[U-Boot] [PATCH v2] timer: add High Precision Event Timers (HPET) support

[Ivan Gorinov]

On Fri, Mar 30, 2018 at 10:46:40PM +0300, Andy Shevchenko wrote:

> > +       writel(0, regs + HPET_MAIN_COUNT_L);
> > +       writel(0, regs + HPET_MAIN_COUNT_H);
> 
> Can we use writeq() here?

I don't see readq/writeq defined for x86, even x86_64.

> > +               tl = readl(regs + HPET_MAIN_COUNT_L);
> > +               th = readl(regs + HPET_MAIN_COUNT_H);
> 
> Ditto.

If readq() is defined as two read operations in 32-bit code, main counter
rollover (low part overflow, high part increment) can happen between them.