1 files changed, 89 insertions, 0 deletions
diff --git a/third_party/rust/redox_syscall/src/io/pio.rs b/third_party/rust/redox_syscall/src/io/pio.rs
new file mode 100644
index 0000000000..91ae310b62
--- /dev/null
+++ b/third_party/rust/redox_syscall/src/io/pio.rs
@@ -0,0 +1,89 @@
+use core::marker::PhantomData;
+
+use super::io::Io;
+
+/// Generic PIO
+#[derive(Copy, Clone)]
+pub struct Pio<T> {
+    port: u16,
+    value: PhantomData<T>,
+}
+
+impl<T> Pio<T> {
+    /// Create a PIO from a given port
+    pub const fn new(port: u16) -> Self {
+        Pio::<T> {
+            port: port,
+            value: PhantomData,
+        }
+    }
+}
+
+/// Read/Write for byte PIO
+impl Io for Pio<u8> {
+    type Value = u8;
+
+    /// Read
+    #[inline(always)]
+    fn read(&self) -> u8 {
+        let value: u8;
+        unsafe {
+            asm!("in $0, $1" : "={al}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
+        }
+        value
+    }
+
+    /// Write
+    #[inline(always)]
+    fn write(&mut self, value: u8) {
+        unsafe {
+            asm!("out $1, $0" : : "{al}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
+        }
+    }
+}
+
+/// Read/Write for word PIO
+impl Io for Pio<u16> {
+    type Value = u16;
+
+    /// Read
+    #[inline(always)]
+    fn read(&self) -> u16 {
+        let value: u16;
+        unsafe {
+            asm!("in $0, $1" : "={ax}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
+        }
+        value
+    }
+
+    /// Write
+    #[inline(always)]
+    fn write(&mut self, value: u16) {
+        unsafe {
+            asm!("out $1, $0" : : "{ax}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
+        }
+    }
+}
+
+/// Read/Write for doubleword PIO
+impl Io for Pio<u32> {
+    type Value = u32;
+
+    /// Read
+    #[inline(always)]
+    fn read(&self) -> u32 {
+        let value: u32;
+        unsafe {
+            asm!("in $0, $1" : "={eax}"(value) : "{dx}"(self.port) : "memory" : "intel", "volatile");
+        }
+        value
+    }
+
+    /// Write
+    #[inline(always)]
+    fn write(&mut self, value: u32) {
+        unsafe {
+            asm!("out $1, $0" : : "{eax}"(value), "{dx}"(self.port) : "memory" : "intel", "volatile");
+        }
+    }
+}