This patch adds a debugfs interface to force scheduling a recovery event.
This can be used to recover a specific PE or schedule a "special" recovery
even that checks for errors at the PHB level.
To force a recovery of a normal PE, use:
echo '<#pe>:<#phb>' > /sys/kernel/debug/powerpc/eeh_force_recover
To force a scan for broken PHBs:
echo 'hwcheck' > /sys/kernel/debug/powerpc/eeh_force_recover
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently when we detect an error we automatically invoke the EEH recovery
handler. This can be annoying when debugging EEH problems, or when working
on EEH itself so this patch adds a debugfs knob that will prevent a
recovery event from being queued up when an issue is detected.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For this use case, completions and semaphores are equivalent,
but semaphores are an awkward interface that should generally
be avoided, so use the completion instead.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the EEH_PE_RECOVERING flag for a PE is managed by both the
caller and callee of eeh_handle_normal_event() (among other places not
considered here). This is complicated by the fact that the PE may
or may not have been invalidated by the call.
So move the callee's handling into eeh_handle_normal_event(), which
clarifies it and allows the return type to be changed to void (because
it no longer needs to indicate at the PE has been invalidated).
This should not change behaviour except in eeh_event_handler() where
it was previously possible to cause eeh_pe_state_clear() to be called
on an invalid PE, which is now avoided.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The function eeh_handle_event(pe) does nothing other than switching
between calling eeh_handle_normal_event(pe) and
eeh_handle_special_event(). However it is only called in two places,
one where pe can't be NULL and the other where it must be NULL (see
eeh_event_handler()) so it does nothing but obscure the flow of
control.
So, remove it.
Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
PHB, PE (and by association MVE) numbers are printed as a mix of decimal
and hexadecimal throughout the kernel. This can be misleading, so make
them all hexadecimal.
Standardising on hex instead of dec because:
- PHB numbers are presented in hex in sysfs/debugfs (and lspci, etc)
- PE numbers are presented as hex in sysfs and parsed in hex in debugfs
The only place I think this could cause confusing are the messages during
boot, i.e.
pci 000a:01 : [PE# 000] Secondary bus 1 associated with PE#0
which can be a quick way to check PE numbers. pe_level_printk() will
only print two characters instead of three, so the above would be
pci 000a:01 : [PE# 00] Secondary bus 1 associated with PE#0
which gives a hint it's in hex.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
As sparse suggests, these should be made static.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On PowerNV platform, EEH errors are reported by IO accessors or poller
driven by interrupt. After the PE is isolated, we won't produce EEH
event for the PE. The current implementation has possibility of EEH
event lost in this way:
The interrupt handler queues one "special" event, which drives the poller.
EEH thread doesn't pick the special event yet. IO accessors kicks in, the
frozen PE is marked as "isolated" and EEH event is queued to the list.
EEH thread runs because of special event and purge all existing EEH events.
However, we never produce an other EEH event for the frozen PE. Eventually,
the PE is marked as "isolated" and we don't have EEH event to recover it.
The patch fixes the issue to keep EEH events for PEs that have been
marked as "isolated" with the help of additional "force" help to
eeh_remove_event().
Reported-by: Rolf Brudeseth <rolfb@us.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This clarifies in the log whether the error is a global PHB error
or an individual PE being frozen.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To replace down() with down_interrutible() to avoid following
warning:
[c00000007ba7b710] [c000000000014410] .__switch_to+0x1b0/0x380
[c00000007ba7b7c0] [c0000000007b408c] .__schedule+0x3ec/0x970
[c00000007ba7ba50] [c0000000007b1f24] .schedule_timeout+0x1a4/0x2b0
[c00000007ba7bb30] [c0000000007b34a4] .__down+0xa4/0x104
[c00000007ba7bbf0] [c0000000000b9230] .down+0x60/0x70
[c00000007ba7bc80] [c0000000000336d0] .eeh_event_handler+0x70/0x190
[c00000007ba7bd30] [c0000000000b1a58] .kthread+0xe8/0xf0
[c00000007ba7be30] [c00000000000a05c] .ret_from_kernel_thread+0x5c/0x8
This also avoids keeping the load average up while doing nothing.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On PowerNV platform, we might run into the situation where subsequent
events are duplicated events of former one, which is being processed.
For the case, we need the function implemented by the patch to purge
EEH events accordingly.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We possiblly have multiple kthreads running for multiple EEH errors
(events) and use one spinlock to make the process of handling those
EEH events serialized. That's unnecessary and the patch creates only
one kthread, which is started during EEH core initialization time in
eeh_init(). A new semaphore introduced to count the number of existing
EEH events in the queue and the kthread waiting on the semaphore.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The patch moves the common part of EEH core into arch/powerpc/kernel
directory so that we needn't PPC_PSERIES while compiling POWERNV
platform:
* Move the EEH common part into arch/powerpc/kernel
* Move the functions for PCI hotplug from pSeries platform to
arch/powerpc/kernel/pci-hotplug.c
* Move CONFIG_EEH from arch/powerpc/platforms/pseries/Kconfig to
arch/powerpc/platforms/Kconfig
* Adjust makefile accordingly
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
