drivers/scsi/virtio_scsi.c

   1 /*
   2  * Virtio SCSI HBA driver
   3  *
   4  * Copyright IBM Corp. 2010
   5  * Copyright Red Hat, Inc. 2011
   6  *
   7  * Authors:
   8  *  Stefan Hajnoczi   <stefanha@linux.vnet.ibm.com>
   9  *  Paolo Bonzini   <pbonzini@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  12  * See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/slab.h>
  18 #include <linux/mempool.h>
  19 #include <linux/virtio.h>
  20 #include <linux/virtio_ids.h>
  21 #include <linux/virtio_config.h>
  22 #include <linux/virtio_scsi.h>
  23 #include <scsi/scsi_host.h>
  24 #include <scsi/scsi_device.h>
  25 #include <scsi/scsi_cmnd.h>
  26
  27 #define VIRTIO_SCSI_MEMPOOL_SZ 64
  28 #define VIRTIO_SCSI_EVENT_LEN 8
  29
  30 /* Command queue element */
  31 struct virtio_scsi_cmd {
  32         struct scsi_cmnd *sc;
  33         struct completion *comp;
  34         union {
  35                 struct virtio_scsi_cmd_req       cmd;
  36                 struct virtio_scsi_ctrl_tmf_req  tmf;
  37                 struct virtio_scsi_ctrl_an_req   an;
  38         } req;
  39         union {
  40                 struct virtio_scsi_cmd_resp      cmd;
  41                 struct virtio_scsi_ctrl_tmf_resp tmf;
  42                 struct virtio_scsi_ctrl_an_resp  an;
  43                 struct virtio_scsi_event         evt;
  44         } resp;
  45 } ____cacheline_aligned_in_smp;
  46
  47 struct virtio_scsi_event_node {
  48         struct virtio_scsi *vscsi;
  49         struct virtio_scsi_event event;
  50         struct work_struct work;
  51 };
  52
  53 struct virtio_scsi_vq {
  54         /* Protects vq */
  55         spinlock_t vq_lock;
  56
  57         struct virtqueue *vq;
  58 };
  59
  60 /* Per-target queue state */
  61 struct virtio_scsi_target_state {
  62         /* Protects sg.  Lock hierarchy is tgt_lock -> vq_lock.  */
  63         spinlock_t tgt_lock;
  64
  65         /* For sglist construction when adding commands to the virtqueue.  */
  66         struct scatterlist sg[];
  67 };
  68
  69 /* Driver instance state */
  70 struct virtio_scsi {
  71         struct virtio_device *vdev;
  72
  73         struct virtio_scsi_vq ctrl_vq;
  74         struct virtio_scsi_vq event_vq;
  75         struct virtio_scsi_vq req_vq;
  76
  77         /* Get some buffers ready for event vq */
  78         struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
  79
  80         struct virtio_scsi_target_state *tgt[];
  81 };
  82
  83 static struct kmem_cache *virtscsi_cmd_cache;
  84 static mempool_t *virtscsi_cmd_pool;
  85
  86 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
  87 {
  88         return vdev->priv;
  89 }
  90
  91 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
  92 {
  93         if (!resid)
  94                 return;
  95
  96         if (!scsi_bidi_cmnd(sc)) {
  97                 scsi_set_resid(sc, resid);
  98                 return;
  99         }
 100
 101         scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
 102         scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
 103 }
 104
 105 /**
 106  * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
 107  *
 108  * Called with vq_lock held.
 109  */
 110 static void virtscsi_complete_cmd(void *buf)
 111 {
 112         struct virtio_scsi_cmd *cmd = buf;
 113         struct scsi_cmnd *sc = cmd->sc;
 114         struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
 115
 116         dev_dbg(&sc->device->sdev_gendev,
 117                 "cmd %p response %u status %#02x sense_len %u\n",
 118                 sc, resp->response, resp->status, resp->sense_len);
 119
 120         sc->result = resp->status;
 121         virtscsi_compute_resid(sc, resp->resid);
 122         switch (resp->response) {
 123         case VIRTIO_SCSI_S_OK:
 124                 set_host_byte(sc, DID_OK);
 125                 break;
 126         case VIRTIO_SCSI_S_OVERRUN:
 127                 set_host_byte(sc, DID_ERROR);
 128                 break;
 129         case VIRTIO_SCSI_S_ABORTED:
 130                 set_host_byte(sc, DID_ABORT);
 131                 break;
 132         case VIRTIO_SCSI_S_BAD_TARGET:
 133                 set_host_byte(sc, DID_BAD_TARGET);
 134                 break;
 135         case VIRTIO_SCSI_S_RESET:
 136                 set_host_byte(sc, DID_RESET);
 137                 break;
 138         case VIRTIO_SCSI_S_BUSY:
 139                 set_host_byte(sc, DID_BUS_BUSY);
 140                 break;
 141         case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
 142                 set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
 143                 break;
 144         case VIRTIO_SCSI_S_TARGET_FAILURE:
 145                 set_host_byte(sc, DID_TARGET_FAILURE);
 146                 break;
 147         case VIRTIO_SCSI_S_NEXUS_FAILURE:
 148                 set_host_byte(sc, DID_NEXUS_FAILURE);
 149                 break;
 150         default:
 151                 scmd_printk(KERN_WARNING, sc, "Unknown response %d",
 152                             resp->response);
 153                 /* fall through */
 154         case VIRTIO_SCSI_S_FAILURE:
 155                 set_host_byte(sc, DID_ERROR);
 156                 break;
 157         }
 158
 159         WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE);
 160         if (sc->sense_buffer) {
 161                 memcpy(sc->sense_buffer, resp->sense,
 162                        min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
 163                 if (resp->sense_len)
 164                         set_driver_byte(sc, DRIVER_SENSE);
 165         }
 166
 167         mempool_free(cmd, virtscsi_cmd_pool);
 168         sc->scsi_done(sc);
 169 }
 170
 171 static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
 172 {
 173         void *buf;
 174         unsigned int len;
 175
 176         do {
 177                 virtqueue_disable_cb(vq);
 178                 while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
 179                         fn(buf);
 180         } while (!virtqueue_enable_cb(vq));
 181 }
 182
 183 static void virtscsi_req_done(struct virtqueue *vq)
 184 {
 185         struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
 186         struct virtio_scsi *vscsi = shost_priv(sh);
 187         unsigned long flags;
 188
 189         spin_lock_irqsave(&vscsi->req_vq.vq_lock, flags);
 190         virtscsi_vq_done(vq, virtscsi_complete_cmd);
 191         spin_unlock_irqrestore(&vscsi->req_vq.vq_lock, flags);
 192 };
 193
 194 static void virtscsi_complete_free(void *buf)
 195 {
 196         struct virtio_scsi_cmd *cmd = buf;
 197
 198         if (cmd->comp)
 199                 complete_all(cmd->comp);
 200         else
 201                 mempool_free(cmd, virtscsi_cmd_pool);
 202 }
 203
 204 static void virtscsi_ctrl_done(struct virtqueue *vq)
 205 {
 206         struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
 207         struct virtio_scsi *vscsi = shost_priv(sh);
 208         unsigned long flags;
 209
 210         spin_lock_irqsave(&vscsi->ctrl_vq.vq_lock, flags);
 211         virtscsi_vq_done(vq, virtscsi_complete_free);
 212         spin_unlock_irqrestore(&vscsi->ctrl_vq.vq_lock, flags);
 213 };
 214
 215 static int virtscsi_kick_event(struct virtio_scsi *vscsi,
 216                                struct virtio_scsi_event_node *event_node)
 217 {
 218         int ret;
 219         struct scatterlist sg;
 220         unsigned long flags;
 221
 222         sg_set_buf(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
 223
 224         spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
 225
 226         ret = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node, GFP_ATOMIC);
 227         if (ret >= 0)
 228                 virtqueue_kick(vscsi->event_vq.vq);
 229
 230         spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
 231
 232         return ret;
 233 }
 234
 235 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
 236 {
 237         int i;
 238
 239         for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
 240                 vscsi->event_list[i].vscsi = vscsi;
 241                 virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
 242         }
 243
 244         return 0;
 245 }
 246
 247 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
 248 {
 249         int i;
 250
 251         for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
 252                 cancel_work_sync(&vscsi->event_list[i].work);
 253 }
 254
 255 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
 256                                                 struct virtio_scsi_event *event)
 257 {
 258         struct scsi_device *sdev;
 259         struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
 260         unsigned int target = event->lun[1];
 261         unsigned int lun = (event->lun[2] << 8) | event->lun[3];
 262
 263         switch (event->reason) {
 264         case VIRTIO_SCSI_EVT_RESET_RESCAN:
 265                 scsi_add_device(shost, 0, target, lun);
 266                 break;
 267         case VIRTIO_SCSI_EVT_RESET_REMOVED:
 268                 sdev = scsi_device_lookup(shost, 0, target, lun);
 269                 if (sdev) {
 270                         scsi_remove_device(sdev);
 271                         scsi_device_put(sdev);
 272                 } else {
 273                         pr_err("SCSI device %d 0 %d %d not found\n",
 274                                 shost->host_no, target, lun);
 275                 }
 276                 break;
 277         default:
 278                 pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
 279         }
 280 }
 281
 282 static void virtscsi_handle_event(struct work_struct *work)
 283 {
 284         struct virtio_scsi_event_node *event_node =
 285                 container_of(work, struct virtio_scsi_event_node, work);
 286         struct virtio_scsi *vscsi = event_node->vscsi;
 287         struct virtio_scsi_event *event = &event_node->event;
 288
 289         if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
 290                 event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
 291                 scsi_scan_host(virtio_scsi_host(vscsi->vdev));
 292         }
 293
 294         switch (event->event) {
 295         case VIRTIO_SCSI_T_NO_EVENT:
 296                 break;
 297         case VIRTIO_SCSI_T_TRANSPORT_RESET:
 298                 virtscsi_handle_transport_reset(vscsi, event);
 299                 break;
 300         default:
 301                 pr_err("Unsupport virtio scsi event %x\n", event->event);
 302         }
 303         virtscsi_kick_event(vscsi, event_node);
 304 }
 305
 306 static void virtscsi_complete_event(void *buf)
 307 {
 308         struct virtio_scsi_event_node *event_node = buf;
 309
 310         INIT_WORK(&event_node->work, virtscsi_handle_event);
 311         schedule_work(&event_node->work);
 312 }
 313
 314 static void virtscsi_event_done(struct virtqueue *vq)
 315 {
 316         struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
 317         struct virtio_scsi *vscsi = shost_priv(sh);
 318         unsigned long flags;
 319
 320         spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
 321         virtscsi_vq_done(vq, virtscsi_complete_event);
 322         spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
 323 };
 324
 325 static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
 326                              struct scsi_data_buffer *sdb)
 327 {
 328         struct sg_table *table = &sdb->table;
 329         struct scatterlist *sg_elem;
 330         unsigned int idx = *p_idx;
 331         int i;
 332
 333         for_each_sg(table->sgl, sg_elem, table->nents, i)
 334                 sg_set_buf(&sg[idx++], sg_virt(sg_elem), sg_elem->length);
 335
 336         *p_idx = idx;
 337 }
 338
 339 /**
 340  * virtscsi_map_cmd - map a scsi_cmd to a virtqueue scatterlist
 341  * @vscsi       : virtio_scsi state
 342  * @cmd         : command structure
 343  * @out_num     : number of read-only elements
 344  * @in_num      : number of write-only elements
 345  * @req_size    : size of the request buffer
 346  * @resp_size   : size of the response buffer
 347  *
 348  * Called with tgt_lock held.
 349  */
 350 static void virtscsi_map_cmd(struct virtio_scsi_target_state *tgt,
 351                              struct virtio_scsi_cmd *cmd,
 352                              unsigned *out_num, unsigned *in_num,
 353                              size_t req_size, size_t resp_size)
 354 {
 355         struct scsi_cmnd *sc = cmd->sc;
 356         struct scatterlist *sg = tgt->sg;
 357         unsigned int idx = 0;
 358
 359         /* Request header.  */
 360         sg_set_buf(&sg[idx++], &cmd->req, req_size);
 361
 362         /* Data-out buffer.  */
 363         if (sc && sc->sc_data_direction != DMA_FROM_DEVICE)
 364                 virtscsi_map_sgl(sg, &idx, scsi_out(sc));
 365
 366         *out_num = idx;
 367
 368         /* Response header.  */
 369         sg_set_buf(&sg[idx++], &cmd->resp, resp_size);
 370
 371         /* Data-in buffer */
 372         if (sc && sc->sc_data_direction != DMA_TO_DEVICE)
 373                 virtscsi_map_sgl(sg, &idx, scsi_in(sc));
 374
 375         *in_num = idx - *out_num;
 376 }
 377
 378 static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
 379                              struct virtio_scsi_vq *vq,
 380                              struct virtio_scsi_cmd *cmd,
 381                              size_t req_size, size_t resp_size, gfp_t gfp)
 382 {
 383         unsigned int out_num, in_num;
 384         unsigned long flags;
 385         int ret;
 386
 387         spin_lock_irqsave(&tgt->tgt_lock, flags);
 388         virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
 389
 390         spin_lock(&vq->vq_lock);
 391         ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
 392         spin_unlock(&tgt->tgt_lock);
 393         if (ret >= 0)
 394                 ret = virtqueue_kick_prepare(vq->vq);
 395
 396         spin_unlock_irqrestore(&vq->vq_lock, flags);
 397
 398         if (ret > 0)
 399                 virtqueue_notify(vq->vq);
 400         return ret;
 401 }
 402
 403 static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
 404 {
 405         struct virtio_scsi *vscsi = shost_priv(sh);
 406         struct virtio_scsi_target_state *tgt = vscsi->tgt[sc->device->id];
 407         struct virtio_scsi_cmd *cmd;
 408         int ret;
 409
 410         struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
 411         BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
 412
 413         /* TODO: check feature bit and fail if unsupported?  */
 414         BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
 415
 416         dev_dbg(&sc->device->sdev_gendev,
 417                 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
 418
 419         ret = SCSI_MLQUEUE_HOST_BUSY;
 420         cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC);
 421         if (!cmd)
 422                 goto out;
 423
 424         memset(cmd, 0, sizeof(*cmd));
 425         cmd->sc = sc;
 426         cmd->req.cmd = (struct virtio_scsi_cmd_req){
 427                 .lun[0] = 1,
 428                 .lun[1] = sc->device->id,
 429                 .lun[2] = (sc->device->lun >> 8) | 0x40,
 430                 .lun[3] = sc->device->lun & 0xff,
 431                 .tag = (unsigned long)sc,
 432                 .task_attr = VIRTIO_SCSI_S_SIMPLE,
 433                 .prio = 0,
 434                 .crn = 0,
 435         };
 436
 437         BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
 438         memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
 439
 440         if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
 441                               sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
 442                               GFP_ATOMIC) >= 0)
 443                 ret = 0;
 444
 445 out:
 446         return ret;
 447 }
 448
 449 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
 450 {
 451         DECLARE_COMPLETION_ONSTACK(comp);
 452         struct virtio_scsi_target_state *tgt = vscsi->tgt[cmd->sc->device->id];
 453         int ret = FAILED;
 454
 455         cmd->comp = &comp;
 456         if (virtscsi_kick_cmd(tgt, &vscsi->ctrl_vq, cmd,
 457                               sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
 458                               GFP_NOIO) < 0)
 459                 goto out;
 460
 461         wait_for_completion(&comp);
 462         if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
 463             cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
 464                 ret = SUCCESS;
 465
 466 out:
 467         mempool_free(cmd, virtscsi_cmd_pool);
 468         return ret;
 469 }
 470
 471 static int virtscsi_device_reset(struct scsi_cmnd *sc)
 472 {
 473         struct virtio_scsi *vscsi = shost_priv(sc->device->host);
 474         struct virtio_scsi_cmd *cmd;
 475
 476         sdev_printk(KERN_INFO, sc->device, "device reset\n");
 477         cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
 478         if (!cmd)
 479                 return FAILED;
 480
 481         memset(cmd, 0, sizeof(*cmd));
 482         cmd->sc = sc;
 483         cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
 484                 .type = VIRTIO_SCSI_T_TMF,
 485                 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
 486                 .lun[0] = 1,
 487                 .lun[1] = sc->device->id,
 488                 .lun[2] = (sc->device->lun >> 8) | 0x40,
 489                 .lun[3] = sc->device->lun & 0xff,
 490         };
 491         return virtscsi_tmf(vscsi, cmd);
 492 }
 493
 494 static int virtscsi_abort(struct scsi_cmnd *sc)
 495 {
 496         struct virtio_scsi *vscsi = shost_priv(sc->device->host);
 497         struct virtio_scsi_cmd *cmd;
 498
 499         scmd_printk(KERN_INFO, sc, "abort\n");
 500         cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
 501         if (!cmd)
 502                 return FAILED;
 503
 504         memset(cmd, 0, sizeof(*cmd));
 505         cmd->sc = sc;
 506         cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
 507                 .type = VIRTIO_SCSI_T_TMF,
 508                 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
 509                 .lun[0] = 1,
 510                 .lun[1] = sc->device->id,
 511                 .lun[2] = (sc->device->lun >> 8) | 0x40,
 512                 .lun[3] = sc->device->lun & 0xff,
 513                 .tag = (unsigned long)sc,
 514         };
 515         return virtscsi_tmf(vscsi, cmd);
 516 }
 517
 518 static struct scsi_host_template virtscsi_host_template = {
 519         .module = THIS_MODULE,
 520         .name = "Virtio SCSI HBA",
 521         .proc_name = "virtio_scsi",
 522         .queuecommand = virtscsi_queuecommand,
 523         .this_id = -1,
 524         .eh_abort_handler = virtscsi_abort,
 525         .eh_device_reset_handler = virtscsi_device_reset,
 526
 527         .can_queue = 1024,
 528         .dma_boundary = UINT_MAX,
 529         .use_clustering = ENABLE_CLUSTERING,
 530 };
 531
 532 #define virtscsi_config_get(vdev, fld) \
 533         ({ \
 534                 typeof(((struct virtio_scsi_config *)0)->fld) __val; \
 535                 vdev->config->get(vdev, \
 536                                   offsetof(struct virtio_scsi_config, fld), \
 537                                   &__val, sizeof(__val)); \
 538                 __val; \
 539         })
 540
 541 #define virtscsi_config_set(vdev, fld, val) \
 542         (void)({ \
 543                 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
 544                 vdev->config->set(vdev, \
 545                                   offsetof(struct virtio_scsi_config, fld), \
 546                                   &__val, sizeof(__val)); \
 547         })
 548
 549 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
 550                              struct virtqueue *vq)
 551 {
 552         spin_lock_init(&virtscsi_vq->vq_lock);
 553         virtscsi_vq->vq = vq;
 554 }
 555
 556 static struct virtio_scsi_target_state *virtscsi_alloc_tgt(
 557         struct virtio_device *vdev, int sg_elems)
 558 {
 559         struct virtio_scsi_target_state *tgt;
 560         gfp_t gfp_mask = GFP_KERNEL;
 561
 562         /* We need extra sg elements at head and tail.  */
 563         tgt = kmalloc(sizeof(*tgt) + sizeof(tgt->sg[0]) * (sg_elems + 2),
 564                       gfp_mask);
 565
 566         if (!tgt)
 567                 return NULL;
 568
 569         spin_lock_init(&tgt->tgt_lock);
 570         sg_init_table(tgt->sg, sg_elems + 2);
 571         return tgt;
 572 }
 573
 574 static void virtscsi_scan(struct virtio_device *vdev)
 575 {
 576         struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv;
 577
 578         scsi_scan_host(shost);
 579 }
 580
 581 static void virtscsi_remove_vqs(struct virtio_device *vdev)
 582 {
 583         struct Scsi_Host *sh = virtio_scsi_host(vdev);
 584         struct virtio_scsi *vscsi = shost_priv(sh);
 585         u32 i, num_targets;
 586
 587         /* Stop all the virtqueues. */
 588         vdev->config->reset(vdev);
 589
 590         num_targets = sh->max_id;
 591         for (i = 0; i < num_targets; i++) {
 592                 kfree(vscsi->tgt[i]);
 593                 vscsi->tgt[i] = NULL;
 594         }
 595
 596         vdev->config->del_vqs(vdev);
 597 }
 598
 599 static int virtscsi_init(struct virtio_device *vdev,
 600                          struct virtio_scsi *vscsi, int num_targets)
 601 {
 602         int err;
 603         struct virtqueue *vqs[3];
 604         u32 i, sg_elems;
 605
 606         vq_callback_t *callbacks[] = {
 607                 virtscsi_ctrl_done,
 608                 virtscsi_event_done,
 609                 virtscsi_req_done
 610         };
 611         const char *names[] = {
 612                 "control",
 613                 "event",
 614                 "request"
 615         };
 616
 617         /* Discover virtqueues and write information to configuration.  */
 618         err = vdev->config->find_vqs(vdev, 3, vqs, callbacks, names);
 619         if (err)
 620                 return err;
 621
 622         virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
 623         virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
 624         virtscsi_init_vq(&vscsi->req_vq, vqs[2]);
 625
 626         virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
 627         virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
 628
 629         if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
 630                 virtscsi_kick_event_all(vscsi);
 631
 632         /* We need to know how many segments before we allocate.  */
 633         sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
 634
 635         for (i = 0; i < num_targets; i++) {
 636                 vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
 637                 if (!vscsi->tgt[i]) {
 638                         err = -ENOMEM;
 639                         goto out;
 640                 }
 641         }
 642         err = 0;
 643
 644 out:
 645         if (err)
 646                 virtscsi_remove_vqs(vdev);
 647         return err;
 648 }
 649
 650 static int __devinit virtscsi_probe(struct virtio_device *vdev)
 651 {
 652         struct Scsi_Host *shost;
 653         struct virtio_scsi *vscsi;
 654         int err;
 655         u32 sg_elems, num_targets;
 656         u32 cmd_per_lun;
 657
 658         /* Allocate memory and link the structs together.  */
 659         num_targets = virtscsi_config_get(vdev, max_target) + 1;
 660         shost = scsi_host_alloc(&virtscsi_host_template,
 661                 sizeof(*vscsi)
 662                 + num_targets * sizeof(struct virtio_scsi_target_state));
 663
 664         if (!shost)
 665                 return -ENOMEM;
 666
 667         sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
 668         shost->sg_tablesize = sg_elems;
 669         vscsi = shost_priv(shost);
 670         vscsi->vdev = vdev;
 671         vdev->priv = shost;
 672
 673         err = virtscsi_init(vdev, vscsi, num_targets);
 674         if (err)
 675                 goto virtscsi_init_failed;
 676
 677         cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
 678         shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
 679         shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
 680         shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1;
 681         shost->max_id = num_targets;
 682         shost->max_channel = 0;
 683         shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
 684         err = scsi_add_host(shost, &vdev->dev);
 685         if (err)
 686                 goto scsi_add_host_failed;
 687         /*
 688          * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
 689          * after VIRTIO_CONFIG_S_DRIVER_OK has been set..
 690          */
 691         return 0;
 692
 693 scsi_add_host_failed:
 694         vdev->config->del_vqs(vdev);
 695 virtscsi_init_failed:
 696         scsi_host_put(shost);
 697         return err;
 698 }
 699
 700 static void __devexit virtscsi_remove(struct virtio_device *vdev)
 701 {
 702         struct Scsi_Host *shost = virtio_scsi_host(vdev);
 703         struct virtio_scsi *vscsi = shost_priv(shost);
 704
 705         if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
 706                 virtscsi_cancel_event_work(vscsi);
 707
 708         scsi_remove_host(shost);
 709
 710         virtscsi_remove_vqs(vdev);
 711         scsi_host_put(shost);
 712 }
 713
 714 #ifdef CONFIG_PM
 715 static int virtscsi_freeze(struct virtio_device *vdev)
 716 {
 717         virtscsi_remove_vqs(vdev);
 718         return 0;
 719 }
 720
 721 static int virtscsi_restore(struct virtio_device *vdev)
 722 {
 723         struct Scsi_Host *sh = virtio_scsi_host(vdev);
 724         struct virtio_scsi *vscsi = shost_priv(sh);
 725
 726         return virtscsi_init(vdev, vscsi, sh->max_id);
 727 }
 728 #endif
 729
 730 static struct virtio_device_id id_table[] = {
 731         { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
 732         { 0 },
 733 };
 734
 735 static unsigned int features[] = {
 736         VIRTIO_SCSI_F_HOTPLUG
 737 };
 738
 739 static struct virtio_driver virtio_scsi_driver = {
 740         .feature_table = features,
 741         .feature_table_size = ARRAY_SIZE(features),
 742         .driver.name = KBUILD_MODNAME,
 743         .driver.owner = THIS_MODULE,
 744         .id_table = id_table,
 745         .probe = virtscsi_probe,
 746         .scan = virtscsi_scan,
 747 #ifdef CONFIG_PM
 748         .freeze = virtscsi_freeze,
 749         .restore = virtscsi_restore,
 750 #endif
 751         .remove = __devexit_p(virtscsi_remove),
 752 };
 753
 754 static int __init init(void)
 755 {
 756         int ret = -ENOMEM;
 757
 758         virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
 759         if (!virtscsi_cmd_cache) {
 760                 printk(KERN_ERR "kmem_cache_create() for "
 761                                 "virtscsi_cmd_cache failed\n");
 762                 goto error;
 763         }
 764
 765
 766         virtscsi_cmd_pool =
 767                 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
 768                                          virtscsi_cmd_cache);
 769         if (!virtscsi_cmd_pool) {
 770                 printk(KERN_ERR "mempool_create() for"
 771                                 "virtscsi_cmd_pool failed\n");
 772                 goto error;
 773         }
 774         ret = register_virtio_driver(&virtio_scsi_driver);
 775         if (ret < 0)
 776                 goto error;
 777
 778         return 0;
 779
 780 error:
 781         if (virtscsi_cmd_pool) {
 782                 mempool_destroy(virtscsi_cmd_pool);
 783                 virtscsi_cmd_pool = NULL;
 784         }
 785         if (virtscsi_cmd_cache) {
 786                 kmem_cache_destroy(virtscsi_cmd_cache);
 787                 virtscsi_cmd_cache = NULL;
 788         }
 789         return ret;
 790 }
 791
 792 static void __exit fini(void)
 793 {
 794         unregister_virtio_driver(&virtio_scsi_driver);
 795         mempool_destroy(virtscsi_cmd_pool);
 796         kmem_cache_destroy(virtscsi_cmd_cache);
 797 }
 798 module_init(init);
 799 module_exit(fini);
 800
 801 MODULE_DEVICE_TABLE(virtio, id_table);
 802 MODULE_DESCRIPTION("Virtio SCSI HBA driver");
 803 MODULE_LICENSE("GPL");