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#include <vm.h>
#include <stddef.h>
#include <kalloc.h>
#include <stdio.h>
#include <asm.h>
pagetable_t *kpt;
#define VPN(vaddr, level) \
(((uintptr_t)vaddr >> (12 + (9 * level))) & 0x1ff)
#define PPN(paddr, level) \
(((uintptr_t)paddr >> (12 + (9 * level))) & \
((level == 2) ? 0x3ffffff : 0x1ff))
void
kptinit(void)
{
kpt = kzalloc();
}
void
kptinithart(void)
{
FLUSH_TLB();
write_satp(MODE_SV39, (uintptr_t)kpt);
FLUSH_TLB();
}
void
vmap(pagetable_t *root, uintptr_t vaddr, uintptr_t paddr, int bits, int level)
{
if (pte_is_branch(bits))
printf("error: pte_is_branch\n"); return;
pt_entry_t *e = walkpt(root, vaddr, 1);
if (pte_is_valid(*e))
printf("warning: mapping already exists for this address\n");
*e = PA2PTE(paddr) | PAGEBITS_VALID | bits;
}
pt_entry_t *
walkpt(pagetable_t *root, uintptr_t vaddr, int alloc) {
pt_entry_t *pt = root->entries;
for (int level = 2; level > 0; level--) {
pt_entry_t *e = &pt[VPN(vaddr, level)];
if (!pte_is_valid(*e)) {
if (!alloc)
return NULL;
pt = kzalloc();
*e = PA2PTE(pt) | PAGEBITS_VALID;
continue;
}
pt = (pt_entry_t *)PTE2PA(*e);
}
/* now we should be at level 0, and e should point to our entry */
return &pt[VPN(vaddr, 0)];
}
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