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Date:   Sun, 28 Aug 2022 23:08:16 +0800
From:   Baoquan He <bhe@redhat.com>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        akpm@linux-foundation.org, agordeev@linux.ibm.com,
        wangkefeng.wang@huawei.com, linux-arm-kernel@lists.infradead.org,
        Brian Cain <bcain@quicinc.com>, linux-hexagon@vger.kernel.org
Subject: Re: [PATCH v2 05/11] hexagon: mm: Convert to GENERIC_IOREMAP
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References: <20220820003125.353570-1-bhe@redhat.com>
 <20220820003125.353570-6-bhe@redhat.com>
 <YwHX98KBEnZw9t6e@infradead.org>
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On 08/21/22 at 12:00am, Christoph Hellwig wrote:
> On Sat, Aug 20, 2022 at 08:31:19AM +0800, Baoquan He wrote:
> > With it, the old ioremap() and iounmap() can be perfectly removed
> > since they are duplicated with the standard functions.
> 
> Can you write a somewhat better commit message explaining that it
> switches to the generic code that has equivalent functionality?

OK, I will rephrase like below. Please check if it's OK.
==
By taking GENERIC_IOREMAP method, the generic ioremap_prot() and
iounmap() are visible and available to arch. Arch only needs to
provide implementation of arch_ioremap() or arch_iounmap() if there's
arch specific handling needed in its ioremap() or iounmap(). This
change will simplify implementation by removing duplicated codes with
generic ioremap() and iounma(), and has the equivalent functioality
as before.

> 
> > +#define ioremap_uc(addr, size) ioremap((addr), (size))
> 
> This is wrong and hexagon should use the asm-generic version of
> ioremap_uc that returns NULL.

I don't follow. Do you mean the function verion, but not a macro? Or
define it like below?

#define ioremap_uc(addr, size)  \
        ioremap_prot((addr), (size), _PAGE_IOREMAP)