@@ -13,8 +13,8 @@
c_str, impl_vmstate_forward,
irq::InterruptSource,
prelude::*,
- qdev::DeviceImpl,
- qom::{ClassInitImpl, ObjectImpl, ParentField},
+ qdev::{Clock, ClockEvent, DeviceImpl},
+ qom::{ClassInitImpl, ObjectImpl, Owned, ParentField},
};
use crate::{
@@ -123,7 +123,7 @@ pub struct PL011State {
#[doc(alias = "irq")]
pub interrupts: [InterruptSource; IRQMASK.len()],
#[doc(alias = "clk")]
- pub clock: NonNull<Clock>,
+ pub clock: Owned<Clock>,
#[doc(alias = "migrate_clk")]
pub migrate_clock: bool,
}
@@ -487,8 +487,6 @@ impl PL011State {
/// location/instance. All its fields are expected to hold unitialized
/// values with the sole exception of `parent_obj`.
unsafe fn init(&mut self) {
- const CLK_NAME: &CStr = c_str!("clk");
-
// SAFETY:
//
// self and self.iomem are guaranteed to be valid at this point since callers
@@ -508,22 +506,16 @@ unsafe fn init(&mut self) {
// SAFETY:
//
- // self.clock is not initialized at this point; but since `NonNull<_>` is Copy,
- // we can overwrite the undefined value without side effects. This is
+ // self.clock is not initialized at this point; but since `NonNull<_>` is
+ // not Drop, we can overwrite the undefined value without side effects. This is
// safe since all PL011State instances are created by QOM code which
// calls this function to initialize the fields; therefore no code is
// able to access an invalid self.clock value.
- unsafe {
- let dev: &mut DeviceState = self.upcast_mut();
- self.clock = NonNull::new(qdev_init_clock_in(
- dev,
- CLK_NAME.as_ptr(),
- None, /* pl011_clock_update */
- addr_of_mut!(*self).cast::<c_void>(),
- ClockEvent::ClockUpdate.0,
- ))
- .unwrap();
- }
+ self.clock = self.init_clock_in("clk", &Self::clock_update, ClockEvent::ClockUpdate);
+ }
+
+ const fn clock_update(&self, _event: ClockEvent) {
+ /* pl011_trace_baudrate_change(s); */
}
fn post_init(&self) {
@@ -7,6 +7,8 @@
pub use crate::cell::BqlCell;
pub use crate::cell::BqlRefCell;
+pub use crate::qdev::DeviceMethods;
+
pub use crate::qom::IsA;
pub use crate::qom::Object;
pub use crate::qom::ObjectCast;
@@ -4,14 +4,19 @@
//! Bindings to create devices and access device functionality from Rust.
-use std::ffi::CStr;
+use std::{
+ ffi::{CStr, CString},
+ os::raw::c_void,
+};
-pub use bindings::{DeviceClass, DeviceState, Property};
+pub use bindings::{Clock, ClockEvent, DeviceClass, DeviceState, Property};
use crate::{
bindings::{self, Error},
+ callbacks::FnCall,
+ cell::bql_locked,
prelude::*,
- qom::{ClassInitImpl, ObjectClass},
+ qom::{ClassInitImpl, ObjectClass, Owned},
vmstate::VMStateDescription,
};
@@ -145,3 +150,68 @@ unsafe impl ObjectType for DeviceState {
unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_DEVICE) };
}
qom_isa!(DeviceState: Object);
+
+pub trait DeviceMethods: ObjectDeref
+where
+ Self::Target: IsA<DeviceState>,
+{
+ #[inline]
+ fn init_clock_in<F: for<'a> FnCall<(&'a Self::Target, ClockEvent)>>(
+ &self,
+ name: &str,
+ _cb: &F,
+ events: ClockEvent,
+ ) -> Owned<Clock> {
+ fn do_init_clock_in(
+ dev: *mut DeviceState,
+ name: &str,
+ cb: Option<unsafe extern "C" fn(*mut c_void, ClockEvent)>,
+ events: ClockEvent,
+ ) -> Owned<Clock> {
+ assert!(bql_locked());
+
+ // SAFETY: the clock is heap allocated and does not have a reference, so
+ // Owned::from adds one. the callback is disabled automatically
+ // when the clock is unparented, which happens before the device is
+ // finalized.
+ unsafe {
+ let cstr = CString::new(name).unwrap();
+ let clk = bindings::qdev_init_clock_in(
+ dev,
+ cstr.as_ptr(),
+ cb,
+ dev.cast::<c_void>(),
+ events.0,
+ );
+
+ Owned::from(&*clk)
+ }
+ }
+
+ let cb: Option<unsafe extern "C" fn(*mut c_void, ClockEvent)> = if F::is_some() {
+ unsafe extern "C" fn rust_clock_cb<T, F: for<'a> FnCall<(&'a T, ClockEvent)>>(
+ opaque: *mut c_void,
+ event: ClockEvent,
+ ) {
+ // SAFETY: the opaque is "this", which is indeed a pointer to T
+ F::call((unsafe { &*(opaque.cast::<T>()) }, event))
+ }
+ Some(rust_clock_cb::<Self::Target, F>)
+ } else {
+ None
+ };
+
+ // SAFETY: self can be cast to DeviceState because its type has an
+ // IsA<DeviceState> bound.
+ do_init_clock_in(unsafe { self.as_mut_ptr() }, name, cb, events)
+ }
+}
+
+impl<R: ObjectDeref> DeviceMethods for R where R::Target: IsA<DeviceState> {}
+
+unsafe impl ObjectType for Clock {
+ type Class = ObjectClass;
+ const TYPE_NAME: &'static CStr =
+ unsafe { CStr::from_bytes_with_nul_unchecked(bindings::TYPE_CLOCK) };
+}
+qom_isa!(Clock: Object);
@@ -470,11 +470,11 @@ macro_rules! vmstate_clock {
$crate::assert_field_type!(
$struct_name,
$field_name,
- core::ptr::NonNull<$crate::bindings::Clock>
+ $crate::qom::Owned<$crate::bindings::Clock>
);
$crate::offset_of!($struct_name, $field_name)
},
- size: ::core::mem::size_of::<*const $crate::bindings::Clock>(),
+ size: ::core::mem::size_of::<*const $crate::qdev::Clock>(),
flags: VMStateFlags(VMStateFlags::VMS_STRUCT.0 | VMStateFlags::VMS_POINTER.0),
vmsd: unsafe { ::core::ptr::addr_of!($crate::bindings::vmstate_clock) },
..$crate::zeroable::Zeroable::ZERO
Add a Rust version of qdev_init_clock_in, which can be used in instance_init. There are a couple differences with the C version: - in Rust the object keeps its own reference to the clock (in addition to the one embedded in the NamedClockList), and the reference is dropped automatically by instance_finalize(); this is encoded in the signature of DeviceClassMethods::init_clock_in, which makes the lifetime of the clock independent of that of the object it holds. This goes unnoticed in the C version and is due to the existence of aliases. - also, anything that happens during instance_init uses the pinned_init framework to operate on a partially initialized object, and is done through class methods (i.e. through DeviceClassMethods rather than DeviceMethods) because the device does not exist yet. Therefore, Rust code *must* create clocks from instance_init, which is stricter than C. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- rust/hw/char/pl011/src/device.rs | 28 +++++------- rust/qemu-api/src/prelude.rs | 2 + rust/qemu-api/src/qdev.rs | 76 ++++++++++++++++++++++++++++++-- rust/qemu-api/src/vmstate.rs | 4 +- 4 files changed, 87 insertions(+), 23 deletions(-)