Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
rust: dma: allow drivers to tune max segment size
Make dma_set_max_seg_size() available to Rust so drivers can perform
standard DMA setup steps.
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
Acked-by: Robin Murphy <robvin.murphy@arm.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260128135320.689046-1-beata.michalska@arm.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
authored by
Beata Michalska
and committed by
Danilo Krummrich
c7125739
7c60d964
+23
+6
rust/helpers/dma.c
+6
rust/helpers/dma.c
+17
rust/kernel/dma.rs
+17
rust/kernel/dma.rs
···
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bindings::dma_set_mask_and_coherent(self.as_ref().as_raw(), mask.value())
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})
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}
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+
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/// Set the maximum size of a single DMA segment the device may request.
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///
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/// This method is usually called once from `probe()` as soon as the device capabilities are
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/// known.
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///
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/// # Safety
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///
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/// This method must not be called concurrently with any DMA allocation or mapping primitives,
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/// such as [`CoherentAllocation::alloc_attrs`].
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unsafe fn dma_set_max_seg_size(&self, size: u32) {
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// SAFETY:
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// - By the type invariant of `device::Device`, `self.as_ref().as_raw()` is valid.
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// - The safety requirement of this function guarantees that there are no concurrent calls
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// to DMA allocation and mapping primitives using this parameter.
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unsafe { bindings::dma_set_max_seg_size(self.as_ref().as_raw(), size) }
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}
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}
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/// A DMA mask that holds a bitmask with the lowest `n` bits set.