Re: [PATCH][MIPS][1/7] AR7: core support

[Matteo Croce <technoboy85@gmail.com>]

Il Saturday 08 September 2007 19:40:20 Atsushi Nemoto ha scritto:
> > diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
> > index 6379003..75a46ba 100644
> > --- a/arch/mips/kernel/traps.c
> > +++ b/arch/mips/kernel/traps.c
> > @@ -1075,9 +1075,23 @@ void *set_except_vector(int n, void *addr)
> >  
> >  	exception_handlers[n] = handler;
> >  	if (n == 0 && cpu_has_divec) {
> > +#ifdef CONFIG_AR7
> > +		/* lui k0, 0x0000 */
> > +		*(volatile u32 *)(CAC_BASE+0x200) =
> > +				0x3c1a0000 | (handler >> 16);
> > +		/* ori k0, 0x0000 */
> > +		*(volatile u32 *)(CAC_BASE+0x204) =
> > +				0x375a0000 | (handler & 0xffff);
> > +		/* jr k0 */
> > +		*(volatile u32 *)(CAC_BASE+0x208) = 0x03400008;
> > +		/* nop */
> > +		*(volatile u32 *)(CAC_BASE+0x20C) = 0x00000000;
> > +		flush_icache_range(CAC_BASE+0x200, CAC_BASE+0x210);
> > +#else
> >  		*(volatile u32 *)(ebase + 0x200) = 0x08000000 |
> >  		                                 (0x03ffffff & (handler >> 2));
> >  		flush_icache_range(ebase + 0x200, ebase + 0x204);
> > +#endif
> >  	}
> >  	return (void *)old_handler;
> >  }
> 
> Runtime checking, something like this would be better than ifdef:
> 
> 	if ((handler ^ (ebase + 4)) & 0xfc000000)
> 		/* use jr */
> 		...
> 	} else {
> 		/* use j */
> 		...
> 	}
This will not make the code bigger? What's wrong with #ifdef?