// SPDX-License-Identifier: GPL-2.0-only /* * hosts.c Copyright (C) 1992 Drew Eckhardt * Copyright (C) 1993, 1994, 1995 Eric Youngdale * Copyright (C) 2002-2003 Christoph Hellwig * * mid to lowlevel SCSI driver interface * Initial versions: Drew Eckhardt * Subsequent revisions: Eric Youngdale * * * * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli * Added QLOGIC QLA1280 SCSI controller kernel host support. * August 4, 1999 Fred Lewis, Intel DuPont * * Updated to reflect the new initialization scheme for the higher * level of scsi drivers (sd/sr/st) * September 17, 2000 Torben Mathiasen * * Restructured scsi_host lists and associated functions. * September 04, 2002 Mike Anderson (andmike@us.ibm.com) */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "scsi_priv.h" #include "scsi_logging.h" static int shost_eh_deadline = -1; module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(eh_deadline, "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); static DEFINE_IDA(host_index_ida); static void scsi_host_cls_release(struct device *dev) { put_device(&class_to_shost(dev)->shost_gendev); } static struct class shost_class = { .name = "scsi_host", .dev_release = scsi_host_cls_release, .dev_groups = scsi_shost_groups, }; /** * scsi_host_set_state - Take the given host through the host state model. * @shost: scsi host to change the state of. * @state: state to change to. * * Returns zero if unsuccessful or an error if the requested * transition is illegal. **/ int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) { enum scsi_host_state oldstate = shost->shost_state; if (state == oldstate) return 0; switch (state) { case SHOST_CREATED: /* There are no legal states that come back to * created. This is the manually initialised start * state */ goto illegal; case SHOST_RUNNING: switch (oldstate) { case SHOST_CREATED: case SHOST_RECOVERY: break; default: goto illegal; } break; case SHOST_RECOVERY: switch (oldstate) { case SHOST_RUNNING: break; default: goto illegal; } break; case SHOST_CANCEL: switch (oldstate) { case SHOST_CREATED: case SHOST_RUNNING: case SHOST_CANCEL_RECOVERY: break; default: goto illegal; } break; case SHOST_DEL: switch (oldstate) { case SHOST_CANCEL: case SHOST_DEL_RECOVERY: break; default: goto illegal; } break; case SHOST_CANCEL_RECOVERY: switch (oldstate) { case SHOST_CANCEL: case SHOST_RECOVERY: break; default: goto illegal; } break; case SHOST_DEL_RECOVERY: switch (oldstate) { case SHOST_CANCEL_RECOVERY: break; default: goto illegal; } break; } shost->shost_state = state; return 0; illegal: SCSI_LOG_ERROR_RECOVERY(1, shost_printk(KERN_ERR, shost, "Illegal host state transition" "%s->%s\n", scsi_host_state_name(oldstate), scsi_host_state_name(state))); return -EINVAL; } /** * scsi_remove_host - remove a scsi host * @shost: a pointer to a scsi host to remove **/ void scsi_remove_host(struct Scsi_Host *shost) { unsigned long flags; mutex_lock(&shost->scan_mutex); spin_lock_irqsave(shost->host_lock, flags); if (scsi_host_set_state(shost, SHOST_CANCEL)) if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { spin_unlock_irqrestore(shost->host_lock, flags); mutex_unlock(&shost->scan_mutex); return; } spin_unlock_irqrestore(shost->host_lock, flags); scsi_autopm_get_host(shost); flush_workqueue(shost->tmf_work_q); scsi_forget_host(shost); mutex_unlock(&shost->scan_mutex); scsi_proc_host_rm(shost); scsi_proc_hostdir_rm(shost->hostt); /* * New SCSI devices cannot be attached anymore because of the SCSI host * state so drop the tag set refcnt. Wait until the tag set refcnt drops * to zero because .exit_cmd_priv implementations may need the host * pointer. */ kref_put(&shost->tagset_refcnt, scsi_mq_free_tags); wait_for_completion(&shost->tagset_freed); spin_lock_irqsave(shost->host_lock, flags); if (scsi_host_set_state(shost, SHOST_DEL)) BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); spin_unlock_irqrestore(shost->host_lock, flags); transport_unregister_device(&shost->shost_gendev); device_unregister(&shost->shost_dev); device_del(&shost->shost_gendev); } EXPORT_SYMBOL(scsi_remove_host); /** * scsi_add_host_with_dma - add a scsi host with dma device * @shost: scsi host pointer to add * @dev: a struct device of type scsi class * @dma_dev: dma device for the host * * Note: You rarely need to worry about this unless you're in a * virtualised host environments, so use the simpler scsi_add_host() * function instead. * * Return value: * 0 on success / != 0 for error **/ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, struct device *dma_dev) { const struct scsi_host_template *sht = shost->hostt; int error = -EINVAL; shost_printk(KERN_INFO, shost, "%s\n", sht->info ? sht->info(shost) : sht->name); if (!shost->can_queue) { shost_printk(KERN_ERR, shost, "can_queue = 0 no longer supported\n"); goto fail; } /* Use min_t(int, ...) in case shost->can_queue exceeds SHRT_MAX */ shost->cmd_per_lun = min_t(int, shost->cmd_per_lun, shost->can_queue); error = scsi_init_sense_cache(shost); if (error) goto fail; if (!shost->shost_gendev.parent) shost->shost_gendev.parent = dev ? dev : &platform_bus; if (!dma_dev) dma_dev = shost->shost_gendev.parent; shost->dma_dev = dma_dev; if (dma_dev->dma_mask) { shost->max_sectors = min_t(unsigned int, shost->max_sectors, dma_max_mapping_size(dma_dev) >> SECTOR_SHIFT); } error = scsi_mq_setup_tags(shost); if (error) goto fail; kref_init(&shost->tagset_refcnt); init_completion(&shost->tagset_freed); /* * Increase usage count temporarily here so that calling * scsi_autopm_put_host() will trigger runtime idle if there is * nothing else preventing suspending the device. */ pm_runtime_get_noresume(&shost->shost_gendev); pm_runtime_set_active(&shost->shost_gendev); pm_runtime_enable(&shost->shost_gendev); device_enable_async_suspend(&shost->shost_gendev); error = device_add(&shost->shost_gendev); if (error) goto out_disable_runtime_pm; scsi_host_set_state(shost, SHOST_RUNNING); get_device(shost->shost_gendev.parent); device_enable_async_suspend(&shost->shost_dev); get_device(&shost->shost_gendev); error = device_add(&shost->shost_dev); if (error) goto out_del_gendev; if (shost->transportt->host_size) { shost->shost_data = kzalloc(shost->transportt->host_size, GFP_KERNEL); if (shost->shost_data == NULL) { error = -ENOMEM; goto out_del_dev; } } if (shost->transportt->create_work_queue) { snprintf(shost->work_q_name, sizeof(shost->work_q_name), "scsi_wq_%d", shost->host_no); shost->work_q = alloc_workqueue("%s", WQ_SYSFS | __WQ_LEGACY | WQ_MEM_RECLAIM | WQ_UNBOUND, 1, shost->work_q_name); if (!shost->work_q) { error = -EINVAL; goto out_del_dev; } } error = scsi_sysfs_add_host(shost); if (error) goto out_del_dev; scsi_proc_host_add(shost); scsi_autopm_put_host(shost); return error; /* * Any host allocation in this function will be freed in * scsi_host_dev_release(). */ out_del_dev: device_del(&shost->shost_dev); out_del_gendev: /* * Host state is SHOST_RUNNING so we have to explicitly release * ->shost_dev. */ put_device(&shost->shost_dev); device_del(&shost->shost_gendev); out_disable_runtime_pm: device_disable_async_suspend(&shost->shost_gendev); pm_runtime_disable(&shost->shost_gendev); pm_runtime_set_suspended(&shost->shost_gendev); pm_runtime_put_noidle(&shost->shost_gendev); kref_put(&shost->tagset_refcnt, scsi_mq_free_tags); fail: return error; } EXPORT_SYMBOL(scsi_add_host_with_dma); static void scsi_host_dev_release(struct device *dev) { struct Scsi_Host *shost = dev_to_shost(dev); struct device *parent = dev->parent; /* In case scsi_remove_host() has not been called. */ scsi_proc_hostdir_rm(shost->hostt); /* Wait for functions invoked through call_rcu(&scmd->rcu, ...) */ rcu_barrier(); if (shost->tmf_work_q) destroy_workqueue(shost->tmf_work_q); if (shost->ehandler) kthread_stop(shost->ehandler); if (shost->work_q) destroy_workqueue(shost->work_q); if (shost->shost_state == SHOST_CREATED) { /* * Free the shost_dev device name here if scsi_host_alloc() * and scsi_host_put() have been called but neither * scsi_host_add() nor scsi_remove_host() has been called. * This avoids that the memory allocated for the shost_dev * name is leaked. */ kfree(dev_name(&shost->shost_dev)); } kfree(shost->shost_data); ida_free(&host_index_ida, shost->host_no); if (shost->shost_state != SHOST_CREATED) put_device(parent); kfree(shost); } static struct device_type scsi_host_type = { .name = "scsi_host", .release = scsi_host_dev_release, }; /** * scsi_host_alloc - register a scsi host adapter instance. * @sht: pointer to scsi host template * @privsize: extra bytes to allocate for driver * * Note: * Allocate a new Scsi_Host and perform basic initialization. * The host is not published to the scsi midlayer until scsi_add_host * is called. * * Return value: * Pointer to a new Scsi_Host **/ struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *sht, int privsize) { struct Scsi_Host *shost; int index; shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL); if (!shost) return NULL; shost->host_lock = &shost->default_lock; spin_lock_init(shost->host_lock); shost->shost_state = SHOST_CREATED; INIT_LIST_HEAD(&shost->__devices); INIT_LIST_HEAD(&shost->__targets); INIT_LIST_HEAD(&shost->eh_abort_list); INIT_LIST_HEAD(&shost->eh_cmd_q); INIT_LIST_HEAD(&shost->starved_list); init_waitqueue_head(&shost->host_wait); mutex_init(&shost->scan_mutex); index = ida_alloc(&host_index_ida, GFP_KERNEL); if (index < 0) { kfree(shost); return NULL; } shost->host_no = index; shost->dma_channel = 0xff; /* These three are default values which can be overridden */ shost->max_channel = 0; shost->max_id = 8; shost->max_lun = 8; /* Give each shost a default transportt */ shost->transportt = &blank_transport_template; /* * All drivers right now should be able to handle 12 byte * commands. Every so often there are requests for 16 byte * commands, but individual low-level drivers need to certify that * they actually do something sensible with such commands. */ shost->max_cmd_len = 12; shost->hostt = sht; shost->this_id = sht->this_id; shost->can_queue = sht->can_queue; shost->sg_tablesize = sht->sg_tablesize; shost->sg_prot_tablesize = sht->sg_prot_tablesize; shost->cmd_per_lun = sht->cmd_per_lun; shost->no_write_same = sht->no_write_same; shost->host_tagset = sht->host_tagset; if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) shost->eh_deadline = -1; else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { shost_printk(KERN_WARNING, shost, "eh_deadline %u too large, setting to %u\n", shost_eh_deadline, INT_MAX / HZ); shost->eh_deadline = INT_MAX; } else shost->eh_deadline = shost_eh_deadline * HZ; if (sht->supported_mode == MODE_UNKNOWN) /* means we didn't set it ... default to INITIATOR */ shost->active_mode = MODE_INITIATOR; else shost->active_mode = sht->supported_mode; if (sht->max_host_blocked) shost->max_host_blocked = sht->max_host_blocked; else shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; /* * If the driver imposes no hard sector transfer limit, start at * machine infinity initially. */ if (sht->max_sectors) shost->max_sectors = sht->max_sectors; else shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; if (sht->max_segment_size) shost->max_segment_size = sht->max_segment_size; else shost->max_segment_size = BLK_MAX_SEGMENT_SIZE; /* * assume a 4GB boundary, if not set */ if (sht->dma_boundary) shost->dma_boundary = sht->dma_boundary; else shost->dma_boundary = 0xffffffff; if (sht->virt_boundary_mask) shost->virt_boundary_mask = sht->virt_boundary_mask; device_initialize(&shost->shost_gendev); dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); shost->shost_gendev.bus = &scsi_bus_type; shost->shost_gendev.type = &scsi_host_type; scsi_enable_async_suspend(&shost->shost_gendev); device_initialize(&shost->shost_dev); shost->shost_dev.parent = &shost->shost_gendev; shost->shost_dev.class = &shost_class; dev_set_name(&shost->shost_dev, "host%d", shost->host_no); shost->shost_dev.groups = sht->shost_groups; shost->ehandler = kthread_run(scsi_error_handler, shost, "scsi_eh_%d", shost->host_no); if (IS_ERR(shost->ehandler)) { shost_printk(KERN_WARNING, shost, "error handler thread failed to spawn, error = %ld\n", PTR_ERR(shost->ehandler)); shost->ehandler = NULL; goto fail; } shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 1, shost->host_no); if (!shost->tmf_work_q) { shost_printk(KERN_WARNING, shost, "failed to create tmf workq\n"); goto fail; } if (scsi_proc_hostdir_add(shost->hostt) < 0) goto fail; return shost; fail: /* * Host state is still SHOST_CREATED and that is enough to release * ->shost_gendev. scsi_host_dev_release() will free * dev_name(&shost->shost_dev). */ put_device(&shost->shost_gendev); return NULL; } EXPORT_SYMBOL(scsi_host_alloc); static int __scsi_host_match(struct device *dev, const void *data) { struct Scsi_Host *p; const unsigned short *hostnum = data; p = class_to_shost(dev); return p->host_no == *hostnum; } /** * scsi_host_lookup - get a reference to a Scsi_Host by host no * @hostnum: host number to locate * * Return value: * A pointer to located Scsi_Host or NULL. * * The caller must do a scsi_host_put() to drop the reference * that scsi_host_get() took. The put_device() below dropped * the reference from class_find_device(). **/ struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) { struct device *cdev; struct Scsi_Host *shost = NULL; cdev = class_find_device(&shost_class, NULL, &hostnum, __scsi_host_match); if (cdev) { shost = scsi_host_get(class_to_shost(cdev)); put_device(cdev); } return shost; } EXPORT_SYMBOL(scsi_host_lookup); /** * scsi_host_get - inc a Scsi_Host ref count * @shost: Pointer to Scsi_Host to inc. **/ struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) { if ((shost->shost_state == SHOST_DEL) || !get_device(&shost->shost_gendev)) return NULL; return shost; } EXPORT_SYMBOL(scsi_host_get); static bool scsi_host_check_in_flight(struct request *rq, void *data) { int *count = data; struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq); if (test_bit(SCMD_STATE_INFLIGHT, &cmd->state)) (*count)++; return true; } /** * scsi_host_busy - Return the host busy counter * @shost: Pointer to Scsi_Host to inc. **/ int scsi_host_busy(struct Scsi_Host *shost) { int cnt = 0; blk_mq_tagset_busy_iter(&shost->tag_set, scsi_host_check_in_flight, &cnt); return cnt; } EXPORT_SYMBOL(scsi_host_busy); /** * scsi_host_put - dec a Scsi_Host ref count * @shost: Pointer to Scsi_Host to dec. **/ void scsi_host_put(struct Scsi_Host *shost) { put_device(&shost->shost_gendev); } EXPORT_SYMBOL(scsi_host_put); int scsi_init_hosts(void) { return class_register(&shost_class); } void scsi_exit_hosts(void) { class_unregister(&shost_class); ida_destroy(&host_index_ida); } int scsi_is_host_device(const struct device *dev) { return dev->type == &scsi_host_type; } EXPORT_SYMBOL(scsi_is_host_device); /** * scsi_queue_work - Queue work to the Scsi_Host workqueue. * @shost: Pointer to Scsi_Host. * @work: Work to queue for execution. * * Return value: * 1 - work queued for execution * 0 - work is already queued * -EINVAL - work queue doesn't exist **/ int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) { if (unlikely(!shost->work_q)) { shost_printk(KERN_ERR, shost, "ERROR: Scsi host '%s' attempted to queue scsi-work, " "when no workqueue created.\n", shost->hostt->name); dump_stack(); return -EINVAL; } return queue_work(shost->work_q, work); } EXPORT_SYMBOL_GPL(scsi_queue_work); /** * scsi_flush_work - Flush a Scsi_Host's workqueue. * @shost: Pointer to Scsi_Host. **/ void scsi_flush_work(struct Scsi_Host *shost) { if (!shost->work_q) { shost_printk(KERN_ERR, shost, "ERROR: Scsi host '%s' attempted to flush scsi-work, " "when no workqueue created.\n", shost->hostt->name); dump_stack(); return; } flush_workqueue(shost->work_q); } EXPORT_SYMBOL_GPL(scsi_flush_work); static bool complete_all_cmds_iter(struct request *rq, void *data) { struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq); enum scsi_host_status status = *(enum scsi_host_status *)data; scsi_dma_unmap(scmd); scmd->result = 0; set_host_byte(scmd, status); scsi_done(scmd); return true; } /** * scsi_host_complete_all_commands - Terminate all running commands * @shost: Scsi Host on which commands should be terminated * @status: Status to be set for the terminated commands * * There is no protection against modification of the number * of outstanding commands. It is the responsibility of the * caller to ensure that concurrent I/O submission and/or * completion is stopped when calling this function. */ void scsi_host_complete_all_commands(struct Scsi_Host *shost, enum scsi_host_status status) { blk_mq_tagset_busy_iter(&shost->tag_set, complete_all_cmds_iter, &status); } EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands); struct scsi_host_busy_iter_data { bool (*fn)(struct scsi_cmnd *, void *); void *priv; }; static bool __scsi_host_busy_iter_fn(struct request *req, void *priv) { struct scsi_host_busy_iter_data *iter_data = priv; struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req); return iter_data->fn(sc, iter_data->priv); } /** * scsi_host_busy_iter - Iterate over all busy commands * @shost: Pointer to Scsi_Host. * @fn: Function to call on each busy command * @priv: Data pointer passed to @fn * * If locking against concurrent command completions is required * ithas to be provided by the caller **/ void scsi_host_busy_iter(struct Scsi_Host *shost, bool (*fn)(struct scsi_cmnd *, void *), void *priv) { struct scsi_host_busy_iter_data iter_data = { .fn = fn, .priv = priv, }; blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn, &iter_data); } EXPORT_SYMBOL_GPL(scsi_host_busy_iter);