From: Eliot Courtney <ecourtney@nvidia.com>
To: "Danilo Krummrich" <dakr@kernel.org>,
"Alexandre Courbot" <acourbot@nvidia.com>,
"Alice Ryhl" <aliceryhl@google.com>,
"David Airlie" <airlied@gmail.com>,
"Simona Vetter" <simona@ffwll.ch>,
"Abdiel Janulgue" <abdiel.janulgue@gmail.com>,
"Daniel Almeida" <daniel.almeida@collabora.com>,
"Robin Murphy" <robin.murphy@arm.com>,
"Andreas Hindborg" <a.hindborg@kernel.org>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <lossin@kernel.org>,
"Trevor Gross" <tmgross@umich.edu>
Cc: nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org, driver-core@lists.linux.dev,
rust-for-linux@vger.kernel.org,
Eliot Courtney <ecourtney@nvidia.com>
Subject: [PATCH 5/9] rust: dma: rename try_item_from_index to try_ptr_at
Date: Fri, 30 Jan 2026 17:34:08 +0900 [thread overview]
Message-ID: <20260130-coherent-array-v1-5-bcd672dacc70@nvidia.com> (raw)
In-Reply-To: <20260130-coherent-array-v1-0-bcd672dacc70@nvidia.com>
This function returns a pointer, so rename it to be clearer about what
it is getting.
Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
rust/kernel/dma.rs | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs
index 03fc001eb983..e4bca7a18ac1 100644
--- a/rust/kernel/dma.rs
+++ b/rust/kernel/dma.rs
@@ -559,7 +559,7 @@ pub unsafe fn try_write(&mut self, src: &[T], offset: usize) -> Result {
/// Public but hidden since it should only be used from [`try_dma_read`] and [`try_dma_write`]
/// macros.
#[doc(hidden)]
- pub fn try_item_from_index(&self, offset: usize) -> Result<*mut T> {
+ pub fn try_ptr_at(&self, offset: usize) -> Result<*mut T> {
if offset >= self.count {
return Err(EINVAL);
}
@@ -863,12 +863,12 @@ unsafe impl<T: AsBytes + FromBytes + Send, Size: AllocationSize> Send
macro_rules! try_dma_read {
($dma:expr, $idx:expr, $($field:tt)*) => {{
(|| -> ::core::result::Result<_, $crate::error::Error> {
- let item = $crate::dma::CoherentAllocation::try_item_from_index(&$dma, $idx)?;
- // SAFETY: `try_item_from_index` ensures that `item` is always a valid pointer
- // and can be dereferenced. The compiler also further validates the expression
- // on whether `field` is a member of `item` when expanded by the macro.
+ let ptr = $crate::dma::CoherentAllocation::try_ptr_at(&$dma, $idx)?;
+ // SAFETY: `try_ptr_at` ensures that `ptr` is always a valid pointer and can be
+ // dereferenced. The compiler also further validates the expression on whether `field`
+ // is a member of `ptr` when expanded by the macro.
unsafe {
- let ptr_field = ::core::ptr::addr_of!((*item) $($field)*);
+ let ptr_field = ::core::ptr::addr_of!((*ptr) $($field)*);
::core::result::Result::Ok(
$crate::dma::CoherentAllocation::field_read(&$dma, ptr_field)
)
@@ -904,20 +904,20 @@ macro_rules! try_dma_read {
macro_rules! try_dma_write {
($dma:expr, $idx:expr, = $val:expr) => {
(|| -> ::core::result::Result<_, $crate::error::Error> {
- let item = $crate::dma::CoherentAllocation::try_item_from_index(&$dma, $idx)?;
- // SAFETY: `try_item_from_index` ensures that `item` is always a valid item.
- unsafe { $crate::dma::CoherentAllocation::field_write(&$dma, item, $val) }
+ let ptr = $crate::dma::CoherentAllocation::try_ptr_at(&$dma, $idx)?;
+ // SAFETY: `try_ptr_at` ensures that `ptr` is always a valid ptr.
+ unsafe { $crate::dma::CoherentAllocation::field_write(&$dma, ptr, $val) }
::core::result::Result::Ok(())
})()
};
($dma:expr, $idx:expr, $(.$field:ident)* = $val:expr) => {
(|| -> ::core::result::Result<_, $crate::error::Error> {
- let item = $crate::dma::CoherentAllocation::try_item_from_index(&$dma, $idx)?;
- // SAFETY: `try_item_from_index` ensures that `item` is always a valid pointer
- // and can be dereferenced. The compiler also further validates the expression
- // on whether `field` is a member of `item` when expanded by the macro.
+ let ptr = $crate::dma::CoherentAllocation::try_ptr_at(&$dma, $idx)?;
+ // SAFETY: `try_ptr_at` ensures that `ptr` is always a valid pointer and can be
+ // dereferenced. The compiler also further validates the expression on whether `field`
+ // is a member of `ptr` when expanded by the macro.
unsafe {
- let ptr_field = ::core::ptr::addr_of_mut!((*item) $(.$field)*);
+ let ptr_field = ::core::ptr::addr_of_mut!((*ptr) $(.$field)*);
$crate::dma::CoherentAllocation::field_write(&$dma, ptr_field, $val)
}
::core::result::Result::Ok(())
--
2.52.0
next prev parent reply other threads:[~2026-01-30 8:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-30 8:34 [PATCH 0/9] rust: dma: add CoherentArray for compile-time sized allocations Eliot Courtney
2026-01-30 8:34 ` [PATCH 1/9] rust: dma: rename CoherentAllocation fallible methods Eliot Courtney
2026-01-30 8:34 ` [PATCH 2/9] rust: dma: parameterize CoherentAllocation with AllocationSize Eliot Courtney
2026-01-30 8:34 ` [PATCH 3/9] rust: dma: add CoherentArray for compile-time sized allocations Eliot Courtney
2026-01-30 8:34 ` [PATCH 4/9] rust: dma: simplify try_dma_read! and try_dma_write! Eliot Courtney
2026-01-30 8:34 ` Eliot Courtney [this message]
2026-01-30 8:34 ` [PATCH 6/9] rust: dma: add dma_read! and dma_write! macros Eliot Courtney
2026-01-30 10:26 ` Alice Ryhl
2026-01-30 8:34 ` [PATCH 7/9] rust: dma: implement decay from CoherentArray to CoherentSlice Eliot Courtney
2026-01-30 8:34 ` [PATCH 8/9] rust: dma: add CoherentObject for single element allocations Eliot Courtney
2026-01-30 8:34 ` [PATCH 9/9] gpu: nova-core: migrate to CoherentArray and CoherentObject Eliot Courtney
2026-01-31 12:27 ` [PATCH 0/9] rust: dma: add CoherentArray for compile-time sized allocations Danilo Krummrich
2026-01-31 13:16 ` Alexandre Courbot
2026-01-31 13:56 ` Danilo Krummrich
2026-02-02 14:22 ` Gary Guo
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