Re: [PATCH 1/6 v6] SGI RTC: add generic system interrupt

Ingo Molnar
2009-03-03T15:35:14Z

* Dimitri Sivanich <sivanich@sgi.com> wrote:

> This patch allocates a system interrupt vector for various
> platform specific uses.

this is really ugly.

Also, why are all these symbols exported? There's no need to
build the UV RTC driver as a module. It's either built-in or not
built-in - it's small enough.

this stuff:

> +/* Function pointer for generic interrupt vector handling */
> +static void (*generic_interrupt_extension)(void);
> +static char generic_show_string[28];
> +static char generic_show_prefix[6];
> +
> +int is_generic_interrupt_registered()
> +{
> + if (generic_interrupt_extension)
> + return 1;
> + else
> + return 0;
> +}
> +
> +char *generic_interrupt_string(void)
> +{
> + return generic_show_string;
> +}
> +
> +char *generic_interrupt_prefix(void)
> +{
> + return generic_show_prefix;
> +}

is SMP unsafe, etc. etc. - not something we should ever call
from a module. We just shouldnt do it in this form. What
necessiates it?

All we need is:

> + /* generic IPI for platform specific use */
> + alloc_intr_gate(GENERIC_INTERRUPT_VECTOR, generic_interrupt);

plus one trivial callback function - and then the UV platform
uses it for its own purpose. It's not like two platforms will be
running at once so there's no locking needed, etc.

> +#ifdef CONFIG_X86_64
> +extern void generic_interrupt(void);
> +#endif

in any case please make it symmetric across 32-bit and 64-bit -
even though UV is 64-bit only.

Ingo