Remove Dma module.

src/io/dma.rs

@@ -1,219 +0,0 @@
-use core::mem::{self, MaybeUninit};
-use core::ops::{Deref, DerefMut};
-use core::{ptr, slice};
-
-use crate::Result;
-use crate::{PartialAllocStrategy, PhysallocFlags, PhysmapFlags};
-use crate::arch::PAGE_SIZE;
-
-/// An RAII guard of a physical memory allocation. Currently all physically allocated memory are
-/// page-aligned and take up at least 4k of space (on x86_64).
-#[derive(Debug)]
-pub struct PhysBox {
-    address: usize,
-    size: usize
-}
-
-const fn round_up(x: usize) -> usize {
-    (x + PAGE_SIZE - 1) / PAGE_SIZE * PAGE_SIZE
-}
-fn assert_aligned(x: usize) {
-    assert_eq!(x % PAGE_SIZE, 0);
-}
-
-#[cfg(target_arch = "aarch64")]
-fn physmap_flags() -> PhysmapFlags {
-    // aarch64 currently must map DMA memory without caching to ensure coherence
-    crate::PHYSMAP_NO_CACHE | crate::PHYSMAP_WRITE
-}
-
-#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
-fn physmap_flags() -> PhysmapFlags {
-    // x86 ensures cache coherence with DMA memory
-    crate::PHYSMAP_WRITE
-}
-
-impl PhysBox {
-    /// Construct a PhysBox from an address and a size. The address must be page-aligned, and the
-    /// size must similarly be a multiple of the page size.
-    ///
-    /// # Safety
-    /// This function is unsafe because when dropping, Self has to a valid allocation.
-    pub unsafe fn from_raw_parts(address: usize, size: usize) -> Self {
-        assert_aligned(address);
-        assert_aligned(size);
-
-        Self {
-            address,
-            size,
-        }
-    }
-
-    /// Retrieve the byte address in physical memory, of this allocation.
-    pub fn address(&self) -> usize {
-        self.address
-    }
-
-    /// Retrieve the size in bytes of the alloc.
-    pub fn size(&self) -> usize {
-        self.size
-    }
-
-    /// Allocate physical memory that must reside in 32-bit space.
-    pub fn new_in_32bit_space(size: usize) -> Result<Self> {
-        Self::new_with_flags(size, PhysallocFlags::SPACE_32)
-    }
-
-    pub fn new_with_flags(size: usize, flags: PhysallocFlags) -> Result<Self> {
-        assert!(!flags.contains(PhysallocFlags::PARTIAL_ALLOC));
-        assert_aligned(size);
-
-        let address = unsafe { crate::physalloc2(size, flags.bits())? };
-        Ok(unsafe { Self::from_raw_parts(address, size) })
-    }
-
-    /// "Partially" allocate physical memory, in the sense that the allocation may be smaller than
-    /// expected, but still with a minimum limit. This is particularly useful when the physical
-    /// memory space is fragmented, and a device supports scatter-gather I/O. In that case, the
-    /// driver can optimistically request e.g. 1 alloc of 1 MiB, with the minimum of 512 KiB. If
-    /// that first allocation only returns half the size, the driver can do another allocation
-    /// and then let the device use both buffers.
-    pub fn new_partial_allocation(size: usize, flags: PhysallocFlags, strategy: Option<PartialAllocStrategy>, mut min: usize) -> Result<Self> {
-        assert_aligned(size);
-        debug_assert!(!(flags.contains(PhysallocFlags::PARTIAL_ALLOC) && strategy.is_none()));
-
-        let address = unsafe { crate::physalloc3(size, flags.bits() | strategy.map_or(0, |s| s as usize), &mut min)? };
-        Ok(unsafe { Self::from_raw_parts(address, size) })
-    }
-
-    pub fn new(size: usize) -> Result<Self> {
-        assert_aligned(size);
-
-        let address = unsafe { crate::physalloc(size)? };
-        Ok(unsafe { Self::from_raw_parts(address, size) })
-    }
-}
-
-impl Drop for PhysBox {
-    fn drop(&mut self) {
-        let _ = unsafe { crate::physfree(self.address, self.size) };
-    }
-}
-
-pub struct Dma<T: ?Sized> {
-    phys: PhysBox,
-    virt: *mut T,
-}
-
-impl<T> Dma<T> {
-    pub fn from_physbox_uninit(phys: PhysBox) -> Result<Dma<MaybeUninit<T>>> {
-        let virt = unsafe { crate::physmap(phys.address, phys.size, physmap_flags())? } as *mut MaybeUninit<T>;
-
-        Ok(Dma {
-            phys,
-            virt,
-        })
-    }
-    pub fn from_physbox_zeroed(phys: PhysBox) -> Result<Dma<MaybeUninit<T>>> {
-        let this = Self::from_physbox_uninit(phys)?;
-        unsafe { ptr::write_bytes(this.virt as *mut MaybeUninit<u8>, 0, this.phys.size) }
-        Ok(this)
-    }
-
-    pub fn from_physbox(phys: PhysBox, value: T) -> Result<Self> {
-        let this = Self::from_physbox_uninit(phys)?;
-
-        Ok(unsafe {
-            ptr::write(this.virt, MaybeUninit::new(value));
-            this.assume_init()
-        })
-    }
-
-    pub fn new(value: T) -> Result<Self> {
-        let phys = PhysBox::new(round_up(mem::size_of::<T>()))?;
-        Self::from_physbox(phys, value)
-    }
-    pub fn zeroed() -> Result<Dma<MaybeUninit<T>>> {
-        let phys = PhysBox::new(round_up(mem::size_of::<T>()))?;
-        Self::from_physbox_zeroed(phys)
-    }
-}
-
-impl<T> Dma<MaybeUninit<T>> {
-    pub unsafe fn assume_init(self) -> Dma<T> {
-        let &Dma { phys: PhysBox { address, size }, virt } = &self;
-        mem::forget(self);
-
-        Dma {
-            phys: PhysBox { address, size },
-            virt: virt as *mut T,
-        }
-    }
-}
-impl<T: ?Sized> Dma<T> {
-    pub fn physical(&self) -> usize {
-        self.phys.address()
-    }
-    pub fn size(&self) -> usize {
-        self.phys.size()
-    }
-    pub fn phys(&self) -> &PhysBox {
-        &self.phys
-    }
-}
-
-impl<T> Dma<[T]> {
-    pub fn from_physbox_uninit_unsized(phys: PhysBox, len: usize) -> Result<Dma<[MaybeUninit<T>]>> {
-        let max_len = phys.size() / mem::size_of::<T>();
-        assert!(len <= max_len);
-
-        Ok(Dma {
-            virt: unsafe { slice::from_raw_parts_mut(crate::physmap(phys.address, phys.size, physmap_flags())? as *mut MaybeUninit<T>, len) } as *mut [MaybeUninit<T>],
-            phys,
-        })
-    }
-    pub fn from_physbox_zeroed_unsized(phys: PhysBox, len: usize) -> Result<Dma<[MaybeUninit<T>]>> {
-        let this = Self::from_physbox_uninit_unsized(phys, len)?;
-        unsafe { ptr::write_bytes(this.virt as *mut MaybeUninit<u8>, 0, this.phys.size()) }
-        Ok(this)
-    }
-    /// Creates a new DMA buffer with a size only known at runtime.
-    /// ## Safety
-    /// * `T` must be properly aligned.
-    /// * `T` must be valid as zeroed (i.e. no NonNull pointers).
-    pub unsafe fn zeroed_unsized(count: usize) -> Result<Self> {
-        let phys = PhysBox::new(round_up(mem::size_of::<T>() * count))?;
-        Ok(Self::from_physbox_zeroed_unsized(phys, count)?.assume_init())
-    }
-}
-impl<T> Dma<[MaybeUninit<T>]> {
-    pub unsafe fn assume_init(self) -> Dma<[T]> {
-        let &Dma { phys: PhysBox { address, size }, virt } = &self;
-        mem::forget(self);
-
-        Dma {
-            phys: PhysBox { address, size },
-            virt: virt as *mut [T],
-        }
-    }
-}
-
-impl<T: ?Sized> Deref for Dma<T> {
-    type Target = T;
-    fn deref(&self) -> &T {
-        unsafe { &*self.virt }
-    }
-}
-
-impl<T: ?Sized> DerefMut for Dma<T> {
-    fn deref_mut(&mut self) -> &mut T {
-        unsafe { &mut *self.virt }
-    }
-}
-
-impl<T: ?Sized> Drop for Dma<T> {
-    fn drop(&mut self) {
-        unsafe { ptr::drop_in_place(self.virt) }
-        let _ = unsafe { crate::funmap(self.virt as *mut u8 as usize, self.phys.size) };
-    }
-}

src/io/mod.rs

@@ -1,13 +1,11 @@
 //! I/O functions
 
-pub use self::dma::*;
 pub use self::io::*;
 pub use self::mmio::*;
 
 #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 pub use self::pio::*;
 
-mod dma;
 mod io;
 mod mmio;