Commit Graph

190 Commits

Author SHA1 Message Date
Julian Wiedmann e628f28793 s390/qdio: remove unneeded sanity check in qdio_do_sqbs()
All callers of set_buf_states() are already making sure that 'count'
is not 0. So don't check it an additional time.

Note that our own code also doesn't _require_ the count to be sane
(ie. we can't overrun an array or similar). So worst case HW would
simply reject the SQBS operation and report an error.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06 14:42:26 +01:00
Julian Wiedmann a60bffe536 s390/qdio: split do_QDIO()
The callers know what type of queue they want to work with. Introduce
type-specific variants to add buffers on an {Input,Output} queue, so
that we can avoid some function parameters and the de-muxing into
type-specific hot paths.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06 14:42:25 +01:00
Julian Wiedmann b44995e515 s390/qdio: split qdio_inspect_queue()
The callers know what type of queue they want to inspect. Introduce
type-specific variants to inspect an {Input,Output} queue, so that we
can avoid one function parameter and some conditional branches in the
hot paths.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06 14:42:25 +01:00
Julian Wiedmann 513251fe25 s390/qdio: clarify handler logic for qdio_handle_activate_check()
qdio_handle_activate_check() tries to re-use one of the queue-specific
handlers to report that the ACTIVATE ccw has been terminated. But the
logic to select that handler is overly complex - in practice both
qdio drivers have at least one Input Queue, so we never take the other
paths.

Make things more obvious by removing this unused code, and clearly
spelling out that we re-use the Input Handler for generic error
reporting. This also paves the way for a world without queue-specific
error handlers.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06 14:42:25 +01:00
Julian Wiedmann 0a86cdcb4c s390/qdio: clean up access to queue in qdio_handle_activate_check()
qdio_handle_activate_check() re-uses a queue-specific handler to report
that the ACTIVATE ccw has been terminated. It uses either the first
input or output queue, so we can hard-code q->nr as 0. Also don't
access the q->irq_ptr parent pointer, we already have a pointer to
the qdio_irq.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06 14:42:25 +01:00
Julian Wiedmann 718ce9e101 s390/qdio: avoid allocating the qdio_irq with GFP_DMA
The qdio_irq contains only two fields that are directly exposed to the
HW (ccw and qib). And only the ccw needs to reside in 31-bit memory. So
allocate it separately, and remove the GFP_DMA constraint from the
qdio_irq allocation.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06 14:42:24 +01:00
Julian Wiedmann bd3a025dd2 s390/qdio: improve handling of CIWs
Fetch the individual CIWs when we actually need them, rather than
fetching both of them in qdio_setup_irq() and then needing to cache
them inside the qdio_irq.

Also deal with the error when a CIW is not available, instead of
silently dropping this error condition in qdio_setup_irq()'s caller.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-12-06 14:42:24 +01:00
Julian Wiedmann 9f79b54951 s390/qdio: remove unused support for SLIB parameters
Neither of the two drivers provides any SLIB parameter data, so get rid
of the dead code.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-08-18 10:01:28 +02:00
Julian Wiedmann 87e225bfa0 s390/qdio: fine-tune the queue sync
Push the sync check from qdio_inspect_queue() down into the two
get_*_buffer_frontier() code paths, where we actually need the sync to
look at the current queue state. This lets us avoid the check when we
know that there is no work on the queue (ie. when q->nr_buf_used is 0).

While at it introduce the qdio_sync_*_queue() helpers, so that we can
avoid the branch on q->is_input_q when we already know the queue type.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-08-18 10:01:28 +02:00
Julian Wiedmann 10376b5350 s390/qdio: clean up SIGA capability tracking
Don't bother with translating the SIGA-related capability bits into
our own internal format, just cache the full qdioac1 field instead.

Also adjust the helper macros so that they take a qdio_irq argument
and can be used everywhere, instead of taking a qdio_q and then
internally dereferencing the parent pointer.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-08-18 10:01:28 +02:00
Julian Wiedmann eade5f61a5 s390/qdio: use absolute data address in ESTABLISH ccw
Clean up yet another path where HW wants an absolute address, and we've
been implicitly relying on V=R.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-08-18 10:01:27 +02:00
Julian Wiedmann 0ae8f2af26 s390/qdio: remove unneeded siga-sync for Output Queue
get_outbound_buffer_frontier() is only reached via qdio_inspect_queue(),
and there we already call qdio_siga_sync_q() unconditionally.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-27 09:39:18 +02:00
Julian Wiedmann d01fad2c6a s390/qdio: remove remaining tasklet & timer code
Both qdio drivers have moved away from using qdio's internal tasklet
and timer mechanisms for Output Queues. Rip out all the leftovers.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-27 09:39:18 +02:00
Julian Wiedmann d1ea9b58c8 s390/qdio: propagate error when cancelling a ccw fails
If qdio_cancel_ccw() times out (or is interrupted) before the interrupt
for the {halt,clear} action arrives, report this back to the caller as
an error.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-27 09:39:18 +02:00
Julian Wiedmann d06314e0ce s390/qdio: improve roll-back after error on ESTABLISH ccw
If the ESTABLISH ccw fails (ie. the qdio_irq is set to
QDIO_IRQ_STATE_ERR), we don't need to call qdio_shutdown() for rolling
back our earlier actions. All the needed logic is already available in
qdio_establish()'s error chain, and using it means we don't have to
temporarily drop the setup_mutex either.

This makes qdio_shutdown() a purely external function, that should only
be called by the driver if an earlier qdio_establish() succeeded.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-27 09:39:18 +02:00
Julian Wiedmann 1c1dc8bda3 s390/qdio: cancel the ESTABLISH ccw after timeout
When the ESTABLISH ccw does not complete within the specified timeout,
try our best to cancel the ccw program that is still active on the
device. Otherwise the IO subsystem might be accessing it even after
the driver eg. called qdio_free().

Fixes: 779e6e1c72 ("[S390] qdio: new qdio driver.")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Cc: <stable@vger.kernel.org> # 2.6.27
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-27 09:39:18 +02:00
Julian Wiedmann 2c197870e4 s390/qdio: fix roll-back after timeout on ESTABLISH ccw
When qdio_establish() times out while waiting for the ESTABLISH ccw to
complete, it calls qdio_shutdown() to roll back all of its previous
actions. But at this point the qdio_irq's state is still
QDIO_IRQ_STATE_INACTIVE, so qdio_shutdown() will exit immediately
without doing any actual work.

Which means that eg. the qdio_irq's thinint-indicator stays registered,
and cdev->handler isn't restored to its old value. And since
commit 954d6235be ("s390/qdio: make thinint registration symmetric")
the qdio_irq also stays on the tiq_list, so on the next qdio_establish()
we might get a helpful BUG from the list-debugging code:

...
[ 4633.512591] list_add double add: new=00000000005a4110, prev=00000001b357db78, next=00000000005a4110.
[ 4633.512621] ------------[ cut here ]------------
[ 4633.512623] kernel BUG at lib/list_debug.c:29!
...
[ 4633.512796]  [<00000001b2c6ee9a>] __list_add_valid+0x82/0xa0
[ 4633.512798] ([<00000001b2c6ee96>] __list_add_valid+0x7e/0xa0)
[ 4633.512800]  [<00000001b2fcecce>] qdio_establish_thinint+0x116/0x190
[ 4633.512805]  [<00000001b2fcbe58>] qdio_establish+0x128/0x498
...

Fix this by extracting a goto-chain from the existing error exits in
qdio_establish(), and check the return value of the wait_event_...()
to detect the timeout condition.

Fixes: 779e6e1c72 ("[S390] qdio: new qdio driver.")
Root-caused-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Cc: <stable@vger.kernel.org> # 2.6.27
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-07-27 09:39:17 +02:00
Heiko Carstens d3e2ff5436 s390/qdio: get rid of register asm
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-06-28 11:18:29 +02:00
Julian Wiedmann 396c100472 s390/qdio: let driver manage the QAOB
We are spending way too much effort on qdio-internal bookkeeping for
QAOB management & caching, and it's still not robust. Once qdio's
TX path has detached the QAOB from a PENDING buffer, we lost all
track of it until it shows up in a CQ notification again. So if the
device is torn down before that notification arrives, we leak the QAOB.

Just have the driver take care of it, and simply pass down a QAOB if
they want a TX with async-completion capability. For a buffer in PENDING
state that requires the QAOB for final completion, qeth can now also try
to recycle the buffer's QAOB rather than unconditionally freeing it.

This also eliminates the qdio_outbuf_state array, which was only needed
to transfer the aob->user1 tag from the driver to the qdio layer.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2021-03-22 11:36:05 +01:00
Julian Wiedmann 2223318c28 s390/qdio: remove 'merge_pending' mechanism
For non-QEBSM devices, get_buf_states() merges PENDING and EMPTY buffers
into a single group of finished buffers. To allow the upper-layer driver
to differentiate between the two states, qdio_check_pending() looks at
each buffer's state again and sets the sbal_state flag to
QDIO_OUTBUF_STATE_FLAG_PENDING accordingly.

So effectively we're spending overhead on _every_ Output Queue
inspection, just to avoid some additional TX completion calls in case
a group of buffers has completed with mixed EMPTY / PENDING state.
Given that PENDING buffers should rarely occur, this is a bad trade-off.
In particular so as the additional checks in get_buf_states() affect
_all_ device types (even those that don't use the PENDING state).

Rip it all out, and just report the PENDING completions separately as
we already do for QEBSM devices.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13 17:17:55 +01:00
Julian Wiedmann 7940eaf2e9 s390/qdio: improve handling of PENDING buffers for QEBSM devices
For QEBSM devices the 'merge_pending' mechanism in get_buf_states()
doesn't apply, and we can actually get SLSB_P_OUTPUT_PENDING returned.

So for this case propagating the PENDING state to the driver via the
queue's sbal_state doesn't make sense and creates unnecessary overhead.
Instead introduce a new QDIO_ERROR_* flag that gets passed to the
driver, and triggers the same processing as if the buffers were flagged
as QDIO_OUTBUF_STATE_FLAG_PENDING.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13 17:17:55 +01:00
Julian Wiedmann 540936df44 s390/qdio: rework q->qdio_error indication
When inspecting a queue, any error is currently returned back through
the queue's qdio_error field. Turn this into a proper variable that gets
passed through the call chain, so that the lifetime is clear and the
error state can be accessed along the way.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13 17:17:55 +01:00
Julian Wiedmann 3bf526e036 s390/qdio: inline qdio_kick_handler()
We don't kick the handler for Input Queues anymore. Move the remaining
code into its only caller.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-13 17:17:55 +01:00
Julian Wiedmann bd83917155 s390/qdio: track time of last data IRQ for each device
We currently track the time of the most recent QDIO Adapter Interrupt.
This is a system-wide timestamp (as such interrupts are not bound to
one specific qdio device).

If interrupt processing stalls on one device but is functional for a
different device, the timestamp continues to be updated and is of no
help for problem diagnosis.
So for debugging purposes also track the time of the last Data IRQ on
a per-device level. Collect this data in the legacy non-AI path as well.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09 15:57:04 +01:00
Julian Wiedmann 954d6235be s390/qdio: make thinint registration symmetric
tiqdio_add_device() adds the device to the tiq_list of eligible targets
for a data IRQ, which gets walked on each QDIO Adapter Interrupt to
inspect their DSCIs.

But currently the tiqdio_add_device() / tiqdio_remove_device() calls
are not symmetric - the device is removed within qdio_shutdown(),
but only added by qdio_activate().
So depending on the call sequence and encountered errors, we might
be trying to remove a list entry in qdio_shutdown() that was never even
added to the list. This required additional INIT_LIST_HEAD() calls to
ensure that the list entry was always in a consistent state.

All drivers now fence the IRQ delivery via qdio_start_irq() /
qdio_stop_irq(), so we can nicely integrate this tiq_list management
with the other steps needed for QDIO Adapter IRQ (de-)registration
(qdio_establish_thinint() / qdio_shutdown_thinint()).
As the naming suggests these get called during qdio_establish() and
qdio_shutdown(), with proper symmetry and roll-back after errors.

With this we longer need to worry about misplaced list removals, and
thus can clean up the list API abuse (INIT_LIST_HEAD() should not be
called on list entries).

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09 15:57:04 +01:00
Julian Wiedmann 6bb7a51b60 s390/qdio: adopt new tasklet API
Convert the Output Queue tasklet code to take a tasklet_struct as
parameter. Then initialize the tasklet with tasklet_setup() to indicate
that we follow the new model.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09 15:57:04 +01:00
Julian Wiedmann ed645696e0 s390/qdio: remove qdio_inbound_q_moved() wrapper
It's used in just one place, inline it.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09 15:57:04 +01:00
Julian Wiedmann 1ecbcfd57e s390/qdio: remove Input tasklet code
Both qeth and zfcp have fully moved to the polling-driven flow for
Input Queues with commit 0a6e634535 ("s390/qdio: extend polling
support to multiple queues") and commit 0b524abc2d ("scsi: zfcp: Lift
Input Queue tasklet from qdio").

So remove the tasklet code for Input Queues, streamline the IRQ handlers
and push the tasklet struct into struct qdio_output_q.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-02-09 15:57:04 +01:00
Julian Wiedmann 180a4c42e5 s390/qdio: always use dev_name() for device name in QIB
Passing a custom name from the device driver is nice - but in practice
it's only zfcp who has been using this. So we might as well hard-code
a naming scheme in the qdio layer, so that qeth also benefits from it.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-14 10:30:07 +02:00
Julian Wiedmann 309f98dbc6 s390/qdio: make qdio_handle_aobs() more robust
When processing a PENDING buffer with no attached aob, the current code
would get stuck on this buffer (as the 'continue' causes us to not
advance the buffer index) and process it repeatedly until the loop
terminates eventually.

Luckily this should never happen - the HW must not use the PENDING state
when no aob was provided. But we can still make this code path less
fragile and protect against buggy devices.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-14 10:30:07 +02:00
Julian Wiedmann a709423f7a s390/qdio: remove internal polling in non-thinint path
For non-thinint devices in LPAR, qdio polls an idle Input Queue for a
little while to catch more work. But platform support for thinints has
been around practically _forever_ by now, so this micro-optimization is
seeing 0 actual use. Remove it to reduce the overall complexity of the
hot path.

In the meantime we also grew support for driver-level polling
(eg. NAPI in qeth), so it's quite questionable how useful this would
actually be on current kernels.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-07-20 10:55:26 +02:00
Julian Wiedmann 2bbf282a5e s390/qdio: allow to scan all 128 Input SBALs
The comment is inaccurate, qdio_inbound_q_moved() and/or its callers no
longer get confused by a count of 128 completed SBALs.

Scanning all 128 SBALs at once can improve IRQ reduction (as we now
place the ACK at the right spot), and reduce the amount of processing
needed to handle all completed SBALs.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-07-20 10:55:22 +02:00
Julian Wiedmann 529683d470 s390/qdio: fix statistics for 128 SBALs
Old code would only scan up to 127 SBALs at once. So the last statistics
bucket was set aside to count "discovered 127 SBALs with new work"
events.

But nowadays we allow to scan all 128 SBALs for Output Queues, and a
subsequent patch will introduce the same for Input Queues.
So fix up the accounting to use the last bucket only when all 128 SBALs
have been discovered with new work.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-07-20 10:55:18 +02:00
Julian Wiedmann c920c54528 s390/qdio: warn about unexpected SLSB states
The way we produce SBALs to the device (first update q->nr_buf_used,
then update the SLSB) should ensure that we never see some of the
SLSB states when scanning the queue for progress.
So make some noise if we do, this implies a bug in our SBAL tracking.

Also tweak the WARN msg to provide more information.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-17 23:05:05 +02:00
Julian Wiedmann 3d6c6f20d9 s390/qdio: clean up usage of qdio_data
This removes the last remaining accesses to ->qdio_data from internal
code. Just pass the qdio_irq struct where needed instead.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-17 23:05:05 +02:00
Julian Wiedmann a87ee11607 s390/qdio: reduce SLSB writes during Input Queue processing
Streamline the processing of QDIO Input Queues, and remove some
intermittent SLSB updates (no deleting of old ACKs, no redundant
transitions through NOT_INIT).

Rather than counting ACKs, we now keep track of the whole batch of
SBALs that were completed during the current polling cycle.
Most completed SBALs stay in their initial state (ie. PRIMED or ERROR),
except that the most recent SBAL in each sub-run is ACKed for
IRQ reduction.

The only logic changes happen in inbound_handle_work(), the other
delta is just a renaming of the variables that track the SBAL batch.

Note that in particular we don't need to flip the _oldest_ SBAL to
an idle state (eg. NOT_INIT or ACKed) as a guard against catching our
own tail. Since get_inbound_buffer_frontier() will never scan more than
the remaining nr_buf_used SBALs, this scenario just doesn't occur.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16 13:44:04 +02:00
Julian Wiedmann c119a8a3c3 s390/qdio: fine-tune SLSB update
xchg() for a single-byte location assembles to a 4-byte Compare&Swap,
wrapped into a non-trivial amount of retry code that deals with
concurrent modifications to the unaffected bytes.

Change it to a simple byte-store, but preserve the memory ordering
semantics that the CS provided.
This simplifies the generated code for a hot path, and in theory also
allows us to amortize the memory barriers over multiple SLSB updates.

CC: Andreas Krebbel <krebbel@linux.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-06-16 13:44:03 +02:00
Alexandra Winter a0138f5926 s390/cio, s390/qeth: cleanup PNSO CHSC
CHSC3D (PNSO - perform network subchannel operation) is used for
OC0 (Store-network-bridging-information) as well as for
OC3 (Store-network-address-information). So common fields are renamed
from *brinfo* to *pnso*.
Also *_bridge_host_* is changed into *_addr_change_*, e.g.
qeth_bridge_host_event to qeth_addr_change_event, for the
same reasons.
The keywords in the card traces are changed accordingly.

Remove unused L3 types, as PNSO will only return Layer2 entries.

Make PNSO CHSC implementation more consistent with existing API usage:
Add new function ccw_device_pnso() to drivers/s390/cio/device_ops.c and
the function declaration to arch/s390/include/asm/ccwdev.h, which takes
a struct ccw_device * as parameter instead of schid and calls
chsc_pnso().

PNSO CHSC has no strict relationship to qdio. So move the calling
function from qdio to qeth_l2 and move the necessary structures to a
new file arch/s390/include/asm/chsc.h.

Do response code evaluation only in chsc_error_from_response() and
use return code in all other places. qeth_anset_makerc() was meant to
evaluate the PNSO response code, but never did, because pnso_rc was
already non-zero.

Indentation was corrected in some places.

Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Reviewed-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-28 12:21:55 +02:00
Julian Wiedmann cafebf8653 s390/qdio: remove q->first_to_kick
q->first_to_kick is obsolete, and can be replaced by q->first_to_check.

Both cursors start off at 0. Out of the three code paths that update
first_to_check, the qdio_inspect_queue() path is irrelevant as it
doesn't even touch first_to_kick anymore.
This leaves us with the two tasklet-driven code paths. Here any update
to first_to_check is followed by a call to qdio_kick_handler(), which
advances first_to_kick by the same amount.

So the two cursors will differ only for a tiny moment. Drivers have no
way of deterministically observing this difference, and thus it doesn't
matter which of the cursors we use for reporting an error to q->handler.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-28 12:21:55 +02:00
Julian Wiedmann 0623b7dda2 s390/qdio: fix up qdio_start_irq() kerneldoc
Document the actual semantics, correcting an old copy & paste mistake.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-28 12:21:55 +02:00
Julian Wiedmann c70d82e966 s390/qdio: add IRQ reduction for error SBALs
SBALs in PRIMED or ERROR state represent new work on the Input Queue.
But while inbound_primed() does all sorts of ACK management for new
PRIMED work, the same handling is currently missing for ERROR work.
In particular the path for ERROR work doesn't clear up _old_ ACKs.

Treat ERROR work the same as PRIMED work, but consider that the QEBSM
auto-ACK feature doesn't apply here. So we need to set the ACK manually,
as if it was a non-QEBSM device.

Note that this doesn't aspire to actually improve performance, the main
goal is to just unify the code paths and have consistent behaviour.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-20 10:22:50 +02:00
Julian Wiedmann 1db85d0e73 s390/qdio: refactor ACK processing for primed SBALs
inbound_primed() currently has two code paths - one for QEBSM that knows
how to deal with multiple ACKs, and a non-QEBSM path that strictly
assumes a single ACK on the queue.

In preparation for a subsequent patch, slightly adjust the non-QEBSM
path so that it can manage a queue with multiple ACKs.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-20 10:22:50 +02:00
Julian Wiedmann 9de6c08700 s390/qdio: simplify overlap calculation on Input refill
Refilling the Input Queue requires additional checks, as the refilled
SBALs can overlap with the ACKs that qdio maintains on the queue.

This code path is way too complex, and does a whole bunch of wrap-around
checks that the modulo arithmetic in sub_buf() takes care of by itself.
So shrink down all that code into a few lines of equivalent
functionality.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-05-20 10:22:50 +02:00
Julian Wiedmann 19d4c761c1 s390/qdio: remove always-true condition
buf_in_between() gets passed q->u.in.ack_start as 'bufnr' parameter.

The ack_start always ranges between 0 and QDIO_MAX_BUFFERS_PER_Q - 1,
so the subsequent check will always return true. Remove it.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:48 +02:00
Julian Wiedmann 9b7012dfc3 s390/qdio: de-duplicate tiqdio_inbound_processing()
Except for some initial thinint-only steps, the processing is identical
to the non-thinint case. So re-use the existing helper.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:48 +02:00
Julian Wiedmann d188cac397 s390/qdio: keep track of allocated queue count
Knowing how many queues we initially allocated allows us to
1) sanity-check a subsequent qdio_establish() request, and
2) walk the queue arrays without further checks. Apply this while
   cleanly splitting qdio_free_queues() into two separate helpers.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:48 +02:00
Julian Wiedmann 2a7cf35c40 s390/qdio: roll-back after queue allocation error
When qdio_allocate_qs() fails, have it deal with its previous
allocations.
This way qdio_allocate() doesn't need to clean up afterwards.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:47 +02:00
Julian Wiedmann edbf3b2a87 s390/qdio: do more fine-grained allocation roll-back
Instead of having a catch-all qdio_release_memory() helper, free the
individual allocations from the respective error path.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:47 +02:00
Julian Wiedmann 3050f022df s390/qdio: consolidate thinint init/exit
Wrap the init/exit steps for thinint into a single helper that follows
the established naming scheme.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Steffen Maier <maier@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:47 +02:00
Julian Wiedmann 68a381746f s390/qdio: tear down thinint indicator after early error
qdio_establish() calls qdio_establish_thinint(), but later has an error
exit path that doesn't roll this call back. Fix it.

Fixes: 779e6e1c72 ("[S390] qdio: new qdio driver.")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-28 13:49:47 +02:00