arch_faults.c

newos is new operation system

/* 
** Copyright 2001, Travis Geiselbrecht. All rights reserved.
** Distributed under the terms of the NewOS License.
*/
#include <kernel/kernel.h>
#include <kernel/faults.h>
#include <kernel/faults_priv.h>
#include <kernel/vm.h>
#include <kernel/debug.h>
#include <kernel/console.h>
#include <kernel/int.h>

#include <kernel/arch/cpu.h>
#include <kernel/arch/int.h>
#include <kernel/arch/faults.h>

#include <kernel/arch/i386/interrupts.h>
#include <kernel/arch/i386/faults.h>

#include <boot/stage2.h>

#include <string.h>

// XXX this module is largely outdated. Will probably be removed later.

int arch_faults_init(kernel_args *ka)
{
	return 0;
}

int i386_general_protection_fault(int errorcode)
{
	return general_protection_fault(errorcode);
}

int i386_double_fault(int errorcode)
{
	kprintf("double fault! errorcode = 0x%x\n", errorcode);
	dprintf("double fault! errorcode = 0x%x\n", errorcode);
	for(;;);
	return INT_NO_RESCHEDULE;
}

int i386_device_not_available(void)
{
	cpu_ent *cpu = get_curr_cpu_struct();
	struct thread *t = thread_get_current_thread();

//	dprintf("***device_not_available: cpu %d holds fpu context for thread %d. current thread %d, state on cpu %d\n", 
//		cpu->cpu_num, 
//		cpu->fpu_state_thread ? cpu->fpu_state_thread->id : -1, 
//		t->id, 
//		t->fpu_cpu ? t->fpu_cpu->cpu_num : -1);

	// unset the task switched bit
	i386_clear_task_switched();

	// if our cpu owns the fpu context of the current thread, then we're done
	if(cpu->fpu_state_thread 
	   && cpu->fpu_state_thread == t 
	   && t->fpu_state_saved == false)
		return 0;

	// save the current fpu context
	if(cpu->fpu_state_thread) {
		ASSERT(cpu->fpu_state_thread->fpu_cpu == cpu);
		ASSERT(cpu->fpu_state_thread->fpu_state_saved == false);
		i386_save_fpu_context(&cpu->fpu_state_thread->arch_info.fpu_state);
		cpu->fpu_state_thread->fpu_state_saved = true;
		cpu->fpu_state_thread->fpu_cpu = NULL;
		cpu->fpu_state_thread = NULL;
	}

	// load the new context
	ASSERT(cpu->fpu_state_thread == NULL);
	ASSERT(t->fpu_cpu == NULL);
	i386_load_fpu_context(t->arch_info.fpu_state);
	t->fpu_state_saved = false;
	t->fpu_cpu = cpu;
	t->fpu_cpu->fpu_state_thread = t;

//	panic("device not available\n");

	return 0;
}