[linux.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
 *
 *  <[email protected]>
 *
 *  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 <[email protected]>
 *
 *  Restructured scsi_host lists and associated functions.
 *  September 04, 2002 Mike Anderson ([email protected])
 */

#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 <linux/pm_runtime.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_autopm_get_host(shost);
	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;

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

	pm_runtime_set_active(&shost->shost_gendev);
	pm_runtime_enable(&shost->shost_gendev);
	device_enable_async_suspend(&shost->shost_gendev);

	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;

	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->sg_prot_tablesize = sht->sg_prot_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);
	shost->shost_gendev.bus = &scsi_bus_type;
	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)) {
		printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
			shost->host_no, 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	* <[email protected]>
	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 <[email protected]>
	19	*
	20	* Restructured scsi_host lists and associated functions.
	21	* September 04, 2002 Mike Anderson ([email protected])
	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>
bc4f2401	35	#include <linux/pm_runtime.h>
1da177e4 LT	36
	37	#include <scsi/scsi_device.h>
	38	#include <scsi/scsi_host.h>
	39	#include <scsi/scsi_transport.h>
	40
	41	#include "scsi_priv.h"
	42	#include "scsi_logging.h"
	43
	44
30c9afa6	45	static atomic_t scsi_host_next_hn; /* host_no for next new host */
1da177e4 LT	46
1da177e4 LT	47
ee959b00	48	static void scsi_host_cls_release(struct device *dev)
1da177e4	49	{
ee959b00	50	put_device(&class_to_shost(dev)->shost_gendev);
1da177e4 LT	51	}
	52
	53	static struct class shost_class = {
	54	.name = "scsi_host",
ee959b00	55	.dev_release = scsi_host_cls_release,
1da177e4 LT	56	};
1da177e4 LT	57
d3301874	58	/**
eb44820c	59	* scsi_host_set_state - Take the given host through the host state model.
d3301874 MA	60	* @shost: scsi host to change the state of.
	61	* @state: state to change to.
	62	*
	63	* Returns zero if unsuccessful or an error if the requested
	64	* transition is illegal.
	65	**/
	66	int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
	67	{
	68	enum scsi_host_state oldstate = shost->shost_state;
	69
	70	if (state == oldstate)
	71	return 0;
	72
	73	switch (state) {
	74	case SHOST_CREATED:
	75	/* There are no legal states that come back to
	76	* created. This is the manually initialised start
	77	* state */
	78	goto illegal;
	79
	80	case SHOST_RUNNING:
	81	switch (oldstate) {
	82	case SHOST_CREATED:
	83	case SHOST_RECOVERY:
	84	break;
	85	default:
	86	goto illegal;
	87	}
	88	break;
	89
	90	case SHOST_RECOVERY:
	91	switch (oldstate) {
	92	case SHOST_RUNNING:
	93	break;
	94	default:
	95	goto illegal;
	96	}
	97	break;
	98
	99	case SHOST_CANCEL:
	100	switch (oldstate) {
	101	case SHOST_CREATED:
	102	case SHOST_RUNNING:
939647ee	103	case SHOST_CANCEL_RECOVERY:
d3301874 MA	104	break;
	105	default:
	106	goto illegal;
	107	}
	108	break;
	109
	110	case SHOST_DEL:
	111	switch (oldstate) {
	112	case SHOST_CANCEL:
939647ee	113	case SHOST_DEL_RECOVERY:
d3301874 MA	114	break;
	115	default:
	116	goto illegal;
	117	}
	118	break;
	119
939647ee JB	120	case SHOST_CANCEL_RECOVERY:
	121	switch (oldstate) {
	122	case SHOST_CANCEL:
	123	case SHOST_RECOVERY:
	124	break;
	125	default:
	126	goto illegal;
	127	}
	128	break;
	129
	130	case SHOST_DEL_RECOVERY:
	131	switch (oldstate) {
	132	case SHOST_CANCEL_RECOVERY:
	133	break;
	134	default:
	135	goto illegal;
	136	}
	137	break;
d3301874 MA	138	}
	139	shost->shost_state = state;
	140	return 0;
	141
	142	illegal:
	143	SCSI_LOG_ERROR_RECOVERY(1,
9ccfc756 JB	144	shost_printk(KERN_ERR, shost,
	145	"Illegal host state transition"
	146	"%s->%s\n",
	147	scsi_host_state_name(oldstate),
	148	scsi_host_state_name(state)));
d3301874 MA	149	return -EINVAL;
	150	}
	151	EXPORT_SYMBOL(scsi_host_set_state);
	152
1da177e4 LT	153	/**
	154	* scsi_remove_host - remove a scsi host
	155	* @shost: a pointer to a scsi host to remove
	156	**/
	157	void scsi_remove_host(struct Scsi_Host *shost)
	158	{
939647ee	159	unsigned long flags;
bc4f2401	160
0b950672	161	mutex_lock(&shost->scan_mutex);
939647ee JB	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);
0b950672	166	mutex_unlock(&shost->scan_mutex);
939647ee JB	167	return;
	168	}
	169	spin_unlock_irqrestore(shost->host_lock, flags);
bc4f2401 AS	170
bc4f2401 AS	171	scsi_autopm_get_host(shost);
1da177e4	172	scsi_forget_host(shost);
4e46bf89	173	mutex_unlock(&shost->scan_mutex);
1da177e4 LT	174	scsi_proc_host_rm(shost);
1da177e4 LT	175
939647ee JB	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);
1da177e4 LT	180
1da177e4 LT	181	transport_unregister_device(&shost->shost_gendev);
ee959b00	182	device_unregister(&shost->shost_dev);
1da177e4 LT	183	device_del(&shost->shost_gendev);
	184	}
	185	EXPORT_SYMBOL(scsi_remove_host);
	186
	187	/**
d139b9bd	188	* scsi_add_host_with_dma - add a scsi host with dma device
1da177e4 LT	189	* @shost: scsi host pointer to add
1da177e4 LT	190	* @dev: a struct device of type scsi class
d139b9bd JB	191	* @dma_dev: dma device for the host
	192	*
	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()
	195	* function instead.
1da177e4 LT	196	*
	197	* Return value:
	198	* 0 on success / != 0 for error
	199	**/
d139b9bd JB	200	int scsi_add_host_with_dma(struct Scsi_Host shost, struct device dev,
d139b9bd JB	201	struct device *dma_dev)
1da177e4 LT	202	{
	203	struct scsi_host_template *sht = shost->hostt;
	204	int error = -EINVAL;
	205
	206	printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
	207	sht->info ? sht->info(shost) : sht->name);
	208
	209	if (!shost->can_queue) {
	210	printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
	211	sht->name);
542bd137	212	goto fail;
1da177e4 LT	213	}
1da177e4 LT	214
542bd137 JB	215	error = scsi_setup_command_freelist(shost);
	216	if (error)
	217	goto fail;
	218
1da177e4 LT	219	if (!shost->shost_gendev.parent)
1da177e4 LT	220	shost->shost_gendev.parent = dev ? dev : &platform_bus;
d139b9bd	221	shost->dma_dev = dma_dev;
1da177e4 LT	222
	223	error = device_add(&shost->shost_gendev);
	224	if (error)
	225	goto out;
	226
bc4f2401 AS	227	pm_runtime_set_active(&shost->shost_gendev);
	228	pm_runtime_enable(&shost->shost_gendev);
	229	device_enable_async_suspend(&shost->shost_gendev);
	230
d3301874	231	scsi_host_set_state(shost, SHOST_RUNNING);
1da177e4 LT	232	get_device(shost->shost_gendev.parent);
1da177e4 LT	233
4cb077d9 RW	234	device_enable_async_suspend(&shost->shost_dev);
4cb077d9 RW	235
ee959b00	236	error = device_add(&shost->shost_dev);
1da177e4 LT	237	if (error)
	238	goto out_del_gendev;
	239
	240	get_device(&shost->shost_gendev);
	241
77cca462 JS	242	if (shost->transportt->host_size) {
	243	shost->shost_data = kzalloc(shost->transportt->host_size,
	244	GFP_KERNEL);
	245	if (shost->shost_data == NULL) {
	246	error = -ENOMEM;
ee959b00	247	goto out_del_dev;
77cca462 JS	248	}
77cca462 JS	249	}
1da177e4 LT	250
1da177e4 LT	251	if (shost->transportt->create_work_queue) {
aab0de24 KS	252	snprintf(shost->work_q_name, sizeof(shost->work_q_name),
aab0de24 KS	253	"scsi_wq_%d", shost->host_no);
1da177e4 LT	254	shost->work_q = create_singlethread_workqueue(
1da177e4 LT	255	shost->work_q_name);
77cca462 JS	256	if (!shost->work_q) {
77cca462 JS	257	error = -EINVAL;
1da177e4	258	goto out_free_shost_data;
77cca462	259	}
1da177e4 LT	260	}
	261
	262	error = scsi_sysfs_add_host(shost);
	263	if (error)
	264	goto out_destroy_host;
	265
	266	scsi_proc_host_add(shost);
	267	return error;
	268
	269	out_destroy_host:
	270	if (shost->work_q)
	271	destroy_workqueue(shost->work_q);
	272	out_free_shost_data:
	273	kfree(shost->shost_data);
ee959b00 TJ	274	out_del_dev:
ee959b00 TJ	275	device_del(&shost->shost_dev);
1da177e4 LT	276	out_del_gendev:
	277	device_del(&shost->shost_gendev);
	278	out:
542bd137 JB	279	scsi_destroy_command_freelist(shost);
542bd137 JB	280	fail:
1da177e4 LT	281	return error;
1da177e4 LT	282	}
d139b9bd	283	EXPORT_SYMBOL(scsi_add_host_with_dma);
1da177e4 LT	284
	285	static void scsi_host_dev_release(struct device *dev)
	286	{
	287	struct Scsi_Host *shost = dev_to_shost(dev);
	288	struct device *parent = dev->parent;
	289
77c01976 AS	290	scsi_proc_hostdir_rm(shost->hostt);
77c01976 AS	291
c5478def CH	292	if (shost->ehandler)
c5478def CH	293	kthread_stop(shost->ehandler);
1da177e4 LT	294	if (shost->work_q)
1da177e4 LT	295	destroy_workqueue(shost->work_q);
b58d9154 FT	296	if (shost->uspace_req_q) {
	297	kfree(shost->uspace_req_q->queuedata);
	298	scsi_free_queue(shost->uspace_req_q);
	299	}
1da177e4	300
1da177e4	301	scsi_destroy_command_freelist(shost);
86e33a29 JB	302	if (shost->bqt)
	303	blk_free_tags(shost->bqt);
	304
1da177e4 LT	305	kfree(shost->shost_data);
1da177e4 LT	306
1da177e4 LT	307	if (parent)
	308	put_device(parent);
	309	kfree(shost);
	310	}
	311
453cd0f3	312	static struct device_type scsi_host_type = {
b0ed4336 HR	313	.name = "scsi_host",
	314	.release = scsi_host_dev_release,
	315	};
	316
1da177e4 LT	317	/**
	318	* scsi_host_alloc - register a scsi host adapter instance.
	319	* @sht: pointer to scsi host template
	320	* @privsize: extra bytes to allocate for driver
	321	*
	322	* Note:
	323	* Allocate a new Scsi_Host and perform basic initialization.
	324	* The host is not published to the scsi midlayer until scsi_add_host
	325	* is called.
	326	*
	327	* Return value:
	328	* Pointer to a new Scsi_Host
	329	**/
	330	struct Scsi_Host scsi_host_alloc(struct scsi_host_template sht, int privsize)
	331	{
	332	struct Scsi_Host *shost;
c53033f6	333	gfp_t gfp_mask = GFP_KERNEL;
1da177e4 LT	334
	335	if (sht->unchecked_isa_dma && privsize)
	336	gfp_mask \|= __GFP_DMA;
	337
24669f75	338	shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
1da177e4 LT	339	if (!shost)
1da177e4 LT	340	return NULL;
1da177e4	341
4f777ed2 CH	342	shost->host_lock = &shost->default_lock;
4f777ed2 CH	343	spin_lock_init(shost->host_lock);
d3301874	344	shost->shost_state = SHOST_CREATED;
1da177e4 LT	345	INIT_LIST_HEAD(&shost->__devices);
	346	INIT_LIST_HEAD(&shost->__targets);
	347	INIT_LIST_HEAD(&shost->eh_cmd_q);
	348	INIT_LIST_HEAD(&shost->starved_list);
	349	init_waitqueue_head(&shost->host_wait);
	350
0b950672	351	mutex_init(&shost->scan_mutex);
1da177e4	352
30c9afa6 JE	353	/*
	354	* subtract one because we increment first then return, but we need to
	355	* know what the next host number was before increment
	356	*/
	357	shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
1da177e4 LT	358	shost->dma_channel = 0xff;
	359
	360	/* These three are default values which can be overridden */
	361	shost->max_channel = 0;
	362	shost->max_id = 8;
	363	shost->max_lun = 8;
	364
	365	/* Give each shost a default transportt */
	366	shost->transportt = &blank_transport_template;
	367
	368	/*
	369	* All drivers right now should be able to handle 12 byte
	370	* commands. Every so often there are requests for 16 byte
	371	* commands, but individual low-level drivers need to certify that
	372	* they actually do something sensible with such commands.
	373	*/
	374	shost->max_cmd_len = 12;
	375	shost->hostt = sht;
	376	shost->this_id = sht->this_id;
	377	shost->can_queue = sht->can_queue;
	378	shost->sg_tablesize = sht->sg_tablesize;
13f05c8d	379	shost->sg_prot_tablesize = sht->sg_prot_tablesize;
1da177e4 LT	380	shost->cmd_per_lun = sht->cmd_per_lun;
	381	shost->unchecked_isa_dma = sht->unchecked_isa_dma;
	382	shost->use_clustering = sht->use_clustering;
1da177e4 LT	383	shost->ordered_tag = sht->ordered_tag;
1da177e4 LT	384
7a39ac3f JB	385	if (sht->supported_mode == MODE_UNKNOWN)
	386	/* means we didn't set it ... default to INITIATOR */
	387	shost->active_mode = MODE_INITIATOR;
	388	else
	389	shost->active_mode = sht->supported_mode;
	390
1da177e4 LT	391	if (sht->max_host_blocked)
	392	shost->max_host_blocked = sht->max_host_blocked;
	393	else
	394	shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
	395
	396	/*
	397	* If the driver imposes no hard sector transfer limit, start at
	398	* machine infinity initially.
	399	*/
	400	if (sht->max_sectors)
	401	shost->max_sectors = sht->max_sectors;
	402	else
	403	shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
	404
	405	/*
	406	* assume a 4GB boundary, if not set
	407	*/
	408	if (sht->dma_boundary)
	409	shost->dma_boundary = sht->dma_boundary;
	410	else
	411	shost->dma_boundary = 0xffffffff;
	412
1da177e4	413	device_initialize(&shost->shost_gendev);
71610f55	414	dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
b0ed4336	415	shost->shost_gendev.bus = &scsi_bus_type;
b0ed4336	416	shost->shost_gendev.type = &scsi_host_type;
1da177e4	417
ee959b00 TJ	418	device_initialize(&shost->shost_dev);
	419	shost->shost_dev.parent = &shost->shost_gendev;
	420	shost->shost_dev.class = &shost_class;
71610f55	421	dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
f7120a4f	422	shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
1da177e4	423
c5478def CH	424	shost->ehandler = kthread_run(scsi_error_handler, shost,
	425	"scsi_eh_%d", shost->host_no);
	426	if (IS_ERR(shost->ehandler)) {
e4bf25fb JM	427	printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n",
e4bf25fb JM	428	shost->host_no, PTR_ERR(shost->ehandler));
542bd137	429	goto fail_kfree;
c5478def	430	}
1da177e4 LT	431
	432	scsi_proc_hostdir_add(shost->hostt);
	433	return shost;
	434
1da177e4 LT	435	fail_kfree:
	436	kfree(shost);
	437	return NULL;
	438	}
	439	EXPORT_SYMBOL(scsi_host_alloc);
	440
	441	struct Scsi_Host scsi_register(struct scsi_host_template sht, int privsize)
	442	{
	443	struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
	444
	445	if (!sht->detect) {
	446	printk(KERN_WARNING "scsi_register() called on new-style "
	447	"template for driver %s\n", sht->name);
	448	dump_stack();
	449	}
	450
	451	if (shost)
	452	list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
	453	return shost;
	454	}
	455	EXPORT_SYMBOL(scsi_register);
	456
	457	void scsi_unregister(struct Scsi_Host *shost)
	458	{
	459	list_del(&shost->sht_legacy_list);
	460	scsi_host_put(shost);
	461	}
	462	EXPORT_SYMBOL(scsi_unregister);
	463
ee959b00	464	static int __scsi_host_match(struct device dev, void data)
9c770108 DY	465	{
	466	struct Scsi_Host *p;
	467	unsigned short hostnum = (unsigned short )data;
	468
ee959b00	469	p = class_to_shost(dev);
9c770108 DY	470	return p->host_no == *hostnum;
	471	}
	472
1da177e4 LT	473	/**
1da177e4 LT	474	* scsi_host_lookup - get a reference to a Scsi_Host by host no
1da177e4 LT	475	* @hostnum: host number to locate
	476	*
	477	* Return value:
	478	* A pointer to located Scsi_Host or NULL.
3ed78972 MC	479	*
	480	* The caller must do a scsi_host_put() to drop the reference
	481	* that scsi_host_get() took. The put_device() below dropped
	482	* the reference from class_find_device().
1da177e4 LT	483	**/
	484	struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
	485	{
ee959b00	486	struct device *cdev;
315cb0ad	487	struct Scsi_Host *shost = NULL;
1da177e4	488
695794ae GKH	489	cdev = class_find_device(&shost_class, NULL, &hostnum,
695794ae GKH	490	__scsi_host_match);
3ed78972	491	if (cdev) {
9c770108	492	shost = scsi_host_get(class_to_shost(cdev));
3ed78972 MC	493	put_device(cdev);
3ed78972 MC	494	}
1da177e4 LT	495	return shost;
	496	}
	497	EXPORT_SYMBOL(scsi_host_lookup);
	498
	499	/**
	500	* scsi_host_get - inc a Scsi_Host ref count
	501	* @shost: Pointer to Scsi_Host to inc.
	502	**/
	503	struct Scsi_Host scsi_host_get(struct Scsi_Host shost)
	504	{
d3301874	505	if ((shost->shost_state == SHOST_DEL) \|\|
1da177e4 LT	506	!get_device(&shost->shost_gendev))
	507	return NULL;
	508	return shost;
	509	}
	510	EXPORT_SYMBOL(scsi_host_get);
	511
	512	/**
	513	* scsi_host_put - dec a Scsi_Host ref count
	514	* @shost: Pointer to Scsi_Host to dec.
	515	**/
	516	void scsi_host_put(struct Scsi_Host *shost)
	517	{
	518	put_device(&shost->shost_gendev);
	519	}
	520	EXPORT_SYMBOL(scsi_host_put);
	521
	522	int scsi_init_hosts(void)
	523	{
	524	return class_register(&shost_class);
	525	}
	526
	527	void scsi_exit_hosts(void)
	528	{
	529	class_unregister(&shost_class);
	530	}
	531
	532	int scsi_is_host_device(const struct device *dev)
	533	{
b0ed4336	534	return dev->type == &scsi_host_type;
1da177e4 LT	535	}
	536	EXPORT_SYMBOL(scsi_is_host_device);
	537
	538	/**
	539	* scsi_queue_work - Queue work to the Scsi_Host workqueue.
	540	* @shost: Pointer to Scsi_Host.
	541	* @work: Work to queue for execution.
	542	*
	543	* Return value:
dd7e2f22 MR	544	* 1 - work queued for execution
	545	* 0 - work is already queued
	546	* -EINVAL - work queue doesn't exist
1da177e4 LT	547	**/
	548	int scsi_queue_work(struct Scsi_Host shost, struct work_struct work)
	549	{
	550	if (unlikely(!shost->work_q)) {
	551	printk(KERN_ERR
	552	"ERROR: Scsi host '%s' attempted to queue scsi-work, "
	553	"when no workqueue created.\n", shost->hostt->name);
	554	dump_stack();
	555
	556	return -EINVAL;
	557	}
	558
	559	return queue_work(shost->work_q, work);
	560	}
	561	EXPORT_SYMBOL_GPL(scsi_queue_work);
	562
	563	/**
	564	* scsi_flush_work - Flush a Scsi_Host's workqueue.
	565	* @shost: Pointer to Scsi_Host.
	566	**/
	567	void scsi_flush_work(struct Scsi_Host *shost)
	568	{
	569	if (!shost->work_q) {
	570	printk(KERN_ERR
	571	"ERROR: Scsi host '%s' attempted to flush scsi-work, "
	572	"when no workqueue created.\n", shost->hostt->name);
	573	dump_stack();
	574	return;
	575	}
	576
	577	flush_workqueue(shost->work_q);
	578	}
	579	EXPORT_SYMBOL_GPL(scsi_flush_work);