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Date:   Thu, 06 Oct 2022 20:50:00 -0700 (PDT)
Subject:     Re: [PATCH v2 1/4] RISC-V: Fix ioremap_cache() and ioremap_wc() for systems with Svpbmt
In-Reply-To: <YzQ6pqykLhJVeD2p@infradead.org>
CC:     apatel@ventanamicro.com, Paul Walmsley <paul.walmsley@sifive.com>,
        atishp@atishpatra.org, heiko@sntech.de, anup@brainfault.org,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        mchitale@ventanamicro.com
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     Christoph Hellwig <hch@infradead.org>
Message-ID: <mhng-96bfb7a5-6579-4ebc-9517-db2e62d2f82b@palmer-ri-x1c9>
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On Wed, 28 Sep 2022 05:14:30 PDT (-0700), Christoph Hellwig wrote:
> On Thu, Sep 22, 2022 at 09:35:56AM -0700, Palmer Dabbelt wrote:
>> Sorry I missed this, I thought it was just part of the rest of this patch
>> set.  That said, I'm not actually sure this is a critical fix: sure it's a
>> performance problem, and if some driver is expecting ioremap_cache() to go
>> fast then possibly a pretty big one, but the only Svpmbt hardware that
>
> More importantly nothing should be using ioremap_cache at all.  It is
> an API that has long been deprecated in favor of memremap.

There's a few uses of it, I just send along a patch to make it 
arch-specific and make the users depend on it.  That should let us stop 
adding this to ports just to get the drivers building.