rust: dma: require a bound device

Require the Bound device context to be able to create new
dma::CoherentAllocation instances.

DMA memory allocations are only valid to be created for bound devices.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Danilo Krummrich <[email protected]>

Author: Danilo Krummrich

rust/kernel/dma.rs

@@ -6,7 +6,7 @@
 
 use crate::{
     bindings, build_assert,
-    device::Device,
+    device::{Bound, Device},
     error::code::*,
     error::Result,
     transmute::{AsBytes, FromBytes},
@@ -22,10 +22,10 @@ use crate::{
 /// # Examples
 ///
 /// ```
-/// use kernel::device::Device;
+/// # use kernel::device::{Bound, Device};
 /// use kernel::dma::{attrs::*, CoherentAllocation};
 ///
-/// # fn test(dev: &Device) -> Result {
+/// # fn test(dev: &Device<Bound>) -> Result {
 /// let attribs = DMA_ATTR_FORCE_CONTIGUOUS | DMA_ATTR_NO_WARN;
 /// let c: CoherentAllocation<u64> =
 ///     CoherentAllocation::alloc_attrs(dev, 4, GFP_KERNEL, attribs)?;
@@ -143,16 +143,16 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
     /// # Examples
     ///
     /// ```
-    /// use kernel::device::Device;
+    /// # use kernel::device::{Bound, Device};
     /// use kernel::dma::{attrs::*, CoherentAllocation};
     ///
-    /// # fn test(dev: &Device) -> Result {
+    /// # fn test(dev: &Device<Bound>) -> Result {
     /// let c: CoherentAllocation<u64> =
     ///     CoherentAllocation::alloc_attrs(dev, 4, GFP_KERNEL, DMA_ATTR_NO_WARN)?;
     /// # Ok::<(), Error>(()) }
     /// ```
     pub fn alloc_attrs(
-        dev: &Device,
+        dev: &Device<Bound>,
         count: usize,
         gfp_flags: kernel::alloc::Flags,
         dma_attrs: Attrs,
@@ -194,7 +194,7 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
     /// Performs the same functionality as [`CoherentAllocation::alloc_attrs`], except the
     /// `dma_attrs` is 0 by default.
     pub fn alloc_coherent(
-        dev: &Device,
+        dev: &Device<Bound>,
         count: usize,
         gfp_flags: kernel::alloc::Flags,
     ) -> Result<CoherentAllocation<T>> {