/* * 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 * * <drew@colorado.edu> * * 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 <tmm@image.dk> * * Restructured scsi_host lists and associated functions. * September 04, 2002 Mike Anderson (andmike@us.ibm.com) */ #include <linux/module.h> #include <linux/blkdev.h> #include <linux/kernel.h> #include <linux/kthread.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/init.h> #include <linux/completion.h> #include <linux/transport_class.h> #include <scsi/scsi_device.h> #include <scsi/scsi_host.h> #include <scsi/scsi_transport.h> #include "scsi_priv.h" #include "scsi_logging.h" static int scsi_host_next_hn; /* host_no for next new host */ static void scsi_host_cls_release(struct class_device *class_dev) { put_device(&class_to_shost(class_dev)->shost_gendev); } static struct class shost_class = { .name = "scsi_host", .release = scsi_host_cls_release, }; /** * 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, dev_printk(KERN_ERR, &shost->shost_gendev, "Illegal host state transition" "%s->%s\n", scsi_host_state_name(oldstate), scsi_host_state_name(state))); return -EINVAL; } EXPORT_SYMBOL(scsi_host_set_state); /** * 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; down(&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); up(&shost->scan_mutex); return; } spin_unlock_irqrestore(shost->host_lock, flags); up(&shost->scan_mutex); scsi_forget_host(shost); scsi_proc_host_rm(shost); 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); class_device_unregister(&shost->shost_classdev); device_del(&shost->shost_gendev); scsi_proc_hostdir_rm(shost->hostt); } EXPORT_SYMBOL(scsi_remove_host); /** * scsi_add_host - add a scsi host * @shost: scsi host pointer to add * @dev: a struct device of type scsi class * * Return value: * 0 on success / != 0 for error **/ int scsi_add_host(struct Scsi_Host *shost, struct device *dev) { struct scsi_host_template *sht = shost->hostt; int error = -EINVAL; printk(KERN_INFO "scsi%d : %s\n", shost->host_no, sht->info ? sht->info(shost) : sht->name); if (!shost->can_queue) { printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", sht->name); goto out; } if (!shost->shost_gendev.parent) shost->shost_gendev.parent = dev ? dev : &platform_bus; error = device_add(&shost->shost_gendev); if (error) goto out; scsi_host_set_state(shost, SHOST_RUNNING); get_device(shost->shost_gendev.parent); error = class_device_add(&shost->shost_classdev); if (error) goto out_del_gendev; get_device(&shost->shost_gendev); if (shost->transportt->host_size && (shost->shost_data = kmalloc(shost->transportt->host_size, GFP_KERNEL)) == NULL) goto out_del_classdev; if (shost->transportt->create_work_queue) { snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d", shost->host_no); shost->work_q = create_singlethread_workqueue( shost->work_q_name); if (!shost->work_q) goto out_free_shost_data; } error = scsi_sysfs_add_host(shost); if (error) goto out_destroy_host; scsi_proc_host_add(shost); return error; out_destroy_host: if (shost->work_q) destroy_workqueue(shost->work_q); out_free_shost_data: kfree(shost->shost_data); out_del_classdev: class_device_del(&shost->shost_classdev); out_del_gendev: device_del(&shost->shost_gendev); out: return error; } EXPORT_SYMBOL(scsi_add_host); static void scsi_host_dev_release(struct device *dev) { struct Scsi_Host *shost = dev_to_shost(dev); struct device *parent = dev->parent; if (shost->ehandler) kthread_stop(shost->ehandler); if (shost->work_q) destroy_workqueue(shost->work_q); scsi_destroy_command_freelist(shost); kfree(shost->shost_data); if (parent) put_device(parent); kfree(shost); } /** * 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(struct scsi_host_template *sht, int privsize) { struct Scsi_Host *shost; int gfp_mask = GFP_KERNEL, rval; if (sht->unchecked_isa_dma && privsize) gfp_mask |= __GFP_DMA; /* Check to see if this host has any error handling facilities */ if (!sht->eh_strategy_handler && !sht->eh_abort_handler && !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler && !sht->eh_host_reset_handler) { printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n" "ERROR: This is not a safe way to run your " "SCSI host\n" "ERROR: The error handling must be added to " "this driver\n", sht->proc_name); dump_stack(); } shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); if (!shost) return NULL; memset(shost, 0, sizeof(struct Scsi_Host) + privsize); spin_lock_init(&shost->default_lock); scsi_assign_lock(shost, &shost->default_lock); shost->shost_state = SHOST_CREATED; INIT_LIST_HEAD(&shost->__devices); INIT_LIST_HEAD(&shost->__targets); INIT_LIST_HEAD(&shost->eh_cmd_q); INIT_LIST_HEAD(&shost->starved_list); init_waitqueue_head(&shost->host_wait); init_MUTEX(&shost->scan_mutex); shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */ 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->cmd_per_lun = sht->cmd_per_lun; shost->unchecked_isa_dma = sht->unchecked_isa_dma; shost->use_clustering = sht->use_clustering; shost->ordered_flush = sht->ordered_flush; shost->ordered_tag = sht->ordered_tag; /* * hosts/devices that do queueing must support ordered tags */ if (shost->can_queue > 1 && shost->ordered_flush) { printk(KERN_ERR "scsi: ordered flushes don't support queueing\n"); shost->ordered_flush = 0; } 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; /* * assume a 4GB boundary, if not set */ if (sht->dma_boundary) shost->dma_boundary = sht->dma_boundary; else shost->dma_boundary = 0xffffffff; rval = scsi_setup_command_freelist(shost); if (rval) goto fail_kfree; device_initialize(&shost->shost_gendev); snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", shost->host_no); shost->shost_gendev.release = scsi_host_dev_release; class_device_initialize(&shost->shost_classdev); shost->shost_classdev.dev = &shost->shost_gendev; shost->shost_classdev.class = &shost_class; snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d", shost->host_no); shost->ehandler = kthread_run(scsi_error_handler, shost, "scsi_eh_%d", shost->host_no); if (IS_ERR(shost->ehandler)) { rval = PTR_ERR(shost->ehandler); goto fail_destroy_freelist; } scsi_proc_hostdir_add(shost->hostt); return shost; fail_destroy_freelist: scsi_destroy_command_freelist(shost); fail_kfree: kfree(shost); return NULL; } EXPORT_SYMBOL(scsi_host_alloc); struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) { struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); if (!sht->detect) { printk(KERN_WARNING "scsi_register() called on new-style " "template for driver %s\n", sht->name); dump_stack(); } if (shost) list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); return shost; } EXPORT_SYMBOL(scsi_register); void scsi_unregister(struct Scsi_Host *shost) { list_del(&shost->sht_legacy_list); scsi_host_put(shost); } EXPORT_SYMBOL(scsi_unregister); /** * 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. **/ struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) { struct class *class = &shost_class; struct class_device *cdev; struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p; down_read(&class->subsys.rwsem); list_for_each_entry(cdev, &class->children, node) { p = class_to_shost(cdev); if (p->host_no == hostnum) { shost = scsi_host_get(p); break; } } up_read(&class->subsys.rwsem); 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); /** * 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); } int scsi_is_host_device(const struct device *dev) { return dev->release == scsi_host_dev_release; } 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: * 0 on success / != 0 for error **/ int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) { if (unlikely(!shost->work_q)) { printk(KERN_ERR "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) { printk(KERN_ERR "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);