s390/ap: introduce mutex to lock the AP bus scan

Rework the invocations around ap_scan_bus():
- Protect ap_scan_bus() with a mutex to make sure only one
scan at a time is running.
- The workqueue invocation which is triggered by either the
module init or via AP bus scan timer expiration uses this
mutex and if there is already a scan running, the work
is simple aborted (as the job is done by another task).
- The ap_bus_force_rescan() which is invoked by higher level
layers mostly on failures which indicate a bus scan may
help is reworked to call ap_scan_bus() direct instead of
enqueuing work into a system workqueue and waiting for that
to finish. Of course the mutex is respected and in case of
another task already running a bus scan the shortcut of
waiting for this scan to finish and reusing the scan result
is taken.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: rework ap_scan_bus() to return true on config change

The AP scan bus function now returns true if there have
been any config changes detected. This will become
important in a follow up patch which will exploit this
hint for further actions. This also required to have
the AP scan bus timer callback reworked as the function
signature has changed to bool ap_scan_bus(void).

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: clarify AP scan bus related functions and variables

This patch tries to clarify the functions and variables
around the AP scan bus job. All these variables and
functions start with ap_scan_bus and are declared in
one place now.

No functional changes in this patch - only renaming and
move of code or declarations.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: rearm APQNs bindings complete completion

The APQN bindings complete completion was used to reflect
that 1st the AP bus initial scan is done and 2nd all the
detected APQNs have been bound to a device driver.
This was a single-shot action. However, as the AP bus
supports hot-plug it may be that new APQNs appear reflected
as new AP queue and card devices which need to be bound
to appropriate device drivers. So the condition that
all existing AP queue devices are bound to device drivers
may go away for a certain time.

This patch now checks during AP bus scan for maybe new AP
devices appearing and does a re-init of the internal completion
variable. So the AP bus function ap_wait_apqn_bindings_complete()
now may block on this condition variable even later after
initial scan is through when new APQNs appear which need to
get bound.

This patch also moves the check for binding complete invocation
from the probe function to the end of the AP bus scan function.
This change also covers some weird scenarios where during a
card hotplug the binding of the card device was sufficient for
binding complete but the queue devices where still in the
process of being discovered.

As of now this change has no impact on existing code. The
behavior change in the now later bindings complete should not
impact any code (and has been tested so far). The only
exploiter is the zcrypt function zcrypt_wait_api_operational()
which only initial calls ap_wait_apqn_bindings_complete().

However, this new behavior of the AP bus wait for APQNs bindings
complete function will be used in a later patch exploiting
this for the zcrypt API layer.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: explicitly include ultravisor header

The ap_bus is using inline functions of the ultravisor (uv) in-kernel
API. The related header file is implicitly included via several other
headers. Replace this by an explicit include of the ultravisor header
in the ap_bus file.

Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/zcrypt: introduce dynamic debugging for AP and zcrypt code

This patch replaces all the s390 debug feature calls with
debug level by dynamic debug calls pr_debug. These calls
are much more flexible and each single invocation can get
enabled/disabled at runtime wheres the s390 debug feature
debug calls have only one knob - enable or disable all in
one bunch. The benefit is especially significant with
high frequency called functions like the AP bus scan. In
most debugging scenarios you don't want and need them, but
sometimes it is crucial to know exactly when and how long
the AP bus scan took.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/zcrypt: harmonize debug feature calls and defines

This patch harmonizes the calls and defines around the
s390 debug feature as it is used in the AP bus and
zcrypt device driver code.

More or less cleanup and renaming, no functional changes.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: make ap_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the ap_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240203-bus_cleanup-s390-v1-5-ac891afc7282@marliere.net
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: handle outband SE bind state change

This patch addresses some weird scenarios where an outband
manipulation of the SE bind state of a queue assigned and
maybe in use by an SE guest with AP pass-through support
took place. So for example when the guest has bound and
associated a queue and then this domain has been zeroed on
the service element.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/ap: store TAPQ hwinfo in struct ap_card

As of now the AP card struct held only part of the
queue's hwinfo (that is the GR2 register content returned
with an TAPQ invocation). This patch reworks struct ap_card
to hold the whole hwinfo now.

As there is a nice bit field union on top of this
ap_tapq_hwinfo struct, all the ugly bit checkings can
now get replaced by simple evaluations of the required
bit field.

Suggested-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/ap: fix vanishing crypto cards in SE environment

A secure execution (SE, also known as confidential computing)
guest may see asynchronous errors on a crypto firmware queue.
The current implementation to gather information about cards
and queues in ap_queue_info() simple returns if an asynchronous
error is hanging on the firmware queue. If such a situation
happened and it was the only queue visible for a crypto card
within an SE guest, then the card vanished from sysfs as
the AP bus scan function refuses to hold a card without any
type information. As lszcrypt evaluates the sysfs such
a card vanished from the lszcrypt card listing and the
user is baffled and has no way to reset and thus clear the
pending asynchronous error.

This patch improves the named function to also evaluate GR2
of the TAPQ in case of asynchronous error pending. If there
is a not-null value stored in, the info is processed now.
In the end, a queue with pending asynchronous error does not
lead to a vanishing card any more.

Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: fix AP bus crash on early config change callback invocation

Fix kernel crash in AP bus code caused by very early invocation of the
config change callback function via SCLP.

After a fresh IML of the machine the crypto cards are still offline and
will get switched online only with activation of any LPAR which has the
card in it's configuration. A crypto card coming online is reported
to the LPAR via SCLP and the AP bus offers a callback function to get
this kind of information. However, it may happen that the callback is
invoked before the AP bus init function is complete. As the callback
triggers a synchronous AP bus scan, the scan may already run but some
internal states are not initialized by the AP bus init function resulting
in a crash like this:

[ 11.635859] Unable to handle kernel pointer dereference in virtual kernel address space
[ 11.635861] Failing address: 0000000000000000 TEID: 0000000000000887
[ 11.635862] Fault in home space mode while using kernel ASCE.
[ 11.635864] AS:00000000894c4007 R3:00000001fece8007 S:00000001fece7800 P:000000000000013d
[ 11.635879] Oops: 0004 ilc:1 [#1] SMP
[ 11.635882] Modules linked in:
[ 11.635884] CPU: 5 PID: 42 Comm: kworker/5:0 Not tainted 6.6.0-rc3-00003-g4dbf7cdc6b42 #12
[ 11.635886] Hardware name: IBM 3931 A01 751 (LPAR)
[ 11.635887] Workqueue: events_long ap_scan_bus
[ 11.635891] Krnl PSW : 0704c00180000000 0000000000000000 (0x0)
[ 11.635895] R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3
[ 11.635897] Krnl GPRS: 0000000001000a00 0000000000000000 0000000000000006 0000000089591940
[ 11.635899] 0000000080000000 0000000000000a00 0000000000000000 0000000000000000
[ 11.635901] 0000000081870c00 0000000089591000 000000008834e4e2 0000000002625a00
[ 11.635903] 0000000081734200 0000038000913c18 000000008834c6d6 0000038000913ac8
[ 11.635906] Krnl Code:>0000000000000000: 0000 illegal
[ 11.635906] 0000000000000002: 0000 illegal
[ 11.635906] 0000000000000004: 0000 illegal
[ 11.635906] 0000000000000006: 0000 illegal
[ 11.635906] 0000000000000008: 0000 illegal
[ 11.635906] 000000000000000a: 0000 illegal
[ 11.635906] 000000000000000c: 0000 illegal
[ 11.635906] 000000000000000e: 0000 illegal
[ 11.635915] Call Trace:
[ 11.635916] [<0000000000000000>] 0x0
[ 11.635918] [<000000008834e4e2>] ap_queue_init_state+0x82/0xb8
[ 11.635921] [<000000008834ba1c>] ap_scan_domains+0x6fc/0x740
[ 11.635923] [<000000008834c092>] ap_scan_adapter+0x632/0x8b0
[ 11.635925] [<000000008834c3e4>] ap_scan_bus+0xd4/0x288
[ 11.635927] [<00000000879a33ba>] process_one_work+0x19a/0x410
[ 11.635930] Discipline DIAG cannot be used without z/VM
[ 11.635930] [<00000000879a3a2c>] worker_thread+0x3fc/0x560
[ 11.635933] [<00000000879aea60>] kthread+0x120/0x128
[ 11.635936] [<000000008792afa4>] __ret_from_fork+0x3c/0x58
[ 11.635938] [<00000000885ebe62>] ret_from_fork+0xa/0x30
[ 11.635942] Last Breaking-Event-Address:
[ 11.635942] [<000000008834c6d4>] ap_wait+0xcc/0x148

This patch improves the ap_bus_force_rescan() function which is
invoked by the config change callback by checking if a first
initial AP bus scan has been done. If not, the force rescan request
is simple ignored. Anyhow it does not make sense to trigger AP bus
re-scans even before the very first bus scan is complete.

Cc: stable@vger.kernel.org
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: re-init AP queues on config on

On a state toggle from config off to config on and on the
state toggle from checkstop to not checkstop the queue's
internal states was set but the state machine was not
nudged. This did not care as on the first enqueue of a
request the state machine kick ran.

However, within an Secure Execution guest a queue is
only chosen by the scheduler when it has been bound.
But to bind a queue, it needs to run through the initial
states (reset, enable interrupts, ...). So this is like
a chicken-and-egg problem and the result was in fact
that a queue was unusable after a config off/on toggle.

With some slight rework of the handling of these states
now the new function _ap_queue_init_state() is called
which is the core of the ap_queue_init_state() function
but without locking handling. This has the benefit that
it can be called on all the places where a (re-)init
of the AP queue's state machine is needed.

Fixes: 2d72eaf036d2 ("s390/ap: implement SE AP bind, unbind and associate")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt_ep11misc: support API ordinal 6 with empty pin-blob

Secure execution guest environments require an empty pinblob in all
key generation and unwrap requests. Empty pinblobs are only available
in EP11 API ordinal 6 or higher.

Add an empty pinblob to key generation and unwrap requests, if the AP
secure binding facility is available. In all other cases, stay with
the empty pin tag (no pinblob) and the current API ordinals.

The EP11 API ordinal also needs to be considered when the pkey module
tries to figure out the list of eligible cards for key operations
with protected keys in secure execution environment.

These changes are transparent to userspace but required for running
an secure execution guest with handling key generate and key derive
(e.g. secure key to protected key) correct. Especially using EP11
secure keys with the kernel dm-crypt layer requires this patch.

Co-developed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/zcrypt: remove CEX2 and CEX3 device drivers

Remove the legacy device driver code for CEX2 and CEX3 cards.

The last machines which are able to handle CEX2 crypto cards
are z10 EC first available 2008 and z10 BC first available 2009.
The last machines able to handle a CEX3 crypto card are
z196 first available 2010 and z114 first available 2011.

Please note that this does not imply to drop CEX2 and CEX3
support in general. With older kernels on hardware up to the
aforementioned machine models these crypto cards will get
support by IBM.

The removal of the CEX2 and CEX3 device drivers code opens up
some simplifications, for example support for crypto cards
without rng support can be removed also.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390: fix various typos

Fix various typos found with codespell.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/ap: add ap status asynch error support

Review and extend the low level AP code to be able to
deal with asynchronous reported errors on APQNs.

The hypervisor and the SE guest may be confronted with
an asynchronously reported error at return of an AP
instruction. So all places where AP instructions are
called need review and may eventually need extensions.
However, not all places need rework. As together with
the AP status and the enabled asynch bit there is always
a response code set. The asynch error reporting comes
with new response codes which may be simple handled in
the default case of a switch statement.

The idea behind this patch is to report asynch errors
as -EPERM (read this as "Operation not permitted") which
reflects the fact that only a rapq (with F bit enabled)
is a valid AP instruction when an asynch error is flagged.

The AP queue state machine functions return
AP_SM_WAIT_NONE when a asynch error is detected to reflect
the fact, that the state machine can't do anything with
such an error as long as the queue is reset.

Unfortunately the ap bus scan function needed some
update as the ap_queue_info() now needs to return
3 states: 1 if an APQN exists and info is available,
-1 if it is assumed an APQN does not exist and the new
return value 0 without any info values filled. This 0
returncode is handled as "there is an APQN but we currently
don't know any more hw info about this, so please use
your previous info and try again later".

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: introduce low frequency polling possibility

For some events the ap bus needs to poll. For example
when an AP queue is reset until the reset is through.
Also when no interrupt support is available (e.g. zVM)
there is a need to poll until all requests have been
processed and all replies have been delivered.

Polling is done with a high resolution timer by default
run with a rate of 4kHz (LPAR) or 666Hz (zVM guest).

For some events (wait for reset complete, wait for irq
enabled complete) this is a much too high poll rate
which triggers a lot of TAPQ invocations.

This patch introduces the possibility for the state
machine functions to return a new wait enum
AP_SM_WAIT_LOW_TIMEOUT which gives a hint to the
ap_wait() function to eventually set up the timer
with a more relaxed timeout value of 25Hz.

This patch also includes a slight rework of the sysfs
functions parsing the timer related stuff: Use of
kstrtobool and kstrtoul instead of sscanf.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: filter ap card functions, new queue functions attribute

With SE SB (Secure Binding) some currently unused and thus always
zero bits in the TAPQ GR2 result are now used to show the binding
state of a queue. So to check if a card has changed the comparing
base is exactly this GR2 value shown as 'ap_function' in sysfs
(/sys/devices/ap/cardxx/ap_functions). Now there is some queue
specific info in this info and so a new mask TAPQ_CARD_FUNC_CMP_MASK
is used to filter out only the relevant bits for card compare.

For the same reason now the function bits (including exactly this
bind/associate information) need to be exposed to user space now.
So tools like lszcrypt can evaluate binding/association state on a
queue base. So here comes a new sysfs attribute

/sys/devices/ap/cardxx/xx.yyyy/ap_functions

This sysfs attribute is similar to the already existing
ap_functions attribute at ap card level. It shows the
upper 32 bits of GR2 from an invocation of TAPQ for this
AP queue.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: make tapq gr2 response a struct

This patch introduces a new struct ap_tapq_gr2 which covers
the response in GR2 on TAPQ invocation. This makes it much
easier and less error-prone for the calling functions to
access the right field without shifting and masking.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: introduce new AP bus sysfs attribute features

Introduce a new AP bus sysfs attribute /sys/bus/ap/features
which shows the features from the QCI information.
Currently these feature bits are evaluated:

- QCI S bit is shown as 'APSC'
- QCI N bit is shown as 'APXA'
- QCI C bit is shown as 'QACT'
- QCI R bit is shown as 'RC8A'
- QCI B bit is shown as 'APSB'

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: exploit new B bit from QCI config info

This patch introduces an update to the ap_config_info
struct which is filled with the QCI subfunction. There
is a new bit apsb (short 'B') showing if the AP secure
bind facility is available. The patch also includes a
simple function ap_sb_available() wrapping this bit test.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/zcrypt: replace scnprintf with sysfs_emit

Replace scnprintf() with sysfs_emit() and friends
where possible.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

driver core: bus: mark the struct bus_type for sysfs callbacks as constant

struct bus_type should never be modified in a sysfs callback as there is
nothing in the structure to modify, and frankly, the structure is almost
never used in a sysfs callback, so mark it as constant to allow struct
bus_type to be moved to read-only memory.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Ben Widawsky <bwidawsk@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hu Haowen <src.res@email.cn>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Stuart Yoder <stuyoder@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Acked-by: Ilya Dryomov <idryomov@gmail.com> # rbd
Acked-by: Ira Weiny <ira.weiny@intel.com> # cxl
Reviewed-by: Alex Shi <alexs@kernel.org>
Acked-by: Iwona Winiarska <iwona.winiarska@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> # pci
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com> # scsi
Link: https://lore.kernel.org/r/20230313182918.1312597-23-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

driver core: make struct bus_type.uevent() take a const *

The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

s390/ap: fix memory leak in ap_init_qci_info()

If kzalloc() for 'ap_qci_info_old' failed, 'ap_qci_info' shold be
freed before return. Otherwise it is a memory leak.

Link: https://lore.kernel.org/r/20221114110830.542246-1-weiyongjun@huaweicloud.com
Fixes: 283915850a44 ("s390/ap: notify drivers on config changed and scan complete callbacks")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/ap: fix crash on older machines based on QCI info missing

On older z series machines (z12 and older) there is no QCI info
available. The AP code took care of this and the AP bus scan then
switched to simple probing via TAPQ.

With commit
283915850a44 ("s390/ap: notify drivers on config changed and scan complete callbacks")
some code was introduced which silently assumed that the QCI info is
always available. However, with KVM simulating an older machine (z12)
the result was a kernel crash. Funnily the same crash does not happen
on LPAR - maybe because NULL is a valid pointer and reading some data
from address 0 also works fine.

This fix now improves the code to be aware that the QCI instruction
may not be available on older machines and thus the two pointers to
QCI info structs may simple be NULL.

However, on a machine not providing the QCI info the two callbacks to
the zcrypt device drivers on_config_changed() and on_scan_complete()
provide parameters which are pointers to a QCI info struct.
These both callbacks are NOT served if there is no QCI info available.
The only consumer of these callbacks is the vfio device driver. This
driver only supports CEX4 and higher. All physical machines which are
able to provide CEX4 cards have QCI support available. So there is
no sense in for example fill the QCI info struct by hand with looping
over cards and queues and TAPQ each APQN.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: stable@vger.kernel.org
Fixes: 283915850a44 ("s390/ap: notify drivers on config changed and scan complete callbacks")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/vfio-ap: implement in-use callback for vfio_ap driver

Let's implement the callback to indicate when an APQN
is in use by the vfio_ap device driver. The callback is
invoked whenever a change to the apmask or aqmask would
result in one or more queue devices being removed from the driver. The
vfio_ap device driver will indicate a resource is in use
if the APQN of any of the queue devices to be removed are assigned to
any of the matrix mdevs under the driver's control.

There is potential for a deadlock condition between the
matrix_dev->guests_lock used to lock the guest during assignment of
adapters and domains and the ap_perms_mutex locked by the AP bus when
changes are made to the sysfs apmask/aqmask attributes.

The AP Perms lock controls access to the objects that store the adapter
numbers (ap_perms) and domain numbers (aq_perms) for the sysfs
/sys/bus/ap/apmask and /sys/bus/ap/aqmask attributes. These attributes
identify which queues are reserved for the zcrypt default device drivers.
Before allowing a bit to be removed from either mask, the AP bus must check
with the vfio_ap device driver to verify that none of the queues are
assigned to any of its mediated devices.

The apmask/aqmask attributes can be written or read at any time from
userspace, so care must be taken to prevent a deadlock with asynchronous
operations that might be taking place in the vfio_ap device driver. For
example, consider the following:

1. A system administrator assigns an adapter to a mediated device under the
control of the vfio_ap device driver. The driver will need to first take
the matrix_dev->guests_lock to potentially hot plug the adapter into
the KVM guest.
2. At the same time, a system administrator sets a bit in the sysfs
/sys/bus/ap/ap_mask attribute. To complete the operation, the AP bus
must:
a. Take the ap_perms_mutex lock to update the object storing the values
for the /sys/bus/ap/ap_mask attribute.
b. Call the vfio_ap device driver's in-use callback to verify that the
queues now being reserved for the default zcrypt drivers are not
assigned to a mediated device owned by the vfio_ap device driver. To
do the verification, the in-use callback function takes the
matrix_dev->guests_lock, but has to wait because it is already held
by the operation in 1 above.
3. The vfio_ap device driver calls an AP bus function to verify that the
new queues resulting from the assignment of the adapter in step 1 are
not reserved for the default zcrypt device driver. This AP bus function
tries to take the ap_perms_mutex lock but gets stuck waiting for the
waiting for the lock due to step 2a above.

Consequently, we have the following deadlock situation:

matrix_dev->guests_lock locked (1)
ap_perms_mutex lock locked (2a)
Waiting for matrix_dev->gusts_lock (2b) which is currently held (1)
Waiting for ap_perms_mutex lock (3) which is currently held (2a)

To prevent this deadlock scenario, the function called in step 3 will no
longer take the ap_perms_mutex lock and require the caller to take the
lock. The lock will be the first taken by the adapter/domain assignment
functions in the vfio_ap device driver to maintain the proper locking
order.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/airq: pass more TPI info to airq handlers

A subsequent patch will introduce an airq handler that requires additional
TPI information beyond directed vs floating, so pass the entire tpi_info
structure via the handler. Only pci actually uses this information today,
for the other airq handlers this is effectively a no-op.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20220606203325.110625-6-mjrosato@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>

s390/ap: fix error handling in __verify_queue_reservations()

The AP bus's __verify_queue_reservations function increments the ref count
for the device driver passed in as a parameter, but fails to decrement it
before returning control to the caller. This will prevents any subsequent
removal of the module.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reported-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Fixes: 4f8206b88286 ("s390/ap: driver callback to indicate resource in use")
Link: https://lore.kernel.org/r/20220706222619.602094-1-akrowiak@linux.ibm.com
Cc: stable@vger.kernel.org
[agordeev@linux.ibm.com fixed description, added Fixes and Link]
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

s390/zcrypt: code cleanup

This patch tries to fix as much as possible of the
checkpatch.pl --strict findings:
CHECK: Logical continuations should be on the previous line
CHECK: No space is necessary after a cast
CHECK: Alignment should match open parenthesis
CHECK: 'useable' may be misspelled - perhaps 'usable'?
WARNING: Possible repeated word: 'is'
CHECK: spaces preferred around that '*' (ctx:VxV)
CHECK: Comparison to NULL could be written "!msg"
CHECK: Prefer kzalloc(sizeof(*zc)...) over kzalloc(sizeof(struct...)...)
CHECK: Unnecessary parentheses around resp_type->work
CHECK: Avoid CamelCase: <xcRB>

There is no functional change comming with this patch, only
code cleanup, renaming, whitespaces, indenting, ... but no
semantic change in any way. Also the API (zcrypt and pkey
header file) is semantically unchanged.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: uevent on apmask/aqpmask change

This patch introduces user space notifications for changes
on the apmask or aqmask attributes. So it could be possible
to write a udev rule to load/unload the vfio_ap kernel module
based on changes of these masks.

On chance of the apmask or aqmask an AP change event will
be produced with an uevent environment variable showing
the new APMASK or AQMASK mask.

So a change on the apmask triggers an uvevent like this:

KERNEL[490.160396] change /devices/ap (ap)
ACTION=change
DEVPATH=/devices/ap
SUBSYSTEM=ap
APMASK=0xffffffdfffffffffffffffffffffffffffffffffffffffffffffffffffffffff
SEQNUM=13367

and a change on the aqmask looks like this:

KERNEL[283.217642] change /devices/ap (ap)
ACTION=change
DEVPATH=/devices/ap
SUBSYSTEM=ap
AQMASK=0xfbffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
SEQNUM=13348

Only real changes to the masks are processed - the old and
new masks are compared and no action is done if the values
are equal (and thus no uevent). The emit of the uevent is
the very last action done when a mask change is processed.
However, there is no guarantee that all unbind/bind actions
caused by the apmask/aqmask changes are completed when the
apmask/aqmask change uevent is received in userspace.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/zcrypt: handle checkstopped cards with new state

A crypto card may be in checkstopped state. With this
patch this is handled as a new state in the ap card and
ap queue structs. There is also a new card sysfs attribute

/sys/devices/ap/cardxx/chkstop

and a new queue sysfs attribute

/sys/devices/ap/cardxx/xx.yyyy/chkstop

displaying the checkstop state of the card or queue. Please
note that the queue's checkstop state is only a copy of the
card's checkstop state but makes maintenance much easier.

The checkstop state expressed here is the result of an
RC 0x04 (CHECKSTOP) during an AP command, mostly the
PQAP(TAPQ) command which is 'testing' the queue.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt: CEX8S exploitation support

This patch adds CEX8 exploitation support for the AP bus code,
the zcrypt device driver zoo and the vfio device driver.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: enable sysfs attribute scans to force AP bus rescan

This patch switches the sysfs attribute /sys/bus/ap/scans
from read-only to read-write. If there is something written
to this attribute, an AP bus rescan is forced. If an AP
bus scan is triggered this way a debug feature entry line
reports this in /sys/kernel/debug/s390dbf/ap/sprintf.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Jakob Naucke <naucke@linux.ibm.com>
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: notify drivers on config changed and scan complete callbacks

This patch introduces an extension to the ap bus to notify device drivers
when the host AP configuration changes - i.e., adapters, domains or
control domains are added or removed. When an adapter or domain is added to
the host's AP configuration, the AP bus will create the associated queue
devices in the linux sysfs device model. Each new type 10 (i.e., CEX4) or
newer queue device with an APQN that is not reserved for the default device
driver will get bound to the vfio_ap device driver. Likewise, whan an
adapter or domain is removed from the host's AP configuration, the AP bus
will remove the associated queue devices from the sysfs device model. Each
of the queues that is bound to the vfio_ap device driver will get unbound.

With the introduction of hot plug support, binding or unbinding of a
queue device will result in plugging or unplugging one or more queues from
a guest that is using the queue. If there are multiple changes to the
host's AP configuration, it could result in the probe and remove callbacks
getting invoked multiple times. Each time queues are plugged into or
unplugged from a guest, the guest's VCPUs must be taken out of SIE.
If this occurs multiple times due to changes in the host's AP
configuration, that can have an undesirable negative affect on the guest's
performance.

To alleviate this problem, this patch introduces two new callbacks: one to
notify the vfio_ap device driver when the AP bus scan routine detects a
change to the host's AP configuration; and, one to notify the driver when
the AP bus is done scanning. This will allow the vfio_ap driver to do
bulk processing of all affected adapters, domains and control domains for
affected guests rather than plugging or unplugging them one at a time when
the probe or remove callback is invoked. The two new callbacks are:

void (*on_config_changed)(struct ap_config_info *new_config_info,
struct ap_config_info *old_config_info);

This callback is invoked at the start of the AP bus scan
function when it determines that the host AP configuration information
has changed since the previous scan. This is done by storing
an old and current QCI info struct and comparing them. If there is any
difference, the callback is invoked.

void (*on_scan_complete)(struct ap_config_info *new_config_info,
struct ap_config_info *old_config_info);

The on_scan_complete callback is invoked after the ap bus scan is
completed if the host AP configuration data has changed.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: driver callback to indicate resource in use

Introduces a new driver callback to prevent a root user from re-assigning
the APQN of a queue that is in use by a non-default host device driver to
a default host device driver and vice versa. The callback will be invoked
whenever a change to the AP bus's sysfs apmask or aqmask attributes would
result in one or more APQNs being re-assigned. If the callback responds
in the affirmative for any driver queried, the change to the apmask or
aqmask will be rejected with a device busy error.

For this patch, only non-default drivers will be queried. Currently,
there is only one non-default driver, the vfio_ap device driver. The
vfio_ap device driver facilitates pass-through of an AP queue to a
guest. The idea here is that a guest may be administered by a different
sysadmin than the host and we don't want AP resources to unexpectedly
disappear from a guest's AP configuration (i.e., adapters and domains
assigned to the matrix mdev). This will enforce the proper procedure for
removing AP resources intended for guest usage which is to
first unassign them from the matrix mdev, then unbind them from the
vfio_ap device driver.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: function rework based on compiler warning

Slight rework of function __ap_revise_reserved()
because of unused variable warning when build with W=1.
This patch introduces an additional debug feature warning
message when device_reprobe() returns with failure.
However, the return value of __ap_revise_reserved()
is still hard coded to 0 as this is a callback function
to be used together with bus_for_each_dev() and thus
the return value indicates to go on with the
bus_for_each_dev() loop and not apport on a failure
of something within this function.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: new module option ap.useirq

This patch introduces a new AP module option to be able to
control if the ap bus code is using interrupts or not.
By default if the interrupt support is available it is used.
This option makes it possible to disable interrupt use even
when interrupt support is available.

It should be obvious that this option can't magically enable
interrupt support when the hardware or hypervisor layer does
not support AP interrupts.

On the kernel command line use ap.useirq=0 or ap.useirq=1
to disable or enable (that's the default) interrupt use.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt: rework of debug feature messages

This patch reworks all the debug feature invocations to be
more uniform. All invocations now use the macro with the
level already part of the macro name. All messages now start
with %s filled with __func__ (well there are still some
exceptions), and some message text has been shortened or
reworked.

There is no functional code touched with this patch.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: fix kernel doc comments

Get rid of warnings like:

drivers/s390/crypto/ap_bus.c:216: warning:
bad line:
drivers/s390/crypto/ap_bus.c:444:
warning: Function parameter or member 'floating' not described in 'ap_interrupt_handler'

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

s390/ap: fix state machine hang after failure to enable irq

If for any reason the interrupt enable for an ap queue fails the
state machine run for the queue returned wrong return codes to the
caller. So the caller assumed interrupt support for this queue in
enabled and thus did not re-establish the high resolution timer used
for polling. In the end this let to a hang for the user space process
waiting "forever" for the reply.

This patch reworks these return codes to return correct indications
for the caller to re-establish the timer when a queue runs without
interrupt support.

Please note that this is fixing a wrong behavior after a first
failure (enable interrupt support for the queue) failed. However,
looks like this occasionally happens on KVM systems.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: use the common device_driver pointer

The device struct itself already contains a pointer to its driver.
Use this consistently, instead of duplicating it.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/AP: support new dynamic AP bus size limit

This patch provides support for new dynamic AP bus message limit
with the existing zcrypt device driver and AP bus core code.

There is support for a new field 'ml' from TAPQ query. The field
gives if != 0 the AP bus limit for this card in 4k chunk units.
The actual message size limit per card is shown as a new read-only
sysfs attribute. The sysfs attribute

/sys/devices/ap/cardxx/max_msg_size

shows the upper limit in bytes used by the AP bus and zcrypt device
driver for requests and replies send to and received from this card.
Currently up to CEX7 support only max 12kB msg size and thus the field
shows 12288 meaning the upper limit of a valid msg for this card is
12kB. Please note that the usable payload is somewhat lower and
depends on the msg type and thus the header struct which is to be
prepended by the zcrypt dd.

The dispatcher responsible for choosing the right card and queue is
aware of the individual card AP bus message limit. So a request is
only assigned to a queue of a card which is able to handle the size of
the request (e.g. a 14kB request will never go to a max 12kB card).
If no such card is found the ioctl will fail with ENODEV.

The reply buffer held by the device driver is determined by the ml
field of the TAPQ for this card. If a response from the card exceeds
this limit however, the response is not truncated but the ioctl for
this request will fail with errno EMSGSIZE to indicate that the device
driver has dropped the response because it would overflow the buffer
limit.

If the request size does not indicate to the dispatcher that an
adapter with extended limit is to be used, a random card will be
chosen when no specific card is addressed (ANY addressing). This may
result in an ioctl failure when the reply size needs an adapter with
extended limit but the randomly chosen one is not capable of handling
the broader reply size. The user space application needs to use
dedicated addressing to forward such a request only to suitable cards
to get requests like this processed properly.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Tuchscherer <ingo.tuchscherer@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap/zcrypt: notify userspace with online, config and mode info

This patch brings 3 reworked/new uevent changes:
* All AP uevents caused by an ap card or queue device now carry an
additional uevent env value MODE=<accel|cca|ep11>. Here is an
example:
KERNEL[1267.301292] add /devices/ap/card0a (ap)
ACTION=add
DEVPATH=/devices/ap/card0a
SUBSYSTEM=ap
DEVTYPE=ap_card
DEV_TYPE=000D
MODALIAS=ap:t0D
MODE=ep11 <- this is new
SEQNUM=1095
This is true for bind, unbind, add, remove, and change uevents
related to ap card or ap queue devices.
* On a change of the soft online attribute on a zcrypt queue or card
device a new CHANGE uevent is sent with an env value ONLINE=<0|1>.
Example uevent:
KERNEL[613.067531] change /devices/ap/card09/09.0011 (ap)
ACTION=change
DEVPATH=/devices/ap/card09/09.0011
SUBSYSTEM=ap
ONLINE=0 <- this is new
DEVTYPE=ap_queue
DRIVER=cex4queue
MODE=cca
SEQNUM=1070
- On a change of the config state of an zcrypt card device a new
CHANGE uevent is sent with an env value CONFIG=<0|1>.
Example uevent:
KERNEL[876.258680] change /devices/ap/card09 (ap)
ACTION=change
DEVPATH=/devices/ap/card09
SUBSYSTEM=ap
CONFIG=0 <- this is new
DEVTYPE=ap_card
DRIVER=cex4card
DEV_TYPE=000D
MODALIAS=ap:t0D
MODE=cca
SEQNUM=1073
Setting a card config on/off causes the dependent queue devices to
follow the config state change and thus uevents informing about the
config state change for the queue devices are also emitted.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: extend AP change bindings-complete uevent with counter

Userspace udev rules need an indication about the very first AP change
BINDINGS=complete uevent.

So now this uevent is extend with an additional key-value entry
COMPLETECOUNT=<counter>. The very first uevent will show counter=1 and
the following BINDINGS=complete uevents increase this counter by 1.

Here is an example how the very first BINDINGS=complete uevent
looks like:

KERNEL[106.079510] change /devices/ap (ap)
ACTION=change
DEVPATH=/devices/ap
SUBSYSTEM=ap
BINDINGS=complete
COMPLETECOUNT=1
SEQNUM=10686

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: wire up bus->probe and bus->remove

Hijacking the device_driver's probe/remove callbacks for purely
bus-internal logic is a very unconvential construct. Instead just set
up our callbacks in the AP bus struct, and really_probe() will call them
in the same way as before.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: let bus_register() add the AP bus sysfs attributes

Instead of creating the sysfs attributes for the AP bus by hand,
describe them in .bus_groups and let the driver core handle it.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-my: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: ap bus userspace notifications for some bus conditions

This patch adds notifications to userspace for two important
conditions of the ap bus:

I) Initial ap bus scan done. This indicates that the initial
scan of all the ap devices (cards, queues) is complete and
ap devices have been build up for all the hardware found.
This condition is signaled with
1) An ap bus change uevent send to userspace with an environment
key/value pair "INITSCAN=done":
# udevadm monitor -k -p
...
KERNEL[97.830919] change /devices/ap (ap)
ACTION=change
DEVPATH=/devices/ap
SUBSYSTEM=ap
INITSCAN=done
SEQNUM=10421
2) A sysfs attribute /sys/bus/ap/scans which shows the
number of completed ap bus scans done since bus init.
So a value of 1 or greater signals that the initial
ap bus scan is complete.
Note: The initial ap bus scan complete condition is fulfilled
and will be signaled even if there was no ap resource found.

II) APQN driver bindings complete. This indicates that all
APQNs have been bound to an zcrypt or alternate device
driver. Only with the help of an device driver an APQN
can be used for crypto load. So the binding complete
condition is the starting point for user space to be
sure all crypto resources on the ap bus are available
for use.
This condition is signaled with
1) An ap bus change uevent send to userspace with an environment
key/value pair "BINDINGS=complete":
# udevadm monitor -k -p
...
KERNEL[97.830975] change /devices/ap (ap)
ACTION=change
DEVPATH=/devices/ap
SUBSYSTEM=ap
BINDINGS=complete
SEQNUM=10422
2) A sysfs attribute /sys/bus/ap/bindings showing
"<nr of bound apqns>/<total nr of apqns> (complete)"
when all available apqns have been bound to device drivers, or
"<nr of bound apqns>/<total nr of apqns>"
when there are some apqns not bound to an device driver.
Note: The binding complete condition is also fulfilled, when
there are no apqns available to bind any device driver. In
this case the binding complete will be signaled AFTER init
scan is done.
Note: This condition may arise multiple times when after
initial scan modifications on the bindings take place. For
example a manual unbind of an APQN switches the binding
complete condition off. When at a later time the unbound APQNs
are bound with an device driver the binding is (again) complete
resulting in another uevent and marking the bindings sysfs
attribute with '(complete)'.

There is also a new function to be used within the kernel:

int ap_wait_init_apqn_bindings_complete(unsigned long timeout)

Interface to wait for the AP bus to have done one initial ap bus
scan and all detected APQNs have been bound to device drivers.
If these both conditions are not fulfilled, this function blocks
on a condition with wait_for_completion_interruptible_timeout().
If these both conditions are fulfilled (before the timeout hits)
the return value is 0. If the timeout (in jiffies) hits instead
-ETIME is returned. On failures negative return values are
returned to the caller. Please note that further unbind/bind
actions after initial binding complete is through do not cause this
function to block again.

Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: fix ap devices reference counting

With the last rework of the AP bus scan function one get_device() is
missing causing the reference counter to be one instance too
low. Together with binding/unbinding device drivers to an ap device it
may end up in an segfault because the ap device is freed but a device
driver still assumes it's pointer to the ap device is valid:

Unable to handle kernel pointer dereference in virtual kernel address space
Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6803
Fault in home space mode while using kernel ASCE.
Krnl PSW : 0404e00180000000 000000001472f3b6 (klist_next+0x7e/0x180)
R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3
Call Trace:
[<000000001472f3b6>] klist_next+0x7e/0x180
([<000000001472f36a>] klist_next+0x32/0x180)
[<00000000147c14de>] bus_for_each_dev+0x66/0xb8
[<0000000014aab0d4>] ap_scan_adapter+0xcc/0x6c0
[<0000000014aab74a>] ap_scan_bus+0x82/0x140
[<0000000013f3b654>] process_one_work+0x27c/0x478
[<0000000013f3b8b6>] worker_thread+0x66/0x368
[<0000000013f44e32>] kthread+0x17a/0x1a0
[<0000000014af23e4>] ret_from_fork+0x24/0x2c
Kernel panic - not syncing: Fatal exception: panic_on_oops

Fixed by adjusting the reference count with get_device() on the right
place. Also now the device drivers don't need to adjust the ap
device's reference counting any more. This is now done in the ap bus
probe and remove functions.

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Fixes: 4f2fcccdb547 ("s390/ap: add card/queue deconfig state")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: add card/queue deconfig state

This patch adds a new config state to the ap card and queue
devices. This state reflects the response code
0x03 "AP deconfigured" on TQAP invocation and is tracked with
every ap bus scan.

Together with this new state now a card/queue device which
is 'deconfigured' is not disposed any more. However, for backward
compatibility the online state now needs to take this state into
account. So a card/queue is offline when the device is not configured.
Furthermore a device can't get switched from offline to online state
when not configured.

The config state is shown in sysfs at
/sys/devices/ap/cardxx/config
for the card and
/sys/devices/ap/cardxx/xx.yyyy/config
for each queue within each card.
It is a read-only attribute reflecting the negation of the
'AP deconfig' state as it is noted in the AP documents.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: add error response code field for ap queue devices

On AP instruction failures the last response code is now
kept in the struct ap_queue. There is also a new sysfs
attribute showing this field (enabled only on debug kernels).

Also slight rework of the AP_DBF macros to get some more
content into one debug feature message line.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: split ap queue state machine state from device state

The state machine for each ap queue covered a mixture of
device states and state machine (firmware queue state) states.

This patch splits the device states and the state machine
states into two different enums and variables. The major
state is the device state with currently these values:

AP_DEV_STATE_UNINITIATED - fresh and virgin, not touched
AP_DEV_STATE_OPERATING - queue dev is working normal
AP_DEV_STATE_SHUTDOWN - remove/unbind/shutdown in progress
AP_DEV_STATE_ERROR - device is in error state

only when the device state is > UNINITIATED the state machine
is run. The state machine represents the states of the firmware
queue:

AP_SM_STATE_RESET_START - starting point, reset (RAPQ) ap queue
AP_SM_STATE_RESET_WAIT - reset triggered, waiting to be finished
if irqs enabled, set up irq (AQIC)
AP_SM_STATE_SETIRQ_WAIT - enable irq triggered, waiting to be
finished, then go to IDLE
AP_SM_STATE_IDLE - queue is operational but empty
AP_SM_STATE_WORKING - queue is operational, requests are stored
and replies may wait for getting fetched
AP_SM_STATE_QUEUE_FULL - firmware queue is full, so only replies
can get fetched

For debugging each ap queue shows a sysfs attribute 'states' which
displays the device and state machine state and is only available
when the kernel is build with CONFIG_ZCRYPT_DEBUG enabled.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: remove unnecessary spin_lock_init()

The spinlock ap_poll_timer_lock is initialized statically. It is
unnecessary to initialize by spin_lock_init().

Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD()

This converts all the existing DECLARE_TASKLET() (and ...DISABLED)
macros with DECLARE_TASKLET_OLD() in preparation for refactoring the
tasklet callback type. All existing DECLARE_TASKLET() users had a "0"
data argument, it has been removed here as well.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kees Cook <keescook@chromium.org>

s390/ap: rework crypto config info and default domain code

Rework of the QCI crypto info and how it is used.
This is only a internal rework but does not affect the way
how the ap bus acts with ap card and queue devices and
domain handling.

Tested on z15, z14, z12 (QCI support) and z196 (no QCI support).

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

s390/ap: rename and clarify ap state machine related stuff

There is a state machine held for each ap queue device.
The states and functions related to this where somethimes
noted with _sm_ somethimes without. This patch clarifies
and renames all the ap queue state machine related functions,
enums and defines to have a _sm_ in the name.

There is no functional change coming with this patch - it's
only beautifying code.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/ap: introduce new ap function ap_get_qdev()

Provide a new interface function to be used by the ap drivers:
struct ap_queue *ap_get_qdev(ap_qid_t qid);
Returns ptr to the struct ap_queue device or NULL if there
was no ap_queue device with this qid found. When something is
found, the reference count of the embedded device is increased.
So the caller has to decrease the reference count after use
with a call to put_device(&aq->ap_dev.device).

With this patch also the ap_card_list is removed from the
ap core code and a new hashtable is introduced which stores
hnodes of all the ap queues known to the ap bus.

The hashtable approach and a first implementation of this
interface comes from a previous patch from
Anthony Krowiak and an idea from Halil Pasic.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Suggested-by: Tony Krowiak <akrowiak@linux.ibm.com>
Suggested-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: remove power management code from ap bus and drivers

The s390 power management support has been removed. So the
api registration and the suspend and resume callbacks and
all the code related to this for the ap bus and the ap drivers
is removed with this patch.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt: use fallthrough;

Convert the various uses of fallthrough comments to fallthrough;

Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe.com/

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/ap: Remove ap device suspend and resume callbacks

With the removal of the s390 hibernate support the suspend and
resume callbacks for the ap devices are not needed any more.

This patch removes the callbacks and the ap bus' registration
struct for the power management.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt: replace snprintf/sprintf with scnprintf

snprintf() may not always return the correct size of used bytes but
instead the length the resulting string would be if it would fit into
the buffer. So scnprintf() is the function to use when the real length
of the resulting string is needed.

Replace all occurrences of snprintf() with scnprintf() where the return
code is further processed. Also find and fix some occurrences where
sprintf() was used.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt: move ap device reset from bus to driver code

This patch moves the reset invocation of an ap device when
fresh detected from the ap bus to the probe() function of
the driver responsible for this device.

The virtualisation of ap devices makes it necessary to
remove unconditioned resets on fresh appearing apqn devices.
It may be that such a device is already enabled for guest
usage. So there may be a race condition between host ap bus
and guest ap bus doing the reset. This patch moves the
reset from the ap bus to the zcrypt drivers. So if there
is no zcrypt driver bound to an ap device - for example
the ap device is bound to the vfio device driver - the
ap device is untouched passed to the vfio device driver.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt: CEX7S exploitation support

This patch adds CEX7 exploitation support for the AP bus code,
the zcrypt device driver zoo and the vfio device driver.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

s390/zcrypt: remove the exporting of ap_query_configuration

The function ap_query_configuration is declared static and marked
EXPORT_SYMBOL, which is at best an odd combination. Because the
function is not used outside of the drivers/s390/crypto/ap_bus.c
file it is defined in, this commit removes the EXPORT_SYMBOL() marking.

Link: http://lkml.kernel.org/r/20190709122507.11158-1-efremov@linux.com
Fixes: f1b0a4343c41 ("s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h.")
Fixes: 050349b5b71d ("s390/zcrypt: externalize AP config info query")
Signed-off-by: Denis Efremov <efremov@linux.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

bus_find_device: Unify the match callback with class_find_device

There is an arbitrary difference between the prototypes of
bus_find_device() and class_find_device() preventing their callers
from passing the same pair of data and match() arguments to both of
them, which is the const qualifier used in the prototype of
class_find_device(). If that qualifier is also used in the
bus_find_device() prototype, it will be possible to pass the same
match() callback function to both bus_find_device() and
class_find_device(), which will allow some optimizations to be made in
order to avoid code duplication going forward. Also with that, constify
the "data" parameter as it is passed as a const to the match function.

For this reason, change the prototype of bus_find_device() to match
the prototype of class_find_device() and adjust its callers to use the
const qualifier in accordance with the new prototype of it.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Kershner <david.kershner@unisys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Sebastian Ott <sebott@linux.ibm.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Cc: rafael@kernel.org
Acked-by: Corey Minyard <minyard@acm.org>
Acked-by: David Kershner <david.kershner@unisys.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

s390/zcrypt: Fix wrong dispatching for control domain CPRBs

The zcrypt device driver does not handle CPRBs which address
a control domain correctly. This fix introduces a workaround:
The domain field of the request CPRB is checked if there is
a valid domain value in there. If this is true and the value
is a control only domain (a domain which is enabled in the
crypto config ADM mask but disabled in the AQM mask) the
CPRB is forwarded to the default usage domain. If there is
no default domain, the request is rejected with an ENODEV.

This fix is important for maintaining crypto adapters. For
example one LPAR can use a crypto adapter domain ('Control
and Usage') but another LPAR needs to be able to maintain
this adapter domain ('Control'). Scenarios like this did
not work properly and the patch enables this.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/airq: recognize directed interrupts

Add an extra parameter for airq handlers to recognize
floating vs. directed interrupts.

Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

zcrypt: handle AP Info notification from CHSC SEI command

The current AP bus implementation periodically polls the AP configuration
to detect changes. When the AP configuration is dynamically changed via the
SE or an SCLP instruction, the changes will not be reflected to sysfs until
the next time the AP configuration is polled. The CHSC architecture
provides a Store Event Information (SEI) command to make notification of an
AP configuration change. This patch introduces a handler to process
notification from the CHSC SEI command by immediately kicking off an AP bus
scan-after-event.

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.ibm.com>
Reviewed-by: Harald Freudenberger <FREUDE@de.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: revisit ap device remove procedure

Working with the vfio-ap driver let to some revisit of the way
how an ap (queue) device is removed from the driver.
With the current implementation all the cleanup was done before
the driver even got notified about the removal. Now the ap
queue removal is done in 3 steps:
1) A preparation step, all ap messages within the queue
are flushed and so the driver does 'receive' them.
Also a new state AP_STATE_REMOVE assigned to the queue
makes sure there are no new messages queued in.
2) Now the driver's remove function is invoked and the
driver should do the job of cleaning up it's internal
administration lists or whatever. After 2) is done
it is guaranteed, that the driver is not invoked any
more. On the other hand the driver has to make sure
that the APQN is not accessed any more after step 2
is complete.
3) Now the ap bus code does the job of total cleanup of the
APQN. A reset with zero is triggered and the state of
the queue goes to AP_STATE_UNBOUND.
After step 3) is complete, the ap queue has no pending
messages and the APQN is cleared and so there are no
requests and replies lingering around in the firmware
queue for this APQN. Also the interrupts are disabled.

After these remove steps the ap queue device may be assigned
to another driver.

Stress testing this remove/probe procedure showed a problem with the
correct module reference counting. The actual receive of an reply in
the driver is done asynchronous with completions. So with a driver
change on an ap queue the message flush triggers completions but the
threads waiting for the completions may run at a time where the queue
already has the new driver assigned. So the module_put() at receive
time needs to be done on the driver module which queued the ap
message. This change is also part of this patch.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: use new state UNBOUND during queue driver rebind

When an alternate driver (vfio-ap) has bound an ap queue and this
binding is revised the ap queue device is in an intermittent
state not bound to any driver. The internal state variable
covered this with the state AP_STATE_BORKED which is also used to
reflect broken devices. When now an ap bus scan runs such a
device is destroyed and on the next scan reconstructed.

So a stress test with high frequency switching the queue driver
between the default and the vfio-ap driver hit this gap and the
queue was removed until the next ap bus scan. This fix now
introduces another state for the in-between condition for a queue
momentary not bound to a driver and so the ap bus scan function
skips this device instead of removing it.

Also some very slight but maybe helpful debug feature messages
come with this patch - in particular a message showing that a
broken card/queue device will get removed.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Ingo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: fix specification exception on z196 during ap probe

The older machines don't have the QCI instruction available.
With support for up to 256 crypto cards the probing of each
card has been extended to check card ids from 0 up to 255.
For machines with QCI support there is a filter limiting the
range of probed cards. The older machines (z196 and older)
don't have this filter and so since support for 256 cards is
in the driver all cards are probed. However, these machines
also require to have the card id fit into 6 bits. Exceeding
this limit results in a specification exception which happens
on every kernel startup even when there is no crypto configured
and used at all.

This fix limits the range of probed crypto cards to 64 if
there is no QCI instruction available to obey to the older
ap architecture and so fixes the specification exceptions
on z196 machines.

Cc: stable@vger.kernel.org # v4.17+
Fixes: af4a72276d49 ("s390/zcrypt: Support up to 256 crypto adapters.")
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: rework ap scan bus code

Rework of the AP bus scan code. The ap_scan_bus() function
is large, so this patch splits the code by introducing a new
new function _ap_scan_bus_adapter() which deals with just
one adapter and thus reduces the scan function code complexity.

Now the AP bus scan can handle a type change of an crypto
adapter on the fly (e.g. from CEX5 to CEX6). This may be
the case with newer versions of zVM where the card may
be pure virtual and a type change is just one click.
However a type or function change requires to unregister
all queue devices and the card device and re-register them.

Comments around the AP bus scan code have been added and/or
improved to provide some hopefully useful hints about what
the code is actually doing.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: reinit ap queue state machine during device probe

Until the vfio-ap driver came into live there was a well known
agreement about the way how ap devices are initialized and their
states when the driver's probe function is called.

However, the vfio device driver when receiving an ap queue device does
additional resets thereby removing the registration for interrupts for
the ap device done by the ap bus core code. So when later the vfio
driver releases the device and one of the default zcrypt drivers takes
care of the device the interrupt registration needs to get
renewed. The current code does no renew and result is that requests
send into such a queue will never see a reply processed - the
application hangs.

This patch adds a function which resets the aq queue state machine for
the ap queue device and triggers the walk through the initial states
(which are reset and registration for interrupts). This function is
now called before the driver's probe function is invoked.

When the association between driver and device is released, the
driver's remove function is called. The current implementation calls a
ap queue function ap_queue_remove(). This invokation has been moved to
the ap bus function to make the probe / remove pair for ap bus and
drivers more symmetric.

Fixes: 7e0bdbe5c21c ("s390/zcrypt: AP bus support for alternate driver(s)")
Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewd-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewd-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: add ap_adapter_mask sysfs attribute

This patch provides a new sysfs attribute file
/sys/bus/ap/ap_adapter_mask. This read-only attribute
refrects the apm field as it is found in the PQAP(QCI)
crypto info.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: multiple zcrypt device nodes support

This patch is an extension to the zcrypt device driver to provide,
support and maintain multiple zcrypt device nodes. The individual
zcrypt device nodes can be restricted in terms of crypto cards,
domains and available ioctls. Such a device node can be used as a
base for container solutions like docker to control and restrict
the access to crypto resources.

The handling is done with a new sysfs subdir /sys/class/zcrypt.
Echoing a name (or an empty sting) into the attribute "create" creates
a new zcrypt device node. In /sys/class/zcrypt a new link will appear
which points to the sysfs device tree of this new device. The
attribute files "ioctlmask", "apmask" and "aqmask" in this directory
are used to customize this new zcrypt device node instance. Finally
the zcrypt device node can be destroyed by echoing the name into
/sys/class/zcrypt/destroy. The internal structs holding the device
info are reference counted - so a destroy will not hard remove a
device but only marks it as removable when the reference counter drops
to zero.

The mask values are bitmaps in big endian order starting with bit 0.
So adapter number 0 is the leftmost bit, mask is 0x8000... The sysfs
attributes accept 2 different formats:
* Absolute hex string starting with 0x like "0x12345678" does set
the mask starting from left to right. If the given string is shorter
than the mask it is padded with 0s on the right. If the string is
longer than the mask an error comes back (EINVAL).
* Relative format - a concatenation (done with ',') of the
terms +<bitnr>[-<bitnr>] or -<bitnr>[-<bitnr>]. <bitnr> may be any
valid number (hex, decimal or octal) in the range 0...255. Here are
some examples:
"+0-15,+32,-128,-0xFF"
"-0-255,+1-16,+0x128"
"+1,+2,+3,+4,-5,-7-10"

A simple usage examples:

# create new zcrypt device 'my_zcrypt':
echo "my_zcrypt" >/sys/class/zcrypt/create
# go into the device dir of this new device
echo "my_zcrypt" >create
cd my_zcrypt/
ls -l
total 0
-rw-r--r-- 1 root root 4096 Jul 20 15:23 apmask
-rw-r--r-- 1 root root 4096 Jul 20 15:23 aqmask
-r--r--r-- 1 root root 4096 Jul 20 15:23 dev
-rw-r--r-- 1 root root 4096 Jul 20 15:23 ioctlmask
lrwxrwxrwx 1 root root 0 Jul 20 15:23 subsystem -> ../../../../class/zcrypt
...
# customize this zcrypt node clone
# enable only adapter 0 and 2
echo "0xa0" >apmask
# enable only domain 6
echo "+6" >aqmask
# enable all 256 ioctls
echo "+0-255" >ioctls
# now the /dev/my_zcrypt may be used
# finally destroy it
echo "my_zcrypt" >/sys/class/zcrypt/destroy

Please note that a very similar 'filtering behavior' also applies to
the parent z90crypt device. The two mask attributes apmask and aqmask
in /sys/bus/ap act the very same for the z90crypt device node. However
the implementation here is totally different as the ap bus acts on
bind/unbind of queue devices and associated drivers but the effect is
still the same. So there are two filters active for each additional
zcrypt device node: The adapter/domain needs to be enabled on the ap
bus level and it needs to be active on the zcrypt device node level.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: enable AP bus scan without a valid default domain

The AP bus scan is aborted before doing anything worth mentioning if
ap_select_domain() fails, e.g. if the ap_rights.aqm mask is all zeros.
As the result of this the ap bus fails to manage (e.g. create and
register) devices like it is supposed to.

Let us make ap_scan_bus() work even if ap_select_domain() can't select a
default domain. Let's also make ap_select_domain() return void, as there
are no more callers interested in its return value.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Michael Mueller <mimu@linux.ibm.com>
Fixes: 7e0bdbe5c21c "s390/zcrypt: AP bus support for alternate driver(s)"
[freude@linux.ibm.com: title and patch header slightly modified]
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: remove VLA usage from the AP bus

The use of variable length arrays on the stack is deprecated.
git commit 3d8f60d38e249f989a7fca9c2370c31c3d5487e1
"s390/zcrypt: hex string mask improvements for apmask and aqmask."
added three new VLA arrays. Remove them again.

Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: hex string mask improvements for apmask and aqmask.

The sysfs attributes /sys/bus/ap/apmask and /sys/bus/ap/aqmask
and the kernel command line arguments ap.apm and ap.aqm get
an improvement of the value parsing with this patch:

The mask values are bitmaps in big endian order starting with bit 0.
So adapter number 0 is the leftmost bit, mask is 0x8000... The sysfs
attributes and the kernel command line accept 2 different formats:
- Absolute hex string starting with 0x like "0x12345678" does set
the mask starting from left to right. If the given string is shorter
than the mask it is padded with 0s on the right. If the string is
longer than the mask an error comes back (EINVAL).
- Relative format - a concatenation (done with ',') of the terms
+<bitnr>[-<bitnr>] or -<bitnr>[-<bitnr>]. <bitnr> may be any
valid number (hex, decimal or octal) in the range 0...255.
Here are some examples:
"+0-15,+32,-128,-0xFF"
"-0-255,+1-16,+0x128"

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: AP bus support for alternate driver(s)

The current AP bus, AP devices and AP device drivers implementation
uses a clearly defined mapping for binding AP devices to AP device
drivers. So for example a CEX6C queue will always be bound to the
cex4queue device driver.

The Linux Device Driver model has no sensitivity for more than one
device driver eligible for one device type. If there exist more than
one drivers matching to the device type, simple all drivers are tried
consecutively. There is no way to determine and influence the probing
order of the drivers.

With KVM there is a need to provide additional device drivers matching
to the very same type of AP devices. With a simple implementation the
KVM drivers run in competition to the regular drivers. Whichever
'wins' a device depends on build order and implementation details
within the common Linux Device Driver Model and is not
deterministic. However, a userspace process could figure out which
device should be bound to which driver and sort out the correct
binding by manipulating attributes in the sysfs.

If for security reasons a AP device must not get bound to the 'wrong'
device driver the sorting out has to be done within the Linux kernel
by the AP bus code. This patch modifies the behavior of the AP bus
for probing drivers for devices in a way that two sets of drivers are
usable. Two new bitmasks 'apmask' and 'aqmask' are used to mark a
subset of the APQN range for 'usable by the ap bus and the default
drivers' or 'not usable by the default drivers and thus available for
alternate drivers like vfio-xxx'. So an APQN which is addressed by
this masking only the default drivers will be probed. In contrary an
APQN which is not addressed by the masks will never be probed and
bound to default drivers but onny to alternate drivers.

Eventually the two masks give a way to divide the range of APQNs into
two pools: one pool of APQNs used by the AP bus and the default
drivers and thus via zcrypt drivers available to the userspace of the
system. And another pool where no zcrypt drivers are bound to and
which can be used by alternate drivers (like vfio-xxx) for their
needs. This division is hot-plug save and makes sure a APQN assigned
to an alternate driver is at no time somehow exploitable by the wrong
party.

The two masks are located in sysfs at /sys/bus/ap/apmask and
/sys/bus/ap/aqmask. The mask syntax is exactly the same as the
already existing mask attributes in the /sys/bus/ap directory (for
example ap_usage_domain_mask and ap_control_domain_mask).

By default all APQNs belong to the ap bus and the default drivers:

cat /sys/bus/ap/apmask
0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
cat /sys/bus/ap/aqmask
0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff

The masks can be changed at boot time with the kernel command line
like this:

... ap.apmask=0xffff ap.aqmask=0x40

This would give these two pools:

default drivers pool: adapter 0 - 15, domain 1
alternate drivers pool: adapter 0 - 15, all but domain 1
adapter 16-255, all domains

The sysfs attributes for this two masks are writeable and an
administrator is able to reconfigure the assignements on the fly by
writing new mask values into. With changing the mask(s) a revision of
the existing queue to driver bindings is done. So all APQNs which are
bound to the 'wrong' driver are reprobed via kernel function
device_reprobe() and thus the new correct driver will be assigned with
respect of the changed apmask and aqmask bits.

The mask values are bitmaps in big endian order starting with bit 0.
So adapter number 0 is the leftmost bit, mask is 0x8000... The sysfs
attributes accept 2 different formats:
- Absolute hex string starting with 0x like "0x12345678" does set
the mask starting from left to right. If the given string is shorter
than the mask it is padded with 0s on the right. If the string is
longer than the mask an error comes back (EINVAL).
- '+' or '-' followed by a numerical value. Valid examples are "+1",
"-13", "+0x41", "-0xff" and even "+0" and "-0". Only the addressed
bit in the mask is switched on ('+') or off ('-').

This patch will also be the base for an upcoming extension to the
zcrypt drivers to be able to provide additional zcrypt device nodes
with filtering based on ap and aq masks.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: code beautify

Code beautify by following most of the checkpatch suggestions:
- SPDX license identifier line complains by checkpatch
- missing space or newline complains by checkpatch
- octal numbers for permssions complains by checkpatch
- renaming of static sysfs functions complains by checkpatch
- fix of block comment complains by checkpatch
- fix printf like calls where function name instead of %s __func__
was used
- __packed instead of __attribute__((packed))
- init to zero for static variables removed
- use of DEVICE_ATTR_RO and DEVICE_ATTR_RW macros

No functional code changes or API changes!

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: fix ap_instructions_available() returncodes

During review of KVM patches it was complained that the
ap_instructions_available() function returns 0 if AP
instructions are available and -ENODEV if not. The function
acts like a boolean function to check for AP instructions
available and thus should return 0 on failure and != 0 on
success. Changed to the suggested behaviour and adapted
the one and only caller of this function which is the ap
bus core code.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/ap_bus: replace PTR_RET with PTR_ERR_OR_ZERO

PTR_RET is deprecated, use PTR_ERR_OR_ZERO instead.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h.

Move all the inline functions from the ap bus header
file ap_asm.h into the in-kernel api header file
arch/s390/include/asm/ap.h so that KVM can make use
of all the low level AP functions.

Signed-off-by: Harald Freudenberger <freude@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Make ap init functions static.

The ap init functions ap_module_init and ap_debug_init are
only used within ap_bus.c. Make these functions static and
do not declare them in any header file any more.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: assume diag308 set always works

diag308 set has been available for many machine generations, and
alternative reipl code paths has not been exercised and seems to be
broken without noticing for a while now. So, cleaning up all obsolete
reipl methods except currently used ones, assuming that diag308 set
always works.

Also removing not longer needed reset callbacks.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: remove unused functions and declarations

The AP bus code is not available as kernel module any more.
There was some leftover code dealing with kernel module
exit which has been removed with this patch.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: crypto: Remove redundant license text

Now that the SPDX tag is in all drivers/s390/crypto/ files, that
identifies the license in a specific and legally-defined manner. So the
extra GPL text wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Harald Freudenberger <freude@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.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>

s390: crypto: 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/crypto/ 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: Harald Freudenberger <freude@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.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>

s390/ap_bus: 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: Harald Freudenberger <freude@de.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/zcrypt: Rework struct ap_qact_ap_info.

The ap_qact_ap_info struct can get more easy handled when the fields
in there can be accessed by their names but also the struct as a whole
with just an unsigned long value. This patch reworks this struct to be
a union and adapt the using code accordingly.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/zcrypt: Introduce QACT support for AP bus devices.

This patch introduces a new ap_qact() function which
exploits the PQAP(QACT) subfunction. QACT is a new
interface to Query the Ap Compatilibity Type based
on a given AP qid, type, mode and version.

Based on this new function the AP bus scan code is
slightly reworked to use this new interface for
querying the compatible type for each new AP queue
device detected. So new and unknown devices can
get automatically mapped to a compatible type and
handled without the need for toleration patches
for every new hardware.

The currently highest known hardware is CEX6S.
With this patch a possible successor can get
queried for a combatible type known by the device
driver without the need for an toleration patch.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: externalize AP config info query

KVM has a need to fetch the crypto configuration information
as it is returned by the PQAP(QCI) instruction. This patch
introduces a new API ap_query_configuration() which provides
this info in a handy way for the caller.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: externalize test AP queue

Under certain specified conditions, the Test AP Queue (TAPQ)
subfunction of the Process Adjunct Processor Queue (PQAP) instruction
will be intercepted by a guest VM. The guest VM must have a means for
executing the intercepted instruction.

The vfio_ap driver will provide an interface to execute the
PQAP(TAPQ) instruction subfunction on behalf of a guest VM.
The code for executing the AP instructions currently resides in the
AP bus. This patch refactors the AP bus code to externalize access
to the PQAP(TAPQ) instruction subfunction to make it available to
the vfio_ap driver.

Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Rework ap init in case of out of range domain param.

When a out of range domain parameter was given, the init function
returned with -EINVAL and the driver was not operational. As the
driver is statically build into the kernel and is able to work
with multiple domains anyway the init function should continue.
Now the user has a chance to write a new default domain value
via sysfs attribute file. Also added two new dbf debug messages
related to the domain value handling.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Fix blocking queue device after unbind/bind.

When the association between a queue device and the
driver is released via unbind and later re-associated
the queue device was not operational any more. Reason
was a wrong administration of the card/queue lists
within the ap device driver.

This patch introduces revised card/queue list handling
within the ap device driver: when an ap device is
detected it is initial not added to the card/queue list
any more. With driver probe the card device is added to
the card list/the queue device is added to the queue list
within a card. With driver remove the device is removed
from the card/queue list. Additionally there are some
situations within the ap device live where the lists
need update upon card/queue device release (for example
device hot unplug or suspend/resume).

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Cleanup leftover module code.

The AP bus code is not buildable as kernel module any more.
Commit 5fe38260d083 ("s390/zcrypt: make ap_bus explicitly
non-modular") leaves one now unused function which gets
removed with this patch.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: make ap_bus explicitly non-modular

The Makefile in drivers/s390 has:

obj-y += cio/ block/ char/ crypto/ net/ scsi/ virtio/

and the Makefile in crypto/ has:

ap-objs := ap_bus.o ap_card.o ap_queue.o

meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Also note that MODULE_ALIAS is a no-op for non-module builds.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

We replace module.h with moduleparam.h since the file does declare
some module parameters even though it is not modular itself.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Removed unneeded debug feature directory creation.

The ap bus code and the zcrypt api had invocations to the
debug feature debugfs_create_dir() call but never populated
these directories in any way. Removed this unneeded code.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

ktime: Cleanup ktime_set() usage

ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>

s390/zcrypt: Rework debug feature invocations.

Rework the debug feature calls and initialization. There
are now two debug feature entries used by the zcrypt code.
The first is 'ap' with all the AP bus related stuff and the
second is 'zcrypt' with all the zcrypt and devices and
driver related entries. However, there isn't much traffic on
both debug features. The ap bus code emits only some debug
info and for zcrypt devices on appearance and disappearance
there is an entry written.

The new dbf invocations use the sprintf buffer layout,
whereas the old implementation used the ascii dbf buffer.
There are now 5*8=40 bytes used for each entry, resulting in
5 parameters per call. As the sprintf buffer needs a format
string the first parameter provides this and so up to 4 more
parameters can be used. Alltogehter the new layout should be
much more human readable for customers and test.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Fix ap_max_domain_id for older machine types

According to the system architecture the current implementation
requires the presence of the N bit in GR2 in the TAPQ response
field to validate the max. number of domains (Nd).
Older machine types don't have this N bit, hence the max. domain
field was ignored.

Before the N bit was introduced the maximum number of domain was
a constant value of 15. So set this value in case of N bit absence.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Correct function bits for CEX2x and CEX3x cards.

For the older CEX2x and CEX3x cards the function bits returned
by TAPQ do not reflect the functions of the card. Instead the
functionality is implicit by the type of the card. The reworked
zcrypt requires to have the function bits set correct, so this
patch fixes this. The queue selection is not only based on these
function bits but also on function pointers set by the individual
drivers.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: add multi domain support

Currently the ap infrastructure only supports one domain at a time.
This feature extends the generic cryptographic device driver to
support multiple cryptographic domains simultaneously.

There are now card and queue devices on the AP bus with independent
card and queue drivers. The new /sys layout is as follows:

/sys/bus/ap
devices
<xx>.<yyyy> -> ../../../devices/ap/card<xx>/<xx>.<yyyy>
...
card<xx> -> ../../../devices/ap/card<xx>
...
drivers
<drv>card
card<xx> -> ../../../../devices/ap/card<xx>
<drv>queue
<xx>.<yyyy> -> ../../../../devices/ap/card<xx>/<xx>.<yyyy>
...

/sys/devices/ap
card<xx>
<xx>.<yyyy>
driver -> ../../../../bus/ap/drivers/<zzz>queue
...
driver -> ../../../bus/ap/drivers/<drv>card
...

The two digit <xx> field is the card number, the four digit <yyyy>
field is the queue number and <drv> is the name of the device driver,
e.g. "cex4".

For compatability /sys/bus/ap/card<xx> for the old layout has to exist,
including the attributes that used to reside there.

With additional contributions from Harald Freudenberger and
Martin Schwidefsky.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: get rid of ap_poll_requests

The poll thread of the AP bus is burning CPU while waiting for
crypto requests to complete. We can as well burn a few more cycles
in the poll thread to check if there are pending requests and
remove the atomic operations with the ap_poll_requests.
This improves the code if the machine has adapter interrupts.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: header for the AP inline assmblies

Move the inline assemblies for the AP bus into a separate header file.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Move the ap bus into kernel

Move the ap bus into the kernel and make it general available.
Additionally include the message types and the API layer as a
preparation for the workload management facility.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Introduce CEX6 toleration

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Convert to PM ops

Switch the zcrypt bus from legacy suspend/resume callbacks to dev_pm_ops.
The conversion is straight forward with the help of SIMPLE_DEV_PM_OPS().
The new dev_pm_ops based version is functionally equivalent to the legacy
callbacks version.

This will allow to eventually remove support for legacy suspend/resume
callbacks from the kernel altogether.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: fix possible memory leak in ap_module_init()

ap_configuration is malloced in ap_module_init() and should be freed
before leaving from the error handling cases, otherwise it may cause
memory leak.

Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Fix zcrypt suspend/resume behavior

The device suspend call triggers all ap devices to fetch potentially
available response messages from the queues. Therefore the
corresponding zcrypt device, that is allocated asynchronously after
ap device probing, needs to be fully prepared. This race condition
could lead to uninitialized response buffers while trying to read
from the queues.

Introduce a new callback within the ap layer to get noticed when a
zcrypt device is fully prepared. Additional checks prevent reading
from devices that are not fully prepared.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/crypto: use basic blocks for ap bus inline assemblies

Use only simple inline assemblies which consist of a single basic
block if the register asm construct is being used.

Otherwise gcc would generate broken code if the compiler option
--sanitize-coverage=trace-pc would be used.

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

s390: make couple of variables and functions static

copy_oldmem_user() and ap_jumptable are private to the files they are
being used in. Therefore make them static.

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

s390/zcrypt: Fix AP queue handling if queue is full

When the AP queue depth of requests was reached additional requests
have been ignored. These request are stuck in the request queue.

The AP queue handling now push the next waiting request into the
queue after fetching a previous serviced and finished reply.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Fix kernel crash on systems without AP bus support

On systems without AP bus (e.g. KVM) the kernel crashes during init
calls when zcrypt is built-in:

kernel BUG at drivers/base/driver.c:153!
illegal operation: 0001 ilc:1 [#1] SMP
Modules linked in:
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.2.0+ #221
task: 0000000010a40000 ti: 0000000010a48000 task.ti:0000000010a48000
Krnl PSW : 0704c00180000000 0000000000592bd6(driver_register+0x106/0x140)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3
0000000000000012 0000000000000000 0000000000c45328 0000000000c44e30
00000000009ef63c 000000000067f598 0000000000cf3c58 0000000000000000
000000000000007b 0000000000cb1030 0000000000000002 0000000000000000
0000000000ca8580 0000000010306700 00000000001001d8 0000000010a4bd88
Krnl Code: 0000000000592bc6: f0b00004ebcf srp 4(12,%r0),3023(%r14),0
0000000000592bcc: f0a0000407f4 srp 4(11,%r0),2036,0
#0000000000592bd2: a7f40001 brc 15,592bd4
>0000000000592bd6: e330d0000004 lg %r3,0(%r13)
0000000000592bdc: c0200021edfd larl %r2,9d07d6
0000000000592be2: c0e500126d8f brasl %r14,7e0700
0000000000592be8: e330d0080004 lg %r3,8(%r13)
0000000000592bee: a7f4ffab brc 15,592b44
Call Trace:
([<00000000001001c8>] do_one_initcall+0x90/0x1d0)
[<0000000000c6dd34>] kernel_init_freeable+0x1e4/0x2a0
[<00000000007db53a>] kernel_init+0x2a/0x120
[<00000000007e8ece>] kernel_thread_starter+0x6/0xc
[<00000000007e8ec8>] kernel_thread_starter+0x0/0xc
Last Breaking-Event-Address:
[<0000000000592bd2>] driver_register+0x102/0x140

When zcrypt is built as a module, the module loader ensures that the
driver modules cannot be loaded if the AP bus module returns an error
during initialisation. But if zcrypt and the driver are built-in, the
driver is getting initialised even if the AP bus initialisation
failed. The driver invokes ap_driver_register() during initialisation,
which then causes operations on uninitialised data structures to be
performed.

Explicitly protect ap_driver_register() by introducing an
"initialised" flag that gets set iff the AP bus initialisation was
successful. When the AP bus initialisation failed,
ap_driver_register() will error out with -ENODEV, causing the driver
initialisation to fail as well.

Test results:
1. Inside KVM (no AP bus), zcrypt built-in

Boots. /sys/bus/ap not present (expected).

2. Inside KVM (no AP bus), zcrypt as module

Boots. Loading zcrypt_cex4 fails because loading ap_bus fails
(expected).

3. On LPAR with CEX5, zcrypt built-in

Boots. /sys/bus/ap/devices/card* present but .../card*/type missing
(i.e. zcrypt_device_register() fails, unrelated issue).

4. On LPAR with CEX5, zcrypt as module

Boots. Loading zcrypt_cex4 successful,
/sys/bus/ap/devices/card*/type present. No further testing
(user-space functionality) was done.

Signed-off-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: use system work queue for ap_scan_bus

There is a system work queue system_long_wq for long running work.
Use this work queue for the AP bus scan loop.

Reviewd-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: remove support for PCICC and PCICA cards

Remove the code for really old crypt cards, PCICC and PCICA.
These cards have been out of service for several years.

Reviewd-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: introduce state machine for the AP bus

Replace the two fields 'unregistered' and 'reset' with a device
state with 5 possible values. Introduce two events for the AP devices,
device poll and device timeout. With the state machine it is easier
to deal with device initialization and suspend/resume. Device polling
is simpler as well, the arkane 'flags' passing is gone.

Reviewd-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: use explicit return code for flushed requests

If a AP device is removed while messages are still pending, the requests
are cancelled by calling the message receive function with an error pointer
for the reply. The message type receive handler recognize this and create
a fake hardware error TYPE82_RSP_CODE / REP82_ERROR_MACHINE_FAILURE.
The message with the hardware error then causes a printk and a return
code of -EAGAIN.

Replace the intricate scheme with an explicit return code for this sitation
and avoid the error message.

Reviewd-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: cleanup AP bus timer code

Set the configuration timer at the end of the ap_scan_bus function.
Make use of setup_timer and remove some unnecessary add_timer, mod_timer
and del_timer_sync calls. Replace the complicated timer_pending, mod_timer
and add_timer code in ap_config_time_store with a simple mod_timer.

Reviewd-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: fix suspend/resume of AP bus devices

If there are no devices on the AP bus there will not be a single
call to the per-device ap_bus_suspend function. Even worse,
there will not be a call to the per-device ap_bus_resume either
and the AP will fail so resume correctly.

Introduce a bus specific dev_pm_ops to suspend / resume the AP
bus related things. While we are at it, simplify the power management
code of the AP bus.

Reviewd-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: fix device unregister race

The ap_queue_messsage function will call device_unregister if the
unregistered field of the device has been set while trying to queue
a message. This races with other device_unregister calls, e.g. from
the ap_scan_bus. Remove the call to device_unregister from
ap_queue_message and let ap_scan_bus deal with it.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: fix memory leak with ap configuration data

The ap_query_configuration function allocates the ap_config_info
structure, but there is no code to free the structure.
Allocate the structure in the module_init function and free it
again in module_exit.

While we are at it simplify a few functions in regard to the
ap configuration data.

Reviewed-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: remove duplicate low level functions

ap_test_queue, ap_query_facilities, __ap_query_functions all use
the same PQAP(TAPQ) command. Consolidate the three into a single
ap_test_queue function that returns the AP status and the 64-bit
result. The exception table entry for PQAP(TAPQ) can be avoided
if the T bit for the APFT facility is set only if test_facility(15)
indicated that the facility is present.

Integrate ap_query_function into ap_query queue to avoid calling
PQAP(TAPQ) twice.

Reviewed-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: use msleep() instead of mdelay()

There is no need to busy loop and monopolize a cpu for up to ~2 seconds.
The code in question that calls mdelay() is preemptible anyway, so better
let the kernel schedule different processes than just looping and causing
unnecessary delays.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Fixed reset and interrupt handling of AP queues

In case of request timeouts an AP queue reset will be triggered to
recover and reinitialize the AP queue. The previous behavior was an
immediate reset execution regardless of current/pending requests.
Due to newly changed firmware behavior the reset may be delayed, based
on the priority of pending request. The device driver's waiting time
frame was limited, hence it did not received the reset response. As a
consequence interrupts would not be enabled afterwards.

The RAPQ (queue reset) and AQIC (interrupt control) commands will be
treated fully asynchronous now. The device driver will check the reset and
interrupt states periodically, thus it can handle the reinitialization
properly.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Fix invalid domain handling during ap module unload

Added domain checking to prevent reset failures caused by invalid
domains.
Corrected removal sequence of bus attributes and device.

Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: fixed ap poll timer behavior

The ap poll timer restart condition was wrong. Hence the poll timer
was not restarted reliable when setting a new time interval via the
poll_timeout sysfs attribute.
Added missing timer locking.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: remove test_facility(2) (== z/Architecture mode active) checks

Given that the kernel now always runs in 64 bit mode, it is
pointless to check if the z/Architecture mode is active.
Remove the checks.

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

s390: remove 31 bit support

Remove the 31 bit support in order to reduce maintenance cost and
effectively remove dead code. Since a couple of years there is no
distribution left that comes with a 31 bit kernel.

The 31 bit kernel also has been broken since more than a year before
anybody noticed. In addition I added a removal warning to the kernel
shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning
message") which let everybody know about the plan to remove 31 bit
code. We didn't get any response.

Given that the last 31 bit only machine was introduced in 1999 let's
remove the code.
Anybody with 31 bit user space code can still use the compat mode.

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

s390/zcrypt: fixed domain scanning problem (again)

Older machines with more then 16 domains need a special check before
PQAP instructions can be processed. With commit 5bc334bff9a6e189 this
check was reverted by accident. This patch re-establishes the additional
code needed for checking the extended domains for older machines.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Add support for new crypto express (CEX5S) adapter.

Extends the generic cryptographic device driver (zcrypt)
to support the Crypto Express 5S adapter.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Number of supported ap domains is not retrievable.

Upcoming versions of secure key management facilities (CCA and
EP11) require information about the maximum number of supported
ap domains in order to service TKE requests properly. With IBM
z13 the number of available domains (so far 16) has increased up
to 85. This number varies depending on machine types and models.
Therefore the new sysfs attribute 'ap_max_domain_id' provides
this limit of supported ap domains. Upcoming releases for CCA
and EP11 will use this new information. Without this problem fix
it is not possible to retrieve reliable information about the
maximum number of supported ap domains. Thus, customers are not
able to perform key management for CCA and EP11 coprocessor
adapters.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: kernel oops at insmod of the z90crypt device driver

Kernel oops caused by invalid parameter at TAPQ instruction:
On older systems where the QCI instruction is not available
all possible domains are probed via TAPQ instruction. The
range for the probe has been extended with the > 16 domain
support now leading to a possible specification exception
when this instruction is called for probing higher values
within the new range. This may happen during insmod and/or
ap bus reset only on machines without a QCI instruction (z10,
z196, z114), zEC12 and newer systems are not affected.
The fix modifies the domain checking function to limit the
allowed range if no QCI info is available.

Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

crypto: prefix module autoloading with "crypto-"

This prefixes all crypto module loading with "crypto-" so we never run
the risk of exposing module auto-loading to userspace via a crypto API,
as demonstrated by Mathias Krause:

https://lkml.org/lkml/2013/3/4/70

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

s390/zcrypt: Toleration of new crypto hardware

The zcrypt device driver will accept the new crypto adapter
in toleration mode. A new sysfs attribute 'raw_hwtype' will
expose the raw hardware type.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>

s390/zcrypt: support for extended number of ap domains

Extends the number of ap domains within the zcrypt device driver up to 256.
AP domains in the range 00..255 will be detected.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: improve device probing for zcrypt adapter cards

Improve device probing process for zcrypt adapters to
transmit service request during registration process.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ap_bus: Make modules parameters visible in sysfs

Change the visibility of the module parameters ap_domain_index and
ap_thread_flag for the owner and the members of the owners group in
sysfs.

Previously the parameters where invisible due to a value of zero
as permissions parameter in the module_param_named macro.

Signed-off-by: Michael Veigel <veigel@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

sched, treewide: Replace hardcoded nice values with MIN_NICE/MAX_NICE

Replace various -20/+19 hardcoded nice values with MIN_NICE/MAX_NICE.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/ff13819fd09b7a5dba5ab5ae797f2e7019bdfa17.1394532288.git.yangds.fnst@cn.fujitsu.com
Cc: devel@driverdev.osuosl.org
Cc: devicetree@vger.kernel.org
Cc: fcoe-devel@open-fcoe.org
Cc: linux390@de.ibm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-s390@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: nbd-general@lists.sourceforge.net
Cc: ocfs2-devel@oss.oracle.com
Cc: openipmi-developer@lists.sourceforge.net
Cc: qla2xxx-upstream@qlogic.com
Cc: linux-arch@vger.kernel.org
[ Consolidated the patches, twiddled the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

s390/zcrypt: add support for EP11 coprocessor cards

This feature extends the generic cryptographic device driver (zcrypt)
with a new capability to service EP11 requests for the Crypto Express4S
card in EP11 (Enterprise PKCS#11 mode) coprocessor mode.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ap_bus: use and-mask instead of a cast

Let's get rid of another sparse false positive:

drivers/s390/crypto/ap_bus.c:416:64: warning:
cast truncates bits from constant value (102030405060708 becomes 5060708)

So instead of using a cast let's use an and-mask.
That way sparse remains silent and one doesn't always have to check
if this is a valid warning/bug or just a false positive.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/zcrypt: Alias for new zcrypt device driver base module

The zcrypt device driver has been split into base/bus module, api-module,
card modules and message type modules. The base module has been renamed
from z90crypt to ap.
A module alias (with the well-known z90crypt identifier) will be introduced
that enable users to use their existing way to load the zcrypt device driver.

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/airq: simplify adapter interrupt code

There are three users of adapter interrupts: AP, QDIO and PCI. Each
registers a single adapter interrupt with independent ISCs. Define
a "struct airq" with the interrupt handler, a pointer and a mask for
the local summary indicator and the ISC for the adapter interrupt
source. Convert the indicator array with its fixed number of adapter
interrupt sources per ISE to an array of hlists. This removes the
limitation to 32 adapter interrupts per ISC and allows for arbitrary
memory locations for the local summary indicator.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ap_bus: Cocci spatch "ptr_ret.spatch"

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: ap bus rescan problem when toggle crypto adapters on/off

The bus rescan process was called simultaneously on
every device failure. This finally leads into race
conditions (double device add/remove actions).

This patch protects the rescan area by mutual exclusion
and improves ap_config_timer handling

Signed-off-by: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/irq: remove split irq fields from /proc/stat

Now that irq sum accounting for /proc/stat's "intr" line works again we
have the oddity that the sum field (first field) contains only the sum
of the second (external irqs) and third field (I/O interrupts).
The reason for that is that these two fields are already sums of all other
fields. So if we would sum up everything we would count every interrupt
twice.
This is broken since the split interrupt accounting was merged two years
ago: 052ff461c8427629aee887ccc27478fc7373237c "[S390] irq: have detailed
statistics for interrupt types".
To fix this remove the split interrupt fields from /proc/stat's "intr"
line again and only have them in /proc/interrupts.

This restores the old behaviour, seems to be the only sane fix and mimics
a behaviour from other architectures where /proc/interrupts also contains
more than /proc/stat's "intr" line does.

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

s390/ap_bus: add missing ifdef

Get rid of this compile warning for CONFIG_32BIT:

drivers/s390/crypto/ap_bus.c:168:12: warning: ‘ap_configuration_available’
defined but not used [-Wunused-function]

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

s390/zcryt: Handle AP configuration changes

Detect external AP bus configuration changes and request
an AP device rescan.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/zcrypt: Add support for CEX4 crypto card

New zcrypt module supports IBM CryptoExpress 4 cards.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ap: Add functiton facility information as AP device attribute.

Add the function facility information as new ap_device and sysfs
attribute. Also make the number of requests in device
queue and in device driver queue accessible in sysfs.

Reviewed-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ap: configuration information exploitation

Query AP configuration information. Improve performance of AP bus
scans by skipping AP device probing, if the AP deviec is not
configured.

Reviewed-by: Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com>
Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

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>

s390/ap: resend enable adapter interrupt request.

The adapter interrupt for an APQN must be re-enabled after a reset.
This patch sends the interrupt enablement request again, if the APQN
is busy or the reset is still in progress.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

s390/ap: Fix wrong or missing comments

Fix wrong or missing comments of ap inline assemblies.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390/ap: move receive callback to message struct

Move the receive callback from zdev_driver to ap_message structure to
get a more flexible asynchronous ap message handling.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Remove all #inclusions of asm/system.h

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>

Disintegrate asm/system.h for S390

Disintegrate asm/system.h for S390.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-s390@vger.kernel.org

[S390] Remove monolithic build option for zcrypt driver.

Remove the option to build a single module z90crypt that contains
ap bus, request router and card drivers.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] ap: Setup timer for sending messages after reset.

Setup timer for processing messages in request queue after a
successful AP bus device reset.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] ap: Setup processing for messages in request queue.

Setup timer for processing messages in request queue, if sending an AP
message returns with reason code AP_RESPONSE_RESET_IN_PROGRESS.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[S390] ap: toleration support for ap device type 10

Add toleration support for ap devices with device type 10.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] ap: skip device registration on type probe failure

The registration of an ap device will be skipped, if the device type
probing fails.
Add names of current crypto adapters to the Kconfig help.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: Introduce check for 4096 bit support.

Implemented an asm in the ap bus and made it accessible for the card
specific parts of the zcrypt driver. Thus when a cex3a is recognized
a check can be performed to dermine whether the card supports 4096 bit
RSA keys.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] ap bus: add support for irq statistics

Add support for AP Bus I/O interrupt statistics in /proc/interrupts.

Signed-off-by: Holger Dengler <hd@linux.vnet.ibm.com>
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: Fix check to look for facility bits 2 & 65

Fix the check for ap interupts to look for facility bits 2 and 65.
Make sure that we only register interrupts for aps, if the machine
has ap interrupt support.

This patch is relevant only for the 2.6.37 stable series.

Cc: stable@kernel.org
Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] cleanup facility list handling

Store the facility list once at system startup with stfl/stfle and
reuse the result for all facility tests.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

[S390] zcrypt: Do not simultaneously schedule hrtimer

Protect the hrtimer ap_poll_timer from being scheduled at the same
time from several processes.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: special command support for cex3 exploitation

Support for special command is implemented in the AP Bus in the NQAP
function __ap_send. This is extended for a further parameter special.
When set, the special bit, in GR0 will be set. Therefor the ap_message
struct is extended for a further bit. Thus calling functions of
__ap_send can use the special parameter in ap_message to give to
__ap_send. Affected is in the first place ap_queue_message, which is
called by the actual card driver. The second part of this support is
that the card driver for the CEX3C needs to set this special bit, when
an according CPRB is sent to the driver.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Ralph Wuerthner <ralph.wuerthner@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: Do not add/remove devices in s/r callbacks

Devices are no longer removed or added in the suspend and resume
callbacks. Instead they are marked unregistered in suspend. In the
resume callback the ap_scan_bus method is scheduled. The bus scan
function will remove the old device and add new ones. This way all
the device handling will be done in only one function. Additionaly
the case where the domain might change during suspend/resume is
caught. In that case the devices qid needs to re-calculated in
order of having it found by the scan method.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: Free ap_device if dev_set_name fails.

If dev_set_name fails during scanning the AP bus, the reserved memory
has to be freed.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: Use spin_lock_bh in suspend callback

Fix lock dependency warning.

inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
bash/1442 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&ap_dev->lock){+.?...}, at: [<000003e001280404>] __ap_poll_device+0x40/0x3e8 [ap]
{IN-SOFTIRQ-W} state was registered at:
[<000000000017f094>] __lock_acquire+0xb78/0x182c
[<000000000017fe8e>] lock_acquire+0x146/0x178
[<0000000000549cf2>] _spin_lock+0x5a/0x98
[<000003e001280404>] __ap_poll_device+0x40/0x3e8 [ap]
[<000003e001280afe>] ap_poll_all+0xaa/0x1a4 [ap]
[<000000000014fa82>] tasklet_action+0xfe/0x1f4
[<0000000000150a56>] __do_softirq+0x116/0x284
[<0000000000111058>] do_softirq+0xe4/0xe8
[<00000000001504ba>] irq_exit+0xba/0xd8
[<00000000003dd04a>] do_IRQ+0x176/0x1fc
[<000000000011823c>] io_return+0x0/0x8
[<0000004bfbfd2c0e>] 0x4bfbfd2c0e

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] proper use of device register

Don't use kfree directly after device registration started.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: fix scheduling of hrtimer ap_poll_timer

Every time a request is enqueued or there is some work outstanding
from the ap_tasklet, the ap_poll_timer is scheduled again.
Unfortunately it was permanently called. It looked as if it was
started in the past and thus imediately expired.
This has been changed. First it is checked if the hrtimer is already
expired. Then the expiring time is forwarded and the timer restarted.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] ap/zcrypt: Suspend/Resume ap bus and zcrypt

Add Suspend/Resume support to ap bus and zcrypt. All enhancements are
done in the ap bus. No changes in the crypto card specific part are
necessary.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

s390: remove s390_root_dev_*()

Replace s390_root_dev_register() with root_device_register() etc.

[Includes fix from Cornelia Huck]

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[S390] convert ap_bus printks to pr_xxx macros.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] ap: Minor code beautification.

Changed some symbol names for a better and clearer code.

Signed-off-by: Christian Maaser <cmaaser@de.ibm.com>
Signed-off-by: Felix Beck <beckf@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: Use of Thin Interrupts

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: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] bus_id -> dev_set_name() changes

Convert most s390 users setting bus_id to dev_set_name().
css and ccw busses are deferred since they need some special
treatment.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

hrtimer: convert s390 to the new hrtimer apis

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts s390 to these accessors.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

[S390] ap: Use high-resolution timer for polling

The ap poll mechanism is converted to use a high-resolution timer for
polling. This allows more specific polling. With this a new sysfs
attribute is introduced to specify the polling rate in nanoseconds.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

[S390] zcrypt: Comments and kernel-doc cleanup

Comments, which suggested to be kernel-doc but were not in the right
formatting, have been corrected. Additionally some minor cleanup in
the comments has been done.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

[S390] zcrypt: fix ap_device_list handling

In ap_device_probe() we can add the new ap device to the internal
device list only if the device probe function successfully returns.
Otherwise we might end up with an invalid device in the internal ap
device list.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: Do not start ap poll thread per default

Do not start ap poll thread per default to increase perfomance with
z/VM.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

Driver core: change add_uevent_var to use a struct

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[S390] zcrypt: fix ap_reset_domain()

Resetting of a all queues within a domain requires that a domain must
be selected first.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt: fix request timeout handling

Under very high load zcrypt requests may timeout while waiting on the
request queue. Modify zcrypt that timeouts are based on crypto adapter
responses. A timeout occurs only if a crypto adapter does not respond
within a given time frame to sumitted requests.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

uevent: use add_uevent_var() instead of open coding it

Make use of add_uevent_var() instead of (often incorrectly) open coding it.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Eric Rannaud <eric.rannaud@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[S390] zcrypt: Fix ap_poll_requests counter in lost requests error path.

In the unlikely event that an AP device lost requests, don't forget to
update the ap_poll_requests counter too. Same must happen in case an AP
device is removed while there are still outstanding requests.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

[S390] zcrypt: Fix possible dead lock in AP bus module.

If a AP device is unconfigured __ap_poll_all() will call
device_unregister() in software interrupt context which can cause
dead locks. To fix this the device will be only marked as unconfigured
and the device_unregister() call will be done later by either
ap_scan_bus() or ap_queue_message() in process context.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

[S390] zcrypt: fix possible dead lock in AP bus module

AP bus module uses bus_for_each_dev() in software interrupt context to
poll for completed requests which might cause dead locks. Solution: use
private AP device list for polling in software interrupt context.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] Avoid excessive inlining.

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

[S390] zcrypt: module unload fixes.

Add code to reset all queues for a domain and add missing tasklet_kill
call to ap bus module exit code.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] add reset call handler to the ap bus.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[PATCH] More work_struct induced breakage (s390)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[S390] Add MODALIAS= to the uevent for the ap bus.

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

[S390] Improve AP bus device removal.

Added a call to device_unregister() in ap_scan_bus() to actively
remove unavailable AP bus devices with every bus scan. Previously
devices were only removed in ap_queue_message() or __ap_poll_all().

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] ap bus poll thread priority.

The ap bus is supposed to have a low priority. We must use 19 instead
of -20, which is just the opposite.

Signed-off-by: Christian Borntraeger <cborntra@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt device registration/unregistration race.

Fix a race condition during AP device registration and unregistration.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

[S390] zcrypt adjunct processor bus.

Add a bus for the adjunct processor interface. Up to 64 devices can
be connect to the ap bus interface, each device with 16 domains. That
makes 1024 message queues. The interface is asynchronous, the answer
to a message sent to a queue needs to be received at some later point
in time. Unfortunately the interface does not provide interrupts when
a message reply is pending. So the ap bus needs to implement some
fancy polling, each active queue is polled once per 1/HZ second or
continuously if an idle cpus exsists and the poll thread is activ
(see poll_thread parameter).

The ap bus uses the sysfs path /sys/bus/ap and has two bus attributes,
ap_domain and config_time. The ap_domain selects one of the 16 domains
to be used for this system. This limits the maximum number of ap devices
to 64. The config_time attribute contains the number of seconds between
two ap bus scans to find new devices.

The ap bus uses the modalias entries of the form "ap:tN" to autoload
the ap driver for hardware type N. Currently known types are:
3 - PCICC, 4 - PCICA, 5 - PCIXCC, 6 - CEX2A and 7 - CEX2C.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>