powerpc/ppc64: Allow allmodconfig to build (finally !)

[Alan Modra]

On Tue, May 13, 2014 at 10:16:51PM -0700, Guenter Roeck wrote:
> any idea what might cause this one, by any chance ?
> 
> arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
> (.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI against symbol `interrupt_base_book3e' defined in .text section in arch/powerpc/kernel/built-in.o
> arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
> (.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI against symbol `interrupt_end_book3e' defined in .text section in arch/powerpc/kernel/built-in.o
> arch/powerpc/kernel/built-in.o: In function `exc_debug_debug_book3e':
> 
> I see this if I try to build powerpc:ppc64e_defconfig or powerpc:chroma_defconfig
> with gcc 4.8.2 and binutils 2.24.

Blame me.  I changed the ABI, something that had to be done but
unfortunately happens to break the booke kernel code.  When building
up a 64-bit value with lis, ori, shl, oris, ori or similar sequences,
you now should use @high and @higha in place of @h and @ha.  @h and
@ha (and their associated relocs R_PPC64_ADDR16_HI and
R_PPC64_ADDR16_HA) now report overflow if the value is out of 32-bit
signed range.  ie. @h and @ha assume you're building a 32-bit value.
This is needed to report out-of-range -mcmodel=medium toc pointer
offsets in @toc at h and @toc at ha expressions, and for consistency I did
the same for all other @h and @ha relocs.

-- 
Alan Modra
Australia Development Lab, IBM