[PATCH 2/4] mm: ioremap: Add arch_ioremap/iounmap_check()

[Andrew Morton]

On Wed, 27 Apr 2022 20:14:11 +0800 Kefeng Wang <wangkefeng.wang at huawei.com> wrote:

> Add special check hook for architecture to verify addr, size
> or prot when ioremap() or iounmap(), which will make the generic
> ioremap more useful.
> 
> ...
>
> --- a/include/asm-generic/io.h
> +++ b/include/asm-generic/io.h
> @@ -964,6 +964,9 @@ static inline void iounmap(volatile void __iomem *addr)
>  #elif defined(CONFIG_GENERIC_IOREMAP)
>  #include <linux/pgtable.h>
>  
> +bool arch_ioremap_check(phys_addr_t addr, size_t size, unsigned long prot);
> +bool arch_iounmap_check(void __iomem *addr);

Pet peeve.  The word "check" is a poor one.  I gives no sense of what
the function is checking and it gives no sense of how the function's
return value relates to the thing which it checks.

Maybe it returns 0 on success and -EINVAL on failure.  Don't know!

Don't you think that better names would be io_remap_ok(),
io_remap_valid(), io_remap_allowed(), etc?


Other than that, 

Acked-by: Andrew Morton <akpm at linux-foundation.org>