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Date: Fri, 10 Jan 2025 11:41:47 +0100
From: Danilo Krummrich <dakr@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
	Abdiel Janulgue <abdiel.janulgue@gmail.com>,
	daniel.almeida@collabora.com, aliceryhl@google.com,
	robin.murphy@arm.com, rust-for-linux@vger.kernel.org,
	Miguel Ojeda <ojeda@kernel.org>,
	Alex Gaynor <alex.gaynor@gmail.com>,
	Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
	=?iso-8859-1?Q?Bj=F6rn?= Roy Baron <bjorn3_gh@protonmail.com>,
	Benno Lossin <benno.lossin@proton.me>,
	Andreas Hindborg <a.hindborg@kernel.org>,
	Trevor Gross <tmgross@umich.edu>,
	Valentin Obst <kernel@valentinobst.de>,
	open list <linux-kernel@vger.kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>, airlied@redhat.com,
	"open list:DMA MAPPING HELPERS" <iommu@lists.linux.dev>,
	Greg KH <gregkh@linuxfoundation.org>
Subject: Re: [PATCH v8 2/2] rust: add dma coherent allocator abstraction.
Message-ID: <Z4D5a5NYrAbNxUL6@pollux>
References: <20250108122825.136021-1-abdiel.janulgue@gmail.com>
 <20250108122825.136021-3-abdiel.janulgue@gmail.com>
 <20250108135951.GA18074@lst.de>
 <CANiq72=R2N+QiCiHZQu-6YJ9aYpn_bik3BW3U=nAW3jL7unzLw@mail.gmail.com>
 <20250108151858.GB24499@lst.de>
 <Z36X_ZnCmBQBMoZ6@pollux>
 <20250109080812.GA20431@lst.de>
 <Z3-NqwAG_96yq8VD@pollux>
 <20250110083955.GA5395@lst.de>
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In-Reply-To: <20250110083955.GA5395@lst.de>

On Fri, Jan 10, 2025 at 09:39:55AM +0100, Christoph Hellwig wrote:
> On Thu, Jan 09, 2025 at 09:49:47AM +0100, Danilo Krummrich wrote:
> > On Thu, Jan 09, 2025 at 09:08:12AM +0100, Christoph Hellwig wrote:
> > > On Wed, Jan 08, 2025 at 04:21:33PM +0100, Danilo Krummrich wrote:
> > > > What does "your code" mean? Duplicated in every driver?
> > > 
> > > Yes, interfaces to the DMA API should stay in readable C code and not
> > > in weird bindings so that it reminds greppable and maintainable.
> > > 
> > 
> > Rust drivers shouldn't use C APIs directly, but rather use an abstraction of the
> > corresponding C API.
> 
> Don't force me to deal with your shiny language of the day.

Again, no one asks you to deal with or maintain this piece of Rust code.

> Maintaining
> multi-language projects is a pain I have no interest in dealing with.
> If you want to use something that's not C, be that assembly or rust you
> write to C interfaces and deal with the impedence mismatch yourself as
> far as I'm concerned.
> 

This is exactly what we're doing and proposing here, isn't it?

We wrote a single piece of Rust code that abstracts the C API for all Rust
drivers, which we offer to maintain ourselves.

What else are you asking for?