1994/0913/port/devsd.c (diff list | history)

port/devsd.c on 1994/0913
1994/0913		/* * SCSI disc driver */ #include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "devtab.h" enum { LogNpart = 3, Npart = 1<<LogNpart, Ndisk = 32, Nlun = 8, }; #define DRIVE(qid) ((qid).path>>LogNpart) #define PART(qid) ((qid).path&(Npart-1)) typedef struct Part Part; typedef struct Disk Disk; struct Part { ulong beg; ulong end; char name[NAMELEN]; }; struct Disk { QLock; Target* t; uchar lun; char id[NAMELEN]; char vol[NAMELEN]; uchar* inquire; ulong size; ulong bsize; int npart; Part table[Npart]; }; int ndisk; Disk disk[Ndisk]; static void sdrdpart(Disk*); static long sdio(Chan*, int, char*, ulong, ulong); static int sdgen(Chan *c, Dirtab *tab, long ntab, long s, Dir *dirp) { Qid qid; Disk *d; Part *p; int unit; char name[2*NAMELEN]; USED(tab, ntab); d = disk; while(s >= d->npart) { s -= d->npart; d++; } unit = d - disk; if(unit > ndisk) return -1; p = d->table+s; sprint(name, "%s%s", d->vol, p->name); name[NAMELEN-1] = '\0'; qid = (Qid){(unit<<LogNpart)+s, 0}; devdir(c, qid, name, (p->end - p->beg) * d->bsize, eve, 0666, dirp); return 1; } void sdreset(void) { } void sdinit(void) { Disk *d; ulong s, b; int dev, i; dev = 0; for(;;) { d = &disk[ndisk]; dev = scsiinv(dev, 0, &d->t, &d->inquire, d->id); if(dev < 0) break; if(scsistart(d->t, 0, 1) != STok) continue; /* Search for other lun's */ for(i = 0; i < Nlun; i++) { d->lun = i; scsireqsense(d->t, d->lun, 1); /* NCR Raid only seems to answer second capacity * command if lun != 0 */ if(scsicap(d->t, d->lun, &s, &b) != STok) { scsireqsense(d->t, 0, 1); continue; } scsireqsense(d->t, 0, 1); s = 0; b = 0; if(scsicap(d->t, d->lun, &s, &b) != STok) { scsireqsense(d->t, 0, 1); continue; } if(scsireqsense(d->t, d->lun, 1) != STok) continue; if(s == 0 || b == 0) continue; d->size = s; d->bsize = b; sprint(d->vol, "sd%d", ndisk); if(++ndisk >= Ndisk) break; d++; d->t = d[-1].t; d->inquire = d[-1].inquire; strcpy(d->id, d[-1].id); } if(ndisk >= Ndisk) { print("devsd: configure more disks\n"); break; } } } Chan* sdattach(char *spec) { int i; for(i = 0; i < ndisk; i++) sdrdpart(&disk[i]); return devattach('w', spec); } Chan * sdclone(Chan *c, Chan *nc) { return devclone(c, nc); } int sdwalk(Chan *c, char *name) { return devwalk(c, name, 0, 0, sdgen); } void sdstat(Chan *c, char *db) { devstat(c, db, 0, 0, sdgen); } Chan * sdopen(Chan *c, int omode) { return devopen(c, omode, 0, 0, sdgen); } void sdcreate(Chan *c, char *name, int omode, ulong perm) { USED(c, name, omode, perm); error(Eperm); } void sdremove(Chan *c) { USED(c); error(Eperm); } void sdwstat(Chan *c, char *dp) { USED(c, dp); error(Eperm); } void sdclose(Chan *c) { Disk *d; Part *p; if(c->mode != OWRITE && c->mode != ORDWR) return; d = &disk[DRIVE(c->qid)]; p = &d->table[PART(c->qid)]; if(strcmp(p->name, "partition")) return; sdrdpart(d); } long sdread(Chan *c, void *a, long n, ulong offset) { if(c->qid.path == CHDIR) return devdirread(c, a, n, 0, 0, sdgen); return sdio(c, 0, a, n, offset); } long sdwrite(Chan *c, char *a, long n, ulong offset) { return sdio(c, 1, a, n, offset); } static void sdrdpart(Disk *d) { Part *p; int n, i; char *b, *line[Npart+2], *field[3]; static char MAGIC[] = "plan9 partitions"; b = scsialloc(d->bsize); if(b == 0) error(Enomem); qlock(d); p = d->table; strcpy(p->name, "disk"); p->beg = 0; p->end = d->size + 1; p++; strcpy(p->name, "partition"); p->beg = d->table[0].end - 1; p->end = d->table[0].end; p++; d->npart = 2; scsibio(d->t, d->lun, SCSIread, b, 1, d->bsize, d->table[0].end-1); b[d->bsize-1] = '\0'; /* * parse partition table. */ n = getfields(b, line, Npart+2, '\n'); if(n > 0 && strncmp(line[0], MAGIC, sizeof(MAGIC)-1) == 0) { for(i = 1; i < n; i++) { switch(getfields(line[i], field, 3, ' ')) { case 2: if(strcmp(field[0], "unit") == 0) strncpy(d->vol, field[1], NAMELEN); break; case 3: strncpy(p->name, field[0], NAMELEN); p->beg = strtoul(field[1], 0, 0); p->end = strtoul(field[2], 0, 0); if(p->beg > p->end || p->beg >= d->table[0].end) break; p++; } } } d->npart = p - d->table; scsifree(b); qunlock(d); } static long sdio(Chan *c, int write, char *a, ulong len, ulong offset) { Disk *d; Part *p; uchar *b; ulong block, n, max, x; d = &disk[DRIVE(c->qid)]; p = &d->table[PART(c->qid)]; block = (offset / d->bsize) + p->beg; n = (offset + len + d->bsize - 1) / d->bsize + p->beg - block; max = SCSImaxxfer / d->bsize; if(n > max) n = max; if(block + n > p->end) n = p->end - block; if(block >= p->end || n == 0) return 0; b = scsialloc(n*d->bsize); if(b == 0) error(Enomem); if(waserror()) { scsifree(b); nexterror(); } offset %= d->bsize; if(write) { if(offset || len % d->bsize) { x = scsibio(d->t, d->lun, SCSIread, b, n, d->bsize, block); if(x < n * d->bsize) { n = x / d->bsize; x = n * d->bsize - offset; if(len > x) len = x; } } memmove(b + offset, a, len); x = scsibio(d->t, d->lun, SCSIwrite, b, n, d->bsize, block); if(x < offset) len = 0; else if(len > x - offset) len = x - offset; } else { x = scsibio(d->t, d->lun, SCSIread, b, n, d->bsize, block); if(x < offset) len = 0; else if(len > x - offset) len = x - offset; memmove(a, b+offset, len); } poperror(); scsifree(b); return len; }