[PATCH v3 3/3] rust: alloc: move `NumaNode` to the `numa` module

[Andreas Hindborg <a.hindborg@kernel.org>]

`NumaNode` identifies a NUMA node and is not specific to the allocator API.
Move it from the `alloc` module to the `numa` module so that NUMA related
items live together.

No functional change.

Suggested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/all/aiZvKPFCkqJUsP0a@google.com/
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
 rust/kernel/alloc.rs           | 30 ++++--------------------------
 rust/kernel/alloc/allocator.rs |  6 +++---
 rust/kernel/alloc/kbox.rs      |  4 ++--
 rust/kernel/alloc/kvec.rs      |  4 ++--
 rust/kernel/numa.rs            | 35 ++++++++++++++++++++++++++++++++++-
 5 files changed, 45 insertions(+), 34 deletions(-)

diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index 21067bde6860..9daddf540e7d 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -22,7 +22,10 @@
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub struct AllocError;
 
-use crate::prelude::*;
+use crate::{
+    numa::NumaNode,
+    prelude::*, //
+};
 
 use core::{
     alloc::Layout,
@@ -114,31 +117,6 @@ pub mod flags {
     pub const __GFP_NOWARN: Flags = Flags(bindings::__GFP_NOWARN);
 }
 
-/// Non Uniform Memory Access (NUMA) node identifier.
-#[derive(Clone, Copy, PartialEq)]
-pub struct NumaNode(i32);
-
-impl NumaNode {
-    /// Create a new NUMA node identifier (non-negative integer).
-    ///
-    /// Returns [`EINVAL`] if a negative id or an id exceeding [`bindings::MAX_NUMNODES`] is
-    /// specified.
-    pub fn new(node: i32) -> Result<Self> {
-        // MAX_NUMNODES never exceeds 2**10 because NODES_SHIFT is 0..10.
-        if node < 0 || node >= bindings::MAX_NUMNODES as i32 {
-            return Err(EINVAL);
-        }
-        Ok(Self(node))
-    }
-}
-
-/// Specify necessary constant to pass the information to Allocator that the caller doesn't care
-/// about the NUMA node to allocate memory from.
-impl NumaNode {
-    /// No node preference.
-    pub const NO_NODE: NumaNode = NumaNode(bindings::NUMA_NO_NODE);
-}
-
 /// The kernel's [`Allocator`] trait.
 ///
 /// An implementation of [`Allocator`] can allocate, re-allocate and free memory buffers described
diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs
index cd4203f27aed..4af50e20933b 100644
--- a/rust/kernel/alloc/allocator.rs
+++ b/rust/kernel/alloc/allocator.rs
@@ -11,12 +11,12 @@
 use super::{
     AllocError,
     Allocator,
-    Flags,
-    NumaNode, //
+    Flags, //
 };
 
 use crate::{
     bindings,
+    numa::NumaNode,
     page, //
 };
 
@@ -122,7 +122,7 @@ unsafe fn call(
         // - Those functions provide the guarantees of this function.
         let raw_ptr = unsafe {
             // If `size == 0` and `ptr != NULL` the memory behind the pointer is freed.
-            self.0(ptr.cast(), size, layout.align(), flags.0, nid.0).cast()
+            self.0(ptr.cast(), size, layout.align(), flags.0, nid.as_raw()).cast()
         };
 
         let ptr = if size == 0 {
diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs
index c63d6acdbb6f..0fa736c81287 100644
--- a/rust/kernel/alloc/kbox.rs
+++ b/rust/kernel/alloc/kbox.rs
@@ -13,12 +13,12 @@
 use super::{
     AllocError,
     Allocator,
-    Flags,
-    NumaNode, //
+    Flags, //
 };
 
 use crate::{
     fmt,
+    numa::NumaNode,
     page::AsPageIter,
     prelude::*,
     types::ForeignOwnable, //
diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs
index c7546b9da4fa..b669ca10b3f7 100644
--- a/rust/kernel/alloc/kvec.rs
+++ b/rust/kernel/alloc/kvec.rs
@@ -14,12 +14,12 @@
     AllocError,
     Allocator,
     Box,
-    Flags,
-    NumaNode, //
+    Flags, //
 };
 
 use crate::{
     fmt,
+    numa::NumaNode,
     page::{
         AsPageIter,
         PAGE_SIZE, //
diff --git a/rust/kernel/numa.rs b/rust/kernel/numa.rs
index 164e622d325f..4a3a880308f3 100644
--- a/rust/kernel/numa.rs
+++ b/rust/kernel/numa.rs
@@ -4,12 +4,15 @@
 //!
 //! C header: [`include/linux/nodemask.h`](srctree/include/linux/nodemask.h)
 
-use crate::bindings;
 #[cfg(CONFIG_NUMA)]
 use crate::sync::atomic::{
     Atomic,
     Relaxed, //
 };
+use crate::{
+    bindings,
+    prelude::*, //
+};
 
 /// Returns the number of online NUMA nodes.
 #[inline]
@@ -27,3 +30,33 @@ pub fn num_online_nodes() -> u32 {
         bindings::nr_online_nodes
     }
 }
+
+/// Non Uniform Memory Access (NUMA) node identifier.
+#[derive(Clone, Copy, PartialEq)]
+pub struct NumaNode(i32);
+
+impl NumaNode {
+    /// Create a new NUMA node identifier (non-negative integer).
+    ///
+    /// Returns [`EINVAL`] if a negative id or an id exceeding [`bindings::MAX_NUMNODES`] is
+    /// specified.
+    pub fn new(node: i32) -> Result<Self> {
+        // MAX_NUMNODES never exceeds 2**10 because NODES_SHIFT is 0..10.
+        if node < 0 || node >= bindings::MAX_NUMNODES as i32 {
+            return Err(EINVAL);
+        }
+        Ok(Self(node))
+    }
+
+    /// Get the raw representation of this node identifier.
+    pub(crate) fn as_raw(self) -> i32 {
+        self.0
+    }
+}
+
+/// Specify necessary constant to pass the information to Allocator that the caller doesn't care
+/// about the NUMA node to allocate memory from.
+impl NumaNode {
+    /// No node preference.
+    pub const NO_NODE: NumaNode = NumaNode(bindings::NUMA_NO_NODE);
+}

-- 
2.54.0