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Message-ID: <49ca1cd8-e9a4-a76f-abae-d6204691665f@huawei.com>
Date:   Tue, 24 May 2022 22:31:03 +0800
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Subject: Re: [PATCH v3 4/6] mm: ioremap: Add arch_ioremap/iounmap()
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To:     Arnd Bergmann <arnd@arndb.de>
CC:     kernel test robot <lkp@intel.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        <kbuild-all@lists.01.org>, Linux-MM <linux-mm@kvack.org>,
        Christoph Hellwig <hch@infradead.org>,
        "Anshuman Khandual" <anshuman.khandual@arm.com>
References: <20220519082552.117736-5-wangkefeng.wang@huawei.com>
 <202205240657.BXxrhbgp-lkp@intel.com>
 <c4ea8f50-f445-f4ee-1d17-f21954e52a83@huawei.com>
 <CAK8P3a1qEk3hLUOijtzXRhT4-nZO8KUe1a_3mvUVSSzaGt2itg@mail.gmail.com>
From:   Kefeng Wang <wangkefeng.wang@huawei.com>
In-Reply-To: <CAK8P3a1qEk3hLUOijtzXRhT4-nZO8KUe1a_3mvUVSSzaGt2itg@mail.gmail.com>
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On 2022/5/24 20:35, Arnd Bergmann wrote:
> On Tue, May 24, 2022 at 11:48 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
>>>>> mm/ioremap.c:59:16: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void const *addr @@     got void [noderef] __iomem *vaddr @@
>>>      mm/ioremap.c:59:16: sparse:     expected void const *addr
>>>      mm/ioremap.c:59:16: sparse:     got void [noderef] __iomem *vaddr
>>>
>>> vim +59 mm/ioremap.c
>>>
>>>       51
>>>       52       void iounmap(volatile void __iomem *addr)
>>>       53       {
>>>       54               void __iomem *vaddr = (void __iomem *)((unsigned long)addr & PAGE_MASK);
>>>       55
>>>       56               if (arch_iounmap(vaddr))
>>>       57                       return;
>>>       58
>>>     > 59               vunmap(vaddr);
>> 1) Will add generic "arch_ioremap/arch_iounmap define"
>>
>> 2) and change this to vunmap((void *)vaddr);
> I think this need an extra __force to actually suppress the sparse
> warning, as in
>
>          vunmap((void __force *)vaddr);
>
> Using __force is usually wrong, this is one of the exceptions, so
> maybe add a comment
> as well.
Right, I found this too， and  using  ___force in local, will update, thank.
>
>           Arnd
>
> .