void destroy_area(struct vm_address_space *space, struct vm_area *area)
{
struct vm_cache *cache;
unsigned int va;
unsigned int ptentry;
rwlock_lock_write(&space->mut);
cache = area->cache;
// Unmap all pages in this area
for (va = area->low_address; va < area->high_address; va += PAGE_SIZE)
{
ptentry = query_translation_map(space->translation_map, va);
if ((ptentry & PAGE_PRESENT) != 0)
{
VM_DEBUG("destroy_area: decrementing page ref for va %08x pa %08x\n",
va, PAGE_ALIGN(ptentry));
dec_page_ref(pa_to_page(ptentry));
}
}
destroy_vm_area(area);
rwlock_unlock_write(&space->mut);
if (cache)
dec_cache_ref(cache);
}
struct page *pgt_get_task_page(struct task_page_table *table,
unsigned long base)
{
unsigned long pte;
struct page *page;
/*
* get the virtual address of the pte entry
*/
pte = pgt_get_pte_addr(table->pde_base, base);
if (!pte)
return NULL;
/*
* translate the pte entry to physical address
*/
pte = mmu_pte_entry_to_pa(pte);
/*
* user page can only use pa_to_page can not use
* va_to_page
*/
page = pa_to_page(pte);
return page;
}
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);
}
static inline struct page *
pgt_get_pte_page(unsigned long base, unsigned long mbase)
{
unsigned long pde, pte;
struct page *page;
pde = pgt_get_pde_entry_addr(base, mbase);
pte = mmu_pde_entry_to_pa(pde);
if (!pte)
return NULL;
page = pa_to_page(pte);
return page;
}
static inline unsigned long
pgt_get_pte_addr(unsigned long base,
unsigned long map_address)
{
unsigned long pde, pte;
struct page *page;
pde = pgt_get_pde_entry_addr(base, map_address);
pte = mmu_pde_entry_to_pa(pde);
if (!pte)
return 0;
page = pa_to_page(pte);
pte = page_to_va(page);
return pgt_get_pte_entry_addr(pte, map_address);
}
struct page *
pgt_unmap_mmap_page(struct task_page_table *table,
unsigned long base)
{
unsigned long pte;
struct page *page;
struct page *pte_page;
pte_page = pgt_get_pte_page(table->pde_base, base);
if (!pte_page)
return NULL;
pte = pgt_get_pte_entry_addr(page_to_va(pte_page), base);
page = pa_to_page(mmu_pte_entry_to_pa(pte));
mmu_clear_pte_entry(pte);
return page;
}
static unsigned long
pgt_get_mapped_pte_addr(struct task_page_table *table,
unsigned long map_address)
{
unsigned long pde, pte;
struct page *page;
pde = pgt_get_pde_entry_addr(table->pde_base, map_address);
pte = mmu_pde_entry_to_pa(pde);
if (!pte) {
page = pgt_map_new_pde_entry(&table->task_list,
table->pde_base, map_address);
if (!page)
return 0;
} else {
page = pa_to_page(pte);
}
return pgt_get_pte_entry_addr(page_to_va(page), map_address);
}
