// Free a page table and all the physical memory pages
// in the user part.
void freevm (pgd_t *pgdir)
{
uint i,j;
char *v;
pmd_t *pmdbase;
if (pgdir == 0) {
panic("freevm: no pgdir");
}
// release the user space memroy, but not page tables
deallocuvm(pgdir, UADDR_SZ, 0);
// release the page tables
for(j = 0; j < PTRS_PER_PGD; j++) {
if(pgdir[j] & (ENTRY_TABLE | ENTRY_VALID)) {
pmdbase = (pmd_t*) p2v(pgdir[j] & PG_ADDR_MASK);
for (i = 0; i < PTRS_PER_PMD; i++) {
if (pmdbase[i] & (ENTRY_TABLE | ENTRY_VALID)) {
v = p2v(PT_ADDR(pmdbase[i]));
kpt_free(v);
}
}
kpt_free((char*) pmdbase);
}
}
kpt_free((char*) pgdir);
}
static void walk_pagetable(uint64_t max_addr) {
uint32_t pml4 = PML4(0);
int dbg = 0;
if (dbg) {
printk("pml4pgs: %d\n", NUM_PML4PGS(max_addr));
printk("pdppgs: %d\n", NUM_PDPPGS(max_addr));
printk("pdpgs: %d\n", NUM_PDPGS(max_addr));
printk("ptpgs: %d\n", NUM_PTPGS(max_addr));
printk("pml4(0) is at 0x%lx\n", PML4(0));
printk("pml4e(0) is 0x%llx ", PT_ADDR(*(uint64_t *)pml4));
printk("should be 0x%llx\n", PML4E(0));
}
assert(PT_ADDR(*(uint64_t *)pml4) == PML4E(0));
uint64_t *pdp, *pd, *pt;
size_t i, j, k;
for (i = 0; i < NUM_ENTRIES; i++) {
pdp = (uint64_t *)(PT_ADDR(*(uint64_t *)pml4)) + i;
if (!(*pdp & 0x1))
continue;
if (dbg) {
printk("PDP(%d) is at ", i);
printk("0x%llx ", pdp);
printk("should be 0x%llx\n", PDP(i));
}
assert((uint32_t)pdp == PDP(i));
if (dbg) {
printk("PDPE(%d) is at ", i);
printk("0x%llx ", PT_ADDR(*pdp));
printk("should be 0x%llx\n", PDPE(i));
}
assert(PT_ADDR(*pdp) == PDPE(i));
for (j = 0; j < NUM_ENTRIES; j++) {
pd = ((uint64_t *)PT_ADDR(*pdp)) + j;
if (!(*pd & 0x1))
continue;
size_t jdx = i * NUM_ENTRIES + j;
if (dbg) {
printk("PD(%d) is at ", jdx);
printk("0x%llx ", pd);
printk("should be 0x%llx\n", PD(jdx));
}
assert((uint32_t)pd == PD(jdx));
if (dbg) {
printk("PDE(%d) is at ", jdx);
printk("0x%llx ", PT_ADDR(*pd));
printk("should be 0x%llx\n", PDE(jdx));
}
assert(PT_ADDR(*pd) == PDE(jdx));
for (k = 0; k < NUM_ENTRIES; k++) {
pt = ((uint64_t *)PT_ADDR(*pd)) + k;
if (!(*pt & 0x1))
continue;
size_t idx = jdx * NUM_ENTRIES + k;
if (dbg) {
printk("PT(%d) is at ", idx);
printk("0x%llx ", pt);
printk("should be 0x%llx\n", PT(idx));
}
assert((uint32_t)pt == PT(idx));
if (dbg) {
printk("PTE(%d) is at ", idx);
printk("0x%llx ", PT_ADDR(*pt));
printk("should be 0x%llx\n", PTE(idx));
}
assert(PT_ADDR(*pt) == PTE(idx));
}
}
}
}
