zx/
bti.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! Type-safe bindings for Zircon bti objects.
6
7use crate::{ok, AsHandleRef, Handle, HandleBased, HandleRef, Iommu, Status};
8
9/// An object representing a Zircon Bus Transaction Initiator object.
10/// See [BTI Documentation](https://fuchsia.dev/fuchsia-src/reference/kernel_objects/bus_transaction_initiator) for details.
11///
12/// As essentially a subtype of `Handle`, it can be freely interconverted.
13#[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
14#[repr(transparent)]
15pub struct Bti(Handle);
16impl_handle_based!(Bti);
17
18impl Bti {
19    // Create a Bus Transaction Initiator object.
20    // Wraps the
21    // [`zx_bti_create`](https://fuchsia.dev/fuchsia-src/reference/syscalls/bti_create) system call to create a bti.
22    pub fn create(iommu: &Iommu, id: u64) -> Result<Bti, Status> {
23        let mut bti_handle = crate::sys::zx_handle_t::default();
24        let status = unsafe {
25            // SAFETY: regular system call with no unsafe parameters.
26            crate::sys::zx_bti_create(iommu.raw_handle(), 0, id, &mut bti_handle)
27        };
28        ok(status)?;
29        unsafe {
30            // SAFETY: The syscall docs claim that upon success, bti_handle will be a valid
31            // handle to bti object.
32            Ok(Bti::from(Handle::from_raw(bti_handle)))
33        }
34    }
35}
36
37#[cfg(test)]
38mod tests {
39    use super::*;
40    use crate::{IommuDescDummy, ObjectType, Resource, Vmo};
41    use fidl_fuchsia_kernel as fkernel;
42    use fuchsia_component::client::connect_channel_to_protocol;
43
44    #[test]
45    fn create_bti_invalid_handle() {
46        let status = Bti::create(&Iommu::from(Handle::invalid()), 0);
47        assert_eq!(status, Err(Status::BAD_HANDLE));
48    }
49
50    #[test]
51    fn create_bti_wrong_handle() {
52        let vmo = Vmo::create(0).unwrap();
53        let wrong_handle = unsafe { Iommu::from(Handle::from_raw(vmo.into_raw())) };
54
55        let status = Bti::create(&wrong_handle, 0);
56        assert_eq!(status, Err(Status::WRONG_TYPE));
57    }
58
59    fn create_iommu() -> Iommu {
60        use zx::{Channel, HandleBased, MonotonicInstant};
61        let (client_end, server_end) = Channel::create();
62        connect_channel_to_protocol::<fkernel::IommuResourceMarker>(server_end).unwrap();
63        let service = fkernel::IommuResourceSynchronousProxy::new(client_end);
64        let resource =
65            service.get(MonotonicInstant::INFINITE).expect("couldn't get iommu resource");
66        // This test and fuchsia-zircon are different crates, so we need
67        // to use from_raw to convert between the zx handle and this test handle.
68        // See https://fxbug.dev/42173139 for details.
69        let resource = unsafe { Resource::from(Handle::from_raw(resource.into_raw())) };
70        Iommu::create_dummy(&resource, IommuDescDummy::default()).unwrap()
71    }
72
73    #[test]
74    fn create_from_valid_iommu() {
75        let iommu = create_iommu();
76        let bti = Bti::create(&iommu, 0).unwrap();
77
78        let info = bti.as_handle_ref().basic_info().unwrap();
79        assert_eq!(info.object_type, ObjectType::BTI);
80    }
81}
zx/bti.rs

zx/
bti.rs
