drivers/block/sunvdc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* sunvdc.c: Sun LDOM Virtual Disk Client.
   3  *
   4  * Copyright (C) 2007, 2008 David S. Miller <davem@davemloft.net>
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/kernel.h>
   9 #include <linux/types.h>
  10 #include <linux/blk-mq.h>
  11 #include <linux/hdreg.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 #define VDC_DEFAULT_BLK_SIZE    512
  38
  39 #define MAX_XFER_BLKS           (128 * 1024)
  40 #define MAX_XFER_SIZE           (MAX_XFER_BLKS / VDC_DEFAULT_BLK_SIZE)
  41 #define MAX_RING_COOKIES        ((MAX_XFER_BLKS / PAGE_SIZE) + 2)
  42
  43 #define WAITING_FOR_LINK_UP     0x01
  44 #define WAITING_FOR_TX_SPACE    0x02
  45 #define WAITING_FOR_GEN_CMD     0x04
  46 #define WAITING_FOR_ANY         -1
  47
  48 #define VDC_MAX_RETRIES 10
  49
  50 static struct workqueue_struct *sunvdc_wq;
  51
  52 struct vdc_req_entry {
  53         struct request          *req;
  54 };
  55
  56 struct vdc_port {
  57         struct vio_driver_state vio;
  58
  59         struct gendisk          *disk;
  60
  61         struct vdc_completion   *cmp;
  62
  63         u64                     req_id;
  64         u64                     seq;
  65         struct vdc_req_entry    rq_arr[VDC_TX_RING_SIZE];
  66
  67         unsigned long           ring_cookies;
  68
  69         u64                     max_xfer_size;
  70         u32                     vdisk_block_size;
  71         u32                     drain;
  72
  73         u64                     ldc_timeout;
  74         struct delayed_work     ldc_reset_timer_work;
  75         struct work_struct      ldc_reset_work;
  76
  77         /* The server fills these in for us in the disk attribute
  78          * ACK packet.
  79          */
  80         u64                     operations;
  81         u32                     vdisk_size;
  82         u8                      vdisk_type;
  83         u8                      vdisk_mtype;
  84         u32                     vdisk_phys_blksz;
  85
  86         struct blk_mq_tag_set   tag_set;
  87
  88         char                    disk_name[32];
  89 };
  90
  91 static void vdc_ldc_reset(struct vdc_port *port);
  92 static void vdc_ldc_reset_work(struct work_struct *work);
  93 static void vdc_ldc_reset_timer_work(struct work_struct *work);
  94
  95 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
  96 {
  97         return container_of(vio, struct vdc_port, vio);
  98 }
  99
 100 /* Ordered from largest major to lowest */
 101 static struct vio_version vdc_versions[] = {
 102         { .major = 1, .minor = 2 },
 103         { .major = 1, .minor = 1 },
 104         { .major = 1, .minor = 0 },
 105 };
 106
 107 static inline int vdc_version_supported(struct vdc_port *port,
 108                                         u16 major, u16 minor)
 109 {
 110         return port->vio.ver.major == major && port->vio.ver.minor >= minor;
 111 }
 112
 113 #define VDCBLK_NAME     "vdisk"
 114 static int vdc_major;
 115 #define PARTITION_SHIFT 3
 116
 117 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
 118 {
 119         return vio_dring_avail(dr, VDC_TX_RING_SIZE);
 120 }
 121
 122 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 123 {
 124         struct gendisk *disk = bdev->bd_disk;
 125         sector_t nsect = get_capacity(disk);
 126         sector_t cylinders = nsect;
 127
 128         geo->heads = 0xff;
 129         geo->sectors = 0x3f;
 130         sector_div(cylinders, geo->heads * geo->sectors);
 131         geo->cylinders = cylinders;
 132         if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
 133                 geo->cylinders = 0xffff;
 134
 135         return 0;
 136 }
 137
 138 /* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
 139  * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
 140  * Needed to be able to install inside an ldom from an iso image.
 141  */
 142 static int vdc_ioctl(struct block_device *bdev, blk_mode_t mode,
 143                      unsigned command, unsigned long argument)
 144 {
 145         struct vdc_port *port = bdev->bd_disk->private_data;
 146         int i;
 147
 148         switch (command) {
 149         case CDROMMULTISESSION:
 150                 pr_debug(PFX "Multisession CDs not supported\n");
 151                 for (i = 0; i < sizeof(struct cdrom_multisession); i++)
 152                         if (put_user(0, (char __user *)(argument + i)))
 153                                 return -EFAULT;
 154                 return 0;
 155
 156         case CDROM_GET_CAPABILITY:
 157                 if (!vdc_version_supported(port, 1, 1))
 158                         return -EINVAL;
 159                 switch (port->vdisk_mtype) {
 160                 case VD_MEDIA_TYPE_CD:
 161                 case VD_MEDIA_TYPE_DVD:
 162                         return 0;
 163                 default:
 164                         return -EINVAL;
 165                 }
 166         default:
 167                 pr_debug(PFX "ioctl %08x not supported\n", command);
 168                 return -EINVAL;
 169         }
 170 }
 171
 172 static const struct block_device_operations vdc_fops = {
 173         .owner          = THIS_MODULE,
 174         .getgeo         = vdc_getgeo,
 175         .ioctl          = vdc_ioctl,
 176         .compat_ioctl   = blkdev_compat_ptr_ioctl,
 177 };
 178
 179 static void vdc_blk_queue_start(struct vdc_port *port)
 180 {
 181         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 182
 183         /* restart blk queue when ring is half emptied. also called after
 184          * handshake completes, so check for initial handshake before we've
 185          * allocated a disk.
 186          */
 187         if (port->disk && vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50)
 188                 blk_mq_start_stopped_hw_queues(port->disk->queue, true);
 189 }
 190
 191 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
 192 {
 193         if (vio->cmp &&
 194             (waiting_for == -1 ||
 195              vio->cmp->waiting_for == waiting_for)) {
 196                 vio->cmp->err = err;
 197                 complete(&vio->cmp->com);
 198                 vio->cmp = NULL;
 199         }
 200 }
 201
 202 static void vdc_handshake_complete(struct vio_driver_state *vio)
 203 {
 204         struct vdc_port *port = to_vdc_port(vio);
 205
 206         cancel_delayed_work(&port->ldc_reset_timer_work);
 207         vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
 208         vdc_blk_queue_start(port);
 209 }
 210
 211 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
 212 {
 213         struct vio_msg_tag *pkt = arg;
 214
 215         printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
 216                pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
 217         printk(KERN_ERR PFX "Resetting connection.\n");
 218
 219         ldc_disconnect(port->vio.lp);
 220
 221         return -ECONNRESET;
 222 }
 223
 224 static int vdc_send_attr(struct vio_driver_state *vio)
 225 {
 226         struct vdc_port *port = to_vdc_port(vio);
 227         struct vio_disk_attr_info pkt;
 228
 229         memset(&pkt, 0, sizeof(pkt));
 230
 231         pkt.tag.type = VIO_TYPE_CTRL;
 232         pkt.tag.stype = VIO_SUBTYPE_INFO;
 233         pkt.tag.stype_env = VIO_ATTR_INFO;
 234         pkt.tag.sid = vio_send_sid(vio);
 235
 236         pkt.xfer_mode = VIO_DRING_MODE;
 237         pkt.vdisk_block_size = port->vdisk_block_size;
 238         pkt.max_xfer_size = port->max_xfer_size;
 239
 240         viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 241                pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
 242
 243         return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
 244 }
 245
 246 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
 247 {
 248         struct vdc_port *port = to_vdc_port(vio);
 249         struct vio_disk_attr_info *pkt = arg;
 250
 251         viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
 252                "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 253                pkt->tag.stype, pkt->operations,
 254                pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
 255                pkt->xfer_mode, pkt->vdisk_block_size,
 256                pkt->max_xfer_size);
 257
 258         if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
 259                 switch (pkt->vdisk_type) {
 260                 case VD_DISK_TYPE_DISK:
 261                 case VD_DISK_TYPE_SLICE:
 262                         break;
 263
 264                 default:
 265                         printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
 266                                vio->name, pkt->vdisk_type);
 267                         return -ECONNRESET;
 268                 }
 269
 270                 if (pkt->vdisk_block_size > port->vdisk_block_size) {
 271                         printk(KERN_ERR PFX "%s: BLOCK size increased "
 272                                "%u --> %u\n",
 273                                vio->name,
 274                                port->vdisk_block_size, pkt->vdisk_block_size);
 275                         return -ECONNRESET;
 276                 }
 277
 278                 port->operations = pkt->operations;
 279                 port->vdisk_type = pkt->vdisk_type;
 280                 if (vdc_version_supported(port, 1, 1)) {
 281                         port->vdisk_size = pkt->vdisk_size;
 282                         port->vdisk_mtype = pkt->vdisk_mtype;
 283                 }
 284                 if (pkt->max_xfer_size < port->max_xfer_size)
 285                         port->max_xfer_size = pkt->max_xfer_size;
 286                 port->vdisk_block_size = pkt->vdisk_block_size;
 287
 288                 port->vdisk_phys_blksz = VDC_DEFAULT_BLK_SIZE;
 289                 if (vdc_version_supported(port, 1, 2))
 290                         port->vdisk_phys_blksz = pkt->phys_block_size;
 291
 292                 return 0;
 293         } else {
 294                 printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
 295
 296                 return -ECONNRESET;
 297         }
 298 }
 299
 300 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
 301 {
 302         int err = desc->status;
 303
 304         vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
 305 }
 306
 307 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
 308                         unsigned int index)
 309 {
 310         struct vio_disk_desc *desc = vio_dring_entry(dr, index);
 311         struct vdc_req_entry *rqe = &port->rq_arr[index];
 312         struct request *req;
 313
 314         if (unlikely(desc->hdr.state != VIO_DESC_DONE))
 315                 return;
 316
 317         ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
 318         desc->hdr.state = VIO_DESC_FREE;
 319         dr->cons = vio_dring_next(dr, index);
 320
 321         req = rqe->req;
 322         if (req == NULL) {
 323                 vdc_end_special(port, desc);
 324                 return;
 325         }
 326
 327         rqe->req = NULL;
 328
 329         blk_mq_end_request(req, desc->status ? BLK_STS_IOERR : 0);
 330
 331         vdc_blk_queue_start(port);
 332 }
 333
 334 static int vdc_ack(struct vdc_port *port, void *msgbuf)
 335 {
 336         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 337         struct vio_dring_data *pkt = msgbuf;
 338
 339         if (unlikely(pkt->dring_ident != dr->ident ||
 340                      pkt->start_idx != pkt->end_idx ||
 341                      pkt->start_idx >= VDC_TX_RING_SIZE))
 342                 return 0;
 343
 344         vdc_end_one(port, dr, pkt->start_idx);
 345
 346         return 0;
 347 }
 348
 349 static int vdc_nack(struct vdc_port *port, void *msgbuf)
 350 {
 351         /* XXX Implement me XXX */
 352         return 0;
 353 }
 354
 355 static void vdc_event(void *arg, int event)
 356 {
 357         struct vdc_port *port = arg;
 358         struct vio_driver_state *vio = &port->vio;
 359         unsigned long flags;
 360         int err;
 361
 362         spin_lock_irqsave(&vio->lock, flags);
 363
 364         if (unlikely(event == LDC_EVENT_RESET)) {
 365                 vio_link_state_change(vio, event);
 366                 queue_work(sunvdc_wq, &port->ldc_reset_work);
 367                 goto out;
 368         }
 369
 370         if (unlikely(event == LDC_EVENT_UP)) {
 371                 vio_link_state_change(vio, event);
 372                 goto out;
 373         }
 374
 375         if (unlikely(event != LDC_EVENT_DATA_READY)) {
 376                 pr_warn(PFX "Unexpected LDC event %d\n", event);
 377                 goto out;
 378         }
 379
 380         err = 0;
 381         while (1) {
 382                 union {
 383                         struct vio_msg_tag tag;
 384                         u64 raw[8];
 385                 } msgbuf;
 386
 387                 err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
 388                 if (unlikely(err < 0)) {
 389                         if (err == -ECONNRESET)
 390                                 vio_conn_reset(vio);
 391                         break;
 392                 }
 393                 if (err == 0)
 394                         break;
 395                 viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
 396                        msgbuf.tag.type,
 397                        msgbuf.tag.stype,
 398                        msgbuf.tag.stype_env,
 399                        msgbuf.tag.sid);
 400                 err = vio_validate_sid(vio, &msgbuf.tag);
 401                 if (err < 0)
 402                         break;
 403
 404                 if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
 405                         if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
 406                                 err = vdc_ack(port, &msgbuf);
 407                         else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
 408                                 err = vdc_nack(port, &msgbuf);
 409                         else
 410                                 err = vdc_handle_unknown(port, &msgbuf);
 411                 } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
 412                         err = vio_control_pkt_engine(vio, &msgbuf);
 413                 } else {
 414                         err = vdc_handle_unknown(port, &msgbuf);
 415                 }
 416                 if (err < 0)
 417                         break;
 418         }
 419         if (err < 0)
 420                 vdc_finish(&port->vio, err, WAITING_FOR_ANY);
 421 out:
 422         spin_unlock_irqrestore(&vio->lock, flags);
 423 }
 424
 425 static int __vdc_tx_trigger(struct vdc_port *port)
 426 {
 427         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 428         struct vio_dring_data hdr = {
 429                 .tag = {
 430                         .type           = VIO_TYPE_DATA,
 431                         .stype          = VIO_SUBTYPE_INFO,
 432                         .stype_env      = VIO_DRING_DATA,
 433                         .sid            = vio_send_sid(&port->vio),
 434                 },
 435                 .dring_ident            = dr->ident,
 436                 .start_idx              = dr->prod,
 437                 .end_idx                = dr->prod,
 438         };
 439         int err, delay;
 440         int retries = 0;
 441
 442         hdr.seq = dr->snd_nxt;
 443         delay = 1;
 444         do {
 445                 err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
 446                 if (err > 0) {
 447                         dr->snd_nxt++;
 448                         break;
 449                 }
 450                 udelay(delay);
 451                 if ((delay <<= 1) > 128)
 452                         delay = 128;
 453                 if (retries++ > VDC_MAX_RETRIES)
 454                         break;
 455         } while (err == -EAGAIN);
 456
 457         if (err == -ENOTCONN)
 458                 vdc_ldc_reset(port);
 459         return err;
 460 }
 461
 462 static int __send_request(struct request *req)
 463 {
 464         struct vdc_port *port = req->q->disk->private_data;
 465         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 466         struct scatterlist sg[MAX_RING_COOKIES];
 467         struct vdc_req_entry *rqe;
 468         struct vio_disk_desc *desc;
 469         unsigned int map_perm;
 470         int nsg, err, i;
 471         u64 len;
 472         u8 op;
 473
 474         if (WARN_ON(port->ring_cookies > MAX_RING_COOKIES))
 475                 return -EINVAL;
 476
 477         map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 478
 479         if (rq_data_dir(req) == READ) {
 480                 map_perm |= LDC_MAP_W;
 481                 op = VD_OP_BREAD;
 482         } else {
 483                 map_perm |= LDC_MAP_R;
 484                 op = VD_OP_BWRITE;
 485         }
 486
 487         sg_init_table(sg, port->ring_cookies);
 488         nsg = blk_rq_map_sg(req->q, req, sg);
 489
 490         len = 0;
 491         for (i = 0; i < nsg; i++)
 492                 len += sg[i].length;
 493
 494         desc = vio_dring_cur(dr);
 495
 496         err = ldc_map_sg(port->vio.lp, sg, nsg,
 497                          desc->cookies, port->ring_cookies,
 498                          map_perm);
 499         if (err < 0) {
 500                 printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
 501                 return err;
 502         }
 503
 504         rqe = &port->rq_arr[dr->prod];
 505         rqe->req = req;
 506
 507         desc->hdr.ack = VIO_ACK_ENABLE;
 508         desc->req_id = port->req_id;
 509         desc->operation = op;
 510         if (port->vdisk_type == VD_DISK_TYPE_DISK) {
 511                 desc->slice = 0xff;
 512         } else {
 513                 desc->slice = 0;
 514         }
 515         desc->status = ~0;
 516         desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
 517         desc->size = len;
 518         desc->ncookies = err;
 519
 520         /* This has to be a non-SMP write barrier because we are writing
 521          * to memory which is shared with the peer LDOM.
 522          */
 523         wmb();
 524         desc->hdr.state = VIO_DESC_READY;
 525
 526         err = __vdc_tx_trigger(port);
 527         if (err < 0) {
 528                 printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
 529         } else {
 530                 port->req_id++;
 531                 dr->prod = vio_dring_next(dr, dr->prod);
 532         }
 533
 534         return err;
 535 }
 536
 537 static blk_status_t vdc_queue_rq(struct blk_mq_hw_ctx *hctx,
 538                                  const struct blk_mq_queue_data *bd)
 539 {
 540         struct vdc_port *port = hctx->queue->queuedata;
 541         struct vio_dring_state *dr;
 542         unsigned long flags;
 543
 544         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 545
 546         blk_mq_start_request(bd->rq);
 547
 548         spin_lock_irqsave(&port->vio.lock, flags);
 549
 550         /*
 551          * Doing drain, just end the request in error
 552          */
 553         if (unlikely(port->drain)) {
 554                 spin_unlock_irqrestore(&port->vio.lock, flags);
 555                 return BLK_STS_IOERR;
 556         }
 557
 558         if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
 559                 spin_unlock_irqrestore(&port->vio.lock, flags);
 560                 blk_mq_stop_hw_queue(hctx);
 561                 return BLK_STS_DEV_RESOURCE;
 562         }
 563
 564         if (__send_request(bd->rq) < 0) {
 565                 spin_unlock_irqrestore(&port->vio.lock, flags);
 566                 return BLK_STS_IOERR;
 567         }
 568
 569         spin_unlock_irqrestore(&port->vio.lock, flags);
 570         return BLK_STS_OK;
 571 }
 572
 573 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
 574 {
 575         struct vio_dring_state *dr;
 576         struct vio_completion comp;
 577         struct vio_disk_desc *desc;
 578         unsigned int map_perm;
 579         unsigned long flags;
 580         int op_len, err;
 581         void *req_buf;
 582
 583         if (!(((u64)1 << (u64)op) & port->operations))
 584                 return -EOPNOTSUPP;
 585
 586         switch (op) {
 587         case VD_OP_BREAD:
 588         case VD_OP_BWRITE:
 589         default:
 590                 return -EINVAL;
 591
 592         case VD_OP_FLUSH:
 593                 op_len = 0;
 594                 map_perm = 0;
 595                 break;
 596
 597         case VD_OP_GET_WCE:
 598                 op_len = sizeof(u32);
 599                 map_perm = LDC_MAP_W;
 600                 break;
 601
 602         case VD_OP_SET_WCE:
 603                 op_len = sizeof(u32);
 604                 map_perm = LDC_MAP_R;
 605                 break;
 606
 607         case VD_OP_GET_VTOC:
 608                 op_len = sizeof(struct vio_disk_vtoc);
 609                 map_perm = LDC_MAP_W;
 610                 break;
 611
 612         case VD_OP_SET_VTOC:
 613                 op_len = sizeof(struct vio_disk_vtoc);
 614                 map_perm = LDC_MAP_R;
 615                 break;
 616
 617         case VD_OP_GET_DISKGEOM:
 618                 op_len = sizeof(struct vio_disk_geom);
 619                 map_perm = LDC_MAP_W;
 620                 break;
 621
 622         case VD_OP_SET_DISKGEOM:
 623                 op_len = sizeof(struct vio_disk_geom);
 624                 map_perm = LDC_MAP_R;
 625                 break;
 626
 627         case VD_OP_SCSICMD:
 628                 op_len = 16;
 629                 map_perm = LDC_MAP_RW;
 630                 break;
 631
 632         case VD_OP_GET_DEVID:
 633                 op_len = sizeof(struct vio_disk_devid);
 634                 map_perm = LDC_MAP_W;
 635                 break;
 636
 637         case VD_OP_GET_EFI:
 638         case VD_OP_SET_EFI:
 639                 return -EOPNOTSUPP;
 640         }
 641
 642         map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 643
 644         op_len = (op_len + 7) & ~7;
 645         req_buf = kzalloc(op_len, GFP_KERNEL);
 646         if (!req_buf)
 647                 return -ENOMEM;
 648
 649         if (len > op_len)
 650                 len = op_len;
 651
 652         if (map_perm & LDC_MAP_R)
 653                 memcpy(req_buf, buf, len);
 654
 655         spin_lock_irqsave(&port->vio.lock, flags);
 656
 657         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 658
 659         /* XXX If we want to use this code generically we have to
 660          * XXX handle TX ring exhaustion etc.
 661          */
 662         desc = vio_dring_cur(dr);
 663
 664         err = ldc_map_single(port->vio.lp, req_buf, op_len,
 665                              desc->cookies, port->ring_cookies,
 666                              map_perm);
 667         if (err < 0) {
 668                 spin_unlock_irqrestore(&port->vio.lock, flags);
 669                 kfree(req_buf);
 670                 return err;
 671         }
 672
 673         init_completion(&comp.com);
 674         comp.waiting_for = WAITING_FOR_GEN_CMD;
 675         port->vio.cmp = &comp;
 676
 677         desc->hdr.ack = VIO_ACK_ENABLE;
 678         desc->req_id = port->req_id;
 679         desc->operation = op;
 680         desc->slice = 0;
 681         desc->status = ~0;
 682         desc->offset = 0;
 683         desc->size = op_len;
 684         desc->ncookies = err;
 685
 686         /* This has to be a non-SMP write barrier because we are writing
 687          * to memory which is shared with the peer LDOM.
 688          */
 689         wmb();
 690         desc->hdr.state = VIO_DESC_READY;
 691
 692         err = __vdc_tx_trigger(port);
 693         if (err >= 0) {
 694                 port->req_id++;
 695                 dr->prod = vio_dring_next(dr, dr->prod);
 696                 spin_unlock_irqrestore(&port->vio.lock, flags);
 697
 698                 wait_for_completion(&comp.com);
 699                 err = comp.err;
 700         } else {
 701                 port->vio.cmp = NULL;
 702                 spin_unlock_irqrestore(&port->vio.lock, flags);
 703         }
 704
 705         if (map_perm & LDC_MAP_W)
 706                 memcpy(buf, req_buf, len);
 707
 708         kfree(req_buf);
 709
 710         return err;
 711 }
 712
 713 static int vdc_alloc_tx_ring(struct vdc_port *port)
 714 {
 715         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 716         unsigned long len, entry_size;
 717         int ncookies;
 718         void *dring;
 719
 720         entry_size = sizeof(struct vio_disk_desc) +
 721                 (sizeof(struct ldc_trans_cookie) * port->ring_cookies);
 722         len = (VDC_TX_RING_SIZE * entry_size);
 723
 724         ncookies = VIO_MAX_RING_COOKIES;
 725         dring = ldc_alloc_exp_dring(port->vio.lp, len,
 726                                     dr->cookies, &ncookies,
 727                                     (LDC_MAP_SHADOW |
 728                                      LDC_MAP_DIRECT |
 729                                      LDC_MAP_RW));
 730         if (IS_ERR(dring))
 731                 return PTR_ERR(dring);
 732
 733         dr->base = dring;
 734         dr->entry_size = entry_size;
 735         dr->num_entries = VDC_TX_RING_SIZE;
 736         dr->prod = dr->cons = 0;
 737         dr->pending = VDC_TX_RING_SIZE;
 738         dr->ncookies = ncookies;
 739
 740         return 0;
 741 }
 742
 743 static void vdc_free_tx_ring(struct vdc_port *port)
 744 {
 745         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 746
 747         if (dr->base) {
 748                 ldc_free_exp_dring(port->vio.lp, dr->base,
 749                                    (dr->entry_size * dr->num_entries),
 750                                    dr->cookies, dr->ncookies);
 751                 dr->base = NULL;
 752                 dr->entry_size = 0;
 753                 dr->num_entries = 0;
 754                 dr->pending = 0;
 755                 dr->ncookies = 0;
 756         }
 757 }
 758
 759 static int vdc_port_up(struct vdc_port *port)
 760 {
 761         struct vio_completion comp;
 762
 763         init_completion(&comp.com);
 764         comp.err = 0;
 765         comp.waiting_for = WAITING_FOR_LINK_UP;
 766         port->vio.cmp = &comp;
 767
 768         vio_port_up(&port->vio);
 769         wait_for_completion(&comp.com);
 770         return comp.err;
 771 }
 772
 773 static void vdc_port_down(struct vdc_port *port)
 774 {
 775         ldc_disconnect(port->vio.lp);
 776         ldc_unbind(port->vio.lp);
 777         vdc_free_tx_ring(port);
 778         vio_ldc_free(&port->vio);
 779 }
 780
 781 static const struct blk_mq_ops vdc_mq_ops = {
 782         .queue_rq       = vdc_queue_rq,
 783 };
 784
 785 static int probe_disk(struct vdc_port *port)
 786 {
 787         struct queue_limits lim = {
 788                 .physical_block_size            = port->vdisk_phys_blksz,
 789                 .max_hw_sectors                 = port->max_xfer_size,
 790                 /* Each segment in a request is up to an aligned page in size. */
 791                 .seg_boundary_mask              = PAGE_SIZE - 1,
 792                 .max_segment_size               = PAGE_SIZE,
 793                 .max_segments                   = port->ring_cookies,
 794         };
 795         struct request_queue *q;
 796         struct gendisk *g;
 797         int err;
 798
 799         err = vdc_port_up(port);
 800         if (err)
 801                 return err;
 802
 803         /* Using version 1.2 means vdisk_phys_blksz should be set unless the
 804          * disk is reserved by another system.
 805          */
 806         if (vdc_version_supported(port, 1, 2) && !port->vdisk_phys_blksz)
 807                 return -ENODEV;
 808
 809         if (vdc_version_supported(port, 1, 1)) {
 810                 /* vdisk_size should be set during the handshake, if it wasn't
 811                  * then the underlying disk is reserved by another system
 812                  */
 813                 if (port->vdisk_size == -1)
 814                         return -ENODEV;
 815         } else {
 816                 struct vio_disk_geom geom;
 817
 818                 err = generic_request(port, VD_OP_GET_DISKGEOM,
 819                                       &geom, sizeof(geom));
 820                 if (err < 0) {
 821                         printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
 822                                "error %d\n", err);
 823                         return err;
 824                 }
 825                 port->vdisk_size = ((u64)geom.num_cyl *
 826                                     (u64)geom.num_hd *
 827                                     (u64)geom.num_sec);
 828         }
 829
 830         err = blk_mq_alloc_sq_tag_set(&port->tag_set, &vdc_mq_ops,
 831                         VDC_TX_RING_SIZE, BLK_MQ_F_SHOULD_MERGE);
 832         if (err)
 833                 return err;
 834
 835         g = blk_mq_alloc_disk(&port->tag_set, &lim, port);
 836         if (IS_ERR(g)) {
 837                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
 838                        port->vio.name);
 839                 err = PTR_ERR(g);
 840                 goto out_free_tag;
 841         }
 842
 843         port->disk = g;
 844         q = g->queue;
 845
 846         g->major = vdc_major;
 847         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
 848         g->minors = 1 << PARTITION_SHIFT;
 849         strcpy(g->disk_name, port->disk_name);
 850
 851         g->fops = &vdc_fops;
 852         g->queue = q;
 853         g->private_data = port;
 854
 855         set_capacity(g, port->vdisk_size);
 856
 857         if (vdc_version_supported(port, 1, 1)) {
 858                 switch (port->vdisk_mtype) {
 859                 case VD_MEDIA_TYPE_CD:
 860                         pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
 861                         g->flags |= GENHD_FL_REMOVABLE;
 862                         set_disk_ro(g, 1);
 863                         break;
 864
 865                 case VD_MEDIA_TYPE_DVD:
 866                         pr_info(PFX "Virtual DVD %s\n", port->disk_name);
 867                         g->flags |= GENHD_FL_REMOVABLE;
 868                         set_disk_ro(g, 1);
 869                         break;
 870
 871                 case VD_MEDIA_TYPE_FIXED:
 872                         pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
 873                         break;
 874                 }
 875         }
 876
 877         pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
 878                g->disk_name,
 879                port->vdisk_size, (port->vdisk_size >> (20 - 9)),
 880                port->vio.ver.major, port->vio.ver.minor);
 881
 882         err = device_add_disk(&port->vio.vdev->dev, g, NULL);
 883         if (err)
 884                 goto out_cleanup_disk;
 885
 886         return 0;
 887
 888 out_cleanup_disk:
 889         put_disk(g);
 890 out_free_tag:
 891         blk_mq_free_tag_set(&port->tag_set);
 892         return err;
 893 }
 894
 895 static struct ldc_channel_config vdc_ldc_cfg = {
 896         .event          = vdc_event,
 897         .mtu            = 64,
 898         .mode           = LDC_MODE_UNRELIABLE,
 899 };
 900
 901 static struct vio_driver_ops vdc_vio_ops = {
 902         .send_attr              = vdc_send_attr,
 903         .handle_attr            = vdc_handle_attr,
 904         .handshake_complete     = vdc_handshake_complete,
 905 };
 906
 907 static void print_version(void)
 908 {
 909         static int version_printed;
 910
 911         if (version_printed++ == 0)
 912                 printk(KERN_INFO "%s", version);
 913 }
 914
 915 struct vdc_check_port_data {
 916         int     dev_no;
 917         char    *type;
 918 };
 919
 920 static int vdc_device_probed(struct device *dev, void *arg)
 921 {
 922         struct vio_dev *vdev = to_vio_dev(dev);
 923         struct vdc_check_port_data *port_data;
 924
 925         port_data = (struct vdc_check_port_data *)arg;
 926
 927         if ((vdev->dev_no == port_data->dev_no) &&
 928             (!(strcmp((char *)&vdev->type, port_data->type))) &&
 929                 dev_get_drvdata(dev)) {
 930                 /* This device has already been configured
 931                  * by vdc_port_probe()
 932                  */
 933                 return 1;
 934         } else {
 935                 return 0;
 936         }
 937 }
 938
 939 /* Determine whether the VIO device is part of an mpgroup
 940  * by locating all the virtual-device-port nodes associated
 941  * with the parent virtual-device node for the VIO device
 942  * and checking whether any of these nodes are vdc-ports
 943  * which have already been configured.
 944  *
 945  * Returns true if this device is part of an mpgroup and has
 946  * already been probed.
 947  */
 948 static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
 949 {
 950         struct vdc_check_port_data port_data;
 951         struct device *dev;
 952
 953         port_data.dev_no = vdev->dev_no;
 954         port_data.type = (char *)&vdev->type;
 955
 956         dev = device_find_child(vdev->dev.parent, &port_data,
 957                                 vdc_device_probed);
 958
 959         if (dev)
 960                 return true;
 961
 962         return false;
 963 }
 964
 965 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 966 {
 967         struct mdesc_handle *hp;
 968         struct vdc_port *port;
 969         int err;
 970         const u64 *ldc_timeout;
 971
 972         print_version();
 973
 974         hp = mdesc_grab();
 975         if (!hp)
 976                 return -ENODEV;
 977
 978         err = -ENODEV;
 979         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
 980                 printk(KERN_ERR PFX "Port id [%llu] too large.\n",
 981                        vdev->dev_no);
 982                 goto err_out_release_mdesc;
 983         }
 984
 985         /* Check if this device is part of an mpgroup */
 986         if (vdc_port_mpgroup_check(vdev)) {
 987                 printk(KERN_WARNING
 988                         "VIO: Ignoring extra vdisk port %s",
 989                         dev_name(&vdev->dev));
 990                 goto err_out_release_mdesc;
 991         }
 992
 993         port = kzalloc(sizeof(*port), GFP_KERNEL);
 994         if (!port) {
 995                 err = -ENOMEM;
 996                 goto err_out_release_mdesc;
 997         }
 998
 999         if (vdev->dev_no >= 26)
1000                 snprintf(port->disk_name, sizeof(port->disk_name),
1001                          VDCBLK_NAME "%c%c",
1002                          'a' + ((int)vdev->dev_no / 26) - 1,
1003                          'a' + ((int)vdev->dev_no % 26));
1004         else
1005                 snprintf(port->disk_name, sizeof(port->disk_name),
1006                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
1007         port->vdisk_size = -1;
1008
1009         /* Actual wall time may be double due to do_generic_file_read() doing
1010          * a readahead I/O first, and once that fails it will try to read a
1011          * single page.
1012          */
1013         ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
1014         port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
1015         INIT_DELAYED_WORK(&port->ldc_reset_timer_work, vdc_ldc_reset_timer_work);
1016         INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
1017
1018         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
1019                               vdc_versions, ARRAY_SIZE(vdc_versions),
1020                               &vdc_vio_ops, port->disk_name);
1021         if (err)
1022                 goto err_out_free_port;
1023
1024         port->vdisk_block_size = VDC_DEFAULT_BLK_SIZE;
1025         port->max_xfer_size = MAX_XFER_SIZE;
1026         port->ring_cookies = MAX_RING_COOKIES;
1027
1028         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1029         if (err)
1030                 goto err_out_free_port;
1031
1032         err = vdc_alloc_tx_ring(port);
1033         if (err)
1034                 goto err_out_free_ldc;
1035
1036         err = probe_disk(port);
1037         if (err)
1038                 goto err_out_free_tx_ring;
1039
1040         /* Note that the device driver_data is used to determine
1041          * whether the port has been probed.
1042          */
1043         dev_set_drvdata(&vdev->dev, port);
1044
1045         mdesc_release(hp);
1046
1047         return 0;
1048
1049 err_out_free_tx_ring:
1050         vdc_free_tx_ring(port);
1051
1052 err_out_free_ldc:
1053         vio_ldc_free(&port->vio);
1054
1055 err_out_free_port:
1056         kfree(port);
1057
1058 err_out_release_mdesc:
1059         mdesc_release(hp);
1060         return err;
1061 }
1062
1063 static void vdc_port_remove(struct vio_dev *vdev)
1064 {
1065         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
1066
1067         if (port) {
1068                 blk_mq_stop_hw_queues(port->disk->queue);
1069
1070                 flush_work(&port->ldc_reset_work);
1071                 cancel_delayed_work_sync(&port->ldc_reset_timer_work);
1072                 del_timer_sync(&port->vio.timer);
1073
1074                 del_gendisk(port->disk);
1075                 put_disk(port->disk);
1076                 blk_mq_free_tag_set(&port->tag_set);
1077
1078                 vdc_free_tx_ring(port);
1079                 vio_ldc_free(&port->vio);
1080
1081                 dev_set_drvdata(&vdev->dev, NULL);
1082
1083                 kfree(port);
1084         }
1085 }
1086
1087 static void vdc_requeue_inflight(struct vdc_port *port)
1088 {
1089         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1090         u32 idx;
1091
1092         for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
1093                 struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
1094                 struct vdc_req_entry *rqe = &port->rq_arr[idx];
1095                 struct request *req;
1096
1097                 ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
1098                 desc->hdr.state = VIO_DESC_FREE;
1099                 dr->cons = vio_dring_next(dr, idx);
1100
1101                 req = rqe->req;
1102                 if (req == NULL) {
1103                         vdc_end_special(port, desc);
1104                         continue;
1105                 }
1106
1107                 rqe->req = NULL;
1108                 blk_mq_requeue_request(req, false);
1109         }
1110 }
1111
1112 static void vdc_queue_drain(struct vdc_port *port)
1113 {
1114         struct request_queue *q = port->disk->queue;
1115
1116         /*
1117          * Mark the queue as draining, then freeze/quiesce to ensure
1118          * that all existing requests are seen in ->queue_rq() and killed
1119          */
1120         port->drain = 1;
1121         spin_unlock_irq(&port->vio.lock);
1122
1123         blk_mq_freeze_queue(q);
1124         blk_mq_quiesce_queue(q);
1125
1126         spin_lock_irq(&port->vio.lock);
1127         port->drain = 0;
1128         blk_mq_unquiesce_queue(q);
1129         blk_mq_unfreeze_queue(q);
1130 }
1131
1132 static void vdc_ldc_reset_timer_work(struct work_struct *work)
1133 {
1134         struct vdc_port *port;
1135         struct vio_driver_state *vio;
1136
1137         port = container_of(work, struct vdc_port, ldc_reset_timer_work.work);
1138         vio = &port->vio;
1139
1140         spin_lock_irq(&vio->lock);
1141         if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
1142                 pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
1143                         port->disk_name, port->ldc_timeout);
1144                 vdc_queue_drain(port);
1145                 vdc_blk_queue_start(port);
1146         }
1147         spin_unlock_irq(&vio->lock);
1148 }
1149
1150 static void vdc_ldc_reset_work(struct work_struct *work)
1151 {
1152         struct vdc_port *port;
1153         struct vio_driver_state *vio;
1154         unsigned long flags;
1155
1156         port = container_of(work, struct vdc_port, ldc_reset_work);
1157         vio = &port->vio;
1158
1159         spin_lock_irqsave(&vio->lock, flags);
1160         vdc_ldc_reset(port);
1161         spin_unlock_irqrestore(&vio->lock, flags);
1162 }
1163
1164 static void vdc_ldc_reset(struct vdc_port *port)
1165 {
1166         int err;
1167
1168         assert_spin_locked(&port->vio.lock);
1169
1170         pr_warn(PFX "%s ldc link reset\n", port->disk_name);
1171         blk_mq_stop_hw_queues(port->disk->queue);
1172         vdc_requeue_inflight(port);
1173         vdc_port_down(port);
1174
1175         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1176         if (err) {
1177                 pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
1178                 return;
1179         }
1180
1181         err = vdc_alloc_tx_ring(port);
1182         if (err) {
1183                 pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
1184                 goto err_free_ldc;
1185         }
1186
1187         if (port->ldc_timeout)
1188                 mod_delayed_work(system_wq, &port->ldc_reset_timer_work,
1189                           round_jiffies(jiffies + HZ * port->ldc_timeout));
1190         mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
1191         return;
1192
1193 err_free_ldc:
1194         vio_ldc_free(&port->vio);
1195 }
1196
1197 static const struct vio_device_id vdc_port_match[] = {
1198         {
1199                 .type = "vdc-port",
1200         },
1201         {},
1202 };
1203 MODULE_DEVICE_TABLE(vio, vdc_port_match);
1204
1205 static struct vio_driver vdc_port_driver = {
1206         .id_table       = vdc_port_match,
1207         .probe          = vdc_port_probe,
1208         .remove         = vdc_port_remove,
1209         .name           = "vdc_port",
1210 };
1211
1212 static int __init vdc_init(void)
1213 {
1214         int err;
1215
1216         sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
1217         if (!sunvdc_wq)
1218                 return -ENOMEM;
1219
1220         err = register_blkdev(0, VDCBLK_NAME);
1221         if (err < 0)
1222                 goto out_free_wq;
1223
1224         vdc_major = err;
1225
1226         err = vio_register_driver(&vdc_port_driver);
1227         if (err)
1228                 goto out_unregister_blkdev;
1229
1230         return 0;
1231
1232 out_unregister_blkdev:
1233         unregister_blkdev(vdc_major, VDCBLK_NAME);
1234         vdc_major = 0;
1235
1236 out_free_wq:
1237         destroy_workqueue(sunvdc_wq);
1238         return err;
1239 }
1240
1241 static void __exit vdc_exit(void)
1242 {
1243         vio_unregister_driver(&vdc_port_driver);
1244         unregister_blkdev(vdc_major, VDCBLK_NAME);
1245         destroy_workqueue(sunvdc_wq);
1246 }
1247
1248 module_init(vdc_init);
1249 module_exit(vdc_exit);