Otherwise, we get a debug traceback due to the use of
smp_processor_id() (or get_paca()) inside hard_smp_processor_id().
mpic_host_map() is just looking for a default CPU, so it doesn't matter
if we migrate after getting the CPU ID.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Temporarily work around an ICE we are seeing while building
in little endian mode:

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57134Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

POWER7 takes alignment exceptions on some unaligned addresses, so
disable HAVE_EFFICIENT_UNALIGNED_ACCESS. This fixes an early boot
issue in the printk code.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch allows the kbuild system to successfully compile a kernel
for the little endian PowerPC64 architecture. A subsequent patch
will add the CONFIG_CPU_LITTLE_ENDIAN kernel config option which
must be set to build such a kernel.

If cross compiling, CROSS_COMPILE must point to a suitable toolchain
(compiled for the powerpc64le-linux and powerpcle-linux targets).
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There are a number of KVM issues with little endian builds.
We are working on fixing them, but in the meantime disable
it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

pnv_pci_setup_bml_iommu was missing a byteswap of a device
tree property.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Sparse caught an issue where opal_set_rtc_time was incorrectly
byteswapping. Also fix a number of sparse warnings.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The powernv exception handlers are not ready to take exceptions
in little endian mode, so disable them.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We need to distinguish between big endian and little endian
environments, so fix uname to return the right thing.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We need to fix some endian issues in our memcpy code. For now
just enable the generic memcpy routine for little endian builds.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We need to fix some endian issues in our checksum code. For now
just enable the generic checksum routines for little endian builds.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Things are complicated by the fact that VSX elements are big
endian ordered even in little endian mode. 8 byte loads and
stores also write to the top 8 bytes of the register.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Handle most unaligned load and store faults in little
endian mode. Strings, multiples and VSX are not supported.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The TS_FPR macro selects the FPR component of a VSX register (the
high doubleword). emulate_vsx is using this macro to get the
address of the associated VSX register. This happens to work on big
endian, but fails on little endian.

Replace it with an explicit array access.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The alignment handler assumes big endian ordering when selecting
the low word of a 64bit floating point value. Use the existing
union which works in both little and big endian.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Use swab64/32/16 instead of open coding it.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Create a trampoline that works in either endian and flips to
the expected endian. Use it for primary and secondary thread
entry as well as RTAS and OF call return.

Credit for finding the magic instruction goes to Paul Mackerras
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch will have powerpc include the appropriate generic endianness
header depending on what the compiler reports.
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We always take signals in big endian which is wrong. Signals
should be taken in native endian.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We need to set MSR_LE in kernel and userspace for little endian builds
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The powerpc word-at-a-time functions are big endian specific.
Bring in the x86 version in order to support little endian builds.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This patch maps the MMIO functions for 32bit PowerPC to their
appropriate instructions depending on CPU endianness.

The macros used to create the corresponding inline functions are also
renamed by this patch. Previously they had BE or LE in their names which
was misleading - they had nothing to do with endianness, but actually
created different instruction forms so their new names reflect the
instruction form they are creating (D-Form and X-Form).

Little endian 64bit PowerPC is not supported, so the lack of mappings
(and corresponding breakage) for that case is intentional to bring the
attention of anyone doing a 64bit little endian port. 64bit big endian
is unaffected.

[ Added 64 bit versions - Anton ]
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The elements within VSX loads and stores are big endian ordered
regardless of endianness. Our VSX context save/restore code uses
lxvd2x and stxvd2x which is a 2x doubleword operation. This means
the two doublewords will be swapped and we have to perform another
swap to undo it.

We need to do this on save and restore.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

FPRs overlap the high 64bits of the first 32 VSX registers. The
ptrace FP read/write code assumes big endian ordering and grabs
the lowest 64 bits.

Fix this by using the TS_FPR macro which does the right thing.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The FPRs overlap the high doublewords of the first 32 VSX registers.
Fix TS_FPROFFSET and TS_VSRLOWOFFSET so we access the correct fields
in little endian mode.

If VSX is disabled the FPRs are only one doubleword in length so
TS_FPROFFSET needs adjusting in little endian.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Fix the permute loops for little endian.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

irq_exit() is now called on the irq stack, which can trigger a switch to
the softirq stack from the irq stack.  If an interrupt happens at that
point, we will not properly detect the re-entrancy and clobber the
original return context on the irq stack.

This fixes it.  The side effect is to prevent all nesting from softirq
stack to irq stack even in the "safe" case but it's simpler that way and
matches what x86_64 does.
Reported-by: NCédric Le Goater <clg@fr.ibm.com>
Tested-by: NCédric Le Goater <clg@fr.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>