Re: [PATCH v3 5/6] powerpc/pseries: implement paravirt qspinlocks for SPLPAR

Segher Boessenkool
2020-07-23T20:31:04Z

On Thu, Jul 23, 2020 at 09:58:55PM +0200, peterz@infradead.org wrote:
> asm ("addb %[val], %b[var];"
> "cmovc %[sat], %[var];"
> : [var] "+r" (tmp)
> : [val] "ir" (val), [sat] "r" (sat)
> );

"var" (operand 0) needs an earlyclobber ("sat" is read after "var" is
written for the first time).

Segher