We will use this in the later patch for handling THP pages
Reviewed-by: NDavid Gibson <dwg@au1.ibm.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We now have pmd entries covering 16MB range and the PMD table double its original size.
We use the second half of the PMD table to deposit the pgtable (PTE page).
The depoisted PTE page is further used to track the HPTE information. The information
include [ secondary group | 3 bit hidx | valid ]. We use one byte per each HPTE entry.
With 16MB hugepage and 64K HPTE we need 256 entries and with 4K HPTE we need
4096 entries. Both will fit in a 4K PTE page. On hugepage invalidate we need to walk
the PTE page and invalidate all valid HPTEs.

This patch implements necessary arch specific functions for THP support and also
hugepage invalidate logic. These PMD related functions are intentionally kept
similar to their PTE counter-part.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

THP code does PTE page allocation along with large page request and deposit them
for later use. This is to ensure that we won't have any failures when we split
hugepages to regular pages.

On powerpc we want to use the deposited PTE page for storing hash pte slot and
secondary bit information for the HPTEs. We use the second half
of the pmd table to save the deposted PTE page.
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

If a hash bucket gets full, we "evict" a more/less random entry from it.
When we do that we don't invalidate the TLB (hpte_remove) because we assume
the old translation is still technically "valid". This implies that when
we are invalidating or updating pte, even if HPTE entry is not valid
we should do a tlb invalidate. With hugepages, we need to pass the correct
actual page size value for tlb invalidation.

This change update the patch 0608d692
"powerpc/mm: Always invalidate tlb on hpte invalidate and update" to handle
transparent hugepages correctly.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch creates debugfs entries (powerpc/PCIxxxx/err_injct) for
injecting EEH errors for testing purpose.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch creates one debugfs directory ("powerpc/PCIxxxx") for
each PHB so that we can hook EEH error injection debugfs entry
there in proceeding patch.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch registers OPAL event notifier and process the PCI errors
from firmware. If we have pending PCI errors, special EEH event
(without binding PE) will be sent to EEH core for processing.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While we're restarting or powering off the system, we needn't
the OPAL notifier any more. So just to disable that.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

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: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

It's meaningless to handle frozen PE if we already had fenced PHB.
The patch intends to check the PHB state before checking PE. If the
PHB has been put into fenced state, we need take care of that firstly.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch enables EEH check and let EEH core to process the EEH
errors for PowerNV platform while accessing config space. Originally,
the implementation already had mechanism to check EEH errors and
tried to recover from them. However, we never let EEH core to handle
the EEH errors.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch initializes EEH for PowerNV platform. Because the OPAL
APIs requires HUB ID, we need trace that through struct pnv_phb.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
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>

The patch implements the backend for EEH core to retrieve next
EEH error to handle. For the informational errors, we won't bother
the EEH core. Otherwise, the EEH should take appropriate actions
depending on the return value:

	0 - No further errors detected
	1 - Frozen PE
	2 - Fenced PHB
	3 - Dead PHB
	4 - Dead IOC
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch adds backends to retrieve error log and configure p2p
bridges for the indicated PE.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch adds the I/O chip backend to do PE reset. For now, we
focus on PCI bus dependent PE. If PHB PE has been put into error
state, the PHB will take complete reset. Besides, the root bridge
will take fundamental or hot reset accordingly if the indicated
PE locates at the toppest of PCI hierarchy tree. Otherwise, the
upstream p2p bridge will take hot reset.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch adds I/O chip backend to retrieve the state for the
indicated PE. While the PE state is temperarily unavailable,
the upper layer (powernv platform) should return default delay
(1 second).
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch adds the backend to enable or disable EEH functionality
for the specified PE. The backend is also used to enable MMIO or
DMA path for the problematic PE. It's notable that all PEs on
PowerNV platform support EEH functionality by default, and we
disallow to disable EEH for the specific PE.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The post initialization (struct eeh_ops::post_init) is called after
the EEH probe is done. On the other hand, the EEH core post
initialization is designed to call platform and then I/O chip backend
on PowerNV platform.

The patch adds the backend for I/O chip to notify the platform
that the specific PHB is ready to supply EEH service.
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>

The patch synchronizes OPAL APIs between kernel and firmware. Also,
we starts to replace opal_pci_get_phb_diag_data() with the similar
opal_pci_get_phb_diag_data2() and the former OPAL API would return
OPAL_UNSUPPORTED from now on.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On PowerNV platform, the EEH event caused by interrupt won't have
binding PE. The patch enables EEH core to handle the special event.
To avoid the current logic we have, The eeh_handle_event() is renamed
to eeh_handle_normal_event(), and the eeh_handle_special_event() is
introduced. The function eeh_handle_event() dispatches to above two
functions according to the input parameter. Besides, new backend
"next_error" added to eeh_ops and it's expected to have following
return values:

        4 - Dead IOC           3 - Dead PHB
        2 - Fenced PHB         1 - Frozen PE
        0 - No error found
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

An EEH event is created and queued to the event queue for each
ingress EEH error. When there're mutiple EEH errors, we need serialize
the process to keep consistent PE state (flags). The spinlock
"confirm_error_lock" was introduced for the purpose. We'll inject
EEH event upon error reporting interrupts on PowerNV platform. So
we export the spinlock for that to use for consistent PE state.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin 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: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We're not expecting that one specific PE got frozen for over 5
times in last hour. Otherwise, the PE will be removed from the
system upon newly coming EEH errors. The patch introduces time
stamp to trace the first error on specific PE in last hour and
function to update that accordingly. Besides, the time stamp
is recovered during PE hotplug path as we did for frozen count.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin 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: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While doing EEH recovery, the PCI devices of the problematic PE
should be removed and then added to the system again. During the
so-called hotplug event, the PCI devices of the problematic PE
will be probed through early/late phase. We would delay EEH probe
on late point for PowerNV platform since the PCI device isn't
available in early phase.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We shouldn't check that the returned PE status is exactly equal to
(EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE) but instead only check
that they are both set.

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

The patch adds new EEH operation post_init. It's used to notify
the platform that EEH core has completed the EEH probe. By that,
PowerNV platform starts to use the services supplied by EEH
functionality.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

For EEH on PowerNV platform, we will do EEH probe based on the
real PCI devices. The PCI devices are available after PCI probe.
So we have to call eeh_init() explicitly on PowerNV platform
after PCI probe. The patch also does EEH probe for PowerNV platform
in eeh_init().
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There're several types of PEs can be supported for now: PHB, Bus
and Device dependent PE. For PCI bus dependent PE, tracing the
corresponding PCI bus from PE (struct eeh_pe) would make the code
more efficient. The patch also enables the retrieval of PCI bus based
on the PCI bus dependent PE.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While processing EEH event interrupt from P7IOC, we need function
to retrieve the PE according to the indicated EEH device. The patch
makes function eeh_pe_get() public so that other source files can call
it for that purpose. Also, the patch fixes referring to wrong BDF
(Bus/Device/Function) address while searching PE in function
__eeh_pe_get().
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

One of the possible cases indicated by P7IOC interrupt is fenced
PHB. For that case, we need fetch the PE corresponding to the PHB
and disable the PHB and all subordinate PCI buses/devices, recover
from the fenced state and eventually enable the whole PHB. We need
one function to fetch the PHB PE outside eeh_pe.c and the patch is
going to make eeh_phb_pe_get() public for that purpose.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin 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: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Cleanup on EEH core to remove unnecessary whitespaces.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we only restore signals which are transactionally suspended but it's
possible that the transaction can be restored even when it's active.  Most
likely this will result in a transactional rollback by the hardware as the
transaction will have been doomed by an earlier treclaim.

The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel.  That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
assumptions based on having software rollback.

This changes the signal return code to always restore both contexts on 64 bit
signal return.  It also ensures that the MSR TM bits are properly restored from
the signal context which they are not currently.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we only restore signals which are transactionally suspended but it's
possible that the transaction can be restored even when it's active.  Most
likely this will result in a transactional rollback by the hardware as the
transaction will have been doomed by an earlier treclaim.

The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel.  That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
assumptions based on having software rollback.

This changes the signal return code to always restore both contexts on 32 bit
rt signal return.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently we clear out the MSR TM bits on signal return assuming that the
signal should never return to an active transaction.

This is bogus as the user may do this.  It's most likely the transaction will
be doomed due to a treclaim but that's a problem for the HW not the kernel.

The current code is a legacy of earlier kernel implementations which did
software rollback of active transactions in the kernel.  That code has now gone
but we didn't correctly fix up this part of the signals code which still makes
the assumption that it must be returning to a suspended transaction.

This pulls out both MSR TM bits from the user supplied context rather than just
setting TM suspend.  We pull out only the bits needed to ensure the user can't
do anything dangerous to the MSR.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently sys_sigreturn() is TM unaware.  Therefore, if we take a 32 bit signal
without SIGINFO (non RT) inside a transaction, on signal return we don't
restore the signal frame correctly.

This checks if the signal frame being restoring is an active transaction, and
if so, it copies the additional state to ptregs so it can be restored.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The MSR TM controls are in the top 32 bits of the MSR hence on 32 bit signals,
we stick the top half of the MSR in the checkpointed signal context so that the
user can access it.

Unfortunately, we don't currently write anything to the checkpointed signal
context when coming in a from a non transactional process and hence the top MSR
bits can contain junk.

This updates the 32 bit signal handling code to always write something to the
top MSR bits so that users know if the process is transactional or not and the
kernel can use it on signal return.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
cc: stable@vger.kernel.org (v3.9+)
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>