Re: [PATCH] powerpc/time: Fix build failure due to do_hard_irq_enable() on PPC32

[Nicholas Piggin <npiggin@gmail.com>]

Excerpts from Christophe Leroy's message of January 11, 2022 1:29 am:
> 	  CC      arch/powerpc/kernel/time.o
> 	In file included from <command-line>:
> 	./arch/powerpc/include/asm/hw_irq.h: In function 'do_hard_irq_enable':
> 	././include/linux/compiler_types.h:335:45: error: call to '__compiletime_assert_35' declared with attribute error: BUILD_BUG failed
> 	  335 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> 	      |                                             ^
> 	././include/linux/compiler_types.h:316:25: note: in definition of macro '__compiletime_assert'
> 	  316 |                         prefix ## suffix();                             \
> 	      |                         ^~~~~~
> 	././include/linux/compiler_types.h:335:9: note: in expansion of macro '_compiletime_assert'
> 	  335 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
> 	      |         ^~~~~~~~~~~~~~~~~~~
> 	./include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
> 	   39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
> 	      |                                     ^~~~~~~~~~~~~~~~~~
> 	./include/linux/build_bug.h:59:21: note: in expansion of macro 'BUILD_BUG_ON_MSG'
> 	   59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
> 	      |                     ^~~~~~~~~~~~~~~~
> 	./arch/powerpc/include/asm/hw_irq.h:483:9: note: in expansion of macro 'BUILD_BUG'
> 	  483 |         BUILD_BUG();
> 	      |         ^~~~~~~~~
> 
> should_hard_irq_enable() returns false on PPC32 so this BUILD_BUG() shouldn't trigger.
> 
> Force inlining of should_hard_irq_enable()
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> Fixes: 0faf20a1ad16 ("powerpc/64s/interrupt: Don't enable MSR[EE] in irq handlers unless perf is in use")
> Cc: Nicholas Piggin <npiggin@gmail.com>

Acked-by: Nicholas Piggin <npiggin@gmail.com>

Thanks,
Nick

> ---
>  arch/powerpc/include/asm/hw_irq.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
> index a58fb4aa6c81..674e5aaafcbd 100644
> --- a/arch/powerpc/include/asm/hw_irq.h
> +++ b/arch/powerpc/include/asm/hw_irq.h
> @@ -473,7 +473,7 @@ static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
>  	return !(regs->msr & MSR_EE);
>  }
>  
> -static inline bool should_hard_irq_enable(void)
> +static __always_inline bool should_hard_irq_enable(void)
>  {
>  	return false;
>  }
> -- 
> 2.33.1
>