Re: [RFC PATCH v3 14/35] drivers/irqchip: Add SH7751 Internal INTC drivers.

On Wed, Oct 18, 2023 at 10:02 AM Thomas Gleixner <[email protected]> wrote:
> On Sat, Oct 14 2023 at 23:53, Yoshinori Sato wrote:
> > +config RENESAS_SH7751_INTC
> > +     bool "Renesas SH7751 Interrupt Controller"
> > +     depends on SH_DEVICE_TREE || COMPILE_TEST

> > +static inline void set_interrupt_registers(int ip)
> > +{
> > +     unsigned long __dummy;
> > +
> > +     asm volatile(
> > +#ifdef CONFIG_CPU_HAS_SR_RB
> > +                  "ldc       %2, r6_bank\n\t"
> > +#endif
> > +                  "stc       sr, %0\n\t"
> > +                  "and       #0xf0, %0\n\t"
> > +                  "shlr2     %0\n\t"
> > +                  "cmp/eq    #0x3c, %0\n\t"
> > +                  "bt/s      1f      ! CLI-ed\n\t"
> > +                  " stc      sr, %0\n\t"
> > +                  "and       %1, %0\n\t"
> > +                  "or        %2, %0\n\t"
> > +                  "ldc       %0, sr\n"
> > +                  "1:"
> > +                  : "=&z" (__dummy)
> > +                  : "r" (~0xf0), "r" (ip << 4)
> > +                  : "t");
>
> Why has this to be ASM and cannot be done in C with the existing
> accessors? Also this really lacks a comment what this is actually doing.

This will play not very well with the "|| COMPILE_TEST" ;-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds