/*
* Preallocate some pages:
* some 2M ones will be used by the first process.
* some 1G ones will be allocated for each domain so processes may use them.
*/
void
pageinit(void)
{
int si, i, color;
Page *pg;
pga.userinit = 1;
DBG("pageinit: npgsz = %d\n", sys->npgsz);
/*
* Don't pre-allocate 4K pages, we are not using them anymore.
*/
for(si = 1; si < sys->npgsz; si++){
for(i = 0; i < Nstartpgs; i++){
if(si < 2)
color = -1;
else
color = i;
pg = pgalloc(sys->pgsz[si], color);
if(pg == nil){
DBG("pageinit: pgalloc failed. breaking.\n");
break; /* don't consume more memory */
}
DBG("pageinit: alloced pa %#P sz %#ux color %d\n",
pg->pa, sys->pgsz[si], pg->color);
lock(&pga.l);
pg->ref = 0;
pagechainhead(pg);
unlock(&pga.l);
}
}
pga.userinit = 0;
}
static int
tryalloc(int pgszi, int color)
{
Page *p;
p = pgalloc(sys->pgsz[pgszi], color);
if(p != nil){
lock(&pga);
pagechainhead(p);
unlock(&pga);
return 0;
}
return -1;
}
/*
* given the current proc's page directory, find the pte where
* the virtual address lied in. If the 'creat' parameter is set,
* allocate a page as middle page table and always success.
* */
struct pte* find_pte(struct pde *pgd, uint vaddr, uint creat){
struct pde *pde;
struct pte *pt;
struct page *pg;
uint pn;
if (vaddr < KMEM_END) {
panic("find_pte(): don't touch kernel's address space.");
}
pde = &pgd[PDX(vaddr)];
if ((pde->pd_flag & PTE_P)==0) {
if (creat==0) {
return NULL;
}
pg = pgalloc();
pde->pd_flag = PTE_P | PTE_U | PTE_W;
pde->pd_off = pg->pg_num;
pt = (struct pte*)(pde->pd_off * PAGE);
memset(pt, 0, PAGE);
flmmu();
}
pt = (struct pte*)(pde->pd_off * PAGE);
return &pt[PTX(vaddr)];
}
FAR void *mm_sbrk(FAR struct mm_heap_s *heap, intptr_t incr,
uintptr_t maxbreak)
{
uintptr_t brkaddr;
uintptr_t allocbase;
unsigned int pgincr;
size_t bytesize;
int err;
DEBUGASSERT(incr >= 0);
if (incr < 0)
{
err = ENOSYS;
goto errout;
}
/* Get the current break address (NOTE: assumes region 0). If
* the memory manager is uninitialized, mm_brkaddr() will return
* zero.
*/
brkaddr = (uintptr_t)mm_brkaddr(heap, 0);
if (incr > 0)
{
/* Convert the increment to multiples of the page size */
pgincr = MM_NPAGES(incr);
/* Check if this increment would exceed the maximum break value */
if ((brkaddr > 0) && ((maxbreak - brkaddr) < (pgincr << MM_PGSHIFT)))
{
err = ENOMEM;
goto errout;
}
/* Allocate the requested number of pages and map them to the
* break address. If we provide a zero brkaddr to pgalloc(), it
* will create the first block in the correct virtual address
* space and return the start address of that block.
*/
allocbase = pgalloc(brkaddr, pgincr);
if (allocbase == 0)
{
err = EAGAIN;
goto errout;
}
/* Has the been been initialized? brkaddr will be zero if the
* memory manager has not yet been initialized.
*/
bytesize = pgincr << MM_PGSHIFT;
if (brkaddr != 0)
{
/* No... then initialize it now */
mm_initialize(heap, (FAR void *)allocbase, bytesize);
}
else
{
/* Extend the heap (region 0) */
mm_extend(heap, (FAR void *)allocbase, bytesize, 0);
}
}
return (FAR void *)brkaddr;
errout:
set_errno(err);
return (FAR void *)-1;
}
/*
* can be called with up == nil during boot.
*/
Page*
newpage(int clear, Segment **s, uintptr_t va, usize size, int color)
{
Page *p;
KMap *k;
uint8_t ct;
Pgsza *pa;
int i, dontalloc, si;
// static int once;
si = getpgszi(size);
//iprint("(remove this print and diea)newpage, size %x, si %d\n", size, si);
pa = &pga.pgsza[si];
lock(&pga.l);
/*
* Beware, new page may enter a loop even if this loop does not
* loop more than once, if the segment is lost and fault calls us
* again. Either way, we accept any color if we failed a couple of times.
*/
for(i = 0;; i++){
if(i > 3)
color = NOCOLOR;
/*
* 1. try to reuse a free one.
*/
p = findpg(pa->head, color);
if(p != nil)
break;
/*
* 2. try to allocate a new one from physical memory
*/
p = pgalloc(size, color);
if(p != nil){
pagechainhead(p);
break;
}
/*
* 3. out of memory, try with the pager.
* but release the segment (if any) while in the pager.
*/
unlock(&pga.l);
dontalloc = 0;
if(s && *s) {
qunlock(&((*s)->lk));
*s = 0;
dontalloc = 1;
}
/*
* Try to get any page of the desired color
* or any color for NOCOLOR.
*/
kickpager(si, color);
/*
* If called from fault and we lost the segment from
* underneath don't waste time allocating and freeing
* a page. Fault will call newpage again when it has
* reacquired the segment locks
*/
if(dontalloc)
return 0;
lock(&pga.l);
}
assert(p != nil);
ct = PG_NEWCOL;
pageunchain(p);
lock(&p->l);
if(p->ref != 0)
panic("newpage pa %#ullx", p->pa);
uncachepage(p);
p->ref++;
p->va = va;
p->modref = 0;
for(i = 0; i < nelem(p->cachectl); i++)
p->cachectl[i] = ct;
unlock(&p->l);
unlock(&pga.l);
if(clear) {
k = kmap(p);
if (VA(k) == 0xfffffe007d800000ULL) trip++;
// if (trip) die("trip before memset");
// This will frequently die if we use 3K-1 (3071 -- 0xbff)
// it will not if we use 3070.
// The fault is a null pointer deref.
//memset((void*)VA(k), 0, machp()->pgsz[p->pgszi]);
// thinking about it, using memset is stupid.
// Don't get upset about this loop;
// we make it readable, compilers optimize it.
int i;
uint64_t *v = (void *)VA(k);
if (1)
for(i = 0; i < sys->pgsz[p->pgszi]/sizeof(*v); i++)
v[i] = 0;
//if (trip) die("trip");
kunmap(k);
}
DBG("newpage: va %#p pa %#ullx pgsz %#ux color %d\n",
p->va, p->pa, sys->pgsz[p->pgszi], p->color);
return p;
}