ref: 7186be0424ba65942a13b7706017c6ef4338f219
dir: /sys/src/9/bcm64/mmu.c/
#include "u.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
#include "fns.h"
#include "sysreg.h"
void
mmu0init(uintptr *l1)
{
uintptr va, pa, pe;
/* 0 identity map */
pe = PHYSDRAM + soc.dramsize;
for(pa = PHYSDRAM; pa < pe; pa += PGLSZ(1))
l1[PTL1X(pa, 1)] = pa | PTEVALID | PTEBLOCK | PTEWRITE | PTEAF
| PTEKERNEL | PTESH(SHARE_INNER);
if(PTLEVELS > 2)
for(pa = PHYSDRAM; pa < pe; pa += PGLSZ(2))
l1[PTL1X(pa, 2)] = (uintptr)&l1[L1TABLEX(pa, 1)] | PTEVALID | PTETABLE;
if(PTLEVELS > 3)
for(pa = PHYSDRAM; pa < pe; pa += PGLSZ(3))
l1[PTL1X(pa, 3)] = (uintptr)&l1[L1TABLEX(pa, 2)] | PTEVALID | PTETABLE;
/* KZERO */
for(pa = PHYSDRAM, va = KZERO; pa < pe; pa += PGLSZ(1), va += PGLSZ(1))
l1[PTL1X(va, 1)] = pa | PTEVALID | PTEBLOCK | PTEWRITE | PTEAF
| PTEKERNEL | PTESH(SHARE_INNER);
if(PTLEVELS > 2)
for(pa = PHYSDRAM, va = KZERO; pa < pe; pa += PGLSZ(2), va += PGLSZ(2))
l1[PTL1X(va, 2)] = (uintptr)&l1[L1TABLEX(va, 1)] | PTEVALID | PTETABLE;
if(PTLEVELS > 3)
for(pa = PHYSDRAM, va = KZERO; pa < pe; pa += PGLSZ(3), va += PGLSZ(3))
l1[PTL1X(va, 3)] = (uintptr)&l1[L1TABLEX(va, 2)] | PTEVALID | PTETABLE;
/* VIRTIO */
pe = -VIRTIO + soc.physio;
for(pa = soc.physio, va = VIRTIO; pa < pe; pa += PGLSZ(1), va += PGLSZ(1))
l1[PTL1X(va, 1)] = pa | PTEVALID | PTEBLOCK | PTEWRITE | PTEAF
| PTEKERNEL | PTESH(SHARE_OUTER) | PTEDEVICE;
if(PTLEVELS > 2)
for(pa = soc.physio, va = VIRTIO; pa < pe; pa += PGLSZ(2), va += PGLSZ(2))
l1[PTL1X(va, 2)] = (uintptr)&l1[L1TABLEX(va, 1)] | PTEVALID | PTETABLE;
if(PTLEVELS > 3)
for(pa = soc.physio, va = VIRTIO; pa < pe; pa += PGLSZ(3), va += PGLSZ(3))
l1[PTL1X(va, 3)] = (uintptr)&l1[L1TABLEX(va, 2)] | PTEVALID | PTETABLE;
}
void
mmu0clear(uintptr *l1)
{
uintptr va, pa, pe;
pe = PHYSDRAM + soc.dramsize;
if(PTLEVELS > 3)
for(pa = PHYSDRAM, va = KZERO; pa < pe; pa += PGLSZ(3), va += PGLSZ(3)){
if(PTL1X(pa, 3) != PTL1X(va, 3))
l1[PTL1X(pa, 3)] = 0;
}
if(PTLEVELS > 2)
for(pa = PHYSDRAM, va = KZERO; pa < pe; pa += PGLSZ(2), va += PGLSZ(2)){
if(PTL1X(pa, 2) != PTL1X(va, 2))
l1[PTL1X(pa, 2)] = 0;
}
for(pa = PHYSDRAM, va = KZERO; pa < pe; pa += PGLSZ(1), va += PGLSZ(1)){
if(PTL1X(pa, 1) != PTL1X(va, 1))
l1[PTL1X(pa, 1)] = 0;
}
}
void
mmu1init(void)
{
m->mmul1 = mallocalign(L1SIZE+L1TOPSIZE, BY2PG, L1SIZE, 0);
if(m->mmul1 == nil)
panic("mmu1init: no memory for mmul1");
memset(m->mmul1, 0, L1SIZE+L1TOPSIZE);
mmuswitch(nil);
}
uintptr
paddr(void *va)
{
if((uintptr)va >= KZERO)
return (uintptr)va-KZERO;
panic("paddr: va=%#p pc=%#p", va, getcallerpc(&va));
return 0;
}
uintptr
cankaddr(uintptr pa)
{
if(pa < (uintptr)-KZERO)
return -KZERO - pa;
return 0;
}
void*
kaddr(uintptr pa)
{
if(pa < (uintptr)-KZERO)
return (void*)(pa + KZERO);
panic("kaddr: pa=%#p pc=%#p", pa, getcallerpc(&pa));
return nil;
}
void
kmapinval(void)
{
}
KMap*
kmap(Page *p)
{
return kaddr(p->pa);
}
void
kunmap(KMap*)
{
}
uintptr
mmukmap(uintptr va, uintptr pa, usize size)
{
uintptr a, pe, off, attr;
if(va == 0)
return 0;
attr = va & PTEMA(7);
va &= -PGLSZ(1);
off = pa % PGLSZ(1);
a = va + off;
pe = (pa + size + (PGLSZ(1)-1)) & -PGLSZ(1);
while(pa < pe){
((uintptr*)L1)[PTL1X(va, 1)] = pa | PTEVALID | PTEBLOCK | PTEWRITE | PTEAF
| PTEKERNEL | PTESH(SHARE_OUTER) | attr;
pa += PGLSZ(1);
va += PGLSZ(1);
}
flushtlb();
return a;
}
static uintptr*
mmuwalk(uintptr va, int level)
{
uintptr *table, pte;
Page *pg;
int i, x;
x = PTLX(va, PTLEVELS-1);
table = &m->mmul1[L1TABLEX(va, PTLEVELS-1)];
for(i = PTLEVELS-2; i >= level; i--){
pte = table[x];
if(pte & PTEVALID) {
if(pte & (0xFFFFULL<<48))
iprint("strange pte %#p va %#p\n", pte, va);
pte &= ~(0xFFFFULL<<48 | BY2PG-1);
table = KADDR(pte);
} else {
if(i < 2){
pg = up->mmufree;
if(pg == nil)
return nil;
up->mmufree = pg->next;
switch(i){
case 0:
pg->va = va & -PGLSZ(1);
if((pg->next = up->mmul1) == nil)
up->mmul1tail = pg;
up->mmul1 = pg;
break;
case 1:
pg->va = va & -PGLSZ(2);
if((pg->next = up->mmul2) == nil)
up->mmul2tail = pg;
up->mmul2 = pg;
break;
}
memset(KADDR(pg->pa), 0, BY2PG);
coherence();
table[x] = pg->pa | PTEVALID | PTETABLE;
table = KADDR(pg->pa);
} else {
table[x] = PADDR(&m->mmul1[L1TABLEX(va, 2)]) | PTEVALID | PTETABLE;
table = &m->mmul1[L1TABLEX(va, 2)];
}
}
x = PTLX(va, (uintptr)i);
}
return &table[x];
}
static Proc *asidlist[256];
static int
allocasid(Proc *p)
{
static Lock lk;
Proc *x;
int a;
lock(&lk);
a = p->asid;
if(a < 0)
a = -a;
if(a == 0)
a = p->pid;
for(;; a++){
a %= nelem(asidlist);
if(a == 0)
continue; // reserved
x = asidlist[a];
if(x == p || x == nil || (x->asid < 0 && x->mach == nil))
break;
}
p->asid = a;
asidlist[a] = p;
unlock(&lk);
return x != p;
}
static void
freeasid(Proc *p)
{
int a;
a = p->asid;
if(a < 0)
a = -a;
if(a > 0 && asidlist[a] == p)
asidlist[a] = nil;
p->asid = 0;
}
void
putasid(Proc *p)
{
/*
* Prevent the following scenario:
* pX sleeps on cpuA, leaving its page tables in mmul1
* pX wakes up on cpuB, and exits, freeing its page tables
* pY on cpuB allocates a freed page table page and overwrites with data
* cpuA takes an interrupt, and is now running with bad page tables
* In theory this shouldn't hurt because only user address space tables
* are affected, and mmuswitch will clear mmul1 before a user process is
* dispatched. But empirically it correlates with weird problems, eg
* resetting of the core clock at 0x4000001C which confuses local timers.
*/
if(conf.nmach > 1)
mmuswitch(nil);
if(p->asid > 0)
p->asid = -p->asid;
}
void
putmmu(uintptr va, uintptr pa, Page *pg)
{
uintptr *pte, old;
int s;
// iprint("cpu%d: putmmu va %#p asid %d proc %lud %s\n", m->machno, va, up->asid, up->pid, up->text);
s = splhi();
while((pte = mmuwalk(va, 0)) == nil){
spllo();
assert(up->mmufree == nil);
up->mmufree = newpage(0, nil, 0);
splhi();
}
old = *pte;
*pte = 0;
if((old & PTEVALID) != 0)
flushasidvall((uvlong)up->asid<<48 | va>>12);
else
flushasidva((uvlong)up->asid<<48 | va>>12);
*pte = pa | PTEPAGE | PTEUSER | PTENG | PTEAF | PTESH(SHARE_INNER);
if(pg->txtflush & (1UL<<m->machno)){
/* pio() sets PG_TXTFLUSH whenever a text pg has been written */
cachedwbinvse((void*)KADDR(pg->pa), BY2PG);
cacheiinvse((void*)va, BY2PG);
pg->txtflush &= ~(1UL<<m->machno);
}
splx(s);
}
static void
mmufree(Proc *p)
{
freeasid(p);
if(p->mmul1 == nil){
assert(p->mmul2 == nil);
return;
}
p->mmul1tail->next = p->mmufree;
p->mmufree = p->mmul1;
p->mmul1 = p->mmul1tail = nil;
if(PTLEVELS > 2){
p->mmul2tail->next = p->mmufree;
p->mmufree = p->mmul2;
p->mmul2 = p->mmul2tail = nil;
}
}
void
mmuswitch(Proc *p)
{
uintptr va;
Page *t;
for(va = UZERO; va < USTKTOP; va += PGLSZ(PTLEVELS-1))
m->mmul1[PTL1X(va, PTLEVELS-1)] = 0;
if(p == nil){
setttbr(PADDR(&m->mmul1[L1TABLEX(0, PTLEVELS-1)]));
return;
}
if(p->newtlb){
mmufree(p);
p->newtlb = 0;
}
if(PTLEVELS == 2){
for(t = p->mmul1; t != nil; t = t->next){
va = t->va;
m->mmul1[PTL1X(va, 1)] = t->pa | PTEVALID | PTETABLE;
}
} else {
for(t = p->mmul2; t != nil; t = t->next){
va = t->va;
m->mmul1[PTL1X(va, 2)] = t->pa | PTEVALID | PTETABLE;
if(PTLEVELS > 3)
m->mmul1[PTL1X(va, 3)] = PADDR(&m->mmul1[L1TABLEX(va, 2)]) |
PTEVALID | PTETABLE;
}
}
if(allocasid(p))
flushasid((uvlong)p->asid<<48);
// iprint("cpu%d: mmuswitch asid %d proc %lud %s\n", m->machno, p->asid, p->pid, p->text);
setttbr((uvlong)p->asid<<48 | PADDR(&m->mmul1[L1TABLEX(0, PTLEVELS-1)]));
}
void
mmurelease(Proc *p)
{
Page *t;
mmuswitch(nil);
mmufree(p);
if((t = p->mmufree) != nil){
do {
p->mmufree = t->next;
if(--t->ref != 0)
panic("mmurelease: bad page ref");
pagechainhead(t);
} while((t = p->mmufree) != nil);
pagechaindone();
}
}
void
flushmmu(void)
{
int x;
x = splhi();
up->newtlb = 1;
mmuswitch(up);
splx(x);
}
void
checkmmu(uintptr, uintptr)
{
}