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[2003:df:bf2d:e300:336:adaa:8f43:9ca5]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4804db7b434sm26650055e9.4.2026.01.23.08.39.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 23 Jan 2026 08:39:50 -0800 (PST) Message-ID: <70412586-7b40-4230-bc21-504a865e3376@gmail.com> Date: Fri, 23 Jan 2026 17:39:48 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] rust: dma: allow drivers to tune max segment size To: Beata Michalska , dakr@kernel.org, ojeda@kernel.org, rust-for-linux@vger.kernel.org Cc: abdiel.janulgue@gmail.com, daniel.almeida@collabora.com, aliceryhl@google.com, robin.murphy@arm.com, a.hindborg@kernel.org, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, tmgross@umich.edu, linux-kernel@vger.kernel.org References: <20260123131308.3218421-1-beata.michalska@arm.com> Content-Language: de-AT-frami, en-US From: Dirk Behme In-Reply-To: <20260123131308.3218421-1-beata.michalska@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 23.01.26 14:13, Beata Michalska wrote: > Make dma_set_max_seg_size() available to Rust so drivers can perform > standard DMA setup steps. > > Signed-off-by: Beata Michalska > --- > > v2: > - Aligned safety requirements > > rust/helpers/dma.c | 5 +++++ > rust/kernel/dma.rs | 17 +++++++++++++++++ > 2 files changed, 22 insertions(+) > > diff --git a/rust/helpers/dma.c b/rust/helpers/dma.c > index 2afa32c21c94..220b9308830f 100644 > --- a/rust/helpers/dma.c > +++ b/rust/helpers/dma.c > @@ -40,3 +40,8 @@ size_t rust_helper_dma_max_mapping_size(struct device *dev) > { > return dma_max_mapping_size(dev); > } > + > +void rust_helper_dma_set_max_seg_size(struct device *dev, unsigned int size) > +{ > + dma_set_max_seg_size(dev, size); > +} I was about to ask "please add __rust_helper" [1]. But looking into driver-core-next it looks like some of the function in dma.c have __rust_helper (from [1]) and some don't (from [2]). Is this by intention or was this an omission in [2]? Best regards Dirk [1] https://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git/commit/rust/helpers/dma.c?h=driver-core-next&id=8a03afe94763108537e33b48378bbc7472b4cc9d [2] https://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git/commit/rust/helpers/dma.c?h=driver-core-next&id=d8932355f8c5673106eca49abd142f8fe0c1fe8b