RE: [PATCH v2 07/11] powerpc/8xx: macro for handling CPU15 errata

From: David Laight
Date: Tue Jan 20 2015 - 06:10:07 EST


From Christophe Leroy
> Having a macro will help keep clear code.

It might remove an #if but it doesn't really help.
All it means is that anyone reading the code has to hunt for
the definition before proceeding.

Some comment about what (and why) the extra code is needed
might help.

...
> +
> +#ifdef CONFIG_8xx_CPU15
> +#define DO_8xx_CPU15(tmp, addr) \
> + addi tmp, addr, PAGE_SIZE; \
> + tlbie tmp; \
> + addi tmp, addr, PAGE_SIZE; \

You've even transcribed this incorrectly.

Clearly not tested :-)

David

> + tlbie tmp
> +#else
> +#define DO_8xx_CPU15(tmp, addr)
> +#endif
> +
> InstructionTLBMiss:
> #ifdef CONFIG_8xx_CPU6
> mtspr SPRN_DAR, r3
> @@ -304,12 +315,7 @@ InstructionTLBMiss:
> EXCEPTION_PROLOG_0
> mtspr SPRN_SPRG_SCRATCH2, r10
> mfspr r10, SPRN_SRR0 /* Get effective address of fault */
> -#ifdef CONFIG_8xx_CPU15
> - addi r11, r10, PAGE_SIZE
> - tlbie r11
> - addi r11, r10, -PAGE_SIZE
> - tlbie r11
> -#endif
> + DO_8xx_CPU15(r11, r10)
>
> /* If we are faulting a kernel address, we have to use the
> * kernel page tables.
> --
> 2.1.0
>
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