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Date:   Thu, 12 Oct 2023 17:34:56 +0200
From:   Thomas Bogendoerfer <tsbogend@alpha.franken.de>
To:     Gregory CLEMENT <gregory.clement@bootlin.com>
Cc:     Paul Burton <paulburton@kernel.org>, linux-mips@vger.kernel.org,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Vladimir Kondratiev <vladimir.kondratiev@intel.com>,
        Tawfik Bayouk <tawfik.bayouk@mobileye.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        =?iso-8859-1?Q?Th=E9o?= Lebrun <theo.lebrun@bootlin.com>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH 02/11] MIPS: use virtual addresses from xkphys for MIPS64
Message-ID: <ZSgSIPxrnx2FmHsk@alpha.franken.de>
References: <20231004161038.2818327-1-gregory.clement@bootlin.com>
 <20231004161038.2818327-3-gregory.clement@bootlin.com>
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On Wed, Oct 04, 2023 at 06:10:29PM +0200, Gregory CLEMENT wrote:
> From: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
> 
> Now 64-bit MIPS uses 32-bit compatible segments KSEG0 and KSEG1
> to trivially map first 1/2 GByte of physical memory. This memory
> used to run kernel. This mean, one should have memory installed
> in this area in order for Linux to work.
> 
> Kconfig CONFIG_USE_XKPHYS introduced; it adds support for kernel
> to use virtual addresses from the XKPHYS segment for both cached
> and uncached access. XKPHYS allows to access 2^48 bytes of
> memory, thus allowing kernel to work with any memory
> configuration.

IMHO it doesn't make sense to introduce an option for a generic
kernel, which then renders the generic kernel useless on all
platforms other then yours.

Please don't use generic, but setup a new platform for it. Hopefully
we can get rid all of the weirdness in this patch.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]