1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

//! Definition of phyical, virtual addresses and helper functions.

use crate::PAGE_SIZE;

/// Physical address.
pub type PhysAddr = usize;

/// Virtual address.
pub type VirtAddr = usize;

/// Device address.
pub type DevVAddr = usize;

pub const fn align_down(addr: usize) -> usize {
    addr & !(PAGE_SIZE - 1)
}

pub const fn align_up(addr: usize) -> usize {
    (addr + PAGE_SIZE - 1) & !(PAGE_SIZE - 1)
}

pub const fn is_aligned(addr: usize) -> bool {
    page_offset(addr) == 0
}

pub const fn page_count(size: usize) -> usize {
    align_up(size) / PAGE_SIZE
}

pub const fn page_offset(addr: usize) -> usize {
    addr & (PAGE_SIZE - 1)
}