Move Io/Pio/Mmio from redox_syscall to common

* Fix Mmio repr from transparent to packed. * Rename Mmio::from to Mmio::new. * Remove dead imports around affected code. * Minor formatting.
2024-09-27 23:31:03 +02:00
parent ea5ccbc84d
commit d2c82add9d
50 changed files with 421 additions and 59 deletions
@@ -0,0 +1,95 @@
+use core::{
+    cmp::PartialEq,
+    ops::{BitAnd, BitOr, Not},
+};
+
+mod mmio;
+mod pio;
+
+pub use mmio::*;
+pub use pio::*;
+
+/// IO abstraction
+pub trait Io {
+    /// Value type for IO, usually some unsigned number
+    type Value: Copy
+        + PartialEq
+        + BitAnd<Output = Self::Value>
+        + BitOr<Output = Self::Value>
+        + Not<Output = Self::Value>;
+
+    /// Read the underlying valu2e
+    fn read(&self) -> Self::Value;
+    /// Write the underlying value
+    fn write(&mut self, value: Self::Value);
+
+    /// Check whether the underlying value contains bit flags
+    #[inline(always)]
+    fn readf(&self, flags: Self::Value) -> bool {
+        (self.read() & flags) as Self::Value == flags
+    }
+
+    /// Enable or disable specific bit flags
+    #[inline(always)]
+    fn writef(&mut self, flags: Self::Value, value: bool) {
+        let tmp: Self::Value = match value {
+            true => self.read() | flags,
+            false => self.read() & !flags,
+        };
+        self.write(tmp);
+    }
+}
+
+/// Read-only IO
+#[repr(transparent)]
+pub struct ReadOnly<I> {
+    inner: I,
+}
+
+impl<I: Io> ReadOnly<I> {
+    /// Wraps IO
+    pub const fn new(inner: I) -> ReadOnly<I> {
+        ReadOnly { inner }
+    }
+}
+
+impl<I: Io> ReadOnly<I> {
+    /// Calls [Io::read]
+    #[inline(always)]
+    pub fn read(&self) -> I::Value {
+        self.inner.read()
+    }
+
+    /// Calls [Io::readf]
+    #[inline(always)]
+    pub fn readf(&self, flags: I::Value) -> bool {
+        self.inner.readf(flags)
+    }
+}
+
+#[repr(transparent)]
+/// Write-only IO
+pub struct WriteOnly<I> {
+    inner: I,
+}
+
+impl<I: Io> WriteOnly<I> {
+    /// Wraps IO
+    pub const fn new(inner: I) -> WriteOnly<I> {
+        WriteOnly { inner }
+    }
+}
+
+impl<I: Io> WriteOnly<I> {
+    /// Calls [Io::write]
+    #[inline(always)]
+    pub fn write(&mut self, value: I::Value) {
+        self.inner.write(value)
+    }
+
+    #[inline(always)]
+    /// Calls [Io::writef]
+    pub fn writef(&mut self, flags: I::Value, value: bool) {
+        self.inner.writef(flags, value)
+    }
+}
@@ -0,0 +1,169 @@
+use core::{mem::MaybeUninit, ptr};
+
+use super::Io;
+
+/// MMIO abstraction
+#[repr(packed)]
+pub struct Mmio<T> {
+    value: MaybeUninit<T>,
+}
+
+impl<T> Mmio<T> {
+    /// Creates a zeroed instance
+    pub unsafe fn zeroed() -> Self {
+        Self {
+            value: MaybeUninit::zeroed(),
+        }
+    }
+
+    /// Creates an unitialized instance
+    pub unsafe fn uninit() -> Self {
+        Self {
+            value: MaybeUninit::uninit(),
+        }
+    }
+
+    /// Creates a new instance
+    pub const fn new(value: T) -> Self {
+        Self {
+            value: MaybeUninit::new(value),
+        }
+    }
+}
+
+// Generic implementation (WARNING: requires aligned pointers!)
+#[cfg(not(any(target_arch = "x86", target_arch = "x86_64")))]
+impl<T> Io for Mmio<T>
+where
+    T: Copy + PartialEq + BitAnd<Output = T> + BitOr<Output = T> + Not<Output = T>,
+{
+    type Value = T;
+
+    fn read(&self) -> T {
+        unsafe { ptr::read_volatile(ptr::addr_of!(self.value).cast::<T>()) }
+    }
+
+    fn write(&mut self, value: T) {
+        unsafe { ptr::write_volatile(ptr::addr_of_mut!(self.value).cast::<T>(), value) };
+    }
+}
+
+// x86 u8 implementation
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+impl Io for Mmio<u8> {
+    type Value = u8;
+
+    fn read(&self) -> Self::Value {
+        unsafe {
+            let value: Self::Value;
+            let ptr: *const Self::Value = ptr::addr_of!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov {}, [{}]",
+                out(reg_byte) value,
+                in(reg) ptr
+            );
+            value
+        }
+    }
+
+    fn write(&mut self, value: Self::Value) {
+        unsafe {
+            let ptr: *mut Self::Value = ptr::addr_of_mut!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov [{}], {}",
+                in(reg) ptr,
+                in(reg_byte) value,
+            );
+        }
+    }
+}
+
+// x86 u16 implementation
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+impl Io for Mmio<u16> {
+    type Value = u16;
+
+    fn read(&self) -> Self::Value {
+        unsafe {
+            let value: Self::Value;
+            let ptr: *const Self::Value = ptr::addr_of!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov {:x}, [{}]",
+                out(reg) value,
+                in(reg) ptr
+            );
+            value
+        }
+    }
+
+    fn write(&mut self, value: Self::Value) {
+        unsafe {
+            let ptr: *mut Self::Value = ptr::addr_of_mut!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov [{}], {:x}",
+                in(reg) ptr,
+                in(reg) value,
+            );
+        }
+    }
+}
+
+// x86 u32 implementation
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+impl Io for Mmio<u32> {
+    type Value = u32;
+
+    fn read(&self) -> Self::Value {
+        unsafe {
+            let value: Self::Value;
+            let ptr: *const Self::Value = ptr::addr_of!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov {:e}, [{}]",
+                out(reg) value,
+                in(reg) ptr
+            );
+            value
+        }
+    }
+
+    fn write(&mut self, value: Self::Value) {
+        unsafe {
+            let ptr: *mut Self::Value = ptr::addr_of_mut!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov [{}], {:e}",
+                in(reg) ptr,
+                in(reg) value,
+            );
+        }
+    }
+}
+
+// x86 u64 implementation (x86_64 only)
+#[cfg(target_arch = "x86_64")]
+impl Io for Mmio<u64> {
+    type Value = u64;
+
+    fn read(&self) -> Self::Value {
+        unsafe {
+            let value: Self::Value;
+            let ptr: *const Self::Value = ptr::addr_of!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov {:r}, [{}]",
+                out(reg) value,
+                in(reg) ptr
+            );
+            value
+        }
+    }
+
+    fn write(&mut self, value: Self::Value) {
+        unsafe {
+            let ptr: *mut Self::Value = ptr::addr_of_mut!(self.value).cast::<Self::Value>();
+            core::arch::asm!(
+                "mov [{}], {:r}",
+                in(reg) ptr,
+                in(reg) value,
+            );
+        }
+    }
+}
@@ -0,0 +1,89 @@
+use core::{arch::asm, marker::PhantomData};
+
+use super::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,
+            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 al, dx", in("dx") self.port, out("al") value, options(nostack, nomem, preserves_flags));
+        }
+        value
+    }
+
+    /// Write
+    #[inline(always)]
+    fn write(&mut self, value: u8) {
+        unsafe {
+            asm!("out dx, al", in("dx") self.port, in("al") value, options(nostack, nomem, preserves_flags));
+        }
+    }
+}
+
+/// 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 ax, dx", in("dx") self.port, out("ax") value, options(nostack, nomem, preserves_flags));
+        }
+        value
+    }
+
+    /// Write
+    #[inline(always)]
+    fn write(&mut self, value: u16) {
+        unsafe {
+            asm!("out dx, ax", in("dx") self.port, in("ax") value, options(nostack, nomem, preserves_flags));
+        }
+    }
+}
+
+/// 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 eax, dx", in("dx") self.port, out("eax") value, options(nostack, nomem, preserves_flags));
+        }
+        value
+    }
+
+    /// Write
+    #[inline(always)]
+    fn write(&mut self, value: u32) {
+        unsafe {
+            asm!("out dx, eax", in("dx") self.port, in("eax") value, options(nostack, nomem, preserves_flags));
+        }
+    }
+}
@@ -12,6 +12,8 @@ use syscall::PAGE_SIZE;

 /// The Direct Memory Access (DMA) API for drivers
 pub mod dma;
+/// MMIO utilities
+pub mod io;
 mod logger;
 /// The Scatter Gather List (SGL) API for drivers.
 pub mod sgl;
@@ -128,7 +130,7 @@ pub unsafe fn physmap(
    // TODO: arraystring?

    //Return an error rather than potentially crash the kernel.
-    if(base_phys == 0) {
+    if base_phys == 0 {
        return Err(Error::new(EINVAL));
    }