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Date:   Tue, 16 May 2023 23:36:23 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Baoquan He <bhe@redhat.com>
Cc:     linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
        linux-mm@kvack.org, arnd@arndb.de, christophe.leroy@csgroup.eu,
        hch@infradead.org, agordeev@linux.ibm.com,
        wangkefeng.wang@huawei.com, schnelle@linux.ibm.com,
        David.Laight@aculab.com, shorne@gmail.com, willy@infradead.org,
        deller@gmx.de, Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>, linux-s390@vger.kernel.org
Subject: Re: [PATCH v5 RESEND 10/17] s390: mm: Convert to GENERIC_IOREMAP
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References: <20230515090848.833045-1-bhe@redhat.com>
 <20230515090848.833045-11-bhe@redhat.com>
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On Mon, May 15, 2023 at 05:08:41PM +0800, Baoquan He wrote:
> +#define ioremap_wc(addr, size)  \
> +	ioremap_prot((addr), (size), pgprot_val(pgprot_writecombine(PAGE_KERNEL)))

I'd move this out of line and just apply mio_wb_bit_mask directly
instead of the unbox/box/unbox/box dance.

> +#define ioremap_wt(addr, size)  \
> +	ioremap_prot((addr), (size), pgprot_val(pgprot_writethrough(PAGE_KERNEL)))

and just define this to ioremap_wc.  Note that defining _wt to _wc is
very odd and seems wrong, but comes from the existing code.  Maybe the
s390 maintainers can chime on on the background and we can add a comment
while we're at it.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>