell on every forwarded XDP packet.

Here we introduce a xmit more like mechanism that will queue up more
than one packet into SQ (up to RX napi budget) w/o notifying the hardware.

Once RX napi budget is consumed and we exit napi RX loop, we will
flush (doorbell) all XDP looped packets in case there are such.

XDP forward packet rate:

Comparing XDP with and w/o xmit more (bulk transmit):

RX Cores    XDP TX       XDP TX (xmit more)
---------------------------------------------------
1           6.5Mpps      12.4Mpps
2          13.2Mpps      24.2Mpps
4          25.2Mpps      36.3Mpps*
8          36.3Mpps*     36.3Mpps*

*My xmitter was limited to 36.3Mpps, so it is the bottleneck.
It seems that receive side can handle more.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: XDP TX forwarding support
Saeed Mahameed [Wed, 21 Sep 2016 09:19:48 +0000 (12:19 +0300)]
net/mlx5e: XDP TX forwarding support

Adding support for XDP_TX forwarding from xdp program.
Using XDP, now user can loop packets out of the same port.

We create a dedicated TX SQ for each channel that will serve
XDP programs that return XDP_TX action to loop packets back to
the wire directly from the channel RQ RX path.

For that RX pages will now need to be mapped bi-directionally,
and on XDP_TX action we will sync the page back to device then
queue it into SQ for transmission.  The XDP xmit frame function will
report back to the RX path if the page was consumed (transmitted), if so,
RX path will forget about that page as if it were released to the stack.
Later on, on XDP TX completion, the page will be released back to the
page cache.

For simplicity this patch will hit a doorbell on every XDP TX packet.

Next patch will introduce a xmit more like mechanism that will
queue up more than one packet into SQ w/o notifying the hardware,
once RX napi loop is done we will hit doorbell once for all XDP TX
packets form the previous loop.  This should drastically improve
XDP TX performance.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: Have a clear separation between different SQ types
Saeed Mahameed [Wed, 21 Sep 2016 09:19:47 +0000 (12:19 +0300)]
net/mlx5e: Have a clear separation between different SQ types

Make a clear separate between Regular SQ (TXQ) and ICO SQ creation,
destruction and union their mutual information structures.

Don't allocate redundant TXQ skb/wqe_info/dma_fifo arrays for ICO SQ.
And have a different SQ edge for ICO SQ than TXQ SQ, to be more
accurate.

In preparation for XDP TX support.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: XDP fast RX drop bpf programs support
Rana Shahout [Wed, 21 Sep 2016 09:19:46 +0000 (12:19 +0300)]
net/mlx5e: XDP fast RX drop bpf programs support

Add support for the BPF_PROG_TYPE_PHYS_DEV hook in mlx5e driver.

When XDP is on we make sure to change channels RQs type to
MLX5_WQ_TYPE_LINKED_LIST rather than "striding RQ" type to
ensure "page per packet".

On XDP set, we fail if HW LRO is set and request from user to turn it
off.  Since on ConnectX4-LX HW LRO is always on by default, this will be
annoying, but we prefer not to enforce LRO off from XDP set function.

Full channels reset (close/open) is required only when setting XDP
on/off.

When XDP set is called just to exchange programs, we will update
each RQ xdp program on the fly and for synchronization with current
data path RX activity of that RQ, we temporally disable that RQ and
ensure RX path is not running, quickly update and re-enable that RQ,
for that we do:
- rq.state = disabled
- napi_synnchronize
- xchg(rq->xdp_prg)
- rq.state = enabled
- napi_schedule // Just in case we've missed an IRQ

Packet rate performance testing was done with pktgen 64B packets and on
TX side and, TC drop action on RX side compared to XDP fast drop.

CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz

Comparison is done between:
1. Baseline, Before this patch with TC drop action
2. This patch with TC drop action
3. This patch with XDP RX fast drop

RX Cores  Baseline(TC drop)    TC drop    XDP fast Drop
--------------------------------------------------------------
1            5.3Mpps           5.3Mpps     16.5Mpps
2           10.2Mpps          10.2Mpps     31.3Mpps
4           20.5Mpps          19.9Mpps     36.3Mpps*

*My xmitter was limited to 36.3Mpps, so it is the bottleneck.
It seems that receive side can handle more.

Signed-off-by: Rana Shahout <ranas@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: Dynamic RQ type infrastructure
Saeed Mahameed [Wed, 21 Sep 2016 09:19:45 +0000 (12:19 +0300)]
net/mlx5e: Dynamic RQ type infrastructure

Add two helper functions to allow dynamic changes of RQ type.

mlx5e_set_rq_priv_params and mlx5e_set_rq_type_params will be
used on netdev creation to determine the default RQ type.

This will be needed later for downstream patches of XDP support.
When enabling XDP we will dynamically move from striding RQ to
linked list RQ type.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: Slightly reduce hardware LRO size
Saeed Mahameed [Wed, 21 Sep 2016 09:19:44 +0000 (12:19 +0300)]
net/mlx5e: Slightly reduce hardware LRO size

Before this patch LRO size was 64K, now with build_skb requires
extra room, headroom + sizeof(skb_shared_info) added to the data
buffer will make  wqe size or page_frag_size slightly larger than
64K which will demand order 5 page instead of order 4 in 4K page systems.

We take those extra bytes from hardware LRO data size in order to not
increase the required page order for when hardware LRO is enabled.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: Union RQ RX info per RQ type
Saeed Mahameed [Wed, 21 Sep 2016 09:19:43 +0000 (12:19 +0300)]
net/mlx5e: Union RQ RX info per RQ type

We have two types of RX RQs, and they use two separate sets of
info arrays and structures in RX data path function.  Today those
structures are mutually exclusive per RQ type, hence one kind is
allocated on RQ creation according to the RQ type.

For better cache locality and to minimalize the
sizeof(struct mlx5e_rq), in this patch we define them as a union.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx5e: Build RX SKB on demand
Saeed Mahameed [Wed, 21 Sep 2016 09:19:42 +0000 (12:19 +0300)]
net/mlx5e: Build RX SKB on demand

For non-striding RQ configuration before this patch we had a ring
with pre-allocated SKBs and mapped the SKB->data buffers for
device.

For robustness and better RX data buffers management, we allocate a
page per packet and build_skb around it.

This patch (which is a prerequisite for XDP) will actually reduce
performance for normal stack usage, because we are now hitting a bottleneck
in the page allocator. We use the page-cache to restore or even improve
performance in comparison to the old RX scheme.

Packet rate performance testing was done with pktgen 64B packets on xmit
side and TC ingress dropping action on RX side.

CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz

Comparison is done between:
 1.Baseline, before 'net/mlx5e: Build RX SKB on demand'
 2.Build SKB with RX page cache (This patch)

RX Cores  Baseline    Build SKB+page-cache    Improvement
-----------------------------------------------------------
1          4.16Mpps       5.33Mpps                28%
2          7.16Mpps      10.24Mpps                43%
4         13.61Mpps      20.51Mpps                51%
8         25.32Mpps      32.00Mpps                26%

All respective cores were 100% utilized.

Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: implement TSQ for retransmits
Eric Dumazet [Wed, 21 Sep 2016 05:45:58 +0000 (22:45 -0700)]
tcp: implement TSQ for retransmits

We saw sch_fq drops caused by the per flow limit of 100 packets and TCP
when dealing with large cwnd and bursts of retransmits.

Even after increasing the limit to 1000, and even after commit
10d3be569243 ("tcp-tso: do not split TSO packets at retransmit time"),
we can still have these drops.

Under certain conditions, TCP can spend a considerable amount of
time queuing thousands of skbs in a single tcp_xmit_retransmit_queue()
invocation, incurring latency spikes and stalls of other softirq
handlers.

This patch implements TSQ for retransmits, limiting number of packets
and giving more chance for scheduling packets in both ways.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'mv88e6390-prep'
David S. Miller [Thu, 22 Sep 2016 06:20:16 +0000 (02:20 -0400)]
Merge branch 'mv88e6390-prep'

Andrew Lunn says:

====================
Preparation for mv88e6390

These two patches are a couple of preparation steps for supporting the
the MV88E6390 family of chips. This is a new generation from Marvell,
and will need more feature flags than are currently available in an
unsigned long. Expand to an unsigned long long. The MV88E6390 also
places its port registers somewhere else, so add a wrapper around port
register access.

v2:
 Rework wrappers to use mv88e6xxx_{read|write}
 Simpliy some (err < ) to (err)
Add Reviewed by tag.

v3::
 reg = reg & foo -> reg &= foo
 Fix over zealous s/ret/err
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: dsa: mv88e6xxx: Convert flag bits to unsigned long long
Andrew Lunn [Tue, 20 Sep 2016 23:40:32 +0000 (01:40 +0200)]
net: dsa: mv88e6xxx: Convert flag bits to unsigned long long

We are soon going to run out of flag bits on 32bit systems. Convert to
unsigned long long.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: dsa: mv88e6xxx: Add helper for accessing port registers
Andrew Lunn [Tue, 20 Sep 2016 23:40:31 +0000 (01:40 +0200)]
net: dsa: mv88e6xxx: Add helper for accessing port registers

There is a device coming soon which places its port registers
somewhere different to all other Marvell switches supported so far.
Add helper functions for reading/writing port registers, making it
easier to handle this new device.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoptp_clock: future-proofing drivers against PTP subsystem becoming optional
Nicolas Pitre [Tue, 20 Sep 2016 23:25:58 +0000 (19:25 -0400)]
ptp_clock: future-proofing drivers against PTP subsystem becoming optional

Drivers must be ready to accept NULL from ptp_clock_register() if the
PTP clock subsystem is configured out.

This patch documents that and ensures that all drivers cope well
with a NULL return.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Eugenia Emantayev <eugenia@mellanox.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: ethernet: hisilicon: hns: use new api ethtool_{get|set}_link_ksettings
Philippe Reynes [Tue, 20 Sep 2016 20:30:12 +0000 (22:30 +0200)]
net: ethernet: hisilicon: hns: use new api ethtool_{get|set}_link_ksettings

The ethtool api {get|set}_settings is deprecated.
We move this driver to new api {get|set}_link_ksettings.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: ethernet: hisilicon: hns: use phydev from struct net_device
Philippe Reynes [Tue, 20 Sep 2016 20:30:11 +0000 (22:30 +0200)]
net: ethernet: hisilicon: hns: use phydev from struct net_device

The private structure contain a pointer to phydev, but the structure
net_device already contain such pointer. So we can remove the pointer
phydev in the private structure, and update the driver to use the
one contained in struct net_device.

Signed-off-by: Philippe Reynes <tremyfr@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: ethernet: mediatek: fix missing changes merged for conflicts overlapping commits
Sean Wang [Tue, 20 Sep 2016 15:53:24 +0000 (23:53 +0800)]
net: ethernet: mediatek: fix missing changes merged for conflicts overlapping commits

add the missing commits about
1)
Commit d3bd1ce4db8e843dce421e2f8f123e5251a9c7d3
("remove redundant free_irq for devm_request_ir allocated irq")
2)
Commit 7c6b0d76fa02213393815e3b6d5e4a415bf3f0e2
("fix logic unbalance between probe and remove")

during merge for conflicts overlapping commits by
Commit b20b378d49926b82c0a131492fa8842156e0e8a9
("Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net")

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'cxgb4-tc-offload'
David S. Miller [Thu, 22 Sep 2016 05:40:07 +0000 (01:40 -0400)]
Merge branch 'cxgb4-tc-offload'

Rahul Lakkireddy says:

====================
cxgb4: add support for offloading TC u32 filters

This series of patches add support to offload TC u32 filters onto
Chelsio NICs.

Patch 1 moves current common filter code to separate files
in order to provide a common api for performing packet classification
and filtering in Chelsio NICs.

Patch 2 enables filters for normal NIC configuration and implements
common api for setting and deleting filters.

Patches 3-5 add support for TC u32 offload via ndo_setup_tc.

---
v3:

Based on review and suggestion from David Miller <davem@davemloft.net>
- Fixed all local variable declarations by placing them in longest line
  first and shortest line last order.

v2:

Based on review and suggestions from Jiri Pirko <jiri@resnulli.us>:
- Replaced macros S and U with appropriate static helper functions.
- Moved completion code for set and delete filters to respective
  functions cxgb4_set_filter() and cxgb4_del_filter().  Renamed the
  original functions to __cxgb4_set_filter() and __cxgb4_del_filter()
  in case synchronization is not required.
- Dropped debugfs patch.
- Merged code for inserting and deleting u32 filters into a single
  patch.
- Reworked and fixed bugs with traversing the actions list.
- Removed all unnecessary extra ().
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agocxgb4: add support for drop and redirect actions
Rahul Lakkireddy [Tue, 20 Sep 2016 11:43:10 +0000 (17:13 +0530)]
cxgb4: add support for drop and redirect actions

Add support for dropping matched packets in hardware.  Also add support
for re-directing matched packets to a specified port in hardware.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agocxgb4: add support for offloading u32 filters
Rahul Lakkireddy [Tue, 20 Sep 2016 11:43:09 +0000 (17:13 +0530)]
cxgb4: add support for offloading u32 filters

Add support for offloading u32 filter onto hardware.  Links are stored
in a jump table to perform necessary jumps to match TCP/UDP header.
When inserting rules in the linked bucket, the TCP/UDP match fields
in the corresponding entry of the jump table are appended to the filter
rule before insertion.  If a link is deleted, then all corresponding
filters associated with the link are also deleted.  Also enable
hardware tc offload as a supported feature.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agocxgb4: add parser to translate u32 filters to internal spec
Rahul Lakkireddy [Tue, 20 Sep 2016 11:43:08 +0000 (17:13 +0530)]
cxgb4: add parser to translate u32 filters to internal spec

Parse information sent by u32 into internal filter specification.
Add support for parsing several fields in IPv4, IPv6, TCP, and UDP.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agocxgb4: add common api support for configuring filters
Rahul Lakkireddy [Tue, 20 Sep 2016 11:43:07 +0000 (17:13 +0530)]
cxgb4: add common api support for configuring filters

Enable filters for non-offload configuration and add common api support
for setting and deleting filters in LE-TCAM region of the hardware.

IPv4 filters occupy one slot.  IPv6 filters occupy 4 slots and must
be on a 4-slot boundary.  IPv4 filters can not occupy a slot belonging
to IPv6 and the vice-versa is also true.

Filters are set and deleted asynchronously.  Use completion to wait
for reply from firmware in order to allow for synchronization if needed.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agocxgb4: move common filter code to separate file
Rahul Lakkireddy [Tue, 20 Sep 2016 11:43:06 +0000 (17:13 +0530)]
cxgb4: move common filter code to separate file

Move common filter code to separate files.  Also fix the following
checkpatch checks.

CHECK: Comparison to NULL could be written "!f->l2t"
+               if (f->l2t == NULL) {

CHECK: spaces preferred around that '/' (ctx:VxV)
+       fwr->len16_pkd = htonl(FW_WR_LEN16_V(sizeof(*fwr)/16));

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: skbuff: Coding: Use eth_type_vlan() instead of open coding it
Shmulik Ladkani [Tue, 20 Sep 2016 09:48:37 +0000 (12:48 +0300)]
net: skbuff: Coding: Use eth_type_vlan() instead of open coding it

Fix 'skb_vlan_pop' to use eth_type_vlan instead of directly comparing
skb->protocol to ETH_P_8021Q or ETH_P_8021AD.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Reviewed-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: skbuff: Remove errornous length validation in skb_vlan_pop()
Shmulik Ladkani [Tue, 20 Sep 2016 09:48:36 +0000 (12:48 +0300)]
net: skbuff: Remove errornous length validation in skb_vlan_pop()

In 93515d53b1
  "net: move vlan pop/push functions into common code"
skb_vlan_pop was moved from its private location in openvswitch to
skbuff common code.

In case skb has non hw-accel vlan tag, the original 'pop_vlan()' assured
that skb->len is sufficient (if skb->len < VLAN_ETH_HLEN then pop was
considered a no-op).

This validation was moved as is into the new common 'skb_vlan_pop'.

Alas, in its original location (openvswitch), there was a guarantee that
'data' points to the mac_header, therefore the 'skb->len < VLAN_ETH_HLEN'
condition made sense.
However there's no such guarantee in the generic 'skb_vlan_pop'.

For short packets received in rx path going through 'skb_vlan_pop',
this causes 'skb_vlan_pop' to fail pop-ing a valid vlan hdr (in the non
hw-accel case) or to fail moving next tag into hw-accel tag.

Remove the 'skb->len < VLAN_ETH_HLEN' condition entirely:
It is superfluous since inner '__skb_vlan_pop' already verifies there
are VLAN_ETH_HLEN writable bytes at the mac_header.

Note this presents a slight change to skb_vlan_pop() users:
In case total length is smaller than VLAN_ETH_HLEN, skb_vlan_pop() now
returns an error, as opposed to previous "no-op" behavior.
Existing callers (e.g. tc act vlan, ovs) usually drop the packet if
'skb_vlan_pop' fails.

Fixes: 93515d53b1 ("net: move vlan pop/push functions into common code")
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Cc: Pravin Shelar <pshelar@ovn.org>
Reviewed-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'vlan_act_modify'
David S. Miller [Thu, 22 Sep 2016 05:34:26 +0000 (01:34 -0400)]
Merge branch 'vlan_act_modify'

Shmulik Ladkani says:

====================
act_vlan: Introduce TCA_VLAN_ACT_MODIFY vlan action

TCA_VLAN_ACT_MODIFY allows one to change an existing tag.

It accepts same attributes as TCA_VLAN_ACT_PUSH (protocol, id,
priority).
If packet is vlan tagged, then the tag gets overwritten according to
user specified attributes.

For example, this allows user to replace a tag's vid while preserving
its priority bits (as opposed to "action vlan pop pipe action vlan push").
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/sched: act_vlan: Introduce TCA_VLAN_ACT_MODIFY vlan action
Shmulik Ladkani [Mon, 19 Sep 2016 16:11:10 +0000 (19:11 +0300)]
net/sched: act_vlan: Introduce TCA_VLAN_ACT_MODIFY vlan action

TCA_VLAN_ACT_MODIFY allows one to change an existing tag.

It accepts same attributes as TCA_VLAN_ACT_PUSH (protocol, id,
priority).
If packet is vlan tagged, then the tag gets overwritten according to
user specified attributes.

For example, this allows user to replace a tag's vid while preserving
its priority bits (as opposed to "action vlan pop pipe action vlan push").

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: skbuff: Export __skb_vlan_pop
Shmulik Ladkani [Mon, 19 Sep 2016 16:11:09 +0000 (19:11 +0300)]
net: skbuff: Export __skb_vlan_pop

This exports the functionality of extracting the tag from the payload,
without moving next vlan tag into hw accel tag.

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'mlx4-next'
David S. Miller [Thu, 22 Sep 2016 01:52:51 +0000 (21:52 -0400)]
Merge branch 'mlx4-next'

Tariq Toukan says:

====================
mlx4 misc cleanups and improvements

This patchset contains some cleanups and improvements from the team
to the mlx4 Eth and core drivers.

Series generated against net-next commit:
5a7a5555a362 'net sched: stylistic cleanups'
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx4_core: Fix deadlock when switching between polling and event fw commands
Jack Morgenstein [Tue, 20 Sep 2016 11:39:42 +0000 (14:39 +0300)]
net/mlx4_core: Fix deadlock when switching between polling and event fw commands

When switching from polling-based fw commands to event-based fw
commands, there is a race condition which could cause a fw command
in another task to hang: that task will keep waiting for the polling
sempahore, but may never be able to acquire it. This is due to
mlx4_cmd_use_events, which "down"s the sempahore back to 0.

During driver initialization, this is not a problem, since no other
tasks which invoke FW commands are active.

However, there is a problem if the driver switches to polling mode
and then back to event mode during normal operation.

The "test_interrupts" feature does exactly that.
Running "ethtool -t <eth device> offline" causes the PF driver to
temporarily switch to polling mode, and then back to event mode.
(Note that for VF drivers, such switching is not performed).

Fix this by adding a read-write semaphore for protection when
switching between modes.

Fixes: 225c7b1feef1 ("IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx4_core: Use RCU to perform radix tree lookup for SRQ
Leon Romanovsky [Tue, 20 Sep 2016 11:39:41 +0000 (14:39 +0300)]
net/mlx4_core: Use RCU to perform radix tree lookup for SRQ

Radix tree lookup can be performed without locking.

Fixes: 225c7b1feef1 ("IB/mlx4: Add a driver Mellanox ConnectX InfiniBand adapters")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Suggested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx4_en: Fix wrong indentation
Kamal Heib [Tue, 20 Sep 2016 11:39:40 +0000 (14:39 +0300)]
net/mlx4_en: Fix wrong indentation

Use tabs instead of spaces before if statement, no functional change.

Fixes: e7c1c2c46201 ("mlx4_en: Added self diagnostics test implementation")
Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet/mlx4_en: Add branch prediction hints in RX data-path
Tariq Toukan [Tue, 20 Sep 2016 11:39:39 +0000 (14:39 +0300)]
net/mlx4_en: Add branch prediction hints in RX data-path

Add likely/unlikely hints to improve branch predictions
in the RX data-path.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'bpf-hw-offload'
David S. Miller [Wed, 21 Sep 2016 23:50:15 +0000 (19:50 -0400)]
Merge branch 'bpf-hw-offload'

Jakub Kicinski says:

====================
BPF hardware offload (cls_bpf for now)

Rebased and improved.

v7:
 - fix patch 4.
v6 (patch 8 only):
 - explicitly check for registers >= MAX_BPF_REG;
 - fix leaky error path.
v5:
 - fix names of guard defines in bpf_verfier.h.
v4:
 - rename parser -> analyzer;
 - reorganize the analyzer patches a bit;
 - use bitfield.h directly.

--- merge blurb:
In the last year a lot of progress have been made on offloading
simpler TC classifiers.  There is also growing interest in using
BPF for generic high-speed packet processing in the kernel.
It seems beneficial to tie those two trends together and think
about hardware offloads of BPF programs.  This patch set presents
such offload to Netronome smart NICs.  cls_bpf is extended with
hardware offload capabilities and NFP driver gets a JIT translator
which in presence of capable firmware can be used to offload
the BPF program onto the card.

BPF JIT implementation is not 100% complete (e.g. missing instructions)
but it is functional.  Encouragingly it should be possible to
offload most (if not all) advanced BPF features onto the NIC -
including packet modification, maps, tunnel encap/decap etc.

Example of basic tests I used:
  __section_cls_entry
  int cls_entry(struct __sk_buff *skb)
  {
if (load_byte(skb, 0) != 0x0)
return 0;

if (load_byte(skb, 4) != 0x1)
return 0;

skb->mark = 0xcafe;

if (load_byte(skb, 50) != 0xff)
return 0;

return ~0U;
  }

Above code can be compiled with Clang and loaded like this:

ethtool -K p1p1 hw-tc-offload on
tc qdisc add dev p1p1 ingress
tc filter add dev p1p1 parent ffff:  bpf obj prog.o action drop

This set implements the basic transparent offload, the skip_{sw,hw}
flags and reporting statistics for cls_bpf.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonfp: bpf: add offload of TC direct action mode
Jakub Kicinski [Wed, 21 Sep 2016 10:44:07 +0000 (11:44 +0100)]
nfp: bpf: add offload of TC direct action mode

Add offload of TC in direct action mode.  We just need
to provide appropriate checks in the verifier and
a new outro block to translate the exit codes to what
data path expects

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonfp: bpf: add support for legacy redirect action
Jakub Kicinski [Wed, 21 Sep 2016 10:44:06 +0000 (11:44 +0100)]
nfp: bpf: add support for legacy redirect action

Data path has redirect support so expressing redirect
to the port frame came from is a trivial matter of
setting the right result code.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: act_mirred: allow statistic updates from offloaded actions
Jakub Kicinski [Wed, 21 Sep 2016 10:44:05 +0000 (11:44 +0100)]
net: act_mirred: allow statistic updates from offloaded actions

Implement .stats_update() callback.  The implementation
is generic and can be reused by other simple actions if
needed.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonfp: bpf: add packet marking support
Jakub Kicinski [Wed, 21 Sep 2016 10:44:04 +0000 (11:44 +0100)]
nfp: bpf: add packet marking support

Add missing ABI defines and eBPF instructions to allow
mark to be passed on and extend prepend parsing on the
RX path to pick it up from packet metadata.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonfp: bpf: allow offloaded filters to update stats
Jakub Kicinski [Wed, 21 Sep 2016 10:44:03 +0000 (11:44 +0100)]
nfp: bpf: allow offloaded filters to update stats

Periodically poll stats and call into offloaded actions
to update them.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: cls_bpf: allow offloaded filters to update stats
Jakub Kicinski [Wed, 21 Sep 2016 10:44:02 +0000 (11:44 +0100)]
net: cls_bpf: allow offloaded filters to update stats

Call into offloaded filters to update stats.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonfp: bpf: add hardware bpf offload
Jakub Kicinski [Wed, 21 Sep 2016 10:44:01 +0000 (11:44 +0100)]
nfp: bpf: add hardware bpf offload

Add hardware bpf offload on our smart NICs.  Detect if
capable firmware is loaded and use it to load the code JITed
with just added translator onto programmable engines.

This commit only supports offloading cls_bpf in legacy mode
(non-direct action).

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonfp: add BPF to NFP code translator
Jakub Kicinski [Wed, 21 Sep 2016 10:44:00 +0000 (11:44 +0100)]
nfp: add BPF to NFP code translator

Add translator for JITing eBPF to operations which
can be executed on NFP's programmable engines.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agobpf: recognize 64bit immediate loads as consts
Jakub Kicinski [Wed, 21 Sep 2016 10:43:59 +0000 (11:43 +0100)]
bpf: recognize 64bit immediate loads as consts

When running as parser interpret BPF_LD | BPF_IMM | BPF_DW
instructions as loading CONST_IMM with the value stored
in imm.  The verifier will continue not recognizing those
due to concerns about search space/program complexity
increase.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agobpf: enable non-core use of the verfier
Jakub Kicinski [Wed, 21 Sep 2016 10:43:58 +0000 (11:43 +0100)]
bpf: enable non-core use of the verfier

Advanced JIT compilers and translators may want to use
eBPF verifier as a base for parsers or to perform custom
checks and validations.

Add ability for external users to invoke the verifier
and provide callbacks to be invoked for every intruction
checked.  For now only add most basic callback for
per-instruction pre-interpretation checks is added.  More
advanced users may also like to have per-instruction post
callback and state comparison callback.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agobpf: expose internal verfier structures
Jakub Kicinski [Wed, 21 Sep 2016 10:43:57 +0000 (11:43 +0100)]
bpf: expose internal verfier structures

Move verifier's internal structures to a header file and
prefix their names with bpf_ to avoid potential namespace
conflicts.  Those structures will soon be used by external
analyzers.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agobpf: don't (ab)use instructions to store state
Jakub Kicinski [Wed, 21 Sep 2016 10:43:56 +0000 (11:43 +0100)]
bpf: don't (ab)use instructions to store state

Storing state in reserved fields of instructions makes
it impossible to run verifier on programs already
marked as read-only. Allocate and use an array of
per-instruction state instead.

While touching the error path rename and move existing
jump target.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: cls_bpf: add support for marking filters as hardware-only
Jakub Kicinski [Wed, 21 Sep 2016 10:43:55 +0000 (11:43 +0100)]
net: cls_bpf: add support for marking filters as hardware-only

Add cls_bpf support for the TCA_CLS_FLAGS_SKIP_SW flag.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: cls_bpf: limit hardware offload by software-only flag
Jakub Kicinski [Wed, 21 Sep 2016 10:43:54 +0000 (11:43 +0100)]
net: cls_bpf: limit hardware offload by software-only flag

Add cls_bpf support for the TCA_CLS_FLAGS_SKIP_HW flag.
Unlike U32 and flower cls_bpf already has some netlink
flags defined.  Create a new attribute to be able to use
the same flag values as the above.

Unlike U32 and flower reject unknown flags.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: cls_bpf: add hardware offload
Jakub Kicinski [Wed, 21 Sep 2016 10:43:53 +0000 (11:43 +0100)]
net: cls_bpf: add hardware offload

This patch adds hardware offload capability to cls_bpf classifier,
similar to what have been done with U32 and flower.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'mlxse-resource-query'
David S. Miller [Wed, 21 Sep 2016 05:01:09 +0000 (01:01 -0400)]
Merge branch 'mlxse-resource-query'

Jiri Pirko says:

====================
mlxsw: Replace Hw related const with resource query results

Nogah says:

Many of the ASIC's properties can be read from the HW with resources query.
This patchset adds new resources to the resource query and implement
using them, instead of the constants that we currently use.
Those resources are lag, kvd and router related.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: spectrum: Implement max rif resource
Nogah Frankel [Tue, 20 Sep 2016 09:16:57 +0000 (11:16 +0200)]
mlxsw: spectrum: Implement max rif resource

Replace max rif const with using the result from resource query.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: pci: Add max router interface resource
Nogah Frankel [Tue, 20 Sep 2016 09:16:56 +0000 (11:16 +0200)]
mlxsw: pci: Add max router interface resource

Add the max number of rif (router interfaces) to resource query.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: pci: Add some miscellaneous resources
Nogah Frankel [Tue, 20 Sep 2016 09:16:55 +0000 (11:16 +0200)]
mlxsw: pci: Add some miscellaneous resources

Add max system ports, max regions and max vlan groups to resource query.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: spectrum: Implement max virtual routers resource
Nogah Frankel [Tue, 20 Sep 2016 09:16:54 +0000 (11:16 +0200)]
mlxsw: spectrum: Implement max virtual routers resource

Replace max virtual routers const with the result from
the resource query.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: pci: Add max virtual routers resource
Nogah Frankel [Tue, 20 Sep 2016 09:16:53 +0000 (11:16 +0200)]
mlxsw: pci: Add max virtual routers resource

Add the max number of virtual routers to resource query.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: profile: Add KVD resources to profile config
Nogah Frankel [Tue, 20 Sep 2016 09:16:52 +0000 (11:16 +0200)]
mlxsw: profile: Add KVD resources to profile config

Use resources from resource query to determine values for
the profile configuration.
Add KVD determined section sizes to the resources struct.
Change the profile struct and value to match this changes.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: pci: Add KVD size relate resources
Nogah Frankel [Tue, 20 Sep 2016 09:16:51 +0000 (11:16 +0200)]
mlxsw: pci: Add KVD size relate resources

Add KVD size, and minimum sizes for the single and double
sections resources to resources query.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: spectrum: lag resources- use resources data instead of consts
Nogah Frankel [Tue, 20 Sep 2016 09:16:50 +0000 (11:16 +0200)]
mlxsw: spectrum: lag resources- use resources data instead of consts

Use max lag and max ports in lag resources as the result of resource query
instead of using const to save them.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: pci: Add lag related resources to resources query
Nogah Frankel [Tue, 20 Sep 2016 09:16:49 +0000 (11:16 +0200)]
mlxsw: pci: Add lag related resources to resources query

Add max lag and max ports in lag resources to resources query.

Signed-off-by: Nogah Frankel <nogahf@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agomlxsw: spectrum: Make offloads stats functions static
Or Gerlitz [Tue, 20 Sep 2016 05:14:08 +0000 (08:14 +0300)]
mlxsw: spectrum: Make offloads stats functions static

The offloads stats functions are local to this file, make them static.

Fixes: fc1bbb0f1831 ('mlxsw: spectrum: Implement offload stats ndo [..]')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'tcp-bbr'
David S. Miller [Wed, 21 Sep 2016 04:23:09 +0000 (00:23 -0400)]
Merge branch 'tcp-bbr'

Neal Cardwell says:

====================
tcp: BBR congestion control algorithm

This patch series implements a new TCP congestion control algorithm:
BBR (Bottleneck Bandwidth and RTT). A paper with a detailed
description of BBR will be published in ACM Queue, September-October
2016, as "BBR: Congestion-Based Congestion Control". BBR is widely
deployed in production at Google.

The patch series starts with a set of supporting infrastructure
changes, including a few that extend the congestion control
framework. The last patch adds BBR as a TCP congestion control
module. Please see individual patches for the details.

- v3 -> v4:
 - Updated tcp_bbr.c in "tcp_bbr: add BBR congestion control"
   to use const to qualify all the constant parameters.
   Thanks to Stephen Hemminger.
 - In "tcp_bbr: add BBR congestion control", remove the bbr_rate_kbps()
   function, which had a 64-bit divide that would be problematic on some
   architectures, and just use bbr_rate_bytes_per_sec() directly.
   Thanks to Kenneth Klette Jonassen for suggesting this.
 - In "tcp: switch back to proper tcp_skb_cb size check in tcp_init()",
   switched from sizeof(skb->cb) to FIELD_SIZEOF.
   Thanks to Lance Richardson for suggesting this.
 - Updated "tcp_bbr: add BBR congestion control" commit message with
   performance data, more details about deployment at Google, and
   another reminder to use fq with BBR.
 - Updated tcp_bbr.c in "tcp_bbr: add BBR congestion control"
   to use MODULE_LICENSE("Dual BSD/GPL").

- v2 -> v3: fix another issue caught by build bots:
 - adjust rate_sample struct initialization syntax to allow gcc-4.4 to compile
   the "tcp: track data delivery rate for a TCP connection" patch; also
   adjusted some similar syntax in "tcp_bbr: add BBR congestion control"

- v1 -> v2: fix issues caught by build bots:
 - fix "tcp: export data delivery rate" to use rate64 instead of rate,
   so there is a 64-bit numerator for the do_div call
 - fix conflicting definitions for minmax caused by
   "tcp: use windowed min filter library for TCP min_rtt estimation"
   with a new commit:
   tcp: cdg: rename struct minmax in tcp_cdg.c to avoid a naming conflict
 - fix warning about the use of __packed in
   "tcp: track data delivery rate for a TCP connection",
   which involves the addition of a new commit:
   tcp: switch back to proper tcp_skb_cb size check in tcp_init()
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp_bbr: add BBR congestion control
Neal Cardwell [Tue, 20 Sep 2016 03:39:23 +0000 (23:39 -0400)]
tcp_bbr: add BBR congestion control

This commit implements a new TCP congestion control algorithm: BBR
(Bottleneck Bandwidth and RTT). A detailed description of BBR will be
published in ACM Queue, Vol. 14 No. 5, September-October 2016, as
"BBR: Congestion-Based Congestion Control".

BBR has significantly increased throughput and reduced latency for
connections on Google's internal backbone networks and google.com and
YouTube Web servers.

BBR requires only changes on the sender side, not in the network or
the receiver side. Thus it can be incrementally deployed on today's
Internet, or in datacenters.

The Internet has predominantly used loss-based congestion control
(largely Reno or CUBIC) since the 1980s, relying on packet loss as the
signal to slow down. While this worked well for many years, loss-based
congestion control is unfortunately out-dated in today's networks. On
today's Internet, loss-based congestion control causes the infamous
bufferbloat problem, often causing seconds of needless queuing delay,
since it fills the bloated buffers in many last-mile links. On today's
high-speed long-haul links using commodity switches with shallow
buffers, loss-based congestion control has abysmal throughput because
it over-reacts to losses caused by transient traffic bursts.

In 1981 Kleinrock and Gale showed that the optimal operating point for
a network maximizes delivered bandwidth while minimizing delay and
loss, not only for single connections but for the network as a
whole. Finding that optimal operating point has been elusive, since
any single network measurement is ambiguous: network measurements are
the result of both bandwidth and propagation delay, and those two
cannot be measured simultaneously.

While it is impossible to disambiguate any single bandwidth or RTT
measurement, a connection's behavior over time tells a clearer
story. BBR uses a measurement strategy designed to resolve this
ambiguity. It combines these measurements with a robust servo loop
using recent control systems advances to implement a distributed
congestion control algorithm that reacts to actual congestion, not
packet loss or transient queue delay, and is designed to converge with
high probability to a point near the optimal operating point.

In a nutshell, BBR creates an explicit model of the network pipe by
sequentially probing the bottleneck bandwidth and RTT. On the arrival
of each ACK, BBR derives the current delivery rate of the last round
trip, and feeds it through a windowed max-filter to estimate the
bottleneck bandwidth. Conversely it uses a windowed min-filter to
estimate the round trip propagation delay. The max-filtered bandwidth
and min-filtered RTT estimates form BBR's model of the network pipe.

Using its model, BBR sets control parameters to govern sending
behavior. The primary control is the pacing rate: BBR applies a gain
multiplier to transmit faster or slower than the observed bottleneck
bandwidth. The conventional congestion window (cwnd) is now the
secondary control; the cwnd is set to a small multiple of the
estimated BDP (bandwidth-delay product) in order to allow full
utilization and bandwidth probing while bounding the potential amount
of queue at the bottleneck.

When a BBR connection starts, it enters STARTUP mode and applies a
high gain to perform an exponential search to quickly probe the
bottleneck bandwidth (doubling its sending rate each round trip, like
slow start). However, instead of continuing until it fills up the
buffer (i.e. a loss), or until delay or ACK spacing reaches some
threshold (like Hystart), it uses its model of the pipe to estimate
when that pipe is full: it estimates the pipe is full when it notices
the estimated bandwidth has stopped growing. At that point it exits
STARTUP and enters DRAIN mode, where it reduces its pacing rate to
drain the queue it estimates it has created.

Then BBR enters steady state. In steady state, PROBE_BW mode cycles
between first pacing faster to probe for more bandwidth, then pacing
slower to drain any queue that created if no more bandwidth was
available, and then cruising at the estimated bandwidth to utilize the
pipe without creating excess queue. Occasionally, on an as-needed
basis, it sends significantly slower to probe for RTT (PROBE_RTT
mode).

BBR has been fully deployed on Google's wide-area backbone networks
and we're experimenting with BBR on Google.com and YouTube on a global
scale.  Replacing CUBIC with BBR has resulted in significant
improvements in network latency and application (RPC, browser, and
video) metrics. For more details please refer to our upcoming ACM
Queue publication.

Example performance results, to illustrate the difference between BBR
and CUBIC:

Resilience to random loss (e.g. from shallow buffers):
  Consider a netperf TCP_STREAM test lasting 30 secs on an emulated
  path with a 10Gbps bottleneck, 100ms RTT, and 1% packet loss
  rate. CUBIC gets 3.27 Mbps, and BBR gets 9150 Mbps (2798x higher).

Low latency with the bloated buffers common in today's last-mile links:
  Consider a netperf TCP_STREAM test lasting 120 secs on an emulated
  path with a 10Mbps bottleneck, 40ms RTT, and 1000-packet bottleneck
  buffer. Both fully utilize the bottleneck bandwidth, but BBR
  achieves this with a median RTT 25x lower (43 ms instead of 1.09
  secs).

Our long-term goal is to improve the congestion control algorithms
used on the Internet. We are hopeful that BBR can help advance the
efforts toward this goal, and motivate the community to do further
research.

Test results, performance evaluations, feedback, and BBR-related
discussions are very welcome in the public e-mail list for BBR:

  https://groups.google.com/forum/#!forum/bbr-dev

NOTE: BBR *must* be used with the fq qdisc ("man tc-fq") with pacing
enabled, since pacing is integral to the BBR design and
implementation. BBR without pacing would not function properly, and
may incur unnecessary high packet loss rates.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: increase ICSK_CA_PRIV_SIZE from 64 bytes to 88
Neal Cardwell [Tue, 20 Sep 2016 03:39:22 +0000 (23:39 -0400)]
tcp: increase ICSK_CA_PRIV_SIZE from 64 bytes to 88

The TCP CUBIC module already uses 64 bytes.
The upcoming TCP BBR module uses 88 bytes.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: new CC hook to set sending rate with rate_sample in any CA state
Yuchung Cheng [Tue, 20 Sep 2016 03:39:21 +0000 (23:39 -0400)]
tcp: new CC hook to set sending rate with rate_sample in any CA state

This commit introduces an optional new "omnipotent" hook,
cong_control(), for congestion control modules. The cong_control()
function is called at the end of processing an ACK (i.e., after
updating sequence numbers, the SACK scoreboard, and loss
detection). At that moment we have precise delivery rate information
the congestion control module can use to control the sending behavior
(using cwnd, TSO skb size, and pacing rate) in any CA state.

This function can also be used by a congestion control that prefers
not to use the default cwnd reduction approach (i.e., the PRR
algorithm) during CA_Recovery to control the cwnd and sending rate
during loss recovery.

We take advantage of the fact that recent changes defer the
retransmission or transmission of new data (e.g. by F-RTO) in recovery
until the new tcp_cong_control() function is run.

With this commit, we only run tcp_update_pacing_rate() if the
congestion control is not using this new API. New congestion controls
which use the new API do not want the TCP stack to run the default
pacing rate calculation and overwrite whatever pacing rate they have
chosen at initialization time.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: allow congestion control to expand send buffer differently
Yuchung Cheng [Tue, 20 Sep 2016 03:39:20 +0000 (23:39 -0400)]
tcp: allow congestion control to expand send buffer differently

Currently the TCP send buffer expands to twice cwnd, in order to allow
limited transmits in the CA_Recovery state. This assumes that cwnd
does not increase in the CA_Recovery.

For some congestion control algorithms, like the upcoming BBR module,
if the losses in recovery do not indicate congestion then we may
continue to raise cwnd multiplicatively in recovery. In such cases the
current multiplier will falsely limit the sending rate, much as if it
were limited by the application.

This commit adds an optional congestion control callback to use a
different multiplier to expand the TCP send buffer. For congestion
control modules that do not specificy this callback, TCP continues to
use the previous default of 2.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: export tcp_mss_to_mtu() for congestion control modules
Neal Cardwell [Tue, 20 Sep 2016 03:39:19 +0000 (23:39 -0400)]
tcp: export tcp_mss_to_mtu() for congestion control modules

Export tcp_mss_to_mtu(), so that congestion control modules can use
this to help calculate a pacing rate.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: export tcp_tso_autosize() and parameterize minimum number of TSO segments
Neal Cardwell [Tue, 20 Sep 2016 03:39:18 +0000 (23:39 -0400)]
tcp: export tcp_tso_autosize() and parameterize minimum number of TSO segments

To allow congestion control modules to use the default TSO auto-sizing
algorithm as one of the ingredients in their own decision about TSO sizing:

1) Export tcp_tso_autosize() so that CC modules can use it.

2) Change tcp_tso_autosize() to allow callers to specify a minimum
   number of segments per TSO skb, in case the congestion control
   module has a different notion of the best floor for TSO skbs for
   the connection right now. For very low-rate paths or policed
   connections it can be appropriate to use smaller TSO skbs.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: allow congestion control module to request TSO skb segment count
Neal Cardwell [Tue, 20 Sep 2016 03:39:17 +0000 (23:39 -0400)]
tcp: allow congestion control module to request TSO skb segment count

Add the tso_segs_goal() function in tcp_congestion_ops to allow the
congestion control module to specify the number of segments that
should be in a TSO skb sent by tcp_write_xmit() and
tcp_xmit_retransmit_queue(). The congestion control module can either
request a particular number of segments in TSO skb that we transmit,
or return 0 if it doesn't care.

This allows the upcoming BBR congestion control module to select small
TSO skb sizes if the module detects that the bottleneck bandwidth is
very low, or that the connection is policed to a low rate.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: export data delivery rate
Yuchung Cheng [Tue, 20 Sep 2016 03:39:16 +0000 (23:39 -0400)]
tcp: export data delivery rate

This commit export two new fields in struct tcp_info:

  tcpi_delivery_rate: The most recent goodput, as measured by
    tcp_rate_gen(). If the socket is limited by the sending
    application (e.g., no data to send), it reports the highest
    measurement instead of the most recent. The unit is bytes per
    second (like other rate fields in tcp_info).

  tcpi_delivery_rate_app_limited: A boolean indicating if the goodput
    was measured when the socket's throughput was limited by the
    sending application.

This delivery rate information can be useful for applications that
want to know the current throughput the TCP connection is seeing,
e.g. adaptive bitrate video streaming. It can also be very useful for
debugging or troubleshooting.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: track application-limited rate samples
Soheil Hassas Yeganeh [Tue, 20 Sep 2016 03:39:15 +0000 (23:39 -0400)]
tcp: track application-limited rate samples

This commit adds code to track whether the delivery rate represented
by each rate_sample was limited by the application.

Upon each transmit, we store in the is_app_limited field in the skb a
boolean bit indicating whether there is a known "bubble in the pipe":
a point in the rate sample interval where the sender was
application-limited, and did not transmit even though the cwnd and
pacing rate allowed it.

This logic marks the flow app-limited on a write if *all* of the
following are true:

  1) There is less than 1 MSS of unsent data in the write queue
     available to transmit.

  2) There is no packet in the sender's queues (e.g. in fq or the NIC
     tx queue).

  3) The connection is not limited by cwnd.

  4) There are no lost packets to retransmit.

The tcp_rate_check_app_limited() code in tcp_rate.c determines whether
the connection is application-limited at the moment. If the flow is
application-limited, it sets the tp->app_limited field. If the flow is
application-limited then that means there is effectively a "bubble" of
silence in the pipe now, and this silence will be reflected in a lower
bandwidth sample for any rate samples from now until we get an ACK
indicating this bubble has exited the pipe: specifically, until we get
an ACK for the next packet we transmit.

When we send every skb we record in scb->tx.is_app_limited whether the
resulting rate sample will be application-limited.

The code in tcp_rate_gen() checks to see when it is safe to mark all
known application-limited bubbles of silence as having exited the
pipe. It does this by checking to see when the delivered count moves
past the tp->app_limited marker. At this point it zeroes the
tp->app_limited marker, as all known bubbles are out of the pipe.

We make room for the tx.is_app_limited bit in the skb by borrowing a
bit from the in_flight field used by NV to record the number of bytes
in flight. The receive window in the TCP header is 16 bits, and the
max receive window scaling shift factor is 14 (RFC 1323). So the max
receive window offered by the TCP protocol is 2^(16+14) = 2^30. So we
only need 30 bits for the tx.in_flight used by NV.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: track data delivery rate for a TCP connection
Yuchung Cheng [Tue, 20 Sep 2016 03:39:14 +0000 (23:39 -0400)]
tcp: track data delivery rate for a TCP connection

This patch generates data delivery rate (throughput) samples on a
per-ACK basis. These rate samples can be used by congestion control
modules, and specifically will be used by TCP BBR in later patches in
this series.

Key state:

tp->delivered: Tracks the total number of data packets (original or not)
       delivered so far. This is an already-existing field.

tp->delivered_mstamp: the last time tp->delivered was updated.

Algorithm:

A rate sample is calculated as (d1 - d0)/(t1 - t0) on a per-ACK basis:

  d1: the current tp->delivered after processing the ACK
  t1: the current time after processing the ACK

  d0: the prior tp->delivered when the acked skb was transmitted
  t0: the prior tp->delivered_mstamp when the acked skb was transmitted

When an skb is transmitted, we snapshot d0 and t0 in its control
block in tcp_rate_skb_sent().

When an ACK arrives, it may SACK and ACK some skbs. For each SACKed
or ACKed skb, tcp_rate_skb_delivered() updates the rate_sample struct
to reflect the latest (d0, t0).

Finally, tcp_rate_gen() generates a rate sample by storing
(d1 - d0) in rs->delivered and (t1 - t0) in rs->interval_us.

One caveat: if an skb was sent with no packets in flight, then
tp->delivered_mstamp may be either invalid (if the connection is
starting) or outdated (if the connection was idle). In that case,
we'll re-stamp tp->delivered_mstamp.

At first glance it seems t0 should always be the time when an skb was
transmitted, but actually this could over-estimate the rate due to
phase mismatch between transmit and ACK events. To track the delivery
rate, we ensure that if packets are in flight then t0 and and t1 are
times at which packets were marked delivered.

If the initial and final RTTs are different then one may be corrupted
by some sort of noise. The noise we see most often is sending gaps
caused by delayed, compressed, or stretched acks. This either affects
both RTTs equally or artificially reduces the final RTT. We approach
this by recording the info we need to compute the initial RTT
(duration of the "send phase" of the window) when we recorded the
associated inflight. Then, for a filter to avoid bandwidth
overestimates, we generalize the per-sample bandwidth computation
from:

    bw = delivered / ack_phase_rtt

to the following:

    bw = delivered / max(send_phase_rtt, ack_phase_rtt)

In large-scale experiments, this filtering approach incorporating
send_phase_rtt is effective at avoiding bandwidth overestimates due to
ACK compression or stretched ACKs.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: count packets marked lost for a TCP connection
Neal Cardwell [Tue, 20 Sep 2016 03:39:13 +0000 (23:39 -0400)]
tcp: count packets marked lost for a TCP connection

Count the number of packets that a TCP connection marks lost.

Congestion control modules can use this loss rate information for more
intelligent decisions about how fast to send.

Specifically, this is used in TCP BBR policer detection. BBR uses a
high packet loss rate as one signal in its policer detection and
policer bandwidth estimation algorithm.

The BBR policer detection algorithm cannot simply track retransmits,
because a retransmit can be (and often is) an indicator of packets
lost long, long ago. This is particularly true in a long CA_Loss
period that repairs the initial massive losses when a policer kicks
in.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: switch back to proper tcp_skb_cb size check in tcp_init()
Eric Dumazet [Tue, 20 Sep 2016 03:39:12 +0000 (23:39 -0400)]
tcp: switch back to proper tcp_skb_cb size check in tcp_init()

Revert to the tcp_skb_cb size check that tcp_init() had before commit
b4772ef879a8 ("net: use common macro for assering skb->cb[] available
size in protocol families"). As related commit 744d5a3e9fe2 ("net:
move skb->dropcount to skb->cb[]") explains, the
sock_skb_cb_check_size() mechanism was added to ensure that there is
space for dropcount, "for protocol families using it". But TCP is not
a protocol using dropcount, so tcp_init() doesn't need to provision
space for dropcount in the skb->cb[], and thus we can revert to the
older form of the tcp_skb_cb size check. Doing so allows TCP to use 4
more bytes of the skb->cb[] space.

Fixes: b4772ef879a8 ("net: use common macro for assering skb->cb[] available size in protocol families")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet_sched: sch_fq: add low_rate_threshold parameter
Eric Dumazet [Tue, 20 Sep 2016 03:39:11 +0000 (23:39 -0400)]
net_sched: sch_fq: add low_rate_threshold parameter

This commit adds to the fq module a low_rate_threshold parameter to
insert a delay after all packets if the socket requests a pacing rate
below the threshold.

This helps achieve more precise control of the sending rate with
low-rate paths, especially policers. The basic issue is that if a
congestion control module detects a policer at a certain rate, it may
want fq to be able to shape to that policed rate. That way the sender
can avoid policer drops by having the packets arrive at the policer at
or just under the policed rate.

The default threshold of 550Kbps was chosen analytically so that for
policers or links at 500Kbps or 512Kbps fq would very likely invoke
this mechanism, even if the pacing rate was briefly slightly above the
available bandwidth. This value was then empirically validated with
two years of production testing on YouTube video servers.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: use windowed min filter library for TCP min_rtt estimation
Neal Cardwell [Tue, 20 Sep 2016 03:39:10 +0000 (23:39 -0400)]
tcp: use windowed min filter library for TCP min_rtt estimation

Refactor the TCP min_rtt code to reuse the new win_minmax library in
lib/win_minmax.c to simplify the TCP code.

This is a pure refactor: the functionality is exactly the same. We
just moved the windowed min code to make TCP easier to read and
maintain, and to allow other parts of the kernel to use the windowed
min/max filter code.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agolib/win_minmax: windowed min or max estimator
Neal Cardwell [Tue, 20 Sep 2016 03:39:09 +0000 (23:39 -0400)]
lib/win_minmax: windowed min or max estimator

This commit introduces a generic library to estimate either the min or
max value of a time-varying variable over a recent time window. This
is code originally from Kathleen Nichols. The current form of the code
is from Van Jacobson.

A single struct minmax_sample will track the estimated windowed-max
value of the series if you call minmax_running_max() or the estimated
windowed-min value of the series if you call minmax_running_min().

Nearly equivalent code is already in place for minimum RTT estimation
in the TCP stack. This commit extracts that code and generalizes it to
handle both min and max. Moving the code here reduces the footprint
and complexity of the TCP code base and makes the filter generally
available for other parts of the codebase, including an upcoming TCP
congestion control module.

This library works well for time series where the measurements are
smoothly increasing or decreasing.

Signed-off-by: Van Jacobson <vanj@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agotcp: cdg: rename struct minmax in tcp_cdg.c to avoid a naming conflict
Soheil Hassas Yeganeh [Tue, 20 Sep 2016 03:39:08 +0000 (23:39 -0400)]
tcp: cdg: rename struct minmax in tcp_cdg.c to avoid a naming conflict

The upcoming change "lib/win_minmax: windowed min or max estimator"
introduces a struct called minmax, which is then included in
include/linux/tcp.h in the upcoming change "tcp: use windowed min
filter library for TCP min_rtt estimation". This would create a
compilation error for tcp_cdg.c, which defines its own minmax
struct. To avoid this naming conflict (and potentially others in the
future), this commit renames the version used in tcp_cdg.c to
cdg_minmax.

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Kenneth Klette Jonassen <kennetkl@ifi.uio.no>
Acked-by: Kenneth Klette Jonassen <kennetkl@ifi.uio.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: ethernet: mediatek: enhance with avoiding superfluous assignment inside mtk_get_...
Sean Wang [Tue, 20 Sep 2016 03:26:48 +0000 (11:26 +0800)]
net: ethernet: mediatek: enhance with avoiding superfluous assignment inside mtk_get_ethtool_stats

data_src is unchanged inside the loop, so this patch moves
the assignment to outside the loop to avoid unnecessarily
assignment

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet: dsa: mv88e6xxx: handle multiple ports in ATU
Vivien Didelot [Mon, 19 Sep 2016 23:56:11 +0000 (19:56 -0400)]
net: dsa: mv88e6xxx: handle multiple ports in ATU

An address can be loaded in the ATU with multiple ports, for instance
when adding multiple ports to a Multicast group with "bridge mdb".

The current code doesn't allow that. Add an helper to get a single entry
from the ATU, then set or clear the requested port, before loading the
entry back in the ATU.

Note that the required _mv88e6xxx_atu_getnext function is defined below
mv88e6xxx_port_db_load_purge, so forward-declare it for the moment. The
ATU code will be isolated in future patches.

Fixes: 83dabd1fa84c ("net: dsa: mv88e6xxx: make switchdev DB ops generic")
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agonet sched actions: fix GETing actions
Jamal Hadi Salim [Mon, 19 Sep 2016 23:02:51 +0000 (19:02 -0400)]
net sched actions: fix GETing actions

With the batch changes that translated transient actions into
a temporary list lost in the translation was the fact that
tcf_action_destroy() will eventually delete the action from
the permanent location if the refcount is zero.

Example of what broke:
...add a gact action to drop
sudo $TC actions add action drop index 10
...now retrieve it, looks good
sudo $TC actions get action gact index 10
...retrieve it again and find it is gone!
sudo $TC actions get action gact index 10

Fixes: 22dc13c837c3 ("net_sched: convert tcf_exts from list to pointer array"),
Fixes: 824a7e8863b3 ("net_sched: remove an unnecessary list_del()")
Fixes: f07fed82ad79 ("net_sched: remove the leftover cleanup_a()")

Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agoMerge branch 'bpf-direct-packet-access-improvements'
David S. Miller [Wed, 21 Sep 2016 03:32:19 +0000 (23:32 -0400)]
Merge branch 'bpf-direct-packet-access-improvements'

Daniel Borkmann says:

====================
BPF direct packet access improvements

This set adds write support to the currently available read support
for {cls,act}_bpf programs. First one is a fix for affected commit
sitting in net-next and prerequisite for the second one, last patch
adds a number of test cases against the verifier. For details, please
see individual patches.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agobpf: add test cases for direct packet access
Daniel Borkmann [Mon, 19 Sep 2016 22:26:14 +0000 (00:26 +0200)]
bpf: add test cases for direct packet access

Add couple of test cases for direct write and the negative size issue, and
also adjust the direct packet access test4 since it asserts that writes are
not possible, but since we've just added support for writes, we need to
invert the verdict to ACCEPT, of course. Summary: 133 PASSED, 0 FAILED.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
8 years agobpf: direct packet write and access for helpers for clsact progs
Daniel Borkmann [Mon, 19 Sep 2016 22:26:13 +0000 (00:26 +0200)]
bpf: direct packet write and access for helpers for clsact progs

This work implements direct packet access for helpers and direct packet
write in a similar fashion as already available for XDP types via commits
4acf6c0b84c9 ("bpf: enable direct packet data write for xdp progs") and
6841de8b0d03 ("bpf: allow helpers access the packet directly"), and as a
complementary feature to the already available direct packet read for tc
(cls/act) programs.

For enabling this, we need to introduce two helpers, bpf_skb_pull_data()
and bpf_csum_update(). The first is generally needed for both, read and
write, because they would otherwise only be limited to the current linear
skb head. Usually, when the data_end test fails, programs just bail out,
or, in the direct read case, use bpf_skb_load_bytes() as an alternative
to overcome this limitation. If such data sits in non-linear parts, we
can just pull them in once with the new helper, retest and eventually
access them.

At the same time, this also makes sure the skb is uncloned, which is, of
course, a necessary condition for direct write. As this needs to be an
invariant for the write part only, the verifier detects writes and adds
a prologue that is calling bpf_skb_pull_data() to effectively unclone the
skb from the very beginning in case it is indeed cloned. The heuristic
makes use of a similar trick that was done in 233577a22089 ("net: filter:
constify detection of pkt_type_offset"). This comes at zero cost for other
programs that do not use the direct write feature. Should a program use
this feature only sparsely and has read access for the most parts with,
for example, drop return codes, then such write action can be delegated
to a tail called program for mitigating this cost of potential uncloning
to a late point in time where it would have been paid similarly with the
bpf_skb_store_bytes() as well. Advantage of direct write is that the
writes are inlined whereas the helper cannot make any length assumptions
and thus needs to generate a call to memcpy() also for small sizes, as well
as cost of helper call itself with sanity checks are avoided. Plus, when
direct read is already used, we don't need to cache or perform rechecks
on the data boundaries (due to verifier invalidating previous checks for
helpers that change skb->data), so more complex programs using rewrites
can benefit from switching to direct read plus write.

For direct packet access to helpers, we save the otherwise needed copy into
a temp struct sitting on stack memory when use-case allows. Both facilities
are enabled via may_access_direct_pkt_data() in verifier. For now, we limit
this to map helpers and csum_diff, and can successively enable other helpers
where we find it makes sense. Helpers that definitely cannot be allowed for
this are those part of bpf_helper_changes_skb_data() since they can change
underlying data, and those that write into memory as this could happen for
packet typed args when still cloned. bpf_csum_update() helper accommodates
for the fact that we need to fixup checksum_complete when using direct write
instead of bpf_skb_store_bytes(), meaning the programs can use available
helpers like bpf_csum_diff(), and implement csum_add(), csum_sub(),
csum_block_add(), csum_block_sub() equivalents in eBPF together with the
new helper. A usage example will be provided for iproute2's examples/bpf/
directory.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>