Re: [PATCH] ARM: fix XIP_KERNEL dependencies

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Arnd Bergmann <arnd@kernel.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Ard Biesheuvel <ardb@kernel.org>, Sekhar Nori <nsekhar@ti.com>,
	Bartosz Golaszewski <brgl@bgdev.pl>,
	Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Pengutronix Kernel Team <kernel@pengutronix.de>,
	Andrew Lunn <andrew@lunn.ch>,
	Gregory Clement <gregory.clement@bootlin.com>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Subject: Re: [PATCH] ARM: fix XIP_KERNEL dependencies
Date: Tue, 30 Aug 2022 09:41:39 +0200	[thread overview]
Message-ID: <CAMuHMdXqzOTDkbC7NXXQ32dLfO+JfkEMijxepEA=FfThSE9Xow@mail.gmail.com> (raw)
In-Reply-To: <63a630b7-9068-40f9-b7f7-d9a08f74ed13@www.fastmail.com>

Hi Arnd,

On Tue, Aug 30, 2022 at 9:21 AM Arnd Bergmann <arnd@arndb.de> wrote:
> CONFIG_XIP_KERNEL does not work with any option that involves patching
> the read-only kernel .text.
>
> Since at least CONFIG_SMP_ON_UP is required in certain configurations,
> flip the dependency to always allow the .text patching options but make
> XIP_KERNEL have the dependency instead.
>
> This is a prerequisite for allowing CONFIG_ARCH_MULTIPLATFORM to
> be disabled.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks for your patch!

> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1619,6 +1619,7 @@ endchoice
>  config XIP_KERNEL
>         bool "Kernel Execute-In-Place from ROM"
>         depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
> +       depends on !SMP_ON_UP && !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT

You may want to keep the list sorted.

>         help
>           Execute-In-Place allows the kernel to run from non-volatile storage
>           directly addressable by the CPU, such as NOR flash. This saves RAM

Regardless, LGTM, so
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds