Re: Build regressions/improvements in v4.9-rc1

From: Vineet Gupta
Date: Mon Oct 17 2016 - 12:59:51 EST

+CC Arnd, Michal

Hi Geert, Arnd

Need some guidance here.

On 10/17/2016 12:34 AM, Geert Uytterhoeven wrote:
>> 48 error regressions:
>> > + /home/kisskb/slave/src/arch/arc/include/asm/atomic.h: Error: bad instruction `llockd r2,[r0]': => 476
>> > + /home/kisskb/slave/src/arch/arc/include/asm/atomic.h: Error: bad instruction `llockd r2,[r13]': => 475


>> > + /home/kisskb/slave/src/arch/arc/include/asm/atomic.h: Error: bad instruction `scondd r4,[r8]': => 516
>> > + /home/kisskb/slave/src/arch/arc/include/asm/atomic.h: Error: bad instruction `scondd r6,[r3]': => 478
> arcv2/axs103_smp_defconfig

I'm thinking how to address this correctly.

This is due to the older version of compiler. The fix itself is trivial - add an
"call as-instr" construct in Makefile to get -DARC_TOOLS_SUPPORT_LLOCKD

However the atomic64 API variant (CONFIG_GENERIC_ATOMIC64 or arch native) which
gets included in build comes from Kconfig (ISA supports them or not). How do we
tie the Makefile info into the Kconfig.

We could trigger a build failure for invalid combinations of GENERIC_ATOMIC64 and
ARC_TOOLS_SUPPORT_LLOCKD but that would be less than ideal out of box experience.

Or the simpler solution is that kisskb upgrades the ARC GNU compiler ;-)