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>
36 #include <linux/idr.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 DEFINE_IDA(host_index_ida);
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 flush_workqueue(shost->tmf_work_q);
173 scsi_forget_host(shost);
174 mutex_unlock(&shost->scan_mutex);
175 scsi_proc_host_rm(shost);
177 spin_lock_irqsave(shost->host_lock, flags);
178 if (scsi_host_set_state(shost, SHOST_DEL))
179 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
180 spin_unlock_irqrestore(shost->host_lock, flags);
182 transport_unregister_device(&shost->shost_gendev);
183 device_unregister(&shost->shost_dev);
184 device_del(&shost->shost_gendev);
186 EXPORT_SYMBOL(scsi_remove_host);
189 * scsi_add_host_with_dma - add a scsi host with dma device
190 * @shost: scsi host pointer to add
191 * @dev: a struct device of type scsi class
192 * @dma_dev: dma device for the host
194 * Note: You rarely need to worry about this unless you're in a
195 * virtualised host environments, so use the simpler scsi_add_host()
199 * 0 on success / != 0 for error
201 int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
202 struct device *dma_dev)
204 struct scsi_host_template *sht = shost->hostt;
207 shost_printk(KERN_INFO, shost, "%s\n",
208 sht->info ? sht->info(shost) : sht->name);
210 if (!shost->can_queue) {
211 shost_printk(KERN_ERR, shost,
212 "can_queue = 0 no longer supported\n");
216 error = scsi_init_sense_cache(shost);
220 if (shost_use_blk_mq(shost)) {
221 error = scsi_mq_setup_tags(shost);
225 shost->bqt = blk_init_tags(shost->can_queue,
226 shost->hostt->tag_alloc_policy);
233 if (!shost->shost_gendev.parent)
234 shost->shost_gendev.parent = dev ? dev : &platform_bus;
236 dma_dev = shost->shost_gendev.parent;
238 shost->dma_dev = dma_dev;
241 * Increase usage count temporarily here so that calling
242 * scsi_autopm_put_host() will trigger runtime idle if there is
243 * nothing else preventing suspending the device.
245 pm_runtime_get_noresume(&shost->shost_gendev);
246 pm_runtime_set_active(&shost->shost_gendev);
247 pm_runtime_enable(&shost->shost_gendev);
248 device_enable_async_suspend(&shost->shost_gendev);
250 error = device_add(&shost->shost_gendev);
252 goto out_disable_runtime_pm;
254 scsi_host_set_state(shost, SHOST_RUNNING);
255 get_device(shost->shost_gendev.parent);
257 device_enable_async_suspend(&shost->shost_dev);
259 error = device_add(&shost->shost_dev);
263 get_device(&shost->shost_gendev);
265 if (shost->transportt->host_size) {
266 shost->shost_data = kzalloc(shost->transportt->host_size,
268 if (shost->shost_data == NULL) {
274 if (shost->transportt->create_work_queue) {
275 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
276 "scsi_wq_%d", shost->host_no);
277 shost->work_q = create_singlethread_workqueue(
279 if (!shost->work_q) {
281 goto out_free_shost_data;
285 error = scsi_sysfs_add_host(shost);
287 goto out_destroy_host;
289 scsi_proc_host_add(shost);
290 scsi_autopm_put_host(shost);
295 destroy_workqueue(shost->work_q);
297 kfree(shost->shost_data);
299 device_del(&shost->shost_dev);
301 device_del(&shost->shost_gendev);
302 out_disable_runtime_pm:
303 device_disable_async_suspend(&shost->shost_gendev);
304 pm_runtime_disable(&shost->shost_gendev);
305 pm_runtime_set_suspended(&shost->shost_gendev);
306 pm_runtime_put_noidle(&shost->shost_gendev);
307 if (shost_use_blk_mq(shost))
308 scsi_mq_destroy_tags(shost);
312 EXPORT_SYMBOL(scsi_add_host_with_dma);
314 static void scsi_host_dev_release(struct device *dev)
316 struct Scsi_Host *shost = dev_to_shost(dev);
317 struct device *parent = dev->parent;
319 scsi_proc_hostdir_rm(shost->hostt);
321 /* Wait for functions invoked through call_rcu(&shost->rcu, ...) */
324 if (shost->tmf_work_q)
325 destroy_workqueue(shost->tmf_work_q);
327 kthread_stop(shost->ehandler);
329 destroy_workqueue(shost->work_q);
331 if (shost->shost_state == SHOST_CREATED) {
333 * Free the shost_dev device name here if scsi_host_alloc()
334 * and scsi_host_put() have been called but neither
335 * scsi_host_add() nor scsi_host_remove() has been called.
336 * This avoids that the memory allocated for the shost_dev
339 kfree(dev_name(&shost->shost_dev));
342 if (shost_use_blk_mq(shost)) {
343 if (shost->tag_set.tags)
344 scsi_mq_destroy_tags(shost);
347 blk_free_tags(shost->bqt);
350 kfree(shost->shost_data);
352 ida_simple_remove(&host_index_ida, shost->host_no);
359 static int shost_eh_deadline = -1;
361 module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
362 MODULE_PARM_DESC(eh_deadline,
363 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
365 static struct device_type scsi_host_type = {
367 .release = scsi_host_dev_release,
371 * scsi_host_alloc - register a scsi host adapter instance.
372 * @sht: pointer to scsi host template
373 * @privsize: extra bytes to allocate for driver
376 * Allocate a new Scsi_Host and perform basic initialization.
377 * The host is not published to the scsi midlayer until scsi_add_host
381 * Pointer to a new Scsi_Host
383 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
385 struct Scsi_Host *shost;
386 gfp_t gfp_mask = GFP_KERNEL;
389 if (sht->unchecked_isa_dma && privsize)
390 gfp_mask |= __GFP_DMA;
392 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
396 shost->host_lock = &shost->default_lock;
397 spin_lock_init(shost->host_lock);
398 shost->shost_state = SHOST_CREATED;
399 INIT_LIST_HEAD(&shost->__devices);
400 INIT_LIST_HEAD(&shost->__targets);
401 INIT_LIST_HEAD(&shost->eh_cmd_q);
402 INIT_LIST_HEAD(&shost->starved_list);
403 init_waitqueue_head(&shost->host_wait);
404 mutex_init(&shost->scan_mutex);
406 index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
409 shost->host_no = index;
411 shost->dma_channel = 0xff;
413 /* These three are default values which can be overridden */
414 shost->max_channel = 0;
418 /* Give each shost a default transportt */
419 shost->transportt = &blank_transport_template;
422 * All drivers right now should be able to handle 12 byte
423 * commands. Every so often there are requests for 16 byte
424 * commands, but individual low-level drivers need to certify that
425 * they actually do something sensible with such commands.
427 shost->max_cmd_len = 12;
429 shost->this_id = sht->this_id;
430 shost->can_queue = sht->can_queue;
431 shost->sg_tablesize = sht->sg_tablesize;
432 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
433 shost->cmd_per_lun = sht->cmd_per_lun;
434 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
435 shost->use_clustering = sht->use_clustering;
436 shost->no_write_same = sht->no_write_same;
438 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
439 shost->eh_deadline = -1;
440 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
441 shost_printk(KERN_WARNING, shost,
442 "eh_deadline %u too large, setting to %u\n",
443 shost_eh_deadline, INT_MAX / HZ);
444 shost->eh_deadline = INT_MAX;
446 shost->eh_deadline = shost_eh_deadline * HZ;
448 if (sht->supported_mode == MODE_UNKNOWN)
449 /* means we didn't set it ... default to INITIATOR */
450 shost->active_mode = MODE_INITIATOR;
452 shost->active_mode = sht->supported_mode;
454 if (sht->max_host_blocked)
455 shost->max_host_blocked = sht->max_host_blocked;
457 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
460 * If the driver imposes no hard sector transfer limit, start at
461 * machine infinity initially.
463 if (sht->max_sectors)
464 shost->max_sectors = sht->max_sectors;
466 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
469 * assume a 4GB boundary, if not set
471 if (sht->dma_boundary)
472 shost->dma_boundary = sht->dma_boundary;
474 shost->dma_boundary = 0xffffffff;
476 shost->use_blk_mq = scsi_use_blk_mq;
478 device_initialize(&shost->shost_gendev);
479 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
480 shost->shost_gendev.bus = &scsi_bus_type;
481 shost->shost_gendev.type = &scsi_host_type;
483 device_initialize(&shost->shost_dev);
484 shost->shost_dev.parent = &shost->shost_gendev;
485 shost->shost_dev.class = &shost_class;
486 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
487 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
489 shost->ehandler = kthread_run(scsi_error_handler, shost,
490 "scsi_eh_%d", shost->host_no);
491 if (IS_ERR(shost->ehandler)) {
492 shost_printk(KERN_WARNING, shost,
493 "error handler thread failed to spawn, error = %ld\n",
494 PTR_ERR(shost->ehandler));
495 goto fail_index_remove;
498 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
499 WQ_UNBOUND | WQ_MEM_RECLAIM,
501 if (!shost->tmf_work_q) {
502 shost_printk(KERN_WARNING, shost,
503 "failed to create tmf workq\n");
506 scsi_proc_hostdir_add(shost->hostt);
510 kthread_stop(shost->ehandler);
512 ida_simple_remove(&host_index_ida, shost->host_no);
517 EXPORT_SYMBOL(scsi_host_alloc);
519 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
521 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
524 printk(KERN_WARNING "scsi_register() called on new-style "
525 "template for driver %s\n", sht->name);
530 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
533 EXPORT_SYMBOL(scsi_register);
535 void scsi_unregister(struct Scsi_Host *shost)
537 list_del(&shost->sht_legacy_list);
538 scsi_host_put(shost);
540 EXPORT_SYMBOL(scsi_unregister);
542 static int __scsi_host_match(struct device *dev, const void *data)
545 const unsigned short *hostnum = data;
547 p = class_to_shost(dev);
548 return p->host_no == *hostnum;
552 * scsi_host_lookup - get a reference to a Scsi_Host by host no
553 * @hostnum: host number to locate
556 * A pointer to located Scsi_Host or NULL.
558 * The caller must do a scsi_host_put() to drop the reference
559 * that scsi_host_get() took. The put_device() below dropped
560 * the reference from class_find_device().
562 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
565 struct Scsi_Host *shost = NULL;
567 cdev = class_find_device(&shost_class, NULL, &hostnum,
570 shost = scsi_host_get(class_to_shost(cdev));
575 EXPORT_SYMBOL(scsi_host_lookup);
578 * scsi_host_get - inc a Scsi_Host ref count
579 * @shost: Pointer to Scsi_Host to inc.
581 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
583 if ((shost->shost_state == SHOST_DEL) ||
584 !get_device(&shost->shost_gendev))
588 EXPORT_SYMBOL(scsi_host_get);
591 * scsi_host_put - dec a Scsi_Host ref count
592 * @shost: Pointer to Scsi_Host to dec.
594 void scsi_host_put(struct Scsi_Host *shost)
596 put_device(&shost->shost_gendev);
598 EXPORT_SYMBOL(scsi_host_put);
600 int scsi_init_hosts(void)
602 return class_register(&shost_class);
605 void scsi_exit_hosts(void)
607 class_unregister(&shost_class);
608 ida_destroy(&host_index_ida);
611 int scsi_is_host_device(const struct device *dev)
613 return dev->type == &scsi_host_type;
615 EXPORT_SYMBOL(scsi_is_host_device);
618 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
619 * @shost: Pointer to Scsi_Host.
620 * @work: Work to queue for execution.
623 * 1 - work queued for execution
624 * 0 - work is already queued
625 * -EINVAL - work queue doesn't exist
627 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
629 if (unlikely(!shost->work_q)) {
630 shost_printk(KERN_ERR, shost,
631 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
632 "when no workqueue created.\n", shost->hostt->name);
638 return queue_work(shost->work_q, work);
640 EXPORT_SYMBOL_GPL(scsi_queue_work);
643 * scsi_flush_work - Flush a Scsi_Host's workqueue.
644 * @shost: Pointer to Scsi_Host.
646 void scsi_flush_work(struct Scsi_Host *shost)
648 if (!shost->work_q) {
649 shost_printk(KERN_ERR, shost,
650 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
651 "when no workqueue created.\n", shost->hostt->name);
656 flush_workqueue(shost->work_q);
658 EXPORT_SYMBOL_GPL(scsi_flush_work);