zx/
iommu.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 iommu objects.
6
7use crate::{ok, sys, AsHandleRef, Handle, HandleBased, HandleRef, Resource, Status};
8
9/// An object representing a Zircon iommu
10///
11/// As essentially a subtype of `Handle`, it can be freely interconverted.
12#[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
13#[repr(transparent)]
14pub struct Iommu(Handle);
15impl_handle_based!(Iommu);
16
17// ABI-compatible with zx_iommu_desc_dummy_t.
18#[repr(C)]
19#[derive(Debug, Copy, Clone, Default, Eq, PartialEq)]
20pub struct IommuDescDummy {
21    padding1: u8,
22}
23
24impl Iommu {
25    // Create an iommu object.
26    //
27    // Wraps the
28    // [`zx_iommu_create`](https://fuchsia.dev/fuchsia-src/reference/syscalls/iommu_create) system call to create an iommu with type `ZX_IOMMU_TYPE_DUMMY`
29    pub fn create_dummy(resource: &Resource, desc: IommuDescDummy) -> Result<Iommu, Status> {
30        let mut iommu_handle = sys::zx_handle_t::default();
31        let status = unsafe {
32            // SAFETY:
33            //  * desc parameter is a valid pointer (desc).
34            //  * desc_size parameter is the size of desc.
35            sys::zx_iommu_create(
36                resource.raw_handle(),
37                sys::ZX_IOMMU_TYPE_DUMMY,
38                std::ptr::from_ref(&desc).cast::<u8>(),
39                std::mem::size_of_val(&desc),
40                &mut iommu_handle,
41            )
42        };
43        ok(status)?;
44        unsafe {
45            // SAFETY: The syscall docs claim that upon success, iommu_handle will be a valid
46            // handle to an iommu object.
47            Ok(Iommu::from(Handle::from_raw(iommu_handle)))
48        }
49    }
50}
51
52#[cfg(test)]
53mod tests {
54    use super::*;
55    use crate::ObjectType;
56    use fidl_fuchsia_kernel as fkernel;
57    use fuchsia_component::client::connect_channel_to_protocol;
58
59    #[test]
60    fn iommu_create_invalid_resource() {
61        let status =
62            Iommu::create_dummy(&Resource::from(Handle::invalid()), IommuDescDummy::default());
63        assert_eq!(status, Err(Status::BAD_HANDLE));
64    }
65
66    #[test]
67    fn iommu_create_valid() {
68        use zx::{Channel, HandleBased, MonotonicInstant};
69        let (client_end, server_end) = Channel::create();
70        connect_channel_to_protocol::<fkernel::IommuResourceMarker>(server_end).unwrap();
71        let service = fkernel::IommuResourceSynchronousProxy::new(client_end);
72        let resource =
73            service.get(MonotonicInstant::INFINITE).expect("couldn't get iommu resource");
74        // This test and fuchsia-zircon are different crates, so we need
75        // to use from_raw to convert between the zx handle and this test handle.
76        // See https://fxbug.dev/42173139 for details.
77        let resource = unsafe { Resource::from(Handle::from_raw(resource.into_raw())) };
78        let iommu = Iommu::create_dummy(&resource, IommuDescDummy::default()).unwrap();
79        assert!(!iommu.as_handle_ref().is_invalid());
80
81        let info = iommu.as_handle_ref().basic_info().unwrap();
82        assert_eq!(info.object_type, ObjectType::IOMMU);
83    }
84}
zx/iommu.rs

zx/
iommu.rs
