static void pt_release_pml4(pte_t *pml4, virt_t from, virt_t to)
{
virt_t vaddr = from;
for (int i = pml4_i(from); vaddr != to; ++i) {
const pte_t pte = pml4[i];
const virt_t bytes =
MINU(PML3_SIZE - (vaddr & PML3_MASK), to - vaddr);
const pfn_t pages = bytes >> PAGE_BITS;
if (pte_present(pte)) {
const phys_t paddr = pte_phys(pte);
const pfn_t pfn = paddr >> PAGE_BITS;
struct page *pt = pfn2page(pfn);
pt_release_pml3(va(paddr), vaddr, vaddr + bytes);
pt->u.refcount -= pages;
if (pt->u.refcount == 0) {
pml4[i] = 0;
free_page_table(pt);
}
}
vaddr += bytes;
}
}
static int pt_populate_pml2(pte_t *pml2, virt_t from, virt_t to, pte_t flags)
{
virt_t vaddr = from;
for (int i = pml2_i(from); vaddr != to; ++i) {
const virt_t bytes =
MINU(PML1_SIZE - (vaddr & PML1_MASK), to - vaddr);
const pfn_t pages = bytes >> PAGE_BITS;
if (!pte_present(pml2[i]) && !pte_large(flags)) {
struct page *pt = alloc_page_table(flags);
if (!pt) {
pt_release_pml2(pml2, from, vaddr);
return -ENOMEM;
}
pt->u.refcount += pages;
pml2[i] = page_paddr(pt) | flags;
} else if (pte_present(pml2[i]) && !pte_large(pml2[i])) {
const pfn_t pfn = pte_phys(pml2[i]) >> PAGE_BITS;
struct page *pt = pfn2page(pfn);
pt->u.refcount += pages;
}
vaddr += bytes;
}
return 0;
}
static struct kmem_slab *kmem_get_slab(void *ptr)
{
const pfn_t pfn = PA(ptr) >> PAGE_BITS;
return pfn2page(pfn)->u.slab;
}
