1 files changed, 245 insertions, 0 deletions
diff --git a/src/kernel/task/task.c b/src/kernel/task/task.c
new file mode 100644
index 0000000..804adc2
--- /dev/null
+++ b/src/kernel/task/task.c
@@ -0,0 +1,245 @@
+#include "task.h"
+#include <core/sys.h>
+#include <core/monitor.h>
+#include <mem/mem.h>
+#include "timer.h"
+
+#define KSTACKSIZE 0x8000
+
+//Static routines for handling threads exiting and all cleanup
+static void thread_exit_stackJmp(uint32_t reason);
+static void thread_exit2(uint32_t reason);
+static void thread_delete(struct thread *th);
+static void process_delete(struct process *pr);
+
+//From task_.asm
+extern uint32_t read_eip();
+extern void task_idle(void*);
+
+static uint32_t thread_runnable(struct thread *th);
+
+static uint32_t nextpid = 1;
+
+struct process *processes = 0, *kernel_process;
+struct thread *threads = 0, *current_thread = 0, *idle_thread;
+
+uint32_t tasking_tmpStack[0x4000];
+
+void tasking_init() {
+	cli();
+	kernel_process = kmalloc(sizeof(struct process));	//This process must be hidden to users
+	kernel_process->pid = kernel_process->uid = kernel_process->threads = 0;
+	kernel_process->privilege = PL_KERNEL;
+	kernel_process->parent = kernel_process;
+	kernel_process->pagedir = kernel_pagedir;
+	kernel_process->next = 0;
+	current_thread = 0;
+	idle_thread = thread_new(kernel_process, task_idle, 0);
+	threads = 0;	//Do not include idle thread in threads
+	sti();
+	monitor_write("Tasking set up\n");
+}
+
+static struct thread *thread_next() {
+	if (current_thread == 0 || current_thread == idle_thread) current_thread = threads;
+	struct thread *ret = current_thread;
+	while (1) {
+		ret = ret->next;
+		if (ret == 0) ret = threads;
+		if (thread_runnable(ret)) {
+		   return ret;
+		}
+		if (ret == current_thread) return idle_thread;
+	}
+}
+
+void tasking_switch() {
+	if (threads == 0) PANIC("No more threads to run !");
+	asm volatile("cli");
+
+	uint32_t esp, ebp, eip;
+
+	asm volatile("mov %%esp, %0" : "=r"(esp));
+	asm volatile("mov %%ebp, %0" : "=r"(ebp));
+	eip = read_eip();
+
+	if (eip == 0x12345) {
+		return;
+	}
+
+	if (current_thread != 0) {
+		current_thread->esp = esp;
+		current_thread->ebp = ebp;
+		current_thread->eip = eip;
+	}
+
+	current_thread = thread_next();
+
+	asm volatile("			\
+			mov %0, %%ebp;	\
+			mov %1, %%esp;	\
+			mov %2, %%ecx;	\
+			mov $0x12345, %%eax;	\
+			jmp *%%ecx;"
+		: : "r"(current_thread->ebp), "r"(current_thread->esp), "r"(current_thread->eip));
+}
+
+void tasking_updateKernelPagetable(uint32_t idx, struct page_table *table, uint32_t tablephysical) {
+	if (idx < 896) return;
+	struct process* it = processes;
+	while (it != 0) {
+		it->pagedir->tables[idx] = table;
+		it->pagedir->tablesPhysical[idx] = tablephysical;
+		it = it->next;
+	}
+}
+
+uint32_t tasking_handleException(struct registers *regs) {
+	if (current_thread == 0) return 0;	//No tasking yet
+	monitor_write("\n(task.c:99) Unhandled exception : ");
+	char *exception_messages[] = {"Division By Zero","Debug","Non Maskable Interrupt","Breakpoint",
+    "Into Detected Overflow","Out of Bounds","Invalid Opcode","No Coprocessor", "Double Fault",
+    "Coprocessor Segment Overrun","Bad TSS","Segment Not Present","Stack Fault","General Protection Fault",
+    "Page Fault","Unknown Interrupt","Coprocessor Fault","Alignment Check","Machine Check"};
+	monitor_write(exception_messages[regs->int_no]);
+	monitor_write(" at "); monitor_writeHex(regs->eip);
+	monitor_write(" >>> Thread exiting.\n");
+	thread_exit_stackJmp(EX_TH_EXCEPTION);
+	PANIC("This should never have happened. Please report this.");
+}
+
+void thread_sleep(uint32_t msecs) {
+	if (current_thread == 0) return;
+	current_thread->state = TS_SLEEPING;
+	current_thread->timeWait = timer_time() + msecs;
+	asm volatile("int $64" : : "a"(1));
+}
+
+void thread_exit2(uint32_t reason) {		//See EX_TH_* defines in task.h
+	/*
+	 * if reason == EX_TH_NORMAL, it is just one thread exiting because it has to
+	 * if reason == EX_TH_EXCEPTION, it is just one thread exiting because of an exception
+	 * if reason is none of the two cases above, it is the whole process exiting (with error code = reason)
+	 */
+	struct thread *th = current_thread;
+	struct process *pr = th->process;
+	if ((reason == EX_TH_NORMAL || reason == EX_TH_EXCEPTION) && pr->threads > 1) {
+		thread_delete(th);
+	} else {
+		process_delete(pr);
+	}
+	sti();
+	tasking_switch();
+}
+
+void thread_exit_stackJmp(uint32_t reason) {
+	uint32_t *stack;
+	cli();
+	stack = tasking_tmpStack + 0x4000;
+	stack--; *stack = reason;
+	stack--; *stack = 0;
+	asm volatile("			\
+			mov %0, %%esp;	\
+			mov %1, %%ebp;	\
+			mov %2, %%ecx;	\
+			mov %3, %%cr3;	\
+			jmp *%%ecx;" : :
+			"r"(stack), "r"(stack), "r"(thread_exit2), "r"(kernel_pagedir->physicalAddr));
+}
+
+void thread_exit() {
+	thread_exit_stackJmp(EX_TH_NORMAL);
+}
+
+void process_exit(uint32_t retval) {
+	if (retval == EX_TH_NORMAL || retval == EX_TH_EXCEPTION) retval = EX_PR_EXCEPTION;
+	thread_exit_stackJmp(retval);
+}
+
+static uint32_t thread_runnable(struct thread *t) {
+	if (t->state == TS_RUNNING) return 1;
+	if (t->state == TS_SLEEPING && timer_time() >= t->timeWait) return 1;
+	return 0;
+}
+
+static void thread_run(struct thread *thread, thread_entry entry_point, void *data) {
+	pagedir_switch(thread->process->pagedir);	//TODO : take into account privilege level
+	asm volatile("sti");
+	entry_point(data);
+	thread_exit(0);
+}
+
+struct thread *thread_new(struct process *proc, thread_entry entry_point, void *data) {
+	struct thread *t = kmalloc(sizeof(struct thread));
+	t->process = proc;
+	proc->threads++;
+	t->kernelStack_addr = kmalloc(KSTACKSIZE);
+	t->kernelStack_size = KSTACKSIZE;
+
+	uint32_t *stack = (uint32_t*)((size_t)t->kernelStack_addr + t->kernelStack_size);
+
+	//Pass parameters
+	stack--; *stack = (uint32_t)data;
+	stack--; *stack = (uint32_t)entry_point;	
+	stack--; *stack = (uint32_t)t;
+	stack--; *stack = 0;
+	t->esp = (uint32_t)stack;
+	t->ebp = t->esp + 8;
+	t->eip = (uint32_t)thread_run;
+
+	t->state = TS_RUNNING;
+
+	if (threads == 0) {
+		threads = t;
+	} else {
+		struct thread *i = threads;
+		while (i->next != 0) i = i->next;
+		i->next = t;
+	}
+	return t;
+}
+
+struct process *process_new(struct process* parent, uint32_t uid, uint32_t privilege) {
+	struct process* p = kmalloc(sizeof(struct process));
+	p->pid = (nextpid++);
+	p->uid = uid;
+	p->threads = 0;
+	p->privilege = privilege;
+	p->parent = parent;
+	p->pagedir = pagedir_new();
+	p->next = processes;
+	processes = p;
+	return p;
+}
+
+static void thread_delete(struct thread *th) {
+	kfree(th->kernelStack_addr);
+	th->process->threads--;
+	if (threads == th) {
+		threads = th->next;
+	} else {
+		struct thread *it = threads;
+		while (it->next != th && it->next != 0) it = it->next;
+		if (it->next == th) it->next = th->next;
+	}
+	kfree(th);
+}
+
+static void process_delete(struct process *pr) {
+	struct thread *it;
+	while (threads != 0 && threads->process == pr) thread_delete(threads);
+	it = threads;
+	while (it != 0) {
+		while (it->next->process == pr) thread_delete(it->next);
+		it = it->next;
+	}
+	pagedir_delete(pr->pagedir);
+	if (processes == pr) {
+		processes = pr->next;
+	} else {
+		struct process *it = processes;
+		while (it != 0 && it->next != pr) it = it->next;
+		if (it != 0 && it->next == pr) it->next = pr->next;
+	}
+	kfree(pr);
+}