diff mbox series

[v3,03/13] rust: types: add `Opaque::raw_get`

Message ID 20230329223239.138757-4-y86-dev@protonmail.com
State New
Headers
Series Rust pin-init API for pinned initialization of structs |

Commit Message

y86-dev March 29, 2023, 10:33 p.m. UTC 
  From: Benno Lossin <y86-dev@protonmail.com>

This function mirrors `UnsafeCell::raw_get`. It avoids creating a
reference and allows solely using raw pointers.
The `pin-init` API will be using this, since uninitialized memory
requires raw pointers.

Signed-off-by: Benno Lossin <y86-dev@protonmail.com>
---
 rust/kernel/types.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

--
2.39.2

Comments

Gary Guo March 30, 2023, 10:49 a.m. UTC | #1 
On Wed, 29 Mar 2023 22:33:03 +0000
y86-dev@protonmail.com wrote:

> From: Benno Lossin <y86-dev@protonmail.com>
> 
> This function mirrors `UnsafeCell::raw_get`. It avoids creating a
> reference and allows solely using raw pointers.
> The `pin-init` API will be using this, since uninitialized memory
> requires raw pointers.
> 
> Signed-off-by: Benno Lossin <y86-dev@protonmail.com>

Reviewed-by: Gary Guo <gary@garyguo.net>

> ---
>  rust/kernel/types.rs | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
> index 9d0fdbc55843..ff2b2fac951d 100644
> --- a/rust/kernel/types.rs
> +++ b/rust/kernel/types.rs
> @@ -238,6 +238,14 @@ impl<T> Opaque<T> {
>      pub fn get(&self) -> *mut T {
>          UnsafeCell::raw_get(self.0.as_ptr())
>      }
> +
> +    /// Gets the value behind `this`.
> +    ///
> +    /// This function is useful to get access to the value without creating intermediate
> +    /// references.
> +    pub const fn raw_get(this: *const Self) -> *mut T {
> +        UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
> +    }
>  }
> 
>  /// A sum type that always holds either a value of type `L` or `R`.
> --
> 2.39.2
> 
>
Andreas Hindborg March 30, 2023, 12:32 p.m. UTC | #2 
y86-dev@protonmail.com writes:

> From: Benno Lossin <y86-dev@protonmail.com>
>
> This function mirrors `UnsafeCell::raw_get`. It avoids creating a
> reference and allows solely using raw pointers.
> The `pin-init` API will be using this, since uninitialized memory
> requires raw pointers.
>
> Signed-off-by: Benno Lossin <y86-dev@protonmail.com>
> ---

Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>

>  rust/kernel/types.rs | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
> index 9d0fdbc55843..ff2b2fac951d 100644
> --- a/rust/kernel/types.rs
> +++ b/rust/kernel/types.rs
> @@ -238,6 +238,14 @@ impl<T> Opaque<T> {
>      pub fn get(&self) -> *mut T {
>          UnsafeCell::raw_get(self.0.as_ptr())
>      }
> +
> +    /// Gets the value behind `this`.
> +    ///
> +    /// This function is useful to get access to the value without creating intermediate
> +    /// references.
> +    pub const fn raw_get(this: *const Self) -> *mut T {
> +        UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
> +    }
>  }
>
>  /// A sum type that always holds either a value of type `L` or `R`.
Alice Ryhl March 30, 2023, 1:33 p.m. UTC | #3 
On 3/30/23 00:33, y86-dev@protonmail.com wrote:
> From: Benno Lossin <y86-dev@protonmail.com>
> 
> This function mirrors `UnsafeCell::raw_get`. It avoids creating a
> reference and allows solely using raw pointers.
> The `pin-init` API will be using this, since uninitialized memory
> requires raw pointers.
> 
> Signed-off-by: Benno Lossin <y86-dev@protonmail.com>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
diff mbox series

Patch

diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 9d0fdbc55843..ff2b2fac951d 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -238,6 +238,14 @@  impl<T> Opaque<T> {
     pub fn get(&self) -> *mut T {
         UnsafeCell::raw_get(self.0.as_ptr())
     }
+
+    /// Gets the value behind `this`.
+    ///
+    /// This function is useful to get access to the value without creating intermediate
+    /// references.
+    pub const fn raw_get(this: *const Self) -> *mut T {
+        UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
+    }
 }

 /// A sum type that always holds either a value of type `L` or `R`.