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      "1.2"
  27 #define DRV_MODULE_RELDATE      "November 24, 2014"
  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 static struct workqueue_struct *sunvdc_wq;
  44
  45 struct vdc_req_entry {
  46         struct request          *req;
  47 };
  48
  49 struct vdc_port {
  50         struct vio_driver_state vio;
  51
  52         struct gendisk          *disk;
  53
  54         struct vdc_completion   *cmp;
  55
  56         u64                     req_id;
  57         u64                     seq;
  58         struct vdc_req_entry    rq_arr[VDC_TX_RING_SIZE];
  59
  60         unsigned long           ring_cookies;
  61
  62         u64                     max_xfer_size;
  63         u32                     vdisk_block_size;
  64
  65         u64                     ldc_timeout;
  66         struct timer_list       ldc_reset_timer;
  67         struct work_struct      ldc_reset_work;
  68
  69         /* The server fills these in for us in the disk attribute
  70          * ACK packet.
  71          */
  72         u64                     operations;
  73         u32                     vdisk_size;
  74         u8                      vdisk_type;
  75         u8                      vdisk_mtype;
  76
  77         char                    disk_name[32];
  78 };
  79
  80 static void vdc_ldc_reset(struct vdc_port *port);
  81 static void vdc_ldc_reset_work(struct work_struct *work);
  82 static void vdc_ldc_reset_timer(unsigned long _arg);
  83
  84 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
  85 {
  86         return container_of(vio, struct vdc_port, vio);
  87 }
  88
  89 /* Ordered from largest major to lowest */
  90 static struct vio_version vdc_versions[] = {
  91         { .major = 1, .minor = 1 },
  92         { .major = 1, .minor = 0 },
  93 };
  94
  95 static inline int vdc_version_supported(struct vdc_port *port,
  96                                         u16 major, u16 minor)
  97 {
  98         return port->vio.ver.major == major && port->vio.ver.minor >= minor;
  99 }
 100
 101 #define VDCBLK_NAME     "vdisk"
 102 static int vdc_major;
 103 #define PARTITION_SHIFT 3
 104
 105 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
 106 {
 107         return vio_dring_avail(dr, VDC_TX_RING_SIZE);
 108 }
 109
 110 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 111 {
 112         struct gendisk *disk = bdev->bd_disk;
 113         sector_t nsect = get_capacity(disk);
 114         sector_t cylinders = nsect;
 115
 116         geo->heads = 0xff;
 117         geo->sectors = 0x3f;
 118         sector_div(cylinders, geo->heads * geo->sectors);
 119         geo->cylinders = cylinders;
 120         if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
 121                 geo->cylinders = 0xffff;
 122
 123         return 0;
 124 }
 125
 126 /* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
 127  * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
 128  * Needed to be able to install inside an ldom from an iso image.
 129  */
 130 static int vdc_ioctl(struct block_device *bdev, fmode_t mode,
 131                      unsigned command, unsigned long argument)
 132 {
 133         int i;
 134         struct gendisk *disk;
 135
 136         switch (command) {
 137         case CDROMMULTISESSION:
 138                 pr_debug(PFX "Multisession CDs not supported\n");
 139                 for (i = 0; i < sizeof(struct cdrom_multisession); i++)
 140                         if (put_user(0, (char __user *)(argument + i)))
 141                                 return -EFAULT;
 142                 return 0;
 143
 144         case CDROM_GET_CAPABILITY:
 145                 disk = bdev->bd_disk;
 146
 147                 if (bdev->bd_disk && (disk->flags & GENHD_FL_CD))
 148                         return 0;
 149                 return -EINVAL;
 150
 151         default:
 152                 pr_debug(PFX "ioctl %08x not supported\n", command);
 153                 return -EINVAL;
 154         }
 155 }
 156
 157 static const struct block_device_operations vdc_fops = {
 158         .owner          = THIS_MODULE,
 159         .getgeo         = vdc_getgeo,
 160         .ioctl          = vdc_ioctl,
 161 };
 162
 163 static void vdc_blk_queue_start(struct vdc_port *port)
 164 {
 165         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 166
 167         /* restart blk queue when ring is half emptied. also called after
 168          * handshake completes, so check for initial handshake before we've
 169          * allocated a disk.
 170          */
 171         if (port->disk && blk_queue_stopped(port->disk->queue) &&
 172             vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50) {
 173                 blk_start_queue(port->disk->queue);
 174         }
 175
 176 }
 177
 178 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
 179 {
 180         if (vio->cmp &&
 181             (waiting_for == -1 ||
 182              vio->cmp->waiting_for == waiting_for)) {
 183                 vio->cmp->err = err;
 184                 complete(&vio->cmp->com);
 185                 vio->cmp = NULL;
 186         }
 187 }
 188
 189 static void vdc_handshake_complete(struct vio_driver_state *vio)
 190 {
 191         struct vdc_port *port = to_vdc_port(vio);
 192
 193         del_timer(&port->ldc_reset_timer);
 194         vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
 195         vdc_blk_queue_start(port);
 196 }
 197
 198 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
 199 {
 200         struct vio_msg_tag *pkt = arg;
 201
 202         printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
 203                pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
 204         printk(KERN_ERR PFX "Resetting connection.\n");
 205
 206         ldc_disconnect(port->vio.lp);
 207
 208         return -ECONNRESET;
 209 }
 210
 211 static int vdc_send_attr(struct vio_driver_state *vio)
 212 {
 213         struct vdc_port *port = to_vdc_port(vio);
 214         struct vio_disk_attr_info pkt;
 215
 216         memset(&pkt, 0, sizeof(pkt));
 217
 218         pkt.tag.type = VIO_TYPE_CTRL;
 219         pkt.tag.stype = VIO_SUBTYPE_INFO;
 220         pkt.tag.stype_env = VIO_ATTR_INFO;
 221         pkt.tag.sid = vio_send_sid(vio);
 222
 223         pkt.xfer_mode = VIO_DRING_MODE;
 224         pkt.vdisk_block_size = port->vdisk_block_size;
 225         pkt.max_xfer_size = port->max_xfer_size;
 226
 227         viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 228                pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
 229
 230         return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
 231 }
 232
 233 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
 234 {
 235         struct vdc_port *port = to_vdc_port(vio);
 236         struct vio_disk_attr_info *pkt = arg;
 237
 238         viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
 239                "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 240                pkt->tag.stype, pkt->operations,
 241                pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
 242                pkt->xfer_mode, pkt->vdisk_block_size,
 243                pkt->max_xfer_size);
 244
 245         if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
 246                 switch (pkt->vdisk_type) {
 247                 case VD_DISK_TYPE_DISK:
 248                 case VD_DISK_TYPE_SLICE:
 249                         break;
 250
 251                 default:
 252                         printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
 253                                vio->name, pkt->vdisk_type);
 254                         return -ECONNRESET;
 255                 }
 256
 257                 if (pkt->vdisk_block_size > port->vdisk_block_size) {
 258                         printk(KERN_ERR PFX "%s: BLOCK size increased "
 259                                "%u --> %u\n",
 260                                vio->name,
 261                                port->vdisk_block_size, pkt->vdisk_block_size);
 262                         return -ECONNRESET;
 263                 }
 264
 265                 port->operations = pkt->operations;
 266                 port->vdisk_type = pkt->vdisk_type;
 267                 if (vdc_version_supported(port, 1, 1)) {
 268                         port->vdisk_size = pkt->vdisk_size;
 269                         port->vdisk_mtype = pkt->vdisk_mtype;
 270                 }
 271                 if (pkt->max_xfer_size < port->max_xfer_size)
 272                         port->max_xfer_size = pkt->max_xfer_size;
 273                 port->vdisk_block_size = pkt->vdisk_block_size;
 274                 return 0;
 275         } else {
 276                 printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
 277
 278                 return -ECONNRESET;
 279         }
 280 }
 281
 282 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
 283 {
 284         int err = desc->status;
 285
 286         vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
 287 }
 288
 289 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
 290                         unsigned int index)
 291 {
 292         struct vio_disk_desc *desc = vio_dring_entry(dr, index);
 293         struct vdc_req_entry *rqe = &port->rq_arr[index];
 294         struct request *req;
 295
 296         if (unlikely(desc->hdr.state != VIO_DESC_DONE))
 297                 return;
 298
 299         ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
 300         desc->hdr.state = VIO_DESC_FREE;
 301         dr->cons = vio_dring_next(dr, index);
 302
 303         req = rqe->req;
 304         if (req == NULL) {
 305                 vdc_end_special(port, desc);
 306                 return;
 307         }
 308
 309         rqe->req = NULL;
 310
 311         __blk_end_request(req, (desc->status ? -EIO : 0), desc->size);
 312
 313         vdc_blk_queue_start(port);
 314 }
 315
 316 static int vdc_ack(struct vdc_port *port, void *msgbuf)
 317 {
 318         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 319         struct vio_dring_data *pkt = msgbuf;
 320
 321         if (unlikely(pkt->dring_ident != dr->ident ||
 322                      pkt->start_idx != pkt->end_idx ||
 323                      pkt->start_idx >= VDC_TX_RING_SIZE))
 324                 return 0;
 325
 326         vdc_end_one(port, dr, pkt->start_idx);
 327
 328         return 0;
 329 }
 330
 331 static int vdc_nack(struct vdc_port *port, void *msgbuf)
 332 {
 333         /* XXX Implement me XXX */
 334         return 0;
 335 }
 336
 337 static void vdc_event(void *arg, int event)
 338 {
 339         struct vdc_port *port = arg;
 340         struct vio_driver_state *vio = &port->vio;
 341         unsigned long flags;
 342         int err;
 343
 344         spin_lock_irqsave(&vio->lock, flags);
 345
 346         if (unlikely(event == LDC_EVENT_RESET)) {
 347                 vio_link_state_change(vio, event);
 348                 queue_work(sunvdc_wq, &port->ldc_reset_work);
 349                 goto out;
 350         }
 351
 352         if (unlikely(event == LDC_EVENT_UP)) {
 353                 vio_link_state_change(vio, event);
 354                 goto out;
 355         }
 356
 357         if (unlikely(event != LDC_EVENT_DATA_READY)) {
 358                 pr_warn(PFX "Unexpected LDC event %d\n", event);
 359                 goto out;
 360         }
 361
 362         err = 0;
 363         while (1) {
 364                 union {
 365                         struct vio_msg_tag tag;
 366                         u64 raw[8];
 367                 } msgbuf;
 368
 369                 err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
 370                 if (unlikely(err < 0)) {
 371                         if (err == -ECONNRESET)
 372                                 vio_conn_reset(vio);
 373                         break;
 374                 }
 375                 if (err == 0)
 376                         break;
 377                 viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
 378                        msgbuf.tag.type,
 379                        msgbuf.tag.stype,
 380                        msgbuf.tag.stype_env,
 381                        msgbuf.tag.sid);
 382                 err = vio_validate_sid(vio, &msgbuf.tag);
 383                 if (err < 0)
 384                         break;
 385
 386                 if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
 387                         if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
 388                                 err = vdc_ack(port, &msgbuf);
 389                         else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
 390                                 err = vdc_nack(port, &msgbuf);
 391                         else
 392                                 err = vdc_handle_unknown(port, &msgbuf);
 393                 } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
 394                         err = vio_control_pkt_engine(vio, &msgbuf);
 395                 } else {
 396                         err = vdc_handle_unknown(port, &msgbuf);
 397                 }
 398                 if (err < 0)
 399                         break;
 400         }
 401         if (err < 0)
 402                 vdc_finish(&port->vio, err, WAITING_FOR_ANY);
 403 out:
 404         spin_unlock_irqrestore(&vio->lock, flags);
 405 }
 406
 407 static int __vdc_tx_trigger(struct vdc_port *port)
 408 {
 409         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 410         struct vio_dring_data hdr = {
 411                 .tag = {
 412                         .type           = VIO_TYPE_DATA,
 413                         .stype          = VIO_SUBTYPE_INFO,
 414                         .stype_env      = VIO_DRING_DATA,
 415                         .sid            = vio_send_sid(&port->vio),
 416                 },
 417                 .dring_ident            = dr->ident,
 418                 .start_idx              = dr->prod,
 419                 .end_idx                = dr->prod,
 420         };
 421         int err, delay;
 422
 423         hdr.seq = dr->snd_nxt;
 424         delay = 1;
 425         do {
 426                 err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
 427                 if (err > 0) {
 428                         dr->snd_nxt++;
 429                         break;
 430                 }
 431                 udelay(delay);
 432                 if ((delay <<= 1) > 128)
 433                         delay = 128;
 434         } while (err == -EAGAIN);
 435
 436         if (err == -ENOTCONN)
 437                 vdc_ldc_reset(port);
 438         return err;
 439 }
 440
 441 static int __send_request(struct request *req)
 442 {
 443         struct vdc_port *port = req->rq_disk->private_data;
 444         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 445         struct scatterlist sg[port->ring_cookies];
 446         struct vdc_req_entry *rqe;
 447         struct vio_disk_desc *desc;
 448         unsigned int map_perm;
 449         int nsg, err, i;
 450         u64 len;
 451         u8 op;
 452
 453         map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 454
 455         if (rq_data_dir(req) == READ) {
 456                 map_perm |= LDC_MAP_W;
 457                 op = VD_OP_BREAD;
 458         } else {
 459                 map_perm |= LDC_MAP_R;
 460                 op = VD_OP_BWRITE;
 461         }
 462
 463         sg_init_table(sg, port->ring_cookies);
 464         nsg = blk_rq_map_sg(req->q, req, sg);
 465
 466         len = 0;
 467         for (i = 0; i < nsg; i++)
 468                 len += sg[i].length;
 469
 470         desc = vio_dring_cur(dr);
 471
 472         err = ldc_map_sg(port->vio.lp, sg, nsg,
 473                          desc->cookies, port->ring_cookies,
 474                          map_perm);
 475         if (err < 0) {
 476                 printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
 477                 return err;
 478         }
 479
 480         rqe = &port->rq_arr[dr->prod];
 481         rqe->req = req;
 482
 483         desc->hdr.ack = VIO_ACK_ENABLE;
 484         desc->req_id = port->req_id;
 485         desc->operation = op;
 486         if (port->vdisk_type == VD_DISK_TYPE_DISK) {
 487                 desc->slice = 0xff;
 488         } else {
 489                 desc->slice = 0;
 490         }
 491         desc->status = ~0;
 492         desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
 493         desc->size = len;
 494         desc->ncookies = err;
 495
 496         /* This has to be a non-SMP write barrier because we are writing
 497          * to memory which is shared with the peer LDOM.
 498          */
 499         wmb();
 500         desc->hdr.state = VIO_DESC_READY;
 501
 502         err = __vdc_tx_trigger(port);
 503         if (err < 0) {
 504                 printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
 505         } else {
 506                 port->req_id++;
 507                 dr->prod = vio_dring_next(dr, dr->prod);
 508         }
 509
 510         return err;
 511 }
 512
 513 static void do_vdc_request(struct request_queue *rq)
 514 {
 515         struct request *req;
 516
 517         while ((req = blk_peek_request(rq)) != NULL) {
 518                 struct vdc_port *port;
 519                 struct vio_dring_state *dr;
 520
 521                 port = req->rq_disk->private_data;
 522                 dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 523                 if (unlikely(vdc_tx_dring_avail(dr) < 1))
 524                         goto wait;
 525
 526                 blk_start_request(req);
 527
 528                 if (__send_request(req) < 0) {
 529                         blk_requeue_request(rq, req);
 530 wait:
 531                         /* Avoid pointless unplugs. */
 532                         blk_stop_queue(rq);
 533                         break;
 534                 }
 535         }
 536 }
 537
 538 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
 539 {
 540         struct vio_dring_state *dr;
 541         struct vio_completion comp;
 542         struct vio_disk_desc *desc;
 543         unsigned int map_perm;
 544         unsigned long flags;
 545         int op_len, err;
 546         void *req_buf;
 547
 548         if (!(((u64)1 << (u64)op) & port->operations))
 549                 return -EOPNOTSUPP;
 550
 551         switch (op) {
 552         case VD_OP_BREAD:
 553         case VD_OP_BWRITE:
 554         default:
 555                 return -EINVAL;
 556
 557         case VD_OP_FLUSH:
 558                 op_len = 0;
 559                 map_perm = 0;
 560                 break;
 561
 562         case VD_OP_GET_WCE:
 563                 op_len = sizeof(u32);
 564                 map_perm = LDC_MAP_W;
 565                 break;
 566
 567         case VD_OP_SET_WCE:
 568                 op_len = sizeof(u32);
 569                 map_perm = LDC_MAP_R;
 570                 break;
 571
 572         case VD_OP_GET_VTOC:
 573                 op_len = sizeof(struct vio_disk_vtoc);
 574                 map_perm = LDC_MAP_W;
 575                 break;
 576
 577         case VD_OP_SET_VTOC:
 578                 op_len = sizeof(struct vio_disk_vtoc);
 579                 map_perm = LDC_MAP_R;
 580                 break;
 581
 582         case VD_OP_GET_DISKGEOM:
 583                 op_len = sizeof(struct vio_disk_geom);
 584                 map_perm = LDC_MAP_W;
 585                 break;
 586
 587         case VD_OP_SET_DISKGEOM:
 588                 op_len = sizeof(struct vio_disk_geom);
 589                 map_perm = LDC_MAP_R;
 590                 break;
 591
 592         case VD_OP_SCSICMD:
 593                 op_len = 16;
 594                 map_perm = LDC_MAP_RW;
 595                 break;
 596
 597         case VD_OP_GET_DEVID:
 598                 op_len = sizeof(struct vio_disk_devid);
 599                 map_perm = LDC_MAP_W;
 600                 break;
 601
 602         case VD_OP_GET_EFI:
 603         case VD_OP_SET_EFI:
 604                 return -EOPNOTSUPP;
 605                 break;
 606         };
 607
 608         map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 609
 610         op_len = (op_len + 7) & ~7;
 611         req_buf = kzalloc(op_len, GFP_KERNEL);
 612         if (!req_buf)
 613                 return -ENOMEM;
 614
 615         if (len > op_len)
 616                 len = op_len;
 617
 618         if (map_perm & LDC_MAP_R)
 619                 memcpy(req_buf, buf, len);
 620
 621         spin_lock_irqsave(&port->vio.lock, flags);
 622
 623         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 624
 625         /* XXX If we want to use this code generically we have to
 626          * XXX handle TX ring exhaustion etc.
 627          */
 628         desc = vio_dring_cur(dr);
 629
 630         err = ldc_map_single(port->vio.lp, req_buf, op_len,
 631                              desc->cookies, port->ring_cookies,
 632                              map_perm);
 633         if (err < 0) {
 634                 spin_unlock_irqrestore(&port->vio.lock, flags);
 635                 kfree(req_buf);
 636                 return err;
 637         }
 638
 639         init_completion(&comp.com);
 640         comp.waiting_for = WAITING_FOR_GEN_CMD;
 641         port->vio.cmp = &comp;
 642
 643         desc->hdr.ack = VIO_ACK_ENABLE;
 644         desc->req_id = port->req_id;
 645         desc->operation = op;
 646         desc->slice = 0;
 647         desc->status = ~0;
 648         desc->offset = 0;
 649         desc->size = op_len;
 650         desc->ncookies = err;
 651
 652         /* This has to be a non-SMP write barrier because we are writing
 653          * to memory which is shared with the peer LDOM.
 654          */
 655         wmb();
 656         desc->hdr.state = VIO_DESC_READY;
 657
 658         err = __vdc_tx_trigger(port);
 659         if (err >= 0) {
 660                 port->req_id++;
 661                 dr->prod = vio_dring_next(dr, dr->prod);
 662                 spin_unlock_irqrestore(&port->vio.lock, flags);
 663
 664                 wait_for_completion(&comp.com);
 665                 err = comp.err;
 666         } else {
 667                 port->vio.cmp = NULL;
 668                 spin_unlock_irqrestore(&port->vio.lock, flags);
 669         }
 670
 671         if (map_perm & LDC_MAP_W)
 672                 memcpy(buf, req_buf, len);
 673
 674         kfree(req_buf);
 675
 676         return err;
 677 }
 678
 679 static int vdc_alloc_tx_ring(struct vdc_port *port)
 680 {
 681         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 682         unsigned long len, entry_size;
 683         int ncookies;
 684         void *dring;
 685
 686         entry_size = sizeof(struct vio_disk_desc) +
 687                 (sizeof(struct ldc_trans_cookie) * port->ring_cookies);
 688         len = (VDC_TX_RING_SIZE * entry_size);
 689
 690         ncookies = VIO_MAX_RING_COOKIES;
 691         dring = ldc_alloc_exp_dring(port->vio.lp, len,
 692                                     dr->cookies, &ncookies,
 693                                     (LDC_MAP_SHADOW |
 694                                      LDC_MAP_DIRECT |
 695                                      LDC_MAP_RW));
 696         if (IS_ERR(dring))
 697                 return PTR_ERR(dring);
 698
 699         dr->base = dring;
 700         dr->entry_size = entry_size;
 701         dr->num_entries = VDC_TX_RING_SIZE;
 702         dr->prod = dr->cons = 0;
 703         dr->pending = VDC_TX_RING_SIZE;
 704         dr->ncookies = ncookies;
 705
 706         return 0;
 707 }
 708
 709 static void vdc_free_tx_ring(struct vdc_port *port)
 710 {
 711         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 712
 713         if (dr->base) {
 714                 ldc_free_exp_dring(port->vio.lp, dr->base,
 715                                    (dr->entry_size * dr->num_entries),
 716                                    dr->cookies, dr->ncookies);
 717                 dr->base = NULL;
 718                 dr->entry_size = 0;
 719                 dr->num_entries = 0;
 720                 dr->pending = 0;
 721                 dr->ncookies = 0;
 722         }
 723 }
 724
 725 static int vdc_port_up(struct vdc_port *port)
 726 {
 727         struct vio_completion comp;
 728
 729         init_completion(&comp.com);
 730         comp.err = 0;
 731         comp.waiting_for = WAITING_FOR_LINK_UP;
 732         port->vio.cmp = &comp;
 733
 734         vio_port_up(&port->vio);
 735         wait_for_completion(&comp.com);
 736         return comp.err;
 737 }
 738
 739 static void vdc_port_down(struct vdc_port *port)
 740 {
 741         ldc_disconnect(port->vio.lp);
 742         ldc_unbind(port->vio.lp);
 743         vdc_free_tx_ring(port);
 744         vio_ldc_free(&port->vio);
 745 }
 746
 747 static int probe_disk(struct vdc_port *port)
 748 {
 749         struct request_queue *q;
 750         struct gendisk *g;
 751         int err;
 752
 753         err = vdc_port_up(port);
 754         if (err)
 755                 return err;
 756
 757         if (vdc_version_supported(port, 1, 1)) {
 758                 /* vdisk_size should be set during the handshake, if it wasn't
 759                  * then the underlying disk is reserved by another system
 760                  */
 761                 if (port->vdisk_size == -1)
 762                         return -ENODEV;
 763         } else {
 764                 struct vio_disk_geom geom;
 765
 766                 err = generic_request(port, VD_OP_GET_DISKGEOM,
 767                                       &geom, sizeof(geom));
 768                 if (err < 0) {
 769                         printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
 770                                "error %d\n", err);
 771                         return err;
 772                 }
 773                 port->vdisk_size = ((u64)geom.num_cyl *
 774                                     (u64)geom.num_hd *
 775                                     (u64)geom.num_sec);
 776         }
 777
 778         q = blk_init_queue(do_vdc_request, &port->vio.lock);
 779         if (!q) {
 780                 printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
 781                        port->vio.name);
 782                 return -ENOMEM;
 783         }
 784         g = alloc_disk(1 << PARTITION_SHIFT);
 785         if (!g) {
 786                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
 787                        port->vio.name);
 788                 blk_cleanup_queue(q);
 789                 return -ENOMEM;
 790         }
 791
 792         port->disk = g;
 793
 794         /* Each segment in a request is up to an aligned page in size. */
 795         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
 796         blk_queue_max_segment_size(q, PAGE_SIZE);
 797
 798         blk_queue_max_segments(q, port->ring_cookies);
 799         blk_queue_max_hw_sectors(q, port->max_xfer_size);
 800         g->major = vdc_major;
 801         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
 802         strcpy(g->disk_name, port->disk_name);
 803
 804         g->fops = &vdc_fops;
 805         g->queue = q;
 806         g->private_data = port;
 807
 808         set_capacity(g, port->vdisk_size);
 809
 810         if (vdc_version_supported(port, 1, 1)) {
 811                 switch (port->vdisk_mtype) {
 812                 case VD_MEDIA_TYPE_CD:
 813                         pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
 814                         g->flags |= GENHD_FL_CD;
 815                         g->flags |= GENHD_FL_REMOVABLE;
 816                         set_disk_ro(g, 1);
 817                         break;
 818
 819                 case VD_MEDIA_TYPE_DVD:
 820                         pr_info(PFX "Virtual DVD %s\n", port->disk_name);
 821                         g->flags |= GENHD_FL_CD;
 822                         g->flags |= GENHD_FL_REMOVABLE;
 823                         set_disk_ro(g, 1);
 824                         break;
 825
 826                 case VD_MEDIA_TYPE_FIXED:
 827                         pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
 828                         break;
 829                 }
 830         }
 831
 832         pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
 833                g->disk_name,
 834                port->vdisk_size, (port->vdisk_size >> (20 - 9)),
 835                port->vio.ver.major, port->vio.ver.minor);
 836
 837         device_add_disk(&port->vio.vdev->dev, g);
 838
 839         return 0;
 840 }
 841
 842 static struct ldc_channel_config vdc_ldc_cfg = {
 843         .event          = vdc_event,
 844         .mtu            = 64,
 845         .mode           = LDC_MODE_UNRELIABLE,
 846 };
 847
 848 static struct vio_driver_ops vdc_vio_ops = {
 849         .send_attr              = vdc_send_attr,
 850         .handle_attr            = vdc_handle_attr,
 851         .handshake_complete     = vdc_handshake_complete,
 852 };
 853
 854 static void print_version(void)
 855 {
 856         static int version_printed;
 857
 858         if (version_printed++ == 0)
 859                 printk(KERN_INFO "%s", version);
 860 }
 861
 862 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 863 {
 864         struct mdesc_handle *hp;
 865         struct vdc_port *port;
 866         int err;
 867         const u64 *ldc_timeout;
 868
 869         print_version();
 870
 871         hp = mdesc_grab();
 872
 873         err = -ENODEV;
 874         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
 875                 printk(KERN_ERR PFX "Port id [%llu] too large.\n",
 876                        vdev->dev_no);
 877                 goto err_out_release_mdesc;
 878         }
 879
 880         port = kzalloc(sizeof(*port), GFP_KERNEL);
 881         err = -ENOMEM;
 882         if (!port) {
 883                 printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
 884                 goto err_out_release_mdesc;
 885         }
 886
 887         if (vdev->dev_no >= 26)
 888                 snprintf(port->disk_name, sizeof(port->disk_name),
 889                          VDCBLK_NAME "%c%c",
 890                          'a' + ((int)vdev->dev_no / 26) - 1,
 891                          'a' + ((int)vdev->dev_no % 26));
 892         else
 893                 snprintf(port->disk_name, sizeof(port->disk_name),
 894                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
 895         port->vdisk_size = -1;
 896
 897         /* Actual wall time may be double due to do_generic_file_read() doing
 898          * a readahead I/O first, and once that fails it will try to read a
 899          * single page.
 900          */
 901         ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
 902         port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
 903         setup_timer(&port->ldc_reset_timer, vdc_ldc_reset_timer,
 904                     (unsigned long)port);
 905         INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
 906
 907         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
 908                               vdc_versions, ARRAY_SIZE(vdc_versions),
 909                               &vdc_vio_ops, port->disk_name);
 910         if (err)
 911                 goto err_out_free_port;
 912
 913         port->vdisk_block_size = 512;
 914         port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size);
 915         port->ring_cookies = ((port->max_xfer_size *
 916                                port->vdisk_block_size) / PAGE_SIZE) + 2;
 917
 918         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
 919         if (err)
 920                 goto err_out_free_port;
 921
 922         err = vdc_alloc_tx_ring(port);
 923         if (err)
 924                 goto err_out_free_ldc;
 925
 926         err = probe_disk(port);
 927         if (err)
 928                 goto err_out_free_tx_ring;
 929
 930         dev_set_drvdata(&vdev->dev, port);
 931
 932         mdesc_release(hp);
 933
 934         return 0;
 935
 936 err_out_free_tx_ring:
 937         vdc_free_tx_ring(port);
 938
 939 err_out_free_ldc:
 940         vio_ldc_free(&port->vio);
 941
 942 err_out_free_port:
 943         kfree(port);
 944
 945 err_out_release_mdesc:
 946         mdesc_release(hp);
 947         return err;
 948 }
 949
 950 static int vdc_port_remove(struct vio_dev *vdev)
 951 {
 952         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
 953
 954         if (port) {
 955                 unsigned long flags;
 956
 957                 spin_lock_irqsave(&port->vio.lock, flags);
 958                 blk_stop_queue(port->disk->queue);
 959                 spin_unlock_irqrestore(&port->vio.lock, flags);
 960
 961                 flush_work(&port->ldc_reset_work);
 962                 del_timer_sync(&port->ldc_reset_timer);
 963                 del_timer_sync(&port->vio.timer);
 964
 965                 del_gendisk(port->disk);
 966                 blk_cleanup_queue(port->disk->queue);
 967                 put_disk(port->disk);
 968                 port->disk = NULL;
 969
 970                 vdc_free_tx_ring(port);
 971                 vio_ldc_free(&port->vio);
 972
 973                 dev_set_drvdata(&vdev->dev, NULL);
 974
 975                 kfree(port);
 976         }
 977         return 0;
 978 }
 979
 980 static void vdc_requeue_inflight(struct vdc_port *port)
 981 {
 982         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 983         u32 idx;
 984
 985         for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
 986                 struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
 987                 struct vdc_req_entry *rqe = &port->rq_arr[idx];
 988                 struct request *req;
 989
 990                 ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
 991                 desc->hdr.state = VIO_DESC_FREE;
 992                 dr->cons = vio_dring_next(dr, idx);
 993
 994                 req = rqe->req;
 995                 if (req == NULL) {
 996                         vdc_end_special(port, desc);
 997                         continue;
 998                 }
 999
1000                 rqe->req = NULL;
1001                 blk_requeue_request(port->disk->queue, req);
1002         }
1003 }
1004
1005 static void vdc_queue_drain(struct vdc_port *port)
1006 {
1007         struct request *req;
1008
1009         while ((req = blk_fetch_request(port->disk->queue)) != NULL)
1010                 __blk_end_request_all(req, -EIO);
1011 }
1012
1013 static void vdc_ldc_reset_timer(unsigned long _arg)
1014 {
1015         struct vdc_port *port = (struct vdc_port *) _arg;
1016         struct vio_driver_state *vio = &port->vio;
1017         unsigned long flags;
1018
1019         spin_lock_irqsave(&vio->lock, flags);
1020         if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
1021                 pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
1022                         port->disk_name, port->ldc_timeout);
1023                 vdc_queue_drain(port);
1024                 vdc_blk_queue_start(port);
1025         }
1026         spin_unlock_irqrestore(&vio->lock, flags);
1027 }
1028
1029 static void vdc_ldc_reset_work(struct work_struct *work)
1030 {
1031         struct vdc_port *port;
1032         struct vio_driver_state *vio;
1033         unsigned long flags;
1034
1035         port = container_of(work, struct vdc_port, ldc_reset_work);
1036         vio = &port->vio;
1037
1038         spin_lock_irqsave(&vio->lock, flags);
1039         vdc_ldc_reset(port);
1040         spin_unlock_irqrestore(&vio->lock, flags);
1041 }
1042
1043 static void vdc_ldc_reset(struct vdc_port *port)
1044 {
1045         int err;
1046
1047         assert_spin_locked(&port->vio.lock);
1048
1049         pr_warn(PFX "%s ldc link reset\n", port->disk_name);
1050         blk_stop_queue(port->disk->queue);
1051         vdc_requeue_inflight(port);
1052         vdc_port_down(port);
1053
1054         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1055         if (err) {
1056                 pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
1057                 return;
1058         }
1059
1060         err = vdc_alloc_tx_ring(port);
1061         if (err) {
1062                 pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
1063                 goto err_free_ldc;
1064         }
1065
1066         if (port->ldc_timeout)
1067                 mod_timer(&port->ldc_reset_timer,
1068                           round_jiffies(jiffies + HZ * port->ldc_timeout));
1069         mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
1070         return;
1071
1072 err_free_ldc:
1073         vio_ldc_free(&port->vio);
1074 }
1075
1076 static const struct vio_device_id vdc_port_match[] = {
1077         {
1078                 .type = "vdc-port",
1079         },
1080         {},
1081 };
1082 MODULE_DEVICE_TABLE(vio, vdc_port_match);
1083
1084 static struct vio_driver vdc_port_driver = {
1085         .id_table       = vdc_port_match,
1086         .probe          = vdc_port_probe,
1087         .remove         = vdc_port_remove,
1088         .name           = "vdc_port",
1089 };
1090
1091 static int __init vdc_init(void)
1092 {
1093         int err;
1094
1095         sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
1096         if (!sunvdc_wq)
1097                 return -ENOMEM;
1098
1099         err = register_blkdev(0, VDCBLK_NAME);
1100         if (err < 0)
1101                 goto out_free_wq;
1102
1103         vdc_major = err;
1104
1105         err = vio_register_driver(&vdc_port_driver);
1106         if (err)
1107                 goto out_unregister_blkdev;
1108
1109         return 0;
1110
1111 out_unregister_blkdev:
1112         unregister_blkdev(vdc_major, VDCBLK_NAME);
1113         vdc_major = 0;
1114
1115 out_free_wq:
1116         destroy_workqueue(sunvdc_wq);
1117         return err;
1118 }
1119
1120 static void __exit vdc_exit(void)
1121 {
1122         vio_unregister_driver(&vdc_port_driver);
1123         unregister_blkdev(vdc_major, VDCBLK_NAME);
1124         destroy_workqueue(sunvdc_wq);
1125 }
1126
1127 module_init(vdc_init);
1128 module_exit(vdc_exit);