rust: alloc: cleanup imports and use "kernel vertical" style

Change all imports in the alloc module to use the "kernel vertical"
import style [1].

While at it, drop unnecessary imports covered by prelude::*.

Link: https://docs.kernel.org/rust/coding-guidelines.html#imports [1]
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Link: https://patch.msgid.link/20260513190946.619810-1-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

rust/kernel/alloc.rs

@@ -22,8 +22,12 @@
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 pub struct AllocError;
 
-use crate::error::{code::EINVAL, Result};
-use core::{alloc::Layout, ptr::NonNull};
+use crate::prelude::*;
+
+use core::{
+    alloc::Layout,
+    ptr::NonNull, //
+};
 
 /// Flags to be used when allocating memory.
 ///

rust/kernel/alloc/allocator.rs

@@ -8,14 +8,25 @@
 //!
 //! Reference: <https://docs.kernel.org/core-api/memory-allocation.html>
 
-use super::Flags;
-use core::alloc::Layout;
-use core::ptr;
-use core::ptr::NonNull;
+use super::{
+    AllocError,
+    Allocator,
+    Flags,
+    NumaNode, //
+};
 
-use crate::alloc::{AllocError, Allocator, NumaNode};
-use crate::bindings;
-use crate::page;
+use crate::{
+    bindings,
+    page, //
+};
+
+use core::{
+    alloc::Layout,
+    ptr::{
+        self,
+        NonNull, //
+    }, //
+};
 
 const ARCH_KMALLOC_MINALIGN: usize = bindings::ARCH_KMALLOC_MINALIGN;
 

rust/kernel/alloc/allocator/iter.rs

@@ -1,9 +1,13 @@
 // SPDX-License-Identifier: GPL-2.0
 
 use super::Vmalloc;
+
 use crate::page;
-use core::marker::PhantomData;
-use core::ptr::NonNull;
+
+use core::{
+    marker::PhantomData,
+    ptr::NonNull, //
+};
 
 /// An [`Iterator`] of [`page::BorrowedPage`] items owned by a [`Vmalloc`] allocation.
 ///

rust/kernel/alloc/kbox.rs

@@ -3,24 +3,47 @@
 //! Implementation of [`Box`].
 
 #[allow(unused_imports)] // Used in doc comments.
-use super::allocator::{KVmalloc, Kmalloc, Vmalloc, VmallocPageIter};
-use super::{AllocError, Allocator, Flags, NumaNode};
-use core::alloc::Layout;
-use core::borrow::{Borrow, BorrowMut};
-use core::marker::PhantomData;
-use core::mem::ManuallyDrop;
-use core::mem::MaybeUninit;
-use core::ops::{Deref, DerefMut};
-use core::pin::Pin;
-use core::ptr::NonNull;
-use core::result::Result;
+use super::allocator::{
+    KVmalloc,
+    Kmalloc,
+    Vmalloc,
+    VmallocPageIter, //
+};
 
-use crate::ffi::c_void;
-use crate::fmt;
-use crate::init::InPlaceInit;
-use crate::page::AsPageIter;
-use crate::types::ForeignOwnable;
-use pin_init::{InPlaceWrite, Init, PinInit, ZeroableOption};
+use super::{
+    AllocError,
+    Allocator,
+    Flags,
+    NumaNode, //
+};
+
+use crate::{
+    fmt,
+    page::AsPageIter,
+    prelude::*,
+    types::ForeignOwnable, //
+};
+
+use core::{
+    alloc::Layout,
+    borrow::{
+        Borrow,
+        BorrowMut, //
+    },
+    marker::PhantomData,
+    mem::{
+        ManuallyDrop,
+        MaybeUninit, //
+    },
+    ops::{
+        Deref,
+        DerefMut, //
+    },
+    ptr::NonNull,
+    result::Result, //
+};
+
+use pin_init::ZeroableOption;
 
 /// The kernel's [`Box`] type -- a heap allocation for a single value of type `T`.
 ///

rust/kernel/alloc/kvec.rs

@@ -3,29 +3,52 @@
 //! Implementation of [`Vec`].
 
 use super::{
-    allocator::{KVmalloc, Kmalloc, Vmalloc, VmallocPageIter},
+    allocator::{
+        KVmalloc,
+        Kmalloc,
+        Vmalloc,
+        VmallocPageIter, //
+    },
     layout::ArrayLayout,
-    AllocError, Allocator, Box, Flags, NumaNode,
+    AllocError,
+    Allocator,
+    Box,
+    Flags,
+    NumaNode, //
 };
+
 use crate::{
     fmt,
     page::{
         AsPageIter,
         PAGE_SIZE, //
-    },
+    }, //
 };
+
 use core::{
-    borrow::{Borrow, BorrowMut},
+    borrow::{
+        Borrow,
+        BorrowMut, //
+    },
     marker::PhantomData,
-    mem::{ManuallyDrop, MaybeUninit},
-    ops::Deref,
-    ops::DerefMut,
-    ops::Index,
-    ops::IndexMut,
-    ptr,
-    ptr::NonNull,
-    slice,
-    slice::SliceIndex,
+    mem::{
+        ManuallyDrop,
+        MaybeUninit, //
+    },
+    ops::{
+        Deref,
+        DerefMut,
+        Index,
+        IndexMut, //
+    },
+    ptr::{
+        self,
+        NonNull, //
+    },
+    slice::{
+        self,
+        SliceIndex, //
+    }, //
 };
 
 mod errors;

rust/kernel/alloc/kvec/errors.rs

@@ -2,8 +2,10 @@
 
 //! Errors for the [`Vec`] type.
 
-use kernel::fmt;
-use kernel::prelude::*;
+use crate::{
+    fmt,
+    prelude::*, //
+};
 
 /// Error type for [`Vec::push_within_capacity`].
 pub struct PushError<T>(pub T);

rust/kernel/alloc/layout.rs

@@ -4,7 +4,10 @@
 //!
 //! Custom layout types extending or improving [`Layout`].
 
-use core::{alloc::Layout, marker::PhantomData};
+use core::{
+    alloc::Layout,
+    marker::PhantomData, //
+};
 
 /// Error when constructing an [`ArrayLayout`].
 pub struct LayoutError;