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pc64: simplify mmuwalk by factoring out mmu page table creation into separate function

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This commit is contained in:
cinap_lenrek 2014-02-15 16:43:55 +01:00
parent c6f6396faa
commit 25189924db
1 changed files with 50 additions and 43 deletions
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93
sys/src/9/pc64/mmu.c
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@ -205,12 +205,58 @@ mmualloc(void)
return p;
}
static uintptr*
mmucreate(uintptr *table, uintptr va, int level, int index)
{
uintptr *page, flags;
MMU *p;
flags = PTEWRITE|PTEVALID;
if(va < VMAP){
assert(up != nil);
assert((va < TSTKTOP) || (va >= KMAP && va < KMAP+KMAPSIZE));
p = mmualloc();
p->index = level;
p->level = index;
if(va < TSTKTOP){
flags |= PTEUSER;
if(level == PML4E){
if((p->next = up->mmuhead) == nil)
up->mmutail = p;
up->mmuhead = p;
m->mmumap[index/MAPBITS] |= 1ull<<(index%MAPBITS);
} else {
up->mmutail->next = p;
up->mmutail = p;
}
up->mmucount++;
} else {
if(level == PML4E){
up->kmaptail = p;
up->kmaphead = p;
} else {
up->kmaptail->next = p;
up->kmaptail = p;
}
up->kmapcount++;
}
page = p->page;
} else if(didmmuinit) {
page = mallocalign(PTSZ, BY2PG, 0, 0);
} else {
page = rampage();
}
memset(page, 0, PTSZ);
table[index] = PADDR(page) | flags;
return page;
}
uintptr*
mmuwalk(uintptr* table, uintptr va, int level, int create)
{
uintptr pte, *page;
uintptr pte;
int i, x;
MMU *p;
x = PTLX(va, 3);
for(i = 2; i >= level; i--){
@ -219,49 +265,10 @@ mmuwalk(uintptr* table, uintptr va, int level, int create)
if(pte & PTESIZE)
return 0;
table = KADDR(PPN(pte));
} else {
} else {
if(!create)
return 0;
pte = PTEWRITE|PTEVALID;
if(va < VMAP){
if(va < TSTKTOP){
pte |= PTEUSER;
p = mmualloc();
p->index = x;
p->level = i;
if(i == PML4E){
if((p->next = up->mmuhead) == nil)
up->mmutail = p;
up->mmuhead = p;
m->mmumap[p->index/MAPBITS] |= 1ull<<(p->index%MAPBITS);
} else {
up->mmutail->next = p;
up->mmutail = p;
}
up->mmucount++;
} else if(va >= KMAP && va < (KMAP+KMAPSIZE)) {
p = mmualloc();
p->index = x;
p->level = i;
if(i == PML4E){
up->kmaptail = p;
up->kmaphead = p;
} else {
up->kmaptail->next = p;
up->kmaptail = p;
}
up->kmapcount++;
} else
return 0;
page = p->page;
} else if(didmmuinit) {
page = mallocalign(PTSZ, BY2PG, 0, 0);
} else
page = rampage();
memset(page, 0, PTSZ);
table[x] = PADDR(page) | pte;
table = page;
table = mmucreate(table, va, i, x);
}
x = PTLX(va, i);
}