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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/module.h> 19 #include <linux/slab.h> 20 #include <linux/mempool.h> 21 #include <linux/virtio.h> 22 #include <linux/virtio_ids.h> 23 #include <linux/virtio_config.h> 24 #include <linux/virtio_scsi.h> 25 #include <linux/cpu.h> 26 #include <linux/blkdev.h> 27 #include <scsi/scsi_host.h> 28 #include <scsi/scsi_device.h> 29 #include <scsi/scsi_cmnd.h> 30 #include <scsi/scsi_tcq.h> 31 #include <linux/seqlock.h> 32 33 #define VIRTIO_SCSI_MEMPOOL_SZ 64 34 #define VIRTIO_SCSI_EVENT_LEN 8 35 #define VIRTIO_SCSI_VQ_BASE 2 36 37 /* Command queue element */ 38 struct virtio_scsi_cmd { 39 struct scsi_cmnd *sc; 40 struct completion *comp; 41 union { 42 struct virtio_scsi_cmd_req cmd; 43 struct virtio_scsi_cmd_req_pi cmd_pi; 44 struct virtio_scsi_ctrl_tmf_req tmf; 45 struct virtio_scsi_ctrl_an_req an; 46 } req; 47 union { 48 struct virtio_scsi_cmd_resp cmd; 49 struct virtio_scsi_ctrl_tmf_resp tmf; 50 struct virtio_scsi_ctrl_an_resp an; 51 struct virtio_scsi_event evt; 52 } resp; 53 } ____cacheline_aligned_in_smp; 54 55 struct virtio_scsi_event_node { 56 struct virtio_scsi *vscsi; 57 struct virtio_scsi_event event; 58 struct work_struct work; 59 }; 60 61 struct virtio_scsi_vq { 62 /* Protects vq */ 63 spinlock_t vq_lock; 64 65 struct virtqueue *vq; 66 }; 67 68 /* 69 * Per-target queue state. 70 * 71 * This struct holds the data needed by the queue steering policy. When a 72 * target is sent multiple requests, we need to drive them to the same queue so 73 * that FIFO processing order is kept. However, if a target was idle, we can 74 * choose a queue arbitrarily. In this case the queue is chosen according to 75 * the current VCPU, so the driver expects the number of request queues to be 76 * equal to the number of VCPUs. This makes it easy and fast to select the 77 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues 78 * (each virtqueue's affinity is set to the CPU that "owns" the queue). 79 * 80 * tgt_seq is held to serialize reading and writing req_vq. 81 * 82 * Decrements of reqs are never concurrent with writes of req_vq: before the 83 * decrement reqs will be != 0; after the decrement the virtqueue completion 84 * routine will not use the req_vq so it can be changed by a new request. 85 * Thus they can happen outside the tgt_seq, provided of course we make reqs 86 * an atomic_t. 87 */ 88 struct virtio_scsi_target_state { 89 seqcount_t tgt_seq; 90 91 /* Count of outstanding requests. */ 92 atomic_t reqs; 93 94 /* Currently active virtqueue for requests sent to this target. */ 95 struct virtio_scsi_vq *req_vq; 96 }; 97 98 /* Driver instance state */ 99 struct virtio_scsi { 100 struct virtio_device *vdev; 101 102 /* Get some buffers ready for event vq */ 103 struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; 104 105 u32 num_queues; 106 107 /* If the affinity hint is set for virtqueues */ 108 bool affinity_hint_set; 109 110 /* CPU hotplug notifier */ 111 struct notifier_block nb; 112 113 /* Protected by event_vq lock */ 114 bool stop_events; 115 116 struct virtio_scsi_vq ctrl_vq; 117 struct virtio_scsi_vq event_vq; 118 struct virtio_scsi_vq req_vqs[]; 119 }; 120 121 static struct kmem_cache *virtscsi_cmd_cache; 122 static mempool_t *virtscsi_cmd_pool; 123 124 static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) 125 { 126 return vdev->priv; 127 } 128 129 static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) 130 { 131 if (!resid) 132 return; 133 134 if (!scsi_bidi_cmnd(sc)) { 135 scsi_set_resid(sc, resid); 136 return; 137 } 138 139 scsi_in(sc)->resid = min(resid, scsi_in(sc)->length); 140 scsi_out(sc)->resid = resid - scsi_in(sc)->resid; 141 } 142 143 /** 144 * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done 145 * 146 * Called with vq_lock held. 147 */ 148 static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) 149 { 150 struct virtio_scsi_cmd *cmd = buf; 151 struct scsi_cmnd *sc = cmd->sc; 152 struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; 153 struct virtio_scsi_target_state *tgt = 154 scsi_target(sc->device)->hostdata; 155 156 dev_dbg(&sc->device->sdev_gendev, 157 "cmd %p response %u status %#02x sense_len %u\n", 158 sc, resp->response, resp->status, resp->sense_len); 159 160 sc->result = resp->status; 161 virtscsi_compute_resid(sc, resp->resid); 162 switch (resp->response) { 163 case VIRTIO_SCSI_S_OK: 164 set_host_byte(sc, DID_OK); 165 break; 166 case VIRTIO_SCSI_S_OVERRUN: 167 set_host_byte(sc, DID_ERROR); 168 break; 169 case VIRTIO_SCSI_S_ABORTED: 170 set_host_byte(sc, DID_ABORT); 171 break; 172 case VIRTIO_SCSI_S_BAD_TARGET: 173 set_host_byte(sc, DID_BAD_TARGET); 174 break; 175 case VIRTIO_SCSI_S_RESET: 176 set_host_byte(sc, DID_RESET); 177 break; 178 case VIRTIO_SCSI_S_BUSY: 179 set_host_byte(sc, DID_BUS_BUSY); 180 break; 181 case VIRTIO_SCSI_S_TRANSPORT_FAILURE: 182 set_host_byte(sc, DID_TRANSPORT_DISRUPTED); 183 break; 184 case VIRTIO_SCSI_S_TARGET_FAILURE: 185 set_host_byte(sc, DID_TARGET_FAILURE); 186 break; 187 case VIRTIO_SCSI_S_NEXUS_FAILURE: 188 set_host_byte(sc, DID_NEXUS_FAILURE); 189 break; 190 default: 191 scmd_printk(KERN_WARNING, sc, "Unknown response %d", 192 resp->response); 193 /* fall through */ 194 case VIRTIO_SCSI_S_FAILURE: 195 set_host_byte(sc, DID_ERROR); 196 break; 197 } 198 199 WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE); 200 if (sc->sense_buffer) { 201 memcpy(sc->sense_buffer, resp->sense, 202 min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE)); 203 if (resp->sense_len) 204 set_driver_byte(sc, DRIVER_SENSE); 205 } 206 207 sc->scsi_done(sc); 208 209 atomic_dec(&tgt->reqs); 210 } 211 212 static void virtscsi_vq_done(struct virtio_scsi *vscsi, 213 struct virtio_scsi_vq *virtscsi_vq, 214 void (*fn)(struct virtio_scsi *vscsi, void *buf)) 215 { 216 void *buf; 217 unsigned int len; 218 unsigned long flags; 219 struct virtqueue *vq = virtscsi_vq->vq; 220 221 spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); 222 do { 223 virtqueue_disable_cb(vq); 224 while ((buf = virtqueue_get_buf(vq, &len)) != NULL) 225 fn(vscsi, buf); 226 227 if (unlikely(virtqueue_is_broken(vq))) 228 break; 229 } while (!virtqueue_enable_cb(vq)); 230 spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); 231 } 232 233 static void virtscsi_req_done(struct virtqueue *vq) 234 { 235 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 236 struct virtio_scsi *vscsi = shost_priv(sh); 237 int index = vq->index - VIRTIO_SCSI_VQ_BASE; 238 struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; 239 240 virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); 241 }; 242 243 static void virtscsi_poll_requests(struct virtio_scsi *vscsi) 244 { 245 int i, num_vqs; 246 247 num_vqs = vscsi->num_queues; 248 for (i = 0; i < num_vqs; i++) 249 virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], 250 virtscsi_complete_cmd); 251 } 252 253 static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) 254 { 255 struct virtio_scsi_cmd *cmd = buf; 256 257 if (cmd->comp) 258 complete_all(cmd->comp); 259 } 260 261 static void virtscsi_ctrl_done(struct virtqueue *vq) 262 { 263 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 264 struct virtio_scsi *vscsi = shost_priv(sh); 265 266 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 267 }; 268 269 static void virtscsi_handle_event(struct work_struct *work); 270 271 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 272 struct virtio_scsi_event_node *event_node) 273 { 274 int err; 275 struct scatterlist sg; 276 unsigned long flags; 277 278 INIT_WORK(&event_node->work, virtscsi_handle_event); 279 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 280 281 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 282 283 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 284 GFP_ATOMIC); 285 if (!err) 286 virtqueue_kick(vscsi->event_vq.vq); 287 288 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 289 290 return err; 291 } 292 293 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 294 { 295 int i; 296 297 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 298 vscsi->event_list[i].vscsi = vscsi; 299 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 300 } 301 302 return 0; 303 } 304 305 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 306 { 307 int i; 308 309 /* Stop scheduling work before calling cancel_work_sync. */ 310 spin_lock_irq(&vscsi->event_vq.vq_lock); 311 vscsi->stop_events = true; 312 spin_unlock_irq(&vscsi->event_vq.vq_lock); 313 314 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 315 cancel_work_sync(&vscsi->event_list[i].work); 316 } 317 318 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 319 struct virtio_scsi_event *event) 320 { 321 struct scsi_device *sdev; 322 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 323 unsigned int target = event->lun[1]; 324 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 325 326 switch (event->reason) { 327 case VIRTIO_SCSI_EVT_RESET_RESCAN: 328 scsi_add_device(shost, 0, target, lun); 329 break; 330 case VIRTIO_SCSI_EVT_RESET_REMOVED: 331 sdev = scsi_device_lookup(shost, 0, target, lun); 332 if (sdev) { 333 scsi_remove_device(sdev); 334 scsi_device_put(sdev); 335 } else { 336 pr_err("SCSI device %d 0 %d %d not found\n", 337 shost->host_no, target, lun); 338 } 339 break; 340 default: 341 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 342 } 343 } 344 345 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 346 struct virtio_scsi_event *event) 347 { 348 struct scsi_device *sdev; 349 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 350 unsigned int target = event->lun[1]; 351 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 352 u8 asc = event->reason & 255; 353 u8 ascq = event->reason >> 8; 354 355 sdev = scsi_device_lookup(shost, 0, target, lun); 356 if (!sdev) { 357 pr_err("SCSI device %d 0 %d %d not found\n", 358 shost->host_no, target, lun); 359 return; 360 } 361 362 /* Handle "Parameters changed", "Mode parameters changed", and 363 "Capacity data has changed". */ 364 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 365 scsi_rescan_device(&sdev->sdev_gendev); 366 367 scsi_device_put(sdev); 368 } 369 370 static void virtscsi_handle_event(struct work_struct *work) 371 { 372 struct virtio_scsi_event_node *event_node = 373 container_of(work, struct virtio_scsi_event_node, work); 374 struct virtio_scsi *vscsi = event_node->vscsi; 375 struct virtio_scsi_event *event = &event_node->event; 376 377 if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) { 378 event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED; 379 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 380 } 381 382 switch (event->event) { 383 case VIRTIO_SCSI_T_NO_EVENT: 384 break; 385 case VIRTIO_SCSI_T_TRANSPORT_RESET: 386 virtscsi_handle_transport_reset(vscsi, event); 387 break; 388 case VIRTIO_SCSI_T_PARAM_CHANGE: 389 virtscsi_handle_param_change(vscsi, event); 390 break; 391 default: 392 pr_err("Unsupport virtio scsi event %x\n", event->event); 393 } 394 virtscsi_kick_event(vscsi, event_node); 395 } 396 397 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 398 { 399 struct virtio_scsi_event_node *event_node = buf; 400 401 if (!vscsi->stop_events) 402 queue_work(system_freezable_wq, &event_node->work); 403 } 404 405 static void virtscsi_event_done(struct virtqueue *vq) 406 { 407 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 408 struct virtio_scsi *vscsi = shost_priv(sh); 409 410 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 411 }; 412 413 /** 414 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue 415 * @vq : the struct virtqueue we're talking about 416 * @cmd : command structure 417 * @req_size : size of the request buffer 418 * @resp_size : size of the response buffer 419 */ 420 static int virtscsi_add_cmd(struct virtqueue *vq, 421 struct virtio_scsi_cmd *cmd, 422 size_t req_size, size_t resp_size) 423 { 424 struct scsi_cmnd *sc = cmd->sc; 425 struct scatterlist *sgs[6], req, resp; 426 struct sg_table *out, *in; 427 unsigned out_num = 0, in_num = 0; 428 429 out = in = NULL; 430 431 if (sc && sc->sc_data_direction != DMA_NONE) { 432 if (sc->sc_data_direction != DMA_FROM_DEVICE) 433 out = &scsi_out(sc)->table; 434 if (sc->sc_data_direction != DMA_TO_DEVICE) 435 in = &scsi_in(sc)->table; 436 } 437 438 /* Request header. */ 439 sg_init_one(&req, &cmd->req, req_size); 440 sgs[out_num++] = &req; 441 442 /* Data-out buffer. */ 443 if (out) { 444 /* Place WRITE protection SGLs before Data OUT payload */ 445 if (scsi_prot_sg_count(sc)) 446 sgs[out_num++] = scsi_prot_sglist(sc); 447 sgs[out_num++] = out->sgl; 448 } 449 450 /* Response header. */ 451 sg_init_one(&resp, &cmd->resp, resp_size); 452 sgs[out_num + in_num++] = &resp; 453 454 /* Data-in buffer */ 455 if (in) { 456 /* Place READ protection SGLs before Data IN payload */ 457 if (scsi_prot_sg_count(sc)) 458 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 459 sgs[out_num + in_num++] = in->sgl; 460 } 461 462 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 463 } 464 465 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, 466 struct virtio_scsi_cmd *cmd, 467 size_t req_size, size_t resp_size) 468 { 469 unsigned long flags; 470 int err; 471 bool needs_kick = false; 472 473 spin_lock_irqsave(&vq->vq_lock, flags); 474 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 475 if (!err) 476 needs_kick = virtqueue_kick_prepare(vq->vq); 477 478 spin_unlock_irqrestore(&vq->vq_lock, flags); 479 480 if (needs_kick) 481 virtqueue_notify(vq->vq); 482 return err; 483 } 484 485 static void virtio_scsi_init_hdr(struct virtio_scsi_cmd_req *cmd, 486 struct scsi_cmnd *sc) 487 { 488 cmd->lun[0] = 1; 489 cmd->lun[1] = sc->device->id; 490 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 491 cmd->lun[3] = sc->device->lun & 0xff; 492 cmd->tag = (unsigned long)sc; 493 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 494 cmd->prio = 0; 495 cmd->crn = 0; 496 } 497 498 static void virtio_scsi_init_hdr_pi(struct virtio_scsi_cmd_req_pi *cmd_pi, 499 struct scsi_cmnd *sc) 500 { 501 struct request *rq = sc->request; 502 struct blk_integrity *bi; 503 504 virtio_scsi_init_hdr((struct virtio_scsi_cmd_req *)cmd_pi, sc); 505 506 if (!rq || !scsi_prot_sg_count(sc)) 507 return; 508 509 bi = blk_get_integrity(rq->rq_disk); 510 511 if (sc->sc_data_direction == DMA_TO_DEVICE) 512 cmd_pi->pi_bytesout = blk_rq_sectors(rq) * bi->tuple_size; 513 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 514 cmd_pi->pi_bytesin = blk_rq_sectors(rq) * bi->tuple_size; 515 } 516 517 static int virtscsi_queuecommand(struct virtio_scsi *vscsi, 518 struct virtio_scsi_vq *req_vq, 519 struct scsi_cmnd *sc) 520 { 521 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 522 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 523 int req_size; 524 525 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 526 527 /* TODO: check feature bit and fail if unsupported? */ 528 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 529 530 dev_dbg(&sc->device->sdev_gendev, 531 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 532 533 memset(cmd, 0, sizeof(*cmd)); 534 cmd->sc = sc; 535 536 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 537 538 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 539 virtio_scsi_init_hdr_pi(&cmd->req.cmd_pi, sc); 540 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 541 req_size = sizeof(cmd->req.cmd_pi); 542 } else { 543 virtio_scsi_init_hdr(&cmd->req.cmd, sc); 544 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 545 req_size = sizeof(cmd->req.cmd); 546 } 547 548 if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0) 549 return SCSI_MLQUEUE_HOST_BUSY; 550 return 0; 551 } 552 553 static int virtscsi_queuecommand_single(struct Scsi_Host *sh, 554 struct scsi_cmnd *sc) 555 { 556 struct virtio_scsi *vscsi = shost_priv(sh); 557 struct virtio_scsi_target_state *tgt = 558 scsi_target(sc->device)->hostdata; 559 560 atomic_inc(&tgt->reqs); 561 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); 562 } 563 564 static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, 565 struct virtio_scsi_target_state *tgt) 566 { 567 struct virtio_scsi_vq *vq; 568 unsigned long flags; 569 u32 queue_num; 570 571 local_irq_save(flags); 572 if (atomic_inc_return(&tgt->reqs) > 1) { 573 unsigned long seq; 574 575 do { 576 seq = read_seqcount_begin(&tgt->tgt_seq); 577 vq = tgt->req_vq; 578 } while (read_seqcount_retry(&tgt->tgt_seq, seq)); 579 } else { 580 /* no writes can be concurrent because of atomic_t */ 581 write_seqcount_begin(&tgt->tgt_seq); 582 583 /* keep previous req_vq if a reader just arrived */ 584 if (unlikely(atomic_read(&tgt->reqs) > 1)) { 585 vq = tgt->req_vq; 586 goto unlock; 587 } 588 589 queue_num = smp_processor_id(); 590 while (unlikely(queue_num >= vscsi->num_queues)) 591 queue_num -= vscsi->num_queues; 592 tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; 593 unlock: 594 write_seqcount_end(&tgt->tgt_seq); 595 } 596 local_irq_restore(flags); 597 598 return vq; 599 } 600 601 static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, 602 struct scsi_cmnd *sc) 603 { 604 struct virtio_scsi *vscsi = shost_priv(sh); 605 struct virtio_scsi_target_state *tgt = 606 scsi_target(sc->device)->hostdata; 607 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt); 608 609 return virtscsi_queuecommand(vscsi, req_vq, sc); 610 } 611 612 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 613 { 614 DECLARE_COMPLETION_ONSTACK(comp); 615 int ret = FAILED; 616 617 cmd->comp = ∁ 618 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, 619 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0) 620 goto out; 621 622 wait_for_completion(&comp); 623 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 624 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 625 ret = SUCCESS; 626 627 /* 628 * The spec guarantees that all requests related to the TMF have 629 * been completed, but the callback might not have run yet if 630 * we're using independent interrupts (e.g. MSI). Poll the 631 * virtqueues once. 632 * 633 * In the abort case, sc->scsi_done will do nothing, because 634 * the block layer must have detected a timeout and as a result 635 * REQ_ATOM_COMPLETE has been set. 636 */ 637 virtscsi_poll_requests(vscsi); 638 639 out: 640 mempool_free(cmd, virtscsi_cmd_pool); 641 return ret; 642 } 643 644 static int virtscsi_device_reset(struct scsi_cmnd *sc) 645 { 646 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 647 struct virtio_scsi_cmd *cmd; 648 649 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 650 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 651 if (!cmd) 652 return FAILED; 653 654 memset(cmd, 0, sizeof(*cmd)); 655 cmd->sc = sc; 656 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 657 .type = VIRTIO_SCSI_T_TMF, 658 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET, 659 .lun[0] = 1, 660 .lun[1] = sc->device->id, 661 .lun[2] = (sc->device->lun >> 8) | 0x40, 662 .lun[3] = sc->device->lun & 0xff, 663 }; 664 return virtscsi_tmf(vscsi, cmd); 665 } 666 667 /** 668 * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth 669 * @sdev: Virtscsi target whose queue depth to change 670 * @qdepth: New queue depth 671 * @reason: Reason for the queue depth change. 672 */ 673 static int virtscsi_change_queue_depth(struct scsi_device *sdev, 674 int qdepth, 675 int reason) 676 { 677 struct Scsi_Host *shost = sdev->host; 678 int max_depth = shost->cmd_per_lun; 679 680 switch (reason) { 681 case SCSI_QDEPTH_QFULL: /* Drop qdepth in response to BUSY state */ 682 scsi_track_queue_full(sdev, qdepth); 683 break; 684 case SCSI_QDEPTH_RAMP_UP: /* Raise qdepth after BUSY state resolved */ 685 case SCSI_QDEPTH_DEFAULT: /* Manual change via sysfs */ 686 scsi_adjust_queue_depth(sdev, 687 scsi_get_tag_type(sdev), 688 min(max_depth, qdepth)); 689 break; 690 default: 691 return -EOPNOTSUPP; 692 } 693 694 return sdev->queue_depth; 695 } 696 697 static int virtscsi_abort(struct scsi_cmnd *sc) 698 { 699 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 700 struct virtio_scsi_cmd *cmd; 701 702 scmd_printk(KERN_INFO, sc, "abort\n"); 703 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 704 if (!cmd) 705 return FAILED; 706 707 memset(cmd, 0, sizeof(*cmd)); 708 cmd->sc = sc; 709 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 710 .type = VIRTIO_SCSI_T_TMF, 711 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 712 .lun[0] = 1, 713 .lun[1] = sc->device->id, 714 .lun[2] = (sc->device->lun >> 8) | 0x40, 715 .lun[3] = sc->device->lun & 0xff, 716 .tag = (unsigned long)sc, 717 }; 718 return virtscsi_tmf(vscsi, cmd); 719 } 720 721 static int virtscsi_target_alloc(struct scsi_target *starget) 722 { 723 struct Scsi_Host *sh = dev_to_shost(starget->dev.parent); 724 struct virtio_scsi *vscsi = shost_priv(sh); 725 726 struct virtio_scsi_target_state *tgt = 727 kmalloc(sizeof(*tgt), GFP_KERNEL); 728 if (!tgt) 729 return -ENOMEM; 730 731 seqcount_init(&tgt->tgt_seq); 732 atomic_set(&tgt->reqs, 0); 733 tgt->req_vq = &vscsi->req_vqs[0]; 734 735 starget->hostdata = tgt; 736 return 0; 737 } 738 739 static void virtscsi_target_destroy(struct scsi_target *starget) 740 { 741 struct virtio_scsi_target_state *tgt = starget->hostdata; 742 kfree(tgt); 743 } 744 745 static struct scsi_host_template virtscsi_host_template_single = { 746 .module = THIS_MODULE, 747 .name = "Virtio SCSI HBA", 748 .proc_name = "virtio_scsi", 749 .this_id = -1, 750 .cmd_size = sizeof(struct virtio_scsi_cmd), 751 .queuecommand = virtscsi_queuecommand_single, 752 .change_queue_depth = virtscsi_change_queue_depth, 753 .eh_abort_handler = virtscsi_abort, 754 .eh_device_reset_handler = virtscsi_device_reset, 755 756 .can_queue = 1024, 757 .dma_boundary = UINT_MAX, 758 .use_clustering = ENABLE_CLUSTERING, 759 .target_alloc = virtscsi_target_alloc, 760 .target_destroy = virtscsi_target_destroy, 761 }; 762 763 static struct scsi_host_template virtscsi_host_template_multi = { 764 .module = THIS_MODULE, 765 .name = "Virtio SCSI HBA", 766 .proc_name = "virtio_scsi", 767 .this_id = -1, 768 .cmd_size = sizeof(struct virtio_scsi_cmd), 769 .queuecommand = virtscsi_queuecommand_multi, 770 .change_queue_depth = virtscsi_change_queue_depth, 771 .eh_abort_handler = virtscsi_abort, 772 .eh_device_reset_handler = virtscsi_device_reset, 773 774 .can_queue = 1024, 775 .dma_boundary = UINT_MAX, 776 .use_clustering = ENABLE_CLUSTERING, 777 .target_alloc = virtscsi_target_alloc, 778 .target_destroy = virtscsi_target_destroy, 779 }; 780 781 #define virtscsi_config_get(vdev, fld) \ 782 ({ \ 783 typeof(((struct virtio_scsi_config *)0)->fld) __val; \ 784 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 785 __val; \ 786 }) 787 788 #define virtscsi_config_set(vdev, fld, val) \ 789 do { \ 790 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ 791 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 792 } while(0) 793 794 static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 795 { 796 int i; 797 int cpu; 798 799 /* In multiqueue mode, when the number of cpu is equal 800 * to the number of request queues, we let the qeueues 801 * to be private to one cpu by setting the affinity hint 802 * to eliminate the contention. 803 */ 804 if ((vscsi->num_queues == 1 || 805 vscsi->num_queues != num_online_cpus()) && affinity) { 806 if (vscsi->affinity_hint_set) 807 affinity = false; 808 else 809 return; 810 } 811 812 if (affinity) { 813 i = 0; 814 for_each_online_cpu(cpu) { 815 virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu); 816 i++; 817 } 818 819 vscsi->affinity_hint_set = true; 820 } else { 821 for (i = 0; i < vscsi->num_queues; i++) { 822 if (!vscsi->req_vqs[i].vq) 823 continue; 824 825 virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); 826 } 827 828 vscsi->affinity_hint_set = false; 829 } 830 } 831 832 static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 833 { 834 get_online_cpus(); 835 __virtscsi_set_affinity(vscsi, affinity); 836 put_online_cpus(); 837 } 838 839 static int virtscsi_cpu_callback(struct notifier_block *nfb, 840 unsigned long action, void *hcpu) 841 { 842 struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb); 843 switch(action) { 844 case CPU_ONLINE: 845 case CPU_ONLINE_FROZEN: 846 case CPU_DEAD: 847 case CPU_DEAD_FROZEN: 848 __virtscsi_set_affinity(vscsi, true); 849 break; 850 default: 851 break; 852 } 853 return NOTIFY_OK; 854 } 855 856 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 857 struct virtqueue *vq) 858 { 859 spin_lock_init(&virtscsi_vq->vq_lock); 860 virtscsi_vq->vq = vq; 861 } 862 863 static void virtscsi_remove_vqs(struct virtio_device *vdev) 864 { 865 struct Scsi_Host *sh = virtio_scsi_host(vdev); 866 struct virtio_scsi *vscsi = shost_priv(sh); 867 868 virtscsi_set_affinity(vscsi, false); 869 870 /* Stop all the virtqueues. */ 871 vdev->config->reset(vdev); 872 873 vdev->config->del_vqs(vdev); 874 } 875 876 static int virtscsi_init(struct virtio_device *vdev, 877 struct virtio_scsi *vscsi) 878 { 879 int err; 880 u32 i; 881 u32 num_vqs; 882 vq_callback_t **callbacks; 883 const char **names; 884 struct virtqueue **vqs; 885 886 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 887 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); 888 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL); 889 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL); 890 891 if (!callbacks || !vqs || !names) { 892 err = -ENOMEM; 893 goto out; 894 } 895 896 callbacks[0] = virtscsi_ctrl_done; 897 callbacks[1] = virtscsi_event_done; 898 names[0] = "control"; 899 names[1] = "event"; 900 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 901 callbacks[i] = virtscsi_req_done; 902 names[i] = "request"; 903 } 904 905 /* Discover virtqueues and write information to configuration. */ 906 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); 907 if (err) 908 goto out; 909 910 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 911 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 912 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 913 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 914 vqs[i]); 915 916 virtscsi_set_affinity(vscsi, true); 917 918 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 919 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 920 921 err = 0; 922 923 out: 924 kfree(names); 925 kfree(callbacks); 926 kfree(vqs); 927 if (err) 928 virtscsi_remove_vqs(vdev); 929 return err; 930 } 931 932 static int virtscsi_probe(struct virtio_device *vdev) 933 { 934 struct Scsi_Host *shost; 935 struct virtio_scsi *vscsi; 936 int err, host_prot; 937 u32 sg_elems, num_targets; 938 u32 cmd_per_lun; 939 u32 num_queues; 940 struct scsi_host_template *hostt; 941 942 /* We need to know how many queues before we allocate. */ 943 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 944 945 num_targets = virtscsi_config_get(vdev, max_target) + 1; 946 947 if (num_queues == 1) 948 hostt = &virtscsi_host_template_single; 949 else 950 hostt = &virtscsi_host_template_multi; 951 952 shost = scsi_host_alloc(hostt, 953 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); 954 if (!shost) 955 return -ENOMEM; 956 957 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 958 shost->sg_tablesize = sg_elems; 959 vscsi = shost_priv(shost); 960 vscsi->vdev = vdev; 961 vscsi->num_queues = num_queues; 962 vdev->priv = shost; 963 964 err = virtscsi_init(vdev, vscsi); 965 if (err) 966 goto virtscsi_init_failed; 967 968 vscsi->nb.notifier_call = &virtscsi_cpu_callback; 969 err = register_hotcpu_notifier(&vscsi->nb); 970 if (err) { 971 pr_err("registering cpu notifier failed\n"); 972 goto scsi_add_host_failed; 973 } 974 975 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 976 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 977 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 978 979 /* LUNs > 256 are reported with format 1, so they go in the range 980 * 16640-32767. 981 */ 982 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 983 shost->max_id = num_targets; 984 shost->max_channel = 0; 985 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 986 987 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 988 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 989 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 990 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 991 992 scsi_host_set_prot(shost, host_prot); 993 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 994 } 995 996 err = scsi_add_host(shost, &vdev->dev); 997 if (err) 998 goto scsi_add_host_failed; 999 1000 virtio_device_ready(vdev); 1001 1002 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1003 virtscsi_kick_event_all(vscsi); 1004 1005 scsi_scan_host(shost); 1006 return 0; 1007 1008 scsi_add_host_failed: 1009 vdev->config->del_vqs(vdev); 1010 virtscsi_init_failed: 1011 scsi_host_put(shost); 1012 return err; 1013 } 1014 1015 static void virtscsi_remove(struct virtio_device *vdev) 1016 { 1017 struct Scsi_Host *shost = virtio_scsi_host(vdev); 1018 struct virtio_scsi *vscsi = shost_priv(shost); 1019 1020 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1021 virtscsi_cancel_event_work(vscsi); 1022 1023 scsi_remove_host(shost); 1024 1025 unregister_hotcpu_notifier(&vscsi->nb); 1026 1027 virtscsi_remove_vqs(vdev); 1028 scsi_host_put(shost); 1029 } 1030 1031 #ifdef CONFIG_PM_SLEEP 1032 static int virtscsi_freeze(struct virtio_device *vdev) 1033 { 1034 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1035 struct virtio_scsi *vscsi = shost_priv(sh); 1036 1037 unregister_hotcpu_notifier(&vscsi->nb); 1038 virtscsi_remove_vqs(vdev); 1039 return 0; 1040 } 1041 1042 static int virtscsi_restore(struct virtio_device *vdev) 1043 { 1044 struct Scsi_Host *sh = virtio_scsi_host(vdev); 1045 struct virtio_scsi *vscsi = shost_priv(sh); 1046 int err; 1047 1048 err = virtscsi_init(vdev, vscsi); 1049 if (err) 1050 return err; 1051 1052 err = register_hotcpu_notifier(&vscsi->nb); 1053 if (err) { 1054 vdev->config->del_vqs(vdev); 1055 return err; 1056 } 1057 1058 virtio_device_ready(vdev); 1059 1060 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 1061 virtscsi_kick_event_all(vscsi); 1062 1063 return err; 1064 } 1065 #endif 1066 1067 static struct virtio_device_id id_table[] = { 1068 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 1069 { 0 }, 1070 }; 1071 1072 static unsigned int features[] = { 1073 VIRTIO_SCSI_F_HOTPLUG, 1074 VIRTIO_SCSI_F_CHANGE, 1075 VIRTIO_SCSI_F_T10_PI, 1076 }; 1077 1078 static struct virtio_driver virtio_scsi_driver = { 1079 .feature_table = features, 1080 .feature_table_size = ARRAY_SIZE(features), 1081 .driver.name = KBUILD_MODNAME, 1082 .driver.owner = THIS_MODULE, 1083 .id_table = id_table, 1084 .probe = virtscsi_probe, 1085 #ifdef CONFIG_PM_SLEEP 1086 .freeze = virtscsi_freeze, 1087 .restore = virtscsi_restore, 1088 #endif 1089 .remove = virtscsi_remove, 1090 }; 1091 1092 static int __init init(void) 1093 { 1094 int ret = -ENOMEM; 1095 1096 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1097 if (!virtscsi_cmd_cache) { 1098 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1099 goto error; 1100 } 1101 1102 1103 virtscsi_cmd_pool = 1104 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1105 virtscsi_cmd_cache); 1106 if (!virtscsi_cmd_pool) { 1107 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1108 goto error; 1109 } 1110 ret = register_virtio_driver(&virtio_scsi_driver); 1111 if (ret < 0) 1112 goto error; 1113 1114 return 0; 1115 1116 error: 1117 if (virtscsi_cmd_pool) { 1118 mempool_destroy(virtscsi_cmd_pool); 1119 virtscsi_cmd_pool = NULL; 1120 } 1121 if (virtscsi_cmd_cache) { 1122 kmem_cache_destroy(virtscsi_cmd_cache); 1123 virtscsi_cmd_cache = NULL; 1124 } 1125 return ret; 1126 } 1127 1128 static void __exit fini(void) 1129 { 1130 unregister_virtio_driver(&virtio_scsi_driver); 1131 mempool_destroy(virtscsi_cmd_pool); 1132 kmem_cache_destroy(virtscsi_cmd_cache); 1133 } 1134 module_init(init); 1135 module_exit(fini); 1136 1137 MODULE_DEVICE_TABLE(virtio, id_table); 1138 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1139 MODULE_LICENSE("GPL"); 1140