os/mm/address/
operations.rs

1//! Address Operations Module
2//!
3//! 此模块定义了用于自定义地址类型（如 Paddr 和 Vaddr）的数学、位操作和对齐 Trait。
4//! 目标是使强类型地址在使用时具备与 `usize` 相同的运算能力，同时保持类型安全。
5
6use crate::config::PAGE_SIZE;
7use core::ops::{
8    Add, AddAssign, BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Shl, ShlAssign,
9    Shr, ShrAssign, Sub, SubAssign,
10};
11
12/// [UsizeConvert] Trait
13/// ---------------------
14/// 允许类型与 usize 之间互相转换。
15/// 任何自定义的地址或页码类型 (例如 Paddr, Vaddr) 必须实现此 Trait，
16/// 以便进行底层数值操作。
17pub trait UsizeConvert: Copy + Clone + PartialEq + PartialOrd + Eq + Ord {
18    /// 将类型转换为 usize。
19    fn as_usize(&self) -> usize;
20    /// 将 usize 转换为类型。
21    fn from_usize(value: usize) -> Self;
22}
23
24/// [CalcOps] Trait
25/// ---------------------
26/// 定义了地址或页码类型所需的所有算术和位操作。
27/// 统一了类型自身以及类型与 usize 之间的加、减、位运算和移位操作。
28pub trait CalcOps:
29    UsizeConvert
30    + Add<usize>
31    + Add<Self>
32    + AddAssign<usize>
33    + AddAssign<Self>
34    + Sub<usize>
35    + Sub<Self>
36    + SubAssign<usize>
37    + SubAssign<Self>
38    + BitAnd<usize>
39    + BitAnd<Self>
40    + BitAndAssign<usize>
41    + BitAndAssign<Self>
42    + BitOr<usize>
43    + BitOr<Self>
44    + BitOrAssign<usize>
45    + BitOrAssign<Self>
46    + BitXor<usize>
47    + BitXor<Self>
48    + BitXorAssign<usize>
49    + BitXorAssign<Self>
50    + Shl<usize>
51    + ShlAssign<usize>
52    + Shr<usize>
53    + ShrAssign<usize>
54{
55}
56
57/// `impl_calc_ops!` 宏
58/// ---------------------
59/// 快速为给定类型实现所有 [CalcOps] 所需的 Trait 方法。
60/// 这些实现通过先转换为 usize 进行计算，然后将结果转回类型来完成。
61///
62/// # 使用示例
63/// ```ignore
64/// // 在 MyAddr 上实现 UsizeConvert
65/// impl_calc_ops!(MyAddr);
66/// ```
67#[macro_export]
68macro_rules! impl_calc_ops {
69    ($type:ty) => {
70        // --- 加法实现 ---
71        impl core::ops::Add<usize> for $type {
72            type Output = Self;
73            fn add(self, rhs: usize) -> Self::Output {
74                $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() + rhs)
75            }
76        }
77        impl core::ops::Add<Self> for $type {
78            type Output = Self;
79            fn add(self, rhs: Self) -> Self::Output {
80                $crate::mm::address::operations::UsizeConvert::from_usize(
81                    self.as_usize() + rhs.as_usize(),
82                )
83            }
84        }
85        impl core::ops::AddAssign<usize> for $type {
86            fn add_assign(&mut self, rhs: usize) {
87                *self =
88                    $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() + rhs)
89            }
90        }
91        impl core::ops::AddAssign<Self> for $type {
92            fn add_assign(&mut self, rhs: Self) {
93                *self = $crate::mm::address::operations::UsizeConvert::from_usize(
94                    self.as_usize() + rhs.as_usize(),
95                )
96            }
97        }
98        // --- 减法实现 ---
99        impl core::ops::Sub<usize> for $type {
100            type Output = Self;
101            fn sub(self, rhs: usize) -> Self::Output {
102                $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() - rhs)
103            }
104        }
105        impl core::ops::Sub<Self> for $type {
106            type Output = Self;
107            fn sub(self, rhs: Self) -> Self::Output {
108                $crate::mm::address::operations::UsizeConvert::from_usize(
109                    self.as_usize() - rhs.as_usize(),
110                )
111            }
112        }
113        impl core::ops::SubAssign<usize> for $type {
114            fn sub_assign(&mut self, rhs: usize) {
115                *self =
116                    $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() - rhs)
117            }
118        }
119        impl core::ops::SubAssign<Self> for $type {
120            fn sub_assign(&mut self, rhs: Self) {
121                *self = $crate::mm::address::operations::UsizeConvert::from_usize(
122                    self.as_usize() - rhs.as_usize(),
123                )
124            }
125        }
126        // --- 位与实现 ---
127        impl core::ops::BitAnd<usize> for $type {
128            type Output = Self;
129            fn bitand(self, rhs: usize) -> Self::Output {
130                $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() & rhs)
131            }
132        }
133        impl core::ops::BitAnd<Self> for $type {
134            type Output = Self;
135            fn bitand(self, rhs: Self) -> Self::Output {
136                $crate::mm::address::operations::UsizeConvert::from_usize(
137                    self.as_usize() & rhs.as_usize(),
138                )
139            }
140        }
141        impl core::ops::BitAndAssign<usize> for $type {
142            fn bitand_assign(&mut self, rhs: usize) {
143                *self =
144                    $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() & rhs)
145            }
146        }
147        impl core::ops::BitAndAssign<Self> for $type {
148            fn bitand_assign(&mut self, rhs: Self) {
149                *self = $crate::mm::address::operations::UsizeConvert::from_usize(
150                    self.as_usize() & rhs.as_usize(),
151                )
152            }
153        }
154        // --- 位或实现 ---
155        impl core::ops::BitOr<usize> for $type {
156            type Output = Self;
157            fn bitor(self, rhs: usize) -> Self::Output {
158                $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() | rhs)
159            }
160        }
161        impl core::ops::BitOr<Self> for $type {
162            type Output = Self;
163            fn bitor(self, rhs: Self) -> Self::Output {
164                $crate::mm::address::operations::UsizeConvert::from_usize(
165                    self.as_usize() | rhs.as_usize(),
166                )
167            }
168        }
169        impl core::ops::BitOrAssign<usize> for $type {
170            fn bitor_assign(&mut self, rhs: usize) {
171                *self =
172                    $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() | rhs)
173            }
174        }
175        impl core::ops::BitOrAssign<Self> for $type {
176            fn bitor_assign(&mut self, rhs: Self) {
177                *self = $crate::mm::address::operations::UsizeConvert::from_usize(
178                    self.as_usize() | rhs.as_usize(),
179                )
180            }
181        }
182        // --- 位异或实现 ---
183        impl core::ops::BitXor<usize> for $type {
184            type Output = Self;
185            fn bitxor(self, rhs: usize) -> Self::Output {
186                $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() ^ rhs)
187            }
188        }
189        impl core::ops::BitXor<Self> for $type {
190            type Output = Self;
191            fn bitxor(self, rhs: Self) -> Self::Output {
192                $crate::mm::address::operations::UsizeConvert::from_usize(
193                    self.as_usize() ^ rhs.as_usize(),
194                )
195            }
196        }
197        impl core::ops::BitXorAssign<usize> for $type {
198            fn bitxor_assign(&mut self, rhs: usize) {
199                *self =
200                    $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() ^ rhs)
201            }
202        }
203        impl core::ops::BitXorAssign<Self> for $type {
204            fn bitxor_assign(&mut self, rhs: Self) {
205                *self = $crate::mm::address::operations::UsizeConvert::from_usize(
206                    self.as_usize() ^ rhs.as_usize(),
207                )
208            }
209        }
210        // --- 移位实现 ---
211        impl core::ops::Shl<usize> for $type {
212            type Output = Self;
213            fn shl(self, rhs: usize) -> Self::Output {
214                $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() << rhs)
215            }
216        }
217        impl core::ops::ShlAssign<usize> for $type {
218            fn shl_assign(&mut self, rhs: usize) {
219                *self = $crate::mm::address::operations::UsizeConvert::from_usize(
220                    self.as_usize() << rhs,
221                )
222            }
223        }
224        impl core::ops::Shr<usize> for $type {
225            type Output = Self;
226            fn shr(self, rhs: usize) -> Self::Output {
227                $crate::mm::address::operations::UsizeConvert::from_usize(self.as_usize() >> rhs)
228            }
229        }
230        impl core::ops::ShrAssign<usize> for $type {
231            fn shr_assign(&mut self, rhs: usize) {
232                *self = $crate::mm::address::operations::UsizeConvert::from_usize(
233                    self.as_usize() >> rhs,
234                )
235            }
236        }
237        // 标记该类型已实现 CalcOps
238        impl $crate::mm::address::operations::CalcOps for $type {}
239    };
240}
241
242/// [AlignOps] Trait
243/// ---------------------
244/// 定义了地址对齐操作，例如检查对齐、向上对齐和向下对齐。
245///
246/// 注意: 所有对齐操作都要求 `alignment` 是 2 的幂。
247#[allow(dead_code)]
248pub trait AlignOps: UsizeConvert {
249    /// 检查地址是否已对齐到给定的对齐边界。
250    ///
251    /// # 参数
252    /// * `alignment`: 对齐边界（必须是 2 的幂）。
253    fn is_aligned(self, alignment: usize) -> bool {
254        debug_assert!(
255            alignment.is_power_of_two(),
256            "alignment must be a power of two"
257        );
258        let mask = alignment - 1;
259        // 检查地址的低位是否全为 0
260        self.as_usize() & mask == 0
261    }
262    /// 检查地址是否已页对齐（对齐到 `PAGE_SIZE`）。
263    fn is_page_aligned(self) -> bool {
264        self.is_aligned(PAGE_SIZE)
265    }
266    /// 将地址向上对齐到给定的对齐边界。
267    ///
268    /// # 参数
269    /// * `alignment`: 对齐边界（必须是 2 的幂）。
270    fn align_up(self, alignment: usize) -> Self {
271        debug_assert!(
272            alignment.is_power_of_two(),
273            "alignment must be a power of two"
274        );
275        let mask = alignment - 1;
276        // 核心逻辑: (addr + mask) & !mask
277        Self::from_usize((self.as_usize() + mask) & !mask)
278    }
279    /// 将地址向下对齐到给定的对齐边界。
280    ///
281    /// # 参数
282    /// * `alignment`: 对齐边界（必须是 2 的幂）。
283    fn align_down(self, alignment: usize) -> Self {
284        debug_assert!(
285            alignment.is_power_of_two(),
286            "alignment must be a power of two"
287        );
288        let mask = alignment - 1;
289        // 核心逻辑: addr & !mask
290        Self::from_usize(self.as_usize() & !mask)
291    }
292    /// 将地址向上对齐到页大小（`PAGE_SIZE`）。
293    fn align_up_to_page(self) -> Self {
294        self.align_up(PAGE_SIZE)
295    }
296    /// 将地址向下对齐到页大小（`PAGE_SIZE`）。
297    fn align_down_to_page(self) -> Self {
298        self.align_down(PAGE_SIZE)
299    }
300}
os/mm/address/operations.rs

os/mm/address/
operations.rs
