Re: [PATCH v2] powerpc32: memcpy/memset: only use dcbz once cache is enabled

From: Scott Wood
Date: Thu Sep 10 2015 - 18:05:57 EST


On Thu, 2015-09-10 at 08:41 +0200, Christophe Leroy wrote:
>
> +/* Cache related sections */
> +#define BEGIN_CACHE_SECTION_NESTED(label) START_FTR_SECTION(label)
> +#define BEGIN_CACHE_SECTION START_FTR_SECTION(97)
> +
> +#define END_CACHE_SECTION_NESTED(msk, val, label) \
> + FTR_SECTION_ELSE_NESTED(label) \
> + MAKE_FTR_SECTION_ENTRY(msk, val, label, __cache_fixup)
> +
> +#define END_CACHE_SECTION(msk, val) \
> + END_CACHE_SECTION_NESTED(msk, val, 97)
> +
> +#define END_CACHE_SECTION_IFSET(msk) END_CACHE_SECTION((msk), (msk))
> +#define END_CACHE_SECTION_IFCLR(msk) END_CACHE_SECTION((msk), 0)
> +
> +/* CACHE feature sections with alternatives, use BEGIN_FTR_SECTION to
> start */
> +#define CACHE_SECTION_ELSE_NESTED(label) FTR_SECTION_ELSE_NESTED(label)
> +#define CACHE_SECTION_ELSE CACHE_SECTION_ELSE_NESTED(97)
> +#define ALT_CACHE_SECTION_END_NESTED(msk, val, label) \
> + MAKE_FTR_SECTION_ENTRY(msk, val, label, __cache_fixup)
> +#define ALT_CACHE_SECTION_END_NESTED_IFSET(msk, label) \
> + ALT_CACHE_SECTION_END_NESTED(msk, msk, label)
> +#define ALT_CACHE_SECTION_END_NESTED_IFCLR(msk, label) \
> + ALT_CACHE_SECTION_END_NESTED(msk, 0, label)
> +#define ALT_CACHE_SECTION_END(msk, val) \
> + ALT_CACHE_SECTION_END_NESTED(msk, val, 97)
> +#define ALT_CACHE_SECTION_END_IFSET(msk) \
> + ALT_CACHE_SECTION_END_NESTED_IFSET(msk, 97)
> +#define ALT_CACHE_SECTION_END_IFCLR(msk) \
> + ALT_CACHE_SECTION_END_NESTED_IFCLR(msk, 97)

I don't think this duplication is what Michael meant by "the normal cpu
feature sections". What else is going to use this very specific
infrastructure?

-Scott

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