Re: [PATCH v3 4/6] mm: ioremap: Add arch_ioremap/iounmap()

[Kefeng Wang <wangkefeng.wang@huawei.com>]

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
>
> .