Re: [PATCH v2 1/2] x86/UV: Introduce a helper function to check UV system at earlier stage

[Mike Travis]

Acked-by: Mike Travis <travis@xxxxxxx>

On 5/20/2017 5:02 AM, Baoquan He wrote:
> The SGI BIOS adds UVsystab, and only systems running SGI BIOS
> (and now HPE Hawks2) will have UVsystab. And UVsystab is detected in
> efi_init() which is at very early stage. So introduce a new helper
> function is_early_uv_system() for later usage.
>
> Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: Russ Anderson <rja@xxxxxxx>
> Cc: Dimitri Sivanich <sivanich@xxxxxxx>
> Cc: "travis@xxxxxxx" <travis@xxxxxxx>
> Cc: Mike Travis <mike.travis@xxxxxxx>
> Cc: Frank Ramsay <frank.ramsay@xxxxxxx>
> ---
>   arch/x86/include/asm/uv/uv.h | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h
> index 6686820..159f698 100644
> --- a/arch/x86/include/asm/uv/uv.h
> +++ b/arch/x86/include/asm/uv/uv.h
> @@ -19,6 +19,11 @@ extern const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
>   						 unsigned long start,
>   						 unsigned long end,
>   						 unsigned int cpu);
> +#include <linux/efi.h>
> +static inline int is_early_uv_system(void)
> +{
> +	return !((efi.uv_systab == EFI_INVALID_TABLE_ADDR) || !efi.uv_systab);
> +}
>   
>   #else	/* X86_UV */
>   
> @@ -31,6 +36,7 @@ static inline const struct cpumask *
>   uv_flush_tlb_others(const struct cpumask *cpumask, struct mm_struct *mm,
>   		    unsigned long start, unsigned long end, unsigned int cpu)
>   { return cpumask; }
> +static inline int is_early_uv_system(void)	{ return 0; }
>   
>   #endif	/* X86_UV */
>