| /* |
| * 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 <linux/platform_device.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 device *dev) |
| { |
| put_device(&class_to_shost(dev)->shost_gendev); |
| } |
| |
| static struct class shost_class = { |
| .name = "scsi_host", |
| .dev_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, |
| shost_printk(KERN_ERR, shost, |
| "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; |
| 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); |
| mutex_unlock(&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); |
| device_unregister(&shost->shost_dev); |
| 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 fail; |
| } |
| |
| error = scsi_setup_command_freelist(shost); |
| if (error) |
| goto fail; |
| |
| 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 = device_add(&shost->shost_dev); |
| if (error) |
| goto out_del_gendev; |
| |
| get_device(&shost->shost_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, KOBJ_NAME_LEN, "scsi_wq_%d", |
| shost->host_no); |
| shost->work_q = create_singlethread_workqueue( |
| shost->work_q_name); |
| if (!shost->work_q) { |
| error = -EINVAL; |
| 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_dev: |
| device_del(&shost->shost_dev); |
| out_del_gendev: |
| device_del(&shost->shost_gendev); |
| out: |
| scsi_destroy_command_freelist(shost); |
| fail: |
| 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); |
| if (shost->uspace_req_q) { |
| kfree(shost->uspace_req_q->queuedata); |
| scsi_free_queue(shost->uspace_req_q); |
| } |
| |
| scsi_destroy_command_freelist(shost); |
| if (shost->bqt) |
| blk_free_tags(shost->bqt); |
| |
| kfree(shost->shost_data); |
| |
| if (parent) |
| 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(struct scsi_host_template *sht, int privsize) |
| { |
| struct Scsi_Host *shost; |
| gfp_t gfp_mask = GFP_KERNEL; |
| int rval; |
| |
| if (sht->unchecked_isa_dma && privsize) |
| gfp_mask |= __GFP_DMA; |
| |
| shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); |
| 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_cmd_q); |
| INIT_LIST_HEAD(&shost->starved_list); |
| init_waitqueue_head(&shost->host_wait); |
| |
| mutex_init(&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_tag = sht->ordered_tag; |
| |
| 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; |
| |
| /* |
| * assume a 4GB boundary, if not set |
| */ |
| if (sht->dma_boundary) |
| shost->dma_boundary = sht->dma_boundary; |
| else |
| shost->dma_boundary = 0xffffffff; |
| |
| device_initialize(&shost->shost_gendev); |
| snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", |
| shost->host_no); |
| #ifndef CONFIG_SYSFS_DEPRECATED |
| shost->shost_gendev.bus = &scsi_bus_type; |
| #endif |
| shost->shost_gendev.type = &scsi_host_type; |
| |
| device_initialize(&shost->shost_dev); |
| shost->shost_dev.parent = &shost->shost_gendev; |
| shost->shost_dev.class = &shost_class; |
| snprintf(shost->shost_dev.bus_id, BUS_ID_SIZE, "host%d", |
| shost->host_no); |
| shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; |
| |
| 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_kfree; |
| } |
| |
| scsi_proc_hostdir_add(shost->hostt); |
| return 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); |
| |
| static int __scsi_host_match(struct device *dev, void *data) |
| { |
| struct Scsi_Host *p; |
| unsigned short *hostnum = (unsigned short *)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 = ERR_PTR(-ENXIO); |
| |
| 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); |
| |
| /** |
| * 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->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)) { |
| 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); |