struct pt_iter *pt_iter_set(struct pt_iter *iter, pte_t *pml4, virt_t addr)
{
memset(iter, 0, sizeof(*iter));
if (!pml4)
return iter;
int level = PT_MAX_LEVEL;
int idx = pml4_i(addr);
pte_t pte = pml4[idx];
iter->pt[level] = pml4;
iter->idx[level] = idx;
while (pte_present(pte) && level != 0 && !pte_large(pte)) {
const phys_t paddr = pte_phys(pte);
pte_t *pt = va(paddr);
idx = pt_index(addr, level--);
pte = pt[idx];
iter->idx[level] = idx;
iter->pt[level] = pt;
}
iter->addr = pt_iter_addr(iter);
iter->level = level;
return iter;
}
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;
}
}
phys_t get_phys_adr(virt_t vad) {
phys_t pad;
pte_t *pml4e = pml4 + pml4_i(vad);
pte_t *pdpte = ((pte_t *) va(pte_phys(*pml4e) << 12)) + pml3_i(vad);
pte_t *pde = ((pte_t *) va(pte_phys(*pdpte) << 12)) + pml2_i(vad);
if (pte_large(*pde)) {
pad = ((*pde & (~((1 << 21) - 1)))) | (vad & ((1 << 21) - 1));
return pad;
}
pte_t *pte = ((pte_t *) va(pte_phys(*pde) << 12)) + pml1_i(vad);
pad = ((*pte & (~((1 << 12) - 1)))) | (vad & ((1 << 12) - 1));;
return pad;
}
static int pt_populate_pml4(pte_t *pml4, virt_t from, virt_t to, pte_t flags)
{
virt_t vaddr = from;
for (int i = pml4_i(from); vaddr < to; ++i) {
struct page *pt;
phys_t paddr;
const virt_t bytes =
MINU(PML3_SIZE - (vaddr & PML3_MASK), to - vaddr);
const pfn_t pages = bytes >> PAGE_BITS;
if (!pte_present(pml4[i])) {
pt = alloc_page_table(flags);
if (!pt) {
pt_release_pml4(pml4, from, vaddr);
return -ENOMEM;
}
paddr = page_paddr(pt);
pml4[i] = paddr | (flags & ~PTE_LARGE);
} else {
const pte_t pte = pml4[i];
paddr = pte_phys(pte);
pt = pfn2page(paddr >> PAGE_BITS);
}
pt->u.refcount += pages;
const int rc = pt_populate_pml3(va(paddr), vaddr, vaddr + bytes,
flags);
if (rc) {
pt_release_pml4(pml4, from, vaddr);
pt->u.refcount -= pages;
if (pt->u.refcount == 0) {
pml4[i] = 0;
free_page_table(pt);
}
return rc;
}
vaddr += bytes;
}
return 0;
}
static int pt_index(virt_t vaddr, int level)
{
switch (level) {
case 4:
return pml4_i(vaddr);
case 3:
return pml3_i(vaddr);
case 2:
return pml2_i(vaddr);
case 1:
return pml1_i(vaddr);
}
DBG_ASSERT(0 && "Unreachable");
return 0;
}
void map_adr(virt_t vad, phys_t pad, int flags) {
if (flags & USE_BIG_PAGE) {
assert((vad & ((1 << (12 + 9)) - 1)) == 0);
assert((pad & ((1 << (12 + 9)) - 1)) == 0);
} else {
assert((vad & ((1 << (12)) - 1)) == 0);
assert((pad & ((1 << (12)) - 1)) == 0);
}
pte_t *pml4e = pml4 + pml4_i(vad);
force_pte(pml4e, flags);
pte_t *pdpte = ((pte_t *) va(pte_phys(*pml4e) << 12)) + pml3_i(vad);
force_pte(pdpte, flags);
pte_t *pde = ((pte_t *) va(pte_phys(*pdpte) << 12)) + pml2_i(vad);
if (flags & USE_BIG_PAGE) {
assert(pte_present(*pde) == false);
*pde = pad | PTE_PRESENT | PTE_WRITE | PTE_LARGE;
flush_tlb_addr(vad);
return;
}
force_pte(pde, flags);
pte_t *pte = ((pte_t *) va(pte_phys(*pde) << 12)) + pml1_i(vad);
assert(pte_present(*pte) == false);
*pte = pad | PTE_PRESENT | PTE_WRITE;
if (!(flags & NOT_FLUSH_TLB)) {
flush_tlb_addr(vad);
}
}
