linux-stable.git/drivers/s390/net, branch linux-4.1.y

s390/qeth: on channel error, reject further cmd requests

2018-05-23T01:33:55+00:00

[ Upstream commit a6c3d93963e4b333c764fde69802c3ea9eaa9d5c ]

When the IRQ handler determines that one of the cmd IO channels has
failed and schedules recovery, block any further cmd requests from
being submitted. The request would inevitably stall, and prevent the
recovery from making progress until the request times out.

This sort of error was observed after Live Guest Relocation, where
the pending IO on the READ channel intentionally gets terminated to
kick-start recovery. Simultaneously the guest executed SIOCETHTOOL,
triggering qeth to issue a QUERY CARD INFO command. The command
then stalled in the inoperabel WRITE channel.

Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: lock read device while queueing next buffer

2018-05-23T01:33:55+00:00

[ Upstream commit 17bf8c9b3d499d5168537c98b61eb7a1fcbca6c2 ]

For calling ccw_device_start(), issue_next_read() needs to hold the
device's ccwlock.
This is satisfied for the IRQ handler path (where qeth_irq() gets called
under the ccwlock), but we need explicit locking for the initial call by
the MPC initialization.

Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: when thread completes, wake up all waiters

2018-05-23T01:33:55+00:00

[ Upstream commit 1063e432bb45be209427ed3f1ca3908e4aa3c7d7 ]

qeth_wait_for_threads() is potentially called by multiple users, make
sure to notify all of them after qeth_clear_thread_running_bit()
adjusted the thread_running_mask. With no timeout, callers would
otherwise stall.

Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: free netdevice when removing a card

2018-05-23T01:33:54+00:00

[ Upstream commit 6be687395b3124f002a653c1a50b3260222b3cd7 ]

On removal, a qeth card's netdevice is currently not properly freed
because the call chain looks as follows:

qeth_core_remove_device(card)
	lx_remove_device(card)
		unregister_netdev(card->dev)
		card->dev = NULL			!!!
	qeth_core_free_card(card)
		if (card->dev)				!!!
			free_netdev(card->dev)

Fix it by free'ing the netdev straight after unregistering. This also
fixes the sysfs-driven layer switch case (qeth_dev_layer2_store()),
where the need to free the current netdevice was not considered at all.

Note that free_netdev() takes care of the netif_napi_del() for us too.

Fixes: 4a71df50047f ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann 
Reviewed-by: Ursula Braun 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: fix IPA command submission race

2018-03-21T03:49:49+00:00

[ Upstream commit d22ffb5a712f9211ffd104c38fc17cbfb1b5e2b0 ]

If multiple IPA commands are build & sent out concurrently,
fill_ipacmd_header() may assign a seqno value to a command that's
different from what send_control_data() later assigns to this command's
reply.
This is due to other commands passing through send_control_data(),
and incrementing card->seqno.ipa along the way.

So one IPA command has no reply that's waiting for its seqno, while some
other IPA command has multiple reply objects waiting for it.
Only one of those waiting replies wins, and the other(s) times out and
triggers a recovery via send_ipa_cmd().

Fix this by making sure that the same seqno value is assigned to
a command and its reply object.
Do so immediately before submitting the command & while holding the
irq_pending "lock", to produce nicely ascending seqnos.

As a side effect, *all* IPA commands now use a reply object that's
waiting for its actual seqno. Previously, early IPA commands that were
submitted while the card was still DOWN used the "catch-all" IDX seqno.

Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: fix SETIP command handling

2018-03-21T03:49:49+00:00

[ Upstream commit 1c5b2216fbb973a9410e0b06389740b5c1289171 ]

send_control_data() applies some special handling to SETIP v4 IPA
commands. But current code parses *all* command types for the SETIP
command code. Limit the command code check to IPA commands.

Fixes: 5b54e16f1a54 ("qeth: do not spin for SETIP ip assist command")
Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: no ETH header for outbound AF_IUCV

2018-03-01T00:32:14+00:00

[ Upstream commit acd9776b5c45ef02d1a210969a6fcc058afb76e3 ]

With AF_IUCV traffic, the skb passed to hard_start_xmit() has a 14 byte
slot at skb->data, intended for an ETH header. qeth_l3_fill_af_iucv_hdr()
fills this ETH header... and then immediately moves it to the
skb's headroom, where it disappears and is never seen again.

But it's still possible for us to return NETDEV_TX_BUSY after the skb has
been modified. Since we didn't get a private copy of the skb, the next
time the skb is delivered to hard_start_xmit() it no longer has the
expected layout (we moved the ETH header to the headroom, so skb->data
now starts at the IUCV_TRANS header). So when qeth_l3_fill_af_iucv_hdr()
does another round of rebuilding, the resulting qeth header ends up
all wrong. On transmission, the buffer is then rejected by
the HiperSockets device with SBALF15 = x'04'.
When this error is passed back to af_iucv as TX_NOTIFY_UNREACHABLE, it
tears down the offending socket.

As the ETH header for AF_IUCV serves no purpose, just align the code to
what we do for IP traffic on L3 HiperSockets: keep the ETH header at
skb->data, and pass down data_offset = ETH_HLEN to qeth_fill_buffer().
When mapping the payload into the SBAL elements, the ETH header is then
stripped off. This avoids the skb manipulations in
qeth_l3_fill_af_iucv_hdr(), and any buffer re-entering hard_start_xmit()
after NETDEV_TX_BUSY is now processed properly.

Signed-off-by: Julian Wiedmann 
Signed-off-by: Ursula Braun 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: issue STARTLAN as first IPA command

2017-12-07T02:19:59+00:00

[ Upstream commit 1034051045d125579ab1e8fcd5a724eeb0e70149 ]

STARTLAN needs to be the first IPA command after MPC initialization
completes.
So move the qeth_send_startlan() call from the layer disciplines
into the core path, right after the MPC handshake.
While at it, replace the magic LAN OFFLINE return code
with the existing enum.

Signed-off-by: Julian Wiedmann 
Reviewed-by: Thomas Richter 
Reviewed-by: Ursula Braun 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: avoid null pointer dereference on OSN

2017-06-25T03:05:16+00:00

[ Upstream commit 25e2c341e7818a394da9abc403716278ee646014 ]

Access card->dev only after checking whether's its valid.

Signed-off-by: Julian Wiedmann 
Reviewed-by: Ursula Braun 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

s390/qeth: unbreak OSM and OSN support

2017-06-25T03:05:10+00:00

[ Upstream commit 2d2ebb3ed0c6acfb014f98e427298673a5d07b82 ]

commit b4d72c08b358 ("qeth: bridgeport support - basic control")
broke the support for OSM and OSN devices as follows:

As OSM and OSN are L2 only, qeth_core_probe_device() does an early
setup by loading the l2 discipline and calling qeth_l2_probe_device().
In this context, adding the l2-specific bridgeport sysfs attributes
via qeth_l2_create_device_attributes() hits a BUG_ON in fs/sysfs/group.c,
since the basic sysfs infrastructure for the device hasn't been
established yet.

Note that OSN actually has its own unique sysfs attributes
(qeth_osn_devtype), so the additional attributes shouldn't be created
at all.
For OSM, add a new qeth_l2_devtype that contains all the common
and l2-specific sysfs attributes.
When qeth_core_probe_device() does early setup for OSM or OSN, assign
the corresponding devtype so that the ccwgroup probe code creates the
full set of sysfs attributes.
This allows us to skip qeth_l2_create_device_attributes() in case
of an early setup.

Any device that can't do early setup will initially have only the
generic sysfs attributes, and when it's probed later
qeth_l2_probe_device() adds the l2-specific attributes.

If an early-setup device is removed (by calling ccwgroup_ungroup()),
device_unregister() will - using the devtype - delete the
l2-specific attributes before qeth_l2_remove_device() is called.
So make sure to not remove them twice.

What complicates the issue is that qeth_l2_probe_device() and
qeth_l2_remove_device() is also called on a device when its
layer2 attribute changes (ie. its layer mode is switched).
For early-setup devices this wouldn't work properly - we wouldn't
remove the l2-specific attributes when switching to L3.
But switching the layer mode doesn't actually make any sense;
we already decided that the device can only operate in L2!
So just refuse to switch the layer mode on such devices. Note that
OSN doesn't have a layer2 attribute, so we only need to special-case
OSM.

Based on an initial patch by Ursula Braun.

Fixes: b4d72c08b358 ("qeth: bridgeport support - basic control")
Signed-off-by: Julian Wiedmann 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin