As we know that AVB is enabled by default, and the ENET IP design is
queue 0 for best effort, queue 1&2 for AVB Class A&B. Bandwidth of each
queue 1&2 set in driver is 50%, TX bandwidth fluctuated when selecting
tx queues randomly with FEC_QUIRK_HAS_AVB quirk available.

This patch adds ndo_select_queue callback to select queues for
transmitting to fix this issue. It will always return queue 0 if this is
not a vlan packet, and return queue 1 or 2 based on priority of vlan
packet.

You may complain that in fact we only use single queue for trasmitting
if we are not targeted to VLAN. Yes, but seems we have no choice, since
AVB is enabled when the driver probed, we can't switch this feature
dynamicly. After compare multiple queues to single queue, TX throughput
almost no improvement.

One way we can implemet is to configure the driver to multiple queues
with Round-robin scheme by default. Then add ndo_setup_tc callback to
enable/disable AVB feature for users. Unfortunately, ENET AVB IP seems
not follow the standard 802.1Qav spec. We only can program
DMAnCFG[IDLE_SLOPE] field to calculate bandwidth fraction. And idle
slope is restricted to certain valus (a total of 19). It's far away from
CBS QDisc implemented in Linux TC framework. If you strongly suggest to do
this, I think we only can support limited numbers of bandwidth and reject
others, but it's really urgly and wried.

With this patch, VLAN tagged packets route to queue 0/1/2 based on vlan
priority; VLAN untagged packets route to queue 0.

Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reported-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>

Frieder Schrempf reported a TX throuthput issue [1], it happens quite often
that the measured bandwidth in TX direction drops from its expected/nominal
value to something like ~50% (for 100M) or ~67% (for 1G) connections.

[1] https://lore.kernel.org/linux-arm-kernel/421cc86c-b66f-b372-32f7-21e59f9a98bc@kontron.de/

The issue becomes clear after digging into it, Net core would select
queues when transmitting packets. Since FEC have not impletemented
ndo_select_queue callback yet, so it will call netdev_pick_tx to select
queues randomly.

For i.MX6SX ENET IP with AVB support, driver default enables this
feature. According to the setting of QOS/RCMRn/DMAnCFG registers, AVB
configured to Credit-based scheme, 50% bandwidth of each queue 1&2.

With below tests let me think more:
1) With FEC_QUIRK_HAS_AVB quirk, can reproduce TX bandwidth fluctuations issue.
2) Without FEC_QUIRK_HAS_AVB quirk, can't reproduce TX bandwidth fluctuations issue.

The related difference with or w/o FEC_QUIRK_HAS_AVB quirk is that, whether we
program FTYPE field of TxBD or not. As I describe above, AVB feature is
enabled by default. With FEC_QUIRK_HAS_AVB quirk, frames in queue 0
marked as non-AVB, and frames in queue 1&2 marked as AVB Class A&B. It's
unreasonable if frames in queue 1&2 are not required to be time-sensitive.
So when Net core select tx queues ramdomly, Credit-based scheme would work
and lead to TX bandwidth fluctuated. On the other hand, w/o
FEC_QUIRK_HAS_AVB quirk, frames in queue 1&2 are all marked as non-AVB, so
Credit-based scheme would not work.

Till now, how can we fix this TX throughput issue? Yes, please remove
FEC_QUIRK_HAS_AVB quirk if you suffer it from time-nonsensitive networking.
However, this quirk is used to indicate i.MX6SX, other setting depends
on it. So this patch adds a new quirk FEC_QUIRK_HAS_MULTI_QUEUES to
represent i.MX6SX, it is safe for us remove FEC_QUIRK_HAS_AVB quirk
now.

FEC_QUIRK_HAS_AVB quirk is set by default in the driver, and users may
not know much about driver details, they would waste effort to find the
root cause, that is not we want. The following patch is a implementation
to fix it and users don't need to modify the driver.

Tested-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Reported-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>

Using eth_zero_addr() to assign zero address insetad of
inefficient copy from an array.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Peng Li says:

====================
net: cosa: clean up some code style issues

This patchset clean up some code style issues.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

According to the chackpatch.pl,
no spaces is necessary at the start of a line,
no space is necessary after a cast.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch removes trailing whitespaces.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add space required before the open parenthesis '(' and '{'.
Add space required after that close brace '}' and ','
Add spaces required around that '=' , '&', '*', '|', '+', '/' and '-'.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Trailing statements should be on next line.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alignment should match open parenthesis.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch uses the BIT macro for setting individual bits,
to fix the following checkpatch.pl issue:
CHECK: Prefer using the BIT macro.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Macro argument 'cosa' may be better as '(cosa)' to avoid
precedence issues.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch removes redundant braces {}, to fix the
checkpatch.pl warning:
"braces {} are not necessary for single statement blocks".

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Braces {} should be used on all arms of this statement.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Networking block comments don't use an empty /* line,
use /* Comment...

Block comments use * on subsequent lines.
Block comments use a trailing */ on a separate line.

This patch fixes the comments style issues.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Should not use assignment in if condition.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to the chackpatch.pl, comparison to NULL could
be written "!chan->rx_skb".

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the checkpatch error as "foo* bar" should be "foo *bar".

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes the checkpatch error about missing a blank line
after declarations.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch removes some redundant blank lines.

Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Convert list_for_each() to list_for_each_entry() where
applicable. This simplifies the code.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There has been a few errors in the ethtool reply size calculations,
most of those are hard to trigger during basic testing because of
skb size rounding up and netdev names being shorter than max.
Add a more precise check.

This change will affect the value of payload length displayed in
case of -EMSGSIZE but that should be okay, "payload length" isn't
a well defined term here.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Timewait sockets have included mark since approx 4.18.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Jon Maxwell <jmaxwell37@gmail.com>
Fixes: 0048369 ("tcp: Add mark for TIMEWAIT sockets")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This symbol is not used outside of net.c, so marks it static.

Fix the following sparse warning:

drivers/net/mhi/net.c:385:23: warning: symbol 'mhi_wwan_ops' was not
declared. Should it be static?

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Guangbin Huang says:

====================
net: hns3: updates for -next

This series includes some optimization in IO path for the HNS3 ethernet
driver.
====================

Cc: Loic Poulain <loic.poulain@linaro.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently rx page will be reused to receive future packet when
the stack releases the previous skb quickly. If the old page
can not be reused, a new page will be allocated and mapped,
which comsumes a lot of cpu when IOMMU is in the strict mode,
especially when the application and irq/NAPI happens to run on
the same cpu.

So allocate a new frag to memcpy the data to avoid the costly
IOMMU unmapping/mapping operation, and add "frag_alloc_err"
and "frag_alloc" stats in "ethtool -S ethX" cmd.

The throughput improves above 50% when running single thread of
iperf using TCP when IOMMU is in strict mode and iperf shares the
same cpu with irq/NAPI(rx_copybreak = 2048 and mtu = 1500).

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Current rx page offset only reset to zero when all the below
conditions are satisfied:
1. rx page is only owned by driver.
2. rx page is reusable.
3. the page offset that is above to be given to the stack has
reached the end of the page.

If the page offset is over the hns3_buf_size(), it means the
buffer below the offset of the page is usable when the above
condition 1 & 2 are satisfied, so page offset can be reset to
zero instead of increasing the offset. We may be able to always
reuse the first 4K buffer of a 64K page, which means we can
limit the hot buffer size as much as possible.

The above optimization is a side effect when refacting the
rx page reuse handling in order to support the rx copybreak.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Using the queue based tx buffer, it is also possible to allocate a
sgl buffer, and use skb_to_sgvec() to convert the skb to the sgvec
in order to support the dma_map_sg() to decreases the overhead of
IOMMU mapping and unmapping.

Firstly, it reduces the number of buffers. For example, a tcp skb
may have a 66-byte header and 3 fragments of 4328, 32768, and 28064
bytes. With this patch, dma_map_sg() will combine them into two
buffers, 66-bytes header and one 65160-bytes fragment by using IOMMU.

Secondly, it reduces the number of dma mapping and unmapping. All the
original 4 buffers are mapped only once rather than 4 times.

The throughput improves above 10% when running single thread of iperf
using TCP when IOMMU is in strict mode.

Suggested-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support to query tx spare buffer size from configuration
file, and use this info to do spare buffer initialization when
the module parameter 'tx_spare_buf_size' is not specified.

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

when the packet or frag size is small, it causes both security and
performance issue. As dma can't map sub-page, this means some extra
kernel data is visible to devices. On the other hand, the overhead
of dma map and unmap is huge when IOMMU is on.

So add a queue based tx shared bounce buffer to memcpy the small
packet when the len of the xmitted skb is below tx_copybreak.
Add tx_spare_buf_size module param to set the size of tx spare
buffer, and add set/get_tunable to set or query the tx_copybreak.

The throughtput improves from 30 Gbps to 90+ Gbps when running 16
netperf threads with 32KB UDP message size when IOMMU is in the
strict mode(tx_copybreak = 2000 and mtu = 1500).

Suggested-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Factor out hns3_fill_desc() so that it can be reused in the
tx bounce supporting.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

desc_cb is used to store mapping and freeing info for the
corresponding desc, which is used in the cleaning process.
There will be more desc_cb type coming up when supporting the
tx bounce buffer, change desc_cb type to bit-wise value in order
to reduce the desc_cb type checking operation in the data path.

Also move the desc_cb type definition to hns3_enet.h because it
is only used in hns3_enet.c, and declare a local variable desc_cb
in hns3_clear_desc() to reduce lines of code.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As already done for mvneta and mvpp2, enable skb recycling for ti
ethernet drivers

ti driver on net-next:
----------------------
[perf top]
 47.15%  [kernel]     [k] _raw_spin_unlock_irqrestore
 11.77%  [kernel]     [k] __cpdma_chan_free
  3.16%  [kernel]     [k] ___bpf_prog_run
  2.52%  [kernel]     [k] cpsw_rx_vlan_encap
  2.34%  [kernel]     [k] __netif_receive_skb_core
  2.27%  [kernel]     [k] free_unref_page
  2.26%  [kernel]     [k] kmem_cache_free
  2.24%  [kernel]     [k] kmem_cache_alloc
  1.69%  [kernel]     [k] __softirqentry_text_start
  1.61%  [kernel]     [k] cpsw_rx_handler
  1.19%  [kernel]     [k] page_pool_release_page
  1.19%  [kernel]     [k] clear_bits_ll
  1.15%  [kernel]     [k] page_frag_free
  1.06%  [kernel]     [k] __dma_page_dev_to_cpu
  0.99%  [kernel]     [k] memset
  0.94%  [kernel]     [k] __alloc_pages_bulk
  0.92%  [kernel]     [k] kfree_skb
  0.85%  [kernel]     [k] packet_rcv
  0.78%  [kernel]     [k] page_address
  0.75%  [kernel]     [k] v7_dma_inv_range
  0.71%  [kernel]     [k] __lock_text_start

[iperf3 tcp]
[  5]   0.00-10.00  sec   873 MBytes   732 Mbits/sec    0   sender
[  5]   0.00-10.01  sec   866 MBytes   726 Mbits/sec        receiver

ti + skb recycling:
-------------------
[perf top]
 40.58%  [kernel]    [k] _raw_spin_unlock_irqrestore
 16.18%  [kernel]    [k] __softirqentry_text_start
 10.33%  [kernel]    [k] __cpdma_chan_free
  2.62%  [kernel]    [k] ___bpf_prog_run
  2.05%  [kernel]    [k] cpsw_rx_vlan_encap
  2.00%  [kernel]    [k] kmem_cache_alloc
  1.86%  [kernel]    [k] __netif_receive_skb_core
  1.80%  [kernel]    [k] kmem_cache_free
  1.63%  [kernel]    [k] cpsw_rx_handler
  1.12%  [kernel]    [k] cpsw_rx_mq_poll
  1.11%  [kernel]    [k] page_pool_put_page
  1.04%  [kernel]    [k] _raw_spin_unlock
  0.97%  [kernel]    [k] clear_bits_ll
  0.90%  [kernel]    [k] packet_rcv
  0.88%  [kernel]    [k] __dma_page_dev_to_cpu
  0.85%  [kernel]    [k] kfree_skb
  0.80%  [kernel]    [k] memset
  0.71%  [kernel]    [k] __lock_text_start
  0.66%  [kernel]    [k] v7_dma_inv_range
  0.64%  [kernel]    [k] gen_pool_free_owner

[iperf3 tcp]
[  5]   0.00-10.00  sec   884 MBytes   742 Mbits/sec    0   sender
[  5]   0.00-10.01  sec   878 MBytes   735 Mbits/sec        receiver

Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes .rst file warnings seen on linux-next build.

Fixes: f7af616 ("net: iosm: infrastructure")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: M Chetan Kumar <m.chetan.kumar@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a spelling mistake in a dev_err message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>