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Now construction of PA/VA only uses 56/39 bits.

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This commit is contained in:
Yifan Wu 2021-11-13 02:56:43 -08:00
parent a5f972b77e
commit 1d307c6582
2 changed files with 11 additions and 6 deletions
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13
os/src/mm/address.rs
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@ -2,6 +2,11 @@ use crate::config::{PAGE_SIZE, PAGE_SIZE_BITS};
use super::PageTableEntry;
use core::fmt::{self, Debug, Formatter};
const PA_WIDTH_SV39: usize = 56;
const VA_WIDTH_SV39: usize = 39;
const PPN_WIDTH_SV39: usize = PA_WIDTH_SV39 - PAGE_SIZE_BITS;
const VPN_WIDTH_SV39: usize = VA_WIDTH_SV39 - PAGE_SIZE_BITS;
/// Definitions
#[derive(Copy, Clone, Ord, PartialOrd, Eq, PartialEq)]
pub struct PhysAddr(pub usize);
@ -43,16 +48,16 @@ impl Debug for PhysPageNum {
/// usize -> T: usize.into()
impl From<usize> for PhysAddr {
fn from(v: usize) -> Self { Self(v) }
fn from(v: usize) -> Self { Self(v & ( (1 << PA_WIDTH_SV39) - 1 )) }
}
impl From<usize> for PhysPageNum {
fn from(v: usize) -> Self { Self(v) }
fn from(v: usize) -> Self { Self(v & ( (1 << PPN_WIDTH_SV39) - 1 )) }
}
impl From<usize> for VirtAddr {
fn from(v: usize) -> Self { Self(v) }
fn from(v: usize) -> Self { Self(v & ( (1 << VA_WIDTH_SV39) - 1 )) }
}
impl From<usize> for VirtPageNum {
fn from(v: usize) -> Self { Self(v) }
fn from(v: usize) -> Self { Self(v & ( (1 << VPN_WIDTH_SV39) - 1 )) }
}
impl From<PhysAddr> for usize {
fn from(v: PhysAddr) -> Self { v.0 }