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From:   Anup Patel <anup@brainfault.org>
Date:   Mon, 15 Apr 2019 12:59:31 +0530
Message-ID: <CAAhSdy36A9-A4YiGuQptzbUL-VVnfJtRU_5jfC+nD4-fq+M8-Q@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] RISC-V: Add separate asm/encoding.h for spec
 related defines
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Anup Patel <Anup.Patel@wdc.com>, Albert Ou <aou@eecs.berkeley.edu>,
        Palmer Dabbelt <palmer@sifive.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Atish Patra <Atish.Patra@wdc.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        "linux-riscv@lists.infradead.org" <linux-riscv@lists.infradead.org>
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On Mon, Apr 15, 2019 at 11:19 AM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Sat, Apr 13, 2019 at 03:38:35PM +0000, Anup Patel wrote:
> > It's better to have all RISC-V spec related defines in one place
> > so this patch adds separate asm/encoding.h for such defines which
> > can be included in assembly as well as C code.
>
> As per the discussion of version 1 on Saturday I disagree with this
> move.  There is both a philosophical and a practical reason for that:
>
>  a) in RISC-V CSR access is really nicely split out into a separate
>     number space, just accessed through a few special instructions.
>     It has no overlap with the rest of instruction encoding
>  b) <asm/csr.h> is pulled into just about every file build in the kernel
>     though <asm/irqflags.h>, <asm/switch_to.h> and <asm/thread_info.h>
>
> So even if you want to later add a new <asm/encoding.h> for instruction
> encoding details later, I'd rather prefer to keep CSR access separate
> from it.

Sure, no problem. I will add asm/encoding.h for instructions later.

Regards,
Anup