void pt_page_in(vaddr_t vaddr, struct segment *s) {
int spl = splhigh();
_vmstats_inc(VMSTAT_TLB_FAULT);
//get the page detail
int pt_offset_id = (vaddr - s->vbase) / PAGE_SIZE;
struct page_detail *pd = &(s->pt->page_details[pt_offset_id]);
if (pd->valid && pd->pfn != -1){
pd->use = 1;
_vmstats_inc(VMSTAT_TLB_RELOAD);
tlb_add_entry(vaddr, pd->pfn*PAGE_SIZE, s->writeable, 1);
splx(spl);
return;
}else if(pd->sfn != -1){
splx(spl);
pd->use = 1;
pd->pfn = cm_getppage();
swap_read(pd->pfn,pd->sfn);
pd->sfn = -1;
//add the tlb entry
tlb_add_entry(vaddr, pd->pfn*PAGE_SIZE, s->writeable, 1);
//finish the load
cm_finish_paging(pd->pfn, pd);
}else{
splx(spl);
pd->use = 1;
pd->pfn = cm_getppage();
load_segment_page(curthread->t_vmspace->file, vaddr, s, pd->pfn*PAGE_SIZE);
//add the tlb entry
tlb_add_entry(vaddr, pd->pfn*PAGE_SIZE, s->writeable, 1);
//finish the load
cm_finish_paging(pd->pfn, pd);
}
}
int16_t whatsUpWithTheFrame(struct virtual_memory_manager *vmm, uint16_t pageNum)
{
int16_t frameNum = -1;
frameNum = tlb_lookup (&vmm->tlb, pageNum);
if (frameNum == -1)
{
//tlb lookup failed
printf ("Page not in TLB. Bummer.\n");
vmm->tlb_miss_count++;
if (vmm->page_table[pageNum].flags & 0x1) //if verification bit, aka if page is loaded
{
vmm->page_found_count++;
frameNum = vmm->page_table[pageNum].frame_number;
tlb_add_entry (&vmm->tlb, pageNum, frameNum);
}
else
{
/* page fault
1. find free frame
2. read page from backing store
3. place read page in frame
4. set page verification flag
*/
printf
("This page seems to be all hidey and not loaded. Let's take care of that...\n");
frameNum = pm_demand_page (&vmm->pm, pageNum);
// pm_backup_frame(&vmm->pm,frameNum,pageNum);
vmm->page_table[pageNum].frame_number = frameNum;
vmm->page_table[pageNum].flags |= 0x1; //page is loaded. set verification bit
vmm->page_fault_count++;
}
}
else {
vmm->tlb_hit_count++;
vmm->page_found_count++;
}
return frameNum;
}