Improve sk_buff tracing within AF_RXRPC by the following means:

 (1) Use an enum to note the event type rather than plain integers and use
     an array of event names rather than a big multi ?: list.

 (2) Distinguish Rx from Tx packets and account them separately.  This
     requires the call phase to be tracked so that we know what we might
     find in rxtx_buffer[].

 (3) Add a parameter to rxrpc_{new,see,get,free}_skb() to indicate the
     event type.

 (4) A pair of 'rotate' events are added to indicate packets that are about
     to be rotated out of the Rx and Tx windows.

 (5) A pair of 'lost' events are added, along with rxrpc_lose_skb() for
     packet loss injection recording.
Signed-off-by: David Howells <dhowells@redhat.com>
 

Remove _enter/_debug/_leave calls from rxrpc_recvmsg_data() of which one
uses an uninitialised variable.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to follow what recvmsg does within AF_RXRPC.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to follow the life of packets that get added to a call's
receive buffer.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to log information about ACK transmission.
Signed-off-by: David Howels <dhowells@redhat.com>

Add a tracepoint to log information from received ACK packets.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a tracepoint to follow the insertion of a packet into the transmit
buffer, its transmission and its rotation out of the buffer.
Signed-off-by: David Howells <dhowells@redhat.com>

Add a pair of tracepoints, one to track rxrpc_connection struct ref
counting and the other to track the client connection cache state.
Signed-off-by: David Howells <dhowells@redhat.com>

Add additional call tracepoint points for noting call-connected,
call-released and connection-failed events.

Also fix one tracepoint that was using an integer instead of the
corresponding enum value as the point type.
Signed-off-by: David Howells <dhowells@redhat.com>

Print a symbolic packet type name for each valid received packet in the
trace output, not just a number.
Signed-off-by: David Howells <dhowells@redhat.com>

Fix the basic transmit DATA packet content size at 1412 bytes so that they
can be arbitrarily assembled into jumbo packets.

In the future, I'm thinking of moving to keeping a jumbo packet header at
the beginning of each packet in the Tx queue and creating the packet header
on the spot when kernel_sendmsg() is invoked.  That way, jumbo packets can
be assembled on the spur of the moment for (re-)transmission.
Signed-off-by: David Howells <dhowells@redhat.com>

rxrpc_send_call_packet() should use type in both its switch-statements
rather than using pkt->whdr.type.  This might give the compiler an easier
job of uninitialised variable checking.
Signed-off-by: David Howells <dhowells@redhat.com>

Don't transmit an ACK if call->ackr_reason in unset.  There's the
possibility of a race between recvmsg() sending an ACK and the background
processing thread trying to send the same one.
Signed-off-by: David Howells <dhowells@redhat.com>

Make the retransmission algorithm use for-loops instead of do-loops and
move the counter increments into the for-statement increment slots.

Though the do-loops are slighly more efficient since there will be at least
one pass through the each loop, the counter increments are harder to get
right as the continue-statements skip them.

Without this, if there are any positive acks within the loop, the do-loop
will cycle forever because the counter increment is never done.
Signed-off-by: David Howells <dhowells@redhat.com>

The soft-ACK parser doesn't increment the pointer into the soft-ACK list,
resulting in the first ACK/NACK value being applied to all the relevant
packets in the Tx queue.  This has the potential to miss retransmissions
and cause excessive retransmissions.

Fix this by incrementing the pointer.
Signed-off-by: David Howells <dhowells@redhat.com>

If the last call on a client connection is release after the connection has
had a bunch of calls allocated but before any DATA packets are sent (so
that it's not yet marked RXRPC_CONN_EXPOSED), an assertion will happen in
rxrpc_disconnect_client_call().

	af_rxrpc: Assertion failed - 1(0x1) >= 2(0x2) is false
	------------[ cut here ]------------
	kernel BUG at ../net/rxrpc/conn_client.c:753!

This is because it's expecting the conn to have been exposed and to have 2
or more refs - but this isn't necessarily the case.

Simply remove the assertion.  This allows the conn to be moved into the
inactive state and deleted if it isn't resurrected before the final put is
called.
Signed-off-by: David Howells <dhowells@redhat.com>

Call rxrpc_release_call() on getting an error in rxrpc_new_client_call()
rather than trying to do the cleanup ourselves.  This isn't a problem,
provided we set RXRPC_CALL_HAS_USERID only if we actually add the call to
the calls tree as cleanup code fragments that would otherwise cause
problems are conditional.

Without this, we miss some of the cleanup.
Signed-off-by: David Howells <dhowells@redhat.com>

In rxrpc_put_one_client_conn(), if a connection has RXRPC_CONN_COUNTED set
on it, then it's accounted for in rxrpc_nr_client_conns and may be on
various lists - and this is cleaned up correctly.

However, if the connection doesn't have RXRPC_CONN_COUNTED set on it, then
the put routine returns rather than just skipping the extra bit of cleanup.

Fix this by making the extra bit of clean up conditional instead and always
killing off the connection.

This manifests itself as connections with a zero usage count hanging around
in /proc/net/rxrpc_conns because the connection allocated, but discarded,
due to a race with another process that set up a parallel connection, which
was then shared instead.
Signed-off-by: David Howells <dhowells@redhat.com>

Purge the queue of to_be_accepted calls on socket release.  Note that
purging sock_calls doesn't release the ref owned by to_be_accepted.

Probably the sock_calls list is redundant given a purges of the recvmsg_q,
the to_be_accepted queue and the calls tree.
Signed-off-by: David Howells <dhowells@redhat.com>

Record calls that need to be accepted using sk_acceptq_added() otherwise
the backlog counter goes negative because sk_acceptq_removed() is called.
This causes the preallocator to malfunction.

Calls that are preaccepted by AFS within the kernel aren't affected by
this.
Signed-off-by: David Howells <dhowells@redhat.com>

The code for determining the last packet in rxrpc_recvmsg_data() has been
using the RXRPC_CALL_RX_LAST flag to determine if the rx_top pointer points
to the last packet or not.  This isn't a good idea, however, as the input
code may be running simultaneously on another CPU and that sets the flag
*before* updating the top pointer.

Fix this by the following means:

 (1) Restrict the use of RXRPC_CALL_RX_LAST to the input routines only.
     There's otherwise a synchronisation problem between detecting the flag
     and checking tx_top.  This could probably be dealt with by appropriate
     application of memory barriers, but there's a simpler way.

 (2) Set RXRPC_CALL_RX_LAST after setting rx_top.

 (3) Make rxrpc_rotate_rx_window() consult the flags header field of the
     DATA packet it's about to discard to see if that was the last packet.
     Use this as the basis for ending the Rx phase.  This shouldn't be a
     problem because the recvmsg side of things is guaranteed to see the
     packets in order.

 (4) Make rxrpc_recvmsg_data() return 1 to indicate the end of the data if:

     (a) the packet it has just processed is marked as RXRPC_LAST_PACKET

     (b) the call's Rx phase has been ended.
Signed-off-by: David Howells <dhowells@redhat.com>

Check the return value of rxrpc_locate_data() in rxrpc_recvmsg_data().
Signed-off-by: David Howells <dhowells@redhat.com>

Move the check of rx_pkt_offset from rxrpc_locate_data() to the caller,
rxrpc_recvmsg_data(), so that it's more clear what's going on there.
Signed-off-by: David Howells <dhowells@redhat.com>

Remove a tab that's on a line that should otherwise be blank.
Signed-off-by: David Howells <dhowells@redhat.com>

Add CONFIG_AF_RXRPC_IPV6 and make the IPv6 support code conditional on it.
This is then made conditional on CONFIG_IPV6.

Without this, the following can be seen:

   net/built-in.o: In function `rxrpc_init_peer':
>> peer_object.c:(.text+0x18c3c8): undefined reference to `ip6_route_output_flags'
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

John Crispin says:

====================
net-next: dsa: add QCA8K support

This series is based on the AR8xxx series posted by Matthieu Olivari in may
2015. The following changes were made since then

* fixed the nitpicks from the previous review
* updated to latest API
* turned it into an mdio device
* added callbacks for fdb, bridge offloading, stp, eee, port status
* fixed several minor issues to the port setup and arp learning
* changed the namespacing as this driver to qca8k

The driver has so far only been tested on qca8337/N. It should work on other QCA
switches such as the qca8327 with minor changes.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch contains initial support for the QCA8337 switch. It
will detect a QCA8337 switch, if present and declared in the DT.

Each port will be represented through a standalone net_device interface,
as for other DSA switches. CPU can communicate with any of the ports by
setting an IP@ on ethN interface. Most of the extra callbacks of the DSA
subsystem are already supported, such as bridge offloading, stp, fdb.
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add support for the 2-bytes Qualcomm tag that gigabit switches such as
the QCA8337/N might insert when receiving packets, or that we need
to insert while targeting specific switch ports. The tag is inserted
directly behind the ethernet header.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: John Crispin <john@phrozen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add device-tree binding for ar8xxx switch families.

Cc: devicetree@vger.kernel.org
Signed-off-by: John Crispin <john@phrozen.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove .owner field if calls are used which set it automatically.

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove including <linux/version.h> that don't need it.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes the following sparse warning:

drivers/net/dsa/bcm_sf2.c:963:19: warning:
 symbol 'bcm_sf2_io_ops' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When skb replaces another one in ooo queue, I forgot to also
update tp->ooo_last_skb as well, if the replaced skb was the last one
in the queue.

To fix this, we simply can re-use the code that runs after an insertion,
trying to merge skbs at the right of current skb.

This not only fixes the bug, but also remove all small skbs that might
be a subset of the new one.

Example:

We receive segments 2001:3001,  4001:5001

Then we receive 2001:8001 : We should replace 2001:3001 with the big
skb, but also remove 4001:50001 from the queue to save space.

packetdrill test demonstrating the bug

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0

+0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>
+0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
+0.100 < . 1:1(0) ack 1 win 1024
+0 accept(3, ..., ...) = 4

+0.01 < . 1001:2001(1000) ack 1 win 1024
+0    > . 1:1(0) ack 1 <nop,nop, sack 1001:2001>

+0.01 < . 1001:3001(2000) ack 1 win 1024
+0    > . 1:1(0) ack 1 <nop,nop, sack 1001:2001 1001:3001>

Fixes: 9f5afeae ("tcp: use an RB tree for ooo receive queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Yuchung Cheng <ycheng@google.com>
Cc: Yaogong Wang <wygivan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sean Wang says:

====================
mediatek: add enhancement into the existing reset flow

Current driver only resets DMA used by descriptor rings which
can't guarantee it can recover all various kinds of fatal
errors, so the patch
1) tries to reset the underlying hardware resource from scratch on
Mediatek SoC required for ethernet running.
2) refactors code in order to the reusability of existing code.
3) considers handling for race condition between the reset flow and
callbacks registered into core driver called about hardware accessing.
4) introduces power domain usage to hardware setup which leads to have
cleanly and completely restore to the state as the initial.

Changes since v1:
- fix the build error with module built causing undefined symbol for
  pinctrl_bind_pins, so using pinctrl_select_state instead accomplishes
  the pin mux setup during the reset process.
====================
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

add the protection of the race condition between
the reset process and hardware access happening
on the related callbacks.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

struct mtk_eth has already contained struct regmap ethsys pointer
to the address range of the internal circuit reset, so we reuse it
to reset more internal blocks on ethernet hardware such as packet
processing engine (PPE) and frame engine (FE) instead of rstc which
deals with FE only.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1) original driver only resets DMA used by descriptor rings
which can't guarantee it can recover all various kinds of fatal
errors, so the patch tries to reset the underlying hardware
resource from scratch on Mediatek SoC required for ethernet
running, including power, pin mux control, clock and internal
circuits on the ethernet in order to restore into the initial
state which the rebooted machine gives.

2) add state variable inside structure mtk_eth to help distinguish
mtk_hw_init is called between the initialization during boot time
or re-initialization during the reset process.

3) add ge_mode variable inside structure mtk_mac for restoring
the interface mode of the current setup for the target MAC.

4) remove __init attribute from mtk_hw_init definition
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

introduce power domain control which the digital circuit of
the ethernet belongs to inside the flow of hardware initialization
and deinitialization which helps the entire ethernet hardware block
could restart cleanly and completely as being back to the initial
state when the whole machine reboot.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This cleans up the error path inside mtk_hw_init call, causing it able
to exit appropriately when something fails and also includes refactoring
mtk_cleanup call to make the partial logic reusable on the error path.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>