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rust: dma: make use of start_ptr() and start_ptr_mut()

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Using start_ptr() and start_ptr_mut() has the advantage that we inherit
the requirements the a mutable or immutable reference from those
methods.

Hence, use them instead of self.cpu_addr.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251103190655.2326191-1-dakr@kernel.org
[ Keep using self.cpu_addr in item_from_index(). - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
This commit is contained in:
Danilo Krummrich
2025-11-03 20:06:49 +01:00
parent d8407396f1
commit f7afdc4737
1 changed files with 8 additions and 4 deletions
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12
rust/kernel/dma.rs
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@@ -505,7 +505,7 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
// data is also guaranteed by the safety requirements of the function.
// - `offset + count` can't overflow since it is smaller than `self.count` and we've checked
// that `self.count` won't overflow early in the constructor.
Ok(unsafe { core::slice::from_raw_parts(self.cpu_addr.add(offset), count) })
Ok(unsafe { core::slice::from_raw_parts(self.start_ptr().add(offset), count) })
}
/// Performs the same functionality as [`CoherentAllocation::as_slice`], except that a mutable
@@ -525,7 +525,7 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
// data is also guaranteed by the safety requirements of the function.
// - `offset + count` can't overflow since it is smaller than `self.count` and we've checked
// that `self.count` won't overflow early in the constructor.
Ok(unsafe { core::slice::from_raw_parts_mut(self.cpu_addr.add(offset), count) })
Ok(unsafe { core::slice::from_raw_parts_mut(self.start_ptr_mut().add(offset), count) })
}
/// Writes data to the region starting from `offset`. `offset` is in units of `T`, not the
@@ -557,7 +557,11 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
// - `offset + count` can't overflow since it is smaller than `self.count` and we've checked
// that `self.count` won't overflow early in the constructor.
unsafe {
core::ptr::copy_nonoverlapping(src.as_ptr(), self.cpu_addr.add(offset), src.len())
core::ptr::copy_nonoverlapping(
src.as_ptr(),
self.start_ptr_mut().add(offset),
src.len(),
)
};
Ok(())
}
@@ -637,7 +641,7 @@ impl<T: AsBytes + FromBytes> Drop for CoherentAllocation<T> {
bindings::dma_free_attrs(
self.dev.as_raw(),
size,
self.cpu_addr.cast(),
self.start_ptr_mut().cast(),
self.dma_handle,
self.dma_attrs.as_raw(),
)