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Date:   Mon, 10 Oct 2022 08:17:02 +0800
From:   Baoquan He <bhe@redhat.com>
To:     Christophe Leroy <christophe.leroy@csgroup.eu>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "hch@infradead.org" <hch@infradead.org>,
        "agordeev@linux.ibm.com" <agordeev@linux.ibm.com>,
        "wangkefeng.wang@huawei.com" <wangkefeng.wang@huawei.com>,
        "schnelle@linux.ibm.com" <schnelle@linux.ibm.com>,
        "David.Laight@ACULAB.COM" <David.Laight@aculab.com>,
        "shorne@gmail.com" <shorne@gmail.com>,
        Brian Cain <bcain@quicinc.com>,
        Mark Brown <broonie@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        "linux-hexagon@vger.kernel.org" <linux-hexagon@vger.kernel.org>
Subject: Re: [PATCH v3 01/11] hexagon: mm: Convert to GENERIC_IOREMAP
Message-ID: <Y0NkfggJTI1q/Yvy@MiWiFi-R3L-srv>
References: <20221009103114.149036-1-bhe@redhat.com>
 <20221009103114.149036-2-bhe@redhat.com>
 <83f292b8-0639-56b2-6dac-0475c34f623c@csgroup.eu>
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On 10/09/22 at 04:39pm, Christophe Leroy wrote:
> 
> 
> Le 09/10/2022 ? 12:31, Baoquan He a ?crit?:
> > 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 iounmap(), and has the equivalent functioality.
> > 
> > For hexagon, the current ioremap() and iounmap() are the same as
> > generic version. After taking GENERIC_IOREMAP way, the old ioremap()
> > and iounmap() can be completely removed.
> > 
> > Signed-off-by: Baoquan He <bhe@redhat.com>
> > Cc: Brian Cain <bcain@quicinc.com>
> > Cc: Mark Brown <broonie@kernel.org>
> > Cc: Linus Walleij <linus.walleij@linaro.org>
> > Cc: linux-hexagon@vger.kernel.org
> > ---
> > v2->v3:
> >    Rewrite patch log.
> >    Put it at the beginning of patchset since it doesn't introduce new
> >    arch_ioremap()/arch_iounmap().
> > 
> >   arch/hexagon/Kconfig          |  1 +
> >   arch/hexagon/include/asm/io.h |  9 +++++--
> >   arch/hexagon/mm/ioremap.c     | 44 -----------------------------------
> >   3 files changed, 8 insertions(+), 46 deletions(-)
> >   delete mode 100644 arch/hexagon/mm/ioremap.c
> > 
> > diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
> > index 54eadf265178..17afffde1a7f 100644
> > --- a/arch/hexagon/Kconfig
> > +++ b/arch/hexagon/Kconfig
> > @@ -25,6 +25,7 @@ config HEXAGON
> >   	select NEED_SG_DMA_LENGTH
> >   	select NO_IOPORT_MAP
> >   	select GENERIC_IOMAP
> > +	select GENERIC_IOREMAP
> >   	select GENERIC_SMP_IDLE_THREAD
> >   	select STACKTRACE_SUPPORT
> >   	select GENERIC_CLOCKEVENTS_BROADCAST
> > diff --git a/arch/hexagon/include/asm/io.h b/arch/hexagon/include/asm/io.h
> > index 46a099de85b7..dcd9cbbf5934 100644
> > --- a/arch/hexagon/include/asm/io.h
> > +++ b/arch/hexagon/include/asm/io.h
> > @@ -170,8 +170,13 @@ static inline void writel(u32 data, volatile void __iomem *addr)
> >   #define writew_relaxed __raw_writew
> >   #define writel_relaxed __raw_writel
> >   
> > -void __iomem *ioremap(unsigned long phys_addr, unsigned long size);
> > -#define ioremap_uc(X, Y) ioremap((X), (Y))
> > +/*
> > + * I/O memory mapping functions.
> > + */
> > +#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
> > +		       (__HEXAGON_C_DEV << 6))
> > +
> > +#define ioremap_uc(addr, size) ioremap((addr), (size))
> 
> Why do you need to change this macro ?

I don't like the X, Y since they look meaningless. I can change back if
you like the old one. Thanks for checking.