Move ops up from paging module for generalization.

src/addr.rs

@@ -1,12 +1,10 @@
 //! Physical and virtual addresses manipulation
 
+use crate::ops::{CheckedAdd, CheckedSub};
 use core::fmt;
 use core::ops::{Add, AddAssign, Sub, SubAssign};
 
-use crate::structures::paging::{
-    ops::{CheckedAdd, CheckedSub},
-    PageOffset, PageTableIndex,
-};
+use crate::structures::paging::{PageOffset, PageTableIndex};
 use bit_field::BitField;
 
 /// A canonical 64-bit virtual memory address.
@@ -586,7 +584,7 @@ impl Sub<PhysAddr> for PhysAddr {
 /// the address is canonical or not.
 #[inline]
 const fn is_canonical(addr: u64) -> Option<u64> {
-    let msb = (addr & 0xffff800000000000) >> 47;
+    let msb = (addr >> 47) & 0x1ffff;
 
     // The most-significant 17 bits must all be one or all be 0.
     if msb == 0x0 || msb == 0x1ffff {

src/lib.rs

@@ -63,6 +63,7 @@ pub(crate) mod asm;
 
 pub mod addr;
 pub mod instructions;
+pub mod ops;
 pub mod registers;
 pub mod structures;
 

src/structures/paging/mod.rs

@@ -19,6 +19,5 @@ pub use self::page_table::{PageOffset, PageTable, PageTableFlags, PageTableIndex
 pub mod frame;
 mod frame_alloc;
 pub mod mapper;
-pub mod ops;
 pub mod page;
 pub mod page_table;