1 files changed, 149 insertions, 0 deletions
diff --git a/rust/kernel/mm.rs b/rust/kernel/mm.rs
new file mode 100644
index 000000000000..322f94f501e0
--- /dev/null
+++ b/rust/kernel/mm.rs
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Memory management.
+//!
+//! C header: [`include/linux/mm.h`](../../../../include/linux/mm.h)
+
+use crate::{bindings, pages, to_result, Result};
+
+/// Virtual memory.
+pub mod virt {
+    use super::*;
+
+    /// A wrapper for the kernel's `struct vm_area_struct`.
+    ///
+    /// It represents an area of virtual memory.
+    ///
+    /// # Invariants
+    ///
+    /// `vma` is always non-null and valid.
+    pub struct Area {
+        vma: *mut bindings::vm_area_struct,
+    }
+
+    impl Area {
+        /// Creates a new instance of a virtual memory area.
+        ///
+        /// # Safety
+        ///
+        /// Callers must ensure that `vma` is non-null and valid for the duration of the new area's
+        /// lifetime.
+        pub(crate) unsafe fn from_ptr(vma: *mut bindings::vm_area_struct) -> Self {
+            // INVARIANTS: The safety requirements guarantee the invariants.
+            Self { vma }
+        }
+
+        /// Returns the flags associated with the virtual memory area.
+        ///
+        /// The possible flags are a combination of the constants in [`flags`].
+        pub fn flags(&self) -> usize {
+            // SAFETY: `self.vma` is valid by the type invariants.
+            unsafe { (*self.vma).vm_flags as _ }
+        }
+
+        /// Sets the flags associated with the virtual memory area.
+        ///
+        /// The possible flags are a combination of the constants in [`flags`].
+        pub fn set_flags(&mut self, flags: usize) {
+            // SAFETY: `self.vma` is valid by the type invariants.
+            unsafe { (*self.vma).vm_flags = flags as _ };
+        }
+
+        /// Returns the start address of the virtual memory area.
+        pub fn start(&self) -> usize {
+            // SAFETY: `self.vma` is valid by the type invariants.
+            unsafe { (*self.vma).vm_start as _ }
+        }
+
+        /// Returns the end address of the virtual memory area.
+        pub fn end(&self) -> usize {
+            // SAFETY: `self.vma` is valid by the type invariants.
+            unsafe { (*self.vma).vm_end as _ }
+        }
+
+        /// Maps a single page at the given address within the virtual memory area.
+        pub fn insert_page(&mut self, address: usize, page: &pages::Pages<0>) -> Result {
+            // SAFETY: The page is guaranteed to be order 0 by the type system. The range of
+            // `address` is already checked by `vm_insert_page`. `self.vma` and `page.pages` are
+            // guaranteed by their repective type invariants to be valid.
+            to_result(|| unsafe { bindings::vm_insert_page(self.vma, address as _, page.pages) })
+        }
+    }
+
+    /// Container for [`Area`] flags.
+    pub mod flags {
+        use crate::bindings;
+
+        /// No flags are set.
+        pub const NONE: usize = bindings::VM_NONE as _;
+
+        /// Mapping allows reads.
+        pub const READ: usize = bindings::VM_READ as _;
+
+        /// Mapping allows writes.
+        pub const WRITE: usize = bindings::VM_WRITE as _;
+
+        /// Mapping allows execution.
+        pub const EXEC: usize = bindings::VM_EXEC as _;
+
+        /// Mapping is shared.
+        pub const SHARED: usize = bindings::VM_SHARED as _;
+
+        /// Mapping may be updated to allow reads.
+        pub const MAYREAD: usize = bindings::VM_MAYREAD as _;
+
+        /// Mapping may be updated to allow writes.
+        pub const MAYWRITE: usize = bindings::VM_MAYWRITE as _;
+
+        /// Mapping may be updated to allow execution.
+        pub const MAYEXEC: usize = bindings::VM_MAYEXEC as _;
+
+        /// Mapping may be updated to be shared.
+        pub const MAYSHARE: usize = bindings::VM_MAYSHARE as _;
+
+        /// Do not copy this vma on fork.
+        pub const DONTCOPY: usize = bindings::VM_DONTCOPY as _;
+
+        /// Cannot expand with mremap().
+        pub const DONTEXPAND: usize = bindings::VM_DONTEXPAND as _;
+
+        /// Lock the pages covered when they are faulted in.
+        pub const LOCKONFAULT: usize = bindings::VM_LOCKONFAULT as _;
+
+        /// Is a VM accounted object.
+        pub const ACCOUNT: usize = bindings::VM_ACCOUNT as _;
+
+        /// should the VM suppress accounting.
+        pub const NORESERVE: usize = bindings::VM_NORESERVE as _;
+
+        /// Huge TLB Page VM.
+        pub const HUGETLB: usize = bindings::VM_HUGETLB as _;
+
+        /// Synchronous page faults.
+        pub const SYNC: usize = bindings::VM_SYNC as _;
+
+        /// Architecture-specific flag.
+        pub const ARCH_1: usize = bindings::VM_ARCH_1 as _;
+
+        /// Wipe VMA contents in child..
+        pub const WIPEONFORK: usize = bindings::VM_WIPEONFORK as _;
+
+        /// Do not include in the core dump.
+        pub const DONTDUMP: usize = bindings::VM_DONTDUMP as _;
+
+        /// Not soft dirty clean area.
+        pub const SOFTDIRTY: usize = bindings::VM_SOFTDIRTY as _;
+
+        /// Can contain "struct page" and pure PFN pages.
+        pub const MIXEDMAP: usize = bindings::VM_MIXEDMAP as _;
+
+        /// MADV_HUGEPAGE marked this vma.
+        pub const HUGEPAGE: usize = bindings::VM_HUGEPAGE as _;
+
+        /// MADV_NOHUGEPAGE marked this vma.
+        pub const NOHUGEPAGE: usize = bindings::VM_NOHUGEPAGE as _;
+
+        /// KSM may merge identical pages.
+        pub const MERGEABLE: usize = bindings::VM_MERGEABLE as _;
+    }
+}