This code is no longer used and can be removed.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the powerpc boot wrapper has its own wrapper around zlib to
handle decompressing gzipped kernels. The kernel decompressor library
functions now provide a generic interface that can be used in the
pre-boot environment. This allows boot wrappers to easily support
different compression algorithms. This patch converts the wrapper to use
this new API, but does not add support for using new algorithms.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Most architectures allow the compression algorithm used to produced the
vmlinuz image to be selected as a kernel config option. In preperation
for supporting algorithms other than gzip in the powerpc boot wrapper
the makefile needs to be modified to use these config options.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The powerpc boot wrapper is potentially compiled with a separate
toolchain and/or toolchain flags than the rest of the kernel. The usual
case is a 64-bit big endian kernel builds a 32-bit big endian wrapper.
The main problem with this is that the wrapper does not have access to
the kernel headers (without a lot of gross hacks). To get around this
the required headers are copied into the build directory via several sed
scripts which rewrite problematic includes. This patch moves these
fixups out of the makefile into a separate .sed script file to clean up
makefile slightly.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Reword first paragraph of change log a little]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It might be nice to compile selftests against older kernels and
headers but which may not have HWCAP2.
Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The same logic appears twice and should probably be pulled out into a
function.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Rui Teng <rui.teng@linux.vnet.ibm.com>
[mpe: Rename to tm_flush_hash_page() and move comment into the function]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
CLR_TOP32() is defined as blank. Last useful instance of CLR_TOP32()
was removed by commit 40ef8cbc6d ("powerpc: Get 64-bit configs to
compile with ARCH=powerpc") in 2005.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On some CPUs like the 8xx, _PAGE_RW hence _PAGE_WRITE is defined
as 0 and _PAGE_RO has to be set when a page is not writable
_PAGE_RO is defined by default in pte-common.h, however BOOK3S/64
doesn't include that file so _PAGE_RO has to be defined explicitly
in book3s/64/pgtable.h
Fixes: a7b9f671f2 ("powerpc32: adds handling of _PAGE_RO")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In eeh_handle_special_event(), eeh_pe_bus_get() is called before calling
eeh_report_failure() on every device under a PE. If a PE was missing a
bus for some reason, the error would occur before reporting failure, even
though eeh_report_failure() doesn't require a bus.
Fix this by moving the bus retrieval and error check after the
eeh_report_failure() calls.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When the PE used in pnv_eeh_reset() is that of a VF,
pnv_eeh_reset_vf_pe() is used. Unlike the other reset functions called
in pnv_eeh_reset(), the VF reset doesn't require a bus, and if a bus was
missing the function would error out before resetting the VF PE.
To avoid this, reorder the VF reset function to occur before finding and
checking the bus.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
eeh_pe_bus_get() can return NULL if a PCI bus isn't found for a given PE.
Some callers don't check this, and can cause a null pointer dereference
under certain circumstances.
Fix this by checking NULL everywhere eeh_pe_bus_get() is called.
Fixes: 8a6b1bc70d ("powerpc/eeh: EEH core to handle special event")
Cc: stable@vger.kernel.org # v3.11+
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we originally added the ability to split the exception vectors from
the kernel (commit 1f6a93e4c3 ("powerpc: Make it possible to move the
interrupt handlers away from the kernel" 2008-09-15)), the LOAD_HANDLER() macro
used an addi instruction to compute the offset of the common handler
from the kernel base address.
Using addi meant the handler had to be within 32K of the kernel base
address, due to the addi instruction taking a signed immediate value.
That necessitated creating a trampoline for the system call handler,
because system_call_common (in entry64.S) is not linked within 32K of
the kernel base address.
Later in commit 61e2390ede ("powerpc: Make load_hander handle upto 64k
offset" 2012-11-15) we changed LOAD_HANDLER to take a 64K offset, by
changing it to use ori.
Although system_call_common is not in head_64.S or exceptions-64s.S, it
is included in head-y, which causes it to be linked early in the kernel
text, so in practice it ends up below 64K. Additionally if it can't be
placed below 64K the linker will fail to build with a "relocation
truncated to fit" error.
So remove the trampoline.
Newer toolchains are able to work out that the ori in LOAD_HANDLER only
takes a 16 bit offset, and so they generate a 16 bit relocation. Older
toolchains (binutils 2.22 at least) are not so smart, so we have to add
the @l annotation to tell the assembler to generate a 16 bit relocation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The 0xf80 hv_facility_unavailable trampoline branches to the 0xf60
handler. This works because they both do the same thing, but it should
be fixed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On EEH events the kernel will print a dump of relevant registers.
If EEH is unavailable (i.e. CONFIG_EEH is disabled, a new platform
doesn't have EEH support, etc) this information isn't readily available.
Add a new debugfs handler to trigger a PHB register dump, so that this
information can be made available on demand.
Signed-off-by: Russell Currey <ruscur@russell.cc>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The only difference is now the TCE table check which doesn't need
to be ifdef'ed out, it will basically do nothing on BookE (it is
only useful for ancient IBM machines).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we turn the MMU off after copying the image, and we make
sure there is no overlap between the hash table and the target pages
in that case.
That doesn't work for Radix however. In that case, the page tables
are scattered and we can't really enforce that the target of the
image isn't overlapping one of them.
So instead, let's turn the MMU off before copying the image in radix
mode. Thankfully, in radix mode, even under a hypervisor, we know we
don't have the same kind of RMA limitations that hash mode has.
While at it, also turn the MMU off early when using hash in non-LPAR
mode, that way we can get rid of the collision check completely.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Just using the hash ops won't work anymore since radix will have
NULL in there. Instead create an mmu_cleanup_all() function which
will do the right thing based on the MMU mode.
For Radix, for now I clear UPRT and the PTCR, effectively switching
back to Radix with no partition table setup.
Currently set it to NULL on BookE thought it might be a good idea
to wipe the TLB there (Scott ?)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
With Radix, it can be NULL even on !BOOKE these days so replace
the ifdef with a NULL check which is cleaner anyway.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
NO_IRQ has been == 0 on powerpc for just over ten years (since commit
0ebfff1491 ("[POWERPC] Add new interrupt mapping core and change
platforms to use it")). It's also 0 on most other arches.
Although it's fairly harmless, every now and then it causes confusion
when a driver is built on powerpc and another arch which doesn't define
NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least
some of which are to work around that problem.
So we'd like to remove it. This is fairly trivial in the arch code, we
just convert:
if (irq == NO_IRQ) to if (!irq)
if (irq != NO_IRQ) to if (irq)
irq = NO_IRQ; to irq = 0;
return NO_IRQ; to return 0;
And a few other odd cases as well.
At least for now we keep the #define NO_IRQ, because there is driver
code that uses NO_IRQ and the fixes to remove those will go via other
trees.
Note we also change some occurrences in PPC sound drivers, drivers/ps3,
and drivers/macintosh.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Fred has taken over the cxl maintenance I was doing. This updates the
MAINTAINERS file to reflect this.
It also removes a duplicate entry in the files covered and adds an entry
for the CXL PCI code in arch/powerpc.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If we fail to allocate work, we don't end up using hp_errlog_copy. Free it
in the error path.
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When we merge two contiguous partitions whose signatures are marked
NVRAM_SIG_FREE, We need update prev's length and checksum, then write it
to nvram, not cur's. So lets fix this mistake now.
Also use memset instead of strncpy to set the partition's name. It's
more readable if we want to fill up with duplicate chars .
Fixes: fa2b4e54d4 ("powerpc/nvram: Improve partition removal")
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If kmemdup fails, We need kfree *buff* first then return -ENOMEM.
Otherwise there is a memory leak.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
mtmsrd with L=1 only affects MSR_EE and MSR_RI bits, and we always
know what state those bits are, so the kernel MSR does not need to be
loaded when modifying them.
mtmsrd is often in the critical execution path, so avoiding dependency
on even L1 load is noticable. On a POWER8 this saves about 3 cycles
from the syscall path, and possibly a few from other exception returns
(not measured).
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The mflr r10 instruction was left over from when the code used LR to
branch to system_call_entry from the exception handler. That was
changed by commit 6a404806df ("powerpc: Avoid link stack corruption in
MMU on syscall entry path") to use the count register. The value is
never used now, so mflr can be removed, and r10 can be used for storage
rather than spilling to the SPR scratch register.
The scratch register spill causes a long pipeline stall due to the SPR
read after write. This change brings getppid syscall cost from 406 to
376 cycles on POWER8. getppid for non-relocatable case is 371 cycles.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
For hugetlb to work with 4K page size, we need MAX_ORDER to be 13 or
more. When switching from a 64K page size to 4K linux page size using
make oldconfig, we end up with a CONFIG_FORCE_MAX_ZONEORDER value of 9.
This results in a 16M hugepage beiing considered as a gigantic huge page
which in turn results in failure to setup hugepages if gigantic hugepage
support is not enabled.
This also results in kernel crash with 4K radix configuration. We
hit the below BUG_ON on radix:
kernel BUG at mm/huge_memory.c:364!
Oops: Exception in kernel mode, sig: 5 [#1]
SMP NR_CPUS=2048 NUMA PowerNV
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc1-00006-gbae9cc6 #1
task: c0000000f1af8000 task.stack: c0000000f1aec000
NIP: c000000000c5fa0c LR: c000000000c5f9d8 CTR: c000000000c5f9a4
REGS: c0000000f1aef920 TRAP: 0700 Not tainted (4.8.0-rc1-00006-gbae9cc6)
MSR: 9000000102029033 <SF,HV,VEC,EE,ME,IR,DR,RI,LE,TM[E]> CR: 24000844 XER: 00000000
CFAR: c000000000c5f9e0 SOFTE: 1
....
NIP [c000000000c5fa0c] hugepage_init+0x68/0x238
LR [c000000000c5f9d8] hugepage_init+0x34/0x238
Fixes: a7ee539584 ("powerpc/Kconfig: Update config option based on page size")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: Santhosh <santhog4@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add some documentation for the 64-bit syscall ABI, which doesn't seem
to be documented elsewhere.
This attempts to document existing practice. The only small discrepancy
is glibc clobbers not quite matching the kernel (e.g., xer, some
vsyscalls trash cr1 whereas glibc only clobbers cr0). These will be
resolved after this document is merged.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The HMI (Hypervisor Maintenance Interrupt) is defined by the
architecture to be higher priority than other maskable interrupts, so
replay it first, as a best-effort to replay according to hardware
priorities.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
In our linker script we open code the list of text sections, because we
need to include the __ftr_alt sections, which are arch-specific.
This means we can't use TEXT_TEXT as defined in vmlinux.lds.h, and so we
don't have the MEM_KEEP() logic for memory hotplug sections.
If we build the kernel with the gold linker, and with CONFIG_MEMORY_HOTPLUG=y,
we see that functions marked __meminit can end up outside of the
_stext/_etext range, and also outside of _sinittext/_einittext, eg:
c000000000000000 T _stext
c0000000009e0000 A _etext
c0000000009e3f18 T hash__vmemmap_create_mapping
c000000000ca0000 T _sinittext
c000000000d00844 T _einittext
This causes them to not be recognised as text by is_kernel_text(), and
prevents them being patched by jump_label (and presumably ftrace/kprobes
etc.).
Fix it by adding MEM_KEEP() directives, mirroring what TEXT_TEXT does.
This isn't a problem when CONFIG_MEMORY_HOTPLUG=n, because we use the
standard INIT_TEXT_SECTION() and EXIT_TEXT macros from vmlinux.lds.h.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently the _GLOBAL() macro unilaterally sets the assembler section to
".text" at the start of the macro. This is rude as the caller may be
using a different section.
So let the caller decide which section to emit the code into. On big
endian we do need to switch to the ".opd" section to emit the OPD, but
do that with pushsection/popsection, thereby leaving the original
section intact.
I verified that the order of all entries in System.map is unchanged
after this patch. The actual addresses shift around slightly so you
can't just diff the System.map.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Rather than forcing the whole function into the ".kprobes.text" section,
just add the symbol's address to the kprobe blacklist.
This also lets us drop the three versions of the_KPROBE macro, in
exchange for just one version of _ASM_NOKPROBE_SYMBOL - which is a good
cleanup.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Currently we mark the C implementations of some exception handlers as
__kprobes. This has the effect of putting them in the ".kprobes.text"
section, which separates them from the rest of the text.
Instead we can use the blacklist macros to add the symbols to a
blacklist which kprobes will check. This allows the linker to move
exception handler functions close to callers and avoids trampolines in
larger kernels.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Reword change log a bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Normally, when MSR[VSX/VR/SPE] bits == 1, the used_vsr/used_vr/used_spe
bit have already been set. However when loading a signal frame from user
space we need to explicitly set used_vsr/used_vr/used_spe to make them
consistent with the MSR bits from the signal frame.
For example, CRIU application, who utilizes sigreturn to restore
checkpointed process, will lead to the case where MSR[VSX] bit is active
in signal frame, but used_vsr bit is not set in the kernel. (the same
applies to VR/SPE).
This patch fixes this by always setting used_* bit when MSR related bits
are active in signal frame and we are doing sigreturn.
Based on a proposal by Benh.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
[mpe: Massage change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The ckpt_regs usage in gpr32_set_common/gpr32_get_common() will lead to
following cppcheck error at ifndef CONFIG_PPC_TRANSACTIONAL_MEM case:
[arch/powerpc/kernel/ptrace.c:2062]:
(error) Uninitialized variable: ckpt_regs
[arch/powerpc/kernel/ptrace.c:2130]:
(error) Uninitialized variable: ckpt_regs
The problem is due to gpr32_set_common() used ckpt_regs variable which
only makes sense at #ifdef CONFIG_PPC_TRANSACTIONAL_MEM.
This patch fix this issue by passing in "regs" parameter instead.
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Simon Guo <wei.guo.simon@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When set_sl_ops() is called, the adapter data structure is not fully
initialized yet. Therefore the device name is not showing up in the
trace. Fix is simply to get the device name from the pci_dev
structure.
Fixes: 6d382616ac ("cxl: Abstract the differences between the PSL and XSL")
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The message is missing a \n, add it. Switch to pr_warn(), it's shorter
and less ugly.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Power9 DD1 requires to update the hid0 register when switching from
hash to radix.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD1 requires pte to be marked invalid (V=0) before updating
it with the new value. This makes this distinction for the different
revisions.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
POWER9 DD1 uses RTS - 28 for the RTS value but other revisions use
RTS - 31. This makes this distinction for the different revisions
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The of_node for the SB600 (io-bridge) has its device_type set to
'io-bridge' Set it to 'isa' so that it can be found by
isa_bridge_find_early() instead of using patches in the kernel.
Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The device tree on the Nemo passes all of the i8259 interrupts with
numbers between 212 and 222, and points their interrupt-parent property
to the pasemi-opic, requiring custom patches to the kernel. Fix the
values so that they can be controlled by the generic ppc i8259 code.
Signed-off-by: Darren Stevens <darren@stevens-zone.net>
[mpe: Rework deeply nested if and boundary checks]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add config option for the Nemo motherboard used in the Amigaone X1000.
This is a custom PASemi board with an AMD SB600 southbridge, and needs
some patches to it device tree. This option will be used to build these
into the kernel
Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Checkpatch.pl warns about usage of asm/io.h. Use linux/io.h instead.
Signed-off-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Trivial fix to spelling mistake in dev_warn message and remove
extraneous trailing whitespace at end of the message.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit 2578bfae84 ("[POWERPC] Create and use CONFIG_WORD_SIZE") added
CONFIG_WORD_SIZE, and suggests that other arches were going to do
likewise.
But that never happened, powerpc is the only architecture which uses it.
So switch to using a simple make variable, BITS, like x86, sh, sparc and
tile. It is also easier to spell and simpler, avoiding any confusion
about whether it's defined due to ordering of make vs kconfig.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Some of the rules in the boot Makefile use @ to hide the command, this
means "make V=1" doesn't show them, which is confusing.
So use the Kbuild standard $(Q) which means KBUILD_VERBOSE=1 or V=1 will
work as expected.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Oliver O'Halloran