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 = ATOMIC_INIT(0); /* 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 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 printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
208 sht->info ? sht->info(shost) : sht->name);
210 if (!shost->can_queue) {
211 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
216 error = scsi_setup_command_freelist(shost);
220 if (!shost->shost_gendev.parent)
221 shost->shost_gendev.parent = dev ? dev : &platform_bus;
223 dma_dev = shost->shost_gendev.parent;
225 shost->dma_dev = dma_dev;
227 error = device_add(&shost->shost_gendev);
231 pm_runtime_set_active(&shost->shost_gendev);
232 pm_runtime_enable(&shost->shost_gendev);
233 device_enable_async_suspend(&shost->shost_gendev);
235 scsi_host_set_state(shost, SHOST_RUNNING);
236 get_device(shost->shost_gendev.parent);
238 device_enable_async_suspend(&shost->shost_dev);
240 error = device_add(&shost->shost_dev);
244 get_device(&shost->shost_gendev);
246 if (shost->transportt->host_size) {
247 shost->shost_data = kzalloc(shost->transportt->host_size,
249 if (shost->shost_data == NULL) {
255 if (shost->transportt->create_work_queue) {
256 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
257 "scsi_wq_%d", shost->host_no);
258 shost->work_q = create_singlethread_workqueue(
260 if (!shost->work_q) {
262 goto out_free_shost_data;
266 error = scsi_sysfs_add_host(shost);
268 goto out_destroy_host;
270 scsi_proc_host_add(shost);
275 destroy_workqueue(shost->work_q);
277 kfree(shost->shost_data);
279 device_del(&shost->shost_dev);
281 device_del(&shost->shost_gendev);
283 scsi_destroy_command_freelist(shost);
287 EXPORT_SYMBOL(scsi_add_host_with_dma);
289 static void scsi_host_dev_release(struct device *dev)
291 struct Scsi_Host *shost = dev_to_shost(dev);
292 struct device *parent = dev->parent;
293 struct request_queue *q;
296 scsi_proc_hostdir_rm(shost->hostt);
298 if (shost->tmf_work_q)
299 destroy_workqueue(shost->tmf_work_q);
301 kthread_stop(shost->ehandler);
303 destroy_workqueue(shost->work_q);
304 q = shost->uspace_req_q;
306 queuedata = q->queuedata;
307 blk_cleanup_queue(q);
311 scsi_destroy_command_freelist(shost);
313 blk_free_tags(shost->bqt);
315 kfree(shost->shost_data);
322 static int shost_eh_deadline = -1;
324 module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR);
325 MODULE_PARM_DESC(eh_deadline,
326 "SCSI EH timeout in seconds (should be between 0 and 2^31-1)");
328 static struct device_type scsi_host_type = {
330 .release = scsi_host_dev_release,
334 * scsi_host_alloc - register a scsi host adapter instance.
335 * @sht: pointer to scsi host template
336 * @privsize: extra bytes to allocate for driver
339 * Allocate a new Scsi_Host and perform basic initialization.
340 * The host is not published to the scsi midlayer until scsi_add_host
344 * Pointer to a new Scsi_Host
346 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
348 struct Scsi_Host *shost;
349 gfp_t gfp_mask = GFP_KERNEL;
351 if (sht->unchecked_isa_dma && privsize)
352 gfp_mask |= __GFP_DMA;
354 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
358 shost->host_lock = &shost->default_lock;
359 spin_lock_init(shost->host_lock);
360 shost->shost_state = SHOST_CREATED;
361 INIT_LIST_HEAD(&shost->__devices);
362 INIT_LIST_HEAD(&shost->__targets);
363 INIT_LIST_HEAD(&shost->eh_cmd_q);
364 INIT_LIST_HEAD(&shost->starved_list);
365 init_waitqueue_head(&shost->host_wait);
366 mutex_init(&shost->scan_mutex);
369 * subtract one because we increment first then return, but we need to
370 * know what the next host number was before increment
372 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
373 shost->dma_channel = 0xff;
375 /* These three are default values which can be overridden */
376 shost->max_channel = 0;
380 /* Give each shost a default transportt */
381 shost->transportt = &blank_transport_template;
384 * All drivers right now should be able to handle 12 byte
385 * commands. Every so often there are requests for 16 byte
386 * commands, but individual low-level drivers need to certify that
387 * they actually do something sensible with such commands.
389 shost->max_cmd_len = 12;
391 shost->this_id = sht->this_id;
392 shost->can_queue = sht->can_queue;
393 shost->sg_tablesize = sht->sg_tablesize;
394 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
395 shost->cmd_per_lun = sht->cmd_per_lun;
396 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
397 shost->use_clustering = sht->use_clustering;
398 shost->ordered_tag = sht->ordered_tag;
399 shost->no_write_same = sht->no_write_same;
401 if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)
402 shost->eh_deadline = -1;
403 else if ((ulong) shost_eh_deadline * HZ > INT_MAX) {
404 shost_printk(KERN_WARNING, shost,
405 "eh_deadline %u too large, setting to %u\n",
406 shost_eh_deadline, INT_MAX / HZ);
407 shost->eh_deadline = INT_MAX;
409 shost->eh_deadline = shost_eh_deadline * HZ;
411 if (sht->supported_mode == MODE_UNKNOWN)
412 /* means we didn't set it ... default to INITIATOR */
413 shost->active_mode = MODE_INITIATOR;
415 shost->active_mode = sht->supported_mode;
417 if (sht->max_host_blocked)
418 shost->max_host_blocked = sht->max_host_blocked;
420 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
423 * If the driver imposes no hard sector transfer limit, start at
424 * machine infinity initially.
426 if (sht->max_sectors)
427 shost->max_sectors = sht->max_sectors;
429 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
432 * assume a 4GB boundary, if not set
434 if (sht->dma_boundary)
435 shost->dma_boundary = sht->dma_boundary;
437 shost->dma_boundary = 0xffffffff;
439 device_initialize(&shost->shost_gendev);
440 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
441 shost->shost_gendev.bus = &scsi_bus_type;
442 shost->shost_gendev.type = &scsi_host_type;
444 device_initialize(&shost->shost_dev);
445 shost->shost_dev.parent = &shost->shost_gendev;
446 shost->shost_dev.class = &shost_class;
447 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
448 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
450 shost->ehandler = kthread_run(scsi_error_handler, shost,
451 "scsi_eh_%d", shost->host_no);
452 if (IS_ERR(shost->ehandler)) {
453 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
454 shost->host_no, PTR_ERR(shost->ehandler));
458 shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
459 WQ_UNBOUND | WQ_MEM_RECLAIM,
461 if (!shost->tmf_work_q) {
462 printk(KERN_WARNING "scsi%d: failed to create tmf workq\n",
466 scsi_proc_hostdir_add(shost->hostt);
470 kthread_stop(shost->ehandler);
475 EXPORT_SYMBOL(scsi_host_alloc);
477 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
479 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
482 printk(KERN_WARNING "scsi_register() called on new-style "
483 "template for driver %s\n", sht->name);
488 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
491 EXPORT_SYMBOL(scsi_register);
493 void scsi_unregister(struct Scsi_Host *shost)
495 list_del(&shost->sht_legacy_list);
496 scsi_host_put(shost);
498 EXPORT_SYMBOL(scsi_unregister);
500 static int __scsi_host_match(struct device *dev, const void *data)
503 const unsigned short *hostnum = data;
505 p = class_to_shost(dev);
506 return p->host_no == *hostnum;
510 * scsi_host_lookup - get a reference to a Scsi_Host by host no
511 * @hostnum: host number to locate
514 * A pointer to located Scsi_Host or NULL.
516 * The caller must do a scsi_host_put() to drop the reference
517 * that scsi_host_get() took. The put_device() below dropped
518 * the reference from class_find_device().
520 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
523 struct Scsi_Host *shost = NULL;
525 cdev = class_find_device(&shost_class, NULL, &hostnum,
528 shost = scsi_host_get(class_to_shost(cdev));
533 EXPORT_SYMBOL(scsi_host_lookup);
536 * scsi_host_get - inc a Scsi_Host ref count
537 * @shost: Pointer to Scsi_Host to inc.
539 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
541 if ((shost->shost_state == SHOST_DEL) ||
542 !get_device(&shost->shost_gendev))
546 EXPORT_SYMBOL(scsi_host_get);
549 * scsi_host_put - dec a Scsi_Host ref count
550 * @shost: Pointer to Scsi_Host to dec.
552 void scsi_host_put(struct Scsi_Host *shost)
554 put_device(&shost->shost_gendev);
556 EXPORT_SYMBOL(scsi_host_put);
558 int scsi_init_hosts(void)
560 return class_register(&shost_class);
563 void scsi_exit_hosts(void)
565 class_unregister(&shost_class);
568 int scsi_is_host_device(const struct device *dev)
570 return dev->type == &scsi_host_type;
572 EXPORT_SYMBOL(scsi_is_host_device);
575 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
576 * @shost: Pointer to Scsi_Host.
577 * @work: Work to queue for execution.
580 * 1 - work queued for execution
581 * 0 - work is already queued
582 * -EINVAL - work queue doesn't exist
584 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
586 if (unlikely(!shost->work_q)) {
588 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
589 "when no workqueue created.\n", shost->hostt->name);
595 return queue_work(shost->work_q, work);
597 EXPORT_SYMBOL_GPL(scsi_queue_work);
600 * scsi_flush_work - Flush a Scsi_Host's workqueue.
601 * @shost: Pointer to Scsi_Host.
603 void scsi_flush_work(struct Scsi_Host *shost)
605 if (!shost->work_q) {
607 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
608 "when no workqueue created.\n", shost->hostt->name);
613 flush_workqueue(shost->work_q);
615 EXPORT_SYMBOL_GPL(scsi_flush_work);