> -----Original Message----- > From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- > owner@xxxxxxxxxxxxxxx] On Behalf Of Tony Lindgren > Sent: Thursday, September 02, 2010 11:13 PM > To: Russell King - ARM Linux > Cc: linux-omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > Bryan Wu; Will Deacon > Subject: Re: [PATCH 1/6] ARM: Add inline function smp_on_up() for early > init testing > > * Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> [100902 10:00]: > > On Thu, Sep 02, 2010 at 09:18:47AM -0700, Tony Lindgren wrote: > > > > > --- a/arch/arm/include/asm/smp_plat.h > > > +++ b/arch/arm/include/asm/smp_plat.h > > > @@ -39,4 +39,20 @@ static inline int cache_ops_need_broadcast(void) > > > #define UP(instr...) _str(instr) > > > #endif > > > > > > +static inline int smp_on_up(void) > > > +{ > > > +#ifdef CONFIG_SMP_ON_UP > > > + int smp_on_up; > > > + > > > + asm( \ > > > + SMP(mov %0, #0) \ > > > + UP(mov %0, #1) \ > > > + : "=r" (smp_on_up)); > > > + > > > + return smp_on_up; > > > +#else > > > + return 0; > > > +#endif > > > > I think this is the wrong approach - rather than a function which tells > us > > just if we are a SMP kernel running on UP, why not something which > returns > > whether we're running on SMP and use that to eliminate some of these > ifdefs? > > Sure. Will has something like this in his patches: > > static inline int cpu_is_part_of_mp_system(void) > { > u32 mpidr; > asm volatile("mrc p15, 0, %0, c0, c0, 5" : "=r" (mpidr)); > return (mpidr >> 31) ? !(mpidr >> 30) : 0; > } I guess this register is only available on MP Core extensions. Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
