As part of commits a64aa578 "hw: Deprecate -drive if=scsi with non-onboard
HBAs" and b891538e "hw/ppc/prep: Fix implicit creation of "-drive if=scsi"
devices" the lsi53c895a_create() and lsi53c810_create() functions were added
to wrap pci_create_simple() and scsi_bus_legacy_handle_cmdline().

Unfortunately this prevents us from changing qdev properties on the device
and/or changing the PCI configuration. By switching over to using the new
lsi53c8xx_handle_legacy_cmdline() function then the caller can now configure
and realize the LSI SCSI device exactly as required.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Peter Maydell <peter.maydell@linaro.org> [arm parts]
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

So that we don't have to call qdev_get_machine() to get the machine
class and the sPAPRIrq backend holding the number of MSIs.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

The new layout using static IRQ number does not leave much space to
the dynamic MSI range, only 0x100 IRQ numbers. Increase the total
number of IRQS for newer machines and introduce a legacy XICS backend
for pre-3.1 machines to maintain compatibility.

For the old backend, provide a 'nr_msis' value covering the full IRQ
number space as it does not use the bitmap allocator to allocate MSI
interrupt numbers.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

The number of MSI interrupts a sPAPR machine can allocate is in direct
relation with the number of interrupts of the sPAPRIrq backend. Define
statically this value at the sPAPRIrq class level and use it for the
"ibm,pe-total-#msi" property of the sPAPR PHB.

According to the PAPR specs, "ibm,pe-total-#msi" defines the maximum
number of MSIs that are available to the PE. We choose to advertise
the maximum number of MSIs that are available to the machine for
simplicity of the model and to avoid segmenting the MSI interrupt pool
which can be easily shared. If the pool limit is reached, it can be
extended dynamically.

Finally, remove XICS_IRQS_SPAPR which is now unused.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

According to the PReP specification section 6.1.6 "System Interrupt
Assignments", all PCI interrupts are routed via IRQ 15.

Instead of mapping each PCI IRQ separately, we introduce an OR gate within the
raven PCI host bridge and then wire the single output of the OR gate to the
interrupt controller.

Note that whilst the (now deprecated) PReP machine still exists we still need
to preserve the old IRQ routing. This is done by adding a new "is-legacy-prep"
property to the raven PCI host bridge which is set to true for the PReP
machine.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NHervé Poussineau <hpoussin@reactos.org>
Tested-by: NHervé Poussineau <hpoussin@reactos.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

OpenBIOS gained 40p support in 5b20e4ca
Use it, instead of relying on an unmaintained and very limited firmware.
Signed-off-by: NHervé Poussineau <hpoussin@reactos.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Set the newly added register(KVM_REG_PPC_ONLINE) to indicate if the vcpu is
online(1) or offline(0)

KVM will use this information to set the RWMR register, which controls the PURR
and SPURR accumulation.

CC: paulus@samba.org
Signed-off-by: NNikunj A Dadhania <nikunj@linux.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

We need to set cs->halted to 1 before calling ppc_set_compat. The reason
is that ppc_set_compat kicks up the new thread created to manage the
hotplugged KVM virtual CPU and the code drives directly to KVM_RUN
ioctl. When cs->halted is 1, the code:

int kvm_cpu_exec(CPUState *cpu)
...
     if (kvm_arch_process_async_events(cpu)) {
         atomic_set(&cpu->exit_request, 0);
         return EXCP_HLT;
     }
...

returns before it reaches KVM_RUN, giving time to the main thread to
finish its job. Otherwise we can fall in a deadlock because the KVM
thread will issue the KVM_RUN ioctl while the main thread is setting up
KVM registers. Depending on how these jobs are scheduled we'll end up
freezing QEMU.

The following output shows kvm_vcpu_ioctl sleeping because it cannot get
the mutex and never will.
PS: kvm_vcpu_ioctl was triggered kvm_set_one_reg - compat_pvr.

STATE: TASK_UNINTERRUPTIBLE|TASK_WAKEKILL

PID: 61564  TASK: c000003e981e0780  CPU: 48  COMMAND: "qemu-system-ppc"
 #0 [c000003e982679a0] __schedule at c000000000b10a44
 #1 [c000003e98267a60] schedule at c000000000b113a8
 #2 [c000003e98267a90] schedule_preempt_disabled at c000000000b11910
 #3 [c000003e98267ab0] __mutex_lock at c000000000b132ec
 #4 [c000003e98267bc0] kvm_vcpu_ioctl at c00800000ea03140 [kvm]
 #5 [c000003e98267d20] do_vfs_ioctl at c000000000407d30
 #6 [c000003e98267dc0] ksys_ioctl at c000000000408674
 #7 [c000003e98267e10] sys_ioctl at c0000000004086f8
 #8 [c000003e98267e30] system_call at c00000000000b488

crash> struct -x kvm.vcpus 0xc000003da0000000
vcpus = {0xc000003db4880000, 0xc000003d52b80000, 0xc0000039e9c80000, 0xc000003d0e200000, 0xc000003d58280000, 0x0, 0x0, ...}

crash> struct -x kvm_vcpu.mutex.owner 0xc000003d58280000
  mutex.owner = {
    counter = 0xc000003a23a5c881 <- flag 1: waiters
  },

crash> bt 0xc000003a23a5c880
PID: 61579  TASK: c000003a23a5c880  CPU: 9   COMMAND: "CPU 4/KVM"
(active)

crash> struct -x kvm_vcpu.mutex.wait_list 0xc000003d58280000
  mutex.wait_list = {
    next = 0xc000003e98267b10,
    prev = 0xc000003e98267b10
  },

crash> struct -x mutex_waiter.task 0xc000003e98267b10
  task = 0xc000003e981e0780

The following command-line was used to reproduce the problem (note: gdb
and trace can change the results).

 $ qemu-ppc/build/ppc64-softmmu/qemu-system-ppc64 -cpu host \
     -enable-kvm -m 4096 \
     -smp 4,maxcpus=8,sockets=1,cores=2,threads=4 \
     -display none -nographic \
     -drive file=disk1.qcow2,format=qcow2
 ...
 (qemu) device_add host-spapr-cpu-core,core-id=4
[no interaction is possible after it, only SIGKILL to take the terminal
back]
Signed-off-by: NJose Ricardo Ziviani <joserz@linux.ibm.com>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

spapr_init_cpus() currently creates spapr-cpu-core objects via
object_new() and setting their realized property to true. This leaves
their reference count at two, because object_new() adds an initial
reference and the realization attaches them to a default parent object
which also increments the reference count.

This causes a problem if one of these cores is hot unplugged: no
delete event is generated for it because it's reference count doesn't
reach zero when it is detached from it's parent.

Correct this by adding a call to object_unref() in spapr_init_cpus().
Signed-off-by: NSam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

This enables the correct generation of bootdevice fw paths for in-built IDE
and virtio-pci-blk devices suitable for OpenBIOS.

Note we also set the MachineClass ignore_boot_device_suffixes property to true
since an additional disk node should not be added except for virtio devices.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

This enables the correct generation of bootdevice fw paths for in-built IDE
and virtio-pci-blk devices suitable for OpenBIOS.

Note we also set the MachineClass ignore_boot_device_suffixes property to true
since an additional disk node should not be added except for virtio devices.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

The generated qapi_event_send_FOO() take an Error ** argument.  They
can't actually fail, because all they do with the argument is passing it
to functions that can't fail: the QObject output visitor, and the
@qmp_emit callback, which is either monitor_qapi_event_queue() or
event_test_emit().

Drop the argument, and pass &error_abort to the QObject output visitor
and @qmp_emit instead.
Suggested-by: NEric Blake <eblake@redhat.com>
Suggested-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <20180815133747.25032-4-peterx@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
[Commit message rewritten, update to qapi-code-gen.txt corrected]
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

Commit 2c88b098 added a call to SPAPR_MACHINE_GET_CLASS(spapr) in
spapr_phb_realize() before we check spapr isn't NULL. This causes QEMU
to crash when starting a non-pseries machine with a sPAPR PHB.

This could be fixed by setting the smc variable after the null check,
but it seems more explicit to use a ternary operator to skip the call
to SPAPR_MACHINE_GET_CLASS() if spapr is NULL, since spapr_phb_realize()
will return immediately in this case.

This was reported by Coverity (CID 1395170 and 1395183).

Fixes: 2c88b098Signed-off-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Introduced in 04d595b3 ("spapr: do not use CPU_FOREACH_REVERSE",
2018-08-23)

Fixes: CID1395181
Reported-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NEmilio G. Cota <cota@braap.org>
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

There is no known available OS for ppc around anymore that uses page
sizes below 4k, so it does not make much sense that we keep wasting
our time on building and testing the ppcemb-softmmu target. It has
been deprecated since two releases, and nobody complained, so let's
remove this now.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

We can assign and verify the address before realizing and trying to plug.
reading/writing the address property should never fail for DIMMs, so let's
reduce error handling a bit by using &error_abort. Getting access to the
memory region now might however fail. So forward errors from
get_memory_region() properly.

As all memory devices should use the alignment of the underlying memory
region for guest physical address asignment, do detection of the
alignment in pc_dimm_pre_plug(), but allow pc.c to overwrite the
alignment for compatibility handling.
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Acked-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20180801133444.11269-5-david@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We can assign and verify the slot before realizing and trying to plug.
reading/writing the slot property should never fail, so let's reduce
error handling a bit by using &error_abort.

To do this during pre_plug, add and use (x86, ppc) pc_dimm_pre_plug().
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Message-Id: <20180801133444.11269-2-david@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This paves the way for implementing the CPU list with an RCU list,
which cannot be traversed in reverse order.

Note that this is the only caller of CPU_FOREACH_REVERSE.
Acked-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NEmilio G. Cota <cota@braap.org>
Message-Id: <20180819091335.22863-11-cota@braap.org>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There is currently a funny problem with the "mc146818rtc" device:
1) Start QEMU like this:
   qemu-system-ppc64 -M pseries -S
2) At the HMP monitor, enter "info qom-tree". Note that there is an
   entry for "/rtc (spapr-rtc)".
3) Introspect the mc146818rtc device like this:
   device_add mc146818rtc,help
4) Run "info qom-tree" again. The "/rtc" entry is gone now!

The rtc_finalize() function of the mc146818rtc device has two bugs: First,
it tries to remove a "rtc" property, while the rtc_realizefn() added a
"rtc-time" property instead. And second, it should have been done in an
unrealize function, not in a finalize function, to avoid that this causes
problems during introspection.

But since adding aliases to the global machine state should not be done
from a device's realize function anyway, let's rather fix this issue
by moving the creation of the alias to the code that creates the device
(and thus is run from the machine init functions instead), i.e. the
mc146818_rtc_init() function for most machines. The prep machines are
special, since the mc146818rtc device is created here in the realize
function of the i82378 device. Since we certainly don't want to add the
alias there, we add it to some code that is called from the ibm_40p_init()
machine init function instead.
Since the alias is now only created during the machine init, we can remove
the object_property_del() completely.

Fixes: 654a36d8Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NThomas Huth <thuth@redhat.com>
Message-Id: <1534419358-10932-5-git-send-email-thuth@redhat.com>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It should save us some CPU cycles as these routines perform a lot of
checks.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Instead initialise the device via qdev to allow us to set device properties
directly as required.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Instead initialise the device via qdev to allow us to set device properties
directly as required.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Instead initialise the device via qdev to allow us to set device properties
directly as required.
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Acked-by: NHervé Poussineau <hpoussin@reactos.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

- prep machine is a fictional machine, so has no specifications. Which
  devices can be changed/added/removed without impact? Are interrupts
  correctly mapped?
- prep firmware (OHW) has support only for IDE drives (no SCSI).
  Booting from IDE has been broken approximatively 3 years ago, and nobody complained.
- OHW is limited on IDE boot to a specific set of OS loaders.
  These operating systems are of the 2004 time frame.
- OHW can use -kernel. Linux kernel freezes a long time after PS/2 mouse
  detection, and then screen becomes garbage. This was already broken in
  QEMU v2.7, 2 years ago, and nobody complained.

On the other side:
- 40p is a real machine, so emulation can be checked against
  hardware specifications
- OpenBIOS has support for SCSI block devices, including 40p LSI adapter
- OpenBIOS can start mostly all Linux kernels (including recent ones)
  and recent operating system (like NetBSD 7.1.2)
Signed-off-by: NHervé Poussineau <hpoussin@reactos.org>
[dwg: Drop prep from boot-serial test to avoid deprecation warnings]
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

This proposal moves all the related IRQ routines of the sPAPR machine
behind a sPAPR IRQ backend interface 'spapr_irq' to prepare for future
changes. First of which will be to increase the size of the IRQ number
space, then, will follow a new backend for the POWER9 XIVE IRQ controller.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Convert the devices in ppc405_uc away from using the old_mmio
MemoryRegion accessors:

 * opba's 32-bit and 16-bit accessors were just calling the
   8-bit accessors and assembling a big-endian order number,
   which we can do by setting the .impl.max_access_size to 1
   and the endianness to DEVICE_BIG_ENDIAN, and letting the
   core memory code do the assembly
 * ppc405_gpio's accessors were all just stubs
 * ppc4xx_gpt's 8-bit and 16-bit accessors were treating the
   access as invalid, which we can do by setting the
   .valid.min_access_size and .valid.max_access_size fields
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Switch the ref405ep_fpga device away from using the old_mmio
MemoryRegion accessors.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

The prep machine has some code which is stubs of accessors
for XCSR registers. This has been disabled via #if 0
since commit b6b8bd18 in 2004, and doesn't have any
actual interesting content. It also uses the deprecated
old_mmio accessor functions. Remove it entirely.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: NHervé Poussineau <hpoussin@reactos.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

This proposal introduces a new IRQ number space layout using static
numbers for all devices, depending on a device index, and a bitmap
allocator for the MSI IRQ numbers which are negotiated by the guest at
runtime.

As the VIO device model does not have a device index but a "reg"
property, we introduce a formula to compute an IRQ number from a "reg"
value. It should minimize most of the collisions.

The previous layout is kept in pre-3.1 machines raising the
'legacy_irq_allocation' machine class flag.
Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Signed-off-by: NCédric Le Goater <clg@kaod.org>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

VMStateDescription vmstate_spapr_cpu_state was added by commit
b9402026 (spapr_cpu_core: migrate per-CPU data) to migrate per-CPU
data with the required vmstate registration and unregistration calls.
However the unregistration is being done only from vcpu creation error path
and not from CPU delete path.

This causes migration to fail with the following error if migration is
attempted after a CPU unplug like this:
Unknown savevm section or instance 'spapr_cpu' 16
Additionally this leaves the source VM unresponsive after migration failure.

Fix this by ensuring the vmstate_unregister happens during CPU removal.
Fixing this becomes easier when vmstate (un)registration calls are moved to
vcpu (un)realize functions which is what this patch does.

Fixes: https://bugs.launchpad.net/qemu/+bug/1785972Reported-by: NSatheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: NBharata B Rao <bharata@linux.ibm.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

For the older machines (such as Mac and SPARC) the DT nodes representing
bootdevices for disk nodes are irregular for mainly historical reasons.

Since the majority of bootdevice nodes for these machines either do not have a
separate disk node or require different (custom) names then it is much easier
for processing to just disable all suffixes for a particular machine.

Introduce a new ignore_boot_device_suffixes MachineClass property to control
bootdevice suffix generation, defaulting to false in order to preserve
compatibility.
Suggested-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20180810124027.10698-1-mark.cave-ayland@ilande.co.uk>
Reviewed-by: NLaszlo Ersek <lersek@redhat.com>
Acked-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

The four interrupts of the PCI bus are connected to the same UIC pin
on the real Sam460ex. Evidence for this can be found in the UBoot
source for the Sam460ex in the Sam460ex.c file where
PCI_INTERRUPT_LINE is written. Change the ppc440_pcix model to behave
more like this.

This fixes the problem that can be observed when adding further PCI
cards that got their interrupt rotated to other interrupts than PCI
INT A. In particular, the bug was observed with an additional OHCI PCI
card or an ES1370 sound device.
Signed-off-by: NSebastian Bauer <mail@sebastianbauer.info>
Signed-off-by: NBALATON Zoltan <balaton@eik.bme.hu>
Tested-by: NSebastian Bauer <mail@sebastianbauer.info>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

Commit 51b0d834 changed error handling to report file name in error
message but forgot to move freeing it after usage. Noticed by Coverity.

Fixes: CID 1394217
Reported-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NBALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

This function was introduced between v2.11 and v2.12 to replace obsolete
ways of specifying the NUMA nodes for DIMMs.  It's used to find the correct
node for an LMB, by locating which DIMM object it lies within.

Unfortunately, one of the checks is inverted, so we check whether the
address is less than two different things, rather than actually checking
a range.  This introduced a regression, meaning that after a reboot qemu
will advertise incorrect node information for memory to the guest.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NGreg Kurz <groug@kaod.org>
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>

sam460ex_load_device_tree() handles nearly all possible errors by simply
exiting (within helper functions and macros).  It handles two early error
cases by returning an error.

There's no particular point to this, so make it handle those directly as
well, removing the need for the caller to handle a failure.  As a bonus it
gives us more specific error messages.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

The qemu_fdt_*() helper functions already exit with a message instead of
returning errors, so we don't need to check for errors in the caller.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>