1 /* 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 * 9 * $FreeBSD$ 10 * 11 */ 12 13 #include <sys/param.h> 14 #include <sys/systm.h> 15 #include <sys/buf.h> 16 #include <sys/conf.h> 17 #include <sys/devicestat.h> 18 #include <sys/disk.h> 19 #include <sys/kernel.h> 20 #include <sys/malloc.h> 21 #include <sys/sysctl.h> 22 23 #ifndef MDNSECT 24 #define MDNSECT (10000 * 2) 25 #endif 26 27 MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk"); 28 MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors"); 29 30 static int md_debug = 0; 31 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, ""); 32 33 #define CDEV_MAJOR 95 34 #define BDEV_MAJOR 22 35 36 static d_strategy_t mdstrategy; 37 static d_open_t mdopen; 38 static d_ioctl_t mdioctl; 39 40 static struct cdevsw md_cdevsw = { 41 /* open */ mdopen, 42 /* close */ nullclose, 43 /* read */ physread, 44 /* write */ physwrite, 45 /* ioctl */ mdioctl, 46 /* poll */ nopoll, 47 /* mmap */ nommap, 48 /* strategy */ mdstrategy, 49 /* name */ "md", 50 /* maj */ CDEV_MAJOR, 51 /* dump */ nodump, 52 /* psize */ nopsize, 53 /* flags */ D_DISK | D_CANFREE, 54 /* bmaj */ BDEV_MAJOR 55 }; 56 static struct cdevsw mddisk_cdevsw; 57 58 struct md_s { 59 int unit; 60 struct devstat stats; 61 struct buf_queue_head buf_queue; 62 struct disk disk; 63 dev_t dev; 64 unsigned nsect; 65 unsigned nsecp; 66 u_char **secp; 67 68 int busy; 69 }; 70 71 static int mdunits; 72 73 static int 74 mdopen(dev_t dev, int flag, int fmt, struct proc *p) 75 { 76 struct md_s *sc; 77 struct disklabel *dl; 78 79 if (md_debug) 80 printf("mdopen(%s %x %x %p)\n", 81 devtoname(dev), flag, fmt, p); 82 83 sc = dev->si_drv1; 84 85 dl = &sc->disk.d_label; 86 bzero(dl, sizeof(*dl)); 87 dl->d_secsize = DEV_BSIZE; 88 dl->d_nsectors = 1024; 89 dl->d_ntracks = 1; 90 dl->d_secpercyl = dl->d_nsectors + dl->d_ntracks; 91 dl->d_secperunit = sc->nsect; 92 dl->d_ncylinders = dl->d_secperunit / dl->d_secpercyl; 93 return (0); 94 } 95 96 static int 97 mdioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct proc *p) 98 { 99 100 if (md_debug) 101 printf("mdioctl(%s %lx %p %x %p)\n", 102 devtoname(dev), cmd, addr, flags, p); 103 104 return (ENOIOCTL); 105 } 106 107 static void 108 mdstrategy(struct buf *bp) 109 { 110 int s, i; 111 struct md_s *sc; 112 devstat_trans_flags dop; 113 u_char *secp, **secpp, *dst; 114 unsigned secno, nsec, secval, uc; 115 116 if (md_debug > 1) 117 printf("mdstrategy(%p) %s %lx, %d, %ld, %p)\n", 118 bp, devtoname(bp->b_dev), bp->b_flags, bp->b_blkno, 119 bp->b_bcount / DEV_BSIZE, bp->b_data); 120 121 sc = bp->b_dev->si_drv1; 122 123 s = splbio(); 124 125 bufqdisksort(&sc->buf_queue, bp); 126 127 if (sc->busy) { 128 splx(s); 129 return; 130 } 131 132 sc->busy++; 133 134 while (1) { 135 bp = bufq_first(&sc->buf_queue); 136 if (bp) 137 bufq_remove(&sc->buf_queue, bp); 138 splx(s); 139 if (!bp) 140 break; 141 142 devstat_start_transaction(&sc->stats); 143 144 if (bp->b_flags & B_FREEBUF) 145 dop = DEVSTAT_NO_DATA; 146 else if (bp->b_flags & B_READ) 147 dop = DEVSTAT_READ; 148 else 149 dop = DEVSTAT_WRITE; 150 151 nsec = bp->b_bcount / DEV_BSIZE; 152 secno = bp->b_pblkno; 153 dst = bp->b_data; 154 while (nsec--) { 155 156 if (secno < sc->nsecp) { 157 secpp = &sc->secp[secno]; 158 if ((u_int)*secpp > 255) { 159 secp = *secpp; 160 secval = 0; 161 } else { 162 secp = 0; 163 secval = (u_int) *secpp; 164 } 165 } else { 166 secpp = 0; 167 secp = 0; 168 secval = 0; 169 } 170 if (md_debug > 2) 171 printf("%lx %p %p %d\n", bp->b_flags, secpp, secp, secval); 172 173 if (bp->b_flags & B_FREEBUF) { 174 if (secpp) { 175 if (secp) 176 FREE(secp, M_MDSECT); 177 *secpp = 0; 178 } 179 } else if (bp->b_flags & B_READ) { 180 if (secp) { 181 bcopy(secp, dst, DEV_BSIZE); 182 } else if (secval) { 183 for (i = 0; i < DEV_BSIZE; i++) 184 dst[i] = secval; 185 } else { 186 bzero(dst, DEV_BSIZE); 187 } 188 } else { 189 uc = dst[0]; 190 for (i = 1; i < DEV_BSIZE; i++) 191 if (dst[i] != uc) 192 break; 193 if (i == DEV_BSIZE && !uc) { 194 if (secp) 195 FREE(secp, M_MDSECT); 196 if (secpp) 197 *secpp = (u_char *)uc; 198 } else { 199 if (!secpp) { 200 MALLOC(secpp, u_char **, (secno + nsec + 1) * sizeof(u_char *), M_MD, M_WAITOK); 201 bzero(secpp, (secno + nsec + 1) * sizeof(u_char *)); 202 bcopy(sc->secp, secpp, sc->nsecp * sizeof(u_char *)); 203 FREE(sc->secp, M_MD); 204 sc->secp = secpp; 205 sc->nsecp = secno + nsec + 1; 206 secpp = &sc->secp[secno]; 207 } 208 if (i == DEV_BSIZE) { 209 if (secp) 210 FREE(secp, M_MDSECT); 211 *secpp = (u_char *)uc; 212 } else { 213 if (!secp) 214 MALLOC(secp, u_char *, DEV_BSIZE, M_MDSECT, M_WAITOK); 215 bcopy(dst, secp, DEV_BSIZE); 216 217 *secpp = secp; 218 } 219 } 220 } 221 secno++; 222 dst += DEV_BSIZE; 223 } 224 225 bp->b_resid = 0; 226 devstat_end_transaction_buf(&sc->stats, bp); 227 biodone(bp); 228 s = splbio(); 229 } 230 sc->busy = 0; 231 return; 232 } 233 234 static dev_t 235 mdcreate(void) 236 { 237 struct md_s *sc; 238 239 MALLOC(sc, struct md_s *,sizeof(*sc), M_MD, M_WAITOK); 240 bzero(sc, sizeof(*sc)); 241 sc->unit = mdunits++; 242 243 bufq_init(&sc->buf_queue); 244 245 devstat_add_entry(&sc->stats, "md", sc->unit, DEV_BSIZE, 246 DEVSTAT_NO_ORDERED_TAGS, 247 DEVSTAT_TYPE_DIRECT | DEVSTAT_TYPE_IF_OTHER, 0x190); 248 249 sc->dev = disk_create(sc->unit, &sc->disk, 0, 250 &md_cdevsw, &mddisk_cdevsw); 251 252 sc->dev->si_drv1 = sc; 253 sc->nsect = MDNSECT; /* for now */ 254 MALLOC(sc->secp, u_char **, sizeof(u_char *), M_MD, M_WAITOK); 255 bzero(sc->secp, sizeof(u_char *)); 256 sc->nsecp = 1; 257 258 return (0); 259 } 260 261 static void 262 md_drvinit(void *unused) 263 { 264 265 mdcreate(); 266 } 267 268 SYSINIT(ptcdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR, md_drvinit,NULL) 269 270