kern: implement SvcCreateInterruptEvent

libraries/libmesosphere/source/kern_k_interrupt_event.cpp

@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <mesosphere.hpp>
+
+namespace ams::kern {
+
+    namespace {
+
+        constinit KLightLock g_interrupt_event_lock;
+        constinit KInterruptEventTask *g_interrupt_event_task_table[KInterruptController::NumInterrupts] = {};
+
+    }
+
+    Result KInterruptEvent::Initialize(int32_t interrupt_name, ams::svc::InterruptType type) {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Set interrupt id. */
+        this->interrupt_id = interrupt_name;
+
+        /* Initialize readable event base. */
+        KReadableEvent::Initialize(nullptr);
+
+        /* Try to register the task. */
+        R_TRY(KInterruptEventTask::Register(std::addressof(this->task), this->interrupt_id, type == ams::svc::InterruptType_Level, this));
+
+        /* Mark initialized. */
+        this->is_initialized = true;
+        return ResultSuccess();
+    }
+
+    void KInterruptEvent::Finalize() {
+        MESOSPHERE_ASSERT_THIS();
+
+        MESOSPHERE_ASSERT(this->task != nullptr);
+        this->task->Unregister();
+    }
+
+    Result KInterruptEvent::Reset() {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Lock the task table. */
+        KScopedLightLock lk(g_interrupt_event_lock);
+
+        /* Clear the event. */
+        R_TRY(KReadableEvent::Reset());
+
+        /* Clear the interrupt. */
+        Kernel::GetInterruptManager().ClearInterrupt(this->interrupt_id);
+
+        return ResultSuccess();
+    }
+
+    Result KInterruptEventTask::Register(KInterruptEventTask **out, s32 interrupt_id, bool level, KInterruptEvent *event) {
+        /* Verify the interrupt id is defined and global. */
+        R_UNLESS(Kernel::GetInterruptManager().IsInterruptDefined(interrupt_id), svc::ResultOutOfRange());
+        R_UNLESS(Kernel::GetInterruptManager().IsGlobal(interrupt_id),           svc::ResultOutOfRange());
+
+        /* Lock the task table. */
+        KScopedLightLock lk(g_interrupt_event_lock);
+
+        /* Get a task for the id. */
+        bool allocated = false;
+        KInterruptEventTask *task = g_interrupt_event_task_table[interrupt_id];
+        if (task != nullptr) {
+            /* Check that there's not already an event for this task. */
+            R_UNLESS(task->event == nullptr, svc::ResultBusy());
+        } else {
+            /* Allocate a new task. */
+            task = KInterruptEventTask::Allocate();
+            R_UNLESS(task != nullptr, svc::ResultOutOfResource());
+
+            allocated = true;
+        }
+
+        /* Register/bind the interrupt task. */
+        {
+            /* Ensure that the task is cleaned up if anything goes wrong. */
+            auto task_guard = SCOPE_GUARD { if (allocated) { KInterruptEventTask::Free(task); } };
+
+            /* Bind the interrupt handler. */
+            R_TRY(Kernel::GetInterruptManager().BindHandler(task, interrupt_id, GetCurrentCoreId(), KInterruptController::PriorityLevel_High, true, level));
+
+            /* We successfully registered, so we don't need to free the task. */
+            task_guard.Cancel();
+        }
+
+        /* Set the event. */
+        task->event = event;
+
+        /* If we allocated, set the event in the table. */
+        if (allocated) {
+            task->interrupt_id = interrupt_id;
+            g_interrupt_event_task_table[interrupt_id] = task;
+        }
+
+        /* Set the output. */
+        *out = task;
+        return ResultSuccess();
+    }
+
+    void KInterruptEventTask::Unregister() {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Lock the task table. */
+        KScopedLightLock lk(g_interrupt_event_lock);
+
+        /* Ensure we can unregister. */
+        MESOSPHERE_ABORT_UNLESS(g_interrupt_event_task_table[this->interrupt_id] == this);
+        MESOSPHERE_ABORT_UNLESS(this->event != nullptr);
+        this->event = nullptr;
+
+        /* Unbind the interrupt. */
+        Kernel::GetInterruptManager().UnbindHandler(this->interrupt_id, GetCurrentCoreId());
+    }
+
+    KInterruptTask *KInterruptEventTask::OnInterrupt(s32 interrupt_id) {
+        MESOSPHERE_ASSERT_THIS();
+
+        return this;
+    }
+
+    void KInterruptEventTask::DoTask() {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Lock the task table. */
+        KScopedLightLock lk(g_interrupt_event_lock);
+
+        if (this->event != nullptr) {
+            this->event->Signal();
+        }
+    }
+}