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/genhd.h>
  13 #include <linux/cdrom.h>
  14 #include <linux/slab.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/completion.h>
  17 #include <linux/delay.h>
  18 #include <linux/init.h>
  19 #include <linux/list.h>
  20 #include <linux/scatterlist.h>
  21
  22 #include <asm/vio.h>
  23 #include <asm/ldc.h>
  24
  25 #define DRV_MODULE_NAME         "sunvdc"
  26 #define PFX DRV_MODULE_NAME     ": "
  27 #define DRV_MODULE_VERSION      "1.2"
  28 #define DRV_MODULE_RELDATE      "November 24, 2014"
  29
  30 static char version[] =
  31         DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
  32 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
  33 MODULE_DESCRIPTION("Sun LDOM virtual disk client driver");
  34 MODULE_LICENSE("GPL");
  35 MODULE_VERSION(DRV_MODULE_VERSION);
  36
  37 #define VDC_TX_RING_SIZE        512
  38 #define VDC_DEFAULT_BLK_SIZE    512
  39
  40 #define MAX_XFER_BLKS           (128 * 1024)
  41 #define MAX_XFER_SIZE           (MAX_XFER_BLKS / VDC_DEFAULT_BLK_SIZE)
  42 #define MAX_RING_COOKIES        ((MAX_XFER_BLKS / PAGE_SIZE) + 2)
  43
  44 #define WAITING_FOR_LINK_UP     0x01
  45 #define WAITING_FOR_TX_SPACE    0x02
  46 #define WAITING_FOR_GEN_CMD     0x04
  47 #define WAITING_FOR_ANY         -1
  48
  49 #define VDC_MAX_RETRIES 10
  50
  51 static struct workqueue_struct *sunvdc_wq;
  52
  53 struct vdc_req_entry {
  54         struct request          *req;
  55 };
  56
  57 struct vdc_port {
  58         struct vio_driver_state vio;
  59
  60         struct gendisk          *disk;
  61
  62         struct vdc_completion   *cmp;
  63
  64         u64                     req_id;
  65         u64                     seq;
  66         struct vdc_req_entry    rq_arr[VDC_TX_RING_SIZE];
  67
  68         unsigned long           ring_cookies;
  69
  70         u64                     max_xfer_size;
  71         u32                     vdisk_block_size;
  72         u32                     drain;
  73
  74         u64                     ldc_timeout;
  75         struct delayed_work     ldc_reset_timer_work;
  76         struct work_struct      ldc_reset_work;
  77
  78         /* The server fills these in for us in the disk attribute
  79          * ACK packet.
  80          */
  81         u64                     operations;
  82         u32                     vdisk_size;
  83         u8                      vdisk_type;
  84         u8                      vdisk_mtype;
  85         u32                     vdisk_phys_blksz;
  86
  87         struct blk_mq_tag_set   tag_set;
  88
  89         char                    disk_name[32];
  90 };
  91
  92 static void vdc_ldc_reset(struct vdc_port *port);
  93 static void vdc_ldc_reset_work(struct work_struct *work);
  94 static void vdc_ldc_reset_timer_work(struct work_struct *work);
  95
  96 static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
  97 {
  98         return container_of(vio, struct vdc_port, vio);
  99 }
 100
 101 /* Ordered from largest major to lowest */
 102 static struct vio_version vdc_versions[] = {
 103         { .major = 1, .minor = 2 },
 104         { .major = 1, .minor = 1 },
 105         { .major = 1, .minor = 0 },
 106 };
 107
 108 static inline int vdc_version_supported(struct vdc_port *port,
 109                                         u16 major, u16 minor)
 110 {
 111         return port->vio.ver.major == major && port->vio.ver.minor >= minor;
 112 }
 113
 114 #define VDCBLK_NAME     "vdisk"
 115 static int vdc_major;
 116 #define PARTITION_SHIFT 3
 117
 118 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr)
 119 {
 120         return vio_dring_avail(dr, VDC_TX_RING_SIZE);
 121 }
 122
 123 static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 124 {
 125         struct gendisk *disk = bdev->bd_disk;
 126         sector_t nsect = get_capacity(disk);
 127         sector_t cylinders = nsect;
 128
 129         geo->heads = 0xff;
 130         geo->sectors = 0x3f;
 131         sector_div(cylinders, geo->heads * geo->sectors);
 132         geo->cylinders = cylinders;
 133         if ((sector_t)(geo->cylinders + 1) * geo->heads * geo->sectors < nsect)
 134                 geo->cylinders = 0xffff;
 135
 136         return 0;
 137 }
 138
 139 /* Add ioctl/CDROM_GET_CAPABILITY to support cdrom_id in udev
 140  * when vdisk_mtype is VD_MEDIA_TYPE_CD or VD_MEDIA_TYPE_DVD.
 141  * Needed to be able to install inside an ldom from an iso image.
 142  */
 143 static int vdc_ioctl(struct block_device *bdev, fmode_t mode,
 144                      unsigned command, unsigned long argument)
 145 {
 146         int i;
 147         struct gendisk *disk;
 148
 149         switch (command) {
 150         case CDROMMULTISESSION:
 151                 pr_debug(PFX "Multisession CDs not supported\n");
 152                 for (i = 0; i < sizeof(struct cdrom_multisession); i++)
 153                         if (put_user(0, (char __user *)(argument + i)))
 154                                 return -EFAULT;
 155                 return 0;
 156
 157         case CDROM_GET_CAPABILITY:
 158                 disk = bdev->bd_disk;
 159
 160                 if (bdev->bd_disk && (disk->flags & GENHD_FL_CD))
 161                         return 0;
 162                 return -EINVAL;
 163
 164         default:
 165                 pr_debug(PFX "ioctl %08x not supported\n", command);
 166                 return -EINVAL;
 167         }
 168 }
 169
 170 static const struct block_device_operations vdc_fops = {
 171         .owner          = THIS_MODULE,
 172         .getgeo         = vdc_getgeo,
 173         .ioctl          = vdc_ioctl,
 174         .compat_ioctl   = blkdev_compat_ptr_ioctl,
 175 };
 176
 177 static void vdc_blk_queue_start(struct vdc_port *port)
 178 {
 179         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 180
 181         /* restart blk queue when ring is half emptied. also called after
 182          * handshake completes, so check for initial handshake before we've
 183          * allocated a disk.
 184          */
 185         if (port->disk && vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50)
 186                 blk_mq_start_stopped_hw_queues(port->disk->queue, true);
 187 }
 188
 189 static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
 190 {
 191         if (vio->cmp &&
 192             (waiting_for == -1 ||
 193              vio->cmp->waiting_for == waiting_for)) {
 194                 vio->cmp->err = err;
 195                 complete(&vio->cmp->com);
 196                 vio->cmp = NULL;
 197         }
 198 }
 199
 200 static void vdc_handshake_complete(struct vio_driver_state *vio)
 201 {
 202         struct vdc_port *port = to_vdc_port(vio);
 203
 204         cancel_delayed_work(&port->ldc_reset_timer_work);
 205         vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
 206         vdc_blk_queue_start(port);
 207 }
 208
 209 static int vdc_handle_unknown(struct vdc_port *port, void *arg)
 210 {
 211         struct vio_msg_tag *pkt = arg;
 212
 213         printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n",
 214                pkt->type, pkt->stype, pkt->stype_env, pkt->sid);
 215         printk(KERN_ERR PFX "Resetting connection.\n");
 216
 217         ldc_disconnect(port->vio.lp);
 218
 219         return -ECONNRESET;
 220 }
 221
 222 static int vdc_send_attr(struct vio_driver_state *vio)
 223 {
 224         struct vdc_port *port = to_vdc_port(vio);
 225         struct vio_disk_attr_info pkt;
 226
 227         memset(&pkt, 0, sizeof(pkt));
 228
 229         pkt.tag.type = VIO_TYPE_CTRL;
 230         pkt.tag.stype = VIO_SUBTYPE_INFO;
 231         pkt.tag.stype_env = VIO_ATTR_INFO;
 232         pkt.tag.sid = vio_send_sid(vio);
 233
 234         pkt.xfer_mode = VIO_DRING_MODE;
 235         pkt.vdisk_block_size = port->vdisk_block_size;
 236         pkt.max_xfer_size = port->max_xfer_size;
 237
 238         viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 239                pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size);
 240
 241         return vio_ldc_send(&port->vio, &pkt, sizeof(pkt));
 242 }
 243
 244 static int vdc_handle_attr(struct vio_driver_state *vio, void *arg)
 245 {
 246         struct vdc_port *port = to_vdc_port(vio);
 247         struct vio_disk_attr_info *pkt = arg;
 248
 249         viodbg(HS, "GOT ATTR stype[0x%x] ops[%llx] disk_size[%llu] disk_type[%x] "
 250                "mtype[0x%x] xfer_mode[0x%x] blksz[%u] max_xfer[%llu]\n",
 251                pkt->tag.stype, pkt->operations,
 252                pkt->vdisk_size, pkt->vdisk_type, pkt->vdisk_mtype,
 253                pkt->xfer_mode, pkt->vdisk_block_size,
 254                pkt->max_xfer_size);
 255
 256         if (pkt->tag.stype == VIO_SUBTYPE_ACK) {
 257                 switch (pkt->vdisk_type) {
 258                 case VD_DISK_TYPE_DISK:
 259                 case VD_DISK_TYPE_SLICE:
 260                         break;
 261
 262                 default:
 263                         printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n",
 264                                vio->name, pkt->vdisk_type);
 265                         return -ECONNRESET;
 266                 }
 267
 268                 if (pkt->vdisk_block_size > port->vdisk_block_size) {
 269                         printk(KERN_ERR PFX "%s: BLOCK size increased "
 270                                "%u --> %u\n",
 271                                vio->name,
 272                                port->vdisk_block_size, pkt->vdisk_block_size);
 273                         return -ECONNRESET;
 274                 }
 275
 276                 port->operations = pkt->operations;
 277                 port->vdisk_type = pkt->vdisk_type;
 278                 if (vdc_version_supported(port, 1, 1)) {
 279                         port->vdisk_size = pkt->vdisk_size;
 280                         port->vdisk_mtype = pkt->vdisk_mtype;
 281                 }
 282                 if (pkt->max_xfer_size < port->max_xfer_size)
 283                         port->max_xfer_size = pkt->max_xfer_size;
 284                 port->vdisk_block_size = pkt->vdisk_block_size;
 285
 286                 port->vdisk_phys_blksz = VDC_DEFAULT_BLK_SIZE;
 287                 if (vdc_version_supported(port, 1, 2))
 288                         port->vdisk_phys_blksz = pkt->phys_block_size;
 289
 290                 return 0;
 291         } else {
 292                 printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name);
 293
 294                 return -ECONNRESET;
 295         }
 296 }
 297
 298 static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc)
 299 {
 300         int err = desc->status;
 301
 302         vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
 303 }
 304
 305 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
 306                         unsigned int index)
 307 {
 308         struct vio_disk_desc *desc = vio_dring_entry(dr, index);
 309         struct vdc_req_entry *rqe = &port->rq_arr[index];
 310         struct request *req;
 311
 312         if (unlikely(desc->hdr.state != VIO_DESC_DONE))
 313                 return;
 314
 315         ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
 316         desc->hdr.state = VIO_DESC_FREE;
 317         dr->cons = vio_dring_next(dr, index);
 318
 319         req = rqe->req;
 320         if (req == NULL) {
 321                 vdc_end_special(port, desc);
 322                 return;
 323         }
 324
 325         rqe->req = NULL;
 326
 327         blk_mq_end_request(req, desc->status ? BLK_STS_IOERR : 0);
 328
 329         vdc_blk_queue_start(port);
 330 }
 331
 332 static int vdc_ack(struct vdc_port *port, void *msgbuf)
 333 {
 334         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 335         struct vio_dring_data *pkt = msgbuf;
 336
 337         if (unlikely(pkt->dring_ident != dr->ident ||
 338                      pkt->start_idx != pkt->end_idx ||
 339                      pkt->start_idx >= VDC_TX_RING_SIZE))
 340                 return 0;
 341
 342         vdc_end_one(port, dr, pkt->start_idx);
 343
 344         return 0;
 345 }
 346
 347 static int vdc_nack(struct vdc_port *port, void *msgbuf)
 348 {
 349         /* XXX Implement me XXX */
 350         return 0;
 351 }
 352
 353 static void vdc_event(void *arg, int event)
 354 {
 355         struct vdc_port *port = arg;
 356         struct vio_driver_state *vio = &port->vio;
 357         unsigned long flags;
 358         int err;
 359
 360         spin_lock_irqsave(&vio->lock, flags);
 361
 362         if (unlikely(event == LDC_EVENT_RESET)) {
 363                 vio_link_state_change(vio, event);
 364                 queue_work(sunvdc_wq, &port->ldc_reset_work);
 365                 goto out;
 366         }
 367
 368         if (unlikely(event == LDC_EVENT_UP)) {
 369                 vio_link_state_change(vio, event);
 370                 goto out;
 371         }
 372
 373         if (unlikely(event != LDC_EVENT_DATA_READY)) {
 374                 pr_warn(PFX "Unexpected LDC event %d\n", event);
 375                 goto out;
 376         }
 377
 378         err = 0;
 379         while (1) {
 380                 union {
 381                         struct vio_msg_tag tag;
 382                         u64 raw[8];
 383                 } msgbuf;
 384
 385                 err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf));
 386                 if (unlikely(err < 0)) {
 387                         if (err == -ECONNRESET)
 388                                 vio_conn_reset(vio);
 389                         break;
 390                 }
 391                 if (err == 0)
 392                         break;
 393                 viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
 394                        msgbuf.tag.type,
 395                        msgbuf.tag.stype,
 396                        msgbuf.tag.stype_env,
 397                        msgbuf.tag.sid);
 398                 err = vio_validate_sid(vio, &msgbuf.tag);
 399                 if (err < 0)
 400                         break;
 401
 402                 if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) {
 403                         if (msgbuf.tag.stype == VIO_SUBTYPE_ACK)
 404                                 err = vdc_ack(port, &msgbuf);
 405                         else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK)
 406                                 err = vdc_nack(port, &msgbuf);
 407                         else
 408                                 err = vdc_handle_unknown(port, &msgbuf);
 409                 } else if (msgbuf.tag.type == VIO_TYPE_CTRL) {
 410                         err = vio_control_pkt_engine(vio, &msgbuf);
 411                 } else {
 412                         err = vdc_handle_unknown(port, &msgbuf);
 413                 }
 414                 if (err < 0)
 415                         break;
 416         }
 417         if (err < 0)
 418                 vdc_finish(&port->vio, err, WAITING_FOR_ANY);
 419 out:
 420         spin_unlock_irqrestore(&vio->lock, flags);
 421 }
 422
 423 static int __vdc_tx_trigger(struct vdc_port *port)
 424 {
 425         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 426         struct vio_dring_data hdr = {
 427                 .tag = {
 428                         .type           = VIO_TYPE_DATA,
 429                         .stype          = VIO_SUBTYPE_INFO,
 430                         .stype_env      = VIO_DRING_DATA,
 431                         .sid            = vio_send_sid(&port->vio),
 432                 },
 433                 .dring_ident            = dr->ident,
 434                 .start_idx              = dr->prod,
 435                 .end_idx                = dr->prod,
 436         };
 437         int err, delay;
 438         int retries = 0;
 439
 440         hdr.seq = dr->snd_nxt;
 441         delay = 1;
 442         do {
 443                 err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr));
 444                 if (err > 0) {
 445                         dr->snd_nxt++;
 446                         break;
 447                 }
 448                 udelay(delay);
 449                 if ((delay <<= 1) > 128)
 450                         delay = 128;
 451                 if (retries++ > VDC_MAX_RETRIES)
 452                         break;
 453         } while (err == -EAGAIN);
 454
 455         if (err == -ENOTCONN)
 456                 vdc_ldc_reset(port);
 457         return err;
 458 }
 459
 460 static int __send_request(struct request *req)
 461 {
 462         struct vdc_port *port = req->rq_disk->private_data;
 463         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 464         struct scatterlist sg[MAX_RING_COOKIES];
 465         struct vdc_req_entry *rqe;
 466         struct vio_disk_desc *desc;
 467         unsigned int map_perm;
 468         int nsg, err, i;
 469         u64 len;
 470         u8 op;
 471
 472         if (WARN_ON(port->ring_cookies > MAX_RING_COOKIES))
 473                 return -EINVAL;
 474
 475         map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 476
 477         if (rq_data_dir(req) == READ) {
 478                 map_perm |= LDC_MAP_W;
 479                 op = VD_OP_BREAD;
 480         } else {
 481                 map_perm |= LDC_MAP_R;
 482                 op = VD_OP_BWRITE;
 483         }
 484
 485         sg_init_table(sg, port->ring_cookies);
 486         nsg = blk_rq_map_sg(req->q, req, sg);
 487
 488         len = 0;
 489         for (i = 0; i < nsg; i++)
 490                 len += sg[i].length;
 491
 492         desc = vio_dring_cur(dr);
 493
 494         err = ldc_map_sg(port->vio.lp, sg, nsg,
 495                          desc->cookies, port->ring_cookies,
 496                          map_perm);
 497         if (err < 0) {
 498                 printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err);
 499                 return err;
 500         }
 501
 502         rqe = &port->rq_arr[dr->prod];
 503         rqe->req = req;
 504
 505         desc->hdr.ack = VIO_ACK_ENABLE;
 506         desc->req_id = port->req_id;
 507         desc->operation = op;
 508         if (port->vdisk_type == VD_DISK_TYPE_DISK) {
 509                 desc->slice = 0xff;
 510         } else {
 511                 desc->slice = 0;
 512         }
 513         desc->status = ~0;
 514         desc->offset = (blk_rq_pos(req) << 9) / port->vdisk_block_size;
 515         desc->size = len;
 516         desc->ncookies = err;
 517
 518         /* This has to be a non-SMP write barrier because we are writing
 519          * to memory which is shared with the peer LDOM.
 520          */
 521         wmb();
 522         desc->hdr.state = VIO_DESC_READY;
 523
 524         err = __vdc_tx_trigger(port);
 525         if (err < 0) {
 526                 printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err);
 527         } else {
 528                 port->req_id++;
 529                 dr->prod = vio_dring_next(dr, dr->prod);
 530         }
 531
 532         return err;
 533 }
 534
 535 static blk_status_t vdc_queue_rq(struct blk_mq_hw_ctx *hctx,
 536                                  const struct blk_mq_queue_data *bd)
 537 {
 538         struct vdc_port *port = hctx->queue->queuedata;
 539         struct vio_dring_state *dr;
 540         unsigned long flags;
 541
 542         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 543
 544         blk_mq_start_request(bd->rq);
 545
 546         spin_lock_irqsave(&port->vio.lock, flags);
 547
 548         /*
 549          * Doing drain, just end the request in error
 550          */
 551         if (unlikely(port->drain)) {
 552                 spin_unlock_irqrestore(&port->vio.lock, flags);
 553                 return BLK_STS_IOERR;
 554         }
 555
 556         if (unlikely(vdc_tx_dring_avail(dr) < 1)) {
 557                 spin_unlock_irqrestore(&port->vio.lock, flags);
 558                 blk_mq_stop_hw_queue(hctx);
 559                 return BLK_STS_DEV_RESOURCE;
 560         }
 561
 562         if (__send_request(bd->rq) < 0) {
 563                 spin_unlock_irqrestore(&port->vio.lock, flags);
 564                 return BLK_STS_IOERR;
 565         }
 566
 567         spin_unlock_irqrestore(&port->vio.lock, flags);
 568         return BLK_STS_OK;
 569 }
 570
 571 static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
 572 {
 573         struct vio_dring_state *dr;
 574         struct vio_completion comp;
 575         struct vio_disk_desc *desc;
 576         unsigned int map_perm;
 577         unsigned long flags;
 578         int op_len, err;
 579         void *req_buf;
 580
 581         if (!(((u64)1 << (u64)op) & port->operations))
 582                 return -EOPNOTSUPP;
 583
 584         switch (op) {
 585         case VD_OP_BREAD:
 586         case VD_OP_BWRITE:
 587         default:
 588                 return -EINVAL;
 589
 590         case VD_OP_FLUSH:
 591                 op_len = 0;
 592                 map_perm = 0;
 593                 break;
 594
 595         case VD_OP_GET_WCE:
 596                 op_len = sizeof(u32);
 597                 map_perm = LDC_MAP_W;
 598                 break;
 599
 600         case VD_OP_SET_WCE:
 601                 op_len = sizeof(u32);
 602                 map_perm = LDC_MAP_R;
 603                 break;
 604
 605         case VD_OP_GET_VTOC:
 606                 op_len = sizeof(struct vio_disk_vtoc);
 607                 map_perm = LDC_MAP_W;
 608                 break;
 609
 610         case VD_OP_SET_VTOC:
 611                 op_len = sizeof(struct vio_disk_vtoc);
 612                 map_perm = LDC_MAP_R;
 613                 break;
 614
 615         case VD_OP_GET_DISKGEOM:
 616                 op_len = sizeof(struct vio_disk_geom);
 617                 map_perm = LDC_MAP_W;
 618                 break;
 619
 620         case VD_OP_SET_DISKGEOM:
 621                 op_len = sizeof(struct vio_disk_geom);
 622                 map_perm = LDC_MAP_R;
 623                 break;
 624
 625         case VD_OP_SCSICMD:
 626                 op_len = 16;
 627                 map_perm = LDC_MAP_RW;
 628                 break;
 629
 630         case VD_OP_GET_DEVID:
 631                 op_len = sizeof(struct vio_disk_devid);
 632                 map_perm = LDC_MAP_W;
 633                 break;
 634
 635         case VD_OP_GET_EFI:
 636         case VD_OP_SET_EFI:
 637                 return -EOPNOTSUPP;
 638         }
 639
 640         map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO;
 641
 642         op_len = (op_len + 7) & ~7;
 643         req_buf = kzalloc(op_len, GFP_KERNEL);
 644         if (!req_buf)
 645                 return -ENOMEM;
 646
 647         if (len > op_len)
 648                 len = op_len;
 649
 650         if (map_perm & LDC_MAP_R)
 651                 memcpy(req_buf, buf, len);
 652
 653         spin_lock_irqsave(&port->vio.lock, flags);
 654
 655         dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 656
 657         /* XXX If we want to use this code generically we have to
 658          * XXX handle TX ring exhaustion etc.
 659          */
 660         desc = vio_dring_cur(dr);
 661
 662         err = ldc_map_single(port->vio.lp, req_buf, op_len,
 663                              desc->cookies, port->ring_cookies,
 664                              map_perm);
 665         if (err < 0) {
 666                 spin_unlock_irqrestore(&port->vio.lock, flags);
 667                 kfree(req_buf);
 668                 return err;
 669         }
 670
 671         init_completion(&comp.com);
 672         comp.waiting_for = WAITING_FOR_GEN_CMD;
 673         port->vio.cmp = &comp;
 674
 675         desc->hdr.ack = VIO_ACK_ENABLE;
 676         desc->req_id = port->req_id;
 677         desc->operation = op;
 678         desc->slice = 0;
 679         desc->status = ~0;
 680         desc->offset = 0;
 681         desc->size = op_len;
 682         desc->ncookies = err;
 683
 684         /* This has to be a non-SMP write barrier because we are writing
 685          * to memory which is shared with the peer LDOM.
 686          */
 687         wmb();
 688         desc->hdr.state = VIO_DESC_READY;
 689
 690         err = __vdc_tx_trigger(port);
 691         if (err >= 0) {
 692                 port->req_id++;
 693                 dr->prod = vio_dring_next(dr, dr->prod);
 694                 spin_unlock_irqrestore(&port->vio.lock, flags);
 695
 696                 wait_for_completion(&comp.com);
 697                 err = comp.err;
 698         } else {
 699                 port->vio.cmp = NULL;
 700                 spin_unlock_irqrestore(&port->vio.lock, flags);
 701         }
 702
 703         if (map_perm & LDC_MAP_W)
 704                 memcpy(buf, req_buf, len);
 705
 706         kfree(req_buf);
 707
 708         return err;
 709 }
 710
 711 static int vdc_alloc_tx_ring(struct vdc_port *port)
 712 {
 713         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 714         unsigned long len, entry_size;
 715         int ncookies;
 716         void *dring;
 717
 718         entry_size = sizeof(struct vio_disk_desc) +
 719                 (sizeof(struct ldc_trans_cookie) * port->ring_cookies);
 720         len = (VDC_TX_RING_SIZE * entry_size);
 721
 722         ncookies = VIO_MAX_RING_COOKIES;
 723         dring = ldc_alloc_exp_dring(port->vio.lp, len,
 724                                     dr->cookies, &ncookies,
 725                                     (LDC_MAP_SHADOW |
 726                                      LDC_MAP_DIRECT |
 727                                      LDC_MAP_RW));
 728         if (IS_ERR(dring))
 729                 return PTR_ERR(dring);
 730
 731         dr->base = dring;
 732         dr->entry_size = entry_size;
 733         dr->num_entries = VDC_TX_RING_SIZE;
 734         dr->prod = dr->cons = 0;
 735         dr->pending = VDC_TX_RING_SIZE;
 736         dr->ncookies = ncookies;
 737
 738         return 0;
 739 }
 740
 741 static void vdc_free_tx_ring(struct vdc_port *port)
 742 {
 743         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
 744
 745         if (dr->base) {
 746                 ldc_free_exp_dring(port->vio.lp, dr->base,
 747                                    (dr->entry_size * dr->num_entries),
 748                                    dr->cookies, dr->ncookies);
 749                 dr->base = NULL;
 750                 dr->entry_size = 0;
 751                 dr->num_entries = 0;
 752                 dr->pending = 0;
 753                 dr->ncookies = 0;
 754         }
 755 }
 756
 757 static int vdc_port_up(struct vdc_port *port)
 758 {
 759         struct vio_completion comp;
 760
 761         init_completion(&comp.com);
 762         comp.err = 0;
 763         comp.waiting_for = WAITING_FOR_LINK_UP;
 764         port->vio.cmp = &comp;
 765
 766         vio_port_up(&port->vio);
 767         wait_for_completion(&comp.com);
 768         return comp.err;
 769 }
 770
 771 static void vdc_port_down(struct vdc_port *port)
 772 {
 773         ldc_disconnect(port->vio.lp);
 774         ldc_unbind(port->vio.lp);
 775         vdc_free_tx_ring(port);
 776         vio_ldc_free(&port->vio);
 777 }
 778
 779 static const struct blk_mq_ops vdc_mq_ops = {
 780         .queue_rq       = vdc_queue_rq,
 781 };
 782
 783 static void cleanup_queue(struct request_queue *q)
 784 {
 785         struct vdc_port *port = q->queuedata;
 786
 787         blk_cleanup_queue(q);
 788         blk_mq_free_tag_set(&port->tag_set);
 789 }
 790
 791 static struct request_queue *init_queue(struct vdc_port *port)
 792 {
 793         struct request_queue *q;
 794
 795         q = blk_mq_init_sq_queue(&port->tag_set, &vdc_mq_ops, VDC_TX_RING_SIZE,
 796                                         BLK_MQ_F_SHOULD_MERGE);
 797         if (IS_ERR(q))
 798                 return q;
 799
 800         q->queuedata = port;
 801         return q;
 802 }
 803
 804 static int probe_disk(struct vdc_port *port)
 805 {
 806         struct request_queue *q;
 807         struct gendisk *g;
 808         int err;
 809
 810         err = vdc_port_up(port);
 811         if (err)
 812                 return err;
 813
 814         /* Using version 1.2 means vdisk_phys_blksz should be set unless the
 815          * disk is reserved by another system.
 816          */
 817         if (vdc_version_supported(port, 1, 2) && !port->vdisk_phys_blksz)
 818                 return -ENODEV;
 819
 820         if (vdc_version_supported(port, 1, 1)) {
 821                 /* vdisk_size should be set during the handshake, if it wasn't
 822                  * then the underlying disk is reserved by another system
 823                  */
 824                 if (port->vdisk_size == -1)
 825                         return -ENODEV;
 826         } else {
 827                 struct vio_disk_geom geom;
 828
 829                 err = generic_request(port, VD_OP_GET_DISKGEOM,
 830                                       &geom, sizeof(geom));
 831                 if (err < 0) {
 832                         printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
 833                                "error %d\n", err);
 834                         return err;
 835                 }
 836                 port->vdisk_size = ((u64)geom.num_cyl *
 837                                     (u64)geom.num_hd *
 838                                     (u64)geom.num_sec);
 839         }
 840
 841         q = init_queue(port);
 842         if (IS_ERR(q)) {
 843                 printk(KERN_ERR PFX "%s: Could not allocate queue.\n",
 844                        port->vio.name);
 845                 return PTR_ERR(q);
 846         }
 847         g = alloc_disk(1 << PARTITION_SHIFT);
 848         if (!g) {
 849                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
 850                        port->vio.name);
 851                 cleanup_queue(q);
 852                 return -ENOMEM;
 853         }
 854
 855         port->disk = g;
 856
 857         /* Each segment in a request is up to an aligned page in size. */
 858         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
 859         blk_queue_max_segment_size(q, PAGE_SIZE);
 860
 861         blk_queue_max_segments(q, port->ring_cookies);
 862         blk_queue_max_hw_sectors(q, port->max_xfer_size);
 863         g->major = vdc_major;
 864         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
 865         strcpy(g->disk_name, port->disk_name);
 866
 867         g->fops = &vdc_fops;
 868         g->queue = q;
 869         g->private_data = port;
 870
 871         set_capacity(g, port->vdisk_size);
 872
 873         if (vdc_version_supported(port, 1, 1)) {
 874                 switch (port->vdisk_mtype) {
 875                 case VD_MEDIA_TYPE_CD:
 876                         pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
 877                         g->flags |= GENHD_FL_CD;
 878                         g->flags |= GENHD_FL_REMOVABLE;
 879                         set_disk_ro(g, 1);
 880                         break;
 881
 882                 case VD_MEDIA_TYPE_DVD:
 883                         pr_info(PFX "Virtual DVD %s\n", port->disk_name);
 884                         g->flags |= GENHD_FL_CD;
 885                         g->flags |= GENHD_FL_REMOVABLE;
 886                         set_disk_ro(g, 1);
 887                         break;
 888
 889                 case VD_MEDIA_TYPE_FIXED:
 890                         pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
 891                         break;
 892                 }
 893         }
 894
 895         blk_queue_physical_block_size(q, port->vdisk_phys_blksz);
 896
 897         pr_info(PFX "%s: %u sectors (%u MB) protocol %d.%d\n",
 898                g->disk_name,
 899                port->vdisk_size, (port->vdisk_size >> (20 - 9)),
 900                port->vio.ver.major, port->vio.ver.minor);
 901
 902         device_add_disk(&port->vio.vdev->dev, g, NULL);
 903
 904         return 0;
 905 }
 906
 907 static struct ldc_channel_config vdc_ldc_cfg = {
 908         .event          = vdc_event,
 909         .mtu            = 64,
 910         .mode           = LDC_MODE_UNRELIABLE,
 911 };
 912
 913 static struct vio_driver_ops vdc_vio_ops = {
 914         .send_attr              = vdc_send_attr,
 915         .handle_attr            = vdc_handle_attr,
 916         .handshake_complete     = vdc_handshake_complete,
 917 };
 918
 919 static void print_version(void)
 920 {
 921         static int version_printed;
 922
 923         if (version_printed++ == 0)
 924                 printk(KERN_INFO "%s", version);
 925 }
 926
 927 struct vdc_check_port_data {
 928         int     dev_no;
 929         char    *type;
 930 };
 931
 932 static int vdc_device_probed(struct device *dev, void *arg)
 933 {
 934         struct vio_dev *vdev = to_vio_dev(dev);
 935         struct vdc_check_port_data *port_data;
 936
 937         port_data = (struct vdc_check_port_data *)arg;
 938
 939         if ((vdev->dev_no == port_data->dev_no) &&
 940             (!(strcmp((char *)&vdev->type, port_data->type))) &&
 941                 dev_get_drvdata(dev)) {
 942                 /* This device has already been configured
 943                  * by vdc_port_probe()
 944                  */
 945                 return 1;
 946         } else {
 947                 return 0;
 948         }
 949 }
 950
 951 /* Determine whether the VIO device is part of an mpgroup
 952  * by locating all the virtual-device-port nodes associated
 953  * with the parent virtual-device node for the VIO device
 954  * and checking whether any of these nodes are vdc-ports
 955  * which have already been configured.
 956  *
 957  * Returns true if this device is part of an mpgroup and has
 958  * already been probed.
 959  */
 960 static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
 961 {
 962         struct vdc_check_port_data port_data;
 963         struct device *dev;
 964
 965         port_data.dev_no = vdev->dev_no;
 966         port_data.type = (char *)&vdev->type;
 967
 968         dev = device_find_child(vdev->dev.parent, &port_data,
 969                                 vdc_device_probed);
 970
 971         if (dev)
 972                 return true;
 973
 974         return false;
 975 }
 976
 977 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 978 {
 979         struct mdesc_handle *hp;
 980         struct vdc_port *port;
 981         int err;
 982         const u64 *ldc_timeout;
 983
 984         print_version();
 985
 986         hp = mdesc_grab();
 987
 988         err = -ENODEV;
 989         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
 990                 printk(KERN_ERR PFX "Port id [%llu] too large.\n",
 991                        vdev->dev_no);
 992                 goto err_out_release_mdesc;
 993         }
 994
 995         /* Check if this device is part of an mpgroup */
 996         if (vdc_port_mpgroup_check(vdev)) {
 997                 printk(KERN_WARNING
 998                         "VIO: Ignoring extra vdisk port %s",
 999                         dev_name(&vdev->dev));
1000                 goto err_out_release_mdesc;
1001         }
1002
1003         port = kzalloc(sizeof(*port), GFP_KERNEL);
1004         err = -ENOMEM;
1005         if (!port) {
1006                 printk(KERN_ERR PFX "Cannot allocate vdc_port.\n");
1007                 goto err_out_release_mdesc;
1008         }
1009
1010         if (vdev->dev_no >= 26)
1011                 snprintf(port->disk_name, sizeof(port->disk_name),
1012                          VDCBLK_NAME "%c%c",
1013                          'a' + ((int)vdev->dev_no / 26) - 1,
1014                          'a' + ((int)vdev->dev_no % 26));
1015         else
1016                 snprintf(port->disk_name, sizeof(port->disk_name),
1017                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
1018         port->vdisk_size = -1;
1019
1020         /* Actual wall time may be double due to do_generic_file_read() doing
1021          * a readahead I/O first, and once that fails it will try to read a
1022          * single page.
1023          */
1024         ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
1025         port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
1026         INIT_DELAYED_WORK(&port->ldc_reset_timer_work, vdc_ldc_reset_timer_work);
1027         INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
1028
1029         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
1030                               vdc_versions, ARRAY_SIZE(vdc_versions),
1031                               &vdc_vio_ops, port->disk_name);
1032         if (err)
1033                 goto err_out_free_port;
1034
1035         port->vdisk_block_size = VDC_DEFAULT_BLK_SIZE;
1036         port->max_xfer_size = MAX_XFER_SIZE;
1037         port->ring_cookies = MAX_RING_COOKIES;
1038
1039         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1040         if (err)
1041                 goto err_out_free_port;
1042
1043         err = vdc_alloc_tx_ring(port);
1044         if (err)
1045                 goto err_out_free_ldc;
1046
1047         err = probe_disk(port);
1048         if (err)
1049                 goto err_out_free_tx_ring;
1050
1051         /* Note that the device driver_data is used to determine
1052          * whether the port has been probed.
1053          */
1054         dev_set_drvdata(&vdev->dev, port);
1055
1056         mdesc_release(hp);
1057
1058         return 0;
1059
1060 err_out_free_tx_ring:
1061         vdc_free_tx_ring(port);
1062
1063 err_out_free_ldc:
1064         vio_ldc_free(&port->vio);
1065
1066 err_out_free_port:
1067         kfree(port);
1068
1069 err_out_release_mdesc:
1070         mdesc_release(hp);
1071         return err;
1072 }
1073
1074 static int vdc_port_remove(struct vio_dev *vdev)
1075 {
1076         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
1077
1078         if (port) {
1079                 blk_mq_stop_hw_queues(port->disk->queue);
1080
1081                 flush_work(&port->ldc_reset_work);
1082                 cancel_delayed_work_sync(&port->ldc_reset_timer_work);
1083                 del_timer_sync(&port->vio.timer);
1084
1085                 del_gendisk(port->disk);
1086                 cleanup_queue(port->disk->queue);
1087                 put_disk(port->disk);
1088                 port->disk = NULL;
1089
1090                 vdc_free_tx_ring(port);
1091                 vio_ldc_free(&port->vio);
1092
1093                 dev_set_drvdata(&vdev->dev, NULL);
1094
1095                 kfree(port);
1096         }
1097         return 0;
1098 }
1099
1100 static void vdc_requeue_inflight(struct vdc_port *port)
1101 {
1102         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1103         u32 idx;
1104
1105         for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
1106                 struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
1107                 struct vdc_req_entry *rqe = &port->rq_arr[idx];
1108                 struct request *req;
1109
1110                 ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
1111                 desc->hdr.state = VIO_DESC_FREE;
1112                 dr->cons = vio_dring_next(dr, idx);
1113
1114                 req = rqe->req;
1115                 if (req == NULL) {
1116                         vdc_end_special(port, desc);
1117                         continue;
1118                 }
1119
1120                 rqe->req = NULL;
1121                 blk_mq_requeue_request(req, false);
1122         }
1123 }
1124
1125 static void vdc_queue_drain(struct vdc_port *port)
1126 {
1127         struct request_queue *q = port->disk->queue;
1128
1129         /*
1130          * Mark the queue as draining, then freeze/quiesce to ensure
1131          * that all existing requests are seen in ->queue_rq() and killed
1132          */
1133         port->drain = 1;
1134         spin_unlock_irq(&port->vio.lock);
1135
1136         blk_mq_freeze_queue(q);
1137         blk_mq_quiesce_queue(q);
1138
1139         spin_lock_irq(&port->vio.lock);
1140         port->drain = 0;
1141         blk_mq_unquiesce_queue(q);
1142         blk_mq_unfreeze_queue(q);
1143 }
1144
1145 static void vdc_ldc_reset_timer_work(struct work_struct *work)
1146 {
1147         struct vdc_port *port;
1148         struct vio_driver_state *vio;
1149
1150         port = container_of(work, struct vdc_port, ldc_reset_timer_work.work);
1151         vio = &port->vio;
1152
1153         spin_lock_irq(&vio->lock);
1154         if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
1155                 pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
1156                         port->disk_name, port->ldc_timeout);
1157                 vdc_queue_drain(port);
1158                 vdc_blk_queue_start(port);
1159         }
1160         spin_unlock_irq(&vio->lock);
1161 }
1162
1163 static void vdc_ldc_reset_work(struct work_struct *work)
1164 {
1165         struct vdc_port *port;
1166         struct vio_driver_state *vio;
1167         unsigned long flags;
1168
1169         port = container_of(work, struct vdc_port, ldc_reset_work);
1170         vio = &port->vio;
1171
1172         spin_lock_irqsave(&vio->lock, flags);
1173         vdc_ldc_reset(port);
1174         spin_unlock_irqrestore(&vio->lock, flags);
1175 }
1176
1177 static void vdc_ldc_reset(struct vdc_port *port)
1178 {
1179         int err;
1180
1181         assert_spin_locked(&port->vio.lock);
1182
1183         pr_warn(PFX "%s ldc link reset\n", port->disk_name);
1184         blk_mq_stop_hw_queues(port->disk->queue);
1185         vdc_requeue_inflight(port);
1186         vdc_port_down(port);
1187
1188         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1189         if (err) {
1190                 pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
1191                 return;
1192         }
1193
1194         err = vdc_alloc_tx_ring(port);
1195         if (err) {
1196                 pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
1197                 goto err_free_ldc;
1198         }
1199
1200         if (port->ldc_timeout)
1201                 mod_delayed_work(system_wq, &port->ldc_reset_timer_work,
1202                           round_jiffies(jiffies + HZ * port->ldc_timeout));
1203         mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
1204         return;
1205
1206 err_free_ldc:
1207         vio_ldc_free(&port->vio);
1208 }
1209
1210 static const struct vio_device_id vdc_port_match[] = {
1211         {
1212                 .type = "vdc-port",
1213         },
1214         {},
1215 };
1216 MODULE_DEVICE_TABLE(vio, vdc_port_match);
1217
1218 static struct vio_driver vdc_port_driver = {
1219         .id_table       = vdc_port_match,
1220         .probe          = vdc_port_probe,
1221         .remove         = vdc_port_remove,
1222         .name           = "vdc_port",
1223 };
1224
1225 static int __init vdc_init(void)
1226 {
1227         int err;
1228
1229         sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
1230         if (!sunvdc_wq)
1231                 return -ENOMEM;
1232
1233         err = register_blkdev(0, VDCBLK_NAME);
1234         if (err < 0)
1235                 goto out_free_wq;
1236
1237         vdc_major = err;
1238
1239         err = vio_register_driver(&vdc_port_driver);
1240         if (err)
1241                 goto out_unregister_blkdev;
1242
1243         return 0;
1244
1245 out_unregister_blkdev:
1246         unregister_blkdev(vdc_major, VDCBLK_NAME);
1247         vdc_major = 0;
1248
1249 out_free_wq:
1250         destroy_workqueue(sunvdc_wq);
1251         return err;
1252 }
1253
1254 static void __exit vdc_exit(void)
1255 {
1256         vio_unregister_driver(&vdc_port_driver);
1257         unregister_blkdev(vdc_major, VDCBLK_NAME);
1258         destroy_workqueue(sunvdc_wq);
1259 }
1260
1261 module_init(vdc_init);
1262 module_exit(vdc_exit);