xref: /openbmc/qemu/rust/hw/core/src/sysbus.rs (revision 917ac07f9aef579b9538a81d45f45850aba42906)
1 // Copyright 2024 Red Hat, Inc.
2 // Author(s): Paolo Bonzini <pbonzini@redhat.com>
3 // SPDX-License-Identifier: GPL-2.0-or-later
4 
5 //! Bindings to access `sysbus` functionality from Rust.
6 
7 use std::ffi::CStr;
8 
9 pub use bindings::SysBusDeviceClass;
10 use common::Opaque;
11 use qom::{prelude::*, Owned};
12 use system::MemoryRegion;
13 use util::{Error, Result};
14 
15 use crate::{
16     bindings,
17     irq::{IRQState, InterruptSource},
18     qdev::{DeviceImpl, DeviceState},
19 };
20 
21 /// A safe wrapper around [`bindings::SysBusDevice`].
22 #[repr(transparent)]
23 #[derive(Debug, common::Wrapper)]
24 pub struct SysBusDevice(Opaque<bindings::SysBusDevice>);
25 
26 unsafe impl Send for SysBusDevice {}
27 unsafe impl Sync for SysBusDevice {}
28 
29 unsafe impl ObjectType for SysBusDevice {
30     type Class = SysBusDeviceClass;
31     const TYPE_NAME: &'static CStr =
32         unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_SYS_BUS_DEVICE) };
33 }
34 
35 qom_isa!(SysBusDevice: DeviceState, Object);
36 
37 // TODO: add virtual methods
38 pub trait SysBusDeviceImpl: DeviceImpl + IsA<SysBusDevice> {}
39 
40 impl SysBusDeviceClass {
41     /// Fill in the virtual methods of `SysBusDeviceClass` based on the
42     /// definitions in the `SysBusDeviceImpl` trait.
43     pub fn class_init<T: SysBusDeviceImpl>(self: &mut SysBusDeviceClass) {
44         self.parent_class.class_init::<T>();
45     }
46 }
47 
48 /// Trait for methods of [`SysBusDevice`] and its subclasses.
49 pub trait SysBusDeviceMethods: ObjectDeref
50 where
51     Self::Target: IsA<SysBusDevice>,
52 {
53     /// Expose a memory region to the board so that it can give it an address
54     /// in guest memory.  Note that the ordering of calls to `init_mmio` is
55     /// important, since whoever creates the sysbus device will refer to the
56     /// region with a number that corresponds to the order of calls to
57     /// `init_mmio`.
58     fn init_mmio(&self, iomem: &MemoryRegion) {
59         assert!(bql::is_locked());
60         unsafe {
61             bindings::sysbus_init_mmio(self.upcast().as_mut_ptr(), iomem.as_mut_ptr());
62         }
63     }
64 
65     /// Expose an interrupt source outside the device as a qdev GPIO output.
66     /// Note that the ordering of calls to `init_irq` is important, since
67     /// whoever creates the sysbus device will refer to the interrupts with
68     /// a number that corresponds to the order of calls to `init_irq`.
69     fn init_irq(&self, irq: &InterruptSource) {
70         assert!(bql::is_locked());
71         unsafe {
72             bindings::sysbus_init_irq(self.upcast().as_mut_ptr(), irq.as_ptr());
73         }
74     }
75 
76     // TODO: do we want a type like GuestAddress here?
77     fn mmio_addr(&self, id: u32) -> Option<u64> {
78         assert!(bql::is_locked());
79         // SAFETY: the BQL ensures that no one else writes to sbd.mmio[], and
80         // the SysBusDevice must be initialized to get an IsA<SysBusDevice>.
81         let sbd = unsafe { *self.upcast().as_ptr() };
82         let id: usize = id.try_into().unwrap();
83         if sbd.mmio[id].memory.is_null() {
84             None
85         } else {
86             Some(sbd.mmio[id].addr)
87         }
88     }
89 
90     // TODO: do we want a type like GuestAddress here?
91     fn mmio_map(&self, id: u32, addr: u64) {
92         assert!(bql::is_locked());
93         let id: i32 = id.try_into().unwrap();
94         unsafe {
95             bindings::sysbus_mmio_map(self.upcast().as_mut_ptr(), id, addr);
96         }
97     }
98 
99     // Owned<> is used here because sysbus_connect_irq (via
100     // object_property_set_link) adds a reference to the IRQState,
101     // which can prolong its life
102     fn connect_irq(&self, id: u32, irq: &Owned<IRQState>) {
103         assert!(bql::is_locked());
104         let id: i32 = id.try_into().unwrap();
105         let irq: &IRQState = irq;
106         unsafe {
107             bindings::sysbus_connect_irq(self.upcast().as_mut_ptr(), id, irq.as_mut_ptr());
108         }
109     }
110 
111     fn sysbus_realize(&self) -> Result<()> {
112         assert!(bql::is_locked());
113         unsafe {
114             Error::with_errp(|errp| {
115                 bindings::sysbus_realize(self.upcast().as_mut_ptr(), errp);
116             })
117         }
118     }
119 }
120 
121 impl<R: ObjectDeref> SysBusDeviceMethods for R where R::Target: IsA<SysBusDevice> {}
122