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;
292 scsi_proc_hostdir_rm(shost->hostt);
295 kthread_stop(shost->ehandler);
297 destroy_workqueue(shost->work_q);
298 q = shost->uspace_req_q;
300 queuedata = q->queuedata;
301 blk_cleanup_queue(q);
305 scsi_destroy_command_freelist(shost);
307 blk_free_tags(shost->bqt);
309 kfree(shost->shost_data);
316 static struct device_type scsi_host_type = {
318 .release = scsi_host_dev_release,
322 * scsi_host_alloc - register a scsi host adapter instance.
323 * @sht: pointer to scsi host template
324 * @privsize: extra bytes to allocate for driver
327 * Allocate a new Scsi_Host and perform basic initialization.
328 * The host is not published to the scsi midlayer until scsi_add_host
332 * Pointer to a new Scsi_Host
334 struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
336 struct Scsi_Host *shost;
337 gfp_t gfp_mask = GFP_KERNEL;
339 if (sht->unchecked_isa_dma && privsize)
340 gfp_mask |= __GFP_DMA;
342 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
346 shost->host_lock = &shost->default_lock;
347 spin_lock_init(shost->host_lock);
348 shost->shost_state = SHOST_CREATED;
349 INIT_LIST_HEAD(&shost->__devices);
350 INIT_LIST_HEAD(&shost->__targets);
351 INIT_LIST_HEAD(&shost->eh_cmd_q);
352 INIT_LIST_HEAD(&shost->starved_list);
353 init_waitqueue_head(&shost->host_wait);
355 mutex_init(&shost->scan_mutex);
358 * subtract one because we increment first then return, but we need to
359 * know what the next host number was before increment
361 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
362 shost->dma_channel = 0xff;
364 /* These three are default values which can be overridden */
365 shost->max_channel = 0;
369 /* Give each shost a default transportt */
370 shost->transportt = &blank_transport_template;
373 * All drivers right now should be able to handle 12 byte
374 * commands. Every so often there are requests for 16 byte
375 * commands, but individual low-level drivers need to certify that
376 * they actually do something sensible with such commands.
378 shost->max_cmd_len = 12;
380 shost->this_id = sht->this_id;
381 shost->can_queue = sht->can_queue;
382 shost->sg_tablesize = sht->sg_tablesize;
383 shost->sg_prot_tablesize = sht->sg_prot_tablesize;
384 shost->cmd_per_lun = sht->cmd_per_lun;
385 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
386 shost->use_clustering = sht->use_clustering;
387 shost->ordered_tag = sht->ordered_tag;
389 if (sht->supported_mode == MODE_UNKNOWN)
390 /* means we didn't set it ... default to INITIATOR */
391 shost->active_mode = MODE_INITIATOR;
393 shost->active_mode = sht->supported_mode;
395 if (sht->max_host_blocked)
396 shost->max_host_blocked = sht->max_host_blocked;
398 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
401 * If the driver imposes no hard sector transfer limit, start at
402 * machine infinity initially.
404 if (sht->max_sectors)
405 shost->max_sectors = sht->max_sectors;
407 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
410 * assume a 4GB boundary, if not set
412 if (sht->dma_boundary)
413 shost->dma_boundary = sht->dma_boundary;
415 shost->dma_boundary = 0xffffffff;
417 device_initialize(&shost->shost_gendev);
418 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
419 shost->shost_gendev.bus = &scsi_bus_type;
420 shost->shost_gendev.type = &scsi_host_type;
422 device_initialize(&shost->shost_dev);
423 shost->shost_dev.parent = &shost->shost_gendev;
424 shost->shost_dev.class = &shost_class;
425 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
426 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
428 shost->ehandler = kthread_run(scsi_error_handler, shost,
429 "scsi_eh_%d", shost->host_no);
430 if (IS_ERR(shost->ehandler)) {
431 printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
432 shost->host_no, PTR_ERR(shost->ehandler));
436 scsi_proc_hostdir_add(shost->hostt);
443 EXPORT_SYMBOL(scsi_host_alloc);
445 struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
447 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
450 printk(KERN_WARNING "scsi_register() called on new-style "
451 "template for driver %s\n", sht->name);
456 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
459 EXPORT_SYMBOL(scsi_register);
461 void scsi_unregister(struct Scsi_Host *shost)
463 list_del(&shost->sht_legacy_list);
464 scsi_host_put(shost);
466 EXPORT_SYMBOL(scsi_unregister);
468 static int __scsi_host_match(struct device *dev, void *data)
471 unsigned short *hostnum = (unsigned short *)data;
473 p = class_to_shost(dev);
474 return p->host_no == *hostnum;
478 * scsi_host_lookup - get a reference to a Scsi_Host by host no
479 * @hostnum: host number to locate
482 * A pointer to located Scsi_Host or NULL.
484 * The caller must do a scsi_host_put() to drop the reference
485 * that scsi_host_get() took. The put_device() below dropped
486 * the reference from class_find_device().
488 struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
491 struct Scsi_Host *shost = NULL;
493 cdev = class_find_device(&shost_class, NULL, &hostnum,
496 shost = scsi_host_get(class_to_shost(cdev));
501 EXPORT_SYMBOL(scsi_host_lookup);
504 * scsi_host_get - inc a Scsi_Host ref count
505 * @shost: Pointer to Scsi_Host to inc.
507 struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
509 if ((shost->shost_state == SHOST_DEL) ||
510 !get_device(&shost->shost_gendev))
514 EXPORT_SYMBOL(scsi_host_get);
517 * scsi_host_put - dec a Scsi_Host ref count
518 * @shost: Pointer to Scsi_Host to dec.
520 void scsi_host_put(struct Scsi_Host *shost)
522 put_device(&shost->shost_gendev);
524 EXPORT_SYMBOL(scsi_host_put);
526 int scsi_init_hosts(void)
528 return class_register(&shost_class);
531 void scsi_exit_hosts(void)
533 class_unregister(&shost_class);
536 int scsi_is_host_device(const struct device *dev)
538 return dev->type == &scsi_host_type;
540 EXPORT_SYMBOL(scsi_is_host_device);
543 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
544 * @shost: Pointer to Scsi_Host.
545 * @work: Work to queue for execution.
548 * 1 - work queued for execution
549 * 0 - work is already queued
550 * -EINVAL - work queue doesn't exist
552 int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
554 if (unlikely(!shost->work_q)) {
556 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
557 "when no workqueue created.\n", shost->hostt->name);
563 return queue_work(shost->work_q, work);
565 EXPORT_SYMBOL_GPL(scsi_queue_work);
568 * scsi_flush_work - Flush a Scsi_Host's workqueue.
569 * @shost: Pointer to Scsi_Host.
571 void scsi_flush_work(struct Scsi_Host *shost)
573 if (!shost->work_q) {
575 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
576 "when no workqueue created.\n", shost->hostt->name);
581 flush_workqueue(shost->work_q);
583 EXPORT_SYMBOL_GPL(scsi_flush_work);