Refactor the estatus queue's pool notification routine from
NOTIFY_NMI's handlers. This will allow another notification
method to use the estatus queue without duplicating this code.

Add rcu_read_lock()/rcu_read_unlock() around the list
list_for_each_entry_rcu() walker. These aren't strictly necessary as
the whole nmi_enter/nmi_exit() window is a spooky RCU read-side
critical section.

in_nmi_queue_one_entry() is separate from the rcu-list walker for a
later caller that doesn't need to walk a list.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NPunit Agrawal <punit.agrawal@arm.com>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
[ rjw: Drop unnecessary err variable in two places ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

ghes_read_estatus() sets a flag in struct ghes if the buffer of
CPER records needs to be cleared once the records have been
processed. This flag value is a problem if a struct ghes can be
processed concurrently, as happens at probe time if an NMI arrives
for the same error source. The NMI clears the flag, meaning the
interrupted handler may never do the ghes_estatus_clear() work.

The GHES_TO_CLEAR flags is only set at the same time as
buffer_paddr, which is now owned by the caller and passed to
ghes_clear_estatus(). Use this value as the flag.

A non-zero buf_paddr returned by ghes_read_estatus() means
ghes_clear_estatus() should clear this address. ghes_read_estatus()
already checks for a read of error_status_address being zero,
so CPER records cannot be written here.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

ghes_notify_nmi() checks ghes->flags for GHES_TO_CLEAR before going
on to __process_error(). This is pointless as ghes_read_estatus()
will always set this flag if it returns success, which was checked
earlier in the loop. Remove it.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When CPER records are found the address of the records is stashed
in the struct ghes. Once the records have been processed, this
address is overwritten with zero so that it won't be processed
again without being re-populated by firmware.

This goes wrong if a struct ghes can be processed concurrently,
as can happen at probe time when an NMI occurs. If the NMI arrives
on another CPU, the probing CPU may call ghes_clear_estatus() on the
records before the handler had finished with them.
Even on the same CPU, once the interrupted handler is resumed, it
will call ghes_clear_estatus() on the NMIs records, this memory may
have already been re-used by firmware.

Avoid this stashing by letting the caller hold the address. A
later patch will do away with the use of ghes->flags in the
read/clear code too.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Adding new NMI-like notifications duplicates the calls that grow
and shrink the estatus pool. This is all pretty pointless, as the
size is capped to 64K. Allocate this for each ghes and drop
the code that grows and shrinks the pool.
Suggested-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

ghes.c has a memory pool it uses for the estatus cache and the estatus
queue. The cache is initialised when registering the platform driver.
For the queue, an NMI-like notification has to grow/shrink the pool
as it is registered and unregistered.

This is all pretty noisy when adding new NMI-like notifications, it
would be better to replace this with a static pool size based on the
number of users.

As a precursor, move the call that creates the pool from ghes_init(),
into hest.c. Later this will take the number of ghes entries and
consolidate the queue allocations.
Remove ghes_estatus_pool_exit() as hest.c doesn't have anywhere to put
this.

The pool is now initialised as part of ACPI's subsys_initcall():
(acpi_init(), acpi_scan_init(), acpi_pci_root_init(), acpi_hest_init())
Before this patch it happened later as a GHES specific device_initcall().
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ghes code is careful to parse and round firmware's advertised
memory requirements for CPER records, up to a maximum of 64K.
However when ghes_estatus_pool_expand() does its work, it splits
the requested size into PAGE_SIZE granules.

This means if firmware generates 5K of CPER records, and correctly
describes this in the table, __process_error() will silently fail as it
is unable to allocate more than PAGE_SIZE.

Switch the estatus pool to vmalloc() memory. On x86 vmalloc() memory
may fault and be fixed up by vmalloc_fault(). To prevent this call
vmalloc_sync_all() before an NMI handler could discover the memory.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Subsequent patches will split up ghes_read_estatus(), at which
point passing around the 'silent' flag gets annoying. This is to
suppress prink() messages, which prior to commit 42a0bb3f
("printk/nmi: generic solution for safe printk in NMI"), were
unsafe in NMI context.

This is no longer necessary, remove the flag. printk() messages
are batched in a per-cpu buffer and printed via irq-work, or a call
back from panic().
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

oops_begin() exists to group printk() messages with the oops message
printed by die(). To reach this caller we know that platform firmware
took this error first, then notified the OS via NMI with a 'panic'
severity.

Don't wait for another CPU to release the die-lock before panic()ing,
our only goal is to print this fatal error and panic().

This code is always called in_nmi(), and since commit 42a0bb3f
("printk/nmi: generic solution for safe printk in NMI"), it has been
safe to call printk() from this context. Messages are batched in a
per-cpu buffer and printed via irq-work, or a call back from panic().

Link: https://patchwork.kernel.org/patch/10313555/Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In __ghes_panic() clear the block status in the APEI generic
error status block for that generic hardware error source before
calling panic() to prevent a second panic() in the crash kernel
for exactly the same fatal error.

Otherwise ghes_probe(), running in the crash kernel, would see
an unhandled error in the APEI generic error status block and
panic again, thereby precluding any crash dump.
Signed-off-by: NLenny Szubowicz <lszubowi@redhat.com>
Signed-off-by: NDavid Arcari <darcari@redhat.com>
Tested-by: NTyler Baicar <baicar.tyler@gmail.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The use of the @ghes argument was removed in a previous commit, but
function signature was not updated to reflect this.
Signed-off-by: NAlexandru Gagniuc <mr.nuke.me@gmail.com>
Acked-by: N"Rafael J. Wysocki" <rafael@kernel.org>
Cc: linux-acpi@vger.kernel.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180430213358.8319-1-mr.nuke.me@gmail.comSigned-off-by: NBorislav Petkov <bp@suse.de>

Tony reported seeing

  "Internal error: Can't find EDAC structure"

when injecting correctable errors due to the fact that ghes_edac would
still load even if the whitelist won't hit. Drop the pr_err() in
ghes_edac_report_mem_error() for now due to the hacky way how ghes_edac
depends on ghes.c.

While at it, make ghes_edac_register() return an error if it doesn't hit
in the whitelist as it is the only sensible thing to do in that
situation.

Furthermore, move the call to it to happen last in ghes_probe() so that
GHES initializing properly does not depend on ghes_edac init at all
as latter is only reporting errors and not required for GHES's proper
functioning.
Reviewed-by: NToshi Kani <toshi.kani@hpe.com>
Tested-by: NSughosh Ganu <sughosh.ganu@arm.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20180420182015.zao3olss4tvvlxki@agluck-desk

Today 4 architectures set ARCH_SUPPORTS_MEMORY_FAILURE (arm64, parisc,
powerpc, and x86), while 4 other architectures set __ARCH_SI_TRAPNO
(alpha, metag, sparc, and tile).  These two sets of architectures do
not interesect so remove the trapno paramater to remove confusion.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Variables len and node_len are redundant and can be removed. Cleans
up clang warning: node_len = GHES_ESTATUS_NODE_LEN(len);
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently the GHES code only calls into the AER driver for
recoverable type errors. This is incorrect because errors of
other severities do not get logged by the AER driver and do not
get exposed to user space via the AER trace event. So, call
into the AER driver for PCIe errors regardless of the severity
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Move PCIe AER error handling code into a separate function.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that nothing is using the ghes_ioremap_area pages, rip them out.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All applicable <stable@vger.kernel.org>

Replace ghes_io{re,un}map_pfn_{nmi,irq}()s use of ioremap_page_range()
with __set_fixmap() as ioremap_page_range() may sleep to allocate a new
level of page-table, even if its passed an existing final-address to
use in the mapping.

The GHES driver can only be enabled for architectures that select
HAVE_ACPI_APEI: Add fixmap entries to both x86 and arm64.

clear_fixmap() does the TLB invalidation in __set_fixmap() for arm64
and __set_pte_vaddr() for x86. In each case its the same as the
respective arch_apei_flush_tlb_one().
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Tested-by: NToshi Kani <toshi.kani@hpe.com>
[ For the arm64 bits: ]
Acked-by: NWill Deacon <will.deacon@arm.com>
[ For the x86 bits: ]
Acked-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All applicable <stable@vger.kernel.org>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tyler Baicar <tbaicar@codeaurora.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: "Jonathan (Zhixiong) Zhang" <zjzhang@codeaurora.org>
Cc: Shiju Jose <shiju.jose@huawei.com>
Cc: linux-acpi@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>

For the SEA notification, the two functions ghes_sea_add() and
ghes_sea_remove() are only called when CONFIG_ACPI_APEI_SEA
is defined. If not, it will return errors in the ghes_probe()
and not continue. If the probe is failed, the ghes_sea_remove()
also has no chance to be called. Hence, remove the unnecessary
handling when CONFIG_ACPI_APEI_SEA is not defined.

For the NMI notification, it has the same issue as SEA notification,
so also remove the unused dead-code for it.
Signed-off-by: NDongjiu Geng <gengdongjiu@huawei.com>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Match up with what 7edda088 ("acpi: apei: handle SEA notification
type for ARMv8") did for ghes_ioremap_pfn_nmi().
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently we acknowledge errors before clearing the error status.
This could cause a new error to be populated by firmware in-between
the error acknowledgment and the error status clearing which would
cause the second error's status to be cleared without being handled.
So, clear the error status before acknowledging the errors.

Also, make sure to acknowledge the error if the error status read
fails.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

According to the ACPI specification, firmware is not required to provide
the Hardware Error Source Table (HEST). When HEST is not present, the
following superfluous message is printed to the kernel boot log -

[    3.460067] GHES: HEST is not enabled!

Extend hest_disable variable to track whether the firmware provides this
table and if it is not present skip any log output. The existing
behaviour is preserved in all other cases.
Suggested-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

X-Gene platforms describe multiple GHES error sources with the same
hardware error notification type (external interrupt) and interrupt
number.

Change the GHES interrupt request to support sharing the same IRQ.

This change includs contributions from Tuan Phan <tphan@apm.com>.
Signed-off-by: NLoc Ho <lho@apm.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Check for pending errors when probing GHES entries. It is possible
that a fatal error is already pending at this point, so we should
handle it as soon as the driver is probed. This also avoids a
potential issue if there was an interrupt that was already
cleared for an error since the GHES driver wasn't present.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Currently external aborts are unsupported by the guest abort
handling. Add handling for SEAs so that the host kernel reports
SEAs which occur in the guest kernel.

When an SEA occurs in the guest kernel, the guest exits and is
routed to kvm_handle_guest_abort(). Prior to this patch, a print
message of an unsupported FSC would be printed and nothing else
would happen. With this patch, the code gets routed to the APEI
handling of SEAs in the host kernel to report the SEA information.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NChristoffer Dall <cdall@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Currently there are trace events for the various RAS
errors with the exception of ARM processor type errors.
Add a new trace event for such errors so that the user
will know when they occur. These trace events are
consistent with the ARM processor error section type
defined in UEFI 2.6 spec section N.2.4.4.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Reviewed-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The UEFI spec includes non-standard section type support in the
Common Platform Error Record. This is defined in section N.2.3 of
UEFI version 2.5.

Currently if the CPER section's type (UUID) does not match any
section type that the kernel knows how to parse, a trace event is
not generated.

Generate a trace event which contains the raw error data for
non-standard section type error records.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Tested-by: NShiju Jose <shiju.jose@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Even if an error status block's severity is fatal, the kernel does not
honor the severity level and panic.

With the firmware first model, the platform could inform the OS about a
fatal hardware error through the non-NMI GHES notification type. The OS
should panic when a hardware error record is received with this
severity.

Call panic() after CPER data in error status block is printed if
severity is fatal, before each error section is handled.
Signed-off-by: NJonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

ARM APEI extension proposal added SEA (Synchronous External Abort)
notification type for ARMv8.
Add a new GHES error source handling function for SEA. If an error
source's notification type is SEA, then this function can be registered
into the SEA exception handler. That way GHES will parse and report
SEA exceptions when they occur.
An SEA can interrupt code that had interrupts masked and is treated as
an NMI. To aid this the page of address space for mapping APEI buffers
while in_nmi() is always reserved, and ghes_ioremap_pfn_nmi() is
changed to use the helper methods to find the prot_t to map with in
the same way as ghes_ioremap_pfn_irq().
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Reviewed-by: NJames Morse <james.morse@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The ACPI 6.1 spec adds a new revision of the generic error data
entry structure. Add support to handle the new structure as well
as properly verify and iterate through the generic data entries.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

A RAS (Reliability, Availability, Serviceability) controller
may be a separate processor running in parallel with OS
execution, and may generate error records for consumption by
the OS. If the RAS controller produces multiple error records,
then they may be overwritten before the OS has consumed them.

The Generic Hardware Error Source (GHES) v2 structure
introduces the capability for the OS to acknowledge the
consumption of the error record generated by the RAS
controller. A RAS controller supporting GHESv2 shall wait for
the acknowledgment before writing a new error record, thus
eliminating the race condition.

Add support for parsing of GHESv2 sub-tables as well.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzhang@codeaurora.org>
Reviewed-by: NJames Morse <james.morse@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

There are new types and helpers that are supposed to be used in new code.

As a preparation to get rid of legacy types and API functions do
the conversion here.

Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

System Controller Interrupts are received by ACPI's error device, which
in turn notifies the GHES code. The same is true of APEI's GSIV and
GPIO notification types. Add support for GSIV and GPIO sharing the SCI
register/unregister/notifier code. Rename the list and notifier to show
this is no longer just SCI, but anything from the Hardware Error Device.
Signed-off-by: NShiju Jose <shiju.jose@huawei.com>
[ Rewrite commit log. ]
Signed-off-by: NJames Morse <james.morse@arm.com>
[ Some small cleanups ontop. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NJames Morse <james.morse@arm.com>
Link: http://lkml.kernel.org/r/86258A5CC0A3704780874CF6004BA8A62E695201@FRAEML521-MBX.china.huawei.com
Cc: "Guohanjun (Hanjun Guo)" <guohanjun@huawei.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: "Zhengqiang (turing)" <zhengqiang10@huawei.com>
Cc: "fu.wei@linaro.org" <fu.wei@linaro.org>
Cc: "xuwei (O)" <xuwei5@hisilicon.com>
Cc: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Cc: Geliang Tang <geliangtang@gmail.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Punit Agrawal <punit.agrawal@arm.com>
Cc: linux-acpi@vger.kernel.org
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use setup_deferrable_timer() instead of init_timer_deferrable() to
simplify the code.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Link: http://lkml.kernel.org/r/3afa5498142ef68256023257dad37b9f8352e65e.1489060803.git.geliangtang@gmail.comSigned-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

When removing a GHES device notified by SCI, list_del_rcu() is used,
ghes_remove() should call synchronize_rcu() before it goes on to call
kfree(ghes), otherwise concurrent RCU readers may still hold this list
entry after it has been freed.
Signed-off-by: NJames Morse <james.morse@arm.com>
Reviewed-by: N"Huang, Ying" <ying.huang@intel.com>
Fixes: 81e88fdc (ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.

Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

When removing and adding cpu 0 on a system with GHES NMI the following stack
trace is seen when re-adding the cpu:

WARNING: CPU: 0 PID: 0 at arch/x86/kernel/apic/apic.c:1349 setup_local_APIC+
Modules linked in: nfsv3 rpcsec_gss_krb5 nfsv4 nfs fscache coretemp intel_ra
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc6+ #2
Call Trace:
 dump_stack+0x63/0x8e
 __warn+0xd1/0xf0
 warn_slowpath_null+0x1d/0x20
 setup_local_APIC+0x275/0x370
 apic_ap_setup+0xe/0x20
 start_secondary+0x48/0x180
 set_init_arg+0x55/0x55
 early_idt_handler_array+0x120/0x120
 x86_64_start_reservations+0x2a/0x2c
 x86_64_start_kernel+0x13d/0x14c

During the cpu bringup, wakeup_cpu_via_init_nmi() is called and issues an
NMI on CPU 0.  The GHES NMI handler, ghes_notify_nmi() runs the
ghes_proc_irq_work work queue which ends up setting IRQ_WORK_VECTOR
(0xf6).  The "faulty" IR line set at arch/x86/kernel/apic/apic.c:1349 is  also
0xf6 (specifically APIC IRR for irqs 255 to 224 is 0x400000) which confirms
that something has set the IRQ_WORK_VECTOR line prior to the APIC being
initialized.

Commit 2383844d ("GHES: Elliminate double-loop in the NMI handler")
incorrectly modified the behavior such that the handler returns
NMI_HANDLED only if an error was processed, and incorrectly runs the ghes
work queue for every NMI.

This patch modifies the ghes_proc_irq_work() to run as it did prior to
2383844d ("GHES: Elliminate double-loop in the NMI handler") by
properly returning NMI_HANDLED and only calling the work queue if
NMI_HANDLED has been set.

Fixes: 2383844d (GHES: Elliminate double-loop in the NMI handler)
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Although ghes_proc() tests for errors while reading the error status,
it always return success (0). Fix this by propagating the return
value.

Fixes: d334a491 (ACPI, APEI, Generic Hardware Error Source memory error support)
Signed-of-by: NPunit Agrawal <punit.agrawa.@arm.com>
Tested-by: NTyler Baicar <tbaicar@codeaurora.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
[ rjw: Subject ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently the AER severity is calculated by calling cper_severity_to_aer(),
but the parameter sent is actually the GHES severity.  This causes the AER
severity to be incorrect.

Fix the parameter to be the CPER severity instead of the GHES severity.
Signed-off-by: NTyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NBorislav Petkov <bp@suse.de>