projects/linux·blob master · refs

142 lines · 3.4 KiB

1// SPDX-License-Identifier: GPL-2.0
2
3//! Rust DMA api test (based on QEMU's `pci-testdev`).
4//!
5//! To make this driver probe, QEMU must be run with `-device pci-testdev`.
6
7use kernel::{
8 device::Core,
9 dma::{
10 Coherent,
11 DataDirection,
12 Device,
13 DmaMask, //
14 },
15 io::{
16 io_project,
17 io_read,
18 Io, //
19 },
20 page,
21 pci,
22 prelude::*,
23 scatterlist::{
24 Owned,
25 SGTable, //
26 },
27 sync::aref::ARef, //
28};
29
30#[pin_data(PinnedDrop)]
31struct DmaSampleDriver {
32 pdev: ARef<pci::Device>,
33 ca: Coherent<[MyStruct]>,
34 #[pin]
35 sgt: SGTable<Owned<VVec<u8>>>,
36}
37
38const TEST_VALUES: [(u32, u32); 5] = [
39 (0xa, 0xb),
40 (0xc, 0xd),
41 (0xe, 0xf),
42 (0xab, 0xba),
43 (0xcd, 0xef),
44];
45
46#[derive(FromBytes, IntoBytes)]
47struct MyStruct {
48 h: u32,
49 b: u32,
50}
51
52impl MyStruct {
53 fn new(h: u32, b: u32) -> Self {
54 Self { h, b }
55 }
56}
57// SAFETY: All bit patterns are acceptable values for `MyStruct`.
58unsafe impl kernel::transmute::AsBytes for MyStruct {}
59// SAFETY: Instances of `MyStruct` have no uninitialized portions.
60unsafe impl kernel::transmute::FromBytes for MyStruct {}
61
62kernel::pci_device_table!(
63 PCI_TABLE,
64 <DmaSampleDriver as pci::Driver>::IdInfo,
65 [(pci::DeviceId::from_id(pci::Vendor::REDHAT, 0x5), ())]
66);
67
68impl pci::Driver for DmaSampleDriver {
69 type IdInfo = ();
70 type Data<'bound> = Self;
71 const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
72
73 fn probe<'bound>(
74 pdev: &'bound pci::Device<Core<'_>>,
75 _info: Option<&'bound Self::IdInfo>,
76 ) -> impl PinInit<Self, Error> + 'bound {
77 pin_init::pin_init_scope(move || {
78 dev_info!(pdev, "Probe DMA test driver.\n");
79
80 let mask = DmaMask::new::<64>();
81
82 // SAFETY: There are no concurrent calls to DMA allocation and mapping primitives.
83 unsafe { pdev.dma_set_mask_and_coherent(mask)? };
84
85 let ca: Coherent<[MyStruct]> =
86 Coherent::zeroed_slice(pdev.as_ref(), TEST_VALUES.len(), GFP_KERNEL)?;
87
88 for (i, value) in TEST_VALUES.into_iter().enumerate() {
89 io_project!(ca, [panic: i]).copy_write(MyStruct::new(value.0, value.1));
90 }
91
92 let size = 4 * page::PAGE_SIZE;
93 let pages = VVec::with_capacity(size, GFP_KERNEL)?;
94
95 let sgt = SGTable::new(pdev.as_ref(), pages, DataDirection::ToDevice, GFP_KERNEL);
96
97 Ok(try_pin_init!(Self {
98 pdev: pdev.into(),
99 ca,
100 sgt <- sgt,
101 }))
102 })
103 }
104}
105
106impl DmaSampleDriver {
107 fn check_dma(&self) {
108 for (i, value) in TEST_VALUES.into_iter().enumerate() {
109 let val0 = io_read!(self.ca, [panic: i].h);
110 let val1 = io_read!(self.ca, [panic: i].b);
111
112 assert_eq!(val0, value.0);
113 assert_eq!(val1, value.1);
114 }
115 }
116}
117
118#[pinned_drop]
119impl PinnedDrop for DmaSampleDriver {
120 fn drop(self: Pin<&mut Self>) {
121 dev_info!(self.pdev, "Unload DMA test driver.\n");
122
123 self.check_dma();
124
125 for (i, entry) in self.sgt.iter().enumerate() {
126 dev_info!(
127 self.pdev,
128 "Entry[{}]: DMA address: {:#x}",
129 i,
130 entry.dma_address(),
131 );
132 }
133 }
134}
135
136kernel::module_pci_driver! {
137 type: DmaSampleDriver,
138 name: "rust_dma",
139 authors: ["Abdiel Janulgue"],
140 description: "Rust DMA test",
141 license: "GPL v2",
142}