feat: kernel/drivers/irq: switch to atomic ptr

kernel/src/drivers/irq/plic.rs

@@ -2,6 +2,7 @@ use super::IrqDriver;
 use crate::drivers::Driver;
 use crate::entry::HART_ID;
 use crate::plat::irq::IrqController;
+use core::sync::atomic::{AtomicPtr, Ordering};
 use fdt::{node::FdtNode, Fdt};
 use log::trace;
 
@@ -27,17 +28,35 @@ struct PlicCtrl {
 pub struct IrqPlic
 where IrqPlic: IrqDriver
 {
-    priority: *mut u32,
+    priority: AtomicPtr<u32>,
-    pending:  *mut u32,
+    pending:  AtomicPtr<u32>,
-    enable:   *mut u32,
+    enable:   AtomicPtr<u32>,
-    control:  *mut PlicCtrl,
+    control:  AtomicPtr<PlicCtrl>,
 
     nr_irqs: usize,
 }
 
+impl IrqPlic {
+    fn priority(&self) -> *mut u32 {
+        self.priority.load(Ordering::Relaxed)
+    }
+
+    fn pending(&self) -> *mut u32 {
+        self.pending.load(Ordering::Relaxed)
+    }
+
+    fn enable(&self) -> *mut u32 {
+        self.enable.load(Ordering::Relaxed)
+    }
+
+    fn control(&self) -> *mut PlicCtrl {
+        self.control.load(Ordering::Relaxed)
+    }
+}
+
 impl Driver for IrqPlic {
     fn compatible() -> &'static [&'static str] {
-        &["riscv,plic0"]
+        &["sifive,plic-1.0.0", "riscv,plic0"]
     }
 
     fn setup(node: FdtNode, fdt: &Fdt) -> Self {
@@ -88,11 +107,16 @@ impl Driver for IrqPlic {
 
         let ctx_id = ctx_id.expect("No PLIC context found for us");
 
+        let priority = unsafe { base_address.add(PLIC_PRIORITY_OFFSET) as *mut u32 };
+        let pending = unsafe { base_address.add(PLIC_PENDING_OFFSET) as *mut u32 };
+        let enable = unsafe { base_address.add(PLIC_ENABLE_OFFSET + ctx_id * PLIC_ENABLE_STRIDE) as *mut u32 };
+        let control = unsafe { (base_address.add(PLIC_CONTROL_OFFSET) as *mut PlicCtrl).add(ctx_id) };
+
         Self {
-            priority: unsafe { base_address.add(PLIC_PRIORITY_OFFSET) as *mut u32 },
+            priority: AtomicPtr::new(priority),
-            pending:  unsafe { base_address.add(PLIC_PENDING_OFFSET) as *mut u32 },
+            pending:  AtomicPtr::new(pending),
-            enable:   unsafe { base_address.add(PLIC_ENABLE_OFFSET + ctx_id * PLIC_ENABLE_STRIDE) as *mut u32 },
+            enable:   AtomicPtr::new(enable),
-            control:  unsafe { (base_address.add(PLIC_CONTROL_OFFSET) as *mut PlicCtrl).add(ctx_id) },
+            control:  AtomicPtr::new(control),
             nr_irqs:  nr_irqs.unwrap(),
         }
     }
@@ -107,9 +131,9 @@ impl IrqController for IrqPlic {
         let word = irq / 32;
         let bit = irq % 32;
 
-        let val = unsafe { self.enable.add(word).read_volatile() };
+        let val = unsafe { IrqPlic::enable(self).add(word).read_volatile() };
         let val = val | (1 << bit);
-        unsafe { self.enable.add(word).write_volatile(val) };
+        unsafe { IrqPlic::enable(self).add(word).write_volatile(val) };
     }
 
     fn disable(&mut self, irq: usize) {
@@ -120,9 +144,9 @@ impl IrqController for IrqPlic {
         let word = irq / 32;
         let bit = irq % 32;
 
-        let val = unsafe { self.enable.add(word).read_volatile() };
+        let val = unsafe { IrqPlic::enable(self).add(word).read_volatile() };
         let val = val & !(1 << bit);
-        unsafe { self.enable.add(word).write_volatile(val) };
+        unsafe { IrqPlic::enable(self).add(word).write_volatile(val) };
     }
 
     fn is_pending(&mut self, irq: usize) -> bool {
@@ -133,12 +157,12 @@ impl IrqController for IrqPlic {
         let word = irq / 32;
         let bit = irq % 32;
 
-        let val = unsafe { self.pending.add(word).read_volatile() };
+        let val = unsafe { IrqPlic::pending(self).add(word).read_volatile() };
         val & (1 << bit) != 0
     }
 
     fn claim(&mut self) -> Option<usize> {
-        let val = unsafe { self.control.as_ref().unwrap().claim.read_volatile() };
+        let val = unsafe { IrqPlic::control(self).as_ref().unwrap().claim.read_volatile() };
 
         if val > 0 {
             Some(val as usize)
@@ -153,7 +177,7 @@ impl IrqController for IrqPlic {
         }
 
         let val = irq as u32;
-        unsafe { self.control.as_ref().unwrap().claim.write_volatile(val) };
+        unsafe { IrqPlic::control(self).as_ref().unwrap().claim.write_volatile(val) };
     }
 }
 

kernel/src/plat/irq.rs

@@ -1,6 +1,7 @@
 use super::utils::generate_driver;
 use crate::drivers::irq::IrqPlic;
 use crate::objects::*;
+use spin::{lazy::Lazy, Mutex};
 
 const IRQ_NUM: usize = 32;
 
@@ -15,7 +16,7 @@ pub enum IrqState {
 generate_driver!(
     IrqDriver {
         (IrqPlic),
-        ()
+        (DummyIrqDriver)
     } : IrqController {
         fn enable(&mut self, irq: usize) -> ();
         fn disable(&mut self, irq: usize) -> ();
@@ -25,11 +26,33 @@ generate_driver!(
     }
 );
 
+pub struct DummyIrqDriver;
+
+impl IrqController for DummyIrqDriver {
+    fn enable(&mut self, _: usize) {}
+    fn disable(&mut self, _: usize) {}
+    fn is_pending(&mut self, _: usize) -> bool {
+        false
+    }
+    fn claim(&mut self) -> Option<usize> {
+        None
+    }
+    fn complete(&mut self, _: usize) {}
+}
+
+static IRQ_DRIVER: Mutex<IrqDriver> = Mutex::new(IrqDriver::DummyIrqDriver(DummyIrqDriver));
+
+pub fn set_irq_driver(driver: IrqDriver) {
+    *IRQ_DRIVER.lock() = driver;
+}
+
 pub struct IrqManager {
     handler: [CapEntry; IRQ_NUM],
     state:   [IrqState; IRQ_NUM],
 }
 
+pub static IRQ_MANAGER: Mutex<Lazy<IrqManager>> = Mutex::new(Lazy::new(IrqManager::new));
+
 impl IrqManager {
     pub fn new() -> Self {
         Self {