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

From: Andrew Morton <akpm@linux-foundation.org>
To: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>
Subject: Re: [PATCH 2/4] mm: ioremap: Add arch_ioremap/iounmap_check()
Date: Wed, 27 Apr 2022 10:04:11 -0700	[thread overview]
Message-ID: <20220427100411.8eaf54c51767c3e2b0b070a5@linux-foundation.org> (raw)
In-Reply-To: <20220427121413.168468-3-wangkefeng.wang@huawei.com>

On Wed, 27 Apr 2022 20:14:11 +0800 Kefeng Wang <wangkefeng.wang@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@linux-foundation.org>