task.h required for building

2 files changed, 109 insertions, 0 deletions

diff --git a/kc/core/task.c b/kc/core/task.c
new file mode 100644
index 0000000..8f78516
--- /dev/null
+++ b/kc/core/task.c
@@ -0,0 +1,76 @@
+#include "task.h"
+#include "memory.h"
+#include "panic.h"
+#include "cpu.h"
+
+struct kc_thread *current_task = NULL;
+struct kc_thread *first_ready_task = NULL;
+struct kc_thread *last_ready_task = NULL;
+
+static int schedule_lock_cnt = 0;
+
+static void lock_scheduler(void);
+static void unlock_scheduler(void);
+static void set_thread_status(enum kc_thread_status status);
+static void idle_task_thread(void);
+
+extern uint64_t *get_tss_rsp0(void);
+
+void task_set_thread(struct kc_thread *task)
+{
+    // wrapper around cpu_set_thread
+    uint64_t *rsp0 = get_tss_rsp0();
+    cpu_set_thread(&current_task->state, &task->state, rsp0);
+}
+
+void task_schedule(void)
+{
+    if (first_ready_task)
+    {
+        struct kc_thread *task = first_ready_task;
+        first_ready_task = task->next;
+        task_set_thread(task);
+    }
+}
+
+static void lock_scheduler(void)
+{
+    __asm__ volatile ("cli;");
+    schedule_lock_cnt++;
+}
+
+static void unlock_scheduler(void)
+{
+    if (1 == schedule_lock_cnt)
+    {
+        schedule_lock_cnt--;
+        __asm__ volatile("sti;");
+    }
+}
+
+static void unblock_thread(struct kc_thread *thread)
+{
+    lock_scheduler();
+    if (!first_ready_task)
+    {
+        task_set_thread(thread);
+    }
+    else
+    {
+        first_ready_task->next = thread;
+        first_ready_task = thread;
+    }
+}
+
+static void set_thread_status(enum kc_thread_status status)
+{
+    lock_scheduler();
+    current_task->status = status;
+    task_schedule();
+    unlock_scheduler();
+}
+
+static void idle_task_thread(void)
+{
+}
+
diff --git a/kc/core/task.h b/kc/core/task.h
new file mode 100644
index 0000000..86e262f
--- /dev/null
+++ b/kc/core/task.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#include <stdint.h>
+
+enum kc_thread_status
+{
+    READY,
+    STARTED,
+    YIELDED,
+    BLOCKED,
+    TERMINATED
+};
+
+struct kc_thread_state
+{
+    uint64_t stack;
+    uint64_t stack_top;
+    uint64_t page_map;
+};
+
+struct kc_thread
+{
+    struct kc_thread *prev;
+    struct kc_thread *next;
+    enum kc_thread_status status;
+    struct kc_thread_state state;
+};
+
+extern void cpu_set_thread(
+        struct kc_thread_state *current,
+        struct kc_thread_state *next,
+        uint64_t *cpu_tss_rsp0);
+