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 31 #define VIRTIO_SCSI_MEMPOOL_SZ 64 32 #define VIRTIO_SCSI_EVENT_LEN 8 33 #define VIRTIO_SCSI_VQ_BASE 2 34 35 /* Command queue element */ 36 struct virtio_scsi_cmd { 37 struct scsi_cmnd *sc; 38 struct completion *comp; 39 union { 40 struct virtio_scsi_cmd_req cmd; 41 struct virtio_scsi_cmd_req_pi cmd_pi; 42 struct virtio_scsi_ctrl_tmf_req tmf; 43 struct virtio_scsi_ctrl_an_req an; 44 } req; 45 union { 46 struct virtio_scsi_cmd_resp cmd; 47 struct virtio_scsi_ctrl_tmf_resp tmf; 48 struct virtio_scsi_ctrl_an_resp an; 49 struct virtio_scsi_event evt; 50 } resp; 51 } ____cacheline_aligned_in_smp; 52 53 struct virtio_scsi_event_node { 54 struct virtio_scsi *vscsi; 55 struct virtio_scsi_event event; 56 struct work_struct work; 57 }; 58 59 struct virtio_scsi_vq { 60 /* Protects vq */ 61 spinlock_t vq_lock; 62 63 struct virtqueue *vq; 64 }; 65 66 /* 67 * Per-target queue state. 68 * 69 * This struct holds the data needed by the queue steering policy. When a 70 * target is sent multiple requests, we need to drive them to the same queue so 71 * that FIFO processing order is kept. However, if a target was idle, we can 72 * choose a queue arbitrarily. In this case the queue is chosen according to 73 * the current VCPU, so the driver expects the number of request queues to be 74 * equal to the number of VCPUs. This makes it easy and fast to select the 75 * queue, and also lets the driver optimize the IRQ affinity for the virtqueues 76 * (each virtqueue's affinity is set to the CPU that "owns" the queue). 77 * 78 * tgt_lock is held to serialize reading and writing req_vq. Reading req_vq 79 * could be done locklessly, but we do not do it yet. 80 * 81 * Decrements of reqs are never concurrent with writes of req_vq: before the 82 * decrement reqs will be != 0; after the decrement the virtqueue completion 83 * routine will not use the req_vq so it can be changed by a new request. 84 * Thus they can happen outside the tgt_lock, provided of course we make reqs 85 * an atomic_t. 86 */ 87 struct virtio_scsi_target_state { 88 /* This spinlock never held at the same time as vq_lock. */ 89 spinlock_t tgt_lock; 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_complete_free(struct virtio_scsi *vscsi, void *buf) 241 { 242 struct virtio_scsi_cmd *cmd = buf; 243 244 if (cmd->comp) 245 complete_all(cmd->comp); 246 } 247 248 static void virtscsi_ctrl_done(struct virtqueue *vq) 249 { 250 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 251 struct virtio_scsi *vscsi = shost_priv(sh); 252 253 virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); 254 }; 255 256 static int virtscsi_kick_event(struct virtio_scsi *vscsi, 257 struct virtio_scsi_event_node *event_node) 258 { 259 int err; 260 struct scatterlist sg; 261 unsigned long flags; 262 263 sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); 264 265 spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); 266 267 err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, 268 GFP_ATOMIC); 269 if (!err) 270 virtqueue_kick(vscsi->event_vq.vq); 271 272 spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); 273 274 return err; 275 } 276 277 static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) 278 { 279 int i; 280 281 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { 282 vscsi->event_list[i].vscsi = vscsi; 283 virtscsi_kick_event(vscsi, &vscsi->event_list[i]); 284 } 285 286 return 0; 287 } 288 289 static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) 290 { 291 int i; 292 293 for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) 294 cancel_work_sync(&vscsi->event_list[i].work); 295 } 296 297 static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, 298 struct virtio_scsi_event *event) 299 { 300 struct scsi_device *sdev; 301 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 302 unsigned int target = event->lun[1]; 303 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 304 305 switch (event->reason) { 306 case VIRTIO_SCSI_EVT_RESET_RESCAN: 307 scsi_add_device(shost, 0, target, lun); 308 break; 309 case VIRTIO_SCSI_EVT_RESET_REMOVED: 310 sdev = scsi_device_lookup(shost, 0, target, lun); 311 if (sdev) { 312 scsi_remove_device(sdev); 313 scsi_device_put(sdev); 314 } else { 315 pr_err("SCSI device %d 0 %d %d not found\n", 316 shost->host_no, target, lun); 317 } 318 break; 319 default: 320 pr_info("Unsupport virtio scsi event reason %x\n", event->reason); 321 } 322 } 323 324 static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, 325 struct virtio_scsi_event *event) 326 { 327 struct scsi_device *sdev; 328 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 329 unsigned int target = event->lun[1]; 330 unsigned int lun = (event->lun[2] << 8) | event->lun[3]; 331 u8 asc = event->reason & 255; 332 u8 ascq = event->reason >> 8; 333 334 sdev = scsi_device_lookup(shost, 0, target, lun); 335 if (!sdev) { 336 pr_err("SCSI device %d 0 %d %d not found\n", 337 shost->host_no, target, lun); 338 return; 339 } 340 341 /* Handle "Parameters changed", "Mode parameters changed", and 342 "Capacity data has changed". */ 343 if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) 344 scsi_rescan_device(&sdev->sdev_gendev); 345 346 scsi_device_put(sdev); 347 } 348 349 static void virtscsi_handle_event(struct work_struct *work) 350 { 351 struct virtio_scsi_event_node *event_node = 352 container_of(work, struct virtio_scsi_event_node, work); 353 struct virtio_scsi *vscsi = event_node->vscsi; 354 struct virtio_scsi_event *event = &event_node->event; 355 356 if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) { 357 event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED; 358 scsi_scan_host(virtio_scsi_host(vscsi->vdev)); 359 } 360 361 switch (event->event) { 362 case VIRTIO_SCSI_T_NO_EVENT: 363 break; 364 case VIRTIO_SCSI_T_TRANSPORT_RESET: 365 virtscsi_handle_transport_reset(vscsi, event); 366 break; 367 case VIRTIO_SCSI_T_PARAM_CHANGE: 368 virtscsi_handle_param_change(vscsi, event); 369 break; 370 default: 371 pr_err("Unsupport virtio scsi event %x\n", event->event); 372 } 373 virtscsi_kick_event(vscsi, event_node); 374 } 375 376 static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) 377 { 378 struct virtio_scsi_event_node *event_node = buf; 379 380 INIT_WORK(&event_node->work, virtscsi_handle_event); 381 schedule_work(&event_node->work); 382 } 383 384 static void virtscsi_event_done(struct virtqueue *vq) 385 { 386 struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); 387 struct virtio_scsi *vscsi = shost_priv(sh); 388 389 virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); 390 }; 391 392 /** 393 * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue 394 * @vq : the struct virtqueue we're talking about 395 * @cmd : command structure 396 * @req_size : size of the request buffer 397 * @resp_size : size of the response buffer 398 */ 399 static int virtscsi_add_cmd(struct virtqueue *vq, 400 struct virtio_scsi_cmd *cmd, 401 size_t req_size, size_t resp_size) 402 { 403 struct scsi_cmnd *sc = cmd->sc; 404 struct scatterlist *sgs[6], req, resp; 405 struct sg_table *out, *in; 406 unsigned out_num = 0, in_num = 0; 407 408 out = in = NULL; 409 410 if (sc && sc->sc_data_direction != DMA_NONE) { 411 if (sc->sc_data_direction != DMA_FROM_DEVICE) 412 out = &scsi_out(sc)->table; 413 if (sc->sc_data_direction != DMA_TO_DEVICE) 414 in = &scsi_in(sc)->table; 415 } 416 417 /* Request header. */ 418 sg_init_one(&req, &cmd->req, req_size); 419 sgs[out_num++] = &req; 420 421 /* Data-out buffer. */ 422 if (out) { 423 /* Place WRITE protection SGLs before Data OUT payload */ 424 if (scsi_prot_sg_count(sc)) 425 sgs[out_num++] = scsi_prot_sglist(sc); 426 sgs[out_num++] = out->sgl; 427 } 428 429 /* Response header. */ 430 sg_init_one(&resp, &cmd->resp, resp_size); 431 sgs[out_num + in_num++] = &resp; 432 433 /* Data-in buffer */ 434 if (in) { 435 /* Place READ protection SGLs before Data IN payload */ 436 if (scsi_prot_sg_count(sc)) 437 sgs[out_num + in_num++] = scsi_prot_sglist(sc); 438 sgs[out_num + in_num++] = in->sgl; 439 } 440 441 return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); 442 } 443 444 static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, 445 struct virtio_scsi_cmd *cmd, 446 size_t req_size, size_t resp_size) 447 { 448 unsigned long flags; 449 int err; 450 bool needs_kick = false; 451 452 spin_lock_irqsave(&vq->vq_lock, flags); 453 err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size); 454 if (!err) 455 needs_kick = virtqueue_kick_prepare(vq->vq); 456 457 spin_unlock_irqrestore(&vq->vq_lock, flags); 458 459 if (needs_kick) 460 virtqueue_notify(vq->vq); 461 return err; 462 } 463 464 static void virtio_scsi_init_hdr(struct virtio_scsi_cmd_req *cmd, 465 struct scsi_cmnd *sc) 466 { 467 cmd->lun[0] = 1; 468 cmd->lun[1] = sc->device->id; 469 cmd->lun[2] = (sc->device->lun >> 8) | 0x40; 470 cmd->lun[3] = sc->device->lun & 0xff; 471 cmd->tag = (unsigned long)sc; 472 cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; 473 cmd->prio = 0; 474 cmd->crn = 0; 475 } 476 477 static void virtio_scsi_init_hdr_pi(struct virtio_scsi_cmd_req_pi *cmd_pi, 478 struct scsi_cmnd *sc) 479 { 480 struct request *rq = sc->request; 481 struct blk_integrity *bi; 482 483 virtio_scsi_init_hdr((struct virtio_scsi_cmd_req *)cmd_pi, sc); 484 485 if (!rq || !scsi_prot_sg_count(sc)) 486 return; 487 488 bi = blk_get_integrity(rq->rq_disk); 489 490 if (sc->sc_data_direction == DMA_TO_DEVICE) 491 cmd_pi->pi_bytesout = blk_rq_sectors(rq) * bi->tuple_size; 492 else if (sc->sc_data_direction == DMA_FROM_DEVICE) 493 cmd_pi->pi_bytesin = blk_rq_sectors(rq) * bi->tuple_size; 494 } 495 496 static int virtscsi_queuecommand(struct virtio_scsi *vscsi, 497 struct virtio_scsi_vq *req_vq, 498 struct scsi_cmnd *sc) 499 { 500 struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); 501 struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); 502 int req_size; 503 504 BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); 505 506 /* TODO: check feature bit and fail if unsupported? */ 507 BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); 508 509 dev_dbg(&sc->device->sdev_gendev, 510 "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); 511 512 memset(cmd, 0, sizeof(*cmd)); 513 cmd->sc = sc; 514 515 BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); 516 517 if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { 518 virtio_scsi_init_hdr_pi(&cmd->req.cmd_pi, sc); 519 memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); 520 req_size = sizeof(cmd->req.cmd_pi); 521 } else { 522 virtio_scsi_init_hdr(&cmd->req.cmd, sc); 523 memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); 524 req_size = sizeof(cmd->req.cmd); 525 } 526 527 if (virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)) != 0) 528 return SCSI_MLQUEUE_HOST_BUSY; 529 return 0; 530 } 531 532 static int virtscsi_queuecommand_single(struct Scsi_Host *sh, 533 struct scsi_cmnd *sc) 534 { 535 struct virtio_scsi *vscsi = shost_priv(sh); 536 struct virtio_scsi_target_state *tgt = 537 scsi_target(sc->device)->hostdata; 538 539 atomic_inc(&tgt->reqs); 540 return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); 541 } 542 543 static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, 544 struct virtio_scsi_target_state *tgt) 545 { 546 struct virtio_scsi_vq *vq; 547 unsigned long flags; 548 u32 queue_num; 549 550 spin_lock_irqsave(&tgt->tgt_lock, flags); 551 552 if (atomic_inc_return(&tgt->reqs) > 1) 553 vq = tgt->req_vq; 554 else { 555 queue_num = smp_processor_id(); 556 while (unlikely(queue_num >= vscsi->num_queues)) 557 queue_num -= vscsi->num_queues; 558 559 tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; 560 } 561 562 spin_unlock_irqrestore(&tgt->tgt_lock, flags); 563 return vq; 564 } 565 566 static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, 567 struct scsi_cmnd *sc) 568 { 569 struct virtio_scsi *vscsi = shost_priv(sh); 570 struct virtio_scsi_target_state *tgt = 571 scsi_target(sc->device)->hostdata; 572 struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt); 573 574 return virtscsi_queuecommand(vscsi, req_vq, sc); 575 } 576 577 static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) 578 { 579 DECLARE_COMPLETION_ONSTACK(comp); 580 int ret = FAILED; 581 582 cmd->comp = ∁ 583 if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, 584 sizeof cmd->req.tmf, sizeof cmd->resp.tmf) < 0) 585 goto out; 586 587 wait_for_completion(&comp); 588 if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || 589 cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) 590 ret = SUCCESS; 591 592 out: 593 mempool_free(cmd, virtscsi_cmd_pool); 594 return ret; 595 } 596 597 static int virtscsi_device_reset(struct scsi_cmnd *sc) 598 { 599 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 600 struct virtio_scsi_cmd *cmd; 601 602 sdev_printk(KERN_INFO, sc->device, "device reset\n"); 603 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 604 if (!cmd) 605 return FAILED; 606 607 memset(cmd, 0, sizeof(*cmd)); 608 cmd->sc = sc; 609 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 610 .type = VIRTIO_SCSI_T_TMF, 611 .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET, 612 .lun[0] = 1, 613 .lun[1] = sc->device->id, 614 .lun[2] = (sc->device->lun >> 8) | 0x40, 615 .lun[3] = sc->device->lun & 0xff, 616 }; 617 return virtscsi_tmf(vscsi, cmd); 618 } 619 620 static int virtscsi_abort(struct scsi_cmnd *sc) 621 { 622 struct virtio_scsi *vscsi = shost_priv(sc->device->host); 623 struct virtio_scsi_cmd *cmd; 624 625 scmd_printk(KERN_INFO, sc, "abort\n"); 626 cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); 627 if (!cmd) 628 return FAILED; 629 630 memset(cmd, 0, sizeof(*cmd)); 631 cmd->sc = sc; 632 cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ 633 .type = VIRTIO_SCSI_T_TMF, 634 .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, 635 .lun[0] = 1, 636 .lun[1] = sc->device->id, 637 .lun[2] = (sc->device->lun >> 8) | 0x40, 638 .lun[3] = sc->device->lun & 0xff, 639 .tag = (unsigned long)sc, 640 }; 641 return virtscsi_tmf(vscsi, cmd); 642 } 643 644 static int virtscsi_target_alloc(struct scsi_target *starget) 645 { 646 struct virtio_scsi_target_state *tgt = 647 kmalloc(sizeof(*tgt), GFP_KERNEL); 648 if (!tgt) 649 return -ENOMEM; 650 651 spin_lock_init(&tgt->tgt_lock); 652 atomic_set(&tgt->reqs, 0); 653 tgt->req_vq = NULL; 654 655 starget->hostdata = tgt; 656 return 0; 657 } 658 659 static void virtscsi_target_destroy(struct scsi_target *starget) 660 { 661 struct virtio_scsi_target_state *tgt = starget->hostdata; 662 kfree(tgt); 663 } 664 665 static struct scsi_host_template virtscsi_host_template_single = { 666 .module = THIS_MODULE, 667 .name = "Virtio SCSI HBA", 668 .proc_name = "virtio_scsi", 669 .this_id = -1, 670 .cmd_size = sizeof(struct virtio_scsi_cmd), 671 .queuecommand = virtscsi_queuecommand_single, 672 .eh_abort_handler = virtscsi_abort, 673 .eh_device_reset_handler = virtscsi_device_reset, 674 675 .can_queue = 1024, 676 .dma_boundary = UINT_MAX, 677 .use_clustering = ENABLE_CLUSTERING, 678 .target_alloc = virtscsi_target_alloc, 679 .target_destroy = virtscsi_target_destroy, 680 }; 681 682 static struct scsi_host_template virtscsi_host_template_multi = { 683 .module = THIS_MODULE, 684 .name = "Virtio SCSI HBA", 685 .proc_name = "virtio_scsi", 686 .this_id = -1, 687 .cmd_size = sizeof(struct virtio_scsi_cmd), 688 .queuecommand = virtscsi_queuecommand_multi, 689 .eh_abort_handler = virtscsi_abort, 690 .eh_device_reset_handler = virtscsi_device_reset, 691 692 .can_queue = 1024, 693 .dma_boundary = UINT_MAX, 694 .use_clustering = ENABLE_CLUSTERING, 695 .target_alloc = virtscsi_target_alloc, 696 .target_destroy = virtscsi_target_destroy, 697 }; 698 699 #define virtscsi_config_get(vdev, fld) \ 700 ({ \ 701 typeof(((struct virtio_scsi_config *)0)->fld) __val; \ 702 virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ 703 __val; \ 704 }) 705 706 #define virtscsi_config_set(vdev, fld, val) \ 707 do { \ 708 typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ 709 virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ 710 } while(0) 711 712 static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 713 { 714 int i; 715 int cpu; 716 717 /* In multiqueue mode, when the number of cpu is equal 718 * to the number of request queues, we let the qeueues 719 * to be private to one cpu by setting the affinity hint 720 * to eliminate the contention. 721 */ 722 if ((vscsi->num_queues == 1 || 723 vscsi->num_queues != num_online_cpus()) && affinity) { 724 if (vscsi->affinity_hint_set) 725 affinity = false; 726 else 727 return; 728 } 729 730 if (affinity) { 731 i = 0; 732 for_each_online_cpu(cpu) { 733 virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu); 734 i++; 735 } 736 737 vscsi->affinity_hint_set = true; 738 } else { 739 for (i = 0; i < vscsi->num_queues; i++) { 740 if (!vscsi->req_vqs[i].vq) 741 continue; 742 743 virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); 744 } 745 746 vscsi->affinity_hint_set = false; 747 } 748 } 749 750 static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) 751 { 752 get_online_cpus(); 753 __virtscsi_set_affinity(vscsi, affinity); 754 put_online_cpus(); 755 } 756 757 static int virtscsi_cpu_callback(struct notifier_block *nfb, 758 unsigned long action, void *hcpu) 759 { 760 struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb); 761 switch(action) { 762 case CPU_ONLINE: 763 case CPU_ONLINE_FROZEN: 764 case CPU_DEAD: 765 case CPU_DEAD_FROZEN: 766 __virtscsi_set_affinity(vscsi, true); 767 break; 768 default: 769 break; 770 } 771 return NOTIFY_OK; 772 } 773 774 static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, 775 struct virtqueue *vq) 776 { 777 spin_lock_init(&virtscsi_vq->vq_lock); 778 virtscsi_vq->vq = vq; 779 } 780 781 static void virtscsi_scan(struct virtio_device *vdev) 782 { 783 struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv; 784 785 scsi_scan_host(shost); 786 } 787 788 static void virtscsi_remove_vqs(struct virtio_device *vdev) 789 { 790 struct Scsi_Host *sh = virtio_scsi_host(vdev); 791 struct virtio_scsi *vscsi = shost_priv(sh); 792 793 virtscsi_set_affinity(vscsi, false); 794 795 /* Stop all the virtqueues. */ 796 vdev->config->reset(vdev); 797 798 vdev->config->del_vqs(vdev); 799 } 800 801 static int virtscsi_init(struct virtio_device *vdev, 802 struct virtio_scsi *vscsi) 803 { 804 int err; 805 u32 i; 806 u32 num_vqs; 807 vq_callback_t **callbacks; 808 const char **names; 809 struct virtqueue **vqs; 810 811 num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; 812 vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); 813 callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL); 814 names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL); 815 816 if (!callbacks || !vqs || !names) { 817 err = -ENOMEM; 818 goto out; 819 } 820 821 callbacks[0] = virtscsi_ctrl_done; 822 callbacks[1] = virtscsi_event_done; 823 names[0] = "control"; 824 names[1] = "event"; 825 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { 826 callbacks[i] = virtscsi_req_done; 827 names[i] = "request"; 828 } 829 830 /* Discover virtqueues and write information to configuration. */ 831 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); 832 if (err) 833 goto out; 834 835 virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); 836 virtscsi_init_vq(&vscsi->event_vq, vqs[1]); 837 for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) 838 virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], 839 vqs[i]); 840 841 virtscsi_set_affinity(vscsi, true); 842 843 virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); 844 virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); 845 846 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 847 virtscsi_kick_event_all(vscsi); 848 849 err = 0; 850 851 out: 852 kfree(names); 853 kfree(callbacks); 854 kfree(vqs); 855 if (err) 856 virtscsi_remove_vqs(vdev); 857 return err; 858 } 859 860 static int virtscsi_probe(struct virtio_device *vdev) 861 { 862 struct Scsi_Host *shost; 863 struct virtio_scsi *vscsi; 864 int err, host_prot; 865 u32 sg_elems, num_targets; 866 u32 cmd_per_lun; 867 u32 num_queues; 868 struct scsi_host_template *hostt; 869 870 /* We need to know how many queues before we allocate. */ 871 num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; 872 873 num_targets = virtscsi_config_get(vdev, max_target) + 1; 874 875 if (num_queues == 1) 876 hostt = &virtscsi_host_template_single; 877 else 878 hostt = &virtscsi_host_template_multi; 879 880 shost = scsi_host_alloc(hostt, 881 sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); 882 if (!shost) 883 return -ENOMEM; 884 885 sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; 886 shost->sg_tablesize = sg_elems; 887 vscsi = shost_priv(shost); 888 vscsi->vdev = vdev; 889 vscsi->num_queues = num_queues; 890 vdev->priv = shost; 891 892 err = virtscsi_init(vdev, vscsi); 893 if (err) 894 goto virtscsi_init_failed; 895 896 vscsi->nb.notifier_call = &virtscsi_cpu_callback; 897 err = register_hotcpu_notifier(&vscsi->nb); 898 if (err) { 899 pr_err("registering cpu notifier failed\n"); 900 goto scsi_add_host_failed; 901 } 902 903 cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; 904 shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); 905 shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; 906 907 /* LUNs > 256 are reported with format 1, so they go in the range 908 * 16640-32767. 909 */ 910 shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; 911 shost->max_id = num_targets; 912 shost->max_channel = 0; 913 shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; 914 915 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { 916 host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | 917 SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | 918 SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; 919 920 scsi_host_set_prot(shost, host_prot); 921 scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); 922 } 923 924 err = scsi_add_host(shost, &vdev->dev); 925 if (err) 926 goto scsi_add_host_failed; 927 /* 928 * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan() 929 * after VIRTIO_CONFIG_S_DRIVER_OK has been set.. 930 */ 931 return 0; 932 933 scsi_add_host_failed: 934 vdev->config->del_vqs(vdev); 935 virtscsi_init_failed: 936 scsi_host_put(shost); 937 return err; 938 } 939 940 static void virtscsi_remove(struct virtio_device *vdev) 941 { 942 struct Scsi_Host *shost = virtio_scsi_host(vdev); 943 struct virtio_scsi *vscsi = shost_priv(shost); 944 945 if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) 946 virtscsi_cancel_event_work(vscsi); 947 948 scsi_remove_host(shost); 949 950 unregister_hotcpu_notifier(&vscsi->nb); 951 952 virtscsi_remove_vqs(vdev); 953 scsi_host_put(shost); 954 } 955 956 #ifdef CONFIG_PM_SLEEP 957 static int virtscsi_freeze(struct virtio_device *vdev) 958 { 959 struct Scsi_Host *sh = virtio_scsi_host(vdev); 960 struct virtio_scsi *vscsi = shost_priv(sh); 961 962 unregister_hotcpu_notifier(&vscsi->nb); 963 virtscsi_remove_vqs(vdev); 964 return 0; 965 } 966 967 static int virtscsi_restore(struct virtio_device *vdev) 968 { 969 struct Scsi_Host *sh = virtio_scsi_host(vdev); 970 struct virtio_scsi *vscsi = shost_priv(sh); 971 int err; 972 973 err = virtscsi_init(vdev, vscsi); 974 if (err) 975 return err; 976 977 err = register_hotcpu_notifier(&vscsi->nb); 978 if (err) 979 vdev->config->del_vqs(vdev); 980 981 return err; 982 } 983 #endif 984 985 static struct virtio_device_id id_table[] = { 986 { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, 987 { 0 }, 988 }; 989 990 static unsigned int features[] = { 991 VIRTIO_SCSI_F_HOTPLUG, 992 VIRTIO_SCSI_F_CHANGE, 993 VIRTIO_SCSI_F_T10_PI, 994 }; 995 996 static struct virtio_driver virtio_scsi_driver = { 997 .feature_table = features, 998 .feature_table_size = ARRAY_SIZE(features), 999 .driver.name = KBUILD_MODNAME, 1000 .driver.owner = THIS_MODULE, 1001 .id_table = id_table, 1002 .probe = virtscsi_probe, 1003 .scan = virtscsi_scan, 1004 #ifdef CONFIG_PM_SLEEP 1005 .freeze = virtscsi_freeze, 1006 .restore = virtscsi_restore, 1007 #endif 1008 .remove = virtscsi_remove, 1009 }; 1010 1011 static int __init init(void) 1012 { 1013 int ret = -ENOMEM; 1014 1015 virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); 1016 if (!virtscsi_cmd_cache) { 1017 pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); 1018 goto error; 1019 } 1020 1021 1022 virtscsi_cmd_pool = 1023 mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, 1024 virtscsi_cmd_cache); 1025 if (!virtscsi_cmd_pool) { 1026 pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); 1027 goto error; 1028 } 1029 ret = register_virtio_driver(&virtio_scsi_driver); 1030 if (ret < 0) 1031 goto error; 1032 1033 return 0; 1034 1035 error: 1036 if (virtscsi_cmd_pool) { 1037 mempool_destroy(virtscsi_cmd_pool); 1038 virtscsi_cmd_pool = NULL; 1039 } 1040 if (virtscsi_cmd_cache) { 1041 kmem_cache_destroy(virtscsi_cmd_cache); 1042 virtscsi_cmd_cache = NULL; 1043 } 1044 return ret; 1045 } 1046 1047 static void __exit fini(void) 1048 { 1049 unregister_virtio_driver(&virtio_scsi_driver); 1050 mempool_destroy(virtscsi_cmd_pool); 1051 kmem_cache_destroy(virtscsi_cmd_cache); 1052 } 1053 module_init(init); 1054 module_exit(fini); 1055 1056 MODULE_DEVICE_TABLE(virtio, id_table); 1057 MODULE_DESCRIPTION("Virtio SCSI HBA driver"); 1058 MODULE_LICENSE("GPL"); 1059