108 lines
3.4 KiB
Rust
108 lines
3.4 KiB
Rust
use core::{mem, str};
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use core::sync::atomic::{AtomicUsize, ATOMIC_USIZE_INIT, Ordering};
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use spin::{Mutex, Once};
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use arch::interrupt::irq::acknowledge;
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use context;
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use sync::WaitCondition;
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use syscall::error::*;
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use syscall::flag::EVENT_READ;
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use syscall::scheme::Scheme;
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pub static IRQ_SCHEME_ID: AtomicUsize = ATOMIC_USIZE_INIT;
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/// IRQ queues
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static ACKS: Mutex<[usize; 16]> = Mutex::new([0; 16]);
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static COUNTS: Mutex<[usize; 16]> = Mutex::new([0; 16]);
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static WAITS: Once<[WaitCondition; 16]> = Once::new();
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fn init_waits() -> [WaitCondition; 16] {
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[
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WaitCondition::new(), WaitCondition::new(), WaitCondition::new(), WaitCondition::new(),
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WaitCondition::new(), WaitCondition::new(), WaitCondition::new(), WaitCondition::new(),
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WaitCondition::new(), WaitCondition::new(), WaitCondition::new(), WaitCondition::new(),
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WaitCondition::new(), WaitCondition::new(), WaitCondition::new(), WaitCondition::new()
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]
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}
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/// Add to the input queue
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#[no_mangle]
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pub extern fn irq_trigger(irq: u8) {
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COUNTS.lock()[irq as usize] += 1;
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WAITS.call_once(init_waits)[irq as usize].notify();
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context::event::trigger(IRQ_SCHEME_ID.load(Ordering::SeqCst), irq as usize, EVENT_READ, mem::size_of::<usize>());
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}
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pub struct IrqScheme;
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impl Scheme for IrqScheme {
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fn open(&self, path: &[u8], _flags: usize, uid: u32, _gid: u32) -> Result<usize> {
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if uid == 0 {
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let path_str = str::from_utf8(path).or(Err(Error::new(ENOENT)))?;
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let id = path_str.parse::<usize>().or(Err(Error::new(ENOENT)))?;
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if id < COUNTS.lock().len() {
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Ok(id)
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} else {
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Err(Error::new(ENOENT))
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}
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} else {
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Err(Error::new(EACCES))
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}
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}
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fn dup(&self, file: usize) -> Result<usize> {
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Ok(file)
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}
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fn read(&self, file: usize, buffer: &mut [u8]) -> Result<usize> {
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// Ensures that the length of the buffer is larger than the size of a usize
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if buffer.len() >= mem::size_of::<usize>() {
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loop {
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let ack = ACKS.lock()[file];
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let current = COUNTS.lock()[file];
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if ack != current {
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// Safe if the length of the buffer is larger than the size of a usize
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assert!(buffer.len() >= mem::size_of::<usize>());
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unsafe { *(buffer.as_mut_ptr() as *mut usize) = current; }
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return Ok(mem::size_of::<usize>());
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} else {
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WAITS.call_once(init_waits)[file].wait();
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}
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}
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} else {
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Err(Error::new(EINVAL))
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}
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}
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fn write(&self, file: usize, buffer: &[u8]) -> Result<usize> {
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if buffer.len() >= mem::size_of::<usize>() {
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assert!(buffer.len() >= mem::size_of::<usize>());
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let ack = unsafe { *(buffer.as_ptr() as *const usize) };
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let current = COUNTS.lock()[file];
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if ack == current {
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ACKS.lock()[file] = ack;
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unsafe { acknowledge(file); }
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Ok(mem::size_of::<usize>())
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} else {
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Ok(0)
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}
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} else {
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Err(Error::new(EINVAL))
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}
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}
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fn fevent(&self, file: usize, _flags: usize) -> Result<usize> {
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Ok(file)
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}
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fn fsync(&self, _file: usize) -> Result<usize> {
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Ok(0)
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}
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fn close(&self, _file: usize) -> Result<usize> {
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Ok(0)
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}
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}
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