On Tue, Jul 24, 2018 at 07:37:28PM -0700, Cannon Matthews wrote:
> diff --git a/arch/x86/lib/clear_page_64.S b/arch/x86/lib/clear_page_64.S
> index 88acd349911b..81a39804ac72 100644
> --- a/arch/x86/lib/clear_page_64.S
> +++ b/arch/x86/lib/clear_page_64.S
> @@ -49,3 +49,23 @@ ENTRY(clear_page_erms)
> ret
> ENDPROC(clear_page_erms)
> EXPORT_SYMBOL_GPL(clear_page_erms)
> +
> +/*
> + * Zero memory using non temporal stores, bypassing the cache.
> + * Requires an `sfence` (wmb()) afterwards.
> + * %rdi - destination.
> + * %rsi - page size. Must be 64 bit aligned.
> +*/
> +ENTRY(__clear_page_nt)
> + leaq (%rdi,%rsi), %rdx
> + xorl %eax, %eax
> + .p2align 4,,10
> + .p2align 3
> +.L2:
> + movnti %rax, (%rdi)
> + addq $8, %rdi
> + cmpq %rdx, %rdi
> + jne .L2
> + ret
> +ENDPROC(__clear_page_nt)
> +EXPORT_SYMBOL(__clear_page_nt)
EXPORT_SYMBOL_GPL like the other functions in that file.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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