This change adds a char device to access the "PRD" (processor runtime
diagnostics) channel to OPAL firmware.

Includes contributions from Vaidyanathan Srinivasan, Neelesh Gupta &
Vishal Kulkarni.
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: NJeremy Kerr <jk@ozlabs.org>
Acked-by: NStewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Whenever an interrupt is received for opal the linux kernel gets a
bitfield indicating certain events that have occurred and need handling
by the various device drivers. Currently this is handled using a
notifier interface where we call every device driver that has
registered to receive opal events.

This approach has several drawbacks. For example each driver has to do
its own checking to see if the event is relevant as well as event
masking. There is also no easy method of recording the number of times
we receive particular events.

This patch solves these issues by exposing opal events via the
standard interrupt APIs by adding a new interrupt chip and
domain. Drivers can then register for the appropriate events using
standard kernel calls such as irq_of_parse_and_map().
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This is a cleanup patch; doesn't change any functionality. Moves
all cpuidle related code from setup.c to a new file.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
[mpe: Fix the SMP=n build by including asm/smp.h in idle.c]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The patch removes unused file eeh-ioda.c and updates makefile
accordingly. Besides, the definition of "struct pnv_eeh_ops" and
the instances are all removed. Until now, the chip layer of EEH
implementation for PowerNV platform is removed completely.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Register a notifier for a OPAL message indicating that the machine
should prepare itself for a graceful power off.

OPAL will tell us if the power off is a reboot or shutdown, but for now
we perform the same orderly_poweroff action.
Signed-off-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

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>

Knowing how long we spend in firmware calls is an important part of
minimising OS jitter.

This patch adds tracepoints to each OPAL call. If tracepoints are
enabled we branch out to a common routine that calls an entry and exit
tracepoint.

This allows us to write tools that monitor the frequency and duration
of OPAL calls, eg:

name                  count  total(ms)  min(ms)  max(ms)  avg(ms)  period(ms)
OPAL_HANDLE_INTERRUPT     5      0.199    0.037    0.042    0.040   12547.545
OPAL_POLL_EVENTS        204      2.590    0.012    0.036    0.013    2264.899
OPAL_PCI_MSI_EOI       2830      3.066    0.001    0.005    0.001      81.166

We use jump labels if configured, which means we only add a single
nop instruction to every OPAL call when the tracepoints are disabled.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In commit 27f44888 "Add OPAL takeover from PowerVM" we added support
for "takeover" on OPAL v1 machines.

This was a mode of operation where we would boot under pHyp, and query
for the presence of OPAL. If detected we would then do a special
sequence to take over the machine, and the kernel would end up running
in hypervisor mode.

OPAL v1 was never a supported product, and was never shipped outside
IBM. As far as we know no one is still using it.

Newer versions of OPAL do not use the takeover mechanism. Although the
query for OPAL should be harmless on machines with newer OPAL, we have
seen a machine where it causes a crash in Open Firmware.

The code in early_init_devtree() to copy boot_command_line into cmd_line
was added in commit 817c21ad "Get kernel command line accross OPAL
takeover", and AFAIK is only used by takeover, so should also be
removed.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Build throws following errors when CONFIG_SMP=n
arch/powerpc/platforms/powernv/subcore.c: In function ‘cpu_update_split_mode’:
arch/powerpc/platforms/powernv/subcore.c:274:15: error: ‘setup_max_cpus’ undeclared (first use in this function)
arch/powerpc/platforms/powernv/subcore.c:285:5: error: lvalue required as left operand of assignment

'setup_max_cpus' variable is relevant only on SMP, so there is no point
working around it for UP. Furthermore, subcore itself is relevant only
on SMP and hence the better solution is to exclude subcore.o and
subcore-asm.o for UP builds.
Signed-off-by: NShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>
Reviewed-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Upcoming POWER8 chips support a concept called split core. This is where the
core can be split into subcores that although not full cores, are able to
appear as full cores to a guest.

The splitting & unsplitting procedure is mildly complicated, and explained at
length in the comments within the patch.

One notable detail is that when splitting or unsplitting we need to pull
offline cpus out of their offline state to do work as part of the procedure.

The interface for changing the split mode is via a sysfs file, eg:

 $ echo 2 > /sys/devices/system/cpu/subcores_per_core

Currently supported values are '1', '2' and '4'. And indicate respectively that
the core should be unsplit, split in half, and split in quarters. These modes
correspond to threads_per_subcore of 8, 4 and 2.

We do not allow changing the split mode while KVM VMs are active. This is to
prevent the value changing while userspace is configuring the VM, and also to
prevent the mode being changed in such a way that existing guests are unable to
be run.

CPU hotplug fixes by Srivatsa.  max_cpus fixes by Mahesh.  cpuset fixes by
benh.  Fix for irq race by paulus.  The rest by mikey and mpe.
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
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>

This patch enables fetching of various platform sensor data through
OPAL and expects a sensor handle from the driver to pass to OPAL.
Signed-off-by: NNeelesh Gupta <neelegup@linux.vnet.ibm.com>
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 patch adds support for notifying the clients of their request
completion. Clients request for the token before making OPAL call
and then wait for the response.

This patch uses messaging infrastructure to pull the data to linux
by registering itself for the message type OPAL_MSG_ASYNC_COMP.
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>

Get the memory errors reported by opal and plumb it into memory poison
infrastructure. This patch uses new messaging channel infrastructure to
pull the fsp memory errors to linux.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Code update interface for powernv platform. This provides
sysfs interface to pass new image, validate, update and
commit images.

This patch includes:
  - Below OPAL APIs for code update
    - opal_validate_flash()
    - opal_manage_flash()
    - opal_update_flash()

  - Create below sysfs files under /sys/firmware/opal
    - image		: Interface to pass new FW image
    - validate_flash	: Validate candidate image
    - manage_flash	: Commit/Reject operations
    - update_flash	: Flash new candidate image

Updating Image:
  "update_flash" is an interface to indicate flash new FW.
It just passes image SG list to FW. Actual flashing is done
during system reboot time.

Note:
  - SG entry format:
    I have kept version number to keep this list similar to what
    PAPR is defined.
Signed-off-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

OPAL v3 provides interfaces to access the chips XSCOM, expose
this via the existing scom infrastructure.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Add the plumbing to implement arch_get_random_long/int(). It didn't seem
worth adding an extra ppc_md hook for int, so we reuse the one for long.

Add an implementation for powernv based on the hwrng found in power7+
systems. We whiten the output of the hwrng, and the result passes all
the dieharder tests.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This uses the hooks provided by CONFIG_PPC_INDIRECT_PIO to
implement a set of hooks for IO port access to use the LPC
bus via OPAL calls for the first 64K of IO space
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch adds EEH backends for PowerNV platform. It's notable that
part of those EEH backends call to the I/O chip dependent backends.

[Removed pointless change to eeh_pseries.c -- BenH]
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

For EEH on PowerNV platform, the overall architecture is different
from that on pSeries platform. In order to support multiple I/O chips
in future, we split EEH to 3 layers for PowerNV platform: EEH core,
platform layer, I/O layer. It would give EEH implementation on PowerNV
platform much more flexibility in future.

The patch adds the EEH backend for P7IOC.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This adds support for p7IOC (and possibly other IODA v1 IO Hubs)
using OPAL v2 interfaces.

We completely take over resource assignment and assign them using an
algorithm that hands out device BARs in a way that makes them fit in
individual segments of the M32 window of the bridge, which enables us
to assign individual PEs to devices and functions.

The current implementation gives out a PE per functions on PCIe, and a
PE for the entire bridge for PCIe to PCI-X bridges.

This can be adjusted / fine tuned later.

We also setup DMA resources (32-bit only for now) and MSIs (both 32-bit
and 64-bit MSI are supported).

The DMA allocation tries to divide the available 256M segments of the
32-bit DMA address space "fairly" among PEs. This is done using a
"weight" heuristic which assigns less value to things like OHCI USB
controllers than, for example SCSI RAID controllers. This algorithm
will probably want some fine tuning for specific devices or device
types.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This adds support for PCI-X and PCIe on the p5ioc2 IO hub using
OPAL. This includes allocating & setting up TCE tables and config
space access routines.

This also supports fallbacks via RTAS when OPAL is absent, using
legacy TCE format pre-allocated via the device-tree (BML style)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Implements OPAL RTC and NVRAM support and wire all that up to
the powernv platform.

We use RTAS for RTC as a fallback if available. Using RTAS for nvram
is not supported yet, pending some rework/cleanup and generalization
of the pSeries & CHRP code. We also use RTAS fallbacks for power off
and reboot
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Add definition of OPAL interfaces along with  the wrappers to call
into OPAL runtime and the early device-tree parsing hook to locate
the OPAL runtime firmware.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On machines supporting the OPAL firmware version 1, the system
is initially booted under pHyp. We then use a special hypercall
to verify if OPAL is available and if it is, we then trigger
a "takeover" which disables pHyp and loads the OPAL runtime
firmware, giving control to the kernel in hypervisor mode.

This patch add the necessary code to detect that the OPAL takeover
capability is present when running under PowerVM (aka pHyp) and
perform said takeover to get hypervisor control of the processor.

To perform the takeover, we must first use RTAS (within Open
Firmware runtime environment) to start all processors & threads,
in order to give control to OPAL on all of them. We then call
the takeover hypercall on everybody, OPAL will re-enter the kernel
main entry point passing it a flat device-tree.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This adds a skeletton for the new Power "Non Virtualized"
platform which will be used by machines supporting running
without an hypervisor, for example in order to run KVM.

These machines will be using a new firmware called OPAL
for which the support will be provided by later patches.

The PowerNV platform is intended to be also usable under
the BML environment used internally for early CPU bringup
which is why the code also supports using RTAS instead of
OPAL in various places.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>