Function pmap_enter_largepage

freebsd/amd64/amd64/pmap.c:6615–6707

#endif /* VM_NRESERVLEVEL > 0 */

static int
pmap_enter_largepage(pmap_t pmap, vm_offset_t va, pt_entry_t newpte, int flags,
    int psind)
{
	vm_page_t mp;
	pt_entry_t origpte, *pml4e, *pdpe, *pde, pten, PG_V;

	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
	KASSERT(psind > 0 && psind < MAXPAGESIZES && pagesizes[psind] != 0,
	    ("psind %d unexpected", psind));
	KASSERT(((newpte & PG_FRAME) & (pagesizes[psind] - 1)) == 0,
	    ("unaligned phys address %#lx newpte %#lx psind %d",
	    newpte & PG_FRAME, newpte, psind));
	KASSERT((va & (pagesizes[psind] - 1)) == 0,
	    ("unaligned va %#lx psind %d", va, psind));
	KASSERT(va < VM_MAXUSER_ADDRESS,
	    ("kernel mode non-transparent superpage")); /* XXXKIB */
	KASSERT(va + pagesizes[psind] < VM_MAXUSER_ADDRESS,
	    ("overflowing user map va %#lx psind %d", va, psind)); /* XXXKIB */

	PG_V = pmap_valid_bit(pmap);

restart:
	if (!pmap_pkru_same(pmap, va, va + pagesizes[psind]))
		return (KERN_PROTECTION_FAILURE);
	pten = newpte;
	if (va < VM_MAXUSER_ADDRESS && pmap->pm_type == PT_X86)
		pten |= pmap_pkru_get(pmap, va);

	if (psind == 2) {	/* 1G */
		pml4e = pmap_pml4e(pmap, va);
		if (pml4e == NULL || (*pml4e & PG_V) == 0) {
			mp = pmap_allocpte_alloc(pmap, pmap_pml4e_pindex(va),
			    NULL, va);
			if (mp == NULL)
				goto allocf;
			pdpe = (pdp_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(mp));
			pdpe = &pdpe[pmap_pdpe_index(va)];
			origpte = *pdpe;
			MPASS(origpte == 0);
		} else {
			pdpe = pmap_pml4e_to_pdpe(pml4e, va);
			KASSERT(pdpe != NULL, ("va %#lx lost pdpe", va));
			origpte = *pdpe;
			if ((origpte & PG_V) == 0) {
				mp = PHYS_TO_VM_PAGE(*pml4e & PG_FRAME);
				mp->ref_count++;
			}
		}
		*pdpe = pten;
	} else /* (psind == 1) */ {	/* 2M */
		pde = pmap_pde(pmap, va);
		if (pde == NULL) {
			mp = pmap_allocpte_alloc(pmap, pmap_pdpe_pindex(va),
			    NULL, va);
			if (mp == NULL)
				goto allocf;
			pde = (pd_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(mp));