drivers/block/sunvdc.c

   1 /* sunvdc.c: Sun LDOM Virtual Disk Client.
   2  *
   3  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/kernel.h>
   8 #include <linux/types.h>
   9 #include <linux/blkdev.h>
  10 #include <linux/hdreg.h>
  11 #include <linux/genhd.h>
  12 #include <linux/cdrom.h>
  13 #include <linux/slab.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/completion.h>
  16 #include <linux/delay.h>
  17 #include <linux/init.h>
  18 #include <linux/list.h>
  19 #include <linux/scatterlist.h>
  20
  21 #include <asm/vio.h>
  22 #include <asm/ldc.h>
  23
  24 #define DRV_MODULE_NAME         "sunvdc"
  25 #define PFX DRV_MODULE_NAME     ": "
  26 #define DRV_MODULE_VERSION      "1.1"
  27 #define DRV_MODULE_RELDATE      "February 13, 2013"
  28
  29 static char version[] =
  30         DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
  31 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
  32 MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
  33 MODULE_LICENSE("GPL");
  34 MODULE_VERSION(DRV_MODULE_VERSION);
  35
  36 #define VDC_TX_RING_SIZE        512
  37
  38 #define WAITING_FOR_LINK_UP     0x01
  39 #define WAITING_FOR_TX_SPACE    0x02
  40 #define WAITING_FOR_GEN_CMD     0x04
  41 #define WAITING_FOR_ANY         -1
  42
  43 struct vdc_req_entry {
  44         struct request          *req;
  45 };
  46
  47 struct vdc_port {
  48         struct vio_driver_state vio;
  49
  50         struct gendisk          *disk;
  51
  52         struct vdc_completion   *cmp;
  53
  54         u64                     req_id;
  55         u64                     seq;
  56         struct vdc_req_entry    rq_arr[VDC_TX_RING_SIZE];
  57
  58         unsigned long           ring_cookies;
  59
  60         u64                     max_xfer_size;
  61         u32                     vdisk_block_size;
  62
  63         /* The server fills these in for us in the disk attribute
  64          * ACK packet.
  65          */
  66         u64                     operations;
  67         u32                     vdisk_size;
  68         u8                      vdisk_type;
  69         u8                      vdisk_mtype;
  70
  71         char                    disk_name[32];
  72 };
  73
  74 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
  75 {
  76         return container_of(vio, struct vdc_port, vio);
  77 }
  78
  79 /* Ordered from largest major to lowest */
  80 static struct vio_version vdc_versions[] = {
  81         { .major = 1, .minor = 1 },
  82         { .major = 1, .minor = 0 },
  83 };
  84
  85 static inline int vdc_version_supported(struct vdc_port *port,
  86                                         u16 major, u16 minor)
  87 {
  88         return port->vio.ver.major == major && port->vio.ver.minor >= minor;
  89 }
  90
  91 #define VDCBLK_NAME     "vdisk"
  92 static int vdc_major;
  93 #define PARTITION_SHIFT 3
  94
  95 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
  96 {
  97         return vio_dring_avail(dr, VDC_TX_RING_SIZE);
  98 }
  99
 100 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 101 {
 102         struct gendisk *disk = bdev->bd_disk;
 103         sector_t nsect = get_capacity(disk);
 104         sector_t cylinders = nsect;
 105
 106         geo->heads = 0xff;
 107         geo->sectors = 0x3f;
 108         sector_div(cylinders, geo->heads * geo->sectors);
 109         geo->cylinders = cylinders;
 110         if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
 111                 geo->cylinders = 0xffff;
 112
 113         return 0;
 114 }
 115
 116 /* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
 117  * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
 118  * Needed to be able to install inside an ldom from an iso image.
 119  */
 120 static int vdc_ioctl(struct block_device *bdev, fmode_t mode,
 121                      unsigned command, unsigned long argument)
 122 {
 123         int i;
 124         struct gendisk *disk;
 125
 126         switch (command) {
 127         case CDROMMULTISESSION:
 128                 pr_debug(PFX "Multisession CDs not supported\n");
 129                 for (i = 0; i < sizeof(struct cdrom_multisession); i++)
 130                         if (put_user(0, (char __user *)(argument + i)))
 131                                 return -EFAULT;
 132                 return 0;
 133
 134         case CDROM_GET_CAPABILITY:
 135                 disk = bdev->bd_disk;
 136
 137                 if (bdev->bd_disk && (disk->flags & GENHD_FL_CD))
 138                         return 0;
 139                 return -EINVAL;
 140
 141         default:
 142                 pr_debug(PFX "ioctl %08x not supported\n", command);
 143                 return -EINVAL;
 144         }
 145 }
 146
 147 static const struct block_device_operations vdc_fops = {
 148         .owner          = THIS_MODULE,
 149         .getgeo         = vdc_getgeo,
 150         .ioctl          = vdc_ioctl,
 151 };
 152
 153 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
 154 {
 155         if (vio->cmp &&
 156             (waiting_for == -1 ||
 157              vio->cmp->waiting_for == waiting_for)) {
 158                 vio->cmp->err = err;
 159                 complete(&vio->cmp->com);
 160                 vio->cmp = NULL;
 161         }
 162 }
 163
 164 static void vdc_handshake_complete(struct vio_driver_state *vio)
 165 {
 166         vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
 167 }
 168
 169 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
 170 {
 171         struct vio_msg_tag *pkt = arg;
 172
 173         printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
 174                pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
 175         printk(KERN_ERR PFX "Resetting connection.\n");
 176
 177         ldc_disconnect(port->vio.lp);
 178
 179         return -ECONNRESET;
 180 }
 181
 182 static int vdc_send_attr(struct vio_driver_state *vio)
 183 {
 184         struct vdc_port *port = to_vdc_port(vio);
 185         struct vio_disk_attr_info pkt;
 186
 187         memset(&pkt, 0, sizeof(pkt));
 188
 189         pkt.tag.type = VIO_TYPE_CTRL;
 190         pkt.tag.stype = VIO_SUBTYPE_INFO;
 191         pkt.tag.stype_env = VIO_ATTR_INFO;
 192         pkt.tag.sid = vio_send_sid(vio);
 193
 194         pkt.xfer_mode = VIO_DRING_MODE;
 195         pkt.vdisk_block_size = port->vdisk_block_size;
 196         pkt.max_xfer_size = port->max_xfer_size;
 197
 198         viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 199                pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
 200
 201         return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
 202 }
 203
 204 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
 205 {
 206         struct vdc_port *port = to_vdc_port(vio);
 207         struct vio_disk_attr_info *pkt = arg;
 208
 209         viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
 210                "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 211                pkt->tag.stype, pkt->operations,
 212                pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
 213                pkt->xfer_mode, pkt->vdisk_block_size,
 214                pkt->max_xfer_size);
 215
 216         if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
 217                 switch (pkt->vdisk_type) {
 218                 case VD_DISK_TYPE_DISK:
 219                 case VD_DISK_TYPE_SLICE:
 220                         break;
 221
 222                 default:
 223                         printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
 224                                vio->name, pkt->vdisk_type);
 225                         return -ECONNRESET;
 226                 }
 227
 228                 if (pkt->vdisk_block_size > port->vdisk_block_size) {
 229                         printk(KERN_ERR PFX "%s: BLOCK size increased "
 230                                "%u --> %u\n",
 231                                vio->name,
 232                                port->vdisk_block_size, pkt->vdisk_block_size);
 233                         return -ECONNRESET;
 234                 }
 235
 236                 port->operations = pkt->operations;
 237                 port->vdisk_type = pkt->vdisk_type;
 238                 if (vdc_version_supported(port, 1, 1)) {
 239                         port->vdisk_size = pkt->vdisk_size;
 240                         port->vdisk_mtype = pkt->vdisk_mtype;
 241                 }
 242                 if (pkt->max_xfer_size < port->max_xfer_size)
 243                         port->max_xfer_size = pkt->max_xfer_size;
 244                 port->vdisk_block_size = pkt->vdisk_block_size;
 245                 return 0;
 246         } else {
 247                 printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
 248
 249                 return -ECONNRESET;
 250         }
 251 }
 252
 253 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
 254 {
 255         int err = desc->status;
 256
 257         vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
 258 }
 259
 260 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
 261                         unsigned int index)
 262 {
 263         struct vio_disk_desc *desc = vio_dring_entry(dr, index);
 264         struct vdc_req_entry *rqe = &port->rq_arr[index];
 265         struct request *req;
 266
 267         if (unlikely(desc->hdr.state != VIO_DESC_DONE))
 268                 return;
 269
 270         ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
 271         desc->hdr.state = VIO_DESC_FREE;
 272         dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1);
 273
 274         req = rqe->req;
 275         if (req == NULL) {
 276                 vdc_end_special(port, desc);
 277                 return;
 278         }
 279
 280         rqe->req = NULL;
 281
 282         __blk_end_request(req, (desc->status ? -EIO : 0), desc->size);
 283
 284         /* restart blk queue when ring is half emptied */
 285         if (blk_queue_stopped(port->disk->queue) &&
 286             vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50)
 287                 blk_start_queue(port->disk->queue);
 288 }
 289
 290 static int vdc_ack(struct vdc_port *port, void *msgbuf)
 291 {
 292         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 293         struct vio_dring_data *pkt = msgbuf;
 294
 295         if (unlikely(pkt->dring_ident != dr->ident ||
 296                      pkt->start_idx != pkt->end_idx ||
 297                      pkt->start_idx >= VDC_TX_RING_SIZE))
 298                 return 0;
 299
 300         vdc_end_one(port, dr, pkt->start_idx);
 301
 302         return 0;
 303 }
 304
 305 static int vdc_nack(struct vdc_port *port, void *msgbuf)
 306 {
 307         /* XXX Implement me XXX */
 308         return 0;
 309 }
 310
 311 static void vdc_event(void *arg, int event)
 312 {
 313         struct vdc_port *port = arg;
 314         struct vio_driver_state *vio = &port->vio;
 315         unsigned long flags;
 316         int err;
 317
 318         spin_lock_irqsave(&vio->lock, flags);
 319
 320         if (unlikely(event == LDC_EVENT_RESET ||
 321                      event == LDC_EVENT_UP)) {
 322                 vio_link_state_change(vio, event);
 323                 spin_unlock_irqrestore(&vio->lock, flags);
 324                 return;
 325         }
 326
 327         if (unlikely(event != LDC_EVENT_DATA_READY)) {
 328                 printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
 329                 spin_unlock_irqrestore(&vio->lock, flags);
 330                 return;
 331         }
 332
 333         err = 0;
 334         while (1) {
 335                 union {
 336                         struct vio_msg_tag tag;
 337                         u64 raw[8];
 338                 } msgbuf;
 339
 340                 err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
 341                 if (unlikely(err < 0)) {
 342                         if (err == -ECONNRESET)
 343                                 vio_conn_reset(vio);
 344                         break;
 345                 }
 346                 if (err == 0)
 347                         break;
 348                 viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
 349                        msgbuf.tag.type,
 350                        msgbuf.tag.stype,
 351                        msgbuf.tag.stype_env,
 352                        msgbuf.tag.sid);
 353                 err = vio_validate_sid(vio, &msgbuf.tag);
 354                 if (err < 0)
 355                         break;
 356
 357                 if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
 358                         if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
 359                                 err = vdc_ack(port, &msgbuf);
 360                         else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
 361                                 err = vdc_nack(port, &msgbuf);
 362                         else
 363                                 err = vdc_handle_unknown(port, &msgbuf);
 364                 } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
 365                         err = vio_control_pkt_engine(vio, &msgbuf);
 366                 } else {
 367                         err = vdc_handle_unknown(port, &msgbuf);
 368                 }
 369                 if (err < 0)
 370                         break;
 371         }
 372         if (err < 0)
 373                 vdc_finish(&port->vio, err, WAITING_FOR_ANY);
 374         spin_unlock_irqrestore(&vio->lock, flags);
 375 }
 376
 377 static int __vdc_tx_trigger(struct vdc_port *port)
 378 {
 379         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 380         struct vio_dring_data hdr = {
 381                 .tag = {
 382                         .type           = VIO_TYPE_DATA,
 383                         .stype          = VIO_SUBTYPE_INFO,
 384                         .stype_env      = VIO_DRING_DATA,
 385                         .sid            = vio_send_sid(&port->vio),
 386                 },
 387                 .dring_ident            = dr->ident,
 388                 .start_idx              = dr->prod,
 389                 .end_idx                = dr->prod,
 390         };
 391         int err, delay;
 392
 393         hdr.seq = dr->snd_nxt;
 394         delay = 1;
 395         do {
 396                 err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
 397                 if (err > 0) {
 398                         dr->snd_nxt++;
 399                         break;
 400                 }
 401                 udelay(delay);
 402                 if ((delay <<= 1) > 128)
 403                         delay = 128;
 404         } while (err == -EAGAIN);
 405
 406         return err;
 407 }
 408
 409 static int __send_request(struct request *req)
 410 {
 411         struct vdc_port *port = req->rq_disk->private_data;
 412         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 413         struct scatterlist sg[port->ring_cookies];
 414         struct vdc_req_entry *rqe;
 415         struct vio_disk_desc *desc;
 416         unsigned int map_perm;
 417         int nsg, err, i;
 418         u64 len;
 419         u8 op;
 420
 421         map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 422
 423         if (rq_data_dir(req) == READ) {
 424                 map_perm |= LDC_MAP_W;
 425                 op = VD_OP_BREAD;
 426         } else {
 427                 map_perm |= LDC_MAP_R;
 428                 op = VD_OP_BWRITE;
 429         }
 430
 431         sg_init_table(sg, port->ring_cookies);
 432         nsg = blk_rq_map_sg(req->q, req, sg);
 433
 434         len = 0;
 435         for (i = 0; i < nsg; i++)
 436                 len += sg[i].length;
 437
 438         desc = vio_dring_cur(dr);
 439
 440         err = ldc_map_sg(port->vio.lp, sg, nsg,
 441                          desc->cookies, port->ring_cookies,
 442                          map_perm);
 443         if (err < 0) {
 444                 printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
 445                 return err;
 446         }
 447
 448         rqe = &port->rq_arr[dr->prod];
 449         rqe->req = req;
 450
 451         desc->hdr.ack = VIO_ACK_ENABLE;
 452         desc->req_id = port->req_id;
 453         desc->operation = op;
 454         if (port->vdisk_type == VD_DISK_TYPE_DISK) {
 455                 desc->slice = 0xff;
 456         } else {
 457                 desc->slice = 0;
 458         }
 459         desc->status = ~0;
 460         desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
 461         desc->size = len;
 462         desc->ncookies = err;
 463
 464         /* This has to be a non-SMP write barrier because we are writing
 465          * to memory which is shared with the peer LDOM.
 466          */
 467         wmb();
 468         desc->hdr.state = VIO_DESC_READY;
 469
 470         err = __vdc_tx_trigger(port);
 471         if (err < 0) {
 472                 printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
 473         } else {
 474                 port->req_id++;
 475                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
 476         }
 477
 478         return err;
 479 }
 480
 481 static void do_vdc_request(struct request_queue *rq)
 482 {
 483         struct request *req;
 484
 485         while ((req = blk_peek_request(rq)) != NULL) {
 486                 struct vdc_port *port;
 487                 struct vio_dring_state *dr;
 488
 489                 port = req->rq_disk->private_data;
 490                 dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 491                 if (unlikely(vdc_tx_dring_avail(dr) < 1))
 492                         goto wait;
 493
 494                 blk_start_request(req);
 495
 496                 if (__send_request(req) < 0) {
 497                         blk_requeue_request(rq, req);
 498 wait:
 499                         /* Avoid pointless unplugs. */
 500                         blk_stop_queue(rq);
 501                         break;
 502                 }
 503         }
 504 }
 505
 506 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
 507 {
 508         struct vio_dring_state *dr;
 509         struct vio_completion comp;
 510         struct vio_disk_desc *desc;
 511         unsigned int map_perm;
 512         unsigned long flags;
 513         int op_len, err;
 514         void *req_buf;
 515
 516         if (!(((u64)1 << (u64)op) & port->operations))
 517                 return -EOPNOTSUPP;
 518
 519         switch (op) {
 520         case VD_OP_BREAD:
 521         case VD_OP_BWRITE:
 522         default:
 523                 return -EINVAL;
 524
 525         case VD_OP_FLUSH:
 526                 op_len = 0;
 527                 map_perm = 0;
 528                 break;
 529
 530         case VD_OP_GET_WCE:
 531                 op_len = sizeof(u32);
 532                 map_perm = LDC_MAP_W;
 533                 break;
 534
 535         case VD_OP_SET_WCE:
 536                 op_len = sizeof(u32);
 537                 map_perm = LDC_MAP_R;
 538                 break;
 539
 540         case VD_OP_GET_VTOC:
 541                 op_len = sizeof(struct vio_disk_vtoc);
 542                 map_perm = LDC_MAP_W;
 543                 break;
 544
 545         case VD_OP_SET_VTOC:
 546                 op_len = sizeof(struct vio_disk_vtoc);
 547                 map_perm = LDC_MAP_R;
 548                 break;
 549
 550         case VD_OP_GET_DISKGEOM:
 551                 op_len = sizeof(struct vio_disk_geom);
 552                 map_perm = LDC_MAP_W;
 553                 break;
 554
 555         case VD_OP_SET_DISKGEOM:
 556                 op_len = sizeof(struct vio_disk_geom);
 557                 map_perm = LDC_MAP_R;
 558                 break;
 559
 560         case VD_OP_SCSICMD:
 561                 op_len = 16;
 562                 map_perm = LDC_MAP_RW;
 563                 break;
 564
 565         case VD_OP_GET_DEVID:
 566                 op_len = sizeof(struct vio_disk_devid);
 567                 map_perm = LDC_MAP_W;
 568                 break;
 569
 570         case VD_OP_GET_EFI:
 571         case VD_OP_SET_EFI:
 572                 return -EOPNOTSUPP;
 573                 break;
 574         };
 575
 576         map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 577
 578         op_len = (op_len + 7) & ~7;
 579         req_buf = kzalloc(op_len, GFP_KERNEL);
 580         if (!req_buf)
 581                 return -ENOMEM;
 582
 583         if (len > op_len)
 584                 len = op_len;
 585
 586         if (map_perm & LDC_MAP_R)
 587                 memcpy(req_buf, buf, len);
 588
 589         spin_lock_irqsave(&port->vio.lock, flags);
 590
 591         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 592
 593         /* XXX If we want to use this code generically we have to
 594          * XXX handle TX ring exhaustion etc.
 595          */
 596         desc = vio_dring_cur(dr);
 597
 598         err = ldc_map_single(port->vio.lp, req_buf, op_len,
 599                              desc->cookies, port->ring_cookies,
 600                              map_perm);
 601         if (err < 0) {
 602                 spin_unlock_irqrestore(&port->vio.lock, flags);
 603                 kfree(req_buf);
 604                 return err;
 605         }
 606
 607         init_completion(&comp.com);
 608         comp.waiting_for = WAITING_FOR_GEN_CMD;
 609         port->vio.cmp = &comp;
 610
 611         desc->hdr.ack = VIO_ACK_ENABLE;
 612         desc->req_id = port->req_id;
 613         desc->operation = op;
 614         desc->slice = 0;
 615         desc->status = ~0;
 616         desc->offset = 0;
 617         desc->size = op_len;
 618         desc->ncookies = err;
 619
 620         /* This has to be a non-SMP write barrier because we are writing
 621          * to memory which is shared with the peer LDOM.
 622          */
 623         wmb();
 624         desc->hdr.state = VIO_DESC_READY;
 625
 626         err = __vdc_tx_trigger(port);
 627         if (err >= 0) {
 628                 port->req_id++;
 629                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
 630                 spin_unlock_irqrestore(&port->vio.lock, flags);
 631
 632                 wait_for_completion(&comp.com);
 633                 err = comp.err;
 634         } else {
 635                 port->vio.cmp = NULL;
 636                 spin_unlock_irqrestore(&port->vio.lock, flags);
 637         }
 638
 639         if (map_perm & LDC_MAP_W)
 640                 memcpy(buf, req_buf, len);
 641
 642         kfree(req_buf);
 643
 644         return err;
 645 }
 646
 647 static int vdc_alloc_tx_ring(struct vdc_port *port)
 648 {
 649         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 650         unsigned long len, entry_size;
 651         int ncookies;
 652         void *dring;
 653
 654         entry_size = sizeof(struct vio_disk_desc) +
 655                 (sizeof(struct ldc_trans_cookie) * port->ring_cookies);
 656         len = (VDC_TX_RING_SIZE * entry_size);
 657
 658         ncookies = VIO_MAX_RING_COOKIES;
 659         dring = ldc_alloc_exp_dring(port->vio.lp, len,
 660                                     dr->cookies, &ncookies,
 661                                     (LDC_MAP_SHADOW |
 662                                      LDC_MAP_DIRECT |
 663                                      LDC_MAP_RW));
 664         if (IS_ERR(dring))
 665                 return PTR_ERR(dring);
 666
 667         dr->base = dring;
 668         dr->entry_size = entry_size;
 669         dr->num_entries = VDC_TX_RING_SIZE;
 670         dr->prod = dr->cons = 0;
 671         dr->pending = VDC_TX_RING_SIZE;
 672         dr->ncookies = ncookies;
 673
 674         return 0;
 675 }
 676
 677 static void vdc_free_tx_ring(struct vdc_port *port)
 678 {
 679         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 680
 681         if (dr->base) {
 682                 ldc_free_exp_dring(port->vio.lp, dr->base,
 683                                    (dr->entry_size * dr->num_entries),
 684                                    dr->cookies, dr->ncookies);
 685                 dr->base = NULL;
 686                 dr->entry_size = 0;
 687                 dr->num_entries = 0;
 688                 dr->pending = 0;
 689                 dr->ncookies = 0;
 690         }
 691 }
 692
 693 static int probe_disk(struct vdc_port *port)
 694 {
 695         struct vio_completion comp;
 696         struct request_queue *q;
 697         struct gendisk *g;
 698         int err;
 699
 700         init_completion(&comp.com);
 701         comp.err = 0;
 702         comp.waiting_for = WAITING_FOR_LINK_UP;
 703         port->vio.cmp = &comp;
 704
 705         vio_port_up(&port->vio);
 706
 707         wait_for_completion(&comp.com);
 708         if (comp.err)
 709                 return comp.err;
 710
 711         if (vdc_version_supported(port, 1, 1)) {
 712                 /* vdisk_size should be set during the handshake, if it wasn't
 713                  * then the underlying disk is reserved by another system
 714                  */
 715                 if (port->vdisk_size == -1)
 716                         return -ENODEV;
 717         } else {
 718                 struct vio_disk_geom geom;
 719
 720                 err = generic_request(port, VD_OP_GET_DISKGEOM,
 721                                       &geom, sizeof(geom));
 722                 if (err < 0) {
 723                         printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
 724                                "error %d\n", err);
 725                         return err;
 726                 }
 727                 port->vdisk_size = ((u64)geom.num_cyl *
 728                                     (u64)geom.num_hd *
 729                                     (u64)geom.num_sec);
 730         }
 731
 732         q = blk_init_queue(do_vdc_request, &port->vio.lock);
 733         if (!q) {
 734                 printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
 735                        port->vio.name);
 736                 return -ENOMEM;
 737         }
 738         g = alloc_disk(1 << PARTITION_SHIFT);
 739         if (!g) {
 740                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
 741                        port->vio.name);
 742                 blk_cleanup_queue(q);
 743                 return -ENOMEM;
 744         }
 745
 746         port->disk = g;
 747
 748         /* Each segment in a request is up to an aligned page in size. */
 749         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
 750         blk_queue_max_segment_size(q, PAGE_SIZE);
 751
 752         blk_queue_max_segments(q, port->ring_cookies);
 753         blk_queue_max_hw_sectors(q, port->max_xfer_size);
 754         g->major = vdc_major;
 755         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
 756         strcpy(g->disk_name, port->disk_name);
 757
 758         g->fops = &vdc_fops;
 759         g->queue = q;
 760         g->private_data = port;
 761         g->driverfs_dev = &port->vio.vdev->dev;
 762
 763         set_capacity(g, port->vdisk_size);
 764
 765         if (vdc_version_supported(port, 1, 1)) {
 766                 switch (port->vdisk_mtype) {
 767                 case VD_MEDIA_TYPE_CD:
 768                         pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
 769                         g->flags |= GENHD_FL_CD;
 770                         g->flags |= GENHD_FL_REMOVABLE;
 771                         set_disk_ro(g, 1);
 772                         break;
 773
 774                 case VD_MEDIA_TYPE_DVD:
 775                         pr_info(PFX "Virtual DVD %s\n", port->disk_name);
 776                         g->flags |= GENHD_FL_CD;
 777                         g->flags |= GENHD_FL_REMOVABLE;
 778                         set_disk_ro(g, 1);
 779                         break;
 780
 781                 case VD_MEDIA_TYPE_FIXED:
 782                         pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
 783                         break;
 784                 }
 785         }
 786
 787         pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
 788                g->disk_name,
 789                port->vdisk_size, (port->vdisk_size >> (20 - 9)),
 790                port->vio.ver.major, port->vio.ver.minor);
 791
 792         add_disk(g);
 793
 794         return 0;
 795 }
 796
 797 static struct ldc_channel_config vdc_ldc_cfg = {
 798         .event          = vdc_event,
 799         .mtu            = 64,
 800         .mode           = LDC_MODE_UNRELIABLE,
 801 };
 802
 803 static struct vio_driver_ops vdc_vio_ops = {
 804         .send_attr              = vdc_send_attr,
 805         .handle_attr            = vdc_handle_attr,
 806         .handshake_complete     = vdc_handshake_complete,
 807 };
 808
 809 static void print_version(void)
 810 {
 811         static int version_printed;
 812
 813         if (version_printed++ == 0)
 814                 printk(KERN_INFO "%s", version);
 815 }
 816
 817 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 818 {
 819         struct mdesc_handle *hp;
 820         struct vdc_port *port;
 821         int err;
 822
 823         print_version();
 824
 825         hp = mdesc_grab();
 826
 827         err = -ENODEV;
 828         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
 829                 printk(KERN_ERR PFX "Port id [%llu] too large.\n",
 830                        vdev->dev_no);
 831                 goto err_out_release_mdesc;
 832         }
 833
 834         port = kzalloc(sizeof(*port), GFP_KERNEL);
 835         err = -ENOMEM;
 836         if (!port) {
 837                 printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
 838                 goto err_out_release_mdesc;
 839         }
 840
 841         if (vdev->dev_no >= 26)
 842                 snprintf(port->disk_name, sizeof(port->disk_name),
 843                          VDCBLK_NAME "%c%c",
 844                          'a' + ((int)vdev->dev_no / 26) - 1,
 845                          'a' + ((int)vdev->dev_no % 26));
 846         else
 847                 snprintf(port->disk_name, sizeof(port->disk_name),
 848                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
 849         port->vdisk_size = -1;
 850
 851         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
 852                               vdc_versions, ARRAY_SIZE(vdc_versions),
 853                               &vdc_vio_ops, port->disk_name);
 854         if (err)
 855                 goto err_out_free_port;
 856
 857         port->vdisk_block_size = 512;
 858         port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
 859         port->ring_cookies = ((port->max_xfer_size *
 860                                port->vdisk_block_size) / PAGE_SIZE) + 2;
 861
 862         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
 863         if (err)
 864                 goto err_out_free_port;
 865
 866         err = vdc_alloc_tx_ring(port);
 867         if (err)
 868                 goto err_out_free_ldc;
 869
 870         err = probe_disk(port);
 871         if (err)
 872                 goto err_out_free_tx_ring;
 873
 874         dev_set_drvdata(&vdev->dev, port);
 875
 876         mdesc_release(hp);
 877
 878         return 0;
 879
 880 err_out_free_tx_ring:
 881         vdc_free_tx_ring(port);
 882
 883 err_out_free_ldc:
 884         vio_ldc_free(&port->vio);
 885
 886 err_out_free_port:
 887         kfree(port);
 888
 889 err_out_release_mdesc:
 890         mdesc_release(hp);
 891         return err;
 892 }
 893
 894 static int vdc_port_remove(struct vio_dev *vdev)
 895 {
 896         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
 897
 898         if (port) {
 899                 del_timer_sync(&port->vio.timer);
 900
 901                 vdc_free_tx_ring(port);
 902                 vio_ldc_free(&port->vio);
 903
 904                 dev_set_drvdata(&vdev->dev, NULL);
 905
 906                 kfree(port);
 907         }
 908         return 0;
 909 }
 910
 911 static const struct vio_device_id vdc_port_match[] = {
 912         {
 913                 .type = "vdc-port",
 914         },
 915         {},
 916 };
 917 MODULE_DEVICE_TABLE(vio, vdc_port_match);
 918
 919 static struct vio_driver vdc_port_driver = {
 920         .id_table       = vdc_port_match,
 921         .probe          = vdc_port_probe,
 922         .remove         = vdc_port_remove,
 923         .name           = "vdc_port",
 924 };
 925
 926 static int __init vdc_init(void)
 927 {
 928         int err;
 929
 930         err = register_blkdev(0, VDCBLK_NAME);
 931         if (err < 0)
 932                 goto out_err;
 933
 934         vdc_major = err;
 935
 936         err = vio_register_driver(&vdc_port_driver);
 937         if (err)
 938                 goto out_unregister_blkdev;
 939
 940         return 0;
 941
 942 out_unregister_blkdev:
 943         unregister_blkdev(vdc_major, VDCBLK_NAME);
 944         vdc_major = 0;
 945
 946 out_err:
 947         return err;
 948 }
 949
 950 static void __exit vdc_exit(void)
 951 {
 952         vio_unregister_driver(&vdc_port_driver);
 953         unregister_blkdev(vdc_major, VDCBLK_NAME);
 954 }
 955
 956 module_init(vdc_init);
 957 module_exit(vdc_exit);