garentyler/xv6-riscv
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Move push_off()/pop_off() into trap.rs and rename to push_intr_off() and pop_intr_off()

Browse Source
This commit is contained in:
Garen Tyler 2023-10-28 16:17:14 -06:00
parent c593250549
commit a1f88ff034
Signed by: garentyler
GPG Key ID: D7A048C454CB7054
3 changed files with 46 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
kernel/rustkernel/src/sync/spinlock.rs
View File

@ -1,6 +1,6 @@
use crate::{
proc::{mycpu, Cpu},
riscv,
trap::{push_intr_off, pop_intr_off},
};
use core::{
ffi::c_char,
@ -37,7 +37,7 @@ impl Spinlock {
self.cpu == unsafe { mycpu() } && self.locked.load(Ordering::Relaxed)
}
pub unsafe fn lock_unguarded(&self) {
push_off();
push_intr_off();
if self.held_by_current_cpu() {
panic!("Attempt to acquire twice by the same CPU");
@ -68,7 +68,7 @@ impl Spinlock {
this.cpu = null_mut();
this.locked.store(false, Ordering::Release);
pop_off();
pop_intr_off();
}
}
@ -100,37 +100,3 @@ pub unsafe extern "C" fn acquire(lock: *mut Spinlock) {
pub unsafe extern "C" fn release(lock: *mut Spinlock) {
(*lock).unlock();
}
// push_off/pop_off are like intr_off()/intr_on() except that they are matched:
// it takes two pop_off()s to undo two push_off()s. Also, if interrupts
// are initially off, then push_off, pop_off leaves them off.
#[no_mangle]
pub unsafe extern "C" fn push_off() {
let old = riscv::intr_get();
let cpu = mycpu();
riscv::intr_off();
if (*cpu).interrupt_disable_layers == 0 {
(*cpu).previous_interrupts_enabled = old;
}
(*cpu).interrupt_disable_layers += 1;
}
#[no_mangle]
pub unsafe extern "C" fn pop_off() {
let cpu = mycpu();
if riscv::intr_get() == 1 {
// crate::panic_byte(b'0');
panic!("pop_off - interruptible");
} else if (*cpu).interrupt_disable_layers < 1 {
// crate::panic_byte(b'1');
panic!("pop_off");
}
(*cpu).interrupt_disable_layers -= 1;
if (*cpu).interrupt_disable_layers == 0 && (*cpu).previous_interrupts_enabled == 1 {
riscv::intr_on();
}
}

9
kernel/rustkernel/src/sync/spinmutex.rs
View File

@ -17,13 +17,22 @@ impl<T> SpinMutex<T> {
}
}
pub fn lock(&self) -> SpinMutexGuard<'_, T> {
unsafe {
crate::trap::push_intr_off();
}
while self.locked.swap(true, Ordering::Acquire) {
core::hint::spin_loop();
}
SpinMutexGuard { mutex: self }
}
pub unsafe fn unlock(&self) {
self.locked.store(false, Ordering::Release);
unsafe {
crate::trap::pop_intr_off();
}
}
}
unsafe impl<T> Sync for SpinMutex<T> where T: Send {}

34
kernel/rustkernel/src/trap.rs
View File

@ -278,3 +278,37 @@ pub unsafe extern "C" fn usertrap() {
usertrapret();
}
// push_intr_off/pop_intr_off are like intr_off()/intr_on() except that they are matched:
// it takes two pop_intr_off()s to undo two push_intr_off()s. Also, if interrupts
// are initially off, then push_intr_off, pop_intr_off leaves them off.
#[no_mangle]
pub unsafe extern "C" fn push_intr_off() {
let old = crate::riscv::intr_get();
let cpu = mycpu();
crate::riscv::intr_off();
if (*cpu).interrupt_disable_layers == 0 {
(*cpu).previous_interrupts_enabled = old;
}
(*cpu).interrupt_disable_layers += 1;
}
#[no_mangle]
pub unsafe extern "C" fn pop_intr_off() {
let cpu = mycpu();
if crate::riscv::intr_get() == 1 {
// crate::panic_byte(b'0');
panic!("pop_intr_off - interruptible");
} else if (*cpu).interrupt_disable_layers < 1 {
// crate::panic_byte(b'1');
panic!("pop_intr_off");
}
(*cpu).interrupt_disable_layers -= 1;
if (*cpu).interrupt_disable_layers == 0 && (*cpu).previous_interrupts_enabled == 1 {
crate::riscv::intr_on();
}
}