rust: qdev: expose inherited methods to subclasses of SysBusDevice

The ObjectDeref trait now provides all the magic that is required to fake
inheritance.  Replace the "impl SysBusDevice" block of qemu_api::sysbus
with a trait, so that sysbus_init_irq() can be invoked as "self.init_irq()"
without any intermediate upcast.

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2024-11-29 10:46:44 +01:00
parent 809c703a60
commit 559a779c6a
4 changed files with 14 additions and 14 deletions

View file

@ -207,11 +207,9 @@ impl PL011State {
}
fn post_init(&self) {
let sbd: &SysBusDevice = self.upcast();
sbd.init_mmio(&self.iomem);
self.init_mmio(&self.iomem);
for irq in self.interrupts.iter() {
sbd.init_irq(irq);
self.init_irq(irq);
}
}

View file

@ -24,8 +24,7 @@ use crate::{
///
/// Interrupts are implemented as a pointer to the interrupt "sink", which has
/// type [`IRQState`]. A device exposes its source as a QOM link property using
/// a function such as
/// [`SysBusDevice::init_irq`](crate::sysbus::SysBusDevice::init_irq), and
/// a function such as [`SysBusDeviceMethods::init_irq`], and
/// initially leaves the pointer to a NULL value, representing an unconnected
/// interrupt. To connect it, whoever creates the device fills the pointer with
/// the sink's `IRQState *`, for example using `sysbus_connect_irq`. Because

View file

@ -16,3 +16,5 @@ pub use crate::qom::ObjectMethods;
pub use crate::qom::ObjectType;
pub use crate::qom_isa;
pub use crate::sysbus::SysBusDeviceMethods;

View file

@ -32,18 +32,17 @@ where
}
}
impl SysBusDevice {
/// Return `self` cast to a mutable pointer, for use in calls to C code.
const fn as_mut_ptr(&self) -> *mut SysBusDevice {
addr_of!(*self) as *mut _
}
/// Trait for methods of [`SysBusDevice`] and its subclasses.
pub trait SysBusDeviceMethods: ObjectDeref
where
Self::Target: IsA<SysBusDevice>,
{
/// Expose a memory region to the board so that it can give it an address
/// in guest memory. Note that the ordering of calls to `init_mmio` is
/// important, since whoever creates the sysbus device will refer to the
/// region with a number that corresponds to the order of calls to
/// `init_mmio`.
pub fn init_mmio(&self, iomem: &bindings::MemoryRegion) {
fn init_mmio(&self, iomem: &bindings::MemoryRegion) {
assert!(bql_locked());
unsafe {
bindings::sysbus_init_mmio(self.as_mut_ptr(), addr_of!(*iomem) as *mut _);
@ -54,10 +53,12 @@ impl SysBusDevice {
/// Note that the ordering of calls to `init_irq` is important, since
/// whoever creates the sysbus device will refer to the interrupts with
/// a number that corresponds to the order of calls to `init_irq`.
pub fn init_irq(&self, irq: &InterruptSource) {
fn init_irq(&self, irq: &InterruptSource) {
assert!(bql_locked());
unsafe {
bindings::sysbus_init_irq(self.as_mut_ptr(), irq.as_ptr());
}
}
}
impl<R: ObjectDeref> SysBusDeviceMethods for R where R::Target: IsA<SysBusDevice> {}