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Message-ID: <248a41a536d5a3c9e81e8e865b34c5bf74cd36d4.camel@linux.ibm.com>
Subject: Re: [PATCH v4] Kconfig: introduce HAS_IOPORT option and select it
 as necessary
From:   Niklas Schnelle <schnelle@linux.ibm.com>
To:     Arnd Bergmann <arnd@arndb.de>,
        Richard Henderson <richard.henderson@linaro.org>,
        Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
        Matt Turner <mattst88@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Huacai Chen <chenhuacai@kernel.org>,
        WANG Xuerui <kernel@xen0n.name>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Michal Simek <monstr@monstr.eu>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
        Helge Deller <deller@gmx.de>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Nicholas Piggin <npiggin@gmail.com>,
        Christophe Leroy <christophe.leroy@csgroup.eu>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Yoshinori Sato <ysato@users.sourceforge.jp>,
        Rich Felker <dalias@libc.org>,
        John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
        "David S. Miller" <davem@davemloft.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Uwe =?ISO-8859-1?Q?Kleine-K=F6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Alan Stern <stern@rowland.harvard.edu>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
        linux-pci@vger.kernel.org, Arnd Bergmann <arnd@kernel.org>,
        Johannes Berg <johannes@sipsolutions.net>,
        linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-ia64@vger.kernel.org, loongarch@lists.linux.dev,
        linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org,
        linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org,
        sparclinux@vger.kernel.org
Date:   Wed, 05 Apr 2023 17:12:38 +0200
In-Reply-To: <20230323163354.1454196-1-schnelle@linux.ibm.com>
References: <20230323163354.1454196-1-schnelle@linux.ibm.com>
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On Thu, 2023-03-23 at 17:33 +0100, Niklas Schnelle wrote:
> We introduce a new HAS_IOPORT Kconfig option to indicate support for I/O
> Port access. In a future patch HAS_IOPORT=3Dn will disable compilation of
> the I/O accessor functions inb()/outb() and friends on architectures
> which can not meaningfully support legacy I/O spaces such as s390.
>=20
> The following architectures do not select HAS_IOPORT:
>=20
> * ARC
> * C-SKY
> * Hexagon
> * Nios II
> * OpenRISC
> * s390
> * User-Mode Linux
> * Xtensa
>=20
> All other architectures select HAS_IOPORT at least conditionally.
>=20
> The "depends on" relations on HAS_IOPORT in drivers as well as ifdefs
> for HAS_IOPORT specific sections will be added in subsequent patches on
> a per subsystem basis.
>=20
> Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> Acked-by: Johannes Berg <johannes@sipsolutions.net> # for ARCH=3Dum
> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---
> Note: This patch is the initial patch of a larger series[0]. This patch
> introduces the HAS_IOPORT config option while the rest of the series adds
> driver dependencies and the final patch removes inb() / outb() and friend=
s on
> platforms that don't support them.=20
>=20
> Thus each of the per-subsystem patches is independent from each other but
> depends on this patch while the final patch depends on the whole series. =
Thus
> splitting this initial patch off allows the per-subsytem HAS_IOPORT depen=
dency
> addition be merged separately via different trees without breaking the bu=
ild.
>=20
> [0] https://lore.kernel.org/lkml/20230314121216.413434-1-schnelle@linux.i=
bm.com/
>=20
> Changes since v3:
> - List archs without HAS_IOPORT in commit message (Arnd)
> - Select HAS_IOPORT for LoongArch (Arnd)
> - Use "select HAS_IOPORT if (E)ISA || .." instead of a "depends on" for (=
E)ISA
>   for m68k and parisc
> - Select HAS_IOPORT with config GSC on parisc (Arnd)
> - Drop "depends on HAS_IOPORT" for um's config ISA (Johannes)
> - Drop "depends on HAS_IOPORT" for config ISA on x86 and parisc where it =
is
>   always selected (Arnd)
>=20

Gentle ping. As far as I can tell this hasn't been picked to any tree
sp far but also hasn't seen complains so I'm wondering if I should send
a new version of the combined series of this patch plus the added
HAS_IOPORT dependencies per subsystem or wait until this is picked up.

Thanks,
Niklas