From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- drivers/scsi/virtio_scsi.c | 1035 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1035 insertions(+) create mode 100644 drivers/scsi/virtio_scsi.c (limited to 'drivers/scsi/virtio_scsi.c') diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c new file mode 100644 index 000000000..50e87823b --- /dev/null +++ b/drivers/scsi/virtio_scsi.c @@ -0,0 +1,1035 @@ +/* + * 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 +#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_cmd_req_pi cmd_pi; + 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). + * + * tgt_seq is held to serialize reading and writing req_vq. + * + * Decrements of reqs are never concurrent with writes of req_vq: before the + * decrement reqs will be != 0; after the decrement the virtqueue completion + * routine will not use the req_vq so it can be changed by a new request. + * Thus they can happen outside the tgt_seq, provided of course we make reqs + * an atomic_t. + */ +struct virtio_scsi_target_state { + seqcount_t tgt_seq; + + /* 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; + + struct hlist_node node; + + /* Protected by event_vq lock */ + bool stop_events; + + 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; + + 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, virtio32_to_cpu(vscsi->vdev, 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(virtio32_to_cpu(vscsi->vdev, resp->sense_len) > + VIRTIO_SCSI_SENSE_SIZE); + if (sc->sense_buffer) { + memcpy(sc->sense_buffer, resp->sense, + min_t(u32, + virtio32_to_cpu(vscsi->vdev, resp->sense_len), + VIRTIO_SCSI_SENSE_SIZE)); + if (resp->sense_len) + set_driver_byte(sc, DRIVER_SENSE); + } + + sc->scsi_done(sc); +} + +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); + + if (unlikely(virtqueue_is_broken(vq))) + break; + } 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]; + + virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd); +}; + +static void virtscsi_poll_requests(struct virtio_scsi *vscsi) +{ + int i, num_vqs; + + num_vqs = vscsi->num_queues; + for (i = 0; i < num_vqs; i++) + virtscsi_vq_done(vscsi, &vscsi->req_vqs[i], + virtscsi_complete_cmd); +} + +static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf) +{ + struct virtio_scsi_cmd *cmd = buf; + + if (cmd->comp) + complete(cmd->comp); +} + +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 void virtscsi_handle_event(struct work_struct *work); + +static int virtscsi_kick_event(struct virtio_scsi *vscsi, + struct virtio_scsi_event_node *event_node) +{ + int err; + struct scatterlist sg; + unsigned long flags; + + INIT_WORK(&event_node->work, virtscsi_handle_event); + 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; + + /* Stop scheduling work before calling cancel_work_sync. */ + spin_lock_irq(&vscsi->event_vq.vq_lock); + vscsi->stop_events = true; + spin_unlock_irq(&vscsi->event_vq.vq_lock); + + 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 (virtio32_to_cpu(vscsi->vdev, 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("Unsupported 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 = virtio32_to_cpu(vscsi->vdev, event->reason) & 255; + u8 ascq = virtio32_to_cpu(vscsi->vdev, 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 & + cpu_to_virtio32(vscsi->vdev, VIRTIO_SCSI_T_EVENTS_MISSED)) { + event->event &= ~cpu_to_virtio32(vscsi->vdev, + VIRTIO_SCSI_T_EVENTS_MISSED); + scsi_scan_host(virtio_scsi_host(vscsi->vdev)); + } + + switch (virtio32_to_cpu(vscsi->vdev, 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("Unsupported 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; + + if (!vscsi->stop_events) + queue_work(system_freezable_wq, &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 + */ +static int virtscsi_add_cmd(struct virtqueue *vq, + struct virtio_scsi_cmd *cmd, + size_t req_size, size_t resp_size) +{ + struct scsi_cmnd *sc = cmd->sc; + struct scatterlist *sgs[6], 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) { + /* Place WRITE protection SGLs before Data OUT payload */ + if (scsi_prot_sg_count(sc)) + sgs[out_num++] = scsi_prot_sglist(sc); + 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) { + /* Place READ protection SGLs before Data IN payload */ + if (scsi_prot_sg_count(sc)) + sgs[out_num + in_num++] = scsi_prot_sglist(sc); + sgs[out_num + in_num++] = in->sgl; + } + + return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, GFP_ATOMIC); +} + +static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq, + struct virtio_scsi_cmd *cmd, + size_t req_size, size_t resp_size) +{ + 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); + 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 void virtio_scsi_init_hdr(struct virtio_device *vdev, + struct virtio_scsi_cmd_req *cmd, + struct scsi_cmnd *sc) +{ + cmd->lun[0] = 1; + cmd->lun[1] = sc->device->id; + cmd->lun[2] = (sc->device->lun >> 8) | 0x40; + cmd->lun[3] = sc->device->lun & 0xff; + cmd->tag = cpu_to_virtio64(vdev, (unsigned long)sc); + cmd->task_attr = VIRTIO_SCSI_S_SIMPLE; + cmd->prio = 0; + cmd->crn = 0; +} + +#ifdef CONFIG_BLK_DEV_INTEGRITY +static void virtio_scsi_init_hdr_pi(struct virtio_device *vdev, + struct virtio_scsi_cmd_req_pi *cmd_pi, + struct scsi_cmnd *sc) +{ + struct request *rq = sc->request; + struct blk_integrity *bi; + + virtio_scsi_init_hdr(vdev, (struct virtio_scsi_cmd_req *)cmd_pi, sc); + + if (!rq || !scsi_prot_sg_count(sc)) + return; + + bi = blk_get_integrity(rq->rq_disk); + + if (sc->sc_data_direction == DMA_TO_DEVICE) + cmd_pi->pi_bytesout = cpu_to_virtio32(vdev, + bio_integrity_bytes(bi, + blk_rq_sectors(rq))); + else if (sc->sc_data_direction == DMA_FROM_DEVICE) + cmd_pi->pi_bytesin = cpu_to_virtio32(vdev, + bio_integrity_bytes(bi, + blk_rq_sectors(rq))); +} +#endif + +static struct virtio_scsi_vq *virtscsi_pick_vq_mq(struct virtio_scsi *vscsi, + struct scsi_cmnd *sc) +{ + u32 tag = blk_mq_unique_tag(sc->request); + u16 hwq = blk_mq_unique_tag_to_hwq(tag); + + return &vscsi->req_vqs[hwq]; +} + +static int virtscsi_queuecommand(struct Scsi_Host *shost, + struct scsi_cmnd *sc) +{ + struct virtio_scsi *vscsi = shost_priv(shost); + struct virtio_scsi_vq *req_vq = virtscsi_pick_vq_mq(vscsi, sc); + struct virtio_scsi_cmd *cmd = scsi_cmd_priv(sc); + unsigned long flags; + int req_size; + int ret; + + 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]); + + cmd->sc = sc; + + BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE); + +#ifdef CONFIG_BLK_DEV_INTEGRITY + if (virtio_has_feature(vscsi->vdev, VIRTIO_SCSI_F_T10_PI)) { + virtio_scsi_init_hdr_pi(vscsi->vdev, &cmd->req.cmd_pi, sc); + memcpy(cmd->req.cmd_pi.cdb, sc->cmnd, sc->cmd_len); + req_size = sizeof(cmd->req.cmd_pi); + } else +#endif + { + virtio_scsi_init_hdr(vscsi->vdev, &cmd->req.cmd, sc); + memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len); + req_size = sizeof(cmd->req.cmd); + } + + ret = virtscsi_kick_cmd(req_vq, cmd, req_size, sizeof(cmd->resp.cmd)); + if (ret == -EIO) { + cmd->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET; + spin_lock_irqsave(&req_vq->vq_lock, flags); + virtscsi_complete_cmd(vscsi, cmd); + spin_unlock_irqrestore(&req_vq->vq_lock, flags); + } else if (ret != 0) { + return SCSI_MLQUEUE_HOST_BUSY; + } + return 0; +} + +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) < 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; + + /* + * The spec guarantees that all requests related to the TMF have + * been completed, but the callback might not have run yet if + * we're using independent interrupts (e.g. MSI). Poll the + * virtqueues once. + * + * In the abort case, sc->scsi_done will do nothing, because + * the block layer must have detected a timeout and as a result + * REQ_ATOM_COMPLETE has been set. + */ + virtscsi_poll_requests(vscsi); + +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->req.tmf = (struct virtio_scsi_ctrl_tmf_req){ + .type = VIRTIO_SCSI_T_TMF, + .subtype = cpu_to_virtio32(vscsi->vdev, + 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_device_alloc(struct scsi_device *sdevice) +{ + /* + * Passed through SCSI targets (e.g. with qemu's 'scsi-block') + * may have transfer limits which come from the host SCSI + * controller or something on the host side other than the + * target itself. + * + * To make this work properly, the hypervisor can adjust the + * target's VPD information to advertise these limits. But + * for that to work, the guest has to look at the VPD pages, + * which we won't do by default if it is an SPC-2 device, even + * if it does actually support it. + * + * So, set the blist to always try to read the VPD pages. + */ + sdevice->sdev_bflags = BLIST_TRY_VPD_PAGES; + + return 0; +} + + +/** + * virtscsi_change_queue_depth() - Change a virtscsi target's queue depth + * @sdev: Virtscsi target whose queue depth to change + * @qdepth: New queue depth + */ +static int virtscsi_change_queue_depth(struct scsi_device *sdev, int qdepth) +{ + struct Scsi_Host *shost = sdev->host; + int max_depth = shost->cmd_per_lun; + + return scsi_change_queue_depth(sdev, min(max_depth, qdepth)); +} + +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->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 = cpu_to_virtio64(vscsi->vdev, (unsigned long)sc), + }; + return virtscsi_tmf(vscsi, cmd); +} + +static int virtscsi_target_alloc(struct scsi_target *starget) +{ + struct Scsi_Host *sh = dev_to_shost(starget->dev.parent); + struct virtio_scsi *vscsi = shost_priv(sh); + + struct virtio_scsi_target_state *tgt = + kmalloc(sizeof(*tgt), GFP_KERNEL); + if (!tgt) + return -ENOMEM; + + seqcount_init(&tgt->tgt_seq); + tgt->req_vq = &vscsi->req_vqs[0]; + + 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 int virtscsi_map_queues(struct Scsi_Host *shost) +{ + struct virtio_scsi *vscsi = shost_priv(shost); + + return blk_mq_virtio_map_queues(&shost->tag_set, vscsi->vdev, 2); +} + +/* + * The host guarantees to respond to each command, although I/O + * latencies might be higher than on bare metal. Reset the timer + * unconditionally to give the host a chance to perform EH. + */ +static enum blk_eh_timer_return virtscsi_eh_timed_out(struct scsi_cmnd *scmnd) +{ + return BLK_EH_RESET_TIMER; +} + +static struct scsi_host_template virtscsi_host_template = { + .module = THIS_MODULE, + .name = "Virtio SCSI HBA", + .proc_name = "virtio_scsi", + .this_id = -1, + .cmd_size = sizeof(struct virtio_scsi_cmd), + .queuecommand = virtscsi_queuecommand, + .change_queue_depth = virtscsi_change_queue_depth, + .eh_abort_handler = virtscsi_abort, + .eh_device_reset_handler = virtscsi_device_reset, + .eh_timed_out = virtscsi_eh_timed_out, + .slave_alloc = virtscsi_device_alloc, + + .dma_boundary = UINT_MAX, + .use_clustering = ENABLE_CLUSTERING, + .target_alloc = virtscsi_target_alloc, + .target_destroy = virtscsi_target_destroy, + .map_queues = virtscsi_map_queues, + .track_queue_depth = 1, + .force_blk_mq = 1, +}; + +#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_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_remove_vqs(struct virtio_device *vdev) +{ + /* 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; + struct irq_affinity desc = { .pre_vectors = 2 }; + + num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE; + vqs = kmalloc_array(num_vqs, sizeof(struct virtqueue *), GFP_KERNEL); + callbacks = kmalloc_array(num_vqs, sizeof(vq_callback_t *), + GFP_KERNEL); + names = kmalloc_array(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 = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); + 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_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE); + virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE); + + 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; + + if (!vdev->config->get) { + dev_err(&vdev->dev, "%s failure: config access disabled\n", + __func__); + return -EINVAL; + } + + /* 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; + + shost = scsi_host_alloc(&virtscsi_host_template, + 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; + + shost->can_queue = virtqueue_get_vring_size(vscsi->req_vqs[0].vq); + + 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; + shost->nr_hw_queues = num_queues; + +#ifdef CONFIG_BLK_DEV_INTEGRITY + if (virtio_has_feature(vdev, VIRTIO_SCSI_F_T10_PI)) { + int host_prot; + + host_prot = SHOST_DIF_TYPE1_PROTECTION | SHOST_DIF_TYPE2_PROTECTION | + SHOST_DIF_TYPE3_PROTECTION | SHOST_DIX_TYPE1_PROTECTION | + SHOST_DIX_TYPE2_PROTECTION | SHOST_DIX_TYPE3_PROTECTION; + + scsi_host_set_prot(shost, host_prot); + scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); + } +#endif + + err = scsi_add_host(shost, &vdev->dev); + if (err) + goto scsi_add_host_failed; + + virtio_device_ready(vdev); + + if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) + virtscsi_kick_event_all(vscsi); + + scsi_scan_host(shost); + 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); + 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); + int err; + + err = virtscsi_init(vdev, vscsi); + if (err) + return err; + + virtio_device_ready(vdev); + + if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) + virtscsi_kick_event_all(vscsi); + + return err; +} +#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, +#ifdef CONFIG_BLK_DEV_INTEGRITY + VIRTIO_SCSI_F_T10_PI, +#endif +}; + +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, +#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"); -- cgit v1.2.3