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#include <apos/string.h>
#include <apos/pmem.h>
#include <apos/vmem.h>
#include <apos/mem.h>
#include <apos/debug.h>
#include <pages.h>
#include <vmem.h>
#define pte_ppn(pte) (((pm_t)(pte)) >> 10)
#define pte_flags(pte) (((pm_t)(pte)) & 0xff)
#define to_pte(p, f) ((pm_to_pnum((pm_t)__pa(p)) << 10) | (f))
#define pte_addr(pte) __va(pnum_to_paddr(pte_ppn(pte)))
#define pte_paddr(pte) (pnum_to_paddr(pte_ppn(pte)))
#define vm_to_index(a, o) (pm_to_index(a, o))
#define is_active(pte) (pte_flags(pte) & VM_V)
#define is_leaf(pte) (is_active(pte) && (pte_flags(pte) & ~VM_V))
#define is_branch(pte) (is_active(pte) && !(pte_flags(pte) & ~VM_V))
static pm_t *__find_vmem(struct vm_branch_t *b, vm_t v, enum mm_order_t *o)
{
enum mm_order_t top = __mm_max_order;
if(o)
*o = MM_O0;
do {
size_t idx = vm_to_index(v, top);
pm_t pte = (pm_t)b->leaf[idx];
if(!pte)
return 0;
if(is_leaf(pte)){
if(o)
*o = top;
return (pm_t *)&b->leaf[idx];
}
b = (struct vm_branch_t *)pte_addr(pte);
} while (top--);
return 0;
}
int mod_vmem(struct vm_branch_t *branch, vm_t vaddr, pm_t paddr, uint8_t flags)
{
pm_t *pte = __find_vmem(branch, vaddr, 0);
if(pte){
*pte = to_pte(paddr, flags);
return 0;
}
return -1;
}
/* huh, should probably add status flags etc. to all my API functions. Damn, I'm
* lazy. */
int stat_vmem(struct vm_branch_t *branch, vm_t vaddr, pm_t *paddr,
enum mm_order_t *order, uint8_t *flags)
{
pm_t *pte = __find_vmem(branch, vaddr, order);
if(pte){
if(paddr)
*paddr = (pm_t)pte_addr(*pte);
if(flags)
*flags = pte_flags(*pte);
return 0;
}
return -1;
}
static struct vm_branch_t *__create_leaf()
{
pm_t new_leaf = alloc_page(MM_KPAGE, 0);
memset((void *)new_leaf, 0, sizeof(struct vm_branch_t));
return (struct vm_branch_t *)to_pte(new_leaf, VM_V);
}
static void __destroy_branch(struct vm_branch_t *b)
{
if(!b)
return;
for(size_t i = 0; i < BASE_PAGE_SIZE / sizeof(pm_t); ++i){
if(is_branch(b->leaf[i]))
__destroy_branch((struct vm_branch_t *)pte_addr(b->leaf[i]));
free_page(MM_KPAGE, (pm_t)pte_addr(b->leaf[i]));
}
}
void map_vmem(struct vm_branch_t *branch,
pm_t paddr, vm_t vaddr, uint8_t flags, enum mm_order_t order)
{
enum mm_order_t top = __mm_max_order;
while (top != order) {
size_t idx = vm_to_index(vaddr, top);
if (!branch->leaf[idx])
branch->leaf[idx] = __create_leaf();
branch = (struct vm_branch_t *)pte_addr(branch->leaf[idx]);
top--;
}
size_t idx = vm_to_index(vaddr, top);
if (is_branch(branch->leaf[idx])) /* something has gone terribly wrong */
__destroy_branch(branch->leaf[idx]);
branch->leaf[idx] = (struct vm_branch_t *)to_pte(paddr, flags);
}
void unmap_vmem(struct vm_branch_t *branch, vm_t vaddr)
{
pm_t *pte = __find_vmem(branch, vaddr, 0);
if(pte)
*pte = 0;
}
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