powerpc/mce: log the error for all unrecoverable errors

For all unrecoverable errors we are missing to log the
error, Since machine_check_log_err() is not getting called
for unrecoverable errors. ma

powerpc/mce: log the error for all unrecoverable errors

For all unrecoverable errors we are missing to log the
error, Since machine_check_log_err() is not getting called
for unrecoverable errors. machine_check_log_err() is called
from deferred handler, To run deferred handlers we have to do
irq work raise from the exception handler.

For recoverable errors exception vector code takes care of
running deferred handlers.

For unrecoverable errors raise irq work in save_mce_event(),
So that we log the error from MCE deferred handler.

Log without this change

MCE: CPU27: machine check (Severe) Real address Load/Store (foreign/control memory) [Not recovered]
MCE: CPU27: PID: 10580 Comm: inject-ra-err NIP: [0000000010000df4]
MCE: CPU27: Initiator CPU
MCE: CPU27: Unknown

Log with this change

MCE: CPU24: machine check (Severe) Real address Load/Store (foreign/control memory) [Not recovered]
MCE: CPU24: PID: 1589811 Comm: inject-ra-err NIP: [0000000010000e48]
MCE: CPU24: Initiator CPU
MCE: CPU24: Unknown
RTAS: event: 5, Type: Platform Error (224), Severity: 3

Signed-off-by: Ganesh Goudar <[email protected]>
Reviewed-by: Mahesh Salgaonkar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: use early_cpu_to_node() in mce_init()

cpu_to_node() is not yet available (setup_arch() is called before
setup_per_cpu_areas() by start_kernel()).

Signed-off-by: Nicholas Piggin <npiggi

powerpc/mce: use early_cpu_to_node() in mce_init()

cpu_to_node() is not yet available (setup_arch() is called before
setup_per_cpu_areas() by start_kernel()).

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc: Move C prototypes out of asm-prototypes.h

We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc:
Introduce asm-prototypes.h"). It's purpose was for prototypes of C
functions

powerpc: Move C prototypes out of asm-prototypes.h

We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc:
Introduce asm-prototypes.h"). It's purpose was for prototypes of C
functions that are only called from asm, in order to fix sparse
warnings about missing prototypes.

A few months later Nick added a different use case in
commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm")
for C prototypes for exported asm functions. This is basically the
inverse of our original usage.

Since then we've added various prototypes to asm-prototypes.h for both
reasons, meaning we now need to unstitch it all.

Dispatch prototypes of C functions into relevant headers and keep
only the prototypes for functions defined in assembly.

For the time being, leave prom_init() there because moving it
into asm/prom.h or asm/setup.h conflicts with
drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o
This will be fixed later by untaggling asm/pci.h and asm/prom.h
or by renaming the function in shadowrom.c

Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu

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powerpc/mce: Avoid using irq_work_queue() in realmode

In realmode mce handler we use irq_work_queue() to defer
the processing of mce events, irq_work_queue() can only
be called when translation is e

powerpc/mce: Avoid using irq_work_queue() in realmode

In realmode mce handler we use irq_work_queue() to defer
the processing of mce events, irq_work_queue() can only
be called when translation is enabled because it touches
memory outside RMA, hence we enable translation before
calling irq_work_queue and disable on return, though it
is not safe to do in realmode.

To avoid this, program the decrementer and call the event
processing functions from timer handler.

Signed-off-by: Ganesh Goudar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: Modify the real address error logging messages

To avoid ambiguity, modify the strings in real address error
logging messages to "foreign/control memory" from "foreign",
Since the error

powerpc/mce: Modify the real address error logging messages

To avoid ambiguity, modify the strings in real address error
logging messages to "foreign/control memory" from "foreign",
Since the error discriptions in P9 user manual and P10 user
manual are different for same type of errors.

P9 User Manual for MCE:
DSISR:59 Host real address to foreign space during translation.
DSISR:60 Host real address to foreign space on a load or store
access.

P10 User Manual for MCE:
DSISR:59 D-side tablewalk used a host real address in the
control memory address range.
DSISR:60 D-side operand access to control memory address space.

Signed-off-by: Ganesh Goudar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU

Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig mi

powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU

Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig minus KVM,
350kB on pseries_defconfig minus KVM, 40kB on a tiny config.

Signed-off-by: Nicholas Piggin <[email protected]>
[mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG.
Fix radix_enabled() use in setup_initial_memory_limit(). Add some
stubs to reduce number of ifdefs.]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: Fix access error in mce handler

We queue an irq work for deferred processing of mce event in realmode
mce handler, where translation is disabled. Queuing of the work may
result in acces

powerpc/mce: Fix access error in mce handler

We queue an irq work for deferred processing of mce event in realmode
mce handler, where translation is disabled. Queuing of the work may
result in accessing memory outside RMO region, such access needs the
translation to be enabled for an LPAR running with hash mmu else the
kernel crashes.

After enabling translation in mce_handle_error() we used to leave it
enabled to avoid crashing here, but now with the commit
74c3354bc1d89 ("powerpc/pseries/mce: restore msr before returning from
handler") we are restoring the MSR to disable translation.

Hence to fix this enable the translation before queuing the work.

Without this change following trace is seen on injecting SLB multihit in
an LPAR running with hash mmu.

Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
CPU: 5 PID: 1883 Comm: insmod Tainted: G OE 5.14.0-mce+ #137
NIP: c000000000735d60 LR: c000000000318640 CTR: 0000000000000000
REGS: c00000001ebff9a0 TRAP: 0300 Tainted: G OE (5.14.0-mce+)
MSR: 8000000000001003 <SF,ME,RI,LE> CR: 28008228 XER: 00000001
CFAR: c00000000031863c DAR: c00000027fa8fe08 DSISR: 40000000 IRQMASK: 0
...
NIP llist_add_batch+0x0/0x40
LR __irq_work_queue_local+0x70/0xc0
Call Trace:
0xc00000001ebffc0c (unreliable)
irq_work_queue+0x40/0x70
machine_check_queue_event+0xbc/0xd0
machine_check_early_common+0x16c/0x1f4

Fixes: 74c3354bc1d89 ("powerpc/pseries/mce: restore msr before returning from handler")
Signed-off-by: Ganesh Goudar <[email protected]>
[mpe: Fix comment formatting, trim oops in change log for readability]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s: avoid reloading (H)SRR registers if they are still valid

When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime,

powerpc/64s: avoid reloading (H)SRR registers if they are still valid

When an interrupt is taken, the SRR registers are set to return to where
it left off. Unless they are modified in the meantime, or the return
address or MSR are modified, there is no need to reload these registers
when returning from interrupt.

Introduce per-CPU flags that track the validity of SRR and HSRR
registers. These are cleared when returning from interrupt, when
using the registers for something else (e.g., OPAL calls), when
adjusting the return address or MSR of a context, and when context
switching (which changes the return address and MSR).

This improves the performance of interrupt returns.

Signed-off-by: Nicholas Piggin <[email protected]>
[mpe: Fold in fixup patch from Nick]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc: Add missing linux/{of.h,irqdomain.h} include directives

A bunch of PPC files are missing the inclusion of linux/of.h and
linux/irqdomain.h, relying on transitive inclusion from another
file

powerpc: Add missing linux/{of.h,irqdomain.h} include directives

A bunch of PPC files are missing the inclusion of linux/of.h and
linux/irqdomain.h, relying on transitive inclusion from another
file.

As we are about to break this dependency, make sure these dependencies
are explicit.

Signed-off-by: Marc Zyngier <[email protected]>

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powerpc/mce: save ignore_event flag unconditionally for UE

When we hit an UE while using machine check safe copy routines,
ignore_event flag is set and the event is ignored by mce handler,
And the f

powerpc/mce: save ignore_event flag unconditionally for UE

When we hit an UE while using machine check safe copy routines,
ignore_event flag is set and the event is ignored by mce handler,
And the flag is also saved for defered handling and printing of
mce event information, But as of now saving of this flag is done
on checking if the effective address is provided or physical address
is calculated, which is not right.

Save ignore_event flag regardless of whether the effective address is
provided or physical address is calculated.

Without this change following log is seen, when the event is to be
ignored.

[ 512.971365] MCE: CPU1: machine check (Severe) UE Load/Store [Recovered]
[ 512.971509] MCE: CPU1: NIP: [c0000000000b67c0] memcpy+0x40/0x90
[ 512.971655] MCE: CPU1: Initiator CPU
[ 512.971739] MCE: CPU1: Unknown
[ 512.972209] MCE: CPU1: machine check (Severe) UE Load/Store [Recovered]
[ 512.972334] MCE: CPU1: NIP: [c0000000000b6808] memcpy+0x88/0x90
[ 512.972456] MCE: CPU1: Initiator CPU
[ 512.972534] MCE: CPU1: Unknown

Signed-off-by: Ganesh Goudar <[email protected]>
Reviewed-by: Santosh Sivaraj <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: Make symbol 'mce_ue_event_work' static

The sparse tool complains as follows:

arch/powerpc/kernel/mce.c:43:1: warning:
symbol 'mce_ue_event_work' was not declared. Should it be static?

powerpc/mce: Make symbol 'mce_ue_event_work' static

The sparse tool complains as follows:

arch/powerpc/kernel/mce.c:43:1: warning:
symbol 'mce_ue_event_work' was not declared. Should it be static?

This symbol is not used outside of mce.c, so this commit marks it
static.

Signed-off-by: Li Huafei <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc: move NMI entry/exit code into wrapper

This moves the common NMI entry and exit code into the interrupt handler
wrappers.

This changes the behaviour of soft-NMI (watchdog) and HMI interrupt

powerpc: move NMI entry/exit code into wrapper

This moves the common NMI entry and exit code into the interrupt handler
wrappers.

This changes the behaviour of soft-NMI (watchdog) and HMI interrupts, and
also MCE interrupts on 64e, by adding missing parts of the NMI entry to
them.

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc: convert interrupt handlers to use wrappers

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/2021013013

powerpc: convert interrupt handlers to use wrappers

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: Remove per cpu variables from MCE handlers

Access to per-cpu variables requires translation to be enabled on
pseries machine running in hash mmu mode, Since part of MCE handler
runs in

powerpc/mce: Remove per cpu variables from MCE handlers

Access to per-cpu variables requires translation to be enabled on
pseries machine running in hash mmu mode, Since part of MCE handler
runs in realmode and part of MCE handling code is shared between ppc
architectures pseries and powernv, it becomes difficult to manage
these variables differently on different architectures, So have
these variables in paca instead of having them as per-cpu variables
to avoid complications.

Signed-off-by: Ganesh Goudar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: Include prototypes

It fixes these W=1 compile errors :

../arch/powerpc/kernel/mce.c:591:14: error: no previous prototype for ‘machine_check_early’ [-Werror=missing-prototypes]
591 |

powerpc/mce: Include prototypes

It fixes these W=1 compile errors :

../arch/powerpc/kernel/mce.c:591:14: error: no previous prototype for ‘machine_check_early’ [-Werror=missing-prototypes]
591 | long notrace machine_check_early(struct pt_regs *regs)
| ^~~~~~~~~~~~~~~~~~~
../arch/powerpc/kernel/mce.c:725:6: error: no previous prototype for ‘hmi_exception_realmode’ [-Werror=missing-prototypes]
725 | long hmi_exception_realmode(struct pt_regs *regs)
| ^~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Cédric Le Goater <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s: Remove "Host" from MCE logging

"Host" caused machine check is printed when the kernel sees a MCE
hit in this kernel or userspace, and "Guest" if it hit one of its
guests. This is confus

powerpc/64s: Remove "Host" from MCE logging

"Host" caused machine check is printed when the kernel sees a MCE
hit in this kernel or userspace, and "Guest" if it hit one of its
guests. This is confusing when a guest kernel handles a hypervisor-
delivered MCE, it also prints "Host".

Just remove "Host". "Guest" is adequate to make the distinction.

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s/powernv: Allow KVM to handle guest machine check details

KVM has strategies to perform machine check recovery. If a MCE hits
in a guest, have the low level handler just decode and save t

powerpc/64s/powernv: Allow KVM to handle guest machine check details

KVM has strategies to perform machine check recovery. If a MCE hits
in a guest, have the low level handler just decode and save the MCE
but not try to recover anything, so KVM can deal with it.

The host does not own SLBs and does not need to report the SLB state
in case of a multi-hit for example, or know about the virtual memory
map of the guest.

UE and memory poisoning of guest pages in the host is one thing that
is possibly not completely robust at the moment, but this too needs
to go via KVM (possibly via the guest and back out to host via hcall)
rather than being handled at a low level in the host handler.

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash

Use of nmi_enter/exit in real mode handler causes the kernel to panic
and reboot on injecting SLB mutihit on pseries machine running in

powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash

Use of nmi_enter/exit in real mode handler causes the kernel to panic
and reboot on injecting SLB mutihit on pseries machine running in hash
MMU mode, because these calls try to accesses memory outside RMO
region in real mode handler where translation is disabled.

Add check to not to use these calls on pseries machine running in hash
MMU mode.

Fixes: 116ac378bb3f ("powerpc/64s: machine check interrupt update NMI accounting")
Cc: [email protected] # v5.8+
Signed-off-by: Ganesh Goudar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s: Move HMI IRQ stat from percpu variable to paca.

With the proposed change in percpu bootmem allocator to use page
mapping [1], the percpu first chunk memory area can come from vmalloc
ra

powerpc/64s: Move HMI IRQ stat from percpu variable to paca.

With the proposed change in percpu bootmem allocator to use page
mapping [1], the percpu first chunk memory area can come from vmalloc
ranges. This makes the HMI (Hypervisor Maintenance Interrupt) handler
crash the kernel whenever percpu variable is accessed in real mode.
This patch fixes this issue by moving the HMI IRQ stat inside paca for
safe access in realmode.

[1] https://lore.kernel.org/linuxppc-dev/[email protected]/

Suggested-by: Aneesh Kumar K.V <[email protected]>
Signed-off-by: Mahesh Salgaonkar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/159290806973.3642154.5244613424529764050.stgit@jupiter

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powerpc/powernv: Machine check handler for POWER10

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/20200702233

powerpc/powernv: Machine check handler for POWER10

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/mce: Add MCE notification chain

Introduce notification chain which lets us know about uncorrected memory
errors(UE). This would help prospective users in pmem or nvdimm subsystem
to track ba

powerpc/mce: Add MCE notification chain

Introduce notification chain which lets us know about uncorrected memory
errors(UE). This would help prospective users in pmem or nvdimm subsystem
to track bad blocks for better handling of persistent memory allocations.

Signed-off-by: Santosh Sivaraj <[email protected]>
Signed-off-by: Ganesh Goudar <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s: machine check do not trace real-mode handler

Rather than notrace annotations throughout a significant part of the
machine check code across kernel/ pseries/ and powernv/ which can
easil

powerpc/64s: machine check do not trace real-mode handler

Rather than notrace annotations throughout a significant part of the
machine check code across kernel/ pseries/ and powernv/ which can
easily be broken and is infrequently tested, use paca->ftrace_enabled
to blanket-disable tracing of the real-mode non-maskable handler.

Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Reviewed-by: Christophe Leroy <[email protected]>
Acked-by: Naveen N. Rao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s: machine check interrupt update NMI accounting

machine_check_early() is taken as an NMI, so nmi_enter() is used
there. machine_check_exception() is no longer taken as an NMI (it's
invoke

powerpc/64s: machine check interrupt update NMI accounting

machine_check_early() is taken as an NMI, so nmi_enter() is used
there. machine_check_exception() is no longer taken as an NMI (it's
invoked via irq_work in the case a machine check hits in kernel mode),
so remove the nmi_enter() from that case.

In NMI context, hash faults don't try to refill the hash table, which
can lead to crashes accessing non-pinned kernel pages. System reset
still has this potential problem.

Signed-off-by: Nicholas Piggin <[email protected]>
[mpe: Drop change in show_regs() which breaks Book3E]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/pseries: Handle UE event for memcpy_mcsafe

memcpy_mcsafe has been implemented for power machines which is used
by pmem infrastructure, so that an UE encountered during memcpy from
pmem devic

powerpc/pseries: Handle UE event for memcpy_mcsafe

memcpy_mcsafe has been implemented for power machines which is used
by pmem infrastructure, so that an UE encountered during memcpy from
pmem devices would not result in panic instead a right error code
is returned. The implementation expects machine check handler to ignore
the event and set nip to continue the execution from fixup code.

Appropriate changes are already made to powernv machine check handler,
make similar changes to pseries machine check handler to ignore the
the event and set nip to continue execution at the fixup entry if we
hit UE at an instruction with a fixup entry.

while we are at it, have a common function which searches the exception
table entry and updates nip with fixup address, and any future common
changes can be made in this function that are valid for both architectures.

powernv changes are made by
commit 895e3dceeb97 ("powerpc/mce: Handle UE event for memcpy_mcsafe")

Reviewed-by: Mahesh Salgaonkar <[email protected]>
Reviewed-by: Santosh S <[email protected]>
Signed-off-by: Ganesh Goudar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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powerpc/64s/pseries: machine check convert to use common event code

The common machine_check_event data structures and queues are mostly
platform independent, with powernv decoding SRR1/DSISR/etc.,

powerpc/64s/pseries: machine check convert to use common event code

The common machine_check_event data structures and queues are mostly
platform independent, with powernv decoding SRR1/DSISR/etc., into
machine_check_event objects.

This patch converts pseries to use this infrastructure by decoding
fwnmi/rtas data into machine_check_event objects.

This allows queueing to be used by a subsequent change to delay the
virtual mode handling of machine checks that occur in kernel space
where it is unsafe to switch immediately to virtual mode, similarly
to powernv.

Signed-off-by: Nicholas Piggin <[email protected]>
[mpe: Fix implicit fallthrough warnings in mce_handle_error()]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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