ref: 86e0099835f99de6ccc3bee33a297387993aa037
dir: /sys/src/boot/alphapc/mmu.c/
#include "u.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "lib.h" static int debug; static uvlong by2pg; /* hwrpb->by2pg */ static uvlong pte2pg; /* by2pg/8 */ static uvlong pgmask; /* by2pg-1 */ static uvlong ptemask; /* pte2pg-1 */ static uvlong pgshift; /* log2(by2pg) */ static uvlong pteshift; /* log2(pte2pg) = pgshift - 3 */ #define L1(va) (((uvlong)(va)>>3*pteshift+3) & (pte2pg-1)) #define L2(va) (((uvlong)(va)>>2*pteshift+3) & (pte2pg-1)) #define L3(va) (((uvlong)(va)>>pgshift) & (pte2pg-1)) #define OFF(va) (((uvlong)(va)) & (by2pg-1)) #define V1(l1) (((vlong)l1<<(64-pteshift)) >> 64-(3*pteshift+3)) #define V2(l2) (((uvlong)l2<<(64-pteshift)) >> 64-(2*pteshift+3)) #define V3(l3) (((uvlong)l3<<(64-pteshift)) >> 64-pgshift) #define VA(l1, l2, l3, off) (V1(l1) | V2(l2) | V3(l3) | (off)) static int log2(uvlong x) { int i; if ((x & (x-1)) == 0) for (i = 0; i < 64; i++) if (x & (1<<i)) return i; panic("log2: %llux", x); return -1; } void mmuinit(void) { int i; uvlong npage, nlvl2, nlvl3; uvlong l1p, l2p, lvl2, lvl3; extern ulong _main[], edata[]; /* map entire physical memory at KZERO */ by2pg = hwrpb->by2pg; pte2pg = (by2pg >> 3); pgmask = by2pg-1; ptemask = pte2pg-1; pgshift = log2(by2pg); pteshift = pgshift-3; l1p = (1LL<<3*pteshift+3)|(1LL<<2*pteshift+3)|(1LL<<pgshift); if (rdv(l1p+8*(pte2pg-1)) != 0 || rdv(l1p+8*(pte2pg-2)) != 0) panic("KZERO lvl1 already mapped"); npage = (conf.maxphys+pgmask)>>pgshift; nlvl3 = (npage+ptemask)>>pteshift; nlvl2 = (nlvl3+ptemask)>>pteshift; if (nlvl2 > 1) panic("meminit: nlvl2"); /* cannot happen, due to virtual space limitation */ if (debug) print("nlvl1 %llud nlvl2 %llud nlvl3 %llud npage %llud\n", 1LL, nlvl2, nlvl3, npage); lvl2 = allocate(nlvl2+nlvl3); lvl3 = lvl2 + nlvl2*by2pg; wrv(l1p+8*(pte2pg-2), rdv(l1p+8)|PTEASM); wrv(l1p+8*(pte2pg-1), (lvl2<<(32-pgshift)) | PTEKVALID | PTEASM); l2p = (1LL<<3*pteshift+3)|(1LL<<2*pteshift+3)|((vlong)KZERO >> 2*pteshift)&((1LL<<2*pteshift+3)-1); for (i = 0; i < nlvl3; i++) stqp(lvl2+(l2p&(by2pg-1))+8*i, ((lvl3+i*by2pg)<<(32-pgshift)) | PTEKVALID | PTEASM); for (i = 0; i < npage; i++) stqp(lvl3+8*i, ((uvlong)i<<32) | PTEKVALID | PTEASM); tlbflush(); if (debug) print("\n"); } uvlong paddr(uvlong va) { uvlong ptbr, x, pte; ptbr = getptbr(); pte = ldqp((ptbr<<pgshift)+8*L1(va)); if ((pte&PTEKVALID) != PTEKVALID) return 0; x = ((pte>>32)<<pgshift); pte = ldqp(x+8*L2(va)); if ((pte&PTEKVALID) != PTEKVALID) return 0; x = ((pte>>32)<<pgshift); pte = ldqp(x+8*L3(va)); if ((pte&PTEKVALID) != PTEKVALID) return 0; x = ((pte>>32)<<pgshift); return x; } uvlong pground(uvlong x) { return (x+pgmask) & ~pgmask; }