powerpc/powernv: Remove machine check handling in OPAL.

Now that we are ready to handle machine check directly in linux, do not
register with firmware to handle machine check exception.

Signed-off-

powerpc/powernv: Remove machine check handling in OPAL.

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: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/book3s: Queue up and process delayed MCE events.

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

powerpc/book3s: Queue up and process delayed MCE events.

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: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/book3s: Decode and save machine check event.

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
i

powerpc/book3s: Decode and save machine check event.

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: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Code update interface

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

This patch includes:
- Belo

powerpc/powernv: Code update interface

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: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Create opal sysfs directory

Create /sys/firmware/opal directory. We wil use this
interface to fetch opal error logs, firmware update, etc.

Signed-off-by: Vasant Hegde <hegdevasant@

powerpc/powernv: Create opal sysfs directory

Create /sys/firmware/opal directory. We wil use this
interface to fetch opal error logs, firmware update, etc.

Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Fix some PCI sparse errors and one LE bug

pnv_pci_setup_bml_iommu was missing a byteswap of a device
tree property.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by:

powerpc/powernv: Fix some PCI sparse errors and one LE bug

pnv_pci_setup_bml_iommu was missing a byteswap of a device
tree property.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Don't register exception handlers in little endian mode

The powernv exception handlers are not ready to take exceptions
in little endian mode, so disable them.

Signed-off-by: Benja

powerpc/powernv: Don't register exception handlers in little endian mode

The powernv exception handlers are not ready to take exceptions
in little endian mode, so disable them.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Fix endian issues in OPAL console and udbg backend

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: Little endian fixes for platforms/powernv/opal.c

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: add explicit OF includes

When removing prom.h include by of.h, several OF headers will no longer
be implicitly included. Add explicit includes of of_*.h as needed.

Signed-off-by: Rob Herri

powerpc: add explicit OF includes

When removing prom.h include by of.h, several OF headers will no longer
be implicitly included. Add explicit includes of of_*.h as needed.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: linuxppc-dev@lists.ozlabs.org

show more ...

powerpc/powernv: Don't crash if there are no OPAL consoles

Some machines might provide the console via a different mechanism
such as direct access to a UART from Linux, in which case OPAL
might not

powerpc/powernv: Don't crash if there are no OPAL consoles

Some machines might provide the console via a different mechanism
such as direct access to a UART from Linux, in which case OPAL
might not expose any console. In that case, the code would cause
a NULL dereference.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc: Fix a number of sparse warnings

Address some of the trivial sparse warnings in arch/powerpc.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@ke

powerpc: Fix a number of sparse warnings

Address some of the trivial sparse warnings in arch/powerpc.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powernv/opal: Notifier for OPAL events

This patch implements a notifier to receive a notification on OPAL
event mask changes. The notifier is only called as a result of an OPAL
interrupt, which will

powernv/opal: Notifier for OPAL events

This patch implements a notifier to receive a notification on OPAL
event mask changes. The notifier is only called as a result of an OPAL
interrupt, which will happen upon reception of FSP messages or PCI errors.
Any event mask change detected as a result of opal_poll_events() will not
result in a notifier call.

[benh: changelog]
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Detect OPAL v3 API version

Future firmwares will support that new version

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/powernv: Improve kexec reliability

We add a machine_shutdown hook that frees the OPAL interrupts
(so they get masked at the source and don't fire while kexec'ing)
and which triggers an IODA

powerpc/powernv: Improve kexec reliability

We add a machine_shutdown hook that frees the OPAL interrupts
(so they get masked at the source and don't fire while kexec'ing)
and which triggers an IODA reset on all the PCIe host bridges
which will have the effect of blocking all DMAs and subsequent
PCIs interrupts.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Properly drop characters if console is closed

If the firmware returns an error such as "closed" (or hardware
error), we should drop characters.

Currently we only do that when a fir

powerpc/powernv: Properly drop characters if console is closed

If the firmware returns an error such as "closed" (or hardware
error), we should drop characters.

Currently we only do that when a firmware compatible with OPAL v2
APIs is detected, in the code that calls opal_console_write_buffer_space(),
which didn't exist with OPAL v1 (or didn't work).

However, when enabling early debug consoles, the flag indicating
that v2 is supported isn't set yet, causing us, in case of errors
or closed console, to spin forever.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Defer OPAL exception handler registration

Currently, the OPAL exception vectors are registered before the feature
fixups are processed. This means that the now-firmware-owned vector

powerpc/powernv: Defer OPAL exception handler registration

Currently, the OPAL exception vectors are registered before the feature
fixups are processed. This means that the now-firmware-owned vectors
will likely be overwritten by the kernel.

This change moves the exception registration code to an early initcall,
rather than at machine_init time.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Machine check and other system interrupts

OPAL can handle various interrupt for us such as Machine Checks (it
performs all sorts of recovery tasks and passes back control to us with

powerpc/powernv: Machine check and other system interrupts

OPAL can handle various interrupt for us such as Machine Checks (it
performs all sorts of recovery tasks and passes back control to us with
informations about the error), Hardware Management Interrupts and Softpatch
interrupts.

This wires up the mechanisms and prints out specific informations returned
by HAL when a machine check occurs.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Register and handle OPAL interrupts

We do the minimum which is to "pass" interrupts to HAL, which
makes the console smoother and will allow us to implement
interrupt based completio

powerpc/powernv: Register and handle OPAL interrupts

We do the minimum which is to "pass" interrupts to HAL, which
makes the console smoother and will allow us to implement
interrupt based completion and console.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Support for OPAL console

This adds a udbg and an hvc console backend for supporting a console
using the OPAL console interfaces.

On OPAL v1 we have hvc0 mapped to whatever console

powerpc/powernv: Support for OPAL console

This adds a udbg and an hvc console backend for supporting a console
using the OPAL console interfaces.

On OPAL v1 we have hvc0 mapped to whatever console the system was
configured for (network or hvsi serial port) via the service
processor.

On OPAL v2 we have hvcN mapped to the Nth console provided by OPAL
which generally corresponds to:

hvc0 : network console (raw protocol)
hvc1 : serial port S1 (hvsi)
hvc2 : serial port S2 (hvsi)

Note: At this point, early debug console only works with OPAL v1
and shouldn't be enabled in a normal kernel.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/powernv: Basic support for OPAL

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 firmwar

powerpc/powernv: Basic support for OPAL

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: Benjamin Herrenschmidt <benh@kernel.crashing.org>

show more ...

powerpc/64: irq replay remove decrementer overflow check

[ Upstream commit 59d512e4374b2d8a6ad341475dc94c4a4bdec7d3 ]

This is way to catch some cases of decrementer overflow, when t

powerpc/64: irq replay remove decrementer overflow check

[ Upstream commit 59d512e4374b2d8a6ad341475dc94c4a4bdec7d3 ]

This is way to catch some cases of decrementer overflow, when the
decrementer has underflowed an odd number of times, while MSR[EE] was
disabled.

With a typical small decrementer, a timer that fires when MSR[EE] is
disabled will be "lost" if MSR[EE] remains disabled for between 4.3 and
8.6 seconds after the timer expires. In any case, the decrementer
interrupt would be taken at 8.6 seconds and the timer would be found at
that point.

So this check is for catching extreme latency events, and it prevents
those latencies from being a further few seconds long. It's not obvious
this is a good tradeoff. This is already a watchdog magnitude event and
that situation is not improved a significantly with this check. For
large decrementers, it's useless.

Therefore remove this check, which avoids a mftb when enabling hard
disabled interrupts (e.g., when enabling after coming from hardware
interrupt handlers). Perhaps more importantly, it also removes the
clunky MSR[EE] vs PACA_IRQ_HARD_DIS incoherency in soft-interrupt replay
which simplifies the code.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201107014336.2337337-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

powerpc/powernv: add NULL check after kzalloc

Fixes coccicheck warning:

./arch/powerpc/platforms/powernv/opal.c:813:1-5:
alloc with no test, possible model on line 814

powerpc/powernv: add NULL check after kzalloc

Fixes coccicheck warning:

./arch/powerpc/platforms/powernv/opal.c:813:1-5:
alloc with no test, possible model on line 814

Add NULL check after kzalloc.

Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200509020838.121660-1-chenzhou10@huawei.com

show more ...

powerpc/powernv: Use common code for the symbol_map export

Long before we had a generic way for firmware to export memory ranges of
interest we added a special case for the skiboot symbo

powerpc/powernv: Use common code for the symbol_map export

Long before we had a generic way for firmware to export memory ranges of
interest we added a special case for the skiboot symbol map. The code is
pretty much identical to the generic export so re-use the code.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101062611.32610-2-oohall@gmail.com

show more ...

powerpc/powernv: Rework exports to support subnodes

Originally we only had a handful of exported memory ranges, but we'd to
export the per-core trace buffers. This results in a lot of fi

powerpc/powernv: Rework exports to support subnodes

Originally we only had a handful of exported memory ranges, but we'd to
export the per-core trace buffers. This results in a lot of files in the
exports directory which is a but unfortunate. We can clean things up a bit
by turning subnodes into subdirectories of the exports directory.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101062611.32610-1-oohall@gmail.com

show more ...