/* * Virtio SCSI HBA driver * * Copyright IBM Corp. 2010 * Copyright Red Hat, Inc. 2011 * * Authors: * Stefan Hajnoczi * Paolo Bonzini * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #define VIRTIO_SCSI_MEMPOOL_SZ 64 #define VIRTIO_SCSI_EVENT_LEN 8 #define VIRTIO_SCSI_VQ_BASE 2 /* Command queue element */ struct virtio_scsi_cmd { struct scsi_cmnd *sc; struct completion *comp; union { struct virtio_scsi_cmd_req cmd; struct virtio_scsi_ctrl_tmf_req tmf; struct virtio_scsi_ctrl_an_req an; } req; union { struct virtio_scsi_cmd_resp cmd; struct virtio_scsi_ctrl_tmf_resp tmf; struct virtio_scsi_ctrl_an_resp an; struct virtio_scsi_event evt; } resp; } ____cacheline_aligned_in_smp; struct virtio_scsi_event_node { struct virtio_scsi *vscsi; struct virtio_scsi_event event; struct work_struct work; }; struct virtio_scsi_vq { /* Protects vq */ spinlock_t vq_lock; struct virtqueue *vq; }; /* * Per-target queue state. * * This struct holds the data needed by the queue steering policy. When a * target is sent multiple requests, we need to drive them to the same queue so * that FIFO processing order is kept. However, if a target was idle, we can * choose a queue arbitrarily. In this case the queue is chosen according to * the current VCPU, so the driver expects the number of request queues to be * equal to the number of VCPUs. This makes it easy and fast to select the * queue, and also lets the driver optimize the IRQ affinity for the virtqueues * (each virtqueue's affinity is set to the CPU that "owns" the queue). * * An interesting effect of this policy is that only writes to req_vq need to * take the tgt_lock. Read can be done outside the lock because: * * - writes of req_vq only occur when atomic_inc_return(&tgt->reqs) returns 1. * In that case, no other CPU is reading req_vq: even if they were in * virtscsi_queuecommand_multi, they would be spinning on tgt_lock. * * - reads of req_vq only occur when the target is not idle (reqs != 0). * A CPU that enters virtscsi_queuecommand_multi will not modify req_vq. * * Similarly, decrements of reqs are never concurrent with writes of req_vq. * Thus they can happen outside the tgt_lock, provided of course we make reqs * an atomic_t. */ struct virtio_scsi_target_state { /* This spinlock never held at the same time as vq_lock. */ spinlock_t tgt_lock; /* Count of outstanding requests. */ atomic_t reqs; /* Currently active virtqueue for requests sent to this target. */ struct virtio_scsi_vq *req_vq; }; /* Driver instance state */ struct virtio_scsi { struct virtio_device *vdev; /* Get some buffers ready for event vq */ struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN]; u32 num_queues; /* If the affinity hint is set for virtqueues */ bool affinity_hint_set; /* CPU hotplug notifier */ struct notifier_block nb; struct virtio_scsi_vq ctrl_vq; struct virtio_scsi_vq event_vq; struct virtio_scsi_vq req_vqs[]; }; static struct kmem_cache *virtscsi_cmd_cache; static mempool_t *virtscsi_cmd_pool; static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev) { return vdev->priv; } static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid) { if (!resid) return; if (!scsi_bidi_cmnd(sc)) { scsi_set_resid(sc, resid); return; } scsi_in(sc)->resid = min(resid, scsi_in(sc)->length); scsi_out(sc)->resid = resid - scsi_in(sc)->resid; } /** * virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done * * Called with vq_lock held. */ static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf) { struct virtio_scsi_cmd *cmd = buf; struct scsi_cmnd *sc = cmd->sc; struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd; struct virtio_scsi_target_state *tgt = scsi_target(sc->device)->hostdata; dev_dbg(&sc->device->sdev_gendev, "cmd %p response %u status %#02x sense_len %u\n", sc, resp->response, resp->status, resp->sense_len); sc->result = resp->status; virtscsi_compute_resid(sc, resp->resid); switch (resp->response) { case VIRTIO_SCSI_S_OK: set_host_byte(sc, DID_OK); break; case VIRTIO_SCSI_S_OVERRUN: set_host_byte(sc, DID_ERROR); break; case VIRTIO_SCSI_S_ABORTED: set_host_byte(sc, DID_ABORT); break; case VIRTIO_SCSI_S_BAD_TARGET: set_host_byte(sc, DID_BAD_TARGET); break; case VIRTIO_SCSI_S_RESET: set_host_byte(sc, DID_RESET); break; case VIRTIO_SCSI_S_BUSY: set_host_byte(sc, DID_BUS_BUSY); break; case VIRTIO_SCSI_S_TRANSPORT_FAILURE: set_host_byte(sc, DID_TRANSPORT_DISRUPTED); break; case VIRTIO_SCSI_S_TARGET_FAILURE: set_host_byte(sc, DID_TARGET_FAILURE); break; case VIRTIO_SCSI_S_NEXUS_FAILURE: set_host_byte(sc, DID_NEXUS_FAILURE); break; default: scmd_printk(KERN_WARNING, sc, "Unknown response %d", resp->response); /* fall through */ case VIRTIO_SCSI_S_FAILURE: set_host_byte(sc, DID_ERROR); break; } WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE); if (sc->sense_buffer) { memcpy(sc->sense_buffer, resp->sense, min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE)); if (resp->sense_len) set_driver_byte(sc, DRIVER_SENSE); } mempool_free(cmd, virtscsi_cmd_pool); sc->scsi_done(sc); atomic_dec(&tgt->reqs); } static void virtscsi_vq_done(struct virtio_scsi *vscsi, struct virtio_scsi_vq *virtscsi_vq, void (*fn)(struct virtio_scsi *vscsi, void *buf)) { void *buf; unsigned int len; unsigned long flags; struct virtqueue *vq = virtscsi_vq->vq; spin_lock_irqsave(&virtscsi_vq->vq_lock, flags); do { virtqueue_disable_cb(vq); while ((buf = virtqueue_get_buf(vq, &len)) != NULL) fn(vscsi, buf); } while (!virtqueue_enable_cb(vq)); spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags); } static void virtscsi_req_done(struct virtqueue *vq) { struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); struct virtio_scsi *vscsi = shost_priv(sh); int index = vq->index - VIRTIO_SCSI_VQ_BASE; struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index]; /* * Read req_vq before decrementing the reqs field in * virtscsi_complete_cmd. * * With barriers: * * CPU #0 virtscsi_queuecommand_multi (CPU #1) * ------------------------------------------------------------ * lock vq_lock * read req_vq * read reqs (reqs = 1) * write reqs (reqs = 0) * increment reqs (reqs = 1) * write req_vq * * Possible reordering without barriers: * * CPU #0 virtscsi_queuecommand_multi (CPU #1) * ------------------------------------------------------------ * lock vq_lock * read reqs (reqs = 1) * write reqs (reqs = 0) * increment reqs (reqs = 1) * write req_vq * read (wrong) req_vq * * We do not need a full smp_rmb, because req_vq is required to get * to tgt->reqs: tgt is &vscsi->tgt[sc->device->id], where sc is stored * in the virtqueue as the user token. */ smp_read_barrier_depends(); virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); }; static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) { struct virtio_scsi_cmd *cmd = buf; if (cmd->comp) complete_all(cmd->comp); else mempool_free(cmd, virtscsi_cmd_pool); } static void virtscsi_ctrl_done(struct virtqueue *vq) { struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); struct virtio_scsi *vscsi = shost_priv(sh); virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free); }; static int virtscsi_kick_event(struct virtio_scsi *vscsi, struct virtio_scsi_event_node *event_node) { int err; struct scatterlist sg; unsigned long flags; sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event)); spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags); err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node, GFP_ATOMIC); if (!err) virtqueue_kick(vscsi->event_vq.vq); spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags); return err; } static int virtscsi_kick_event_all(struct virtio_scsi *vscsi) { int i; for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) { vscsi->event_list[i].vscsi = vscsi; virtscsi_kick_event(vscsi, &vscsi->event_list[i]); } return 0; } static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi) { int i; for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) cancel_work_sync(&vscsi->event_list[i].work); } static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi, struct virtio_scsi_event *event) { struct scsi_device *sdev; struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); unsigned int target = event->lun[1]; unsigned int lun = (event->lun[2] << 8) | event->lun[3]; switch (event->reason) { case VIRTIO_SCSI_EVT_RESET_RESCAN: scsi_add_device(shost, 0, target, lun); break; case VIRTIO_SCSI_EVT_RESET_REMOVED: sdev = scsi_device_lookup(shost, 0, target, lun); if (sdev) { scsi_remove_device(sdev); scsi_device_put(sdev); } else { pr_err("SCSI device %d 0 %d %d not found\n", shost->host_no, target, lun); } break; default: pr_info("Unsupport virtio scsi event reason %x\n", event->reason); } } static void virtscsi_handle_param_change(struct virtio_scsi *vscsi, struct virtio_scsi_event *event) { struct scsi_device *sdev; struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); unsigned int target = event->lun[1]; unsigned int lun = (event->lun[2] << 8) | event->lun[3]; u8 asc = event->reason & 255; u8 ascq = event->reason >> 8; sdev = scsi_device_lookup(shost, 0, target, lun); if (!sdev) { pr_err("SCSI device %d 0 %d %d not found\n", shost->host_no, target, lun); return; } /* Handle "Parameters changed", "Mode parameters changed", and "Capacity data has changed". */ if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09)) scsi_rescan_device(&sdev->sdev_gendev); scsi_device_put(sdev); } static void virtscsi_handle_event(struct work_struct *work) { struct virtio_scsi_event_node *event_node = container_of(work, struct virtio_scsi_event_node, work); struct virtio_scsi *vscsi = event_node->vscsi; struct virtio_scsi_event *event = &event_node->event; if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) { event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED; scsi_scan_host(virtio_scsi_host(vscsi->vdev)); } switch (event->event) { case VIRTIO_SCSI_T_NO_EVENT: break; case VIRTIO_SCSI_T_TRANSPORT_RESET: virtscsi_handle_transport_reset(vscsi, event); break; case VIRTIO_SCSI_T_PARAM_CHANGE: virtscsi_handle_param_change(vscsi, event); break; default: pr_err("Unsupport virtio scsi event %x\n", event->event); } virtscsi_kick_event(vscsi, event_node); } static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf) { struct virtio_scsi_event_node *event_node = buf; INIT_WORK(&event_node->work, virtscsi_handle_event); schedule_work(&event_node->work); } static void virtscsi_event_done(struct virtqueue *vq) { struct Scsi_Host *sh = virtio_scsi_host(vq->vdev); struct virtio_scsi *vscsi = shost_priv(sh); virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event); }; /** * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue * @vq : the struct virtqueue we're talking about * @cmd : command structure * @req_size : size of the request buffer * @resp_size : size of the response buffer * @gfp : flags to use for memory allocations */ static int virtscsi_add_cmd(struct virtqueue *vq, struct virtio_scsi_cmd *cmd, size_t req_size, size_t resp_size, gfp_t gfp) { struct scsi_cmnd *sc = cmd->sc; struct scatterlist *sgs[4], req, resp; struct sg_table *out, *in; unsigned out_num = 0, in_num = 0; out = in = NULL; if (sc && sc->sc_data_direction != DMA_NONE) { if (sc->sc_data_direction != DMA_FROM_DEVICE) out = &scsi_out(sc)->table; if (sc->sc_data_direction != DMA_TO_DEVICE) in = &scsi_in(sc)->table; } /* Request header. */ sg_init_one(&req, &cmd->req, req_size); sgs[out_num++] = &req; /* Data-out buffer. */ if (out) sgs[out_num++] = out->sgl; /* Response header. */ sg_init_one(&resp, &cmd->resp, resp_size); sgs[out_num + in_num++] = &resp; /* Data-in buffer */ if (in) sgs[out_num + in_num++] = in->sgl; return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp); } static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, struct virtio_scsi_cmd *cmd, size_t req_size, size_t resp_size, gfp_t gfp) { unsigned long flags; int err; bool needs_kick = false; spin_lock_irqsave(&vq->vq_lock, flags); err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp); if (!err) needs_kick = virtqueue_kick_prepare(vq->vq); spin_unlock_irqrestore(&vq->vq_lock, flags); if (needs_kick) virtqueue_notify(vq->vq); return err; } static int virtscsi_queuecommand(struct virtio_scsi *vscsi, struct virtio_scsi_vq *req_vq, struct scsi_cmnd *sc) { struct virtio_scsi_cmd *cmd; int ret; struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev); BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize); /* TODO: check feature bit and fail if unsupported? */ BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL); dev_dbg(&sc->device->sdev_gendev, "cmd %p CDB: %#02x\n", sc, sc->cmnd[0]); ret = SCSI_MLQUEUE_HOST_BUSY; cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC); if (!cmd) goto out; memset(cmd, 0, sizeof(*cmd)); cmd->sc = sc; cmd->req.cmd = (struct virtio_scsi_cmd_req){ .lun[0] = 1, .lun[1] = sc->device->id, .lun[2] = (sc->device->lun >> 8) | 0x40, .lun[3] = sc->device->lun & 0xff, .tag = (unsigned long)sc, .task_attr = VIRTIO_SCSI_S_SIMPLE, .prio = 0, .crn = 0, }; BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); if (virtscsi_kick_cmd(req_vq, cmd, sizeof cmd->req.cmd, sizeof cmd->resp.cmd, GFP_ATOMIC) == 0) ret = 0; else mempool_free(cmd, virtscsi_cmd_pool); out: return ret; } static int virtscsi_queuecommand_single(struct Scsi_Host *sh, struct scsi_cmnd *sc) { struct virtio_scsi *vscsi = shost_priv(sh); struct virtio_scsi_target_state *tgt = scsi_target(sc->device)->hostdata; atomic_inc(&tgt->reqs); return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc); } static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi, struct virtio_scsi_target_state *tgt) { struct virtio_scsi_vq *vq; unsigned long flags; u32 queue_num; spin_lock_irqsave(&tgt->tgt_lock, flags); /* * The memory barrier after atomic_inc_return matches * the smp_read_barrier_depends() in virtscsi_req_done. */ if (atomic_inc_return(&tgt->reqs) > 1) vq = ACCESS_ONCE(tgt->req_vq); else { queue_num = smp_processor_id(); while (unlikely(queue_num >= vscsi->num_queues)) queue_num -= vscsi->num_queues; tgt->req_vq = vq = &vscsi->req_vqs[queue_num]; } spin_unlock_irqrestore(&tgt->tgt_lock, flags); return vq; } static int virtscsi_queuecommand_multi(struct Scsi_Host *sh, struct scsi_cmnd *sc) { struct virtio_scsi *vscsi = shost_priv(sh); struct virtio_scsi_target_state *tgt = scsi_target(sc->device)->hostdata; struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt); return virtscsi_queuecommand(vscsi, req_vq, sc); } static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd) { DECLARE_COMPLETION_ONSTACK(comp); int ret = FAILED; cmd->comp = ∁ if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd, sizeof cmd->req.tmf, sizeof cmd->resp.tmf, GFP_NOIO) < 0) goto out; wait_for_completion(&comp); if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK || cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) ret = SUCCESS; out: mempool_free(cmd, virtscsi_cmd_pool); return ret; } static int virtscsi_device_reset(struct scsi_cmnd *sc) { struct virtio_scsi *vscsi = shost_priv(sc->device->host); struct virtio_scsi_cmd *cmd; sdev_printk(KERN_INFO, sc->device, "device reset\n"); cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); if (!cmd) return FAILED; memset(cmd, 0, sizeof(*cmd)); cmd->sc = sc; cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ .type = VIRTIO_SCSI_T_TMF, .subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET, .lun[0] = 1, .lun[1] = sc->device->id, .lun[2] = (sc->device->lun >> 8) | 0x40, .lun[3] = sc->device->lun & 0xff, }; return virtscsi_tmf(vscsi, cmd); } static int virtscsi_abort(struct scsi_cmnd *sc) { struct virtio_scsi *vscsi = shost_priv(sc->device->host); struct virtio_scsi_cmd *cmd; scmd_printk(KERN_INFO, sc, "abort\n"); cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO); if (!cmd) return FAILED; memset(cmd, 0, sizeof(*cmd)); cmd->sc = sc; cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ .type = VIRTIO_SCSI_T_TMF, .subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK, .lun[0] = 1, .lun[1] = sc->device->id, .lun[2] = (sc->device->lun >> 8) | 0x40, .lun[3] = sc->device->lun & 0xff, .tag = (unsigned long)sc, }; return virtscsi_tmf(vscsi, cmd); } static int virtscsi_target_alloc(struct scsi_target *starget) { struct virtio_scsi_target_state *tgt = kmalloc(sizeof(*tgt), GFP_KERNEL); if (!tgt) return -ENOMEM; spin_lock_init(&tgt->tgt_lock); atomic_set(&tgt->reqs, 0); tgt->req_vq = NULL; starget->hostdata = tgt; return 0; } static void virtscsi_target_destroy(struct scsi_target *starget) { struct virtio_scsi_target_state *tgt = starget->hostdata; kfree(tgt); } static struct scsi_host_template virtscsi_host_template_single = { .module = THIS_MODULE, .name = "Virtio SCSI HBA", .proc_name = "virtio_scsi", .this_id = -1, .queuecommand = virtscsi_queuecommand_single, .eh_abort_handler = virtscsi_abort, .eh_device_reset_handler = virtscsi_device_reset, .can_queue = 1024, .dma_boundary = UINT_MAX, .use_clustering = ENABLE_CLUSTERING, .target_alloc = virtscsi_target_alloc, .target_destroy = virtscsi_target_destroy, }; static struct scsi_host_template virtscsi_host_template_multi = { .module = THIS_MODULE, .name = "Virtio SCSI HBA", .proc_name = "virtio_scsi", .this_id = -1, .queuecommand = virtscsi_queuecommand_multi, .eh_abort_handler = virtscsi_abort, .eh_device_reset_handler = virtscsi_device_reset, .can_queue = 1024, .dma_boundary = UINT_MAX, .use_clustering = ENABLE_CLUSTERING, .target_alloc = virtscsi_target_alloc, .target_destroy = virtscsi_target_destroy, }; #define virtscsi_config_get(vdev, fld) \ ({ \ typeof(((struct virtio_scsi_config *)0)->fld) __val; \ virtio_cread(vdev, struct virtio_scsi_config, fld, &__val); \ __val; \ }) #define virtscsi_config_set(vdev, fld, val) \ do { \ typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \ virtio_cwrite(vdev, struct virtio_scsi_config, fld, &__val); \ } while(0) static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) { int i; int cpu; /* In multiqueue mode, when the number of cpu is equal * to the number of request queues, we let the qeueues * to be private to one cpu by setting the affinity hint * to eliminate the contention. */ if ((vscsi->num_queues == 1 || vscsi->num_queues != num_online_cpus()) && affinity) { if (vscsi->affinity_hint_set) affinity = false; else return; } if (affinity) { i = 0; for_each_online_cpu(cpu) { virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu); i++; } vscsi->affinity_hint_set = true; } else { for (i = 0; i < vscsi->num_queues; i++) virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1); vscsi->affinity_hint_set = false; } } static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity) { get_online_cpus(); __virtscsi_set_affinity(vscsi, affinity); put_online_cpus(); } static int virtscsi_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) { struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb); switch(action) { case CPU_ONLINE: case CPU_ONLINE_FROZEN: case CPU_DEAD: case CPU_DEAD_FROZEN: __virtscsi_set_affinity(vscsi, true); break; default: break; } return NOTIFY_OK; } static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq, struct virtqueue *vq) { spin_lock_init(&virtscsi_vq->vq_lock); virtscsi_vq->vq = vq; } static void virtscsi_scan(struct virtio_device *vdev) { struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv; scsi_scan_host(shost); } static void virtscsi_remove_vqs(struct virtio_device *vdev) { struct Scsi_Host *sh = virtio_scsi_host(vdev); struct virtio_scsi *vscsi = shost_priv(sh); virtscsi_set_affinity(vscsi, false); /* Stop all the virtqueues. */ vdev->config->reset(vdev); vdev->config->del_vqs(vdev); } static int virtscsi_init(struct virtio_device *vdev, struct virtio_scsi *vscsi) { int err; u32 i; u32 num_vqs; vq_callback_t **callbacks; const char **names; struct virtqueue **vqs; num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL); callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL); names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL); if (!callbacks || !vqs || !names) { err = -ENOMEM; goto out; } callbacks[0] = virtscsi_ctrl_done; callbacks[1] = virtscsi_event_done; names[0] = "control"; names[1] = "event"; for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) { callbacks[i] = virtscsi_req_done; names[i] = "request"; } /* Discover virtqueues and write information to configuration. */ err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); if (err) goto out; virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]); virtscsi_init_vq(&vscsi->event_vq, vqs[1]); for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE], vqs[i]); virtscsi_set_affinity(vscsi, true); virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) virtscsi_kick_event_all(vscsi); err = 0; out: kfree(names); kfree(callbacks); kfree(vqs); if (err) virtscsi_remove_vqs(vdev); return err; } static int virtscsi_probe(struct virtio_device *vdev) { struct Scsi_Host *shost; struct virtio_scsi *vscsi; int err; u32 sg_elems, num_targets; u32 cmd_per_lun; u32 num_queues; struct scsi_host_template *hostt; /* We need to know how many queues before we allocate. */ num_queues = virtscsi_config_get(vdev, num_queues) ? : 1; num_targets = virtscsi_config_get(vdev, max_target) + 1; if (num_queues == 1) hostt = &virtscsi_host_template_single; else hostt = &virtscsi_host_template_multi; shost = scsi_host_alloc(hostt, sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); if (!shost) return -ENOMEM; sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1; shost->sg_tablesize = sg_elems; vscsi = shost_priv(shost); vscsi->vdev = vdev; vscsi->num_queues = num_queues; vdev->priv = shost; err = virtscsi_init(vdev, vscsi); if (err) goto virtscsi_init_failed; vscsi->nb.notifier_call = &virtscsi_cpu_callback; err = register_hotcpu_notifier(&vscsi->nb); if (err) { pr_err("registering cpu notifier failed\n"); goto scsi_add_host_failed; } cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1; shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue); shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF; /* LUNs > 256 are reported with format 1, so they go in the range * 16640-32767. */ shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000; shost->max_id = num_targets; shost->max_channel = 0; shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE; err = scsi_add_host(shost, &vdev->dev); if (err) goto scsi_add_host_failed; /* * scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan() * after VIRTIO_CONFIG_S_DRIVER_OK has been set.. */ return 0; scsi_add_host_failed: vdev->config->del_vqs(vdev); virtscsi_init_failed: scsi_host_put(shost); return err; } static void virtscsi_remove(struct virtio_device *vdev) { struct Scsi_Host *shost = virtio_scsi_host(vdev); struct virtio_scsi *vscsi = shost_priv(shost); if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) virtscsi_cancel_event_work(vscsi); scsi_remove_host(shost); unregister_hotcpu_notifier(&vscsi->nb); virtscsi_remove_vqs(vdev); scsi_host_put(shost); } #ifdef CONFIG_PM_SLEEP static int virtscsi_freeze(struct virtio_device *vdev) { virtscsi_remove_vqs(vdev); return 0; } static int virtscsi_restore(struct virtio_device *vdev) { struct Scsi_Host *sh = virtio_scsi_host(vdev); struct virtio_scsi *vscsi = shost_priv(sh); return virtscsi_init(vdev, vscsi); } #endif static struct virtio_device_id id_table[] = { { VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID }, { 0 }, }; static unsigned int features[] = { VIRTIO_SCSI_F_HOTPLUG, VIRTIO_SCSI_F_CHANGE, }; static struct virtio_driver virtio_scsi_driver = { .feature_table = features, .feature_table_size = ARRAY_SIZE(features), .driver.name = KBUILD_MODNAME, .driver.owner = THIS_MODULE, .id_table = id_table, .probe = virtscsi_probe, .scan = virtscsi_scan, #ifdef CONFIG_PM_SLEEP .freeze = virtscsi_freeze, .restore = virtscsi_restore, #endif .remove = virtscsi_remove, }; static int __init init(void) { int ret = -ENOMEM; virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0); if (!virtscsi_cmd_cache) { pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n"); goto error; } virtscsi_cmd_pool = mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ, virtscsi_cmd_cache); if (!virtscsi_cmd_pool) { pr_err("mempool_create() for virtscsi_cmd_pool failed\n"); goto error; } ret = register_virtio_driver(&virtio_scsi_driver); if (ret < 0) goto error; return 0; error: if (virtscsi_cmd_pool) { mempool_destroy(virtscsi_cmd_pool); virtscsi_cmd_pool = NULL; } if (virtscsi_cmd_cache) { kmem_cache_destroy(virtscsi_cmd_cache); virtscsi_cmd_cache = NULL; } return ret; } static void __exit fini(void) { unregister_virtio_driver(&virtio_scsi_driver); mempool_destroy(virtscsi_cmd_pool); kmem_cache_destroy(virtscsi_cmd_cache); } module_init(init); module_exit(fini); MODULE_DEVICE_TABLE(virtio, id_table); MODULE_DESCRIPTION("Virtio SCSI HBA driver"); MODULE_LICENSE("GPL");