Function pmap_unmapbios

freebsd/arm64/arm64/pmap.c:5978–6042

}

void
pmap_unmapbios(vm_offset_t va, vm_size_t size)
{
	struct pmap_preinit_mapping *ppim;
	vm_offset_t offset, tmpsize, va_trunc;
	pd_entry_t *pde;
	pt_entry_t *l2;
	int i, lvl, l2_blocks, block;
	bool preinit_map;

	l2_blocks =
	   (roundup2(va + size, L2_SIZE) - rounddown2(va, L2_SIZE)) >> L2_SHIFT;
	KASSERT(l2_blocks > 0, ("pmap_unmapbios: invalid size %lx", size));

	/* Remove preinit mapping */
	preinit_map = false;
	block = 0;
	for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) {
		ppim = pmap_preinit_mapping + i;
		if (ppim->va == va) {
			KASSERT(ppim->size == size,
			    ("pmap_unmapbios: size mismatch"));
			ppim->va = 0;
			ppim->pa = 0;
			ppim->size = 0;
			preinit_map = true;
			offset = block * L2_SIZE;
			va_trunc = rounddown2(va, L2_SIZE) + offset;

			/* Remove L2_BLOCK */
			pde = pmap_pde(kernel_pmap, va_trunc, &lvl);
			KASSERT(pde != NULL,
			    ("pmap_unmapbios: Invalid page entry, va: 0x%lx",
			    va_trunc));
			l2 = pmap_l1_to_l2(pde, va_trunc);
			pmap_clear(l2);

			if (block == (l2_blocks - 1))
				break;
			block++;
		}
	}
	if (preinit_map) {
		pmap_invalidate_all(kernel_pmap);
		return;
	}

	/* Unmap the pages reserved with kva_alloc. */
	if (vm_initialized) {
		offset = va & PAGE_MASK;
		size = round_page(offset + size);
		va = trunc_page(va);

		pde = pmap_pde(kernel_pmap, va, &lvl);
		KASSERT(pde != NULL,
		    ("pmap_unmapbios: Invalid page entry, va: 0x%lx", va));
		KASSERT(lvl == 2, ("pmap_unmapbios: Invalid level %d", lvl));