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: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NJason J. Herne <jjherne@linux.ibm.com>
Signed-off-by: NAlexander Gordeev <agordeev@linux.ibm.com>

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: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NJürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

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: NHarald Freudenberger <freude@linux.ibm.com>
Tested-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NJürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

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: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NJürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

This patch adds CEX8 exploitation support for the AP bus code,
the zcrypt device driver zoo and the vfio device driver.
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NJürgen Christ <jchrist@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NJakob Naucke <naucke@linux.ibm.com>
Reviewed-by: NJuergen Christ <jchrist@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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

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: NTony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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

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

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

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: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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

The device struct itself already contains a pointer to its driver.
Use this consistently, instead of duplicating it.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

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: NMathieu 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: NMark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: NPali 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: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: NVinod 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: NJohan 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: NMaximilian 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: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: NFinn Thain <fthain@linux-m68k.org>
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NIngo Tuchscherer <ingo.tuchscherer@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NIngo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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

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: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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

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: NIngo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

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: NMarc Hartmayer <mhartmay@linux.ibm.com>
Fixes: 4f2fcccd ("s390/ap: add card/queue deconfig state")
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

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

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

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

The spinlock ap_poll_timer_lock is initialized statically. It is
unnecessary to initialize by spin_lock_init().
Signed-off-by: NQinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NKees Cook <keescook@chromium.org>

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

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

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: NHarald Freudenberger <freude@linux.ibm.com>
Suggested-by: NTony Krowiak <akrowiak@linux.ibm.com>
Suggested-by: NHalil Pasic <pasic@linux.ibm.com>
Reviewed-by: NTony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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: NJoe Perches <joe@perches.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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

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: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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

This patch adds CEX7 exploitation support for the AP bus code,
the zcrypt device driver zoo and the vfio device driver.
Signed-off-by: NHarald Freudenberger <freude@linux.ibm.com>
Reviewed-by: NIngo Franzki <ifranzki@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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: f1b0a434 ("s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h.")
Fixes: 050349b5 ("s390/zcrypt: externalize AP config info query")
Signed-off-by: NDenis Efremov <efremov@linux.com>
Reviewed-by: NHarald Freudenberger <freude@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

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: NCorey Minyard <minyard@acm.org>
Acked-by: NDavid Kershner <david.kershner@unisys.com>
Acked-by: NMark Brown <broonie@kernel.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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

Add an extra parameter for airq handlers to recognize
floating vs. directed interrupts.
Signed-off-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>