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

The patch introduces flag EEH_DEV_SYSFS to keep track that the sysfs
entries for the corresponding EEH device (then PCI device) has been
added or removed, in order to avoid race condition.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While restoring BARs for one specific PCI device, the pci_dev
instance should have been released. So it's not reliable to use
the pci_dev instance on restoring BARs. However, we still need
some information (e.g. PCIe capability position, header type) from
the pci_dev instance. So we have to store those information to
EEH device in advance.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When EEH error happens to one specific PE, some devices with drivers
supporting EEH won't except hotplug on the device. However, there
might have other deivces without driver, or with driver without EEH
support. For the case, we need do partial hotplug in order to make
sure that the PE becomes absolutely quite during reset. Otherise,
the PE reset might fail and leads to failure of error recovery.

The current code doesn't handle that 'mixed' case properly, it either
uses the error callbacks to the drivers, or tries hotplug, but doesn't
handle a PE (EEH domain) composed of a combination of the two.

The patch intends to support so-called "partial" hotplug for EEH:
Before we do reset, we stop and remove those PCI devices without
EEH sensitive driver. The corresponding EEH devices are not detached
from its PE, but with special flag. After the reset is done, those
EEH devices with the special flag will be scanned one by one.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

RTAS token "ibm,get-config-addr-info" or ibm,get-config-addr-info2"
are used to retrieve the PE address according to PCI address, which
made up of domain/bus/slot/function. If we don't have those 2 tokens,
the domain/bus/slot/function would be used as the address for EEH
RTAS operations. Some older f/w might not have those 2 tokens and
that blocks the EEH functionality to be initialized. It was introduced
by commit e2af155c ("powerpc/eeh: pseries platform EEH initialization").

The patch skips the check on those 2 tokens so we can bring up EEH
functionality successfully. And domain/bus/slot/function will be
used as address for EEH RTAS operations.

Cc: <stable@vger.kernel.org> # v3.4+
Reported-by: NRobert Knight <knight@princeton.edu>
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Tested-by: NRobert Knight <knight@princeton.edu>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

While EEH module is installed, PCI devices is checked one by one
to see if it supports eeh. On different platforms, the PCI devices
are referred through different ways when the EEH module is loaded.
For example, on pSeries platform, that is done by OF node. However,
we would do that by real PCI devices (struct pci_dev) on PowerNV
platform in future. So we needs some mechanism to differentiate
those cases by classifying them to probe modes, either from OF
nodes or real PCI devices.

The patch implements the support to eeh probe mode. Also, the
EEH on pSeries has set it into EEH_PROBE_MODE_DEVTREE. That means
the probe will be done based on OF nodes on pSeries platform.

In addition, On pSeries platform, it's done by OF nodes. The patch
moves the the probe function from EEH core to platform dependent
backend and some cleanup applied.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Originally, all the EEH operations were implemented based on OF node.

Actually, it explicitly breaks the rules that the operation target
is PE instead of device. Therefore, the patch makes all the operations
based on PE instead of device.

Unfortunately, the backend for config space has to be kept as original
because it doesn't depend on PE.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The patch adds more logs to EEH initialization functions for
debugging purpose. Also, the machine type (pSeries) is checked
in the platform initialization to assure it's the correct platform
to invoke it.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently, we have 3 phases for EEH initialization on pSeries platform.
All of them are done through builtin functions: platform initialization,
EEH device creation, and EEH subsystem enablement. All of them are done
no later than ppc_md.setup_arch. That means that the slab/slub isn't ready
yet, so we have to allocate memory chunks on basis of PAGE_SIZE for those
dynamically created EEH devices. That's pretty expensive.

In order to utilize slab/slub for memory allocation, we have to move the EEH
initialization functions around, but all of them should be called after slab
is ready.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

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

With the original EEH implementation, the access to config space of
the corresponding PCI device is done by RTAS sensitive function. That
depends on pci_dn heavily. That would limit EEH extension to other
platforms like powernv because other platforms might have different
ways to access PCI config space.

The patch splits those functions used to access PCI config space
and implement them in platform related EEH component. It would be
helpful to support EEH on multiple platforms simutaneously in future.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The pci_dn has been replaced with eeh_dev. In order to comply with
the rule, the EEH platform implementation on pSeries should also
be adjusted for a little bit so that it will depend on eeh_dev instead
of pci_dn.

The patch replaces pci_dn with eeh_dev. The corresponding information
will be retrieved from eeh_dev instead of pci_dn.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

In order to enable particular PCI device, which has been included
in the parent PE. The involved PCI bridges should be enabled explicitly
if there has. On pSeries platform, there're dedicated RTAS calls
to fulfil the purpose.

The patch implements the function of configuring PCI bridges through
the dedicated RTAS calls. Besides, the function has been abstracted
by struct eeh_ops::configure_bridge so that the EEH core components
could support multiple platforms in future.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On RTAS compliant pSeries platform, one dedicated RTAS call has
been introduced to retrieve EEH temporary or permanent error log.

The patch implements the function of retriving EEH error log through
RTAS call. Besides, it has been abstracted by struct eeh_ops::get_log
so that EEH core components could support multiple platforms in future.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On RTAS compliant pSeries platform, there is a dedicated RTAS call
(ibm,set-slot-reset) to reset the specified PE. Furthermore, two
types of resets are supported: hot and fundamental. the type of
reset is to be used actually depends on the included PCI device's
requirements.

The patch implements resetting PE on pSeries platform through RTAS
call. Besides, it has been abstracted through struct eeh_ops::reset
so that EEH core components could support multiple platforms in future.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On pSeries platform, the PE state might be temporarily unavailable.
In that case, the firmware will return the corresponding wait time.
That means the kernel has to wait for appropriate time in order to
get the PE state.

The patch does the implementation for that. Besides, the function
has been abstracted through struct eeh_ops::wait_state so that EEH core
components could support multiple platforms in future.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

On pSeries platform, there're 2 dedicated RTAS calls introduced to
retrieve the corresponding PE's state: ibm,read-slot-reset-state and
ibm,read-slot-reset-state2.

The patch implements the retrieval of PE's state according to the
given PE address. Besides, the implementation has been abstracted by
struct eeh_ops::get_state so that EEH core components could support
multiple platforms in future.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There're 2 types of addresses used for EEH operations. The first
one would be BDF (Bus/Device/Function) address which is retrieved
from the reg property of the corresponding FDT node. Another one
is PE address that should be enquired from firmware through RTAS
call on pSeries platform. When issuing EEH operation, the PE address
has precedence over BDF address.

The patch implements retrieving PE address according to the given
BDF address on pSeries platform. Also, the struct eeh_early_enable_info
has been removed since the information can be figured out from
dn->pdn->phb->buid directly and that simplifies the code.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There're 4 EEH operations that are covered by the dedicated RTAS
call <ibm,set-eeh-option>: enable or disable EEH, enable MMIO and
enable DMA. At early stage of system boot, the EEH would be tried
to enable on PCI device related device node. MMIO and DMA for
particular PE should be enabled when doing recovery on EEH errors
so that the PE could function properly again.

The patch implements it and abstract that through struct
eeh_ops::set_eeh. It would be help for EEH to support multiple
platforms in future.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The platform specific EEH operations have been abstracted by
struct eeh_ops. The individual platroms, including pSeries, needs
doing necessary initialization before the platform dependent EEH
operations work properly.

The patch is addressing that and do necessary platform initialization
for pSeries platform. More specificly, it will figure out the tokens
of EEH related RTAS calls.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

EEH has been implemented on RTAS-compliant pSeries platform.
That's to say, the EEH operations will be implemented through RTAS
calls eventually. The situation limited feasible extension on EEH.
In order to support EEH on multiple platforms like pseries and powernv
simutaneously. We have to split the platform dependent EEH options
up out of current implementation.

The patch addresses supporting EEH on multiple platforms. The pseries
platform dependent EEH operations will be abstracted by struct eeh_ops.
EEH core components will be built based on the registered EEH operations.
With the mechanism, what the individual platform needs to do is implement
platform dependent EEH operations.

For now, the pseries platform is covered under the mechanism. That means
we have to think about other platforms to support EEH, like powernv.
Besides, we only have framework for the mechanism and we have to implement
it for pseries platform later.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>