xref: /linux/drivers/gpu/nova-core/driver.rs (revision 46f651d88662ef931555cd135f09382af206295a)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 use kernel::{
4     auxiliary,
5     device::Core,
6     devres::Devres,
7     dma::Device,
8     dma::DmaMask,
9     pci,
10     pci::{
11         Class,
12         ClassMask,
13         Vendor, //
14     },
15     prelude::*,
16     sizes::SZ_16M,
17     sync::{
18         atomic::{
19             Atomic,
20             Relaxed, //
21         },
22         Arc,
23     },
24 };
25 
26 use crate::gpu::Gpu;
27 
28 /// Counter for generating unique auxiliary device IDs.
29 static AUXILIARY_ID_COUNTER: Atomic<u32> = Atomic::new(0);
30 
31 #[pin_data]
32 pub(crate) struct NovaCore {
33     #[pin]
34     pub(crate) gpu: Gpu,
35     _reg: Devres<auxiliary::Registration<()>>,
36 }
37 
38 const BAR0_SIZE: usize = SZ_16M;
39 
40 // For now we only support Ampere which can use up to 47-bit DMA addresses.
41 //
42 // TODO: Add an abstraction for this to support newer GPUs which may support
43 // larger DMA addresses. Limiting these GPUs to smaller address widths won't
44 // have any adverse affects, unless installed on systems which require larger
45 // DMA addresses. These systems should be quite rare.
46 const GPU_DMA_BITS: u32 = 47;
47 
48 pub(crate) type Bar0 = pci::Bar<BAR0_SIZE>;
49 
50 kernel::pci_device_table!(
51     PCI_TABLE,
52     MODULE_PCI_TABLE,
53     <NovaCore as pci::Driver>::IdInfo,
54     [
55         // Modern NVIDIA GPUs will show up as either VGA or 3D controllers.
56         (
57             pci::DeviceId::from_class_and_vendor(
58                 Class::DISPLAY_VGA,
59                 ClassMask::ClassSubclass,
60                 Vendor::NVIDIA
61             ),
62             ()
63         ),
64         (
65             pci::DeviceId::from_class_and_vendor(
66                 Class::DISPLAY_3D,
67                 ClassMask::ClassSubclass,
68                 Vendor::NVIDIA
69             ),
70             ()
71         ),
72     ]
73 );
74 
75 impl pci::Driver for NovaCore {
76     type IdInfo = ();
77     type Data<'bound> = Self;
78     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
79 
80     fn probe<'bound>(
81         pdev: &'bound pci::Device<Core<'_>>,
82         _info: &'bound Self::IdInfo,
83     ) -> impl PinInit<Self, Error> + 'bound {
84         pin_init::pin_init_scope(move || {
85             dev_dbg!(pdev, "Probe Nova Core GPU driver.\n");
86 
87             pdev.enable_device_mem()?;
88             pdev.set_master();
89 
90             // SAFETY: No concurrent DMA allocations or mappings can be made because
91             // the device is still being probed and therefore isn't being used by
92             // other threads of execution.
93             unsafe { pdev.dma_set_mask_and_coherent(DmaMask::new::<GPU_DMA_BITS>())? };
94 
95             let bar = Arc::pin_init(
96                 pdev.iomap_region_sized::<BAR0_SIZE>(0, c"nova-core/bar0"),
97                 GFP_KERNEL,
98             )?;
99 
100             Ok(try_pin_init!(Self {
101                 gpu <- Gpu::new(pdev, bar.clone(), bar.access(pdev.as_ref())?),
102                 _reg: auxiliary::Registration::new(
103                     pdev.as_ref(),
104                     c"nova-drm",
105                     // TODO[XARR]: Use XArray or perhaps IDA for proper ID allocation/recycling. For
106                     // now, use a simple atomic counter that never recycles IDs.
107                     AUXILIARY_ID_COUNTER.fetch_add(1, Relaxed),
108                     crate::MODULE_NAME,
109                     (),
110                 )?,
111             }))
112         })
113     }
114 
115     fn unbind<'bound>(pdev: &'bound pci::Device<Core<'_>>, this: Pin<&Self>) {
116         this.gpu.unbind(pdev.as_ref());
117     }
118 }
119