xref: /linux/drivers/gpu/nova-core/driver.rs (revision dc395c2831b59a90b4605ef38e6c6ef83cf8cc4f)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 use kernel::{
4     auxiliary,
5     device::Core,
6     dma::Device,
7     dma::DmaMask,
8     pci,
9     pci::{
10         Class,
11         ClassMask,
12         Vendor, //
13     },
14     prelude::*,
15     sizes::SZ_16M,
16     sync::atomic::{
17         Atomic,
18         Relaxed, //
19     },
20     types::ForLt,
21 };
22 
23 use crate::gpu::Gpu;
24 
25 /// Counter for generating unique auxiliary device IDs.
26 static AUXILIARY_ID_COUNTER: Atomic<u32> = Atomic::new(0);
27 
28 #[pin_data]
29 pub(crate) struct NovaCore<'bound> {
30     #[pin]
31     pub(crate) gpu: Gpu<'bound>,
32     bar: pci::Bar<'bound, BAR0_SIZE>,
33     #[allow(clippy::type_complexity)]
34     _reg: auxiliary::Registration<'bound, ForLt!(())>,
35 }
36 
37 pub(crate) struct NovaCoreDriver;
38 
39 const BAR0_SIZE: usize = SZ_16M;
40 
41 // For now we only support Ampere which can use up to 47-bit DMA addresses.
42 //
43 // TODO: Add an abstraction for this to support newer GPUs which may support
44 // larger DMA addresses. Limiting these GPUs to smaller address widths won't
45 // have any adverse affects, unless installed on systems which require larger
46 // DMA addresses. These systems should be quite rare.
47 const GPU_DMA_BITS: u32 = 47;
48 
49 pub(crate) type Bar0 = kernel::io::Mmio<BAR0_SIZE>;
50 
51 kernel::pci_device_table!(
52     PCI_TABLE,
53     MODULE_PCI_TABLE,
54     <NovaCoreDriver as pci::Driver>::IdInfo,
55     [
56         // Modern NVIDIA GPUs will show up as either VGA or 3D controllers.
57         (
58             pci::DeviceId::from_class_and_vendor(
59                 Class::DISPLAY_VGA,
60                 ClassMask::ClassSubclass,
61                 Vendor::NVIDIA
62             ),
63             ()
64         ),
65         (
66             pci::DeviceId::from_class_and_vendor(
67                 Class::DISPLAY_3D,
68                 ClassMask::ClassSubclass,
69                 Vendor::NVIDIA
70             ),
71             ()
72         ),
73     ]
74 );
75 
76 impl pci::Driver for NovaCoreDriver {
77     type IdInfo = ();
78     type Data<'bound> = NovaCore<'bound>;
79     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
80 
81     fn probe<'bound>(
82         pdev: &'bound pci::Device<Core<'_>>,
83         _info: &'bound Self::IdInfo,
84     ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound {
85         pin_init::pin_init_scope(move || {
86             dev_dbg!(pdev, "Probe Nova Core GPU driver.\n");
87 
88             pdev.enable_device_mem()?;
89             pdev.set_master();
90 
91             // SAFETY: No concurrent DMA allocations or mappings can be made because
92             // the device is still being probed and therefore isn't being used by
93             // other threads of execution.
94             unsafe { pdev.dma_set_mask_and_coherent(DmaMask::new::<GPU_DMA_BITS>())? };
95 
96             Ok(try_pin_init!(NovaCore {
97                 bar: pdev.iomap_region_sized::<BAR0_SIZE>(0, c"nova-core/bar0")?,
98                 // TODO: Use `&bar` self-referential pin-init syntax once available.
99                 //
100                 // SAFETY: `bar` is initialized before this expression is evaluated
101                 // (`try_pin_init!()` initializes fields in declaration order), lives at a pinned
102                 // stable address, and is dropped after `gpu` (struct field drop order).
103                 gpu <- Gpu::new(pdev, unsafe { &*core::ptr::from_ref(bar) }),
104                 _reg: auxiliary::Registration::new(
105                     pdev.as_ref(),
106                     c"nova-drm",
107                     // TODO[XARR]: Use XArray or perhaps IDA for proper ID allocation/recycling. For
108                     // now, use a simple atomic counter that never recycles IDs.
109                     AUXILIARY_ID_COUNTER.fetch_add(1, Relaxed),
110                     crate::MODULE_NAME,
111                     (),
112                 )?,
113             }))
114         })
115     }
116 }
117