If a PCI device's current driver implements the error handling callbacks
EEH can use them to recover the device after an error occurs. For devices
without the error handling callbacks we recover them by removing the device
and re-scanning it so the PCI core puts the device back into a known good
state.
Currently there's no way for userspace to determine if the driver supports
recovery or not which makes it difficult to write automated tests for EEH.
This patch addressing that by adding a debugfs interface for querying if
a specific device can be recovered or not.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201103051512.919333-2-oohall@gmail.com
In commit 269e583357 ("powerpc/eeh: Delete eeh_pe->config_addr") the
following simplification was made:
- if (!pe->addr && !pe->config_addr) {
+ if (!pe->addr) {
eeh_stats.no_cfg_addr++;
return 0;
}
This introduced a bug which causes EEH checking to be skipped for
devices in PE#0.
Before the change above the check would always pass since at least one
of the two PE addresses would be non-zero in all circumstances. On
PowerNV pe->config_addr would be the BDFN of the first device added to
the PE. The zero BDFN is reserved for the PHB's root port, but this is
fine since for obscure platform reasons the root port is never
assigned to PE#0.
Similarly, on pseries pe->addr has always been non-zero for the
reasons outlined in commit 42de19d5ef ("powerpc/pseries/eeh: Allow
zero to be a valid PE configuration address").
We can fix the problem by deleting the block entirely The original
purpose of this test was to avoid performing EEH checks on devices
that were not on an EEH capable bus. In modern Linux the edev->pe
pointer will be NULL for devices that are not on an EEH capable bus.
The code block immediately above this one already checks for the
edev->pe == NULL case so this test (new and old) is entirely
redundant.
Ideally we'd delete eeh_stats.no_cfg_addr too since nothing increments
it any more. Unfortunately, that information is exposed via
/proc/powerpc/eeh which means it's technically ABI. We could make it
hard-coded, but that's a change for another patch.
Fixes: 269e583357 ("powerpc/eeh: Delete eeh_pe->config_addr")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201021232554.1434687-1-oohall@gmail.com
The eeh_pe->config_addr field was supposed to be removed in
commit 35d64734b6 ("powerpc/eeh: Clean up PE addressing") which made it
largely unused. Finish the job.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201007040903.819081-1-oohall@gmail.com
When support for EEH on PowerNV was added a lot of pseries specific code
was made "generic" and some of the quirks of pseries EEH came along for the
ride. One of the stranger quirks is eeh_pe containing two types of PE
address: pe->addr and pe->config_addr. There reason for this appears to be
historical baggage rather than any real requirements.
On pseries EEH PEs are manipulated using RTAS calls. Each EEH RTAS call
takes a "PE configuration address" as an input which is used to identify
which EEH PE is being manipulated by the call. When initialising the EEH
state for a device the first thing we need to do is determine the
configuration address for the PE which contains the device so we can enable
EEH on that PE. This process is outlined in PAPR which is the modern
(i.e post-2003) FW specification for pseries. However, EEH support was
first described in the pSeries RISC Platform Architecture (RPA) and
although they are mostly compatible EEH is one of the areas where they are
not.
The major difference is that RPA doesn't actually have the concept of a PE.
On RPA systems the EEH RTAS calls are done on a per-device basis using the
same config_addr that would be passed to the RTAS functions to access PCI
config space (e.g. ibm,read-pci-config). The config_addr is not identical
since the function and config register offsets of the config_addr must be
set to zero. EEH operations being done on a per-device basis doesn't make a
whole lot of sense when you consider how EEH was implemented on legacy PCI
systems.
For legacy PCI(-X) systems EEH was implemented using special PCI-PCI
bridges which contained logic to detect errors and freeze the secondary
bus when one occurred. This means that the EEH enabled state is shared
among all devices behind that EEH bridge. As a result there's no way to
implement the per-device control required for the semantics specified by
RPA. It can be made to work if we assume that a separate EEH bridge exists
for each EEH capable PCI slot and there are no bridges behind those slots.
However, RPA also specifies the ibm,configure-bridge RTAS call for
re-initalising bridges behind EEH capable slots after they are reset due
to an EEH event so that is probably not a valid assumption. This
incoherence was fixed in later PAPR, which succeeded RPA. Unfortunately,
since Linux EEH support seems to have been implemented based on the RPA
spec some of the legacy assumptions were carried over (probably for POWER4
compatibility).
The fix made in PAPR was the introduction of the "PE" concept and
redefining the EEH RTAS calls (set-eeh-option, reset-slot, etc) to operate
on a per-PE basis so all devices behind an EEH bride would share the same
EEH state. The "config_addr" argument to the EEH RTAS calls became the
"PE_config_addr" and the OS was required to use the
ibm,get-config-addr-info RTAS call to find the correct PE address for the
device. When support for the new interfaces was added to Linux it was
implemented using something like:
At probe time:
pdn->eeh_config_addr = rtas_config_addr(pdn);
pdn->eeh_pe_config_addr = rtas_get_config_addr_info(pdn);
When performing an RTAS call:
config_addr = pdn->eeh_config_addr;
if (pdn->eeh_pe_config_addr)
config_addr = pdn->eeh_pe_config_addr;
rtas_call(..., config_addr, ...);
In other words, if the ibm,get-config-addr-info RTAS call is implemented
and returned a valid result we'd use that as the argument to the EEH
RTAS calls. If not, Linux would fall back to using the device's
config_addr. Over time these addresses have moved around going from pci_dn
to eeh_dev and finally into eeh_pe. Today the users look like this:
config_addr = pe->config_addr;
if (pe->addr)
config_addr = pe->addr;
rtas_call(..., config_addr, ...);
However, considering the EEH core always operates on a per-PE basis and
even on pseries the only per-device operation is the initial call to
ibm,set-eeh-option I'm not sure if any of this actually works on an RPA
system today. It doesn't make much sense to have the fallback address in
a generic structure either since the bulk of the code which reference it
is in pseries anyway.
The EEH core makes a token effort to support looking up a PE using the
config_addr by having two arguments to eeh_pe_get(). However, a survey of
all the callers to eeh_pe_get() shows that all bar one have the config_addr
argument hard-coded to zero.The only caller that doesn't is in
eeh_pe_tree_insert() which has:
if (!eeh_has_flag(EEH_VALID_PE_ZERO) && !edev->pe_config_addr)
return -EINVAL;
pe = eeh_pe_get(hose, edev->pe_config_addr, edev->bdfn);
The third argument (config_addr) is only used if the second (pe->addr)
argument is invalid. The preceding check ensures that the call to
eeh_pe_get() will never happen if edev->pe_config_addr is invalid so there
is no situation where eeh_pe_get() will search for a PE based on the 3rd
argument. The check also means that we'll never insert a PE into the tree
where pe_config_addr is zero since EEH_VALID_PE_ZERO is never set on
pseries. All the users of the fallback address on pseries never actually
use the fallback and all the only caller that supplies something for the
config_addr argument to eeh_pe_get() never use it either. It's all dead
code.
This patch removes the fallback address from eeh_pe since nothing uses it.
Specificly, we do this by:
1) Removing pe->config_addr
2) Removing the EEH_VALID_PE_ZERO flag
3) Removing the fallback address argument to eeh_pe_get().
4) Removing all the checks for pe->addr being zero in the pseries EEH code.
This leaves us with PE's only being identified by what's in their pe->addr
field and the EEH core relying on the platform to ensure that eeh_dev's are
only inserted into the EEH tree if they're actually inside a PE.
No functional changes, I hope.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-9-oohall@gmail.com
The initialisation of EEH mostly happens in a core_initcall_sync initcall,
followed by registering a bus notifier later on in an arch_initcall.
Anything involving initcall dependecies is mostly incomprehensible unless
you've spent a while staring at code so here's the full sequence:
ppc_md.setup_arch <-- pci_controllers are created here
...time passes...
core_initcall <-- pci_dns are created from DT nodes
core_initcall_sync <-- platforms call eeh_init()
postcore_initcall <-- PCI bus type is registered
postcore_initcall_sync
arch_initcall <-- EEH pci_bus notifier registered
subsys_initcall <-- PHBs are scanned here
There's no real requirement to do the EEH setup at the core_initcall_sync
level. It just needs to be done after pci_dn's are created and before we
start scanning PHBs. Simplify the flow a bit by moving the platform EEH
inititalisation to an arch_initcall so we can fold the bus notifier
registration into eeh_init().
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-5-oohall@gmail.com
No longer used since the platforms perform their EEH initialisation before
calling eeh_init().
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-4-oohall@gmail.com
Drop the EEH register / unregister ops thing and have the platform pass the
ops structure into eeh_init() directly. This takes one initcall out of the
EEH setup path and it means we're only doing EEH setup on the platforms
which actually support it. It's also less code and generally easier to
follow.
No functional changes.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200918093050.37344-1-oohall@gmail.com
The naming of eeh_{add_to|remove_from}_parent_pe() doesn't really reflect
what they actually do. If the PE referred to be edev->pe_config_addr
already exists under that PHB then the edev is added to that PE. However,
if the PE doesn't exist the a new one is created for the edev.
The bulk of the implementation of eeh_add_to_parent_pe() covers that
second case. Similarly, most of eeh_remove_from_parent_pe() is
determining when it's safe to delete a PE.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-12-oohall@gmail.com
Mechanical conversion of the eeh_ops interfaces to use eeh_dev to reference
a specific device rather than pci_dn. No functional changes.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-9-oohall@gmail.com
Mechanical conversion of the eeh_ops interfaces to use eeh_dev to reference
a specific device rather than pci_dn. No functional changes.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-7-oohall@gmail.com
There's a bunch of strange things about this code. First up is that none of
the fields being written to are functional for a VF. The SR-IOV
specification lists then as "Reserved, but OS should preserve" so writing
new values to them doesn't do anything and is clearly wrong from a
correctness perspective.
However, since VFs are designed to be managed by the OS there is an
argument to be made that we should be saving and restoring some parts of
config space. We already sort of do that by saving the first 64 bytes of
config space in the eeh_dev (see eeh_dev->config_space[]). This is
inadequate since it doesn't even consider saving and restoring the PCI
capability structures. However, this is a problem with EEH in general and
that needs to be fixed for non-VF devices too.
There's no real reason to keep around this around so delete it.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-6-oohall@gmail.com
This function is a one line wrapper around eeh_phb_pe_create() and despite
the name it doesn't create any eeh_dev structures. Replace it with direct
calls to eeh_phb_pe_create() since that does what it says on the tin
and removes a layer of indirection.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-1-oohall@gmail.com
EEH device state is currently removed (by eeh_remove_device()) during
the device release handler, which is invoked as the device's reference
count drops to zero. This may take some time, or forever, as other
threads may hold references.
However, the PCI device state is released synchronously by
pci_stop_and_remove_bus_device(). This mismatch causes problems, for
example the device may be re-discovered as a new device before the
release handler has been called, leaving the PCI and EEH state
mismatched.
So instead, call eeh_remove_device() from the bus device removal
handlers, which are called synchronously in the removal path.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0a1f5105d3a33b1c090bba31de63eb0cdd25de7b.1588045502.git.sbobroff@linux.ibm.com
With the EEH early probe now being pseries specific there's no need for
eeh_ops->probe() to take a pci_dn. Instead, we can make it take a pci_dev
and use the probe function to map a pci_dev to an eeh_dev. This allows
the platform to implement it's own method for finding (or creating) an
eeh_dev for a given pci_dev which also removes a use of pci_dn in
generic EEH code.
This patch also renames eeh_device_add_late() to eeh_device_probe(). This
better reflects what it does does and removes the last vestiges of the
early/late EEH probe split.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-6-oohall@gmail.com
The eeh_ops->probe() function is called from two different contexts:
1. On pseries, where we set EEH_PROBE_MODE_DEVTREE, it's called in
eeh_add_device_early() which is supposed to run before we create
a pci_dev.
2. On PowerNV, where we set EEH_PROBE_MODE_DEV, it's called in
eeh_device_add_late() which is supposed to run *after* the
pci_dev is created.
The "early" probe is required because PAPR requires that we perform an RTAS
call to enable EEH support on a device before we start interacting with it
via config space or MMIO. This requirement doesn't exist on PowerNV and
shoehorning two completely separate initialisation paths into a common
interface just results in a convoluted code everywhere.
Additionally the early probe requires the probe function to take an pci_dn
rather than a pci_dev argument. We'd like to make pci_dn a pseries specific
data structure since there's no real requirement for them on PowerNV. To
help both goals move the early probe into the pseries containment zone
so the platform depedence is more explicit.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-5-oohall@gmail.com
This check for a missing PHB has existing in various forms since the
initial PPC64 port was upstreamed in 2002. The idea seems to be that we
need to guard against creating pci-specific data structures for the non-pci
children of a PCI device tree node (e.g. USB devices). However, we only
create pci_dn structures for DT nodes that correspond to PCI devices so
there's not much point in doing this check in the eeh_probe path.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-4-oohall@gmail.com
On pseries and PowerNV pcibios_bus_add_device() calls eeh_add_device_late()
so there's no need to do a separate tree traversal to bind the eeh_dev and
pci_dev together setting up the PHB at boot. As a result we can remove
eeh_add_device_tree_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-2-oohall@gmail.com
Move creating the EEH specific sysfs files into eeh_add_device_late()
rather than being open-coded all over the place. Calling the function is
generally done immediately after calling eeh_add_device_late() anyway. This
is also a correctness fix since currently the sysfs files will be added
even if the EEH probe happens to fail.
Similarly, on pseries we currently add the sysfs files before calling
eeh_add_device_late(). This is flat-out broken since the sysfs files
require the pci_dev->dev.archdata.edev pointer to be set, and that is done
in eeh_add_device_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-1-oohall@gmail.com
Many drivers don't check for errors when they get a 0xFFs response from an
MMIO load. As a result after an EEH event occurs a driver can get stuck in
a polling loop unless it some kind of internal timeout logic.
Currently EEH tries to detect and report stuck drivers by dumping a stack
trace after eeh_dev_check_failure() is called EEH_MAX_FAILS times on an
already frozen PE. The value of EEH_MAX_FAILS was chosen so that a dump
would occur every few seconds if the driver was spinning in a loop. This
results in a lot of spurious stack traces in the kernel log.
Fix this by limiting it to printing one stack trace for each PE freeze. If
the driver is truely stuck the kernel's hung task detector is better suited
to reporting the probelm anyway.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191016012536.22588-1-oohall@gmail.com
The eeh_sysfs_remove_device() function is supposed to clear the
EEH_DEV_SYSFS flag since it indicates the EEH sysfs entries have been added
for a pci_dev.
When the sysfs files are removed eeh_remove_device() the eeh_dev and the
pci_dev have already been de-associated. This then causes the
pci_dev_to_eeh_dev() call in eeh_sysfs_remove_device() to return NULL so
the flag can't be cleared from the still-live eeh_dev. This problem is
worked around in the caller by clearing the flag manually. However, this
behaviour doesn't make a whole lot of sense, so this patch fixes it by:
a) Re-ordering eeh_remove_device() so that eeh_sysfs_remove_device() is
called before de-associating the pci_dev and eeh_dev.
b) Making eeh_sysfs_remove_device() emit a warning if there's no
corresponding eeh_dev for a pci_dev. The paths where the sysfs
files are only reachable if EEH was setup for the device
for the device in the first place so hitting this warning
indicates a programming error.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Tested-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-6-oohall@gmail.com
Add an interface to debugfs for generating an EEH event on a given device.
This works by disabling memory accesses to and from the device by setting
the PCI_COMMAND register (or the VF Memory Space Enable on the parent PF).
This is a somewhat portable alternative to using the platform specific
error injection mechanisms since those tend to be either hard to use, or
straight up broken. For pseries the interfaces also requires the use of
/dev/mem which is probably going to go away in a post-LOCKDOWN world
(and it's a horrific hack to begin with) so moving to a kernel-provided
interface makes sense and provides a sane, cross-platform interface for
userspace so we can write more generic testing scripts.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903101605.2890-14-oohall@gmail.com
Detecting an frozen EEH PE usually occurs when an MMIO load returns a 0xFFs
response. When performing EEH testing using the EEH error injection feature
available on some platforms there is no simple way to kick-off the kernel's
recovery process since any accesses from userspace (usually /dev/mem) will
bypass the MMIO helpers in the kernel which check if a 0xFF response is due
to an EEH freeze or not.
If a device contains a 0xFF byte in it's config space it's possible to
trigger the recovery process via config space read from userspace, but this
is not a reliable method. If a driver is bound to the device an in use it
will frequently trigger the MMIO check, but this is also inconsistent.
To solve these problems this patch adds a debugfs file called
"eeh_dev_check" which accepts a <domain>:<bus>:<dev>.<fn> string and runs
eeh_dev_check_failure() on it. This is the same check that's done when the
kernel gets a 0xFF result from an config or MMIO read with the added
benifit that it can be reliably triggered from userspace.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903101605.2890-13-oohall@gmail.com
Currently we print a stack trace in the event handler to help with
debugging EEH issues. In the case of suprise hot-unplug this is unneeded,
so we want to prevent printing the stack trace unless we know it's due to
an actual device error. To accomplish this, we can save a stack trace at
the point of detection and only print it once the EEH recovery handler has
determined the freeze was due to an actual error.
Since the whole point of this is to prevent spurious EEH output we also
move a few prints out of the detection thread, or mark them as pr_debug
so anyone interested can get output from the eeh_check_dev_failure()
if they want.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903101605.2890-6-oohall@gmail.com
Convert existing messages, where appropriate, to use the eeh_edev_*
logging macros.
The only effect should be minor adjustments to the log messages, apart
from:
- A new message in pseries_eeh_probe() "Probing device" to match the
powernv case.
- The "Probing device" message in pnv_eeh_probe() is now generated
slightly later, which will mean that it is no longer emitted for
devices that aren't probed due to the initial checks.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ce505a0a7a4a5b0367f0f40f8b26e7c0a9cf4cb7.1565930772.git.sbobroff@linux.ibm.com
Now that EEH support for all devices (on PowerNV and pSeries) is
provided by the pcibios bus add device hooks, eeh_probe_devices() and
eeh_addr_cache_build() are redundant and can be removed.
Move the EEH enabled message into it's own function so that it can be
called from multiple places.
Note that previously on pSeries, useless EEH sysfs files were created
for some devices that did not have EEH support and this change
prevents them from being created.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/33b0a6339d5ac88693de092d6fba984f2a5add66.1565930772.git.sbobroff@linux.ibm.com
On PowerNV and pSeries, devices currently acquire EEH support from
several different places: Boot-time devices from eeh_probe_devices()
and eeh_addr_cache_build(), Virtual Function devices from the pcibios
bus add device hooks and hot plugged devices from pci_hp_add_devices()
(with other platforms using other methods as well). Unfortunately,
pSeries machines currently discover hot plugged devices using
pci_rescan_bus(), not pci_hp_add_devices(), and so those devices do
not receive EEH support.
Rather than adding another case for pci_rescan_bus(), this change
widens the scope of the pcibios bus add device hooks so that they can
handle all devices. As a side effect this also supports devices
discovered after manually rescanning via /sys/bus/pci/rescan.
Note that on PowerNV, this change allows the EEH subsystem to become
enabled after boot as long as it has not been forced off, which was
not previously possible (it was already possible on pSeries).
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/72ae8ae9c54097158894a52de23690448de38ea9.1565930772.git.sbobroff@linux.ibm.com
The EEH address cache is currently initialized and populated by a
single function: eeh_addr_cache_build(). While the initial population
of the cache can only be done once resources are allocated,
initialization (just setting up a spinlock) could be done much
earlier.
So move the initialization step into a separate function and call it
from a core_initcall (rather than a subsys initcall).
This will allow future work to make use of the cache during boot time
PCI scanning.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0557206741bffee76cdfff042f65321f6f7a5b41.1565930772.git.sbobroff@linux.ibm.com
Notable changes:
- Removal of the NPU DMA code, used by the out-of-tree Nvidia driver, as well
as some other functions only used by drivers that haven't (yet?) made it
upstream.
- A fix for a bug in our handling of hardware watchpoints (eg. perf record -e
mem: ...) which could lead to register corruption and kernel crashes.
- Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for vmalloc
when using the Radix MMU.
- A large but incremental rewrite of our exception handling code to use gas
macros rather than multiple levels of nested CPP macros.
And the usual small fixes, cleanups and improvements.
Thanks to:
Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab, Aneesh Kumar K.V, Anju
T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Cédric Le Goater,
Christian Lamparter, Christophe Leroy, Christophe Lombard, Christoph Hellwig,
Daniel Axtens, Denis Efremov, Enrico Weigelt, Frederic Barrat, Gautham R.
Shenoy, Geert Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg
Kurz, Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N. Rao,
Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi Bangoria,
Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher Boessenkool, Shaokun
Zhang, Shawn Anastasio, Stewart Smith, Suraj Jitindar Singh, Thiago Jung
Bauermann, YueHaibing.
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Merge tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Notable changes:
- Removal of the NPU DMA code, used by the out-of-tree Nvidia driver,
as well as some other functions only used by drivers that haven't
(yet?) made it upstream.
- A fix for a bug in our handling of hardware watchpoints (eg. perf
record -e mem: ...) which could lead to register corruption and
kernel crashes.
- Enable HAVE_ARCH_HUGE_VMAP, which allows us to use large pages for
vmalloc when using the Radix MMU.
- A large but incremental rewrite of our exception handling code to
use gas macros rather than multiple levels of nested CPP macros.
And the usual small fixes, cleanups and improvements.
Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Andreas Schwab,
Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann,
Athira Rajeev, Cédric Le Goater, Christian Lamparter, Christophe
Leroy, Christophe Lombard, Christoph Hellwig, Daniel Axtens, Denis
Efremov, Enrico Weigelt, Frederic Barrat, Gautham R. Shenoy, Geert
Uytterhoeven, Geliang Tang, Gen Zhang, Greg Kroah-Hartman, Greg Kurz,
Gustavo Romero, Krzysztof Kozlowski, Madhavan Srinivasan, Masahiro
Yamada, Mathieu Malaterre, Michael Neuling, Nathan Lynch, Naveen N.
Rao, Nicholas Piggin, Nishad Kamdar, Oliver O'Halloran, Qian Cai, Ravi
Bangoria, Sachin Sant, Sam Bobroff, Satheesh Rajendran, Segher
Boessenkool, Shaokun Zhang, Shawn Anastasio, Stewart Smith, Suraj
Jitindar Singh, Thiago Jung Bauermann, YueHaibing"
* tag 'powerpc-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (163 commits)
powerpc/powernv/idle: Fix restore of SPRN_LDBAR for POWER9 stop state.
powerpc/eeh: Handle hugepages in ioremap space
ocxl: Update for AFU descriptor template version 1.1
powerpc/boot: pass CONFIG options in a simpler and more robust way
powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h
powerpc/irq: Don't WARN continuously in arch_local_irq_restore()
powerpc/module64: Use symbolic instructions names.
powerpc/module32: Use symbolic instructions names.
powerpc: Move PPC_HA() PPC_HI() and PPC_LO() to ppc-opcode.h
powerpc/module64: Fix comment in R_PPC64_ENTRY handling
powerpc/boot: Add lzo support for uImage
powerpc/boot: Add lzma support for uImage
powerpc/boot: don't force gzipped uImage
powerpc/8xx: Add microcode patch to move SMC parameter RAM.
powerpc/8xx: Use IO accessors in microcode programming.
powerpc/8xx: replace #ifdefs by IS_ENABLED() in microcode.c
powerpc/8xx: refactor programming of microcode CPM params.
powerpc/8xx: refactor printing of microcode patch name.
powerpc/8xx: Refactor microcode write
powerpc/8xx: refactor writing of CPM microcode arrays
...
In commit 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap
space") support for using hugepages in the vmalloc and ioremap areas was
enabled for radix. Unfortunately this broke EEH MMIO error checking.
Detection works by inserting a hook which checks the results of the
ioreadXX() set of functions. When a read returns a 0xFFs response we
need to check for an error which we do by mapping the (virtual) MMIO
address back to a physical address, then mapping physical address to a
PCI device via an interval tree.
When translating virt -> phys we currently assume the ioremap space is
only populated by PAGE_SIZE mappings. If a hugepage mapping is found we
emit a WARN_ON(), but otherwise handles the check as though a normal
page was found. In pathalogical cases such as copying a buffer
containing a lot of 0xFFs from BAR memory this can result in the system
not booting because it's too busy printing WARN_ON()s.
There's no real reason to assume huge pages can't be present and we're
prefectly capable of handling them, so do that.
Fixes: 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap space")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190710150517.27114-1-oohall@gmail.com
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Adds a debugfs file that can be read to view the contents of the EEH
address cache. This is pretty similar to the existing
eeh_addr_cache_print() function, but that function is intended to debug
issues inside of the kernel since it's #ifdef`ed out by default, and writes
into the kernel log.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
There's no need to the custom getter/setter functions so we should remove
them in favour of using the generic one. While we're here, change the type
of eeh_max_freeze to u32 and print the value in decimal rather than
hex because printing it in hex makes no sense.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, eeh_pe_reset_full() will only attempt to reset a PE more
than once if activating the reset state and deactivating it both
succeed, but later polling shows that it hasn't become active.
Change this so that it will try up to three times for any reason other
than an unrecoverable slot error and adjust the message generation so
that it's clear weather the reset has ultimately succeeded or failed.
This allows the reset to succeed in some situations where it would
currently fail.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, the EEH recovery process considers passed-through devices
as if they were not EEH-aware, which can cause them to be removed as
part of recovery. Because device removal requires cooperation from
the guest, this may lead to the process stalling or deadlocking.
Also, if devices are removed on the host side, they will be removed
from their IOMMU group, making recovery in the guest impossible.
Therefore, alter the recovery process so that passed-through devices
are not removed but are instead left frozen (and marked isolated)
until the guest performs it's own recovery. If firmware thaws a
passed-through PE because it's parent PE has been thawed (because it
was not passed through), re-freeze it.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add a parameter to eeh_pe_state_clear() that allows passed-through PEs
to be excluded. Update callers to always pass true so that there is no
change in behaviour.
Also refactor to use direct traversal, to allow the removal of some
boilerplate.
This is to prepare for follow-up work for passed-through devices.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
eeh_unfreeze_pe() performs two operations: unfreezing a PE (which may
cause firmware to unfreeze child PEs as well) and de-isolating the PE
and it's children.
To simplify this and support future work, separate out the
de-isolation and perform it at the call sites (when necessary).
There should be no change in behaviour.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Including (in no particular order):
- Page table code for AMD IOMMU now supports large pages where
smaller page-sizes were mapped before. VFIO had to work around
that in the past and I included a patch to remove it (acked by
Alex Williamson)
- Patches to unmodularize a couple of IOMMU drivers that would
never work as modules anyway.
- Work to unify the the iommu-related pointers in
'struct device' into one pointer. This work is not finished
yet, but will probably be in the next cycle.
- NUMA aware allocation in iommu-dma code
- Support for r8a774a1 and r8a774c0 in the Renesas IOMMU driver
- Scalable mode support for the Intel VT-d driver
- PM runtime improvements for the ARM-SMMU driver
- Support for the QCOM-SMMUv2 IOMMU hardware from Qualcom
- Various smaller fixes and improvements
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Merge tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:
- Page table code for AMD IOMMU now supports large pages where smaller
page-sizes were mapped before. VFIO had to work around that in the
past and I included a patch to remove it (acked by Alex Williamson)
- Patches to unmodularize a couple of IOMMU drivers that would never
work as modules anyway.
- Work to unify the the iommu-related pointers in 'struct device' into
one pointer. This work is not finished yet, but will probably be in
the next cycle.
- NUMA aware allocation in iommu-dma code
- Support for r8a774a1 and r8a774c0 in the Renesas IOMMU driver
- Scalable mode support for the Intel VT-d driver
- PM runtime improvements for the ARM-SMMU driver
- Support for the QCOM-SMMUv2 IOMMU hardware from Qualcom
- Various smaller fixes and improvements
* tag 'iommu-updates-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (78 commits)
iommu: Check for iommu_ops == NULL in iommu_probe_device()
ACPI/IORT: Don't call iommu_ops->add_device directly
iommu/of: Don't call iommu_ops->add_device directly
iommu: Consolitate ->add/remove_device() calls
iommu/sysfs: Rename iommu_release_device()
dmaengine: sh: rcar-dmac: Use device_iommu_mapped()
xhci: Use device_iommu_mapped()
powerpc/iommu: Use device_iommu_mapped()
ACPI/IORT: Use device_iommu_mapped()
iommu/of: Use device_iommu_mapped()
driver core: Introduce device_iommu_mapped() function
iommu/tegra: Use helper functions to access dev->iommu_fwspec
iommu/qcom: Use helper functions to access dev->iommu_fwspec
iommu/of: Use helper functions to access dev->iommu_fwspec
iommu/mediatek: Use helper functions to access dev->iommu_fwspec
iommu/ipmmu-vmsa: Use helper functions to access dev->iommu_fwspec
iommu/dma: Use helper functions to access dev->iommu_fwspec
iommu/arm-smmu: Use helper functions to access dev->iommu_fwspec
ACPI/IORT: Use helper functions to access dev->iommu_fwspec
iommu: Introduce wrappers around dev->iommu_fwspec
...
Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files.
Semantic patch information:
Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file()
imposes some significant overhead as compared to
DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe().
Generated by: scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Use the new function to replace the open-coded iommu check.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell Currey <ruscur@russell.cc>
Cc: Sam Bobroff <sbobroff@linux.ibm.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
The wait_state member of eeh_ops does not need to be platform
dependent; it's just logic around eeh_ops.get_state(). Therefore,
merge the two (slightly different!) platform versions into a new
function, eeh_wait_state() and remove the eeh_ops member.
While doing this, also correct:
* The wait logic, so that it never waits longer than max_wait.
* The wait logic, so that it never waits less than
EEH_STATE_MIN_WAIT_TIME.
* One call site where the result is treated like a bit field before
it's checked for negative error values.
* In pseries_eeh_get_state(), rename the "state" parameter to "delay"
because that's what it is.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently, eeh_pe_state_mark() marks a PE (and it's children) with a
state and then performs additional processing if that state included
EEH_PE_ISOLATED.
The state parameter is always a constant at the call site, so
rearrange eeh_pe_state_mark() into two functions and just call the
appropriate one at each site.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The function eeh_pe_state_mark_with_cfg() just performs the work of
eeh_pe_state_mark() and then, conditionally, the work of
eeh_pe_state_clear(). However it is only ever called with a constant
state such that the condition is always true, so replace it by direct
calls.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently a flag, EEH_POSTPONED_PROBE, is used to prevent an incorrect
message "EEH: No capable adapters found" from being displayed during
the boot of powernv systems.
It is necessary because, on powernv, the call to eeh_probe_devices()
made from eeh_init() is too early and EEH can't yet be enabled. A
second call is made later from eeh_pnv_post_init(), which succeeds.
(On pseries, the first call succeeds because PCI devices are set up
early enough and no second call is made.)
This can be simplified by moving the early call to eeh_probe_devices()
from eeh_init() (where it's seen by both platforms) to
pSeries_final_fixup(), so that each platform only calls
eeh_probe_devices() once, at a point where it can succeed.
This is slightly later in the boot sequence, but but still early
enough and it is now in the same place in the sequence for both
platforms (the pcibios_fixup hook).
The display of the message can be cleaned up as well, by moving it
into eeh_probe_devices().
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
