2 * hosts.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995 Eric Youngdale
4 * Copyright (C) 2002-2003 Christoph Hellwig
6 * mid to lowlevel SCSI driver interface
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
12 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
13 * Added QLOGIC QLA1280 SCSI controller kernel host support.
14 * August 4, 1999 Fred Lewis, Intel DuPont
16 * Updated to reflect the new initialization scheme for the higher
17 * level of scsi drivers (sd/sr/st)
18 * September 17, 2000 Torben Mathiasen <tmm@image.dk>
20 * Restructured scsi_host lists and associated functions.
21 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
24 #include <linux/module.h>
25 #include <linux/blkdev.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
28 #include <linux/kthread.h>
29 #include <linux/string.h>
31 #include <linux/init.h>
32 #include <linux/completion.h>
33 #include <linux/transport_class.h>
34 #include <linux/platform_device.h>
35 #include <linux/pm_runtime.h>
37 #include <scsi/scsi_device.h>
38 #include <scsi/scsi_host.h>
39 #include <scsi/scsi_transport.h>
41 #include "scsi_priv.h"
42 #include "scsi_logging.h"
45 static atomic_t scsi_host_next_hn; /* host_no for next new host */
48 static void scsi_host_cls_release(struct device *dev)
50 put_device(&class_to_shost(dev)->shost_gendev);
53 static struct class shost_class = {
55 .dev_release = scsi_host_cls_release,
59 * scsi_host_set_state - Take the given host through the host state model.
60 * @shost: scsi host to change the state of.
61 * @state: state to change to.
63 * Returns zero if unsuccessful or an error if the requested
64 * transition is illegal.
66 int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
68 enum scsi_host_state oldstate = shost->shost_state;
70 if (state == oldstate)
75 /* There are no legal states that come back to
76 * created. This is the manually initialised start
103 case SHOST_CANCEL_RECOVERY:
113 case SHOST_DEL_RECOVERY:
120 case SHOST_CANCEL_RECOVERY:
130 case SHOST_DEL_RECOVERY:
132 case SHOST_CANCEL_RECOVERY:
139 shost->shost_state = state;
143 SCSI_LOG_ERROR_RECOVERY(1,
144 shost_printk(KERN_ERR, shost,
145 "Illegal host state transition"
147 scsi_host_state_name(oldstate),
148 scsi_host_state_name(state)));
151 EXPORT_SYMBOL(scsi_host_set_state);
154 * scsi_remove_host - remove a scsi host
155 * @shost: a pointer to a scsi host to remove
157 void scsi_remove_host(struct Scsi_Host *shost)
161 mutex_lock(&shost->scan_mutex);
162 spin_lock_irqsave(shost->host_lock, flags);
163 if (scsi_host_set_state(shost, SHOST_CANCEL))
164 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
165 spin_unlock_irqrestore(shost->host_lock, flags);
166 mutex_unlock(&shost->scan_mutex);
169 spin_unlock_irqrestore(shost->host_lock, flags);
171 scsi_autopm_get_host(shost);
172 scsi_forget_host(shost);
173 mutex_unlock(&shost->scan_mutex);
174 scsi_proc_host_rm(shost);
176 spin_lock_irqsave(shost->host_lock, flags);
177 if (scsi_host_set_state(shost, SHOST_DEL))
178 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
179 spin_unlock_irqrestore(shost->host_lock, flags);
181 transport_unregister_device(&shost->shost_gendev);
182 device_unregister(&shost->shost_dev);
183 device_del(&shost->shost_gendev);
185 EXPORT_SYMBOL(scsi_remove_host);
188 * scsi_add_host_with_dma - add a scsi host with dma device
189 * @shost: scsi host pointer to add
190 * @dev: a struct device of type scsi class
191 * @dma_dev: dma device for the host
193 * Note: You rarely need to worry about this unless you're in a
194 * virtualised host environments, so use the simpler scsi_add_host()
198 * 0 on success / != 0 for error
200 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
201 struct device *dma_dev)
203 struct scsi_host_template *sht = shost->hostt;
206 printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
207 sht->info ? sht->info(shost) : sht->name);
209 if (!shost->can_queue) {
210 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
215 error = scsi_setup_command_freelist(shost);
219 if (!shost->shost_gendev.parent)
220 shost->shost_gendev.parent = dev ? dev : &platform_bus;
221 shost->dma_dev = dma_dev;
223 error = device_add(&shost->shost_gendev);
227 pm_runtime_set_active(&shost->shost_gendev);
228 pm_runtime_enable(&shost->shost_gendev);
229 device_enable_async_suspend(&shost->shost_gendev);
231 scsi_host_set_state(shost, SHOST_RUNNING);
232 get_device(shost->shost_gendev.parent);
234 device_enable_async_suspend(&shost->shost_dev);
236 error = device_add(&shost->shost_dev);
240 get_device(&shost->shost_gendev);
242 if (shost->transportt->host_size) {
243 shost->shost_data = kzalloc(shost->transportt->host_size,
245 if (shost->shost_data == NULL) {
251 if (shost->transportt->create_work_queue) {
252 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
253 "scsi_wq_%d", shost->host_no);
254 shost->work_q = create_singlethread_workqueue(
256 if (!shost->work_q) {
258 goto out_free_shost_data;
262 error = scsi_sysfs_add_host(shost);
264 goto out_destroy_host;
266 scsi_proc_host_add(shost);
271 destroy_workqueue(shost->work_q);
273 kfree(shost->shost_data);
275 device_del(&shost->shost_dev);
277 device_del(&shost->shost_gendev);
279 scsi_destroy_command_freelist(shost);
283 EXPORT_SYMBOL(scsi_add_host_with_dma);
285 static void scsi_host_dev_release(struct device *dev)
287 struct Scsi_Host *shost = dev_to_shost(dev);
288 struct device *parent = dev->parent;
289 struct request_queue *q;
291 scsi_proc_hostdir_rm(shost->hostt);
294 kthread_stop(shost->ehandler);
296 destroy_workqueue(shost->work_q);
297 q = shost->uspace_req_q;
304 scsi_destroy_command_freelist(shost);
306 blk_free_tags(shost->bqt);
308 kfree(shost->shost_data);
315 static struct device_type scsi_host_type = {
317 .release = scsi_host_dev_release,
321 * scsi_host_alloc - register a scsi host adapter instance.
322 * @sht: pointer to scsi host template
323 * @privsize: extra bytes to allocate for driver
326 * Allocate a new Scsi_Host and perform basic initialization.
327 * The host is not published to the scsi midlayer until scsi_add_host
331 * Pointer to a new Scsi_Host
333 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
335 struct Scsi_Host *shost;
336 gfp_t gfp_mask = GFP_KERNEL;
338 if (sht->unchecked_isa_dma && privsize)
339 gfp_mask |= __GFP_DMA;
341 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
345 shost->host_lock = &shost->default_lock;
346 spin_lock_init(shost->host_lock);
347 shost->shost_state = SHOST_CREATED;
348 INIT_LIST_HEAD(&shost->__devices);
349 INIT_LIST_HEAD(&shost->__targets);
350 INIT_LIST_HEAD(&shost->eh_cmd_q);
351 INIT_LIST_HEAD(&shost->starved_list);
352 init_waitqueue_head(&shost->host_wait);
354 mutex_init(&shost->scan_mutex);
357 * subtract one because we increment first then return, but we need to
358 * know what the next host number was before increment
360 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
361 shost->dma_channel = 0xff;
363 /* These three are default values which can be overridden */
364 shost->max_channel = 0;
368 /* Give each shost a default transportt */
369 shost->transportt = &blank_transport_template;
372 * All drivers right now should be able to handle 12 byte
373 * commands. Every so often there are requests for 16 byte
374 * commands, but individual low-level drivers need to certify that
375 * they actually do something sensible with such commands.
377 shost->max_cmd_len = 12;
379 shost->this_id = sht->this_id;
380 shost->can_queue = sht->can_queue;
381 shost->sg_tablesize = sht->sg_tablesize;
382 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
383 shost->cmd_per_lun = sht->cmd_per_lun;
384 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
385 shost->use_clustering = sht->use_clustering;
386 shost->ordered_tag = sht->ordered_tag;
388 if (sht->supported_mode == MODE_UNKNOWN)
389 /* means we didn't set it ... default to INITIATOR */
390 shost->active_mode = MODE_INITIATOR;
392 shost->active_mode = sht->supported_mode;
394 if (sht->max_host_blocked)
395 shost->max_host_blocked = sht->max_host_blocked;
397 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
400 * If the driver imposes no hard sector transfer limit, start at
401 * machine infinity initially.
403 if (sht->max_sectors)
404 shost->max_sectors = sht->max_sectors;
406 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
409 * assume a 4GB boundary, if not set
411 if (sht->dma_boundary)
412 shost->dma_boundary = sht->dma_boundary;
414 shost->dma_boundary = 0xffffffff;
416 device_initialize(&shost->shost_gendev);
417 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
418 shost->shost_gendev.bus = &scsi_bus_type;
419 shost->shost_gendev.type = &scsi_host_type;
421 device_initialize(&shost->shost_dev);
422 shost->shost_dev.parent = &shost->shost_gendev;
423 shost->shost_dev.class = &shost_class;
424 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
425 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
427 shost->ehandler = kthread_run(scsi_error_handler, shost,
428 "scsi_eh_%d", shost->host_no);
429 if (IS_ERR(shost->ehandler)) {
430 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
431 shost->host_no, PTR_ERR(shost->ehandler));
435 scsi_proc_hostdir_add(shost->hostt);
442 EXPORT_SYMBOL(scsi_host_alloc);
444 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
446 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
449 printk(KERN_WARNING "scsi_register() called on new-style "
450 "template for driver %s\n", sht->name);
455 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
458 EXPORT_SYMBOL(scsi_register);
460 void scsi_unregister(struct Scsi_Host *shost)
462 list_del(&shost->sht_legacy_list);
463 scsi_host_put(shost);
465 EXPORT_SYMBOL(scsi_unregister);
467 static int __scsi_host_match(struct device *dev, void *data)
470 unsigned short *hostnum = (unsigned short *)data;
472 p = class_to_shost(dev);
473 return p->host_no == *hostnum;
477 * scsi_host_lookup - get a reference to a Scsi_Host by host no
478 * @hostnum: host number to locate
481 * A pointer to located Scsi_Host or NULL.
483 * The caller must do a scsi_host_put() to drop the reference
484 * that scsi_host_get() took. The put_device() below dropped
485 * the reference from class_find_device().
487 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
490 struct Scsi_Host *shost = NULL;
492 cdev = class_find_device(&shost_class, NULL, &hostnum,
495 shost = scsi_host_get(class_to_shost(cdev));
500 EXPORT_SYMBOL(scsi_host_lookup);
503 * scsi_host_get - inc a Scsi_Host ref count
504 * @shost: Pointer to Scsi_Host to inc.
506 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
508 if ((shost->shost_state == SHOST_DEL) ||
509 !get_device(&shost->shost_gendev))
513 EXPORT_SYMBOL(scsi_host_get);
516 * scsi_host_put - dec a Scsi_Host ref count
517 * @shost: Pointer to Scsi_Host to dec.
519 void scsi_host_put(struct Scsi_Host *shost)
521 put_device(&shost->shost_gendev);
523 EXPORT_SYMBOL(scsi_host_put);
525 int scsi_init_hosts(void)
527 return class_register(&shost_class);
530 void scsi_exit_hosts(void)
532 class_unregister(&shost_class);
535 int scsi_is_host_device(const struct device *dev)
537 return dev->type == &scsi_host_type;
539 EXPORT_SYMBOL(scsi_is_host_device);
542 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
543 * @shost: Pointer to Scsi_Host.
544 * @work: Work to queue for execution.
547 * 1 - work queued for execution
548 * 0 - work is already queued
549 * -EINVAL - work queue doesn't exist
551 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
553 if (unlikely(!shost->work_q)) {
555 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
556 "when no workqueue created.\n", shost->hostt->name);
562 return queue_work(shost->work_q, work);
564 EXPORT_SYMBOL_GPL(scsi_queue_work);
567 * scsi_flush_work - Flush a Scsi_Host's workqueue.
568 * @shost: Pointer to Scsi_Host.
570 void scsi_flush_work(struct Scsi_Host *shost)
572 if (!shost->work_q) {
574 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
575 "when no workqueue created.\n", shost->hostt->name);
580 flush_workqueue(shost->work_q);
582 EXPORT_SYMBOL_GPL(scsi_flush_work);