For each PCI function we need to maintain arch specific data in
struct zpci_dev which also contains a pointer to struct pci_dev.

When a function is registered or deregistered (which is triggered by PCI
common code) we need to adjust that pointer which could interfere with
the machine check handler (triggered by FW) using zpci_dev->pdev.

Since multiple instances of the same pdev could exist at a time this can't
be solved with locking.

Fix that by ditching the pdev pointer and use a bus walk to reach
struct pci_dev (only one instance of a pdev can be registered at the bus
at a time).
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We receive special notifications from firmware when an error was detected
and a pci function became unusable. Set the error_state accordingly to give
device drivers a hint that they don't need to try error recovery.
Suggested-by: NAlexander Schmidt <alexschm@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Make sure that we use the pci_rescan_remove_lock when we remove
or add functions from/to the bus.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Receiving error events for a pci function that's currently not in use
will crash the kernel. For example the procedure for FW upgrades might
include:
* remove the function from Linux
* apply FW upgrade
* rescan for new functions

Receiving an event during the FW upgrade will result in a use after free
when printing the functions name. Just print "n/a" in such cases.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Hypervisors may deliver event 0x301 not only for standby
but also for reserved devices.
Just handle event 0x301 regardless of the device's state.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

KMSG_COMPONENT has to be defined instead of COMPONENT.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Processing pci hotplug events can fail when a pci function is in an
unexpected state. This can happen when we already processed the
change associated with the hotplug event (especially when receiving
hotplug events during early boot).
Just ignore the event in this case.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When using the CLP interface to enable or disable a pci device a
valid function handle needs to be delivered. So far our assumption
was that we always have an up-to-date version of the function handle
(since it doesn't change when the device is in use). This assumption
is incorrect if the pci device is enabled or disabled outside of our
control. When we are notified about such a change we already receive
the new function handle. Just use it.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If we receive a notification that a pci function became unavailable we clean
up by removing the pci device. This can confuse the driver since the function
is already unaccessible. Improve this situation by setting an appropriate
error_state.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

If we remove a pci bus after receiving a hotplug notification we need
to check if the bus is actually present (creation of the pci bus
during an earlier notification may have been failed).
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Initialization and scanning of the pci bus is omitted on older
machines without pci support or if pci=off was specified. Remember
the fact that we ran without pci support and prevent further bus
scans during resume from hibernate or after receiving hotplug
notifications.
Reported-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When the availability of a pci function has changed by means
outside of our control we receive an availability event.
Implement/improve the handling of these notifications.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Cleanup arch specific pci messages. Remove unhelpful messages and
replace others with entries in the debugfs.
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

List pci functions is used to query and iterate over pci functions.
This function currently has 2 users - initial device discovery and
rescan after a machine check. Instead of having a multipurpose
function pass a callback which gets called for each pci function.
Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add support for reading the PCI function measurement block counters
provided by the hypervisor. Add two s390 debug features, one for
critical errors and one for tracing and provide wrappers to log data.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add CHSC store-event-information support for PCI (notfication type 2)
and report error and availability events to the PCI architecture layer.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>