90 lines
2.4 KiB
Rust
90 lines
2.4 KiB
Rust
// SPDX-License-Identifier: MPL-2.0
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mod dma_coherent;
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mod dma_stream;
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use alloc::collections::BTreeSet;
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pub use dma_coherent::DmaCoherent;
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pub use dma_stream::{DmaDirection, DmaStream, DmaStreamSlice};
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use inherit_methods_macro::inherit_methods;
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use spin::Once;
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use super::Paddr;
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use crate::{arch::iommu::has_iommu, mm::PAGE_SIZE, sync::SpinLock};
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/// If a device performs DMA to read or write system
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/// memory, the addresses used by the device are device addresses.
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/// Daddr can distinguish the address space used by cpu side and
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/// the address space used by device side.
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pub type Daddr = usize;
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#[derive(PartialEq)]
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pub enum DmaType {
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Direct,
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Iommu,
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}
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#[derive(Debug)]
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pub enum DmaError {
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InvalidArgs,
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AlreadyMapped,
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}
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/// Has mapped address in the device address space.
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pub trait HasDaddr {
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/// Get the base address of the mapping in the
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/// device address space.
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fn daddr(&self) -> Daddr;
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}
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#[inherit_methods(from = "(**self)")]
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impl<T: HasDaddr> HasDaddr for &T {
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fn daddr(&self) -> Daddr;
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}
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/// Set of all physical addresses with dma mapping.
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static DMA_MAPPING_SET: Once<SpinLock<BTreeSet<Paddr>>> = Once::new();
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pub fn dma_type() -> DmaType {
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if has_iommu() {
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DmaType::Iommu
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} else {
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DmaType::Direct
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}
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}
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pub fn init() {
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DMA_MAPPING_SET.call_once(|| SpinLock::new(BTreeSet::new()));
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}
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/// Check whether the physical addresses has dma mapping.
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/// Fail if they have been mapped, otherwise insert them.
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fn check_and_insert_dma_mapping(start_paddr: Paddr, num_pages: usize) -> bool {
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let mut mapping_set = DMA_MAPPING_SET.get().unwrap().lock_irq_disabled();
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// Ensure that the addresses used later will not overflow
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start_paddr.checked_add(num_pages * PAGE_SIZE).unwrap();
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for i in 0..num_pages {
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let paddr = start_paddr + (i * PAGE_SIZE);
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if mapping_set.contains(&paddr) {
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return false;
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}
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}
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for i in 0..num_pages {
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let paddr = start_paddr + (i * PAGE_SIZE);
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mapping_set.insert(paddr);
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}
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true
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}
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/// Remove a physical address from the dma mapping set.
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fn remove_dma_mapping(start_paddr: Paddr, num_pages: usize) {
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let mut mapping_set = DMA_MAPPING_SET.get().unwrap().lock_irq_disabled();
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// Ensure that the addresses used later will not overflow
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start_paddr.checked_add(num_pages * PAGE_SIZE).unwrap();
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for i in 0..num_pages {
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let paddr = start_paddr + (i * PAGE_SIZE);
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mapping_set.remove(&paddr);
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}
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}
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