diff options
Diffstat (limited to 'os/js/mmu.c')
| -rw-r--r-- | os/js/mmu.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/os/js/mmu.c b/os/js/mmu.c new file mode 100644 index 00000000..4283fa79 --- /dev/null +++ b/os/js/mmu.c @@ -0,0 +1,252 @@ +#include "u.h" +#include "../port/lib.h" +#include "mem.h" +#include "dat.h" +#include "fns.h" +#include "io.h" + +typedef struct Ctx Ctx; +/* + * software description of an MMU context + */ +struct Ctx +{ + Ctx *prev; /* less recently used */ + Ctx *next; /* more recently used */ + Proc *proc; /* process that owns this context */ + ushort index; /* which context this is */ +}; + +ulong *ioptes; /* IO MMU's table (shared by all processors) */ + +/* offset of x into the three page table levels in a context */ +#define AOFF(x) (((ulong)x)>>24) +#define BOFF(x) ((((ulong)x)>>18)&(64-1)) +#define COFF(x) ((((ulong)x)>>12)&(64-1)) +#define ISPTAB(x) ((((ulong)x)&3) == PTPVALID) +#define KPN(va) PPN(PADDR(va)) + +#define NIOPTE (DMASEGSIZE/BY2PG) + +/* + * allocate kernel page map and enter one mapping. Return + * address of the mapping. + */ +static ulong* +putkmmu(ulong virt, ulong phys, int level) +{ + ulong *a, *b, *c; + + + a = &PPT(m->contexts[0])[AOFF(virt)]; + if(level > 1) { + if(*a == 0){ + b = (ulong*)xspanalloc(64*sizeof(ulong), + 64*sizeof(ulong), 0); + *a = KPN(b) | PTPVALID; + } else { + if(!ISPTAB(*a)) + panic("putkmmu virt=%lux *a=%lux", virt, *a); + b = PPT(*a); + } + b = &b[BOFF(virt)]; + if(level > 2) { + if(*b == 0){ + c = (ulong*)xspanalloc(64*sizeof(ulong), + 64*sizeof(ulong), 0); + *b = KPN(c) | PTPVALID; + } else { + if(!ISPTAB(*b)) + panic("putkmmu virt=%lux *b=%lux", + virt, *b); + c = PPT(*b); + } + c = &c[COFF(virt)]; + *c = phys; + return c; + } else { + *b = phys; + return b; + } + } else { + *a = phys; + return a; + } +} + +void +mmuinit(void) +{ + int i, n; + ulong *a; + + m->contexts = (ulong*)xspanalloc(conf.ncontext*sizeof(ulong), + conf.ncontext*sizeof(ulong), + 0); + + /* + * context 0 will have the prototype level 1 entries + */ + a = (ulong*)xspanalloc(256*sizeof(ulong), 256*sizeof(ulong), 0); + + m->contexts[0] = KPN(a) | PTPVALID; + + /* + * map all memory to KZERO + */ + n = 128*MB/BY2PG; + + /* pages to first segment boundary */ + for(i=0; i<(256*1024/BY2PG); i++) + putkmmu(KZERO|(i*BY2PG), + PPN(i*BY2PG)|PTEKERNEL|PTEWRITE|PTEVALID|PTECACHE, 3); + + /* segments to first 16Mb boundary */ + for(; i<(16*MB)/BY2PG; i += 64) + putkmmu(KZERO|(i*BY2PG), + PPN(i*BY2PG)|PTEKERNEL|PTEWRITE|PTEVALID|PTECACHE, 2); + + /* 16 Mbyte regions to end */ + for(; i<n; i += 64*64) + putkmmu(KZERO|(i*BY2PG), + PPN(i*BY2PG)|PTEKERNEL|PTEWRITE|PTEVALID|PTECACHE, 1); + + /* + * allocate page table pages for IO mapping + */ + n = IOSEGSIZE/BY2PG; + for(i=0; i<n; i++) + putkmmu(IOSEGBASE+(i*BY2PG), 0, 3); + + /* + * load kernel context + */ + + putrmmu(CTPR, PADDR(m->contexts)>>4); + putrmmu(CXR, 0); + flushtlb(); + + ioptes = (ulong*)xspanalloc(NIOPTE*sizeof(ulong), DMASEGSIZE/1024, 0); + putphys(IBAR, PADDR(ioptes)>>4); + putphys(IOCR, (DMARANGE<<2)|1); /* IO MMU enable */ +} + + +void +flushicache(void) +{ + int i; + ulong addr = 0; + + for(i=0;i<512;i++) { + flushiline(addr); + addr += 1<<5; + } +} + +void +flushdcache(void) +{ + int i; + ulong addr = 0; + + for(i=0;i<512;i++) { + flushdline(addr); + addr += 1<<5; + } +} + +int +segflush(void *p, ulong l) +{ + USED(p,l); + flushicache(); + return 0; +} + +void +cacheinit(void) +{ + flushdcache(); + flushicache(); + setpcr(getpcr()|ENABCACHE); +} + +typedef struct Mregion Mregion; +struct Mregion +{ + ulong addr; + long size; +}; + +struct +{ + Mregion io; + Mregion dma; + Lock; +}kmapalloc = { + {IOSEGBASE, IOSEGSIZE}, + {DMASEGBASE, DMASEGSIZE}, +}; + +void +kmapinit(void) +{ +} + +KMap* +kmappa(ulong pa, ulong flag) +{ + ulong k; + + lock(&kmapalloc); + k = kmapalloc.io.addr; + kmapalloc.io.addr += BY2PG; + if((kmapalloc.io.size -= BY2PG) < 0) + panic("kmappa"); + putkmmu(k, PPN(pa)|PTEKERNEL|PTEWRITE|PTEVALID|flag, 3); + flushtlbpage(k); + unlock(&kmapalloc); + return (KMap*)k; +} + +ulong +kmapdma(ulong pa, ulong n) +{ + ulong va0, va; + int i, j; + + + lock(&kmapalloc); + i = (n+(BY2PG-1))/BY2PG; + va0 = kmapalloc.dma.addr; + kmapalloc.dma.addr += i*BY2PG; + if((kmapalloc.dma.size -= i*BY2PG) <= 0) + panic("kmapdma"); + va = va0; + for(j=0; j<i; j++) { + putkmmu(va, PPN(pa)|PTEKERNEL|PTEVALID|PTEWRITE, 3); + flushtlbpage(va); + ioptes[(va>>PGSHIFT)&(NIOPTE-1)] = PPN(pa)|IOPTEVALID|IOPTEWRITE; + va += BY2PG; + pa += BY2PG; + } + unlock(&kmapalloc); + return va0; +} + +/* + * map the frame buffer + */ +ulong +kmapsbus(int slot) +{ + int i, n; + + lock(&kmapalloc); + n = FBSEGSIZE/BY2PG; + for(i=0; i<n; i += 64*64) + putkmmu(FBSEGBASE+(i*BY2PG), PPN(SBUS(slot)+(i*BY2PG))|PTEKERNEL|PTEWRITE|PTEVALID, 1); + unlock(&kmapalloc); + return FBSEGBASE; +} |