refactor(virtqueue): remove MemDescrId newtype

Author: mkroening

src/drivers/virtio/virtqueue/mod.rs

@@ -512,30 +512,26 @@ pub enum BufferType {
 	Indirect,
 }
 
-/// A newtype for descriptor ids, for better readability.
-#[derive(Clone, Copy)]
-struct MemDescrId(pub u16);
-
 /// MemPool allows to easily control, request and provide memory for Virtqueues.
 ///
 /// The struct is initialized with a limit of free running "tracked"
 /// memory descriptor ids. As Virtqueus do only allow a limited amount of descriptors in their queue,
 /// the independent queues, can control the number of descriptors by this.
 struct MemPool {
-	pool: Vec<MemDescrId>,
+	pool: Vec<u16>,
 	limit: u16,
 }
 
 impl MemPool {
 	/// Returns a given id to the id pool
-	fn ret_id(&mut self, id: MemDescrId) {
+	fn ret_id(&mut self, id: u16) {
 		self.pool.push(id);
 	}
 
 	/// Returns a new instance, with a pool of the specified size.
 	fn new(size: u16) -> MemPool {
 		MemPool {
-			pool: (0..size).map(MemDescrId).collect(),
+			pool: (0..size).collect(),
 			limit: size,
 		}
 	}

src/drivers/virtio/virtqueue/packed.rs

@@ -23,8 +23,7 @@ use super::super::transport::mmio::{ComCfg, NotifCfg, NotifCtrl};
 use super::super::transport::pci::{ComCfg, NotifCfg, NotifCtrl};
 use super::error::VirtqError;
 use super::{
-	AvailBufferToken, BufferType, MemDescrId, MemPool, TransferToken, UsedBufferToken, Virtq,
-	VirtqPrivate,
+	AvailBufferToken, BufferType, MemPool, TransferToken, UsedBufferToken, Virtq, VirtqPrivate,
 };
 use crate::arch::mm::paging::{BasePageSize, PageSize};
 use crate::mm::device_alloc::DeviceAlloc;
@@ -214,11 +213,11 @@ impl DescriptorRing {
 		&mut self,
 		raw_tkn: TransferToken<pvirtq::Desc>,
 		start: u16,
-		buff_id: MemDescrId,
+		buff_id: u16,
 		first_flags: DescF,
 	) {
 		// provide reference, in order to let TransferToken know upon finish.
-		self.tkn_ref_ring[usize::from(buff_id.0)] = Some(raw_tkn);
+		self.tkn_ref_ring[usize::from(buff_id)] = Some(raw_tkn);
 		// The driver performs a suitable memory barrier to ensure the device sees the updated descriptor table and available ring before the next step.
 		// See Virtio specification v1.1. - 2.7.21
 		fence(Ordering::SeqCst);
@@ -304,7 +303,7 @@ impl ReadCtrl<'_> {
 			for _ in 0..tkn.num_consuming_descr() {
 				self.incrmt();
 			}
-			self.desc_ring.mem_pool.ret_id(MemDescrId(buff_id));
+			self.desc_ring.mem_pool.ret_id(buff_id);
 
 			Some((tkn, write_len))
 		} else {
@@ -341,7 +340,7 @@ struct WriteCtrl<'a> {
 	/// The [pvirtq::Desc::flags] value for the first descriptor, the write of which is deferred.
 	first_flags: DescF,
 	/// Buff ID of this write
-	buff_id: MemDescrId,
+	buff_id: u16,
 
 	desc_ring: &'a mut DescriptorRing,
 }
@@ -371,7 +370,7 @@ impl WriteCtrl<'_> {
 
 	/// Completes the descriptor flags and id, and writes into the queue at the correct position.
 	fn write_desc(&mut self, mut incomplete_desc: pvirtq::Desc) {
-		incomplete_desc.id = self.buff_id.0.into();
+		incomplete_desc.id = self.buff_id.into();
 		if self.start == self.position {
 			// We save what the flags value for the first descriptor will be to be able
 			// to write it later when all the other descriptors are written (so that

src/drivers/virtio/virtqueue/split.rs

@@ -58,7 +58,7 @@ impl DescrRing {
 		if let Some(ctrl_desc) = tkn.ctrl_desc.as_ref() {
 			let descriptor = SplitVq::indirect_desc(ctrl_desc.as_ref());
 
-			index = self.mem_pool.pool.pop().ok_or(VirtqError::NoDescrAvail)?.0;
+			index = self.mem_pool.pool.pop().ok_or(VirtqError::NoDescrAvail)?;
 			self.descr_table_mut()[usize::from(index)] = MaybeUninit::new(descriptor);
 		} else {
 			let mut rev_all_desc_iter = SplitVq::descriptor_iter(&tkn.buff_tkn)?.rev();
@@ -68,14 +68,14 @@ impl DescrRing {
 				// If the [AvailBufferToken] is empty, we panic
 				let descriptor = rev_all_desc_iter.next().unwrap();
 
-				index = self.mem_pool.pool.pop().ok_or(VirtqError::NoDescrAvail)?.0;
+				index = self.mem_pool.pool.pop().ok_or(VirtqError::NoDescrAvail)?;
 				self.descr_table_mut()[usize::from(index)] = MaybeUninit::new(descriptor);
 			}
 			for mut descriptor in rev_all_desc_iter {
 				// We have not updated `index` yet, so it is at this point the index of the previous descriptor that had been written.
 				descriptor.next = le16::from(index);
 
-				index = self.mem_pool.pool.pop().ok_or(VirtqError::NoDescrAvail)?.0;
+				index = self.mem_pool.pool.pop().ok_or(VirtqError::NoDescrAvail)?;
 				self.descr_table_mut()[usize::from(index)] = MaybeUninit::new(descriptor);
 			}
 			// At this point, `index` is the index of the last element of the reversed iterator,
@@ -111,7 +111,7 @@ impl DescrRing {
 		// We return the indices of the now freed ring slots back to `mem_pool.`
 		let mut id_ret_idx = u16::try_from(used_elem.id.to_ne()).unwrap();
 		loop {
-			self.mem_pool.ret_id(super::MemDescrId(id_ret_idx));
+			self.mem_pool.ret_id(id_ret_idx);
 			let cur_chain_elem =
 				unsafe { self.descr_table_mut()[usize::from(id_ret_idx)].assume_init() };
 			if cur_chain_elem.flags.contains(virtq::DescF::NEXT) {