Commit Graph

120 Commits

Author SHA1 Message Date
Julian Wiedmann
a698e13728 s390/qdio: optimize state inspection of HW-owned SBALs
When get_buf_states() gets called with count > 1, it scans the
corresponding number of SBAL states until it encounters a mismatch.

But when these SBALs are in a HW-owned state, the callers don't actually
care _how many_ such SBALs are on the queue. If we can't process the
first SBAL, we can't process any of the following SBALs either. So when
the first SBAL is HW-owned, skip the scan of the remaining SBALs and
thus save some CPU time.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-08 15:01:23 +02:00
Julian Wiedmann
5a19d67027 s390/qdio: use get_buf_state() in debug_get_buf_state()
For a 1-SBAL state inspection, use the corresponding helper.
No functional change, just reducing the number of immediate callers to
get_buf_states().

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-08 15:01:23 +02:00
Julian Wiedmann
3060781f26 s390/qdio: allow to scan all Output SBALs in one go
Old code restricted the number of inspected SBALs to
QDIO_MAX_BUFFERS_PER_Q - 1, as otherwise the first_to_check and
first_to_kick cursors could overlap. Subsequent code would then assume that
there was no progress on the queue, when in fact _all_ SBALs on the queue
were ready-to-process.

This limitation no longer applies, so allow the queue-scan code to inspect
all SBALs on the queue. Note that qeth requires an additional patch
("s390/qeth: stop/wake TX queues based on their fill level"), to avoid
potential queue stalls when all 128 SBALs are reported as ready-to-process.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-08 15:01:23 +02:00
Julian Wiedmann
6bcf74e2d1 s390/qdio: consolidate index tracking for queue scan
qdio.ko offers a small number of high-level functions to drive the
scanning of a QDIO queue for ready-to-process SBALs:
qdio_get_next_buffers(), __[ti]qdio_inbound_processing() and
__qdio_outbound_processing().

Let each of those functions maintain the 'start' index for their current
scan, and pass it to lower-level helpers as needed. This improves the
code's overall layering, and allows us to eliminate the additional
first_to_kick cursor with a follow-on patch.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-18 10:10:32 +02:00
Julian Wiedmann
5b2ad27052 s390/qdio: limit direct access to first_to_check cursor
Refactor all the low-level helpers to take the first_to_check cursor as
parameter, rather than accessing it directly.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-18 10:10:31 +02:00
Julian Wiedmann
dccbbaff17 s390/qdio: eliminate queue's last_move cursor
This cursor is used for debugging only. But since
commit "s390/qdio: pass up count of ready-to-process SBALs" it effectively
duplicates the first_to_check cursor, diverging for just a short moment
when get_*_buffer_frontier() updates q->first_to_check.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:26 +02:00
Julian Wiedmann
65e4f77638 s390/qdio: simplify SBAL range calculation
When passing a range of ready-to-process SBALs to the upper-layer
driver, use the available 'count' instead of calculating the distance
between the first_to_check and first_to_kick cursors.

This simplifies the logic of the queue-scan path, and opens up the
possibility of scanning all 128 SBALs in one go (as determining the
reported count no longer requires wrap-around safe arithmetic on the
queue's cursors).

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:25 +02:00
Julian Wiedmann
b39544c6e0 s390/qdio: pass up count of ready-to-process SBALs
When qdio_{in,out}bound_q_moved() scans a queue for pending work, it
currently only returns a boolean to its caller. The interface to the
upper-layer-drivers (qdio_kick_handler() and qdio_get_next_buffers())
then re-calculates the number of pending SBALs from the
q->first_to_check and q->first_to_kick cursors.

Refactor this so that whenever get_{in,out}bound_buffer_frontier()
adjusted the queue's first_to_check cursor, it also returns the
corresponding count of ready-to-process SBALs (and 0 else).
A subsequent patch will then make use of this additional information.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-04-10 17:47:24 +02:00
Julian Wiedmann
2f2f3839fb s390/qdio: clean up qdio_check_outbound_after_thinint()
This helper is not thinint-specific, qdio_get_next_buffers() also calls it
for non-thinint devices. So give it a more fitting name, and while at it
adjust its parameter.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-03-29 07:23:50 +01:00
Julian Wiedmann
f85b2b297c s390/qdio: clean up pci_out_supported()
pci_out_supported() currently takes a single queue as parameter, even
though Output IRQ support is a per-device feature. Adjust the parameter,
so that the macro can also be used in code paths with no access to a queue
struct. This allows us to remove the remaining open-coded checks for
QIB_AC_OUTBOUND_PCI_SUPPORTED.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-03-29 07:23:49 +01:00
Julian Wiedmann
ccc413f621 s390/qdio: clean up AOB handling
I've stumbled over this too many times now... AOBs are only ever used on
Output Queues. So in qdio_kick_handler(), move the call to their handler
into the Output-only path, and get rid of the convoluted contains_aobs()
helper. No functional change.

While at it, also remove
1. the unused sbal_state->aob field. For processing an async completion,
   upper-layer drivers get their AOB pointer from the CQ buffer.
2. an unused EXPORT for qdio_allocate_aob(). External users would have
   no way of passing an allocated AOB back into qdio.ko anyways...

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-09-20 13:20:29 +02:00
Julian Wiedmann
64e03ff726 s390/qdio: reset old sbal_state flags
When allocating a new AOB fails, handle_outbound() is still capable of
transmitting the selected buffer (just without async completion).

But if a previous transfer on this queue slot used async completion, its
sbal_state flags field is still set to QDIO_OUTBUF_STATE_FLAG_PENDING.
So when the upper layer driver sees this stale flag, it expects an async
completion that never happens.

Fix this by unconditionally clearing the flags field.

Fixes: 104ea556ee ("qdio: support asynchronous delivery of storage blocks")
Cc: <stable@vger.kernel.org> #v3.2+
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-06-25 10:14:37 +02:00
Julian Wiedmann
89286320a2 s390/qdio: clear intparm during shutdown
During shutdown, qdio returns its ccw device back to control by the
upper-layer driver. But there is a remote chance that by the time where the
IRQ handler gets switched back, the interrupt for the preceding
ccw_device_{clear,halt} hasn't been presented yet.
Upper-layer drivers would then need to handle this IRQ - and since the IO
is issued with an intparm, it could very well be confused with whatever
intparm mechanism the driver uses itself (eg intparm == request address).

So when switching over the IRQ handler, also clear the intparm and have
upper-layer drivers deal with any such delayed interrupt as if it was
unsolicited.

Suggested-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-04-10 07:38:58 +02:00
Julian Wiedmann
88bf319fc2 s390/qdio: split up CCQ handling for EQBS / SQBS
Get rid of the confusing two-stage translation in a hot path, and only
handle CCQs that we anticipate for the respective command. Any
unexpected value (such as CCQ 97 (rc == 1) for SQBS) should be
considered a severe HW/driver bug, and traced as such.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-26 16:13:02 +02:00
Julian Wiedmann
dae55b6fef s390/qdio: don't retry EQBS after CCQ 96
Immediate retry of EQBS after CCQ 96 means that we potentially misreport
the state of buffers inspected during the first EQBS call.

This occurs when
1. the first EQBS finds all inspected buffers still in the initial state
   set by the driver (ie INPUT EMPTY or OUTPUT PRIMED),
2. the EQBS terminates early with CCQ 96, and
3. by the time that the second EQBS comes around, the state of those
   previously inspected buffers has changed.

If the state reported by the second EQBS is 'driver-owned', all we know
is that the previous buffers are driver-owned now as well. But we can't
tell if they all have the same state. So for instance
- the second EQBS reports OUTPUT EMPTY, but any number of the previous
  buffers could be OUTPUT ERROR by now,
- the second EQBS reports OUTPUT ERROR, but any number of the previous
  buffers could be OUTPUT EMPTY by now.

Effectively, this can result in both over- and underreporting of errors.

If the state reported by the second EQBS is 'HW-owned', that doesn't
guarantee that the previous buffers have not been switched to
driver-owned in the mean time. So for instance
- the second EQBS reports INPUT EMPTY, but any number of the previous
  buffers could be INPUT PRIMED (or INPUT ERROR) by now.

This would result in failure to process pending work on the queue. If
it's the final check before yielding initiative, this can cause
a (temporary) queue stall due to IRQ avoidance.

Fixes: 25f269f173 ("[S390] qdio: EQBS retry after CCQ 96")
Cc: <stable@vger.kernel.org> #v3.2+
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-26 16:12:53 +02:00
Julian Wiedmann
c11a3dfd6f s390/qdio: restrict buffer merging to eligible devices
Only attempt to merge PENDING into EMPTY buffers for devices where
the PENDING state is actually expected (ie. IQD with CQ).
This might speed up the hot path a little bit.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-26 16:12:48 +02:00
Julian Wiedmann
0cf1e05157 s390/qdio: don't merge ERROR output buffers
On an Output queue, both EMPTY and PENDING buffer states imply that the
buffer is ready for completion-processing by the upper-layer drivers.

So for a non-QEBSM Output queue, get_buf_states() merges mixed
batches of PENDING and EMPTY buffers into one large batch of EMPTY
buffers. The upper-layer driver (ie. qeth) later distuingishes PENDING
from EMPTY by inspecting the slsb_state for
QDIO_OUTBUF_STATE_FLAG_PENDING.

But the merge logic in get_buf_states() contains a bug that causes us to
erronously also merge ERROR buffers into such a batch of EMPTY buffers
(ERROR is 0xaf, EMPTY is 0xa1; so ERROR & EMPTY == EMPTY).
Effectively, most outbound ERROR buffers are currently discarded
silently and processed as if they had succeeded.

Note that this affects _all_ non-QEBSM device types, not just IQD with CQ.

Fix it by explicitly spelling out the exact conditions for merging.

For extracting the "get initial state" part out of the loop, this relies
on the fact that get_buf_states() is never called with a count of 0. The
QEBSM path already strictly requires this, and the two callers with
variable 'count' make sure of it.

Fixes: 104ea556ee ("qdio: support asynchronous delivery of storage blocks")
Cc: <stable@vger.kernel.org> #v3.2+
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-26 16:12:33 +02:00
Julian Wiedmann
152485bf76 s390/qdio: simplify math in get_*_buffer_frontier()
When determining the buffer count that get_buf_states() should
be queried for, 'count' is capped at 127 buffers.
So the check
	q->first_to_check == (q->first_to_check + count) % 128
can be reduced to
	count == 0

This helps to emphasize that get_buf_states() is really only
called with count > 0.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-03-26 16:12:25 +02:00
Sebastian Ott
364e3f90f8 s390/cio: fix kernel-doc usage
Fix the kernel-doc usage in cio to get rid of (W=1) build warnings like:
drivers/s390/cio/cio.c:1068: warning: No description found for parameter 'sch'

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-02-05 07:34:52 +01:00
Julian Wiedmann
b23481fbfc s390/qdio: restrict target-full handling to IQDIO
The 'no target buffer empty' error code only applies to HiperSockets.
If this code is reported on a different queue type, be sure to make the
same amount of noise as for any other error code.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-12-05 07:51:08 +01:00
Julian Wiedmann
0b926ac304 s390/qdio: consider ERROR buffers for inbound-full condition
In the unlikely case that an ERROR buffer (presented by the HW)
consumed the last available slot on the input queue, increment the
corresponding statistics counter.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-12-05 07:51:08 +01:00
Greg Kroah-Hartman
724117b77b s390: cio: add SPDX identifiers to the remaining files
It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/s390/cio/ files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-24 14:28:41 +01:00
Kees Cook
cb9f780aa9 s390: qdio: Convert timers to use timer_setup()
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
[sebott: fixed compile error due to invalid struct member]
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2017-11-14 11:01:33 +01:00
Julian Wiedmann
f83435c42e s390/qdio: improve some debug prints
With multiple input queues, these DBFs turned out to be not
very helpful...

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-02-03 13:50:23 +01:00
Ursula Braun
9bce8b2cbe s390/qdio: avoid reschedule of outbound tasklet once killed
During qdio_shutdown the queue tasklets are killed for all inbound and
outbound queues. The queue structures might be freed after
qdio_shutdown.
Thus it must be guaranteed that these queue tasklets are not rescheduled
after that. In addition the outbound queue timers are deleted and it
must
be guaranteed that these timers are not restarted after qdio_shutdown
processing. Timer deletion should make use of del_timer_sync() to make
sure qdio_outbound_timer() is finished on other CPUs as well. Queue
tasklets should be scheduled in state QDIO_IRQ_STATE_ACTIVE only.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-08 16:01:28 +02:00
Sebastian Ott
6e30c549f6 s390/qdio: remove checks for ccw device internal state
Prior to starting IO qdio checks for the internal state of the ccw
device. These checks happen without locking, so consistency between
state evaluation and starting of the IO is not guaranteed.

Since the internal state is checked during ccw_device_start it is
safe to get rid of these additional checks.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-08 15:41:34 +02:00
Sebastian Ott
ddebf6612c s390/qdio: fix double return code evaluation
qdio sometimes checks return codes twice. First with the ccw device's
lock held and then a 2nd time after the lock is released. Simplify
the code by releasing the lock earlier and unify the return code
evaluation.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-08 15:41:34 +02:00
Sebastian Ott
a48ed86715 s390/qdio: get rid of spin_lock_irqsave usage
All qdio functions that use spin_lock_irqsave are never used
from irq context. Thus it is safe to convert all of them to
use spin_lock_irq.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-08 15:41:33 +02:00
Sebastian Ott
9080c92494 s390/qdio: obtain subchannel_id via ccw_device_get_schid()
We want to get rid of the copy of struct subchannel_id maintained in
ccw_device_private, so obtain it using ccw_device_get_schid().

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-08-08 15:41:33 +02:00
Eugene Crosser
ec6674c638 s390/qdio: fix WARN_ON_ONCE condition
If HiperSockets Completion Queueing is enabled, qdio always
issues a warning, since the condition is always met.
This patch fixes the condition in WARN_ON_ONCE that was always
true.

Signed-off-by: Eugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-07 04:52:06 -07:00
Stefan Raspl
613c4e0459 qdio: Keep device-specific dbf entries
Keep the per-device dbf entries until module is removed, with
proper error checking for debug feature setup.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-06-16 10:31:58 +02:00
Fabian Frederick
92bdae5d9c s390/qdio: replace shift loop by ilog2
account_sbals is called by get_inbound_buffer_frontier and
get_outbound_buffer_frontier with 'count' value > 0 so we can safely
convert shift loop to ilog2.

Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-06-10 10:48:28 +02:00
Ursula Braun
0f308f4f9e s390/qdio: correct program-controlled interruption checking
Get rid of compile warning in qdio_int_handler_pci() when checking
for program-controlled interruption on outbound queues.

Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-01-29 09:07:50 +01:00
Eugene Crosser
1c59a861d6 s390/qdio: bridgeport support - CHSC part
Introduce function for the "Perform network-subchannel operation"
CHSC command with operation code "bridgeport information",
and bit definitions for "characteristics" pertaning to this command.

Signed-off-by: Eugene Crosser <eugene.crosser@ru.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-01-14 15:16:09 +01:00
Heiko Carstens
eddf0d5b31 s390/qdio: fix atomic_sub() misusage
get_inbound_buffer_frontier() makes use of the return value of atomic_sub()
which shouldn't work, since atomic_sub() is supposed to return void.
This only works on s390 because atomic_sub() gets mapped to atomic_sub_return()
with a define without changing it's return value to void.

So use atomic_sub_return() instead of atomic_sub() in qeth code before fixing
atomic ops.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24 17:16:50 +02:00
Martin Schwidefsky
8c071b0f19 s390/time: correct use of store clock fast
The result of the store-clock-fast (STCKF) instruction is a bit fuzzy.
It can happen that the value stored on one CPU is smaller than the value
stored on another CPU, although the order of the stores is the other
way around. This can cause deltas of get_tod_clock() values to become
negative when they should not be.

We need to be more careful with store-clock-fast, this patch partially
reverts git commit e4b7b4238e666682555461fa52eecd74652f36bb "time:
always use stckf instead of stck if available". The get_tod_clock()
function now uses the store-clock-extended (STCKE) instruction.
get_tod_clock_fast() can be used if the fuzziness of store-clock-fast
is acceptable e.g. for wait loops local to a CPU.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-22 09:16:40 +02:00
Sebastian Ott
dae7fd4296 s390/qdio: remove unused variable
Fix a "set but not used" warning found via make W=1.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-07-16 12:21:57 +02:00
Sebastian Ott
1d46d33125 s390/qdio: remove unused function
Remove the unused function qdio_trace_aob.

Acked-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-06-26 21:10:00 +02:00
Stefan Raspl
aa2383f815 qdio: remove unused parameters
Remove unused function parameters.

Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-02-28 09:37:12 +01:00
Heiko Carstens
1aae0560d1 s390/time: rename tod clock access functions
Fix name clash with some common code device drivers and add "tod"
to all tod clock access function names.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-02-14 15:55:10 +01:00
Jan Glauber
ce1d801462 s390/qdio: rework BUG's and WARN_ON's
Remove or replace BUG/BUG_ON where possible and convert WARN_ON
to WARN_ON_ONCE if they can occur freqeuently as pointed out by:
https://lkml.org/lkml/2012/9/27/461

Checks have been removed if:
- the error condition leads to a hardware error which gets logged
  and in most cases stops the device
- the error condition is a null pointer access
- the error condition is just pointless or already handled at
  another location

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-11-23 11:14:27 +01:00
Heiko Carstens
a53c8fab3f s390/comments: unify copyright messages and remove file names
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00
Heiko Carstens
473e66baad s390/time: always use stckf instead of stck if available
The store clock fast instruction saves a couple of instructions compared
to the store clock instruction. Always use stckf instead of stck if it
is available.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16 14:42:41 +02:00
Jan Glauber
1549d13f4c s390/qdio: Cleanup error handling to drivers
Various improvements of qdio error reporting to the
upper-layer drivers (qeth, zfcp):

- Split QDIO_ERROR_ACTIVATE_CHECK_CONDITION into:

  QDIO_ERROR_ACTIVATE: qdio termination interrupt
  QDIO_ERROR_GET_BUF_STATE: QIOASSIST eqbs error
  QDIO_ERROR_SET_BUF_STATE: QIOASSIST sqbs error

  Add QDIO_ERROR_FATAL / QDIO_ERROR_TEMPORARY masks
  to ease recovery decision in upper-layer drivers.

- Don't (ab-)use qdio handler errors as return codes
  for do_QDIO but use standard error codes:

  -ENOBUFS: temporary target CC=2 condition
  -EBUSY: unresolved SIGA-W CC=2 busy condition
  -EIO: I/O error (CC=1, CC=3)

- Remove unneeded memory clobber from SIGA-R
- Remove EX_TABLE entry on SIGA-W, we want to see these errors

Reviewed-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16 14:42:36 +02:00
Jan Glauber
61d84979ab [S390] qdio: log all adapter characteristics
Log all adapter characteristics in the s390dbf to ease debugging of
new features.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Reported-by: Raymond Higgs <rayhiggs@us.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-23 11:13:24 +01:00
Michael Holzheu
3ab121ab18 [S390] kernel: Add z/VM LGR detection
Currently the following mechanisms are available to move active
Linux on System z instances between machines:
* z/VM 6.2 SSI (Single System Image)
* Suspend/resume
For moving Linux instances in this patch the term LGR (Linux Guest
Relocation) is used. Because such an operation is critical, it
should be detectable from Linux. With this patch for both, a live
system and a kernel dump, the information about LGRs is accessible.
To identify a guest, stsi and stfle data is used. A new function
lgr_info_log() compares the current data (lgr_info_cur) with the
last recorded one (lgr_info_last). In case the two data sets differ,
lgr_info_cur is logged to the "lgr" s390dbf.

The following trigger points call lgr_info_log():
* panic
* die
* kdump
* LGR timer
* PSW restart
* QDIO recovery
* resume

This patch also changes the s390dbf hex_ascii view. Now only printable ASCII
characters are shown.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11 11:59:29 -04:00
Steffen Maier
7b3cc67d44 [S390] qdio: fix handler function arguments for zfcp data router
Git commit 25f269f173 "[S390] qdio: EQBS retry after CCQ 96"
introduced a regression in regard to the zfcp data router.
Revoke the incorrect simplification of the function call arguments
for the qdio handler to make the zfcp hardware data router working
again.

This is applicable to 3.2+ kernels.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Reviewed-by: Jan Glauber <jang@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-02 17:33:00 +01:00
Jan Glauber
5f4026f8b2 [S390] qdio: prevent dsci access without adapter interrupts
A kernel panic may occur during sending or receiving network packets
on a machine without adapter interrupts since commit d36deae.
The bug is triggered by writing to the shared indicator address which
is set to 0 if the machine doesn't have adapter interrupts.

Make the reading and setting of the shared indicator dependent on the
adapter interrupt feature and while at it move the code to the
file containing the adapter interrupt related code.

Thanks to Jan Jaeger for tracking this down.

Reported-by: Jan Jaeger <jan.jaeger@westnet.com.au>
Tested-by: Jan Jaeger <jan.jaeger@westnet.com.au>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30 15:16:47 +01:00
Martin Schwidefsky
c4736d9682 [S390] sparse: fix sparse static warnings
Make functions and data static to avoid sparse warnings.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30 15:16:46 +01:00
Jan Glauber
6ffed94ea7 [S390] qdio: remove multicast polling
The multicast poll check for the outbound queue is redundant since
3d6c76f "[S390] qdio: outbound tasklet scan threshold". Remove the check.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30 15:16:45 +01:00