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Date:   Fri, 28 Sep 2018 09:15:03 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Guo Ren <ren_guo@c-sky.com>
Cc:     akpm@linux-foundation.org, arnd@arndb.de,
        daniel.lezcano@linaro.org, davem@davemloft.net,
        gregkh@linuxfoundation.org, jason@lakedaemon.net,
        marc.zyngier@arm.com, mark.rutland@arm.com,
        mchehab+samsung@kernel.org, peterz@infradead.org, robh@kernel.org,
        robh+dt@kernel.org, tglx@linutronix.de,
        linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
        devicetree@vger.kernel.org, green.hu@gmail.com
Subject: Re: [PATCH V6 04/33] csky: Exception handling and mm-fault
Message-ID: <20180928161503.GC19827@infradead.org>
References: <cover.1538058840.git.ren_guo@c-sky.com>
 <a4571e227938b58d8ba5f35e2f8e17b625478607.1538058840.git.ren_guo@c-sky.com>
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> +#ifndef CONFIG_CPU_HAS_TLBI
> +	/*
> +	 * We fault-in kernel-space virtual memory on-demand. The
> +	 * 'reference' page table is init_mm.pgd.
> +	 *
> +	 * NOTE! We MUST NOT take any locks for this case. We may
> +	 * be in an interrupt or a critical region, and should
> +	 * only copy the information from the master page table,
> +	 * nothing more.
> +	 */
> +	if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
> +	{

This doesn't fir the kernel style.  Please run checkpatch.pl over
your code and fix at least all warnings that don't seem clearly bogus.