[RFC PATCH 06/13] arm64: percpu: Add infrastructure for preemptible this_cpu_*() ops

[Mark Rutland]

On Tue, Jul 28, 2026 at 06:49:12PM +0200, Peter Zijlstra wrote:
> On Tue, Jul 28, 2026 at 04:53:52PM +0100, Mark Rutland wrote:
> 
> > > > +#define ____PCPU_GPRS_BEGIN(gprs, pcp, off, addr)			\
> > > > +	__DEFINE_ASM_GPR_NUMS						\
> > > > +	__DEFINE_ASM_GPR_ALIASES					\
> > > > +	"	mov w" off ", #" __VAL_PCPU_GPRS(pcp, off, addr) "\n"	\
> > > > +	"	strh	w" off ", " gprs "\n"				\
> > > > +	__KERN_ASM_CPU_OFFSET(off) "\n"
> > > 
> > > Can this macro also generate a readable comment for those few of us
> > > building the .i file ?
> > 
> > Do you mean for __VAL_PCPU_GPRS, or ____PCPU_GPRS_BEGIN() ?
> 
> I was thinking BEGIN, but whatever is easiest, the __VAL thing is only
> ever used in BEGIN anyway.
> 
> > I can happily add comments for either (and the corresponding ENDs).
> 
> Not sure the comment makes sense for end, that's simply storing 0 and
> seems clear enough.

FWIW, for v2 I've added the following to ____PCPU_GPRS_BEGIN():

	"// ____PCPU_GPRS_BEGIN(" gprs ", " pcp ", " off ", " addr")\n"

... which should make that easy to spot, and surfaces the exact
registers used.

Mark.