Re: [PATCH] RISC-V: Issue a local tlb flush if possible.

[Andreas Schwab]

On Aug 09 2019, Atish Patra <atish.patra@xxxxxxx> wrote:

> @@ -46,14 +47,38 @@ static inline void remote_sfence_vma(struct cpumask *cmask, unsigned long start,
>  				     unsigned long size)
>  {
>  	struct cpumask hmask;
> +	struct cpumask tmask;
> +	int cpuid = smp_processor_id();
>  
>  	cpumask_clear(&hmask);
> -	riscv_cpuid_to_hartid_mask(cmask, &hmask);
> -	sbi_remote_sfence_vma(hmask.bits, start, size);
> +	cpumask_clear(&tmask);
> +
> +	if (cmask)
> +		cpumask_copy(&tmask, cmask);
> +	else
> +		cpumask_copy(&tmask, cpu_online_mask);
> +
> +	if (cpumask_test_cpu(cpuid, &tmask)) {
> +		/* Save trap cost by issuing a local tlb flush here */
> +		if ((start == 0 && size == -1) || (size > PAGE_SIZE))
> +			local_flush_tlb_all();
> +		else if (size == PAGE_SIZE)
> +			local_flush_tlb_page(start);
> +		cpumask_clear_cpu(cpuid, &tmask);
> +	} else if (cpumask_empty(&tmask)) {
> +		/* cpumask is empty. So just do a local flush */
> +		local_flush_tlb_all();
> +		return;
> +	}
> +
> +	if (!cpumask_empty(&tmask)) {
> +		riscv_cpuid_to_hartid_mask(&tmask, &hmask);
> +		sbi_remote_sfence_vma(hmask.bits, start, size);
> +	}
>  }

I think it's becoming too big to be inline.

Andreas.

-- 
Andreas Schwab, schwab@xxxxxxxxxxxxxx
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