ref: d376fac66cbd5efbe2f9f61a1e8b31af03a84a92
dir: /sys/src/9/port/sdram.c/
/* * ramdisk driver */ #include "u.h" #include "../port/lib.h" #include "../port/error.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #include "../port/sd.h" typedef struct Ramdisk Ramdisk; struct Ramdisk { Segment *seg; Segio sio; ulong nb; ulong ss; ulong off; char buf[16]; Physseg; }; static Ramdisk rds[4]; extern SDifc sdramifc; static uvlong ramdiskalloc(uvlong base, ulong pages) { uvlong limit, mbase, mlimit; int i, j; if(pages == 0) return 0; if(base == 0){ /* allocate pages from the end of memoy banks */ for(i=nelem(conf.mem)-1; i>=0; i--) if(conf.mem[i].npage >= pages){ conf.mem[i].npage -= pages; return (uvlong)conf.mem[i].base + (uvlong)conf.mem[i].npage*BY2PG; } return 0; } /* exclude pages from memory banks */ limit = base + (uvlong)pages*BY2PG; for(i=0; i<nelem(conf.mem); i++){ mbase = conf.mem[i].base; mlimit = mbase + (uvlong)conf.mem[i].npage*BY2PG; if(base >= mlimit || limit <= mbase) continue; if(base >= mbase) conf.mem[i].npage = (base - mbase) / BY2PG; if(limit < mlimit){ for(j=0; j<nelem(conf.mem); j++){ if(conf.mem[j].npage == 0){ conf.mem[j].base = limit; conf.mem[j].npage = (mlimit - limit) / BY2PG; break; } } } } return base; } static void ramdiskinit0(Ramdisk *rd, uvlong base, uvlong size, ulong ss) { ulong nb, off; if(ss == 0) ss = 512; nb = size / ss; off = base & (BY2PG-1); size = (uvlong)nb*ss; size += off; size += BY2PG-1; size &= ~(BY2PG-1); base &= ~(BY2PG-1); if(size == 0 || size != (uintptr)size){ print("%s: invalid parameters\n", rd->name); return; } base = ramdiskalloc(base, size/BY2PG); if(base == 0){ print("%s: allocation failed\n", rd->name); return; } rd->nb = nb; rd->ss = ss; rd->off = off; rd->pa = base; rd->size = size; rd->attr = SG_PHYSICAL | SG_CACHED | SG_NOEXEC; } static vlong getsizenum(char **p) { vlong v = strtoll(*p, p, 0); switch(**p){ case 'T': case 't': v <<= 10; case 'G': case 'g': v <<= 10; case 'M': case 'm': v <<= 10; case 'K': case 'k': v <<= 10; (*p)++; } return v; } void ramdiskinit(void) { Ramdisk *rd; uvlong a[3]; char *p; int subno, n; for(subno=0; subno<nelem(rds); subno++){ rd = &rds[subno]; if(rd->nb != 0) continue; snprint(rd->name = rd->buf, sizeof(rd->buf), "ramdisk%d", subno); if((p = getconf(rd->name)) == nil) continue; for(n = 0; n < nelem(a); n++){ while(*p == ' ' || *p == '\t') p++; if(*p == 0) break; a[n] = getsizenum(&p); switch(*p){ case '-': case '+': a[n] += getsizenum(&p); break; } } switch(n){ case 1: /* ramdiskX=size */ ramdiskinit0(rd, 0, a[0], 0); break; case 2: /* ramdiskX=size ss */ ramdiskinit0(rd, 0, a[0], (ulong)a[1]); break; case 3: /* ramdiskX=base size ss */ ramdiskinit0(rd, a[0], a[1], (ulong)a[2]); break; } } } static SDev* rampnp(void) { SDev *sdev; sdev = xalloc(sizeof(SDev)); if(sdev == nil) return nil; sdev->idno = 'Z'; sdev->ifc = &sdramifc; sdev->nunit = nelem(rds); return sdev; } static int ramverify(SDunit *unit) { Ramdisk *rd = &rds[unit->subno]; if(rd->nb == 0) return 0; unit->inquiry[0] = 0; unit->inquiry[1] = 0; unit->inquiry[4] = sizeof unit->inquiry - 4; strcpy((char*)unit->inquiry+8, rd->name); return 1; } static int ramonline(SDunit *unit) { Ramdisk *rd = &rds[unit->subno]; if(unit->sectors != 0) return 1; rd->seg = newseg(rd->attr, UTZERO, rd->size/BY2PG); if(rd->seg == nil) return 0; rd->seg->pseg = rd; unit->sectors = rd->nb; unit->secsize = rd->ss; return 2; } static int ramrctl(SDunit *unit, char *p, int l) { Ramdisk *rd = &rds[unit->subno]; return snprint(p, l, "geometry %llud %ld\nalignment %lud %lud\n", unit->sectors, unit->secsize, (ulong)BY2PG, rd->off / unit->secsize); } static long rambio(SDunit *unit, int, int write, void *data, long nb, uvlong bno) { Ramdisk *rd = &rds[unit->subno]; long secsize = unit->secsize; return segio(&rd->sio, rd->seg, data, nb*secsize, bno*secsize + rd->off, !write); } static int ramrio(SDreq *r) { int i, rw, count; uvlong lba; if((i = sdfakescsi(r)) != SDnostatus) return r->status = i; if((i = sdfakescsirw(r, &lba, &count, &rw)) != SDnostatus) return i; r->rlen = rambio(r->unit, r->lun, rw == SDwrite, r->data, count, lba); return r->status = SDok; } SDifc sdramifc = { .name = "ram", .pnp = rampnp, .verify = ramverify, .online = ramonline, .rctl = ramrctl, .bio = rambio, .rio = ramrio, };