rust: alloc: add doctest for `ArrayLayout::new()`

Add a rustdoc example and Kunit test to the `ArrayLayout` struct's
`ArrayLayout::new()` function.

This patch depends on the first patch in this ser

rust: alloc: add doctest for `ArrayLayout::new()`

Add a rustdoc example and Kunit test to the `ArrayLayout` struct's
`ArrayLayout::new()` function.

This patch depends on the first patch in this series in order for the
KUnit test to compile.

Suggested-by: Boqun Feng <[email protected]>
Link: https://github.com/Rust-for-Linux/linux/issues/1131
Reviewed-by: Danilo Krummrich <[email protected]>
Signed-off-by: Jimmy Ostler <[email protected]>
Link: https://lore.kernel.org/r/f1564da5bcaa6be87aee312767a1d1694a03d1b7.1734674670.git.jtostler1@gmail.com
[ Added periods to example comments. Reworded title. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: Fix `ArrayLayout` allocations

We were accidentally allocating a layout for the *square* of the object
size due to a variable shadowing mishap.

Fixes memory bloat and page allocation fa

rust: alloc: Fix `ArrayLayout` allocations

We were accidentally allocating a layout for the *square* of the object
size due to a variable shadowing mishap.

Fixes memory bloat and page allocation failures in drm/asahi.

Reported-by: Janne Grunau <[email protected]>
Fixes: 9e7bbfa18276 ("rust: alloc: introduce `ArrayLayout`")
Signed-off-by: Asahi Lina <[email protected]>
Acked-by: Danilo Krummrich <[email protected]>
Reviewed-by: Neal Gompa <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...

rust: alloc: introduce `ArrayLayout`

When allocating memory for arrays using allocators, the `Layout::array`
function is typically used. It returns a result, since the given size
might be too big. H

rust: alloc: introduce `ArrayLayout`

When allocating memory for arrays using allocators, the `Layout::array`
function is typically used. It returns a result, since the given size
might be too big. However, `Vec` and its iterators store their allocated
capacity and thus they already did check that the size is not too big.

The `ArrayLayout` type provides this exact behavior, as it can be
infallibly converted into a `Layout`. Instead of a `usize` capacity,
`Vec` and other similar array-storing types can use `ArrayLayout`
instead.

Reviewed-by: Gary Guo <[email protected]>
Signed-off-by: Benno Lossin <[email protected]>
Signed-off-by: Danilo Krummrich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Formatted a few comments. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

show more ...