[net-next-2.6.git] / drivers / scsi / hosts.c

/*
 *  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/slab.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 atomic_t 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);
	scsi_forget_host(shost);
	mutex_unlock(&shost->scan_mutex);
	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);
}
EXPORT_SYMBOL(scsi_remove_host);

/**
 * scsi_add_host_with_dma - add a scsi host with dma device
 * @shost:	scsi host pointer to add
 * @dev:	a struct device of type scsi class
 * @dma_dev:	dma device for the host
 *
 * Note: You rarely need to worry about this unless you're in a
 * virtualised host environments, so use the simpler scsi_add_host()
 * function instead.
 *
 * Return value: 
 * 	0 on success / != 0 for error
 **/
int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
			   struct device *dma_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;
	shost->dma_dev = dma_dev;

	device_enable_async_suspend(&shost->shost_gendev);

	error = device_add(&shost->shost_gendev);
	if (error)
		goto out;

	scsi_host_set_state(shost, SHOST_RUNNING);
	get_device(shost->shost_gendev.parent);

	device_enable_async_suspend(&shost->shost_dev);

	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, sizeof(shost->work_q_name),
			 "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_with_dma);

static void scsi_host_dev_release(struct device *dev)
{
	struct Scsi_Host *shost = dev_to_shost(dev);
	struct device *parent = dev->parent;

	scsi_proc_hostdir_rm(shost->hostt);

	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);

	/*
	 * subtract one because we increment first then return, but we need to
	 * know what the next host number was before increment
	 */
	shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
	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);
	dev_set_name(&shost->shost_gendev, "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;
	dev_set_name(&shost->shost_dev, "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 = NULL;

	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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* hosts.c Copyright (C) 1992 Drew Eckhardt
	3	* Copyright (C) 1993, 1994, 1995 Eric Youngdale
	4	* Copyright (C) 2002-2003 Christoph Hellwig
	5	*
	6	* mid to lowlevel SCSI driver interface
	7	* Initial versions: Drew Eckhardt
	8	* Subsequent revisions: Eric Youngdale
	9	*
	10	* <drew@colorado.edu>
	11	*
	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
	15	*
	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>
	19	*
	20	* Restructured scsi_host lists and associated functions.
	21	* September 04, 2002 Mike Anderson (andmike@us.ibm.com)
	22	*/
	23
	24	#include <linux/module.h>
	25	#include <linux/blkdev.h>
	26	#include <linux/kernel.h>
5a0e3ad6	27	#include <linux/slab.h>
c5478def	28	#include <linux/kthread.h>
1da177e4 LT	29	#include <linux/string.h>
	30	#include <linux/mm.h>
	31	#include <linux/init.h>
	32	#include <linux/completion.h>
	33	#include <linux/transport_class.h>
d052d1be	34	#include <linux/platform_device.h>
1da177e4 LT	35
	36	#include <scsi/scsi_device.h>
	37	#include <scsi/scsi_host.h>
	38	#include <scsi/scsi_transport.h>
	39
	40	#include "scsi_priv.h"
	41	#include "scsi_logging.h"
	42
	43
30c9afa6	44	static atomic_t scsi_host_next_hn; /* host_no for next new host */
1da177e4 LT	45
1da177e4 LT	46
ee959b00	47	static void scsi_host_cls_release(struct device *dev)
1da177e4	48	{
ee959b00	49	put_device(&class_to_shost(dev)->shost_gendev);
1da177e4 LT	50	}
	51
	52	static struct class shost_class = {
	53	.name = "scsi_host",
ee959b00	54	.dev_release = scsi_host_cls_release,
1da177e4 LT	55	};
1da177e4 LT	56
d3301874	57	/**
eb44820c	58	* scsi_host_set_state - Take the given host through the host state model.
d3301874 MA	59	* @shost: scsi host to change the state of.
	60	* @state: state to change to.
	61	*
	62	* Returns zero if unsuccessful or an error if the requested
	63	* transition is illegal.
	64	**/
	65	int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
	66	{
	67	enum scsi_host_state oldstate = shost->shost_state;
	68
	69	if (state == oldstate)
	70	return 0;
	71
	72	switch (state) {
	73	case SHOST_CREATED:
	74	/* There are no legal states that come back to
	75	* created. This is the manually initialised start
	76	* state */
	77	goto illegal;
	78
	79	case SHOST_RUNNING:
	80	switch (oldstate) {
	81	case SHOST_CREATED:
	82	case SHOST_RECOVERY:
	83	break;
	84	default:
	85	goto illegal;
	86	}
	87	break;
	88
	89	case SHOST_RECOVERY:
	90	switch (oldstate) {
	91	case SHOST_RUNNING:
	92	break;
	93	default:
	94	goto illegal;
	95	}
	96	break;
	97
	98	case SHOST_CANCEL:
	99	switch (oldstate) {
	100	case SHOST_CREATED:
	101	case SHOST_RUNNING:
939647ee	102	case SHOST_CANCEL_RECOVERY:
d3301874 MA	103	break;
	104	default:
	105	goto illegal;
	106	}
	107	break;
	108
	109	case SHOST_DEL:
	110	switch (oldstate) {
	111	case SHOST_CANCEL:
939647ee	112	case SHOST_DEL_RECOVERY:
d3301874 MA	113	break;
	114	default:
	115	goto illegal;
	116	}
	117	break;
	118
939647ee JB	119	case SHOST_CANCEL_RECOVERY:
	120	switch (oldstate) {
	121	case SHOST_CANCEL:
	122	case SHOST_RECOVERY:
	123	break;
	124	default:
	125	goto illegal;
	126	}
	127	break;
	128
	129	case SHOST_DEL_RECOVERY:
	130	switch (oldstate) {
	131	case SHOST_CANCEL_RECOVERY:
	132	break;
	133	default:
	134	goto illegal;
	135	}
	136	break;
d3301874 MA	137	}
	138	shost->shost_state = state;
	139	return 0;
	140
	141	illegal:
	142	SCSI_LOG_ERROR_RECOVERY(1,
9ccfc756 JB	143	shost_printk(KERN_ERR, shost,
	144	"Illegal host state transition"
	145	"%s->%s\n",
	146	scsi_host_state_name(oldstate),
	147	scsi_host_state_name(state)));
d3301874 MA	148	return -EINVAL;
	149	}
	150	EXPORT_SYMBOL(scsi_host_set_state);
	151
1da177e4 LT	152	/**
	153	* scsi_remove_host - remove a scsi host
	154	* @shost: a pointer to a scsi host to remove
	155	**/
	156	void scsi_remove_host(struct Scsi_Host *shost)
	157	{
939647ee	158	unsigned long flags;
0b950672	159	mutex_lock(&shost->scan_mutex);
939647ee JB	160	spin_lock_irqsave(shost->host_lock, flags);
	161	if (scsi_host_set_state(shost, SHOST_CANCEL))
	162	if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
	163	spin_unlock_irqrestore(shost->host_lock, flags);
0b950672	164	mutex_unlock(&shost->scan_mutex);
939647ee JB	165	return;
	166	}
	167	spin_unlock_irqrestore(shost->host_lock, flags);
1da177e4	168	scsi_forget_host(shost);
4e46bf89	169	mutex_unlock(&shost->scan_mutex);
1da177e4 LT	170	scsi_proc_host_rm(shost);
1da177e4 LT	171
939647ee JB	172	spin_lock_irqsave(shost->host_lock, flags);
	173	if (scsi_host_set_state(shost, SHOST_DEL))
	174	BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
	175	spin_unlock_irqrestore(shost->host_lock, flags);
1da177e4 LT	176
1da177e4 LT	177	transport_unregister_device(&shost->shost_gendev);
ee959b00	178	device_unregister(&shost->shost_dev);
1da177e4 LT	179	device_del(&shost->shost_gendev);
	180	}
	181	EXPORT_SYMBOL(scsi_remove_host);
	182
	183	/**
d139b9bd	184	* scsi_add_host_with_dma - add a scsi host with dma device
1da177e4 LT	185	* @shost: scsi host pointer to add
1da177e4 LT	186	* @dev: a struct device of type scsi class
d139b9bd JB	187	* @dma_dev: dma device for the host
	188	*
	189	* Note: You rarely need to worry about this unless you're in a
	190	* virtualised host environments, so use the simpler scsi_add_host()
	191	* function instead.
1da177e4 LT	192	*
	193	* Return value:
	194	* 0 on success / != 0 for error
	195	**/
d139b9bd JB	196	int scsi_add_host_with_dma(struct Scsi_Host shost, struct device dev,
d139b9bd JB	197	struct device *dma_dev)
1da177e4 LT	198	{
	199	struct scsi_host_template *sht = shost->hostt;
	200	int error = -EINVAL;
	201
	202	printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
	203	sht->info ? sht->info(shost) : sht->name);
	204
	205	if (!shost->can_queue) {
	206	printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
	207	sht->name);
542bd137	208	goto fail;
1da177e4 LT	209	}
1da177e4 LT	210
542bd137 JB	211	error = scsi_setup_command_freelist(shost);
	212	if (error)
	213	goto fail;
	214
1da177e4 LT	215	if (!shost->shost_gendev.parent)
1da177e4 LT	216	shost->shost_gendev.parent = dev ? dev : &platform_bus;
d139b9bd	217	shost->dma_dev = dma_dev;
1da177e4	218
4cb077d9 RW	219	device_enable_async_suspend(&shost->shost_gendev);
4cb077d9 RW	220
1da177e4 LT	221	error = device_add(&shost->shost_gendev);
	222	if (error)
	223	goto out;
	224
d3301874	225	scsi_host_set_state(shost, SHOST_RUNNING);
1da177e4 LT	226	get_device(shost->shost_gendev.parent);
1da177e4 LT	227
4cb077d9 RW	228	device_enable_async_suspend(&shost->shost_dev);
4cb077d9 RW	229
ee959b00	230	error = device_add(&shost->shost_dev);
1da177e4 LT	231	if (error)
	232	goto out_del_gendev;
	233
	234	get_device(&shost->shost_gendev);
	235
77cca462 JS	236	if (shost->transportt->host_size) {
	237	shost->shost_data = kzalloc(shost->transportt->host_size,
	238	GFP_KERNEL);
	239	if (shost->shost_data == NULL) {
	240	error = -ENOMEM;
ee959b00	241	goto out_del_dev;
77cca462 JS	242	}
77cca462 JS	243	}
1da177e4 LT	244
1da177e4 LT	245	if (shost->transportt->create_work_queue) {
aab0de24 KS	246	snprintf(shost->work_q_name, sizeof(shost->work_q_name),
aab0de24 KS	247	"scsi_wq_%d", shost->host_no);
1da177e4 LT	248	shost->work_q = create_singlethread_workqueue(
1da177e4 LT	249	shost->work_q_name);
77cca462 JS	250	if (!shost->work_q) {
77cca462 JS	251	error = -EINVAL;
1da177e4	252	goto out_free_shost_data;
77cca462	253	}
1da177e4 LT	254	}
	255
	256	error = scsi_sysfs_add_host(shost);
	257	if (error)
	258	goto out_destroy_host;
	259
	260	scsi_proc_host_add(shost);
	261	return error;
	262
	263	out_destroy_host:
	264	if (shost->work_q)
	265	destroy_workqueue(shost->work_q);
	266	out_free_shost_data:
	267	kfree(shost->shost_data);
ee959b00 TJ	268	out_del_dev:
ee959b00 TJ	269	device_del(&shost->shost_dev);
1da177e4 LT	270	out_del_gendev:
	271	device_del(&shost->shost_gendev);
	272	out:
542bd137 JB	273	scsi_destroy_command_freelist(shost);
542bd137 JB	274	fail:
1da177e4 LT	275	return error;
1da177e4 LT	276	}
d139b9bd	277	EXPORT_SYMBOL(scsi_add_host_with_dma);
1da177e4 LT	278
	279	static void scsi_host_dev_release(struct device *dev)
	280	{
	281	struct Scsi_Host *shost = dev_to_shost(dev);
	282	struct device *parent = dev->parent;
	283
77c01976 AS	284	scsi_proc_hostdir_rm(shost->hostt);
77c01976 AS	285
c5478def CH	286	if (shost->ehandler)
c5478def CH	287	kthread_stop(shost->ehandler);
1da177e4 LT	288	if (shost->work_q)
1da177e4 LT	289	destroy_workqueue(shost->work_q);
b58d9154 FT	290	if (shost->uspace_req_q) {
	291	kfree(shost->uspace_req_q->queuedata);
	292	scsi_free_queue(shost->uspace_req_q);
	293	}
1da177e4	294
1da177e4	295	scsi_destroy_command_freelist(shost);
86e33a29 JB	296	if (shost->bqt)
	297	blk_free_tags(shost->bqt);
	298
1da177e4 LT	299	kfree(shost->shost_data);
1da177e4 LT	300
1da177e4 LT	301	if (parent)
	302	put_device(parent);
	303	kfree(shost);
	304	}
	305
453cd0f3	306	static struct device_type scsi_host_type = {
b0ed4336 HR	307	.name = "scsi_host",
	308	.release = scsi_host_dev_release,
	309	};
	310
1da177e4 LT	311	/**
	312	* scsi_host_alloc - register a scsi host adapter instance.
	313	* @sht: pointer to scsi host template
	314	* @privsize: extra bytes to allocate for driver
	315	*
	316	* Note:
	317	* Allocate a new Scsi_Host and perform basic initialization.
	318	* The host is not published to the scsi midlayer until scsi_add_host
	319	* is called.
	320	*
	321	* Return value:
	322	* Pointer to a new Scsi_Host
	323	**/
	324	struct Scsi_Host scsi_host_alloc(struct scsi_host_template sht, int privsize)
	325	{
	326	struct Scsi_Host *shost;
c53033f6 AV	327	gfp_t gfp_mask = GFP_KERNEL;
c53033f6 AV	328	int rval;
1da177e4 LT	329
	330	if (sht->unchecked_isa_dma && privsize)
	331	gfp_mask \|= __GFP_DMA;
	332
24669f75	333	shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
1da177e4 LT	334	if (!shost)
1da177e4 LT	335	return NULL;
1da177e4	336
4f777ed2 CH	337	shost->host_lock = &shost->default_lock;
4f777ed2 CH	338	spin_lock_init(shost->host_lock);
d3301874	339	shost->shost_state = SHOST_CREATED;
1da177e4 LT	340	INIT_LIST_HEAD(&shost->__devices);
	341	INIT_LIST_HEAD(&shost->__targets);
	342	INIT_LIST_HEAD(&shost->eh_cmd_q);
	343	INIT_LIST_HEAD(&shost->starved_list);
	344	init_waitqueue_head(&shost->host_wait);
	345
0b950672	346	mutex_init(&shost->scan_mutex);
1da177e4	347
30c9afa6 JE	348	/*
	349	* subtract one because we increment first then return, but we need to
	350	* know what the next host number was before increment
	351	*/
	352	shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
1da177e4 LT	353	shost->dma_channel = 0xff;
	354
	355	/* These three are default values which can be overridden */
	356	shost->max_channel = 0;
	357	shost->max_id = 8;
	358	shost->max_lun = 8;
	359
	360	/* Give each shost a default transportt */
	361	shost->transportt = &blank_transport_template;
	362
	363	/*
	364	* All drivers right now should be able to handle 12 byte
	365	* commands. Every so often there are requests for 16 byte
	366	* commands, but individual low-level drivers need to certify that
	367	* they actually do something sensible with such commands.
	368	*/
	369	shost->max_cmd_len = 12;
	370	shost->hostt = sht;
	371	shost->this_id = sht->this_id;
	372	shost->can_queue = sht->can_queue;
	373	shost->sg_tablesize = sht->sg_tablesize;
	374	shost->cmd_per_lun = sht->cmd_per_lun;
	375	shost->unchecked_isa_dma = sht->unchecked_isa_dma;
	376	shost->use_clustering = sht->use_clustering;
1da177e4 LT	377	shost->ordered_tag = sht->ordered_tag;
1da177e4 LT	378
7a39ac3f JB	379	if (sht->supported_mode == MODE_UNKNOWN)
	380	/* means we didn't set it ... default to INITIATOR */
	381	shost->active_mode = MODE_INITIATOR;
	382	else
	383	shost->active_mode = sht->supported_mode;
	384
1da177e4 LT	385	if (sht->max_host_blocked)
	386	shost->max_host_blocked = sht->max_host_blocked;
	387	else
	388	shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
	389
	390	/*
	391	* If the driver imposes no hard sector transfer limit, start at
	392	* machine infinity initially.
	393	*/
	394	if (sht->max_sectors)
	395	shost->max_sectors = sht->max_sectors;
	396	else
	397	shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
	398
	399	/*
	400	* assume a 4GB boundary, if not set
	401	*/
	402	if (sht->dma_boundary)
	403	shost->dma_boundary = sht->dma_boundary;
	404	else
	405	shost->dma_boundary = 0xffffffff;
	406
1da177e4	407	device_initialize(&shost->shost_gendev);
71610f55	408	dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
b0ed4336 HR	409	#ifndef CONFIG_SYSFS_DEPRECATED
	410	shost->shost_gendev.bus = &scsi_bus_type;
	411	#endif
	412	shost->shost_gendev.type = &scsi_host_type;
1da177e4	413
ee959b00 TJ	414	device_initialize(&shost->shost_dev);
	415	shost->shost_dev.parent = &shost->shost_gendev;
	416	shost->shost_dev.class = &shost_class;
71610f55	417	dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
f7120a4f	418	shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
1da177e4	419
c5478def CH	420	shost->ehandler = kthread_run(scsi_error_handler, shost,
	421	"scsi_eh_%d", shost->host_no);
	422	if (IS_ERR(shost->ehandler)) {
	423	rval = PTR_ERR(shost->ehandler);
542bd137	424	goto fail_kfree;
c5478def	425	}
1da177e4 LT	426
	427	scsi_proc_hostdir_add(shost->hostt);
	428	return shost;
	429
1da177e4 LT	430	fail_kfree:
	431	kfree(shost);
	432	return NULL;
	433	}
	434	EXPORT_SYMBOL(scsi_host_alloc);
	435
	436	struct Scsi_Host scsi_register(struct scsi_host_template sht, int privsize)
	437	{
	438	struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
	439
	440	if (!sht->detect) {
	441	printk(KERN_WARNING "scsi_register() called on new-style "
	442	"template for driver %s\n", sht->name);
	443	dump_stack();
	444	}
	445
	446	if (shost)
	447	list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
	448	return shost;
	449	}
	450	EXPORT_SYMBOL(scsi_register);
	451
	452	void scsi_unregister(struct Scsi_Host *shost)
	453	{
	454	list_del(&shost->sht_legacy_list);
	455	scsi_host_put(shost);
	456	}
	457	EXPORT_SYMBOL(scsi_unregister);
	458
ee959b00	459	static int __scsi_host_match(struct device dev, void data)
9c770108 DY	460	{
	461	struct Scsi_Host *p;
	462	unsigned short hostnum = (unsigned short )data;
	463
ee959b00	464	p = class_to_shost(dev);
9c770108 DY	465	return p->host_no == *hostnum;
	466	}
	467
1da177e4 LT	468	/**
1da177e4 LT	469	* scsi_host_lookup - get a reference to a Scsi_Host by host no
1da177e4 LT	470	* @hostnum: host number to locate
	471	*
	472	* Return value:
	473	* A pointer to located Scsi_Host or NULL.
3ed78972 MC	474	*
	475	* The caller must do a scsi_host_put() to drop the reference
	476	* that scsi_host_get() took. The put_device() below dropped
	477	* the reference from class_find_device().
1da177e4 LT	478	**/
	479	struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
	480	{
ee959b00	481	struct device *cdev;
315cb0ad	482	struct Scsi_Host *shost = NULL;
1da177e4	483
695794ae GKH	484	cdev = class_find_device(&shost_class, NULL, &hostnum,
695794ae GKH	485	__scsi_host_match);
3ed78972	486	if (cdev) {
9c770108	487	shost = scsi_host_get(class_to_shost(cdev));
3ed78972 MC	488	put_device(cdev);
3ed78972 MC	489	}
1da177e4 LT	490	return shost;
	491	}
	492	EXPORT_SYMBOL(scsi_host_lookup);
	493
	494	/**
	495	* scsi_host_get - inc a Scsi_Host ref count
	496	* @shost: Pointer to Scsi_Host to inc.
	497	**/
	498	struct Scsi_Host scsi_host_get(struct Scsi_Host shost)
	499	{
d3301874	500	if ((shost->shost_state == SHOST_DEL) \|\|
1da177e4 LT	501	!get_device(&shost->shost_gendev))
	502	return NULL;
	503	return shost;
	504	}
	505	EXPORT_SYMBOL(scsi_host_get);
	506
	507	/**
	508	* scsi_host_put - dec a Scsi_Host ref count
	509	* @shost: Pointer to Scsi_Host to dec.
	510	**/
	511	void scsi_host_put(struct Scsi_Host *shost)
	512	{
	513	put_device(&shost->shost_gendev);
	514	}
	515	EXPORT_SYMBOL(scsi_host_put);
	516
	517	int scsi_init_hosts(void)
	518	{
	519	return class_register(&shost_class);
	520	}
	521
	522	void scsi_exit_hosts(void)
	523	{
	524	class_unregister(&shost_class);
	525	}
	526
	527	int scsi_is_host_device(const struct device *dev)
	528	{
b0ed4336	529	return dev->type == &scsi_host_type;
1da177e4 LT	530	}
	531	EXPORT_SYMBOL(scsi_is_host_device);
	532
	533	/**
	534	* scsi_queue_work - Queue work to the Scsi_Host workqueue.
	535	* @shost: Pointer to Scsi_Host.
	536	* @work: Work to queue for execution.
	537	*
	538	* Return value:
dd7e2f22 MR	539	* 1 - work queued for execution
	540	* 0 - work is already queued
	541	* -EINVAL - work queue doesn't exist
1da177e4 LT	542	**/
	543	int scsi_queue_work(struct Scsi_Host shost, struct work_struct work)
	544	{
	545	if (unlikely(!shost->work_q)) {
	546	printk(KERN_ERR
	547	"ERROR: Scsi host '%s' attempted to queue scsi-work, "
	548	"when no workqueue created.\n", shost->hostt->name);
	549	dump_stack();
	550
	551	return -EINVAL;
	552	}
	553
	554	return queue_work(shost->work_q, work);
	555	}
	556	EXPORT_SYMBOL_GPL(scsi_queue_work);
	557
	558	/**
	559	* scsi_flush_work - Flush a Scsi_Host's workqueue.
	560	* @shost: Pointer to Scsi_Host.
	561	**/
	562	void scsi_flush_work(struct Scsi_Host *shost)
	563	{
	564	if (!shost->work_q) {
	565	printk(KERN_ERR
	566	"ERROR: Scsi host '%s' attempted to flush scsi-work, "
	567	"when no workqueue created.\n", shost->hostt->name);
	568	dump_stack();
	569	return;
	570	}
	571
	572	flush_workqueue(shost->work_q);
	573	}
	574	EXPORT_SYMBOL_GPL(scsi_flush_work);