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