Provide an unregister interface for the opal message notifiers
to be called when not needed like during driver unload/remove.
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Reviewed-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Fixes the condition check of incoming message type which can
otherwise shoot beyond the message notifiers head array.
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Reviewed-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Reviewed-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

If OPAL requests it, call it back via opal_poll_events() at a
regular interval. Some versions of OPAL on some machines require
this to operate some internal timeouts properly.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This commit gets opal-api.h to mostly match the version in Skiboot as of
commit ea7d806ab0ba.

The exceptions are things which are not (currently) used in Linux.

Most of this is just whitespace and a few things moving around. I think
the diff is readable.

Also OpalMessageType became opal_msg_type, requiring a change in the
Linux code.

Finally Skiboot and Linux disagree on CAPI vs CXL, because CAPI means
something else in Linux. To handle that we just point the Linux wrapper,
which is named "cxl" to the OPAL token OPAL_PCI_SET_PHB_CAPI_MODE.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NStewart Smith <stewart@linux.vnet.ibm.com>

Correct use of REGISTER/UNREGISTER is to check if the token exists
before calling. If we don't we get a "OPAL: Called with bad token 101 !"
error, which is harmless but may be alarming to some.
Signed-off-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Acked-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

On PowerNV platform, the OPAL interrupts are exported by firmware
through device-node property (/ibm,opal::opal-interrupts). Under
some extreme circumstances (e.g. simulator), we don't have this
property found from the device tree. For that case, we shouldn't
allocate the interrupt map. Otherwise, slab complains allocating
zero sized memory chunk.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The patch put the OPAL interrupt setup logic in opal_init() into
seperate function opal_irq_init() for easier code maintaining. The
patch doesn't introduce logic changes except:

   * Rename variable names.
   * Release virtual IRQ upon error from request_irq().
   * Don't cache the virtual IRQ to opal_irqs[] upon error from
     request_irq().
Suggested-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

In commit c8742f85 "powerpc/powernv: Expose OPAL firmware symbol
map" I added pr_fmt() to opal.c. This left some existing pr_xxx()s with
duplicate "opal" prefixes, eg:

    opal: opal: Found 0 interrupts reserved for OPAL

Fix them all up. Also make the "Not not found" message a bit more
verbose.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

When CONFIG_PRINTK=n, log_buf_addr_get() returns NULL and log_buf_len_get()
return 0. Check for these return values and skip registering the dump buffer.
Signed-off-by: NPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Newer versions of OPAL will provide this, so let's expose it to user
space so tools like perf can use it to properly decode samples in
firmware space.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The patch exposes the available i2c busses on the PowerNV platform
to the kernel and implements the bus driver to support i2c and
smbus commands.
The driver uses the platform device infrastructure to probe the busses
on the platform and registers them with the i2c driver framework.
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> (I2C part, excluding the bindings)
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Cleanup OpalMCE_* definitions/declarations and other related code which
is not used anymore.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: NBenjamin Herrrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch implements the OPAL rtc driver that binds with the rtc
driver subsystem. The driver uses the platform device infrastructure
to probe the rtc device and register it to rtc class framework. The
'wakeup' is supported depending upon the property 'has-tpo' present
in the OF node. It provides a way to load the generic rtc driver in
in the absence of an OPAL driver.

The patch also moves the existing OPAL rtc get/set time interfaces to the
new driver and exposes the necessary OPAL calls using EXPORT_SYMBOL_GPL.

Test results:
-------------
Host:
[root@tul169p1 ~]# ls -l /sys/class/rtc/
total 0
lrwxrwxrwx 1 root root 0 Oct 14 03:07 rtc0 -> ../../devices/opal-rtc/rtc/rtc0
[root@tul169p1 ~]# cat /sys/devices/opal-rtc/rtc/rtc0/time
08:10:07
[root@tul169p1 ~]# echo `date '+%s' -d '+ 2 minutes'` > /sys/class/rtc/rtc0/wakealarm
[root@tul169p1 ~]# cat /sys/class/rtc/rtc0/wakealarm
1413274345
[root@tul169p1 ~]#

FSP:
$ smgr mfgState
standby
$ rtim timeofday

System time is valid: 2014/10/14 08:12:04.225115

$ smgr mfgState
ipling
$

CC: devicetree@vger.kernel.org
CC: tglx@linutronix.de
CC: rtc-linux@googlegroups.com
CC: a.zummo@towertech.it
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Recent OPAL firmare adds a couple of functions to send and receive IPMI
messages:

  https://github.com/open-power/skiboot/commit/b2a374da

This change updates the token list and wrappers to suit, and adds the
platform devices for any IPMI interfaces.
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Recently we moved HMI handling into Linux kernel instead of taking
HMI directly in OPAL. This new change is dependent on new OPAL call
for HMI recovery which was introduced in newer firmware. While this new
change works fine with latest OPAL firmware, we broke the HMI handling
if we run newer kernel on old OPAL firmware that results in system hang.

This patch fixes this issue by falling back to old HMI behavior on older
OPAL firmware.

This patch introduces a check for opal token OPAL_HANDLE_HMI to see
if we are running on newer firmware or old firmware. On newer firmware
this check would return OPAL_TOKEN_PRESENT, otherwise we are running on
old firmware and fallback to old HMI behavior.

Old firmware: POWER8 System Firmware Release as of today <= SV810_087
Action: Let OPAL handle HMIs

Newer firmware: in development/yet to be released.
Action: Let Linux host handle HMIs.

This patch depends on opal check token patch posted at ppc-devel
https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-August/120224.htmlSigned-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
[mpe: Minor comment and printk rewording]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Add printk levels to powernv platform code, and convert to
pr_err() etc while here.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This patch fix spelling typo in printk.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

PowerNV platform is capable of capturing host memory region when system
crashes (because of host/firmware). We have new OPAL API to register/
unregister memory region to be captured when system crashes.

This patch adds support for new API. Also during boot time we register
kernel log buffer and unregister before doing kexec.
Signed-off-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When we hit the HMI in Linux, invoke opal call to handle/recover from HMI
errors in real mode and then in virtual mode during check_irq_replay()
invoke opal_poll_events()/opal_do_notifier() to retrieve HMI event from
OPAL and act accordingly.

Now that we are ready to handle HMI interrupt directly in linux, remove
the HMI interrupt registration with firmware.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements
basic infrastructure to handle HMI in Linux host. The design is to invoke
opal handle hmi in real mode for recovery and set irq_pending when we hit HMI.
During check_irq_replay pull opal hmi event and print hmi info on console.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

A lot of the code in platforms/powernv is using non-machine initcalls.
That means if a kernel built with powernv support runs on another
platform, for example pseries, the initcalls will still run.

That is usually OK, because the initcalls will check for something in
the device tree or elsewhere before doing anything, so on other
platforms they will usually just return.

But it's fishy for powernv code to be running on other platforms, so
switch them all to be machine initcalls. If we want any of them to run
on other platforms in future they should move to sysdev.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When running as a powernv "host" system on P8, we need to switch
the endianness of interrupt handlers. This does it via the appropriate
call to the OPAL firmware which may result in just switching HID0:HILE
but depending on the processor version might need to do a few more
things. This call must be done early before any other processor has
been brought out of firmware.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndy Whitcroft <apw@canonical.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Make of_get_flat_dt_prop arguments compatible with libfdt fdt_getprop
call in preparation to convert FDT code to use libfdt. Make the return
value const and the property length ptr type an int.
Signed-off-by: NRob Herring <robh@kernel.org>
Tested-by: NMichal Simek <michal.simek@xilinx.com>
Tested-by: NGrant Likely <grant.likely@linaro.org>
Tested-by: NStephen Chivers <schivers@csc.com>

We have two copies of code that creates an OPAL sg list. Consolidate
these into a common set of helpers and fix the endian issues.

The flash interface embedded a version number in the num_entries
field, whereas the dump interface did did not. Since versioning
wasn't added to the flash interface and it is impossible to add
this in a backwards compatible way, just remove it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The bitmap in opal_poll_events and opal_handle_interrupt is
big endian, so we need to byteswap it on little endian builds.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This call will not be understood by OPAL, and cause it to add an error
to it's log. Among other things, this is useful for testing the
behaviour of the log as it fills up.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL provides an in-memory circular buffer containing a message log
populated with various runtime messages produced by the firmware.

Provide a sysfs interface /sys/firmware/opal/msglog for userspace to
view the messages.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we wrongly allocate mc_recoverable_range buffer (to hold
recoverable ranges) based on size of the property "mcheck-recoverable-ranges".
This results in allocating less memory to hold available recoverable range
entries from /proc/device-tree/ibm,opal/mcheck-recoverable-ranges.

This patch fixes this issue by allocating mc_recoverable_range buffer based
on number of entries of recoverable ranges instead of device property size.
Without this change we end up allocating less memory and run into memory
corruption issue.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL defines opal_msg as a big endian struct so we have to
byte swap it on little endian builds.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

opal_notifier_register() is missing a pending "unregister" variant
and should be exposed to modules.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch enables reading and updating of system parameters through
OPAL call.
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This enables support for userspace to fetch and initiate FSP and
Platform dumps from the service processor (via firmware) through sysfs.

Based on original patch from Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

Flow:
  - We register for OPAL notification events.
  - OPAL sends new dump available notification.
  - We make information on dump available via sysfs
  - Userspace requests dump contents
  - We retrieve the dump via OPAL interface
  - User copies the dump data
  - userspace sends ack for dump
  - We send ACK to OPAL.

sysfs files:
  - We add the /sys/firmware/opal/dump directory
  - echoing 1 (well, anything, but in future we may support
    different dump types) to /sys/firmware/opal/dump/initiate_dump
    will initiate a dump.
  - Each dump that we've been notified of gets a directory
    in /sys/firmware/opal/dump/ with a name of the dump type and ID (in hex,
    as this is what's used elsewhere to identify the dump).
  - Each dump has files: id, type, dump and acknowledge
    dump is binary and is the dump itself.
    echoing 'ack' to acknowledge (currently any string will do) will
    acknowledge the dump and it will soon after disappear from sysfs.

OPAL APIs:
  - opal_dump_init()
  - opal_dump_info()
  - opal_dump_read()
  - opal_dump_ack()
  - opal_dump_resend_notification()

Currently we are only ever notified for one dump at a time (until
the user explicitly acks the current dump, then we get a notification
of the next dump), but this kernel code should "just work" when OPAL
starts notifying us of all the dumps present.
Signed-off-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Based on a patch by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>

This patch adds support to read error logs from OPAL and export
them to userspace through a sysfs interface.

We export each log entry as a directory in /sys/firmware/opal/elog/

Currently, OPAL will buffer up to 128 error log records, we don't
need to have any knowledge of this limit on the Linux side as that
is actually largely transparent to us.

Each error log entry has the following files: id, type, acknowledge, raw.
Currently we just export the raw binary error log in the 'raw' attribute.
In a future patch, we may parse more of the error log to make it a bit
easier for userspace (e.g. to be able to display a brief summary in
petitboot without having to have a full parser).

If we have >128 logs from OPAL, we'll only be notified of 128 until
userspace starts acknowledging them. This limitation may be lifted in
the future and with this patch, that should "just work" from the linux side.

A userspace daemon should:
- wait for error log entries using normal mechanisms (we announce creation)
- read error log entry
- save error log entry safely to disk
- acknowledge the error log entry
- rinse, repeat.

On the Linux side, we read the error log when we're notified of it. This
possibly isn't ideal as it would be better to only read them on-demand.
However, this doesn't really work with current OPAL interface, so we
read the error log immediately when notified at the moment.

I've tested this pretty extensively and am rather confident that the
linux side of things works rather well. There is currently an issue with
the service processor side of things for >128 error logs though.
Signed-off-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Detect and recover from machine check when inside opal on a special
scom load instructions. On specific SCOM read via MMIO we may get a machine
check exception with SRR0 pointing inside opal. To recover from MC
in this scenario, get a recovery instruction address and return to it from
MC.

OPAL will export the machine check recoverable ranges through
device tree node mcheck-recoverable-ranges under ibm,opal:

# hexdump /proc/device-tree/ibm,opal/mcheck-recoverable-ranges
0000000 0000 0000 3000 2804 0000 000c 0000 0000
0000010 3000 2814 0000 0000 3000 27f0 0000 000c
0000020 0000 0000 3000 2814 xxxx xxxx xxxx xxxx
0000030 llll llll yyyy yyyy yyyy yyyy
...
...
#

where:
	xxxx xxxx xxxx xxxx = Starting instruction address
	llll llll           = Length of the address range.
	yyyy yyyy yyyy yyyy = recovery address

Each recoverable address range entry is (start address, len,
recovery address), 2 cells each for start and recovery address, 1 cell for
len, totalling 5 cells per entry. During kernel boot time, build up the
recovery table with the list of recovery ranges from device-tree node which
will be used during machine check exception to recover from MMIO SCOM UE.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Its possible that OPAL may be writing to host memory during
kexec (like dump retrieve scenario). In this situation we might
end up corrupting host memory.

This patch makes OPAL sync call to make sure OPAL stops
writing to host memory before kexec'ing.
Signed-off-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Opal now has a new messaging infrastructure to push the messages to
linux in a generic format for different type of messages using only one
event bit. The format of the opal message is as below:

struct opal_msg {
        uint32_t msg_type;
	uint32_t reserved;
	uint64_t params[8];
};

This patch allows clients to subscribe for notification for specific
message type. It is upto the subscriber to decipher the messages who showed
interested in receiving specific message type.

The interface to subscribe for notification is:

	int opal_message_notifier_register(enum OpalMessageType msg_type,
                                        struct notifier_block *nb)

The notifier will fetch the opal message when available and notify the
subscriber with message type and the opal message. It is subscribers
responsibility to copy the message data before returning from notifier
callback.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Add basic error handling in machine check exception handler.

- If MSR_RI isn't set, we can not recover.
- Check if disposition set to OpalMCE_DISPOSITION_RECOVERED.
- Check if address at fault is inside kernel address space, if not then send
  SIGBUS to process if we hit exception when in userspace.
- If address at fault is not provided then and if we get a synchronous machine
  check while in userspace then kill the task.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now that we are ready to handle machine check directly in linux, do not
register with firmware to handle machine check exception.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When machine check real mode handler can not continue into host kernel
in V mode, it returns from the interrupt and we loose MCE event which
never gets logged. In such a situation queue up the MCE event so that
we can log it later when we get back into host kernel with r1 pointing to
kernel stack e.g. during syscall exit.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Now that we handle machine check in linux, the MCE decoding should also
take place in linux host. This info is crucial to log before we go down
in case we can not handle the machine check errors. This patch decodes
and populates a machine check event which contain high level meaning full
MCE information.

We do this in real mode C code with ME bit on. The MCE information is still
available on emergency stack (in pt_regs structure format). Even if we take
another exception at this point the MCE early handler will allocate a new
stack frame on top of current one. So when we return back here we still have
our MCE information safe on current stack.

We use per cpu buffer to save high level MCE information. Each per cpu buffer
is an array of machine check event structure indexed by per cpu counter
mce_nest_count. The mce_nest_count is incremented every time we enter
machine check early handler in real mode to get the current free slot
(index = mce_nest_count - 1). The mce_nest_count is decremented once the
MCE info is consumed by virtual mode machine exception handler.

This patch provides save_mce_event(), get_mce_event() and release_mce_event()
generic routines that can be used by machine check handlers to populate and
retrieve the event. The routine release_mce_event() will free the event slot so
that it can be reused. Caller can invoke get_mce_event() with a release flag
either to release the event slot immediately OR keep it so that it can be
fetched again. The event slot can be also released anytime by invoking
release_mce_event().

This patch also updates kvm code to invoke get_mce_event to retrieve generic
mce event rather than paca->opal_mce_evt.

The KVM code always calls get_mce_event() with release flags set to false so
that event is available for linus host machine

If machine check occurs while we are in guest, KVM tries to handle the error.
If KVM is able to handle MC error successfully, it enters the guest and
delivers the machine check to guest. If KVM is not able to handle MC error, it
exists the guest and passes the control to linux host machine check handler
which then logs MC event and decides how to handle it in linux host. In failure
case, KVM needs to make sure that the MC event is available for linux host to
consume. Hence KVM always calls get_mce_event() with release flags set to false
and later it invokes release_mce_event() only if it succeeds to handle error.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>