[PATCH] [POWERPC] Add IRQSTACKS support on ppc32

[Kumar Gala]

On Apr 28, 2008, at 12:17 AM, Paul Mackerras wrote:
> Kumar Gala writes:
>
>> * Added allocation and initialization of the irq stacks.  We limit  
>> the
>>  stacks to be in lowmem for ppc32.
>> * Implemented ppc32 versions of call_do_softirq() and  
>> call_handle_irq()
>>  to switch the stack pointers
>> * Reworked how we do stack overflow detection.  We now keep around  
>> the
>>  limit of the stack in the thread_struct and compare against the  
>> limit
>>  to see if we've overflowed.  We can now use this on ppc64 if  
>> desired.
>
> Mostly looks great.  One minor nit is that this ifdef could disappear
> entirely now:

How do you figure?  If we want to maintain it as a config option (for  
at least 2.6.26) we  either need this ifdef or a dummy irq_ctx_init().


>> @@ -352,7 +356,7 @@ void __init init_IRQ(void)
>> {
>> 	if (ppc_md.init_IRQ)
>> 		ppc_md.init_IRQ();
>> -#ifdef CONFIG_PPC64
>> +#ifdef CONFIG_IRQSTACKS
>> 	irq_ctx_init();
>> #endif
>
> Since it looks pretty much exactly like what 64-bit already does, and
> it's under a config option, I withdraw my objection to it going into
> 2.6.26.

:)

- k