i40e: Fix for recent kernel panic

Whenever we get a Tx hang we issue a PFR, which means we send AQ
messages to VFS about the reset coming. Unfortunately with the recent
fix to be able to send messages to all VFS which earlier was not
happening at all we now are sending messages to not just the VFS that
are up but also to VFS that are not up.  AQ complains about this and
sends us an error in ARQ called LAN overflow event for a queue. We
check if the queue belongs to a VF and if it does we try to send a
vc_notify_vf_reset message to that VF. Well if the VF is not up/enabled
we will be entering this function with a non-active VF id. In this
function we were assuming VF struct is populated but it won't be if
the VF is not active.

Change-ID: Ic6733cda4582d3609fe6d83b2872bb2dcdc73f4a
Signed-off-by: Ashish N Shah <ashish.n.shah@intel.com>
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
i40e: Fix a few potential VF dereferences

In some functions we might be doing potential dereference
without a check. This patch puts the check in place for all these
functions. Also fix the "for loops" so that we increment VF at the
right place so that we always do it even if we are short-circuiting
the loop through continue.

Change-ID: Id4276cfb1e841031bb7b6d6790c414242f364a9f
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
i40e: fix PTP bug

The receive hang detection routine was never being run when
PTP was enabled.

Change-ID: I200f35b0f3190d31b595df89d678f4c8a2131ba0
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
net: phy: bcm7xxx: remove 28nm wildcard entry

A wildcard entry with the 32-bits OUI 0x600d8400 was added as part of
the BCM7xxx internal PHY driver, but that entry might match other PHYs
that are not covered by this driver, so let's just remove it.

Fixes: b560a58c45c6 ("net: phy: add Broadcom BCM7xxx internal PHY driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@greenl8ke.davemloft.net>
net: phy: bcm7xxx: re-advertise all supported modes out of suspend

The BCM7xxx internal Gigabit PHYs on 28nm process platforms come out
reset without any half-duplex or "hub" compatible advertised modes,
which was causing auto-negotiation issues coming out of S3
suspend/resume, we just could not establish a link with a half-duplex
only link partner.

Make sure that the resume function properly re-configures the PHY device
to advertise all supported modes.

Fixes: b560a58c45c6 ("net: phy: add Broadcom BCM7xxx internal PHY driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@greenl8ke.davemloft.net>
net: phy: bcm7xxx: remove suspend callback for 28nm PHYs

BCM7xxx internal Gigabit PHY on 28nm process do not need anything
special to be done during suspend, remove the suspend callback since it
might be harmful rather than useful. While at it, update the comment
above bcm7xxx_suspend() to reflect that it applies only to 40nm and 65nm
process PHY devices.

Fixes: b560a58c45c6 ("net: phy: add Broadcom BCM7xxx internal PHY driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@greenl8ke.davemloft.net>
Merge branch 'bcm7xxx'

Florian Fainelli says:

====================
net: phy: bcm7xxx internal PHY fixes

Here are 3 small fixes for the Broadcom BCM7xxx internal PHY targeting
suspend/resume issues.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
batman-adv: Fix parameter order of hlist_add_behind

1d023284c31a4e40a94d5bbcb7dbb7a35ee0bcbc ("list: fix order of arguments for
hlist_add_after(_rcu)") was incorrectly rebased on top of
d9124268d84a836f14a6ead54ff9d8eee4c43be5 ("batman-adv: Fix out-of-order
fragmentation support"). The parameter order change of the rebased patch was
not re-applied as expected. This causes a memory leak and can cause crashes
when out-of-order packets are received. hlist_add_behind will try to access the
uninitalized list pointers of frag_entry_new to find the previous/next entry
and may modify/read random memory locations.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/net

Jeff Kirsher says:

====================
Intel Wired LAN Driver Updates 2014-08-15

This series contains fixes to i40e only.

Anjali provides two fixes for i40e, first adds a check for non-active
VF before sending admin queue messages to the VFS.  This resolves a
potential kernel panic which would happen whenever we got a Tx hang and
there were VFS that were not up or enabled.  The second fix adds
additional checks so that we do try to access a VF that is not up or
enabled which would dereference a null pointer.

Jesse fixes a i40e PTP bug where the hang detection routine was never
being run when PTP was enabled.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
net: phy: smsc: move smsc_phy_config_init reset part in a soft_reset function

On the one hand, phy_device.c provides a generic reset function if the phy
driver does not provide a soft_reset pointer. This generic reset does not take
into account the state of the phy, with a potential failure if the phy is in
powerdown mode. On the other hand, smsc driver provides a function with both
correct reset behaviour and configuration.

This patch moves the reset part into a new smsc_phy_reset function and provides
the soft_reset pointer to have a correct reset behaviour by default.

Signed-off-by: Gwenhael Goavec-Merou <gwenhael.goavec-merou@armadeus.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dccp: Reduce noise in output and convert to ktime_t

This fixes the problem that dccp_probe output can grow quite large without
apparent benefit (many identical data points), creating huge files (up to
over one Gigabyte for a few minutes' test run) which are very hard to
post-process (in one instance it got so bad that gnuplot ate up all memory
plus swap).

The cause for the problem is that the kprobe is inserted into dccp_sendmsg(),
which can be called in a polling-mode (whenever the TX queue is full due to
congestion-control issues, EAGAIN is returned). This creates many very
similar data points, i.e. the increase of processing time does not increase
the quality/information of the probe output.

The fix is to attach the probe to a different function -- write_xmit was
chosen since it gets called continually (both via userspace and timer);
an input-path function would stop sampling as soon as the other end stops
sending feedback.

For comparison the output file sizes for the same 20 second test
run over a lossy link:
 * before / without patch:  118   Megabytes
 * after  / with patch:       1.2 Megabytes
and there was much less noise in the output.

To allow backward compatibility with scripts that people use, the now-unused
`size' field in the output has been replaced with the CCID identifier. This
also serves for future compatibility.

While at it, the update to ktime_t was also performed.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.uk>
dccp: Remove CCID-3 specific code from dccp_probe

This creates a function pointer to wrap CCID-specific code, since
CCID-specific code should not be mixed with the general DCCP code
(in particular when CCID-3 is disabled via Kconfig).

Resolving module dependencies did not work satisfactorily in the
current dccp_probe, so I created an explicit depdency by putting
the probe handler into output.c.

% modprobe -v dccp_probe
insmod /lib/modules/2.6.28/kernel/net/dccp/dccp.ko
insmod /lib/modules/2.6.28/kernel/net/dccp/dccp_probe.ko

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp: Add dccp_probe support for CCID-2

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp ccid-3: Runtime verification of timer resolution

The DCCP base time resolution is 10 microseconds (RFC 4340, 13.1 ... 13.3).

Using a timer with a lower resolution was found to trigger the following
bug warnings/problems on high-speed networks (e.g. local loopback):
 * RTT samples are rounded down to 0 if below resolution;
 * in some cases, negative RTT samples were observed;
 * the CCID-3 feedback timer complains that the feedback interval is 0,
   since the feedback interval is in the order of 1 RTT or less and RTT
   measurement rounded this down to 0;
On an Intel computer this will for instance happen when using a
boot-time parameter of "clocksource=jiffies".

The following system log messages were observed:
  11:24:00 kernel: BUG: delta (0) <= 0 at ccid3_hc_rx_send_feedback()
  11:26:12 kernel: BUG: delta (0) <= 0 at ccid3_hc_rx_send_feedback()
  11:26:30 kernel: dccp_sample_rtt: unusable RTT sample 0, using min
  11:26:30 last message repeated 5 times

This patch defines a global constant for the time resolution, adds this in
timer.c, and checks the available clock resolution at CCID-3 module load time.

When the resolution is worse than 10 microseconds:
 * module loading exits with a message "socket type not supported",
 * when compiled into the kernel, the warning message appears in the
   kernel log file, but DCCP sockets are not made available.

The following was obtained when passing
  clocksource=jiffies
as kernel parameter (HZ=300):
[ 2.973217] DCCP: clocksource too coarse (3333 usec), need 10-usec resolution

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp ccid-3: Simplified handling of TX states

Since CCIDs are only used during the established phase of a connection,
they have very little internal state; this specifically reduces to:

 * "no packet sent" if and only if s == 0, for the TX packet size s;

 * when the first packet has been sent (i.e. `s' > 0), the question is whether
   or not feedback has been received:
   - if a feedback packet is received, "feedback = yes" is set,
   - if the nofeedback timer expires,  "feedback = no"  is set.

Thus the CCID only needs to remember state about whether or not feedback
has been received. This is now implemented using a boolean flag, which is
toggled when a feedback packet arrives or the nofeedback timer expires.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp tfrc: Suppress unavoidable "below resolution" warning

In the congestion-avoidance phase a decay of p towards 0 is natural once fewer
losses are encountered. Hence the warning message "p is below resolution" is
not necessary, and thus turned into a debug message by this patch.

The TFRC_SMALLEST_P is needed since in theory p never actually reaches 0. When
no further losses are encountered, the loss interval I_0 grows in length, 
causing p to decrease towards 0, causing X_calc = s/(RTT * f(p)) to increase.

With the given minimum-resolution this congestion avoidance phase stops at some
fixed value, an approximation formula has been added to the documentation.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp tfrc: Receiver history initialisation routine

This patch
 1) separates history allocation and initialisation, to facilitate early
    loss detection (implemented by a subsequent patch);

 2) removes duplication by using the existing tfrc_rx_hist_purge() if the
    allocation fails. This is now possible, since the initialisation routine
 3) zeroes out the entire history before using it.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp tfrc: Perform early loss detection

This enables the TFRC code to begin loss detection (as soon as the module
is loaded), using the latest updates from rfc3448bis-06, 6.3.1:

 * when the first data packet(s) are lost or marked, set
 * X_target = s/(2*R) => f(p) = s/(R * X_target) = 2,
 * corresponding to a loss rate of ~ 20.64%.

The handle_loss() function is now called right at the begin of rx_packet_recv()
and thus no longer protected against duplicates: hence a call to rx_duplicate()
has been added.  Such a call makes sense now, as the previous patch initialises
the first entry with a sequence number of GSR.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp tfrc: Return type of update_i_mean is void

This changes the return type of tfrc_lh_update_i_mean() to void, since that
function returns always `false'. This is due to

 	len = dccp_delta_seqno(cur->li_seqno, DCCP_SKB_CB(skb)->dccpd_seq) + 1;

 	if (len - (s64)cur->li_length <= 0)	/* duplicate or reordered */
		return 0;

which means that update_i_mean can only increase the length of the open loss
interval I_0, and hence the value of I_tot0 (RFC 3448, 5.4). Consequently the
test `i_mean < old_i_mean' at the end of the function always evaluates to false.

There is no known way by which a loss interval can suddenly become shorter,
therefore the return type of the function is changed to void. (That is, under
the given circumstances step (3) in RFC 3448, 6.1 will not occur.)

Further changes:
----------------
 * the function is now called from tfrc_rx_handle_loss, which is equivalent
   to the previous way of calling from rx_packet_recv (it was called whenever
   there was no new or pending loss, now  it is also updated when there is
   a pending loss - this increases the accuracy a bit);
 * added a FIXME to possibly consider NDP counting as per RFC 4342 (this is
   not implemented yet).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
dccp tfrc: Let dccp_tfrc_lib do the sampling work

This migrates more TFRC-related code into the dccp_tfrc_lib:
 * sampling of the packet size `s' (which is only needed until the first
   loss interval is computed (ccid3_first_li));
 * updating the byte-counter `bytes_recvd' in between sending feedbacks.
The result is a better separation of CCID-3 specific and TFRC specific
code, which aids future integration with ECN and e.g. CCID-4.

Further changes:
----------------
 * replaced magic number of 536 with equivalent constant TCP_MSS_DEFAULT;
   (this constant is also used when no estimate for `s' is available).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>