Function pmap_init

freebsd/arm/arm/pmap-v6.c:1715–1792

* Initialize the pmap module. * Called by vm_init, to initialize any structures that the pmap * system needs to map virtual memory. */

 *  system needs to map virtual memory.
 */
void
pmap_init(void)
{
	vm_size_t s;
	pt2_entry_t *pte2p, pte2;
	u_int i, pte1_idx, pv_npg;

	PDEBUG(1, printf("%s: phys_start = %#x\n", __func__, PHYSADDR));

	/*
	 * Initialize the vm page array entries for kernel pmap's
	 * L2 page table pages allocated in advance.
	 */
	pte1_idx = pte1_index(KERNBASE - PT2MAP_SIZE);
	pte2p = kern_pt2tab_entry(KERNBASE - PT2MAP_SIZE);
	for (i = 0; i < nkpt2pg + NPG_IN_PT2TAB; i++, pte2p++) {
		vm_paddr_t pa;
		vm_page_t m;

		pte2 = pte2_load(pte2p);
		KASSERT(pte2_is_valid(pte2), ("%s: no valid entry", __func__));

		pa = pte2_pa(pte2);
		m = PHYS_TO_VM_PAGE(pa);
		KASSERT(m >= vm_page_array &&
		    m < &vm_page_array[vm_page_array_size],
		    ("%s: L2 page table page is out of range", __func__));

		m->pindex = pte1_idx;
		m->phys_addr = pa;
		pte1_idx += NPT2_IN_PG;
	}

	/*
	 * Initialize the address space (zone) for the pv entries.  Set a
	 * high water mark so that the system can recover from excessive
	 * numbers of pv entries.
	 */
	TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc);
	pv_entry_max = shpgperproc * maxproc + vm_cnt.v_page_count;
	TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max);
	pv_entry_max = roundup(pv_entry_max, _NPCPV);
	pv_entry_high_water = 9 * (pv_entry_max / 10);

	/*
	 * Are large page mappings enabled?
	 */
	TUNABLE_INT_FETCH("vm.pmap.sp_enabled", &sp_enabled);
	if (sp_enabled) {
		KASSERT(MAXPAGESIZES > 1 && pagesizes[1] == 0,
		    ("%s: can't assign to pagesizes[1]", __func__));
		pagesizes[1] = PTE1_SIZE;
	}

	/*
	 * Calculate the size of the pv head table for sections.
	 * Handle the possibility that "vm_phys_segs[...].end" is zero.
	 * Note that the table is only for sections which could be promoted.