Re: [PATCH] Make MIPS dynamic clocksource/clockevent clock code generic

[Mikael Pettersson <mikpe@it.uu.se>]

Thomas Gleixner writes:
 > > +static inline void clockevent_set_clock(struct clock_event_device *dev, u32 hz)
 > > +{
 > > +	u64 temp;
 > > +	u32 shift;
 > > +
 > > +	/* Find a shift value */
 > > +	for (shift = 32; shift > 0; shift--) {
 > > +		temp = (u64) hz << shift;
 > > +		do_div(temp, NSEC_PER_SEC);
 > > +		if ((temp >> 32) == 0)
 > > +			break;
 > > +	}
 > > +	dev->shift = shift;
 > > +	dev->mult = (u32) temp;
 > > +}
 > > +
 > > +
 > > +static inline void clocksource_set_clock(struct clocksource *cs, u32 hz)
 > > +{
 > > +	u64 temp;
 > > +	u32 shift;
 > > +
 > > +	/* Find a shift value */
 > > +	for (shift = 32; shift > 0; shift--) {
 > > +		temp = (u64) NSEC_PER_SEC << shift;
 > > +		do_div(temp, hz);
 > > +		if ((temp >> 32) == 0)
 > > +			break;
 > > +	}
 > > +	cs->shift = shift;
 > > +	cs->mult = (u32) temp;
 > > +}
 > > +
 > 
 > So that's the same function twice, right ?

They are similar but not identical:

 > > +		temp = (u64) hz << shift;
 > > +		do_div(temp, NSEC_PER_SEC);

vs

 > > +		temp = (u64) NSEC_PER_SEC << shift;
 > > +		do_div(temp, hz);

I suppose both functions could be implemented by a suitably
parametric third function, but IMO that would just obscure things.

Making them non-inline I fully agree with.