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Date:   Tue, 1 Oct 2019 00:02:36 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Atish Patra <atish.patra@wdc.com>
Cc:     linux-kernel@vger.kernel.org, Albert Ou <aou@eecs.berkeley.edu>,
        Anup Patel <anup@brainfault.org>,
        Palmer Dabbelt <palmer@sifive.com>,
        Johan Hovold <johan@kernel.org>, hch@infradead.org,
        Paul Walmsley <paul.walmsley@sifive.com>,
        linux-riscv@lists.infradead.org
Subject: Re: [v6 PATCH] RISC-V: Remove unsupported isa string info print
Message-ID: <20191001070236.GA7622@infradead.org>
References: <20191001002318.7515-1-atish.patra@wdc.com>
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On Mon, Sep 30, 2019 at 05:23:18PM -0700, Atish Patra wrote:
> /proc/cpuinfo should just print all the isa string as an information
> instead of determining what is supported or not. ELF hwcap can be
> used by the userspace to figure out that.
> 
> Simplify the isa string printing by removing the unsupported isa string
> print and all related code.
> 
> The relevant discussion can be found at
> http://lists.infradead.org/pipermail/linux-riscv/2019-September/006702.html

This looks good, but can you also rename the orig_isa argument to isa
now that we never modify it?

>  	/*
>  	 * Linux doesn't support rv32e or rv128i, and we only support booting
>  	 * kernels on harts with the same ISA that the kernel is compiled for.
>  	 */
>  #if defined(CONFIG_32BIT)
> -	if (strncmp(isa, "rv32i", 5) != 0)
> +	if (strncmp(orig_isa, "rv32i", 5) != 0)
>  		return;
>  #elif defined(CONFIG_64BIT)
> -	if (strncmp(isa, "rv64i", 5) != 0)
> +	if (strncmp(orig_isa, "rv64i", 5) != 0)
>  		return;
>  #endif

And I don't think having these checks here makes much sense.  If we want
to check this at all we should do it somewhere in the boot process.