Date:   Thu, 9 Mar 2023 08:43:38 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Huacai Chen <chenhuacai@kernel.org>
Cc:     Xi Ruoyao <xry111@xry111.site>, WANG Xuerui <kernel@xen0n.name>,
        Huacai Chen <chenhuacai@loongson.cn>,
        Arnd Bergmann <arnd@arndb.de>, loongarch@lists.linux.dev,
        linux-arch@vger.kernel.org, Xuefeng Li <lixuefeng@loongson.cn>,
        Guo Ren <guoren@kernel.org>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn
Subject: Re: [PATCH] LoongArch: Provide kernel fpu functions
Message-ID: <ZAoMunXRR+kM7thg@infradead.org>
References: <20230305052818.4030447-1-chenhuacai@loongson.cn>
 <48f508aa-ab40-7032-a68d-90d8986afb2f@xen0n.name>
 <CAAhV-H55QUrkYYR1Lbj=zbquiz3frX2dNAH23fAuN6eCOUddNA@mail.gmail.com>
 <58cc7e6d19628757d6d8dc192d07876288f6077e.camel@xry111.site>
 <CAAhV-H7vv+AE-7kDf7YpU6_f_dTNxKKoRSHC6vA4aBHOVyMRAQ@mail.gmail.com>
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On Mon, Mar 06, 2023 at 09:55:27AM +0800, Huacai Chen wrote:
> On Sun, Mar 5, 2023 at 9:28 PM Xi Ruoyao <xry111@xry111.site> wrote:
> >
> > On Sun, 2023-03-05 at 20:18 +0800, Huacai Chen wrote:
> > > > Might be good to provide some explanation in the commit message as to
> > > > why the pair of helpers should be GPL-only. Do they touch state buried
> > > > deep enough to make any downstream user a "derivative work"? Or are the
> > > > annotation inspired by arch/x86?
> > > Yes, just inspired by arch/x86, and I don't think these symbols should
> > > be used by non-GPL modules.
> >
> > Hmm, what if one of your partners wish to provide a proprietary GPU
> > driver using the FPU like this way?  As a FLOSS developer I'd say "don't
> > do that, make your driver GPL".  But for Loongson there may be a
> > commercial issue.
> So use EXPORT_SYMBOL can make life easier?

No.  All in-kernel FPU helpers must be EXPORT_SYMBOL_GPL.