diff options
Diffstat (limited to 'rust/kernel')
| -rw-r--r-- | rust/kernel/dma.rs | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs index acc65b1e0f24..909d56fd5118 100644 --- a/rust/kernel/dma.rs +++ b/rust/kernel/dma.rs @@ -85,6 +85,23 @@ pub trait Device: AsRef<device::Device<Core>> { bindings::dma_set_mask_and_coherent(self.as_ref().as_raw(), mask.value()) }) } + + /// Set the maximum size of a single DMA segment the device may request. + /// + /// This method is usually called once from `probe()` as soon as the device capabilities are + /// known. + /// + /// # Safety + /// + /// This method must not be called concurrently with any DMA allocation or mapping primitives, + /// such as [`CoherentAllocation::alloc_attrs`]. + unsafe fn dma_set_max_seg_size(&self, size: u32) { + // SAFETY: + // - By the type invariant of `device::Device`, `self.as_ref().as_raw()` is valid. + // - The safety requirement of this function guarantees that there are no concurrent calls + // to DMA allocation and mapping primitives using this parameter. + unsafe { bindings::dma_set_max_seg_size(self.as_ref().as_raw(), size) } + } } /// A DMA mask that holds a bitmask with the lowest `n` bits set. |