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From:   Andreas Schwab <schwab@linux-m68k.org>
To:     Atish Patra <Atish.Patra@wdc.com>
Cc:     "linux-riscv\@lists.infradead.org" <linux-riscv@lists.infradead.org>,
        "paul.walmsley\@sifive.com" <paul.walmsley@sifive.com>,
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        "allison\@lohutok.net" <allison@lohutok.net>,
        "anup\@brainfault.org" <anup@brainfault.org>,
        "linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "hch\@infradead.org" <hch@infradead.org>,
        "palmer\@sifive.com" <palmer@sifive.com>
Subject: Re: [v2 PATCH] RISC-V: Optimize tlb flush path.
References: <20190820004735.18518-1-atish.patra@wdc.com>
        <mvmh86cl1o3.fsf@linux-m68k.org>
        <b2510462b55ffd93dba0c1b7cc28f9eef3089b50.camel@wdc.com>
Date:   Tue, 20 Aug 2019 10:51:07 +0200
In-Reply-To: <b2510462b55ffd93dba0c1b7cc28f9eef3089b50.camel@wdc.com> (Atish
        Patra's message of "Tue, 20 Aug 2019 08:42:19 +0000")
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On Aug 20 2019, Atish Patra <Atish.Patra@wdc.com> wrote:

> +
> +       cpuid = get_cpu();
> +	if (!cmask) {
> +               riscv_cpuid_to_hartid_mask(cpu_online_mask, &hmask);
> +               goto issue_sfence;
> +       }
> +
> +       
> +       if (cpumask_test_cpu(cpuid, cmask) && cpumask_weight(cmask) ==
> 1) {
> +               /* 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);
> +               goto done;
> +       }
> +
>         riscv_cpuid_to_hartid_mask(cmask, &hmask);
> +
> +issue_sfence:
>         sbi_remote_sfence_vma(hmask.bits, start, size);
> +done:
> +       put_cpu();
>  }
>
> This is much simpler than what I had done in v2. I will address the if
> condition around size as well.

I still think that this function should be moved out of the header.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."