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 int probe_disk(struct vdc_port *port)
 784 {
 785         struct request_queue *q;
 786         struct gendisk *g;
 787         int err;
 788
 789         err = vdc_port_up(port);
 790         if (err)
 791                 return err;
 792
 793         /* Using version 1.2 means vdisk_phys_blksz should be set unless the
 794          * disk is reserved by another system.
 795          */
 796         if (vdc_version_supported(port, 1, 2) && !port->vdisk_phys_blksz)
 797                 return -ENODEV;
 798
 799         if (vdc_version_supported(port, 1, 1)) {
 800                 /* vdisk_size should be set during the handshake, if it wasn't
 801                  * then the underlying disk is reserved by another system
 802                  */
 803                 if (port->vdisk_size == -1)
 804                         return -ENODEV;
 805         } else {
 806                 struct vio_disk_geom geom;
 807
 808                 err = generic_request(port, VD_OP_GET_DISKGEOM,
 809                                       &geom, sizeof(geom));
 810                 if (err < 0) {
 811                         printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns "
 812                                "error %d\n", err);
 813                         return err;
 814                 }
 815                 port->vdisk_size = ((u64)geom.num_cyl *
 816                                     (u64)geom.num_hd *
 817                                     (u64)geom.num_sec);
 818         }
 819
 820         err = blk_mq_alloc_sq_tag_set(&port->tag_set, &vdc_mq_ops,
 821                         VDC_TX_RING_SIZE, BLK_MQ_F_SHOULD_MERGE);
 822         if (err)
 823                 return err;
 824
 825         g = blk_mq_alloc_disk(&port->tag_set, port);
 826         if (IS_ERR(g)) {
 827                 printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n",
 828                        port->vio.name);
 829                 blk_mq_free_tag_set(&port->tag_set);
 830                 return PTR_ERR(g);
 831         }
 832
 833         port->disk = g;
 834         q = g->queue;
 835
 836         /* Each segment in a request is up to an aligned page in size. */
 837         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
 838         blk_queue_max_segment_size(q, PAGE_SIZE);
 839
 840         blk_queue_max_segments(q, port->ring_cookies);
 841         blk_queue_max_hw_sectors(q, port->max_xfer_size);
 842         g->major = vdc_major;
 843         g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT;
 844         g->minors = 1 << PARTITION_SHIFT;
 845         strcpy(g->disk_name, port->disk_name);
 846
 847         g->fops = &vdc_fops;
 848         g->queue = q;
 849         g->private_data = port;
 850
 851         set_capacity(g, port->vdisk_size);
 852
 853         if (vdc_version_supported(port, 1, 1)) {
 854                 switch (port->vdisk_mtype) {
 855                 case VD_MEDIA_TYPE_CD:
 856                         pr_info(PFX "Virtual CDROM %s\n", port->disk_name);
 857                         g->flags |= GENHD_FL_CD;
 858                         g->flags |= GENHD_FL_REMOVABLE;
 859                         set_disk_ro(g, 1);
 860                         break;
 861
 862                 case VD_MEDIA_TYPE_DVD:
 863                         pr_info(PFX "Virtual DVD %s\n", port->disk_name);
 864                         g->flags |= GENHD_FL_CD;
 865                         g->flags |= GENHD_FL_REMOVABLE;
 866                         set_disk_ro(g, 1);
 867                         break;
 868
 869                 case VD_MEDIA_TYPE_FIXED:
 870                         pr_info(PFX "Virtual Hard disk %s\n", port->disk_name);
 871                         break;
 872                 }
 873         }
 874
 875         blk_queue_physical_block_size(q, port->vdisk_phys_blksz);
 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         device_add_disk(&port->vio.vdev->dev, g, NULL);
 883
 884         return 0;
 885 }
 886
 887 static struct ldc_channel_config vdc_ldc_cfg = {
 888         .event          = vdc_event,
 889         .mtu            = 64,
 890         .mode           = LDC_MODE_UNRELIABLE,
 891 };
 892
 893 static struct vio_driver_ops vdc_vio_ops = {
 894         .send_attr              = vdc_send_attr,
 895         .handle_attr            = vdc_handle_attr,
 896         .handshake_complete     = vdc_handshake_complete,
 897 };
 898
 899 static void print_version(void)
 900 {
 901         static int version_printed;
 902
 903         if (version_printed++ == 0)
 904                 printk(KERN_INFO "%s", version);
 905 }
 906
 907 struct vdc_check_port_data {
 908         int     dev_no;
 909         char    *type;
 910 };
 911
 912 static int vdc_device_probed(struct device *dev, void *arg)
 913 {
 914         struct vio_dev *vdev = to_vio_dev(dev);
 915         struct vdc_check_port_data *port_data;
 916
 917         port_data = (struct vdc_check_port_data *)arg;
 918
 919         if ((vdev->dev_no == port_data->dev_no) &&
 920             (!(strcmp((char *)&vdev->type, port_data->type))) &&
 921                 dev_get_drvdata(dev)) {
 922                 /* This device has already been configured
 923                  * by vdc_port_probe()
 924                  */
 925                 return 1;
 926         } else {
 927                 return 0;
 928         }
 929 }
 930
 931 /* Determine whether the VIO device is part of an mpgroup
 932  * by locating all the virtual-device-port nodes associated
 933  * with the parent virtual-device node for the VIO device
 934  * and checking whether any of these nodes are vdc-ports
 935  * which have already been configured.
 936  *
 937  * Returns true if this device is part of an mpgroup and has
 938  * already been probed.
 939  */
 940 static bool vdc_port_mpgroup_check(struct vio_dev *vdev)
 941 {
 942         struct vdc_check_port_data port_data;
 943         struct device *dev;
 944
 945         port_data.dev_no = vdev->dev_no;
 946         port_data.type = (char *)&vdev->type;
 947
 948         dev = device_find_child(vdev->dev.parent, &port_data,
 949                                 vdc_device_probed);
 950
 951         if (dev)
 952                 return true;
 953
 954         return false;
 955 }
 956
 957 static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
 958 {
 959         struct mdesc_handle *hp;
 960         struct vdc_port *port;
 961         int err;
 962         const u64 *ldc_timeout;
 963
 964         print_version();
 965
 966         hp = mdesc_grab();
 967
 968         err = -ENODEV;
 969         if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) {
 970                 printk(KERN_ERR PFX "Port id [%llu] too large.\n",
 971                        vdev->dev_no);
 972                 goto err_out_release_mdesc;
 973         }
 974
 975         /* Check if this device is part of an mpgroup */
 976         if (vdc_port_mpgroup_check(vdev)) {
 977                 printk(KERN_WARNING
 978                         "VIO: Ignoring extra vdisk port %s",
 979                         dev_name(&vdev->dev));
 980                 goto err_out_release_mdesc;
 981         }
 982
 983         port = kzalloc(sizeof(*port), GFP_KERNEL);
 984         if (!port) {
 985                 err = -ENOMEM;
 986                 goto err_out_release_mdesc;
 987         }
 988
 989         if (vdev->dev_no >= 26)
 990                 snprintf(port->disk_name, sizeof(port->disk_name),
 991                          VDCBLK_NAME "%c%c",
 992                          'a' + ((int)vdev->dev_no / 26) - 1,
 993                          'a' + ((int)vdev->dev_no % 26));
 994         else
 995                 snprintf(port->disk_name, sizeof(port->disk_name),
 996                          VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
 997         port->vdisk_size = -1;
 998
 999         /* Actual wall time may be double due to do_generic_file_read() doing
1000          * a readahead I/O first, and once that fails it will try to read a
1001          * single page.
1002          */
1003         ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
1004         port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
1005         INIT_DELAYED_WORK(&port->ldc_reset_timer_work, vdc_ldc_reset_timer_work);
1006         INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
1007
1008         err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
1009                               vdc_versions, ARRAY_SIZE(vdc_versions),
1010                               &vdc_vio_ops, port->disk_name);
1011         if (err)
1012                 goto err_out_free_port;
1013
1014         port->vdisk_block_size = VDC_DEFAULT_BLK_SIZE;
1015         port->max_xfer_size = MAX_XFER_SIZE;
1016         port->ring_cookies = MAX_RING_COOKIES;
1017
1018         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1019         if (err)
1020                 goto err_out_free_port;
1021
1022         err = vdc_alloc_tx_ring(port);
1023         if (err)
1024                 goto err_out_free_ldc;
1025
1026         err = probe_disk(port);
1027         if (err)
1028                 goto err_out_free_tx_ring;
1029
1030         /* Note that the device driver_data is used to determine
1031          * whether the port has been probed.
1032          */
1033         dev_set_drvdata(&vdev->dev, port);
1034
1035         mdesc_release(hp);
1036
1037         return 0;
1038
1039 err_out_free_tx_ring:
1040         vdc_free_tx_ring(port);
1041
1042 err_out_free_ldc:
1043         vio_ldc_free(&port->vio);
1044
1045 err_out_free_port:
1046         kfree(port);
1047
1048 err_out_release_mdesc:
1049         mdesc_release(hp);
1050         return err;
1051 }
1052
1053 static void vdc_port_remove(struct vio_dev *vdev)
1054 {
1055         struct vdc_port *port = dev_get_drvdata(&vdev->dev);
1056
1057         if (port) {
1058                 blk_mq_stop_hw_queues(port->disk->queue);
1059
1060                 flush_work(&port->ldc_reset_work);
1061                 cancel_delayed_work_sync(&port->ldc_reset_timer_work);
1062                 del_timer_sync(&port->vio.timer);
1063
1064                 del_gendisk(port->disk);
1065                 blk_cleanup_disk(port->disk);
1066                 blk_mq_free_tag_set(&port->tag_set);
1067
1068                 vdc_free_tx_ring(port);
1069                 vio_ldc_free(&port->vio);
1070
1071                 dev_set_drvdata(&vdev->dev, NULL);
1072
1073                 kfree(port);
1074         }
1075 }
1076
1077 static void vdc_requeue_inflight(struct vdc_port *port)
1078 {
1079         struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
1080         u32 idx;
1081
1082         for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
1083                 struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
1084                 struct vdc_req_entry *rqe = &port->rq_arr[idx];
1085                 struct request *req;
1086
1087                 ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
1088                 desc->hdr.state = VIO_DESC_FREE;
1089                 dr->cons = vio_dring_next(dr, idx);
1090
1091                 req = rqe->req;
1092                 if (req == NULL) {
1093                         vdc_end_special(port, desc);
1094                         continue;
1095                 }
1096
1097                 rqe->req = NULL;
1098                 blk_mq_requeue_request(req, false);
1099         }
1100 }
1101
1102 static void vdc_queue_drain(struct vdc_port *port)
1103 {
1104         struct request_queue *q = port->disk->queue;
1105
1106         /*
1107          * Mark the queue as draining, then freeze/quiesce to ensure
1108          * that all existing requests are seen in ->queue_rq() and killed
1109          */
1110         port->drain = 1;
1111         spin_unlock_irq(&port->vio.lock);
1112
1113         blk_mq_freeze_queue(q);
1114         blk_mq_quiesce_queue(q);
1115
1116         spin_lock_irq(&port->vio.lock);
1117         port->drain = 0;
1118         blk_mq_unquiesce_queue(q);
1119         blk_mq_unfreeze_queue(q);
1120 }
1121
1122 static void vdc_ldc_reset_timer_work(struct work_struct *work)
1123 {
1124         struct vdc_port *port;
1125         struct vio_driver_state *vio;
1126
1127         port = container_of(work, struct vdc_port, ldc_reset_timer_work.work);
1128         vio = &port->vio;
1129
1130         spin_lock_irq(&vio->lock);
1131         if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
1132                 pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
1133                         port->disk_name, port->ldc_timeout);
1134                 vdc_queue_drain(port);
1135                 vdc_blk_queue_start(port);
1136         }
1137         spin_unlock_irq(&vio->lock);
1138 }
1139
1140 static void vdc_ldc_reset_work(struct work_struct *work)
1141 {
1142         struct vdc_port *port;
1143         struct vio_driver_state *vio;
1144         unsigned long flags;
1145
1146         port = container_of(work, struct vdc_port, ldc_reset_work);
1147         vio = &port->vio;
1148
1149         spin_lock_irqsave(&vio->lock, flags);
1150         vdc_ldc_reset(port);
1151         spin_unlock_irqrestore(&vio->lock, flags);
1152 }
1153
1154 static void vdc_ldc_reset(struct vdc_port *port)
1155 {
1156         int err;
1157
1158         assert_spin_locked(&port->vio.lock);
1159
1160         pr_warn(PFX "%s ldc link reset\n", port->disk_name);
1161         blk_mq_stop_hw_queues(port->disk->queue);
1162         vdc_requeue_inflight(port);
1163         vdc_port_down(port);
1164
1165         err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
1166         if (err) {
1167                 pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
1168                 return;
1169         }
1170
1171         err = vdc_alloc_tx_ring(port);
1172         if (err) {
1173                 pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
1174                 goto err_free_ldc;
1175         }
1176
1177         if (port->ldc_timeout)
1178                 mod_delayed_work(system_wq, &port->ldc_reset_timer_work,
1179                           round_jiffies(jiffies + HZ * port->ldc_timeout));
1180         mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
1181         return;
1182
1183 err_free_ldc:
1184         vio_ldc_free(&port->vio);
1185 }
1186
1187 static const struct vio_device_id vdc_port_match[] = {
1188         {
1189                 .type = "vdc-port",
1190         },
1191         {},
1192 };
1193 MODULE_DEVICE_TABLE(vio, vdc_port_match);
1194
1195 static struct vio_driver vdc_port_driver = {
1196         .id_table       = vdc_port_match,
1197         .probe          = vdc_port_probe,
1198         .remove         = vdc_port_remove,
1199         .name           = "vdc_port",
1200 };
1201
1202 static int __init vdc_init(void)
1203 {
1204         int err;
1205
1206         sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
1207         if (!sunvdc_wq)
1208                 return -ENOMEM;
1209
1210         err = register_blkdev(0, VDCBLK_NAME);
1211         if (err < 0)
1212                 goto out_free_wq;
1213
1214         vdc_major = err;
1215
1216         err = vio_register_driver(&vdc_port_driver);
1217         if (err)
1218                 goto out_unregister_blkdev;
1219
1220         return 0;
1221
1222 out_unregister_blkdev:
1223         unregister_blkdev(vdc_major, VDCBLK_NAME);
1224         vdc_major = 0;
1225
1226 out_free_wq:
1227         destroy_workqueue(sunvdc_wq);
1228         return err;
1229 }
1230
1231 static void __exit vdc_exit(void)
1232 {
1233         vio_unregister_driver(&vdc_port_driver);
1234         unregister_blkdev(vdc_major, VDCBLK_NAME);
1235         destroy_workqueue(sunvdc_wq);
1236 }
1237
1238 module_init(vdc_init);
1239 module_exit(vdc_exit);