void vm_map_page(struct vm_translation_map *map, unsigned int va, unsigned int pa)
{
int vpindex = va / PAGE_SIZE;
int pgdindex = vpindex / 1024;
int pgtindex = vpindex % 1024;
unsigned int *pgdir;
unsigned int *pgtbl;
struct list_node *other_map;
unsigned int new_pgt;
int old_flags;
if (va >= KERNEL_BASE)
{
// Map into kernel space
old_flags = acquire_spinlock_int(&kernel_space_lock);
// The page tables for kernel space are shared by all page directories.
// Check the first page directory to see if this is present. If not,
// allocate a new one and stick it into all page directories.
pgdir = (unsigned int*) PA_TO_VA(kernel_map.page_dir);
if ((pgdir[pgdindex] & PAGE_PRESENT) == 0)
{
new_pgt = page_to_pa(vm_allocate_page()) | PAGE_PRESENT;
list_for_each(&map_list, other_map, struct list_node)
{
pgdir = (unsigned int*) PA_TO_VA(((struct vm_translation_map*)other_map)->page_dir);
pgdir[pgdindex] = new_pgt;
}
}
void destroy_translation_map(struct vm_translation_map *map)
{
int i;
unsigned int *pgdir;
int old_flags;
old_flags = acquire_spinlock_int(&kernel_space_lock);
list_remove_node(map);
release_spinlock_int(&kernel_space_lock, old_flags);
// Free user space page tables
pgdir = (unsigned int*) PA_TO_VA(map->page_dir);
for (i = 0; i < 768; i++)
{
if (pgdir[i] & PAGE_PRESENT)
dec_page_ref(pa_to_page(PAGE_ALIGN(pgdir[i])));
}
dec_page_ref(pa_to_page(map->page_dir));
slab_free(&translation_map_slab, map);
}
struct vm_translation_map *create_translation_map(void)
{
struct vm_translation_map *map;
int old_flags;
map = slab_alloc(&translation_map_slab);
map->page_dir = page_to_pa(vm_allocate_page());
old_flags = acquire_spinlock_int(&kernel_space_lock);
// Copy kernel page tables into new page directory
memcpy((unsigned int*) PA_TO_VA(map->page_dir) + 768,
(unsigned int*) PA_TO_VA(kernel_map.page_dir) + 768,
256 * sizeof(unsigned int));
map->asid = next_asid++;
map->lock = 0;
list_add_tail(&map_list, (struct list_node*) map);
release_spinlock_int(&kernel_space_lock, old_flags);
return map;
}
INTERNAL err_code __sleep_in_mutex(struct mutex *mutex) {
struct __mutex_node *node = NULL;
bool acquired;
acquire_spinlock(&mutex->ilock, 0);
acquired = acquire_spinlock_int(&mutex->mlock, 1);
if (!acquired) {
node = alloc_block(&mutex_node_pool);
if (node) {
node->next = NULL;
node->id = get_thread();
if (mutex->head)
mutex->head->next = node;
mutex->head = node;
if (!mutex->tail)
mutex->tail = node;
pause_this_thread(&mutex->ilock);
}
}
if (!node)
release_spinlock(&mutex->ilock);
return (acquired || node) ? ERR_NONE : ERR_OUT_OF_MEMORY;
}