1990/0709/gnot/mmu.c (diff list | history)

gnot/mmu.c on 1990/03091
1990/03091		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h"
1990/06021		struct { Lock; int init; KMap *free; KMap arena[4*1024*1024/BY2PG]; /* kernel mmu maps up to 4MB */ }kmapalloc;
1990/03091		/* * Called splhi, not in Running state */ void mapstack(Proc *p) { ulong tlbvirt, tlbphys; if(p->upage->va != (USERADDR|(p->pid&0xFFFF))) panic("mapstack %d 0x%lux 0x%lux", p->pid, p->upage->pa, p->upage->va); tlbvirt = USERADDR; tlbphys = PPN(p->upage->pa) | PTEVALID | PTEKERNEL; putkmmu(tlbvirt, tlbphys); flushmmu(); u = (User*)USERADDR; } void putkmmu(ulong tlbvirt, ulong tlbphys) { if(!(tlbvirt&KZERO)) panic("putkmmu"); tlbvirt &= ~KZERO; KMAP[(tlbvirt&0x003FE000L)>>2] = tlbphys; } void putmmu(ulong tlbvirt, ulong tlbphys) { if(tlbvirt&KZERO) panic("putmmu"); tlbphys |= VTAG(tlbvirt)<<24; UMAP[(tlbvirt&0x003FE000L)>>2] = tlbphys; } void flushmmu(void) { flushcpucache(); *PARAM &= ~TLBFLUSH_; *PARAM |= TLBFLUSH_;
1990/06021		} void kmapinit(void) { KMap *k; int i, e; if(kmapalloc.init == 0){ k = &kmapalloc.arena[0];
1990/0709		k->va = KZERO|(4*1024*1024-256*1024-BY2PG);
1990/06021		k->next = 0; kmapalloc.free = k; kmapalloc.init = 1; return; } e = (4*1024*1024 - 256*1024)/BY2PG; /* screen lives at top 256K */ i = (((ulong)ialloc(0, 0))&~KZERO)/BY2PG;
1990/0709		print("%lud free map registers\n", e-i);
1990/06021		kmapalloc.free = 0; for(k=&kmapalloc.arena[i]; i<e; i++,k++){ k->va = i*BY2PG|KZERO; kunmap(k); } } KMap* kmap(Page *pg) { KMap *k; lock(&kmapalloc); k = kmapalloc.free;
1990/0709		if(k == 0){ dumpstack();
1990/06021		panic("kmap");
1990/0709		}
1990/06021		kmapalloc.free = k->next; unlock(&kmapalloc); k->pa = pg->pa; putkmmu(k->va, PPN(k->pa) | PTEVALID | PTEKERNEL); return k; } void kunmap(KMap *k) { k->pa = 0; lock(&kmapalloc); k->next = kmapalloc.free; kmapalloc.free = k; putkmmu(k->va, INVALIDPTE); unlock(&kmapalloc);
1990/03091		}