Introduce BACK establishment procedures; decision logic is not implemented
yet; debugfs entry 'addba' used to manually trigger addba/delba for ringid 0.

debugfs usage:
to establish BACK with agg_wsize 16:
  echo 16 > /sys/kernel/debug/ieee80211/phy0/wil6210/addba
to delete BACK:
  echo 0 > /sys/kernel/debug/ieee80211/phy0/wil6210/addba
to change agg_wsize, one need to delete BACK and establish it anew

ADDBA flow for:

- originator

Tx side (initiator) sends WMI_VRING_BA_EN_CMDID providing
agg_wsize and timeout parameters.
Eventually, it gets event confirming BACK agreement - WMI_BA_STATUS_EVENTID
with negotiated parameters. On this event, update Tx vring data
(struct vring_tx_data) and display BACK parameters on debugfs

- recipient

Rx side (recipient) firmware informs driver about ADDBA with
WMI_RCP_ADDBA_REQ_EVENTID, driver process it in service work
queue wq_service. It adjusts parameters and sends response
with WMI_RCP_ADDBA_RESP_CMDID, and final confirmation provided
by firmware with WMI_ADDBA_RESP_SENT_EVENTID. In case of success,
driver updates Rx BACK reorder buffer.

policy for BACK parameters:
- aggregation size (agg_wsize * MPDUsize)) to not exceed 64Kbytes

DELBA flow for:

- originator

driver decides to terminate BACK, it sends WMI_VRING_BA_DIS_CMDID
and updates struct vring_tx_data associated with vring; ignore
WMI_DELBA_EVENTID.

- recipient

firmware informs driver with WMI_DELBA_EVENTID,
driver deletes correspondent reorder buffer

ADDBA request processing requires sending WMI command, therefore
it is processed in work queue context. Same work queue used as for
connect, it get renamed to wq_service
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>

Hardware doesn't place any restrictions on the buffer alignment,
consider this TODO resolved.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

In the wil_tx_ring, error message printed when tx attempted
while vring has no space to accommodate all fragments of frame.
Normally, such situation handled by stopping tx queue.
But, if tx queue is by-passed (like pktgen does), this error
will be triggered at high rate and dmesg will be flooded with
this message. Whole system may become unstable and hang with
no possible recover except power cycle.

Rate-limit it to prevent dmesg flooding.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Allow to configure VRING size for both Rx and Tx via module parameters:
rx_ring_order and tx_ring_order. Parameters are ring size orders, i.e.
ring size calculated as 1 << order.
Defaults for both Tx and Rx are order 9, i.e. size 512
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

It is possible to configure driver using mtu_max module parameter
by setting it to value in range of 68..7920 inclusive.
This is sub-optimal performance-wise in case packet is larger than 1 page.
mtu_max default value is 2228.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

HW supports upto 2304 packet size on the air.
HW is responsible for adding (Tx) or removing (Rx) the following headers:
802.11 hdr: 26B
SNAP: 8B
CRC: 4B
Security (optional): 24B
HW adds max 62B to the payload passed from driver. It means driver can use
max packet size of 2304-62 = 2242B
Signed-off-by: NDedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

added misc printouts in some init/uninit functions for better traceability
Signed-off-by: NDedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

- parentheses, indentation, typos
- seq_puts() instead of seq_printf() with single argument
- sizeof(var) vs. sizeof(type)
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When reading 'bf' file on debugfs, query beam forming status from firmware.
Ignore CID's that return error or return all zeros.

Remove obsolete code that used to maintain statistics on per-device basis,
as now it is reported be per-CID and current.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Fix Copyright headers in all files changed in 2014, to mention 2014
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Variable 'ctx' declarad again in the inner loop. Should use
one from outer loop instead.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Provide both event (netif_tx_[stop|wake]) tracking via printk;
and state via debugfs 'info'
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

On Tx path, when vring for the destination not found,
it was considered as error and message was printed unconditionally.
However, this situation is normal after disconnect. If disconnect was while
heavy traffic load, lots of Tx packets will be dropped and this would
cause significant amount of prints in dmesg.
Demote messages priority from 'error' to 'debug'.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

For performance monitoring, trace time intervals when Tx vring
is idle/not idle. Use CPU cycle counter for this, because jiffies is
too rough, and other precise time measurement methods involve
overhead while get_cycles() should be fast.
This used to provide some estimation for percentage when Tx vring
was idle, i.e. when hardware is under-utilized.
Estimation is not precise because of many reasons - CPU frequency scaling,
grt_cycles() may be per core etc. But still, it is good estimation
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

print used/available counters on debugfs;
print to dmesg when Tx vring becomes empty

This aids with performance investigation
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

use proper format %pad for the dma_addr_t arguments;
prefix %p with 0x, as %p don't print is by itself
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Provide clear definition of the watermarks for the vring descriptor space.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When disconnecting some CID, corresponded Tx vring get released. During vring
release, all descriptors get freed. It is possible that Tx NAPI working on the same
vring simultaneously. If it happens, descriptor may be double freed.

To protect from the race above, make sure NAPI won't process the same vring.
Introduce 'enabled' flag in the struct vring_tx_data. Proceed with Tx NAPI only if
'enabled' flag set. Prior to Tx vring release, clear this flag and make sure NAPI
get synchronized.

NAPI enablement status protected by wil->mutex, add protection where it was
missing and check for it.

During reset, disconnect all peers first, then proceed with the Rx vring. It allows for
the disconnect flow to observe proper 'wil->status' and correctly notify cfg80211 about
connection status change
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

GRO is easy to enable when already using NAPI framework,
and it improves CPU utilisation. Enable it by default.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When switching between STA and AP modes, memory allocated for Rx vring leaks
This is because start_ap() allocates Rx vring but stop_ap() do not free it.
Logically, Rx vring is not valid (HW can't use it anymore), so free it in reset()
Also, check double init for Rx vring and bail out with -EINVAL
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When FW crashes, dmesg get polluted with the "FW not ready"
error message. Print it only once per FW lifecycle
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Introduce enum to describe mapping type; allow 'none' in addition to
'single' and 'page'; this is preparation for GSO
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When setting fragmented skb for Tx, assign skb to the last descriptor
and set number of fragments in the 1-st one
On Tx complete, HW sets "DU" bit in Tx descriptor only for the last
descriptor; so search for it using number of fragments field.
Middle descriptors may have "DU" bit not set by the hardware.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When connection established, as reported by WMI_CONNECT_EVENTID,
4-way handshaking required for the secure connection is not done
yet. It is indicated by another WMI event. Wait for it and only then
allow data traffic. In case of non-secure connection, FW reports
"data port open" immediately after connection.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Encode/decode helpers
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Groupcast frames are not subject for BACK reordering because they are not
ACK'ed and one can't request re-transmitt
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Need to fill translation table before calling WMI with WMI_VRING_CFG_CMDID
since firmware may generate events during this call; and events need translation
table filled to be properly dispatched
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Calculate statistics per connection, report with "iw station dump"
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Hardware do not support "real" broadcast on the air.
Use method similar to the Directed Multicast Service (DMS) as
described in the 10.23.15.2 "DMS procedures"

This service copies frame and delivers unicast for each associated peer

Do the following: send original frame to 1-st Tx vring, and send copies
to all other active vrings.

As currently hardware/firmware don't support A-MSDU, convert broadcast
frame to unicast instead of wrapping it in A-MSDU
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When running multiple connections, hardware can't do BACK reordering
and it should be done on the host.

Model after mac80211's implementation. Drop RCU for now;
to be re-added when BACK will be stabilized

BACK handshaking is not implemented yet in the hardware,
pretend it was done to support the way FW operating
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Enable multiple (up to 8 - HW/FW limitation) simultaneous connections.
Each connection has its own CID (connection ID) that describes chip's
beam-forming entity. Tx Vring should refer to correct CID for frame to reach
its destination.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

This fixes bug found by the kbuild test robot:

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next.git master
head:   1e2f9295
commit: 1cbbcb08 [135/140] wil6210: prefetch head of packet
config: make ARCH=microblaze allyesconfig

All error/warnings:

   drivers/net/wireless/ath/wil6210/txrx.c: In function 'wil_vring_reap_rx':
>> drivers/net/wireless/ath/wil6210/txrx.c:381:2: error: implicit declaration of function 'prefetch' [-Werror=implicit-function-declaration]
     prefetch(skb->data);
     ^
   cc1: some warnings being treated as errors

vim +/prefetch +381 drivers/net/wireless/ath/wil6210/txrx.c

   375                  wil_err(wil, "Rx size too large: %d bytes!\n", dmalen);
   376                  kfree_skb(skb);
   377                  return NULL;
   378          }
   379          skb_trim(skb, dmalen);
   380
 > 381          prefetch(skb->data);
   382
   383          wil_hex_dump_txrx("Rx ", DUMP_PREFIX_OFFSET, 16, 1,
   384                            skb->data, skb_headlen(skb), false);
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As soon as skb is ready to be reaped, prefetch 1-st cache line.
This accelerates data access that is performed later, during the
packet classification by the driver and IP stack.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Bit DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS should be set for IPv4
only. Don't set it for IPv6
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Fix for TCP iperf from Windows to Linux stall after about 1sec

Hardware reports false errors in some situations:

Microsoft IP stack, in violation of RFC 1624, set TCP checksum that should be 0x0
as 0xffff. hardware report Rx csum error. If HW csum absolutely trusted,
this frame can be never received, as re-transmitted one will have same csum problem.
In addition, it mess up block ack reorder buffer, as if packet dropped, it is not score boarded
there.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add support for TCP and UDP HW checksum offloading.
RX chain is allways configured for offload mode.
In case of checksum error in RX path the DMA L4 error bit(5)
will be set to 1 and driver will drop the packet.
TX checksum offloading is configrable (ethtool -K).
TX descriptors are configured for checksum offload according
to the SKB protocol type (TCP/UDP, IPV4/6), Upon mismatch drop
the TX packet (checksum required but not TCP/UDP IPV4/6 type).
Signed-off-by: NKirshenbaum Erez <erezk@wilocity.com>
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Release fragments in the order of allocation; including one for skb head
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Finish all SW context modifications prior to notifying hardware

It used to be race condition: if HW finish Tx and issue Tx completion IRQ very fast,
prior to SW context update in wil_tx_vring, Tx completion will mis-handle descriptor, as
SW part will have no skb pointer stored.
Signed-off-by: NVladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>