The current/old tx path design was that host, at
its own leisure, pushed tx frames to the device.
For HTT there was ~1000-1400 msdu queue depth.

After reaching that limit the driver would request
mac80211 to stop queues. There was little control
over what packets got in there as far as
DA/RA was considered so it was rather easy to
starve per-station traffic flows.

With MU-MIMO this became a significant problem
because the queue depth was insufficient to buffer
frames from multiple clients (which could have
different signal quality and capabilities) in an
efficient fashion.

Hence the new tx path in 10.4 was introduced: a
pull-push mode.

Firmware and host can share tx queue state via
DMA. The state is logically a 2 dimensional array
addressed via peer_id+tid pair. Each entry is a
counter (either number of bytes or packets. Host
keeps it updated and firmware uses it for
scheduling Tx pull requests to host.

This allows MU-MIMO to become a lot more effective
with 10+ clients.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

This will be necessary for later.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

This will be necessary for later.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

Firmware 10.4.3 onwards can support a pull-push Tx
model where it shares a Tx queue state with the
host.

The host updates the DMA region it pointed to
during HTT setup whenever number of software
queued from (on host) changes. Based on this
information firmware issues fetch requests to the
host telling the host how many frames from a list
of given stations/tids should be submitted to the
firmware.

The code won't be called because not all
appropriate HTT events are processed yet.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

This implements very basic support for software
queueing. It also contains some knobs that will be
patched later.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

This merely adds some parsing, generation and
sanity checks with placeholders for real
code/functionality to be added later.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

The pull-push functionality of 10.4 will be based
on peer_id and tid. These will need to be mapped,
eventually, to ieee80211_txq to be used with
ieee80211_tx_dequeue().

Iterating over existing stations every time
peer_id needs to be mapped to a station would be
inefficient wrt CPU time.

The new firmware, which will be the only user of
the code flow-wise, will guarantee to use low
peer_ids first so despite peer_map's apparent huge
size d-cache thrashing should not be a problem.

Older firmware hot paths will effectively not use
peer_map.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

The 10.4.3 firmware with congestion control
guarantees that each peer has only a single
peer_id mapping.

The 1:1 mapping isn't the case for older firmwares
(e.g. 10.4.1, 10.2, 10.1) but it should not
matter. This 1:1 mapping is going to be only used
by future code which inherently (flow-wise) is for
10.4.3.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

Tx pending counter logic assumed that the sk_buff
is already known and hence was performed in HTT
functions themselves.

However, for the sake of future wake_tx_queue()
usage the driver must be able to tell whether it
can submit more frames to firmware before it
dequeues frame from ieee80211_txq (and thus long
before HTT Tx functions are called) because once a
frame is dequeued it cannot be requeud back to
mac80211.

This prepares the driver for future changes.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

Some future changes will need to determine final
tx method early on. Prepare the code.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

This prepares the code for future reuse with
ieee80211_txq and wake_tx_queue() in mind.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

Needed by the upcoming merge of iwlwifi-next-for-kalle-2016-03-02 tag.

ath.git patches for 4.6. Major changes:

ath10k

* dt: add bindings for ipq4019 wifi block
* start adding support for qca4019 chip

ath9k

* add device ID for Toshiba WLM-20U2/GN-1080
* allow more than one interface on DFS channels

Zhang Shengju says:

====================
use reset to set header pointers

This patch series replace set function with reset when offset is zero.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Since offset is zero, it's not necessary to use set function. Reset
function is straightforward, and will remove the unnecessary add
operation in set function.
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since offset is zero, it's not necessary to use set function. Reset
function is straightforward, and will remove the unnecessary add
operation in set function.
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since offset is zero, it's not necessary to use set function. Reset
function is straightforward, and will remove the unnecessary add
operation in set function.
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since offset is zero, it's not necessary to use set function. Reset
function is straightforward, and will remove the unnecessary add operation
in set function.
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'rxrpc-rewrite-20160304' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

David Howells says:

====================
RxRPC: Rewrite part 1

Here's the first set of patches from my RxRPC rewrite, aimed at net-next.
These do some clean ups and bug fixes.  Most of the changes are small, but
there are a couple of bigger changes:

 (*) Convert call flag numbers and event numbers into enums.  Then rename
     the event numbers to all have _EV_ in their name to stop confusion.
     Fix one instance of an event bit being used instead of a flag bit.

 (*) A copy of the Rx protocol header is kept in the sk_buff private data.
     Keep this in host byte order rather than network byte order as it
     makes more sense.  A number of other fields then get converted into
     host byte order too.

     Conversion between host and network byte order is then done at the
     packet reception/generation stage.

This is based on net-next/master
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Nicolas Dichtel says:

====================
uapi: consolidate DIV_ROUND_UP definition

The inital goal was to consolidate ethtool.h uapi header. But I took the
opportunity to remove all duplicate definitions of DIV_ROUND_UP.

v3: add patch #2 and #3

v2: split the patch
    define DIV_ROUND_UP in uapi
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

INT_MAX needs limits.h in userland.
When ethtool.h is included by a userland app, we got the following error:

.../usr/include/linux/ethtool.h: In function 'ethtool_validate_speed':
.../usr/include/linux/ethtool.h:1471:18: error: 'INT_MAX' undeclared (first use in this function)
  return speed <= INT_MAX || speed == SPEED_UNKNOWN
                  ^

Fixes: e02564ee ("ethtool: make validate_speed accept all speeds between 0 and INT_MAX")
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Let's use __KERNEL_DIV_ROUND_UP, which is defined in uapi/linux/kernel.h.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

let's use the common definition to avoid the following warning during the
compilation:

drivers/scsi/cxgbi/cxgb4i/cxgb4i.c:161:0: warning: "DIV_ROUND_UP" redefined
 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 ^
In file included from include/linux/list.h:8:0,
                 from include/linux/module.h:9,
                 from drivers/scsi/cxgbi/cxgb4i/cxgb4i.c:16:
include/linux/kernel.h:67:0: note: this is the location of the previous definition
 #define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP
 ^
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

DIV_ROUND_UP is defined in linux/kernel.h only for the kernel.
When ethtool.h is included by a userland app, we got the following error:

include/linux/ethtool.h:1218:8: error: variably modified 'queue_mask' at file scope
  __u32 queue_mask[DIV_ROUND_UP(MAX_NUM_QUEUE, 32)];
        ^

Let's add a common definition in uapi and use it everywhere.

Fixes: ac2c7ad0 ("net/ethtool: introduce a new ioctl for per queue setting")
CC: Kan Liang <kan.liang@intel.com>
Suggested-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rolf is no longer in his previous role at Netronome and as far as I know no
longer working on the NFP driver. Thus it does not seem appropriate for him
to be a co-maintainer anymore.
Reviewed-by: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the ICMP message processing code, don't try to map ICMP codes to UNIX
error codes as the caller (IPv4/IPv6) already did that for us (ee_errno).
Signed-off-by: David Howells <dhowells@redhat.com>

Clear the unused part of a sockaddr_rxrpc structs so that memcmp() can be
used to compare them.
Signed-off-by: David Howells <dhowells@redhat.com>

Forced casts are needed to avoid sparse warning when directly comparing
be32 values.
Signed-off-by: David Howells <dhowells@redhat.com>

The version number rxkad places in the response should be network byte
order.

Whilst we're at it, rearrange the code to be more readable.
Signed-off-by: David Howells <dhowells@redhat.com>

Use ACCESS_ONCE() when accessing the other-end pointer into a circular
buffer as it's possible the other-end pointer might change whilst we're
doing this, and if we access it twice, we might get some weird things
happening.
Signed-off-by: David Howells <dhowells@redhat.com>

Remove some excess whitespace, insert some missing spaces and adjust a
couple of comments.
Signed-off-by: David Howells <dhowells@redhat.com>

Currently, received RxRPC packets outside the range 1-13 are rejected.
There are, however, holes in the range that should also be rejected - plus
at least one type we don't yet support - so reject these also.
Signed-off-by: David Howells <dhowells@redhat.com>

The upper bound of the defined range for rx_mtu is being set in the same
member as the lower bound (extra1) rather than the correct place (extra2).
I'm not entirely sure why this compiles.
Signed-off-by: David Howells <dhowells@redhat.com>

Fix the protocol family set in the proto_ops for rxrpc to be PF_RXRPC not
PF_UNIX.
Signed-off-by: David Howells <dhowells@redhat.com>

Currently, a copy of the Rx packet header is copied into the the sk_buff
private data so that we can advance the pointer into the buffer,
potentially discarding the original.  At the moment, this copy is held in
network byte order, but this means we're doing a lot of unnecessary
translations.

The reasons it was done this way are that we need the values in network
byte order occasionally and we can use the copy, slightly modified, as part
of an iov array when sending an ack or an abort packet.

However, it seems more reasonable on review that it would be better kept in
host byte order and that we make up a new header when we want to send
another packet.

To this end, rename the original header struct to rxrpc_wire_header (with
BE fields) and institute a variant called rxrpc_host_header that has host
order fields.  Change the struct in the sk_buff private data into an
rxrpc_host_header and translate the values when filling it in.

This further allows us to keep values kept in various structures in host
byte order rather than network byte order and allows removal of some fields
that are byteswapped duplicates.
Signed-off-by: David Howells <dhowells@redhat.com>

Rename call event names to begin RXRPC_CALL_EV_ to distinguish them from the
flags.
Signed-off-by: David Howells <dhowells@redhat.com>

Convert call flag and event numbers into enums and move their definitions
outside of the struct.

Also move the call state enum outside of the struct and add an extra
element to count the number of states.
Signed-off-by: David Howells <dhowells@redhat.com>

Fix a case where RXRPC_CALL_RELEASE (an event) is being used to specify a
flag bit.  RXRPC_CALL_RELEASED should be used instead.
Signed-off-by: David Howells <dhowells@redhat.com>

Some devices declare a high number of TX queues, then set a much
lower real_num_tx_queues

This cause setups using fq_codel, sfq or fq as the default qdisc to consume
more memory than really needed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrew and Ying Huang's test robot both reported usage count problems that
trace back to the 'keep address on ifdown' patch.

>From Andrew:
We execute CRIU test on linux-next. On the current linux-next kernel
they hangs on creating a network namespace.

The kernel log contains many massages like this:
[ 1036.122108] unregister_netdevice: waiting for lo to become free.
Usage count = 2
[ 1046.165156] unregister_netdevice: waiting for lo to become free.
Usage count = 2
[ 1056.210287] unregister_netdevice: waiting for lo to become free.
Usage count = 2

I tried to revert this patch and the bug disappeared.

Here is a set of commands to reproduce this bug:

[root@linux-next-test linux-next]# uname -a
Linux linux-next-test 4.5.0-rc6-next-20160301+ #3 SMP Wed Mar 2
17:32:18 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

[root@linux-next-test ~]# unshare -n
[root@linux-next-test ~]# ip link set up dev lo
[root@linux-next-test ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
[root@linux-next-test ~]# logout
[root@linux-next-test ~]# unshare -n

 -----

The problem is a change made to RTM_DELADDR case in __ipv6_ifa_notify that
was added in an early version of the offending patch and is no longer
needed.

Fixes: f1705ec1 ("net: ipv6: Make address flushing on ifdown optional")
Cc: Andrey Wagin <avagin@gmail.com>
Cc: Ying Huang <ying.huang@linux.intel.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>