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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 28 Apr 2022 08:47:19 +0200
Message-ID: <CAK8P3a3=A1Ow2WoyW9_i6nTr85M11N85OkW-ShX5fU-zX+F2aA@mail.gmail.com>
Subject: Re: [PATCH 2/4] mm: ioremap: Add arch_ioremap/iounmap_check()
To:     Kefeng Wang <wangkefeng.wang@huawei.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        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>,
        Linux-MM <linux-mm@kvack.org>
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On Thu, Apr 28, 2022 at 8:20 AM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> On 2022/4/28 2:20, Arnd Bergmann wrote:
> > On Wed, Apr 27, 2022 at 2:14 PM Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> >
> > bool arch_ioremap_check(phys_addr_t addr, size_t size, unsigned long prot);
> > #define arch_ioremap_check arch_ioremap_check
> Ok, I could use this way, and keep consistent with others definitions in
> asm/io.h
> > (or alternatively an extern declaration, if the implementation is nontrivial)
> >
> > It may be worth pointing out that either way requires including
> > asm-generic/io.h,
> > which most architectures don't. This is probably fine, as only csky, riscv and
> > now arm64 use CONFIG_GENERIC_IOREMAP, and we can probably require
> > that any further architectures using this symbol also have to use
> > asm-generic/io.h.
>
> It looks the arch is already include it,
>
> $ git grep "asm-generic/io.h" arch/
>
> arch/arc/include/asm/io.h:#include <asm-generic/io.h>
> arch/arm/include/asm/io.h:#include <asm-generic/io.h>
> arch/arm64/include/asm/io.h:#include <asm-generic/io.h>
> arch/csky/include/asm/io.h:#include <asm-generic/io.h>
> arch/h8300/include/asm/io.h:#include <asm-generic/io.h>
> arch/ia64/include/asm/io.h:#include <asm-generic/io.h>
> arch/m68k/include/asm/io.h:#include <asm-generic/io.h>
> arch/m68k/include/asm/io_no.h: * that behavior here first before we
> include asm-generic/io.h.
> arch/microblaze/include/asm/io.h:#include <asm-generic/io.h>
> arch/nios2/include/asm/io.h:#include <asm-generic/io.h>
> arch/openrisc/include/asm/io.h:#include <asm-generic/io.h>
> arch/powerpc/include/asm/io.h:#include <asm-generic/io.h>
> arch/riscv/include/asm/io.h:#include <asm-generic/io.h>
> arch/s390/include/asm/io.h:#include <asm-generic/io.h>
> arch/sparc/include/asm/io_32.h:#include <asm-generic/io.h>
> arch/um/include/asm/io.h:#include <asm-generic/io.h>
> arch/x86/include/asm/io.h:#include <asm-generic/io.h>
> arch/xtensa/include/asm/io.h:#include <asm-generic/io.h>

Right, it's mostly the older architectures that never started using
asm-generic/io.h:

$ git grep -L asm-generic/io.h arch/*/include/asm/io.h
arch/alpha/include/asm/io.h
arch/hexagon/include/asm/io.h
arch/mips/include/asm/io.h
arch/parisc/include/asm/io.h
arch/sh/include/asm/io.h
arch/sparc/include/asm/io.h # it is used on sparc32

That's actually less than I expected, and most of these are not
seeing a lot of upstream work any more.

        Arnd