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         struct vio_disk_vtoc    label;
  74 };
  75
  76 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
  77 {
  78         return container_of(vio, struct vdc_port, vio);
  79 }
  80
  81 /* Ordered from largest major to lowest */
  82 static struct vio_version vdc_versions[] = {
  83         { .major = 1, .minor = 1 },
  84         { .major = 1, .minor = 0 },
  85 };
  86
  87 static inline int vdc_version_supported(struct vdc_port *port,
  88                                         u16 major, u16 minor)
  89 {
  90         return port->vio.ver.major == major && port->vio.ver.minor >= minor;
  91 }
  92
  93 #define VDCBLK_NAME     "vdisk"
  94 static int vdc_major;
  95 #define PARTITION_SHIFT 3
  96
  97 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
  98 {
  99         return vio_dring_avail(dr, VDC_TX_RING_SIZE);
 100 }
 101
 102 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 103 {
 104         struct gendisk *disk = bdev->bd_disk;
 105         sector_t nsect = get_capacity(disk);
 106         sector_t cylinders = nsect;
 107
 108         geo->heads = 0xff;
 109         geo->sectors = 0x3f;
 110         sector_div(cylinders, geo->heads * geo->sectors);
 111         geo->cylinders = cylinders;
 112         if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
 113                 geo->cylinders = 0xffff;
 114
 115         return 0;
 116 }
 117
 118 /* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
 119  * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
 120  * Needed to be able to install inside an ldom from an iso image.
 121  */
 122 static int vdc_ioctl(struct block_device *bdev, fmode_t mode,
 123                      unsigned command, unsigned long argument)
 124 {
 125         int i;
 126         struct gendisk *disk;
 127
 128         switch (command) {
 129         case CDROMMULTISESSION:
 130                 pr_debug(PFX "Multisession CDs not supported\n");
 131                 for (i = 0; i < sizeof(struct cdrom_multisession); i++)
 132                         if (put_user(0, (char __user *)(argument + i)))
 133                                 return -EFAULT;
 134                 return 0;
 135
 136         case CDROM_GET_CAPABILITY:
 137                 disk = bdev->bd_disk;
 138
 139                 if (bdev->bd_disk && (disk->flags & GENHD_FL_CD))
 140                         return 0;
 141                 return -EINVAL;
 142
 143         default:
 144                 pr_debug(PFX "ioctl %08x not supported\n", command);
 145                 return -EINVAL;
 146         }
 147 }
 148
 149 static const struct block_device_operations vdc_fops = {
 150         .owner          = THIS_MODULE,
 151         .getgeo         = vdc_getgeo,
 152         .ioctl          = vdc_ioctl,
 153 };
 154
 155 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
 156 {
 157         if (vio->cmp &&
 158             (waiting_for == -1 ||
 159              vio->cmp->waiting_for == waiting_for)) {
 160                 vio->cmp->err = err;
 161                 complete(&vio->cmp->com);
 162                 vio->cmp = NULL;
 163         }
 164 }
 165
 166 static void vdc_handshake_complete(struct vio_driver_state *vio)
 167 {
 168         vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
 169 }
 170
 171 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
 172 {
 173         struct vio_msg_tag *pkt = arg;
 174
 175         printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
 176                pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
 177         printk(KERN_ERR PFX "Resetting connection.\n");
 178
 179         ldc_disconnect(port->vio.lp);
 180
 181         return -ECONNRESET;
 182 }
 183
 184 static int vdc_send_attr(struct vio_driver_state *vio)
 185 {
 186         struct vdc_port *port = to_vdc_port(vio);
 187         struct vio_disk_attr_info pkt;
 188
 189         memset(&pkt, 0, sizeof(pkt));
 190
 191         pkt.tag.type = VIO_TYPE_CTRL;
 192         pkt.tag.stype = VIO_SUBTYPE_INFO;
 193         pkt.tag.stype_env = VIO_ATTR_INFO;
 194         pkt.tag.sid = vio_send_sid(vio);
 195
 196         pkt.xfer_mode = VIO_DRING_MODE;
 197         pkt.vdisk_block_size = port->vdisk_block_size;
 198         pkt.max_xfer_size = port->max_xfer_size;
 199
 200         viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 201                pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
 202
 203         return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
 204 }
 205
 206 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
 207 {
 208         struct vdc_port *port = to_vdc_port(vio);
 209         struct vio_disk_attr_info *pkt = arg;
 210
 211         viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
 212                "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 213                pkt->tag.stype, pkt->operations,
 214                pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
 215                pkt->xfer_mode, pkt->vdisk_block_size,
 216                pkt->max_xfer_size);
 217
 218         if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
 219                 switch (pkt->vdisk_type) {
 220                 case VD_DISK_TYPE_DISK:
 221                 case VD_DISK_TYPE_SLICE:
 222                         break;
 223
 224                 default:
 225                         printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
 226                                vio->name, pkt->vdisk_type);
 227                         return -ECONNRESET;
 228                 }
 229
 230                 if (pkt->vdisk_block_size > port->vdisk_block_size) {
 231                         printk(KERN_ERR PFX "%s: BLOCK size increased "
 232                                "%u --> %u\n",
 233                                vio->name,
 234                                port->vdisk_block_size, pkt->vdisk_block_size);
 235                         return -ECONNRESET;
 236                 }
 237
 238                 port->operations = pkt->operations;
 239                 port->vdisk_type = pkt->vdisk_type;
 240                 if (vdc_version_supported(port, 1, 1)) {
 241                         port->vdisk_size = pkt->vdisk_size;
 242                         port->vdisk_mtype = pkt->vdisk_mtype;
 243                 }
 244                 if (pkt->max_xfer_size < port->max_xfer_size)
 245                         port->max_xfer_size = pkt->max_xfer_size;
 246                 port->vdisk_block_size = pkt->vdisk_block_size;
 247                 return 0;
 248         } else {
 249                 printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
 250
 251                 return -ECONNRESET;
 252         }
 253 }
 254
 255 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
 256 {
 257         int err = desc->status;
 258
 259         vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
 260 }
 261
 262 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
 263                         unsigned int index)
 264 {
 265         struct vio_disk_desc *desc = vio_dring_entry(dr, index);
 266         struct vdc_req_entry *rqe = &port->rq_arr[index];
 267         struct request *req;
 268
 269         if (unlikely(desc->hdr.state != VIO_DESC_DONE))
 270                 return;
 271
 272         ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
 273         desc->hdr.state = VIO_DESC_FREE;
 274         dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1);
 275
 276         req = rqe->req;
 277         if (req == NULL) {
 278                 vdc_end_special(port, desc);
 279                 return;
 280         }
 281
 282         rqe->req = NULL;
 283
 284         __blk_end_request(req, (desc->status ? -EIO : 0), desc->size);
 285
 286         /* restart blk queue when ring is half emptied */
 287         if (blk_queue_stopped(port->disk->queue) &&
 288             vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50)
 289                 blk_start_queue(port->disk->queue);
 290 }
 291
 292 static int vdc_ack(struct vdc_port *port, void *msgbuf)
 293 {
 294         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 295         struct vio_dring_data *pkt = msgbuf;
 296
 297         if (unlikely(pkt->dring_ident != dr->ident ||
 298                      pkt->start_idx != pkt->end_idx ||
 299                      pkt->start_idx >= VDC_TX_RING_SIZE))
 300                 return 0;
 301
 302         vdc_end_one(port, dr, pkt->start_idx);
 303
 304         return 0;
 305 }
 306
 307 static int vdc_nack(struct vdc_port *port, void *msgbuf)
 308 {
 309         /* XXX Implement me XXX */
 310         return 0;
 311 }
 312
 313 static void vdc_event(void *arg, int event)
 314 {
 315         struct vdc_port *port = arg;
 316         struct vio_driver_state *vio = &port->vio;
 317         unsigned long flags;
 318         int err;
 319
 320         spin_lock_irqsave(&vio->lock, flags);
 321
 322         if (unlikely(event == LDC_EVENT_RESET ||
 323                      event == LDC_EVENT_UP)) {
 324                 vio_link_state_change(vio, event);
 325                 spin_unlock_irqrestore(&vio->lock, flags);
 326                 return;
 327         }
 328
 329         if (unlikely(event != LDC_EVENT_DATA_READY)) {
 330                 printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
 331                 spin_unlock_irqrestore(&vio->lock, flags);
 332                 return;
 333         }
 334
 335         err = 0;
 336         while (1) {
 337                 union {
 338                         struct vio_msg_tag tag;
 339                         u64 raw[8];
 340                 } msgbuf;
 341
 342                 err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
 343                 if (unlikely(err < 0)) {
 344                         if (err == -ECONNRESET)
 345                                 vio_conn_reset(vio);
 346                         break;
 347                 }
 348                 if (err == 0)
 349                         break;
 350                 viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
 351                        msgbuf.tag.type,
 352                        msgbuf.tag.stype,
 353                        msgbuf.tag.stype_env,
 354                        msgbuf.tag.sid);
 355                 err = vio_validate_sid(vio, &msgbuf.tag);
 356                 if (err < 0)
 357                         break;
 358
 359                 if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
 360                         if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
 361                                 err = vdc_ack(port, &msgbuf);
 362                         else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
 363                                 err = vdc_nack(port, &msgbuf);
 364                         else
 365                                 err = vdc_handle_unknown(port, &msgbuf);
 366                 } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
 367                         err = vio_control_pkt_engine(vio, &msgbuf);
 368                 } else {
 369                         err = vdc_handle_unknown(port, &msgbuf);
 370                 }
 371                 if (err < 0)
 372                         break;
 373         }
 374         if (err < 0)
 375                 vdc_finish(&port->vio, err, WAITING_FOR_ANY);
 376         spin_unlock_irqrestore(&vio->lock, flags);
 377 }
 378
 379 static int __vdc_tx_trigger(struct vdc_port *port)
 380 {
 381         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 382         struct vio_dring_data hdr = {
 383                 .tag = {
 384                         .type           = VIO_TYPE_DATA,
 385                         .stype          = VIO_SUBTYPE_INFO,
 386                         .stype_env      = VIO_DRING_DATA,
 387                         .sid            = vio_send_sid(&port->vio),
 388                 },
 389                 .dring_ident            = dr->ident,
 390                 .start_idx              = dr->prod,
 391                 .end_idx                = dr->prod,
 392         };
 393         int err, delay;
 394
 395         hdr.seq = dr->snd_nxt;
 396         delay = 1;
 397         do {
 398                 err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
 399                 if (err > 0) {
 400                         dr->snd_nxt++;
 401                         break;
 402                 }
 403                 udelay(delay);
 404                 if ((delay <<= 1) > 128)
 405                         delay = 128;
 406         } while (err == -EAGAIN);
 407
 408         return err;
 409 }
 410
 411 static int __send_request(struct request *req)
 412 {
 413         struct vdc_port *port = req->rq_disk->private_data;
 414         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 415         struct scatterlist sg[port->ring_cookies];
 416         struct vdc_req_entry *rqe;
 417         struct vio_disk_desc *desc;
 418         unsigned int map_perm;
 419         int nsg, err, i;
 420         u64 len;
 421         u8 op;
 422
 423         map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 424
 425         if (rq_data_dir(req) == READ) {
 426                 map_perm |= LDC_MAP_W;
 427                 op = VD_OP_BREAD;
 428         } else {
 429                 map_perm |= LDC_MAP_R;
 430                 op = VD_OP_BWRITE;
 431         }
 432
 433         sg_init_table(sg, port->ring_cookies);
 434         nsg = blk_rq_map_sg(req->q, req, sg);
 435
 436         len = 0;
 437         for (i = 0; i < nsg; i++)
 438                 len += sg[i].length;
 439
 440         desc = vio_dring_cur(dr);
 441
 442         err = ldc_map_sg(port->vio.lp, sg, nsg,
 443                          desc->cookies, port->ring_cookies,
 444                          map_perm);
 445         if (err < 0) {
 446                 printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
 447                 return err;
 448         }
 449
 450         rqe = &port->rq_arr[dr->prod];
 451         rqe->req = req;
 452
 453         desc->hdr.ack = VIO_ACK_ENABLE;
 454         desc->req_id = port->req_id;
 455         desc->operation = op;
 456         if (port->vdisk_type == VD_DISK_TYPE_DISK) {
 457                 desc->slice = 0xff;
 458         } else {
 459                 desc->slice = 0;
 460         }
 461         desc->status = ~0;
 462         desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
 463         desc->size = len;
 464         desc->ncookies = err;
 465
 466         /* This has to be a non-SMP write barrier because we are writing
 467          * to memory which is shared with the peer LDOM.
 468          */
 469         wmb();
 470         desc->hdr.state = VIO_DESC_READY;
 471
 472         err = __vdc_tx_trigger(port);
 473         if (err < 0) {
 474                 printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
 475         } else {
 476                 port->req_id++;
 477                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
 478         }
 479
 480         return err;
 481 }
 482
 483 static void do_vdc_request(struct request_queue *rq)
 484 {
 485         struct request *req;
 486
 487         while ((req = blk_peek_request(rq)) != NULL) {
 488                 struct vdc_port *port;
 489                 struct vio_dring_state *dr;
 490
 491                 port = req->rq_disk->private_data;
 492                 dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 493                 if (unlikely(vdc_tx_dring_avail(dr) < 1))
 494                         goto wait;
 495
 496                 blk_start_request(req);
 497
 498                 if (__send_request(req) < 0) {
 499                         blk_requeue_request(rq, req);
 500 wait:
 501                         /* Avoid pointless unplugs. */
 502                         blk_stop_queue(rq);
 503                         break;
 504                 }
 505         }
 506 }
 507
 508 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
 509 {
 510         struct vio_dring_state *dr;
 511         struct vio_completion comp;
 512         struct vio_disk_desc *desc;
 513         unsigned int map_perm;
 514         unsigned long flags;
 515         int op_len, err;
 516         void *req_buf;
 517
 518         if (!(((u64)1 << (u64)op) & port->operations))
 519                 return -EOPNOTSUPP;
 520
 521         switch (op) {
 522         case VD_OP_BREAD:
 523         case VD_OP_BWRITE:
 524         default:
 525                 return -EINVAL;
 526
 527         case VD_OP_FLUSH:
 528                 op_len = 0;
 529                 map_perm = 0;
 530                 break;
 531
 532         case VD_OP_GET_WCE:
 533                 op_len = sizeof(u32);
 534                 map_perm = LDC_MAP_W;
 535                 break;
 536
 537         case VD_OP_SET_WCE:
 538                 op_len = sizeof(u32);
 539                 map_perm = LDC_MAP_R;
 540                 break;
 541
 542         case VD_OP_GET_VTOC:
 543                 op_len = sizeof(struct vio_disk_vtoc);
 544                 map_perm = LDC_MAP_W;
 545                 break;
 546
 547         case VD_OP_SET_VTOC:
 548                 op_len = sizeof(struct vio_disk_vtoc);
 549                 map_perm = LDC_MAP_R;
 550                 break;
 551
 552         case VD_OP_GET_DISKGEOM:
 553                 op_len = sizeof(struct vio_disk_geom);
 554                 map_perm = LDC_MAP_W;
 555                 break;
 556
 557         case VD_OP_SET_DISKGEOM:
 558                 op_len = sizeof(struct vio_disk_geom);
 559                 map_perm = LDC_MAP_R;
 560                 break;
 561
 562         case VD_OP_SCSICMD:
 563                 op_len = 16;
 564                 map_perm = LDC_MAP_RW;
 565                 break;
 566
 567         case VD_OP_GET_DEVID:
 568                 op_len = sizeof(struct vio_disk_devid);
 569                 map_perm = LDC_MAP_W;
 570                 break;
 571
 572         case VD_OP_GET_EFI:
 573         case VD_OP_SET_EFI:
 574                 return -EOPNOTSUPP;
 575                 break;
 576         };
 577
 578         map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 579
 580         op_len = (op_len + 7) & ~7;
 581         req_buf = kzalloc(op_len, GFP_KERNEL);
 582         if (!req_buf)
 583                 return -ENOMEM;
 584
 585         if (len > op_len)
 586                 len = op_len;
 587
 588         if (map_perm & LDC_MAP_R)
 589                 memcpy(req_buf, buf, len);
 590
 591         spin_lock_irqsave(&port->vio.lock, flags);
 592
 593         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 594
 595         /* XXX If we want to use this code generically we have to
 596          * XXX handle TX ring exhaustion etc.
 597          */
 598         desc = vio_dring_cur(dr);
 599
 600         err = ldc_map_single(port->vio.lp, req_buf, op_len,
 601                              desc->cookies, port->ring_cookies,
 602                              map_perm);
 603         if (err < 0) {
 604                 spin_unlock_irqrestore(&port->vio.lock, flags);
 605                 kfree(req_buf);
 606                 return err;
 607         }
 608
 609         init_completion(&comp.com);
 610         comp.waiting_for = WAITING_FOR_GEN_CMD;
 611         port->vio.cmp = &comp;
 612
 613         desc->hdr.ack = VIO_ACK_ENABLE;
 614         desc->req_id = port->req_id;
 615         desc->operation = op;
 616         desc->slice = 0;
 617         desc->status = ~0;
 618         desc->offset = 0;
 619         desc->size = op_len;
 620         desc->ncookies = err;
 621
 622         /* This has to be a non-SMP write barrier because we are writing
 623          * to memory which is shared with the peer LDOM.
 624          */
 625         wmb();
 626         desc->hdr.state = VIO_DESC_READY;
 627
 628         err = __vdc_tx_trigger(port);
 629         if (err >= 0) {
 630                 port->req_id++;
 631                 dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1);
 632                 spin_unlock_irqrestore(&port->vio.lock, flags);
 633
 634                 wait_for_completion(&comp.com);
 635                 err = comp.err;
 636         } else {
 637                 port->vio.cmp = NULL;
 638                 spin_unlock_irqrestore(&port->vio.lock, flags);
 639         }
 640
 641         if (map_perm & LDC_MAP_W)
 642                 memcpy(buf, req_buf, len);
 643
 644         kfree(req_buf);
 645
 646         return err;
 647 }
 648
 649 static int vdc_alloc_tx_ring(struct vdc_port *port)
 650 {
 651         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 652         unsigned long len, entry_size;
 653         int ncookies;
 654         void *dring;
 655
 656         entry_size = sizeof(struct vio_disk_desc) +
 657                 (sizeof(struct ldc_trans_cookie) * port->ring_cookies);
 658         len = (VDC_TX_RING_SIZE * entry_size);
 659
 660         ncookies = VIO_MAX_RING_COOKIES;
 661         dring = ldc_alloc_exp_dring(port->vio.lp, len,
 662                                     dr->cookies, &ncookies,
 663                                     (LDC_MAP_SHADOW |
 664                                      LDC_MAP_DIRECT |
 665                                      LDC_MAP_RW));
 666         if (IS_ERR(dring))
 667                 return PTR_ERR(dring);
 668
 669         dr->base = dring;
 670         dr->entry_size = entry_size;
 671         dr->num_entries = VDC_TX_RING_SIZE;
 672         dr->prod = dr->cons = 0;
 673         dr->pending = VDC_TX_RING_SIZE;
 674         dr->ncookies = ncookies;
 675
 676         return 0;
 677 }
 678
 679 static void vdc_free_tx_ring(struct vdc_port *port)
 680 {
 681         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 682
 683         if (dr->base) {
 684                 ldc_free_exp_dring(port->vio.lp, dr->base,
 685                                    (dr->entry_size * dr->num_entries),
 686                                    dr->cookies, dr->ncookies);
 687                 dr->base = NULL;
 688                 dr->entry_size = 0;
 689                 dr->num_entries = 0;
 690                 dr->pending = 0;
 691                 dr->ncookies = 0;
 692         }
 693 }
 694
 695 static int probe_disk(struct vdc_port *port)
 696 {
 697         struct vio_completion comp;
 698         struct request_queue *q;
 699         struct gendisk *g;
 700         int err;
 701
 702         init_completion(&comp.com);
 703         comp.err = 0;
 704         comp.waiting_for = WAITING_FOR_LINK_UP;
 705         port->vio.cmp = &comp;
 706
 707         vio_port_up(&port->vio);
 708
 709         wait_for_completion(&comp.com);
 710         if (comp.err)
 711                 return comp.err;
 712
 713         err = generic_request(port, VD_OP_GET_VTOC,
 714                               &port->label, sizeof(port->label));
 715         if (err < 0) {
 716                 printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err);
 717                 return err;
 718         }
 719
 720         if (vdc_version_supported(port, 1, 1)) {
 721                 /* vdisk_size should be set during the handshake, if it wasn't
 722                  * then the underlying disk is reserved by another system
 723                  */
 724                 if (port->vdisk_size == -1)
 725                         return -ENODEV;
 726         } else {
 727                 struct vio_disk_geom geom;
 728
 729                 err = generic_request(port, VD_OP_GET_DISKGEOM,
 730                                       &geom, sizeof(geom));
 731                 if (err < 0) {
 732                         printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
 733                                "error %d\n", err);
 734                         return err;
 735                 }
 736                 port->vdisk_size = ((u64)geom.num_cyl *
 737                                     (u64)geom.num_hd *
 738                                     (u64)geom.num_sec);
 739         }
 740
 741         q = blk_init_queue(do_vdc_request, &port->vio.lock);
 742         if (!q) {
 743                 printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
 744                        port->vio.name);
 745                 return -ENOMEM;
 746         }
 747         g = alloc_disk(1 << PARTITION_SHIFT);
 748         if (!g) {
 749                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
 750                        port->vio.name);
 751                 blk_cleanup_queue(q);
 752                 return -ENOMEM;
 753         }
 754
 755         port->disk = g;
 756
 757         /* Each segment in a request is up to an aligned page in size. */
 758         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
 759         blk_queue_max_segment_size(q, PAGE_SIZE);
 760
 761         blk_queue_max_segments(q, port->ring_cookies);
 762         blk_queue_max_hw_sectors(q, port->max_xfer_size);
 763         g->major = vdc_major;
 764         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
 765         strcpy(g->disk_name, port->disk_name);
 766
 767         g->fops = &vdc_fops;
 768         g->queue = q;
 769         g->private_data = port;
 770         g->driverfs_dev = &port->vio.vdev->dev;
 771
 772         set_capacity(g, port->vdisk_size);
 773
 774         if (vdc_version_supported(port, 1, 1)) {
 775                 switch (port->vdisk_mtype) {
 776                 case VD_MEDIA_TYPE_CD:
 777                         pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
 778                         g->flags |= GENHD_FL_CD;
 779                         g->flags |= GENHD_FL_REMOVABLE;
 780                         set_disk_ro(g, 1);
 781                         break;
 782
 783                 case VD_MEDIA_TYPE_DVD:
 784                         pr_info(PFX "Virtual DVD %s\n", port->disk_name);
 785                         g->flags |= GENHD_FL_CD;
 786                         g->flags |= GENHD_FL_REMOVABLE;
 787                         set_disk_ro(g, 1);
 788                         break;
 789
 790                 case VD_MEDIA_TYPE_FIXED:
 791                         pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
 792                         break;
 793                 }
 794         }
 795
 796         pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
 797                g->disk_name,
 798                port->vdisk_size, (port->vdisk_size >> (20 - 9)),
 799                port->vio.ver.major, port->vio.ver.minor);
 800
 801         add_disk(g);
 802
 803         return 0;
 804 }
 805
 806 static struct ldc_channel_config vdc_ldc_cfg = {
 807         .event          = vdc_event,
 808         .mtu            = 64,
 809         .mode           = LDC_MODE_UNRELIABLE,
 810 };
 811
 812 static struct vio_driver_ops vdc_vio_ops = {
 813         .send_attr              = vdc_send_attr,
 814         .handle_attr            = vdc_handle_attr,
 815         .handshake_complete     = vdc_handshake_complete,
 816 };
 817
 818 static void print_version(void)
 819 {
 820         static int version_printed;
 821
 822         if (version_printed++ == 0)
 823                 printk(KERN_INFO "%s", version);
 824 }
 825
 826 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 827 {
 828         struct mdesc_handle *hp;
 829         struct vdc_port *port;
 830         int err;
 831
 832         print_version();
 833
 834         hp = mdesc_grab();
 835
 836         err = -ENODEV;
 837         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
 838                 printk(KERN_ERR PFX "Port id [%llu] too large.\n",
 839                        vdev->dev_no);
 840                 goto err_out_release_mdesc;
 841         }
 842
 843         port = kzalloc(sizeof(*port), GFP_KERNEL);
 844         err = -ENOMEM;
 845         if (!port) {
 846                 printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
 847                 goto err_out_release_mdesc;
 848         }
 849
 850         if (vdev->dev_no >= 26)
 851                 snprintf(port->disk_name, sizeof(port->disk_name),
 852                          VDCBLK_NAME "%c%c",
 853                          'a' + ((int)vdev->dev_no / 26) - 1,
 854                          'a' + ((int)vdev->dev_no % 26));
 855         else
 856                 snprintf(port->disk_name, sizeof(port->disk_name),
 857                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
 858         port->vdisk_size = -1;
 859
 860         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
 861                               vdc_versions, ARRAY_SIZE(vdc_versions),
 862                               &vdc_vio_ops, port->disk_name);
 863         if (err)
 864                 goto err_out_free_port;
 865
 866         port->vdisk_block_size = 512;
 867         port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
 868         port->ring_cookies = ((port->max_xfer_size *
 869                                port->vdisk_block_size) / PAGE_SIZE) + 2;
 870
 871         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
 872         if (err)
 873                 goto err_out_free_port;
 874
 875         err = vdc_alloc_tx_ring(port);
 876         if (err)
 877                 goto err_out_free_ldc;
 878
 879         err = probe_disk(port);
 880         if (err)
 881                 goto err_out_free_tx_ring;
 882
 883         dev_set_drvdata(&vdev->dev, port);
 884
 885         mdesc_release(hp);
 886
 887         return 0;
 888
 889 err_out_free_tx_ring:
 890         vdc_free_tx_ring(port);
 891
 892 err_out_free_ldc:
 893         vio_ldc_free(&port->vio);
 894
 895 err_out_free_port:
 896         kfree(port);
 897
 898 err_out_release_mdesc:
 899         mdesc_release(hp);
 900         return err;
 901 }
 902
 903 static int vdc_port_remove(struct vio_dev *vdev)
 904 {
 905         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
 906
 907         if (port) {
 908                 del_timer_sync(&port->vio.timer);
 909
 910                 vdc_free_tx_ring(port);
 911                 vio_ldc_free(&port->vio);
 912
 913                 dev_set_drvdata(&vdev->dev, NULL);
 914
 915                 kfree(port);
 916         }
 917         return 0;
 918 }
 919
 920 static const struct vio_device_id vdc_port_match[] = {
 921         {
 922                 .type = "vdc-port",
 923         },
 924         {},
 925 };
 926 MODULE_DEVICE_TABLE(vio, vdc_port_match);
 927
 928 static struct vio_driver vdc_port_driver = {
 929         .id_table       = vdc_port_match,
 930         .probe          = vdc_port_probe,
 931         .remove         = vdc_port_remove,
 932         .name           = "vdc_port",
 933 };
 934
 935 static int __init vdc_init(void)
 936 {
 937         int err;
 938
 939         err = register_blkdev(0, VDCBLK_NAME);
 940         if (err < 0)
 941                 goto out_err;
 942
 943         vdc_major = err;
 944
 945         err = vio_register_driver(&vdc_port_driver);
 946         if (err)
 947                 goto out_unregister_blkdev;
 948
 949         return 0;
 950
 951 out_unregister_blkdev:
 952         unregister_blkdev(vdc_major, VDCBLK_NAME);
 953         vdc_major = 0;
 954
 955 out_err:
 956         return err;
 957 }
 958
 959 static void __exit vdc_exit(void)
 960 {
 961         vio_unregister_driver(&vdc_port_driver);
 962         unregister_blkdev(vdc_major, VDCBLK_NAME);
 963 }
 964
 965 module_init(vdc_init);
 966 module_exit(vdc_exit);