Subchannel refcounting was incorrect in some places, especially
a refcount was missing when ccw_device_call_sch_unregister()
was called and the refcount was not correctly switched after
moving devices.

Fix this by establishing the following rules:
- The ccw_device obtains a reference on its parent subchannel
  when dev.parent is set and gives it up in its release
  function. This is needed because we need a parent reference
  for correct refcounting even before the ccw device is (if at
  all) registered.
- When calling device_move(), obtain a reference on the new
  subchannel before moving the ccw device and give up the
  reference on the old parent after moving. This brings the
  refcount in line with the first rule.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The current code attempts to get an extra reference count
for online devices by doing a get_device() in ccw_device_online()
and a put_device() in ccw_device_done(). However, this
- incorrectly obtains an extra reference for disconnected
  devices becoming available again (since they are already
  online)
- needs special checks for css_init_done in order to handle
  the console device
- is not obvious and
- may incorretly drop a reference count in ccw_device_done() if
  that function is called after path verification for a device
  that just became not operational.

So let's just get the reference in ccw_device_set_online() and
drop it in ccw_device_set_offline(). (Unfortunately, we still
need the special case in io_subchannel_probe().)
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Ensure atomicity of ungroup operation to prevent concurrent ungroup
and online processing which may lead to use-after-release situations.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Due to former patches a comment and device id initialization were
split from the addressed function call in io_subchannel_probe.

Move it back to where it belongs.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Move cio_tpi() to the rest of the CONFIG_CCW_CONSOLE functions to
get rid of this one:

drivers/s390/cio/cio.c:115: warning: 'cio_tpi' defined but not used
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

__dasd_cleanup_cqr should be called with request_queue_lock held and
__dasd_block_process_erp with queue_lock
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

SIM sense data are always 32 bit sense data so sense byte 27 bit 0
has not to be set.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

For a large number of I/O requests the values were shifted binary.
The shift was not transparent for the user because the shift value
was not displayed. To make this interface more human readable the
values are shifted decimal and the scale factor is displayed.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Register zfcp with the new /proc/service_level interface to report the
FCP microcode level. When the adapter goes offline or a channel path
disappears, zfcp unregisters, since the microcode version might change
and zfcp does not know about it.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add a new proc interface /proc/service_levels that allows any code
to report a relevant service level, e.g. the microcode level of
devices, the service level of the hypervisor, etc.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Hipersocket connections can encounter temporary busy conditions.
In case of the busy bit set we retry the SIGA operation immediatelly.
If the busy condition still persists after 100 ms we fail and report
the error to the upper layer. The second stage retry logic is removed.
In case of ongoing busy conditions the upper layer needs to reset the
connection.

The reporting of a SIGA error is now done synchronously to allow the
network driver to requeue the buffers. Also no error trace is created
for the temporary SIGA errors so the error message view is not flooded.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

- Use automatic acknowledgement of incoming buffers in QEBSM mode
- Move ACK for non-QEBSM mode always to the newest buffer to prevent
  a race with qdio_stop_polling
- Remove the polling spinlock, the upper layer drivers return new buffers
  in the same code path and could not run in parallel
- Don't flood the error log in case of no-target-buffer-empty
- In handle_inbound we check if we would overwrite an ACK'ed buffer, if so
  advance the pointer to the oldest ACK'ed buffer so we don't overwrite an
  empty buffer in qdio_stop_polling
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

- make qdio_trace a per device view
- remove s390dbf exceptions
- remove CONFIG_QDIO_DEBUG, not needed anymore if we check for the level
  before calling sprintf
- use snprintf for dbf entries
- add start markers to see if the dbf view wrapped
- add a global error view for all queues
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The QEBSM instructions are only available for CONFIG_64BIT, they are not
used under 31 bit. Make compiler happy about the false positive:

drivers/s390/cio/qdio_main.c: In function ?qdio_inbound_q_done?:
drivers/s390/cio/qdio_main.c:532: warning: ?state? may be used uninitialized in this function
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add counters for the eqbs and sqbs instructions that indicate how often
we issued the instructions and how often the instructions returned with
less buffers than specified.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

qeth needs to get the port count information before
qdio has allocated a page for the chsc operation.
Extend qdio_get_ssqd_desc() to store the data in the
specified structure.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Changed some symbol names for a better and clearer code.
Signed-off-by: NChristian Maaser <cmaaser@de.ibm.com>
Signed-off-by: NFelix Beck <beckf@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When the machine supports AP adapter interrupts polling will be
switched off at module initialization and the driver will work in
interrupt mode.
Signed-off-by: NFelix Beck <felix.beck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The vmcp driver uses the session->mutex for concurrent access of the data
structures. Therefore, the BKL in vmcp_open does not protect against any
other function in the driver.
The BLK in vmcp_open would protect concurrent access to the module init
but all necessary steps ave finished before misc_register is called.
We can safely remove the lock_kernel from vcmp.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The zfcp_scsi_queuecommand was not acting according to the standard
when the respective unit was not available. In this case an -EBUSY was
returned, which is not valid in itself, and in addition scsi_done
was called. This combination is not allowed and was leading to a
double finish of the request and therefor double decrement of the
host_busy counter.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Waiting for the ERP to be finished in a task running in the global
kernel work-queue is a bad idea, especially if the ERP needs to run
another job in this work-queue before it can finish. -> deadlock.

This patch removes the necessity to wait for a finished ERP from the
scan task and moves the job scheduling to the end of the ERP.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The check of having a valid pointer was performed before the
processing was secured by the lock. Between those two steps the
pointer can turn invalid.  During further processing another value is
used (referenced by the pointer described above) as a function pointer
which is never verified to be valid either, resulting under some
circumstances in an invalid function call.  This patch is fixing both
issues.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Prevent a SCSI target scan for a rport which have turned invalid
in the meantime.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Aborting a SCSI cmnd might requrie to send a abort_fsf_cmnd. If the
creation of this fsf_req fails an ERR_PTR is returned where a NULL
value would be expected as an error indicator. This ERR_PTR is
dereferenced as valid fsf_req in succeeding processing leading to
an error.
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Running two wka_port_get calls in parallel could issue two open_port
requests, overwriting the port handle. Don't issue an open_port
for the state PORT_OPENING, and only read the data from GOOD
responses.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Acked-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

For an incoming RSCN it was checked by the ZFCP_STATUS_PORT_DID_DID
define to re-open a remote port or to test the connection. Since this
define was re-used it was also necessary to replace that define with
ZFCP_STATUS_PORT_PHYS_OPEN.
Signed-off-by: NMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The logging of sense data for fatal errors was accidentally removed
during Hyper PAV implementation.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In ccw_device_move_to_orphanage(), a replacing ccw_device
is searched via get_{disc,orphaned}_ccwdev_by_dev_id()
which obtain a reference on the returned ccw_device.
This reference must be given up again after the device
has been moved to its new parent.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The current virtio model on s390 has the descriptor page above the main
memory. The guest virtio detection will oops if the mem= parameter is
used to reduce/change the memory size.
We have to use real_memory_size instead of max_pfn to detect the virtio
descriptor pages.
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix multiple problems found in the hexdump data:
 - length calculation was wrong, traces were incomplete
 - FC payloads were dumped in different record than the output
   function tried to read
 - minor fixes in output
 - allow complete RSCN traces (up to 1024 bytes according to spec)
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

If an open port fsf request times out (in erp) the
corresponding erp_action member of the fsf
request need to set to NULL. If the port structure
will be removed later-on there will be still a
reference in the fsf request to the non existing
erp_action otherwise.
Signed-off-by: NMartin Petermann <martin.petermann@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Attaching a unit immediately after setting the adapter online should
be possible. The problem right now is that the port_scan runs from a
workqueue and has not finished when the set_online call returns and
the sysfs structures for the ports are not available yet. Fix that by
waiting for the port scan to complete.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Fix leftover from last typecast patch:

drivers/s390/scsi/zfcp_aux.c: In function ‘zfcp_port_enqueue’:
drivers/s390/scsi/zfcp_aux.c:629: warning: format ‘%016llx’ expects
type ‘long long unsigned int’, but argument 3 has type ‘u64’
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Fix the handling of the request list in the error path:
 - Use irqsave for the lock as in the good path.
 - Before removing the request, check if it is still in the list, a
   call to dismiss_all might have changed the list in between.
 - zfcp_qdio_send does not change the queue counters on failure,
   trying revert something is wrong, so remove this.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

When allocating fsf requests without qtcb, store the pointer to the
mempool in the fsf requests for later call to mempool_free. This
codepath is only used by the status_read requests.
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NSwen Schillig <swen@vnet.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

The per adapter req_list_lock must be held with interrupts disabled, otherwise
we might end up with nice deadlocks as lockdep tells us (see below).

zfcp 0.0.1804: QDIO problem occurred.

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
2.6.27-rc8-00035-g4a770358-dirty #86
---------------------------------------------------------
swapper/0 just changed the state of lock:
 (&adapter->erp_lock){++..}, at: [<00000000002c82ae>] zfcp_erp_adapter_reopen+0x4e/0x8c
but this lock took another, hard-irq-unsafe lock in the past:
 (&adapter->req_list_lock){-+..}

and interrupts could create inverse lock ordering between them.

[tons of backtraces, but only the interesting part follows]

the second lock's dependencies:
-> (&adapter->req_list_lock){-+..} ops: 2280627634176 {
   initial-use  at:
                        [<0000000000071f10>] __lock_acquire+0x504/0x18bc
                        [<000000000007335c>] lock_acquire+0x94/0xbc
                        [<00000000003d7224>] _spin_lock_irqsave+0x6c/0xb0
                        [<00000000002cf684>] zfcp_fsf_req_dismiss_all+0x50/0x140
                        [<00000000002c87ee>] zfcp_erp_adapter_strategy_generic+0x66/0x3d0
                        [<00000000002c9498>] zfcp_erp_thread+0x88c/0x1318
                        [<000000000001b0d2>] kernel_thread_starter+0x6/0xc
                        [<000000000001b0cc>] kernel_thread_starter+0x0/0xc
   in-softirq-W at:
                        [<0000000000072172>] __lock_acquire+0x766/0x18bc
                        [<000000000007335c>] lock_acquire+0x94/0xbc
                        [<00000000003d7224>] _spin_lock_irqsave+0x6c/0xb0
                        [<00000000002ca73e>] zfcp_qdio_int_resp+0xbe/0x2ac
                        [<000000000027a1d6>] qdio_kick_inbound_handler+0x82/0xa0
                        [<000000000027daba>] tiqdio_inbound_processing+0x62/0xf8
                        [<0000000000047ba4>] tasklet_action+0x100/0x1f4
                        [<0000000000048b5a>] __do_softirq+0xae/0x154
                        [<0000000000021e4a>] do_softirq+0xea/0xf0
                        [<00000000000485de>] irq_exit+0xde/0xe8
                        [<0000000000268c64>] do_IRQ+0x160/0x1fc
                        [<00000000000261a2>] io_return+0x0/0x8
                        [<000000000001b8f8>] cpu_idle+0x17c/0x224
   hardirq-on-W at:
                        [<0000000000072190>] __lock_acquire+0x784/0x18bc
                        [<000000000007335c>] lock_acquire+0x94/0xbc
                        [<00000000003d702c>] _spin_lock+0x5c/0x9c
                        [<00000000002caff6>] zfcp_fsf_req_send+0x3e/0x158
                        [<00000000002ce7fe>] zfcp_fsf_exchange_config_data+0x106/0x124
                        [<00000000002c8948>] zfcp_erp_adapter_strategy_generic+0x1c0/0x3d0
                        [<00000000002c98ea>] zfcp_erp_thread+0xcde/0x1318
                        [<000000000001b0d2>] kernel_thread_starter+0x6/0xc
                        [<000000000001b0cc>] kernel_thread_starter+0x0/0xc
 }
 ... key      at: [<0000000000e356c8>] __key.26629+0x0/0x8
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NChristof Schmitt <christof.schmit@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>