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