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) { fn post_init(&self) {
let sbd: &SysBusDevice = self.upcast(); self.init_mmio(&self.iomem);
sbd.init_mmio(&self.iomem);
for irq in self.interrupts.iter() { 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 /// 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 /// type [`IRQState`]. A device exposes its source as a QOM link property using
/// a function such as /// a function such as [`SysBusDeviceMethods::init_irq`], and
/// [`SysBusDevice::init_irq`](crate::sysbus::SysBusDevice::init_irq), and
/// initially leaves the pointer to a NULL value, representing an unconnected /// initially leaves the pointer to a NULL value, representing an unconnected
/// interrupt. To connect it, whoever creates the device fills the pointer with /// interrupt. To connect it, whoever creates the device fills the pointer with
/// the sink's `IRQState *`, for example using `sysbus_connect_irq`. Because /// 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::ObjectType;
pub use crate::qom_isa; pub use crate::qom_isa;
pub use crate::sysbus::SysBusDeviceMethods;

View file

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