The patch below fixes an arithmetic wrap-around issue on 32bit machines
using smp-tbsync. Without this patch a timebase value over
0x000000007fffffff will hang the boot process while bringing up
secondary CPUs.
Signed-off-by: Adrian Cox <adrian@humboldt.co.uk>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Per email discussion, it appears that rtas_stop_self()
and pSeries_mach_cpu_die() should not be compiled if
CONFIG_HOTPLUG_CPU is not defined. This patch adds
#ifdefs around these bits of code.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Rewrite local_get_flags and local_irq_disable to use r13 explicitly,
to avoid the risk that gcc will split get_paca()->soft_enabled into a
sequence unsafe against preemption. Similar care in local_irq_restore.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
powerpc: Merge 32 and 64 bits asm-powerpc/io.h
The rework on io.h done for the new hookable accessors made it easier,
so I just finished the work and merged 32 and 64 bits io.h for arch/powerpc.
arch/ppc still uses the old version in asm-ppc, there is just too much gunk
in there that I really can't be bothered trying to cleanup.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds full cell iommu support (and iommu disabled mode).
It implements mapping/unmapping of iommu pages on demand using the
standard powerpc iommu framework. It also supports running with
iommu disabled for machines with less than 2GB of memory. (The
default is off in that case, though it can be forced on with the
kernel command line option iommu=force).
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch makes dma_alloc_coherent() use node local allocation when
using the direct DMA ops. The node is obtained from the new device
extension. If no such extension is present, the current node is used.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds an optional global offset that can be added to DMA addresses
when using the direct DMA operations.
That brings it a step closer to the 32 bits direct DMA operations, and makes
it useable on Cell when the MMU is disabled and we are using a spider
southbridge.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch reworks the way iSeries hooks on PCI IO operations (both MMIO
and PIO) and provides a generic way for other platforms to do so (we
have need to do that for various other platforms).
While reworking the IO ops, I ended up doing some spring cleaning in
io.h and eeh.h which I might want to split into 2 or 3 patches (among
others, eeh.h had a lot of useless stuff in it).
A side effect is that EEH for PIO should work now (it used to pass IO
ports down to the eeh address check functions which is bogus).
Also, new are MMIO "repeat" ops, which other archs like ARM already had,
and that we have too now: readsb, readsw, readsl, writesb, writesw,
writesl.
In the long run, I might also make EEH use the hooks instead
of wrapping at the toplevel, which would make things even cleaner and
relegate EEH completely in platforms/iseries, but we have to measure the
performance impact there (though it's really only on MMIO reads)
Since I also need to hook on ioremap, I shuffled the functions a bit
there. I introduced ioremap_flags() to use by drivers who want to pass
explicit flags to ioremap (and it can be hooked). The old __ioremap() is
still there as a low level and cannot be hooked, thus drivers who use it
should migrate unless they know they want the low level version.
The patch "arch provides generic iomap missing accessors" (should be
number 4 in this series) is a pre-requisite to provide full iomap
API support with this patch.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When enabled in Kconfig, it will pick up any of_platform_device
matching it's match list (currently type "pci", "pcix", "pcie",
or "ht" and setup a PHB for it.
Platform must provide a ppc_md.pci_setup_phb() for it to work
(for doing the necessary initialisations specific to a given PHB
like setting up the config space ops).
It's currently only available on 64 bits as the 32 bits PCI code
can't quite cope with it in it's current form. I will fix that
later.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a "parent" struct device to our PCI host bridge data structure so that
PCI can be rooted off another device in sysfs.
Note that arch/ppc doesn't use it, only arch/powerpc, though it's available
for both 32 and 64 bits.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The BUID is the first entry of a PCI host bridge "reg" property.
Now that PCI busses can be anywhere in the device-tree, we need to
fully translate the value there to a CPU physical address before
we can use it with RTAS.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
When parsing the OF "ranges" properties of PCI host busses to determine
the mapping of a PCI bus, we need to translate the "parent" address using
the prom_parse.c routines in order to obtain a CPU physical address.
This wasn't necessary while PCI busses were always at the root of the
device-tree but this is no longer the case on Cell where they can be
anywhere in the tree.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch completely refactors DMA operations for 64 bits powerpc. 32 bits
is untouched for now.
We use the new dev_archdata structure to add the dma operations pointer
and associated data to struct device. While at it, we also add the OF node
pointer and numa node. In the future, we might want to look into merging
that with pci_dn as well.
The old vio, pci-iommu and pci-direct DMA ops are gone. They are now replaced
by a set of generic iommu and direct DMA ops (non PCI specific) that can be
used by bus types. The toplevel implementation is now inline.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch first splits of_device.c and of_platform.c, the later containing
the bits relative to of_platform_device's. On the "breaks" side of things,
drivers uisng of_platform_device(s) need to include asm/of_platform.h now
and of_(un)register_driver is now of_(un)register_platform_driver.
In addition to a few utility functions to locate of_platform_device(s),
the main new addition is of_platform_bus_probe() which allows the platform
code to trigger an automatic creation of of_platform_devices for a whole
tree of devices.
The function acts based on the type of the various "parent" devices encountered
from a provided root, using either a default known list of bus types that can be
"probed" or a passed-in list. It will only register devices on busses matching
that list, which mean that typically, it will not register PCI devices, as
expected (since they will be picked up by the PCI layer).
This will be used by Cell platforms using 4xx-type IOs in the Axon bridge
and can be used by any embedded-type device as well.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds new dcr_map/dcr_read/dcr_write accessors for DCRs that
can be used by drivers to transparently address either native DCRs or
memory mapped DCRs. The implementation for memory mapped DCRs is done
after the binding being currently worked on for SLOF and the Axon
chipset. This patch enables it for the cell native platform
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
These were inherited from ARCH=ppc, but are not needed since parsing of interrupts
should be done via the of_* functions (who can do swizzling). If we ever need to
do non-standard swizzling on bridges without a device-node, then we might add
back a slightly different version of ppc_md.pci_swizzle but for now, that is not
the case.
I removed the couple of calls for these in 83xx. If that breaks something, then
there is a problem with the device-tree on these.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch reworks the way IRQs are fixed up on PCI for arch powerpc.
It makes pci_read_irq_line() called by default in the PCI code for
devices that are probed, and add an optional per-device fixup in
ppc_md for platforms that really need to correct what they obtain
from pci_read_irq_line().
It also removes ppc_md.irq_bus_setup which was only used by pSeries
and should not be needed anymore.
I've also removed the pSeries s7a workaround as it can't work with
the current interrupt code anyway. I'm trying to get one of these
machines working so I can test a proper fix for that problem.
I also haven't updated the old-style fixup code from 85xx_cds.c
because it's actually buggy :) It assigns pci_dev->irq hard coded
numbers which is no good with the new IRQ mapping code. It should
at least use irq_create_mapping(NULL, hard_coded_number); and possibly
also set_irq_type() to set them as level low.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a check for a null ppc_md.init_early to allow platforms that
don't require an init_early routine to just set this member to null.
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Make nvram_64.o dependent on 64bit, not on MULTIPLATFORM.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
dev_t boot_dev is declared in arch/powerpc/kernel/setup_32.c
and in arch/powerpc/kernel/setup_64.c but not used in these files.
It is only used in arch/powerpc/platforms/powermac/setup.c, so make
it static in this file.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Since iSeries is merged to MULTIPLATFORM, there is no way to build a 64bit
kernel without MULTIPLATFORM, so PPC_MULTIPLATFORM can be removed in
64bit-only files.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Since iSeries is merged to MULTIPLATFORM, there is no way to build a 64bit
kernel without MULTIPLATFORM, so PPC_MULTIPLATFORM can be removed in
64bit-only files.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The enablement of 64k pages on pseries platforms exposed a bug in
the RTAS mechanism for updating firmware. RTAS assumes 4k for flash
block and list sizes, and use of any other sizes results in a failure,
even though PAPR does not specify any such requirement.
This patch changes the rtas_flash module to force the use of 4k memory
block and list sizes when preparing and sending a firmware image to
RTAS. The rtas_flash function now uses a slab cache of 4k blocks with
4k alignment, rather than get_zeroed_page(), to allocate the memory for
the flash blocks and lists. The 4k alignment requirement is specified
in PAPR.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It turns out that the linker warnings on 64-bit powerpc about "section
blah exceeds stub group size" were being triggered by conditional
branches in head_64.S branching to global symbols, whether in
head_64.S or in other files. This eliminates the warnings by making
some global symbols in head_64.S no longer global, and by rearranging
some branches.
Signed-off-by: Paul Mackerras <paulus@samba.org>
[ Yee-haa. Maybe I'll notice newly introduced real warnings now - Linus ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The alignment exception used to only check the exception table for
-EFAULT, not for other errors. That opens an oops window if we can
coerce the kernel into getting an alignment exception for other reasons
in what would normally be a user-protected accessor, which can be done
via some of the futex ops. This fixes it by always checking the
exception tables.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The 10Gigabit ethernet device drivers appear to be able to chew
up all 256MB of TCE mappings on pSeries systems, as evidenced by
numerous error messages:
iommu_alloc failed, tbl c0000000010d5c48 vaddr c0000000d875eff0 npages 1
Some experimentation indicates that this is essentially because
one 1500 byte ethernet MTU gets mapped as a 64K DMA region when
the large 64K pages are enabled. Thus, it doesn't take much to
exhaust all of the available DMA mappings for a high-speed card.
This patch changes the iommu allocator to work with its own
unique, distinct page size. Although the patch is long, its
actually quite simple: it just #defines a distinct IOMMU_PAGE_SIZE
and then uses this in all the places that matter.
As a side effect, it also dramatically improves network performance
on platforms with H-calls on iommu translation inserts/removes (since
we no longer call it 16 times for a 1500 bytes packet when the iommu HW
is still 4k).
In the future, we might want to make the IOMMU_PAGE_SIZE a variable
in the iommu_table instance, thus allowing support for different HW
page sizes in the iommu itself.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fixed a compile error in building the 85xx support with oprofile, and in
the process cleaned up some issues with the fsl_booke performance monitor
code.
* Reorganized FSL Book-E performance monitoring code so that the 7450
wouldn't be built if the e500 was, and cleaned it up so it was more
self-contained.
* Added a cpu_setup function for FSL Book-E. The original
cpu_setup function prototype had no arguments, assuming that
the reg_setup function would copy the required information into
variables which represented the registers. This was silly for
e500, since it has 1 register per counter (rather than 3 for
all counters), so the code has been restructured to have
cpu_setup take the current counter config array as an argument,
with op_powerpc_setup() invoking op_powerpc_cpu_setup() through
on_each_cpu(), and op_powerpc_cpu_setup() invoking the
model-specific cpu_setup function with an argument. The
argument is ignored on all other platforms at present.
* Fixed a confusing line where a trinary operator only had two
arguments
Signed-off-by: Andrew Fleming <afleming@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch fixes a few issues in offb:
- A test was inverted causing the palette hack to never work
(no device node was passed down to the init function)
- Some cards seem to have their assigned-addresses property in a random
order, thus we need to try using of_get_pci_address() first, which will
fail if it's not a PCI device, and fallback to of_get_address() in that
case. of_get_pci_address() properly parsees assigned-addresses to test
the BAR number and thus will get it right whatever the order is.
- Some cards (like GXT4500) provide a linebytes of 0xffffffff in the
device-tree which does no good. This patch handles that by using the
screen width when that happens. (Also fixes btext.c while at it).
- Add detection of the GXT4500 in addition to the GXT2000 for the
palette hacks (we use the same hack, palette is linear in register space
at offset 0x6000).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Add a vmlinux.lds.h helper macro for defining the eight-level initcall table,
teach all the architectures to use it.
This is a prerequisite for a patch which performs initcall synchronisation for
multithreaded-probing.
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
[ Added AVR32 as well ]
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a cpufreq backend driver to enable frequency scaling on cell.
Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This moves the cell idle function to use the default cpu_idle
with a special power_save callback, like all other platforms
except iSeries already do.
It also makes it possible to disable this power_save function
with a new powerpc-specific boot option "powersave=off".
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds two functions to create and remove sysfs attributes and
attribute_group to all cpus. That allows to register sysfs attributes in
a subdirectory like: /sys/devices/system/cpu/cpuX/group_name/what_ever
This will be used by cbe_thermal to group all attributes dealing with
thermal support in one directory.
Signed-of-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It makes for a friendlier API if irq_dispose_mapping(NO_IRQ) is a
nop, rather than triggering a WARN_ON.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Fix a const'ification related warning with device_is_compatible()
and friends related to get_property() not properly having const
on it's input device node argument.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The Cell CPU timebase has an erratum. When reading the entire 64 bits
of the timebase with one mftb instruction, there is a handful of cycles
window during which one might read a value with the low order 32 bits
already reset to 0x00000000 but the high order bits not yet incremeted
by one. This fixes it by reading the timebase again until the low order
32 bits is no longer 0. That might introduce occasional latencies if
hitting mftb just at the wrong time, but no more than 70ns on a cell
blade, and that was considered acceptable.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch adds support for feature fixups in modules. This involves
adding support for R_PPC64_REL64 relocs to the 64 bits module loader.
It also modifies modpost.c to ignore the powerpc fixup sections (or it
would warn when used in .init.text).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This patch reworks the feature fixup mecanism so vdso's can be fixed up.
The main issue was that the construct:
.long label (or .llong on 64 bits)
will not work in the case of a shared library like the vdso. It will
generate an empty placeholder in the fixup table along with a reloc,
which is not something we can deal with in the vdso.
The idea here (thanks Alan Modra !) is to instead use something like:
1:
.long label - 1b
That is, the feature fixup tables no longer contain addresses of bits of
code to patch, but offsets of such code from the fixup table entry
itself. That is properly resolved by ld when building the .so's. I've
modified the fixup mecanism generically to use that method for the rest
of the kernel as well.
Another trick is that the 32 bits vDSO included in the 64 bits kernel
need to have a table in the 64 bits format. However, gas does not
support 32 bits code with a statement of the form:
.llong label - 1b (Or even just .llong label)
That is, it cannot emit the right fixup/relocation for the linker to use
to assign a 32 bits address to an .llong field. Thus, in the specific
case of the 32 bits vdso built as part of the 64 bits kernel, we are
using a modified macro that generates:
.long 0xffffffff
.llong label - 1b
Note that is assumes that the value is negative which is enforced by
the .lds (those offsets are always negative as the .text is always
before the fixup table and gas doesn't support emiting the reloc the
other way around).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
There are currently two versions of the functions for applying the
feature fixups, one for CPU features and one for firmware features. In
addition, they are both in assembly and with separate implementations
for 32 and 64 bits. identify_cpu() is also implemented in assembly and
separately for 32 and 64 bits.
This patch replaces them with a pair of C functions. The call sites are
slightly moved on ppc64 as well to be called from C instead of from
assembly, though it's a very small change, and thus shouldn't cause any
problem.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The original problem that inspired this patch was solved quite some time
ago (Turning off PCI didn't work), but this patch neatens things up a
little (I think), by putting all the PCI stuff inside a single CONFIG_PCI
block. It also removes the OF PCI bus matching entries if CONFIG_PCI is
off.
Signed-off-by: Paul Mackerras <paulus@samba.org>
In calculating stolen time, we were trying to actually account for time
spent in the hypervisor. We don't really have enough information to do
that accurately, so don't try. Instead, we now calculate stolen time as
time that the current cpu thread is not actually dispatching instructions.
On chips without a PURR, we cannot do this, so stolen time will always
be zero. On chips with a PURR, this is merely the difference between
the elapsed PURR values and the elapsed TB values.
This gives us much more sane vaules from tools such as mpstat, even if
they are still a bit strange e.g. 2 busy threads on one cpu will both
appear to have 50% user time and 50% stolen time while 1 busy thread on
a cpu will look like 100% user on one of them and 100% idle on the other.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The lazy IRQ disable patch missed a couple of places where the
interrupt enable flags need to be restored correctly. First, we
weren't restoring the paca->hard_enabled flag on interrupt exit.
Instead of saving it on entry, we compute it from the MSR_EE bit
in the MSR we are restoring at exit. Secondly, the MMU hash miss
code was clearing both paca->soft_enabled and paca->hard_enabled
but not restoring them in the case where hash_page was able to
resolve the miss from the Linux page tables.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Without this patch, on an idle system I get:
cpu-power-0:21.638
cpu-power-1:27.102
cpu-power-2:29.343
cpu-power-3:25.784
Total: 103.8W
With this patch:
cpu-power-0:11.730
cpu-power-1:17.185
cpu-power-2:18.547
cpu-power-3:17.528
Total: 65.0W
If I lower HZ to 100, I can get it as low as:
cpu-power-0:10.938
cpu-power-1:16.021
cpu-power-2:17.245
cpu-power-3:16.145
Total: 60.2W
Another (older) Quad G5 went from 54W to 39W at HZ=250.
Coming back out of Deep Nap takes 40-70 cycles longer than coming back
from just Nap (which already takes quite a while). I don't think it'll
be a performance issue (interrupt latency on an idle system), but in
case someone does measurements feel free to report them.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This implements a lazy strategy for disabling interrupts. This means
that local_irq_disable() et al. just clear the 'interrupts are
enabled' flag in the paca. If an interrupt comes along, the interrupt
entry code notices that interrupts are supposed to be disabled, and
clears the EE bit in SRR1, clears the 'interrupts are hard-enabled'
flag in the paca, and returns. This means that interrupts only
actually get disabled in the processor when an interrupt comes along.
When interrupts are enabled by local_irq_enable() et al., the code
sets the interrupts-enabled flag in the paca, and then checks whether
interrupts got hard-disabled. If so, it also sets the EE bit in the
MSR to hard-enable the interrupts.
This has the potential to improve performance, and also makes it
easier to make a kernel that can boot on iSeries and on other 64-bit
machines, since this lazy-disable strategy is very similar to the
soft-disable strategy that iSeries already uses.
This version renames paca->proc_enabled to paca->soft_enabled, and
changes a couple of soft-disables in the kexec code to hard-disables,
which should fix the crash that Michael Ellerman saw. This doesn't
yet use a reserved CR field for the soft_enabled and hard_enabled
flags. This applies on top of Stephen Rothwell's patches to make it
possible to build a combined iSeries/other kernel.
Signed-off-by: Paul Mackerras <paulus@samba.org>
