[PATCH] arm64: Fix compile error seen in non-SMP builds

[Guenter Roeck]

On Mon, Oct 20, 2014 at 06:22:09PM +0100, Catalin Marinas wrote:
> On Sat, Oct 11, 2014 at 02:15:34AM +0100, Guenter Roeck wrote:
> > Fix:
> > 
> > In file included from ./arch/arm64/include/asm/irq_work.h:4:0,
> >         from include/linux/irq_work.h:46,
> >         from include/linux/perf_event.h:49,
> >         from include/linux/ftrace_event.h:9,
> >         from include/trace/syscall.h:6,
> >         from include/linux/syscalls.h:81,
> >         from init/main.c:18:
> > ./arch/arm64/include/asm/smp.h:24:3:
> > 	error: #error "<asm/smp.h> included in non-SMP build"
> >  # error "<asm/smp.h> included in non-SMP build"
> >    ^
> > ./arch/arm64/include/asm/smp.h:27:0: warning: "raw_smp_processor_id" redefined
> >  #define raw_smp_processor_id() (current_thread_info()->cpu)
> >  ^
> > 
> > and:
> > 
> > In file included from ./arch/arm64/include/asm/irq_work.h:4:0,
> >         from include/linux/irq_work.h:46,
> >         from kernel/irq_work.c:11:
> > ./arch/arm64/include/asm/smp_plat.h:56:30:
> >         error: ‘NR_CPUS’ undeclared here (not in a function)
> >         extern u64 __cpu_logical_map[NR_CPUS];
> > 
> > by providing a helper function in smp_plat.h, similar to the arm implementation,
> > and by removing NR_CPUS from smp_plat.h.
> > 
> > Fixes: 3631073659d0 ("arm64: Tell irq work about self IPI support")
> > Cc: Frederic Weisbecker <fweisbec at gmail.com>
> > Signed-off-by: Guenter Roeck <linux at roeck-us.net>
> 
> Isn't something like this simpler:
> 

Yes, that works as well.

Feel free to add my Tested-by: if you want to take that patch.

Thanks,
Guenter

> diff --git a/arch/arm64/include/asm/irq_work.h b/arch/arm64/include/asm/irq_work.h
> index 8e24ef3f7c82..b4f6b19a8a68 100644
> --- a/arch/arm64/include/asm/irq_work.h
> +++ b/arch/arm64/include/asm/irq_work.h
> @@ -1,6 +1,8 @@
>  #ifndef __ASM_IRQ_WORK_H
>  #define __ASM_IRQ_WORK_H
>  
> +#ifdef CONFIG_SMP
> +
>  #include <asm/smp.h>
>  
>  static inline bool arch_irq_work_has_interrupt(void)
> @@ -8,4 +10,13 @@ static inline bool arch_irq_work_has_interrupt(void)
>  	return !!__smp_cross_call;
>  }
>  
> +#else
> +
> +static inline bool arch_irq_work_has_interrupt(void)
> +{
> +	return false;
> +}
> +
> +#endif
> +
>  #endif /* __ASM_IRQ_WORK_H */