acpi-rs: add connect_op_regions() + repair initialize_namespace

Add public connect_op_regions() (ACPICA evrgnini.c): \_SB._REG(space, 1)
per installed handler space plus <device>._REG(space, 1) per device holding
an OpRegion of that space. initialize_namespace() now delegates to it and
its ACPICA-order opening (_INI, _SB._INI) is restored after 0c11c2b5
captured a broken intermediate edit. Completes the _REG wiring begun in
c3a27717 (which delivered the acpid-side call).

drivers/acpi-rs/src/aml/mod.rs

@@ -241,10 +241,79 @@ where
         handlers.insert(space, handler);
     }
 
+    /// `_REG` opregion connect (ACPICA evrgnini.c): `\_SB._REG(space, 1)` per
+    /// installed handler + `<device>._REG(space, 1)` per device holding an
+    /// OpRegion of that space. Firmware gates EC access behind this. Idempotent.
+    pub fn connect_op_regions(&self) {
+        let installed_spaces: Vec<RegionSpace> =
+            self.region_handlers.lock().keys().copied().collect();
+
+        for space in &installed_spaces {
+            let space_id = u8::from(*space) as u64;
+            if let Err(err) = self.evaluate_if_present(
+                AmlName::from_str("\\_SB._REG").unwrap(),
+                vec![Object::Integer(space_id).wrap(), Object::Integer(1).wrap()],
+            ) {
+                warn!("\\_SB._REG({:?}, connect) failed: {:?}", space, err);
+            }
+        }
+
+        let mut reg_namespace = self.namespace.lock().clone();
+        let _ = reg_namespace.traverse(|path, level| {
+            match level.kind {
+                NamespaceLevelKind::Device
+                | NamespaceLevelKind::Processor
+                | NamespaceLevelKind::ThermalZone
+                | NamespaceLevelKind::PowerResource => {
+                    let mut device_spaces: Vec<RegionSpace> = level
+                        .values
+                        .values()
+                        .filter_map(|(_, obj)| match &**obj {
+                            Object::OpRegion(region)
+                                if installed_spaces.contains(&region.space) =>
+                            {
+                                Some(region.space)
+                            }
+                            _ => None,
+                        })
+                        .collect();
+                    device_spaces.sort();
+                    device_spaces.dedup();
+                    for space in device_spaces {
+                        let space_id = u8::from(space) as u64;
+                        if let Ok(reg_path) =
+                            AmlName::from_str("_REG").unwrap().resolve(path)
+                        {
+                            let _ = self.evaluate_if_present(
+                                reg_path,
+                                vec![Object::Integer(space_id).wrap(), Object::Integer(1).wrap()],
+                            );
+                        }
+                    }
+                    Ok(true)
+                }
+                _ => Ok(true),
+            }
+        });
+    }
+
     /// Initialize the namespace - this should be called after all tables have been loaded and
     /// operation region handlers registered. Specifically, it will call relevant `_STA`, `_INI`,
     /// and `_REG` methods.
     pub fn initialize_namespace(&self) {
+        /*
+         * This should match the initialization order of ACPICA and uACPI.
+         */
+        if let Err(err) = self.evaluate_if_present(AmlName::from_str("\\_INI").unwrap(), vec![]) {
+            warn!("Invoking \\_INI failed: {:?}", err);
+        }
+        if let Err(err) = self.evaluate_if_present(AmlName::from_str("\\_SB._INI").unwrap(), vec![]) {
+            warn!("Invoking \\_SB._INI failed: {:?}", err);
+        }
+
+        self.connect_op_regions();
+
+        /*
          * We can now initialize each device in the namespace. For each device, we evaluate `_STA`,
          * which indicates if the device is present and functional. If this method does not exist,
          * we assume the device should be initialized.