Subject: Re: [PATCH] powerpc/32s: Don't flush all TLBs when flushing one page

From: Segher Boessenkool <[email-masked]>
Date: Fri, 31 Jan 2020 09:51:50 -0600

On Fri, Jan 31, 2020 at 03:37:34PM +0000, Christophe Leroy wrote:
> When the range is a single page, do a page flush instead.

> +	start &= PAGE_MASK;
> +	end = (end - 1) | ~PAGE_MASK;
>  	if (!Hash) {
> -		_tlbia();
> +		if (end - start == PAGE_SIZE)
> +			_tlbie(start);
> +		else
> +			_tlbia();
>  		return;
>  	}

For just one page, you get  end - start == 0  actually?

Segher