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

[Kefeng Wang]

On 2022/5/20 2:52, Andrew Morton wrote:
> On Thu, 19 May 2022 16:25:50 +0800 Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
>
> > Add special hook for architecture to verify or setup addr, size
> > or prot when ioremap() or iounmap(), which will make the generic
> > ioremap more useful.
> >
> >    arch_ioremap() return a pointer,
> >      - IS_ERR means return an error
> >      - NULL means continue to remap
> >      - a non-NULL, non-IS_ERR pointer is directly returned
> >    arch_iounmap() return a int value,
> >      - 0 means continue to vunmap
> >      - error code means skip vunmap and return directly
> >
> > ...
> >
> > --- a/include/asm-generic/io.h
> > +++ b/include/asm-generic/io.h
> > @@ -964,6 +964,30 @@ static inline void iounmap(volatile void __iomem *addr)
> >   #elif defined(CONFIG_GENERIC_IOREMAP)
> >   #include <linux/pgtable.h>
> >   
> > +/*
> > + * Arch code can implement the following two special hooks when using GENERIC_IOREMAP
> > + * arch_ioremap() return a pointer,
> > + *   - IS_ERR means return an error
> > + *   - NULL means continue to remap
> > + *   - a non-NULL, non-IS_ERR pointer is returned directly
> > + * arch_iounmap() return a int,
> > + *   - 0 means continue to vunmap
> > + *   - error code means skip vunmap and return directly
> > + */
> > +#ifndef arch_ioremap
> > +static inline void __iomem *arch_ioremap(phys_addr_t phys_addr, size_t size, unsigned long prot)
> > +{
> > +	return NULL;
> > +}
> Maybe should do
>
> 	#define arch_ioremap arch_ioremap
>
> here
>
> > +#endif
> > +
> > +#ifndef arch_iounmap
> > +static inline int arch_iounmap(void __iomem *addr)
> > +{
> > +	return 0;
> > +}
> and here.
>
> It shouldn't matter a lot because this file has inclusion guards.
> However it seems tidier and perhaps other code will want to know
> whether this was defined.  Dunno.
Oh, forget to add the define part, thanks Andrew.

Hi Catalin, could you help to involve them when taking them, many thanks.

> Otherwise,
>
> Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>
> Please take this patch and [2/6] and [3/6] via the appropriate arm tree.
>
> .