To support CONFIG_VMAP_STACK, the kernel has to activate Data MMU
Translation for accessing the stack. Before doing that it must save
SRR0, SRR1 and also DAR and DSISR when relevant, in order to not
loose them in case there is a Data TLB Miss once the translation is
reactivated.

This patch adds fields in thread struct for saving those registers.
It prepares entry_32.S to handle exception entry with
Data MMU Translation enabled and alters EXCEPTION_PROLOG macros to
save SRR0, SRR1, DAR and DSISR then reenables Data MMU.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a775a1fea60f190e0f63503463fb775310a2009b.1576916812.git.christophe.leroy@c-s.fr

Refactor reading and saving of DAR and DSISR in exception vectors.

This will ease the implementation of VMAP stack.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1286b3e51b07727c6b4b05f2df9af3f9b1717fb5.1576916812.git.christophe.leroy@c-s.fr

In order to simplify  VMAP stack implementation, move
MSR_PR test into EXCEPTION_PROLOG_0.

This requires to not modify cr0 between EXCEPTION_PROLOG_0
and EXCEPTION_PROLOG_1.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5c8b5bba692b92654dbd363a229a1ba91db725bb.1576916812.git.christophe.leroy@c-s.fr

handle_page_fault() is the only function that save DAR/DEAR itself.

Save DAR/DEAR before calling handle_page_fault() to prepare for
VMAP stack which will require to save even before.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/3a4d58d378091086f00fde42b59610c80289e120.1576916812.git.christophe.leroy@c-s.fr

This patch creates a macro for the very first part of
exception prolog, this will help when implementing
CONFIG_VMAP_STACK
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2249fe62f481121a180e9655ad2b998093f318f3.1576916812.git.christophe.leroy@c-s.fr

On PPC32, MTMSRD() is simply defined as mtmsr.

Replace MTMSRD(reg) by mtmsr reg in files dedicated to PPC32,
this makes the code less obscure.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/22469e78230edea3dbd0c79a555d73124f6c6d93.1576916812.git.christophe.leroy@c-s.fr

Some newer cards supported by aacraid can take up to 40s to recover
after an EEH event. This causes spurious failures in the basic EEH
self-test since the current maximim timeout is only 30s.

Fix the immediate issue by bumping the timeout to a default of 60s,
and allow the wait time to be specified via an environmental variable
(EEH_MAX_WAIT).
Reported-by: NSteve Best <sbest@redhat.com>
Suggested-by: NDouglas Miller <dougmill@us.ibm.com>
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200122031125.25991-1-oohall@gmail.com

Correct overflow problem in calculation and display of Maximum Memory
value to syscfg.
Signed-off-by: NMichael Bringmann <mwb@linux.ibm.com>
[mpe: Only n_lmbs needs casting to unsigned long]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5577aef8-1d5a-ca95-ff0a-9c7b5977e5bf@linux.ibm.com

Commit a25bd72b ("powerpc/mm/radix: Workaround prefetch issue with
KVM") introduced a number of workarounds as coming out of a guest with
the mmu enabled would make the cpu would start running in hypervisor
state with the PID value from the guest. The cpu will then start
prefetching for the hypervisor with that PID value.

In Power9 DD2.2 the cpu behaviour was modified to fix this. When
accessing Quadrant 0 in hypervisor mode with LPID != 0 prefetching will
not be performed. This means that we can get rid of the workarounds for
Power9 DD2.2 and later revisions. Add a new cpu feature
CPU_FTR_P9_RADIX_PREFETCH_BUG to indicate if the workarounds are needed.
Signed-off-by: NJordan Niethe <jniethe5@gmail.com>
Acked-by: NPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191206031722.25781-1-jniethe5@gmail.com

String 'bus_desc.provider_name' allocated inside
papr_scm_nvdimm_init() will leaks in case call to
nvdimm_bus_register() fails or when papr_scm_remove() is called.

This minor patch ensures that 'bus_desc.provider_name' is freed in
error path for nvdimm_bus_register() as well as in papr_scm_remove().

Fixes: b5beae5e ("powerpc/pseries: Add driver for PAPR SCM regions")
Signed-off-by: NVaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200122155140.120429-1-vaibhav@linux.ibm.com

Fix couple of compile errors I stumbled upon with CONFIG_XMON=y and
CONFIG_XMON_DISASSEMBLY=n
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200123010455.GA15080@us.ibm.com

Instead of opencoding, use probe_user_read() to failessly read
a user location and probe_user_write() for writing to user.
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e041f5eedb23f09ab553be8a91c3de2087147320.1579800517.git.christophe.leroy@c-s.fr

Fixes coccicheck warning:
  arch/powerpc/platforms/maple/setup.c:232:15-16:
	WARNING comparing pointer to 0

Compare pointer-typed values to NULL rather than 0.
Signed-off-by: NChen Zhou <chenzhou10@huawei.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200121013153.9937-1-chenzhou10@huawei.com

Commit e5afdf9d ("powerpc/vfio_spapr_tce: Add reference counting to
iommu_table") missed an iommu_table allocation in the pseries vio code.
The iommu_table is allocated with kzalloc and as a result the associated
kref gets a value of zero. This has the side effect that during a DLPAR
remove of the associated virtual IOA the iommu_tce_table_put() triggers
a use-after-free underflow warning.

Call Trace:
[c0000002879e39f0] [c00000000071ecb4] refcount_warn_saturate+0x184/0x190
(unreliable)
[c0000002879e3a50] [c0000000000500ac] iommu_tce_table_put+0x9c/0xb0
[c0000002879e3a70] [c0000000000f54e4] vio_dev_release+0x34/0x70
[c0000002879e3aa0] [c00000000087cfa4] device_release+0x54/0xf0
[c0000002879e3b10] [c000000000d64c84] kobject_cleanup+0xa4/0x240
[c0000002879e3b90] [c00000000087d358] put_device+0x28/0x40
[c0000002879e3bb0] [c0000000007a328c] dlpar_remove_slot+0x15c/0x250
[c0000002879e3c50] [c0000000007a348c] remove_slot_store+0xac/0xf0
[c0000002879e3cd0] [c000000000d64220] kobj_attr_store+0x30/0x60
[c0000002879e3cf0] [c0000000004ff13c] sysfs_kf_write+0x6c/0xa0
[c0000002879e3d10] [c0000000004fde4c] kernfs_fop_write+0x18c/0x260
[c0000002879e3d60] [c000000000410f3c] __vfs_write+0x3c/0x70
[c0000002879e3d80] [c000000000415408] vfs_write+0xc8/0x250
[c0000002879e3dd0] [c0000000004157dc] ksys_write+0x7c/0x120
[c0000002879e3e20] [c00000000000b278] system_call+0x5c/0x68

Further, since the refcount was always zero the iommu_tce_table_put()
fails to call the iommu_table release function resulting in a leak.

Fix this issue be initilizing the iommu_table kref immediately after
allocation.

Fixes: e5afdf9d ("powerpc/vfio_spapr_tce: Add reference counting to iommu_table")
Signed-off-by: NTyrel Datwyler <tyreld@linux.ibm.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1579558202-26052-1-git-send-email-tyreld@linux.ibm.com

Setting ND_REGION_PAGEMAP flag implies namespace mode defaults to fsdax mode.
This also means kernel ends up creating struct page backing for these namspace
ranges. With large namespaces that is not the right thing to do. We
should let the user select the mode he/she wants the namespace to be created
with.

Hence disable ND_REGION_PAGEMAP for papr_scm regions. We still keep the flag for
of_pmem because it supports only small persistent memory regions.

This is similar to what is done for x86 with commit
commit: 004f1afb ("libnvdimm, pmem: direct map legacy pmem by default")
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200108064647.169637-1-aneesh.kumar@linux.ibm.com

As reported by ./scripts/checkpatch.pl --strict:

CHECK: extern prototypes should be avoided in .h files
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/157384145834.181768.944827793193636924.stgit@bahia.lan

Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156219139988.578018.1046848908285019838.stgit@bahia.lan

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
	$ sed -e 's/^        /\t/' -i */Kconfig
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191120134115.14918-1-krzk@kernel.org

Michael Ellerman made a call for volunteers from NXP to maintain
this driver and I offered myself.
Signed-off-by: NLaurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: NTimur Tabi <timur@kernel.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200114110012.17351-1-laurentiu.tudor@nxp.com

This is only used in pci-ioda.c so move it there and rename it to match.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-6-oohall@gmail.com

pnv_pci_dma_dev_setup() does nothing but call the phb->dma_dev_setup()
callback, if one exists. That callback is only set for normal PCIe PHBs so
we can remove the layer of indirection and use the ioda version in
the pci_controller_ops.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-5-oohall@gmail.com

An ioda_pe for each VF is allocated in pnv_pci_sriov_enable() before
the pci_dev for the VF is created. We need to set the pe->pdev pointer
at some point after the pci_dev is created. Currently we do that in:

pcibios_bus_add_device()
	pnv_pci_dma_dev_setup() (via phb->ops.dma_dev_setup)
		/* fixup is done here */
		pnv_pci_ioda_dma_dev_setup() (via pnv_phb->dma_dev_setup)

The fixup needs to be done before setting up DMA for for the VF's PE,
but there's no real reason to delay it until this point. Move the
fixup into pnv_pci_ioda_fixup_iov() so the ordering is:

	pcibios_add_device()
		pnv_pci_ioda_fixup_iov() (via ppc_md.pcibios_fixup_sriov)

	pcibios_bus_add_device()
		...

This isn't strictly required, but it's a slightly more logical place
to do the fixup and it simplifies pnv_pci_dma_dev_setup().
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-4-oohall@gmail.com

The pnv_pci_dma_dev_setup() only does something when:

1) There PHB contains VFs, or
2) The PHB defines a dma_dev_setup() callback in the pnv_phb structure.

Neither is true for NPU PHBs so there's no reason to set the callback.
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-3-oohall@gmail.com

pcibios_bus_add_device() is the only caller of pcibios_setup_device().
Fold them together since there's no real reason to keep them separate.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200110070207.439-2-oohall@gmail.com

OPAL provides several different kinds of reboot for the kernel to use,
namely forcing a full reboot, platform error reboot and MPIPL. Right now
triggering the alternative resets requires some ad-hoc method such as
triggering a kernel crash and hoping the stars align. It's sometimes handy
to be able to trigger one of these resets directly, so add a way to do
that.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101085522.3055-2-oohall@gmail.com

On PowerNV a few different kinds of reboot are supported. We'd like to be
able to exercise these from xmon so allow 'zr' to take an argument, and
pass that to the ppc_md.restart() function.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101085522.3055-1-oohall@gmail.com

Long before we had a generic way for firmware to export memory ranges of
interest we added a special case for the skiboot symbol map. The code is
pretty much identical to the generic export so re-use the code.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101062611.32610-2-oohall@gmail.com

Originally we only had a handful of exported memory ranges, but we'd to
export the per-core trace buffers. This results in a lot of files in the
exports directory which is a but unfortunate. We can clean things up a bit
by turning subnodes into subdirectories of the exports directory.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191101062611.32610-1-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: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Tested-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191016012536.22588-1-oohall@gmail.com

Add a debugfs entry to dump the state of the active IODA PEs. The IODA
PE state reflects how the PHB's internal concept of a PE is
configured. This is separate to the EEH PE state and is managed power
the PowerNV PCI backend rather than the EEH core.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
[mpe: Use DEFINE_DEBUGFS_ATTRIBUTE]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912052945.12589-3-oohall@gmail.com

Make the dump trigger off any input rather than just '1'. This allows you
to write "echo 1> dump_diag_data" and it'll do what you want rather than
erroring out pointlessly.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912052945.12589-2-oohall@gmail.com

Use the pnv_phb structure as the private data pointer for the debugfs
files.  This lets us delete some code and an open-coded use of
hose->private_data.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190912052945.12589-1-oohall@gmail.com

These functions can only be used on a SR-IOV capable physical function and
they're only called in pcibios_sriov_enable / disable. Make them emit a
warning in the future if they're used incorrectly and remove the dead
code that checks if the device is a VF.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-3-oohall@gmail.com

The powerpc PCI code requires that a pci_dn structure exists for all
devices in the system. This is fine for real devices since at boot a pci_dn
is created for each PCI device in the DT and it's fine for hotplugged devices
since the hotplug slot driver will manage the pci_dn's devices in hotplug
slots. For SR-IOV, we need the platform / pcibios to manage the pci_dn for
virtual functions since firmware is unaware of VFs, and they aren't
"hot plugged" in the traditional sense.

Management of the pci_dn is handled by the, poorly named, functions:
add_pci_dev_data() and remove_pci_dev_data(). The entire body of these
functions is #ifdef`ed around CONFIG_PCI_IOV and they cannot be used
in any other context, so make them only available when CONFIG_PCI_IOV
is selected, and rename them to reflect their actual usage rather than
having them masquerade as generic code.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-2-oohall@gmail.com

When disabling virtual functions on an SR-IOV adapter we currently do not
correctly remove the EEH state for the now-dead virtual functions. When
removing the pci_dn that was created for the VF when SR-IOV was enabled
we free the corresponding eeh_dev without removing it from the child device
list of the eeh_pe that contained it. This can result in crashes due to the
use-after-free.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Tested-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190821062655.19735-1-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: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Tested-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-6-oohall@gmail.com

In eeh_notify_resume_show() the pci_dn for the device is looked up once in
the declaration block and then once after checking for a NULL eeh_dev.
Remove the second lookup since it's pointless.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Tested-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-5-oohall@gmail.com

There are several EEH sysfs properties that only exists when the
"ibm,is-open-sriov-pf" property appears in the device tree node of the PCI
device. This used on pseries to indicate to the guest that the hypervisor
allows the guest to configure the SR-IOV capability. Doing this requires
some handshaking between the guest, hypervisor and userspace when a VF is
EEH frozen which is why these properties exist.

This is all dead code on non-pseries platforms so wrap it in an #ifdef
CONFIG_PPC_PSERIES to make the dependency clearer.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Tested-by: NSam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-4-oohall@gmail.com

The EEH_ATTR_SHOW() helper is used to display fields from struct eeh_dev
not struct pci_dn.
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-3-oohall@gmail.com

At the point where we start inserting ranges into the EEH address cache the
binding between pci_dev and eeh_dev has already been set up. Instead of
consulting the pci_dn tree we can retrieve the eeh_dev directly using
pci_dev_to_eeh_dev().
Signed-off-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NSam Bobroff <sbobroff@linux.ibm.com>
Tested-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190715085612.8802-2-oohall@gmail.com