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 
7 use kernel::{bindings, device::Core, dma::CoherentAllocation, pci, prelude::*, types::ARef};
8 
9 struct DmaSampleDriver {
10     pdev: ARef<pci::Device>,
11     ca: CoherentAllocation<MyStruct>,
12 }
13 
14 const TEST_VALUES: [(u32, u32); 5] = [
15     (0xa, 0xb),
16     (0xc, 0xd),
17     (0xe, 0xf),
18     (0xab, 0xba),
19     (0xcd, 0xef),
20 ];
21 
22 struct MyStruct {
23     h: u32,
24     b: u32,
25 }
26 
27 impl MyStruct {
new(h: u32, b: u32) -> Self28     fn new(h: u32, b: u32) -> Self {
29         Self { h, b }
30     }
31 }
32 // SAFETY: All bit patterns are acceptable values for `MyStruct`.
33 unsafe impl kernel::transmute::AsBytes for MyStruct {}
34 // SAFETY: Instances of `MyStruct` have no uninitialized portions.
35 unsafe impl kernel::transmute::FromBytes for MyStruct {}
36 
37 kernel::pci_device_table!(
38     PCI_TABLE,
39     MODULE_PCI_TABLE,
40     <DmaSampleDriver as pci::Driver>::IdInfo,
41     [(
42         pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, 0x5),
43         ()
44     )]
45 );
46 
47 impl pci::Driver for DmaSampleDriver {
48     type IdInfo = ();
49     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
50 
probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>>51     fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
52         dev_info!(pdev.as_ref(), "Probe DMA test driver.\n");
53 
54         let ca: CoherentAllocation<MyStruct> =
55             CoherentAllocation::alloc_coherent(pdev.as_ref(), TEST_VALUES.len(), GFP_KERNEL)?;
56 
57         || -> Result {
58             for (i, value) in TEST_VALUES.into_iter().enumerate() {
59                 kernel::dma_write!(ca[i] = MyStruct::new(value.0, value.1));
60             }
61 
62             Ok(())
63         }()?;
64 
65         let drvdata = KBox::new(
66             Self {
67                 pdev: pdev.into(),
68                 ca,
69             },
70             GFP_KERNEL,
71         )?;
72 
73         Ok(drvdata.into())
74     }
75 }
76 
77 impl Drop for DmaSampleDriver {
drop(&mut self)78     fn drop(&mut self) {
79         dev_info!(self.pdev.as_ref(), "Unload DMA test driver.\n");
80 
81         let _ = || -> Result {
82             for (i, value) in TEST_VALUES.into_iter().enumerate() {
83                 assert_eq!(kernel::dma_read!(self.ca[i].h), value.0);
84                 assert_eq!(kernel::dma_read!(self.ca[i].b), value.1);
85             }
86             Ok(())
87         }();
88     }
89 }
90 
91 kernel::module_pci_driver! {
92     type: DmaSampleDriver,
93     name: "rust_dma",
94     authors: ["Abdiel Janulgue"],
95     description: "Rust DMA test",
96     license: "GPL v2",
97 }
98