text: /*
   * Copyright (C) 2005-2006 Dell Inc.
   *	Released under GPL v2.
   *
   * Serial Attached SCSI (SAS) transport class.
   *
   * The SAS transport class contains common code to deal with SAS HBAs,
   * an aproximated representation of SAS topologies in the driver model,
   * and various sysfs attributes to expose these topologies and management
   * interfaces to userspace.
   *
   * In addition to the basic SCSI core objects this transport class
   * introduces two additional intermediate objects:  The SAS PHY
   * as represented by struct sas_phy defines an "outgoing" PHY on
   * a SAS HBA or Expander, and the SAS remote PHY represented by
   * struct sas_rphy defines an "incoming" PHY on a SAS Expander or
   * end device.  Note that this is purely a software concept, the
   * underlying hardware for a PHY and a remote PHY is the exactly
   * the same.
   *
   * There is no concept of a SAS port in this code, users can see
   * what PHYs form a wide port based on the port_identifier attribute,
   * which is the same for all PHYs in a port.
   */
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/jiffies.h>
  #include <linux/err.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/blkdev.h>
  #include <linux/bsg.h>
  
  #include <scsi/scsi.h>
  #include <scsi/scsi_request.h>
  #include <scsi/scsi_device.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_transport.h>
  #include <scsi/scsi_transport_sas.h>
  
  #include "scsi_sas_internal.h"
  struct sas_host_attrs {
  	struct list_head rphy_list;
  	struct mutex lock;
  	struct request_queue *q;
  	u32 next_target_id;
  	u32 next_expander_id;
  	int next_port_id;
  };
  #define to_sas_host_attrs(host)	((struct sas_host_attrs *)(host)->shost_data)
  
  
  /*
   * Hack to allow attributes of the same name in different objects.
   */
  #define SAS_DEVICE_ATTR(_prefix,_name,_mode,_show,_store) \
  	struct device_attribute dev_attr_##_prefix##_##_name = \
  	__ATTR(_name,_mode,_show,_store)
  
  
  /*
   * Pretty printing helpers
   */
  
  #define sas_bitfield_name_match(title, table)			\
  static ssize_t							\
  get_sas_##title##_names(u32 table_key, char *buf)		\
  {								\
  	char *prefix = "";					\
  	ssize_t len = 0;					\
  	int i;							\
  								\
  	for (i = 0; i < ARRAY_SIZE(table); i++) {		\
  		if (table[i].value & table_key) {		\
  			len += sprintf(buf + len, "%s%s",	\
  				prefix, table[i].name);		\
  			prefix = ", ";				\
  		}						\
  	}							\
  	len += sprintf(buf + len, "\n");			\
  	return len;						\
  }
  
  #define sas_bitfield_name_set(title, table)			\
  static ssize_t							\
  set_sas_##title##_names(u32 *table_key, const char *buf)	\
  {								\
  	ssize_t len = 0;					\
  	int i;							\
  								\
  	for (i = 0; i < ARRAY_SIZE(table); i++) {		\
  		len = strlen(table[i].name);			\
  		if (strncmp(buf, table[i].name, len) == 0 &&	\
  		    (buf[len] == '\n' || buf[len] == '\0')) {	\
  			*table_key = table[i].value;		\
  			return 0;				\
  		}						\
  	}							\
  	return -EINVAL;						\
  }
  
  #define sas_bitfield_name_search(title, table)			\
  static ssize_t							\
  get_sas_##title##_names(u32 table_key, char *buf)		\
  {								\
  	ssize_t len = 0;					\
  	int i;							\
  								\
  	for (i = 0; i < ARRAY_SIZE(table); i++) {		\
  		if (table[i].value == table_key) {		\
  			len += sprintf(buf + len, "%s",		\
  				table[i].name);			\
  			break;					\
  		}						\
  	}							\
  	len += sprintf(buf + len, "\n");			\
  	return len;						\
  }
  
  static struct {
  	u32		value;
  	char		*name;
  } sas_device_type_names[] = {
  	{ SAS_PHY_UNUSED,		"unused" },
  	{ SAS_END_DEVICE,		"end device" },
  	{ SAS_EDGE_EXPANDER_DEVICE,	"edge expander" },
  	{ SAS_FANOUT_EXPANDER_DEVICE,	"fanout expander" },
  };
  sas_bitfield_name_search(device_type, sas_device_type_names)
  
  
  static struct {
  	u32		value;
  	char		*name;
  } sas_protocol_names[] = {
  	{ SAS_PROTOCOL_SATA,		"sata" },
  	{ SAS_PROTOCOL_SMP,		"smp" },
  	{ SAS_PROTOCOL_STP,		"stp" },
  	{ SAS_PROTOCOL_SSP,		"ssp" },
  };
  sas_bitfield_name_match(protocol, sas_protocol_names)
  
  static struct {
  	u32		value;
  	char		*name;
  } sas_linkspeed_names[] = {
  	{ SAS_LINK_RATE_UNKNOWN,	"Unknown" },
  	{ SAS_PHY_DISABLED,		"Phy disabled" },
  	{ SAS_LINK_RATE_FAILED,		"Link Rate failed" },
  	{ SAS_SATA_SPINUP_HOLD,		"Spin-up hold" },
  	{ SAS_LINK_RATE_1_5_GBPS,	"1.5 Gbit" },
  	{ SAS_LINK_RATE_3_0_GBPS,	"3.0 Gbit" },
  	{ SAS_LINK_RATE_6_0_GBPS,	"6.0 Gbit" },
  	{ SAS_LINK_RATE_12_0_GBPS,	"12.0 Gbit" },
  };
  sas_bitfield_name_search(linkspeed, sas_linkspeed_names)
  sas_bitfield_name_set(linkspeed, sas_linkspeed_names)
  
  static struct sas_end_device *sas_sdev_to_rdev(struct scsi_device *sdev)
  {
  	struct sas_rphy *rphy = target_to_rphy(sdev->sdev_target);
  	struct sas_end_device *rdev;
  
  	BUG_ON(rphy->identify.device_type != SAS_END_DEVICE);
  
  	rdev = rphy_to_end_device(rphy);
  	return rdev;
  }
  
  static void sas_smp_request(struct request_queue *q, struct Scsi_Host *shost,
  			    struct sas_rphy *rphy)
  {
  	struct request *req;
  	int ret;
  	int (*handler)(struct Scsi_Host *, struct sas_rphy *, struct request *);
  
  	while ((req = blk_fetch_request(q)) != NULL) {
  		spin_unlock_irq(q->queue_lock);
  
  		scsi_req(req)->resid_len = blk_rq_bytes(req);
  		if (req->next_rq)
  			scsi_req(req->next_rq)->resid_len =
  				blk_rq_bytes(req->next_rq);
  		handler = to_sas_internal(shost->transportt)->f->smp_handler;
  		ret = handler(shost, rphy, req);
  		req->errors = ret;
  
  		blk_end_request_all(req, ret);
  
  		spin_lock_irq(q->queue_lock);
  	}
  }
  
  static void sas_host_smp_request(struct request_queue *q)
  {
  	sas_smp_request(q, (struct Scsi_Host *)q->queuedata, NULL);
  }
  
  static void sas_non_host_smp_request(struct request_queue *q)
  {
  	struct sas_rphy *rphy = q->queuedata;
  	sas_smp_request(q, rphy_to_shost(rphy), rphy);
  }
  
  static void sas_host_release(struct device *dev)
  {
  	struct Scsi_Host *shost = dev_to_shost(dev);
  	struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
  	struct request_queue *q = sas_host->q;
  
  	if (q)
  		blk_cleanup_queue(q);
  }
  
  static int sas_bsg_initialize(struct Scsi_Host *shost, struct sas_rphy *rphy)
  {
  	struct request_queue *q;
  	int error;
  	struct device *dev;
  	char namebuf[20];
  	const char *name;
  	void (*release)(struct device *);
  
  	if (!to_sas_internal(shost->transportt)->f->smp_handler) {
  		printk("%s can't handle SMP requests\n", shost->hostt->name);
  		return 0;
  	}
  
  	q = blk_alloc_queue(GFP_KERNEL);
  	if (!q)
  		return -ENOMEM;
  	q->cmd_size = sizeof(struct scsi_request);
  
  	if (rphy) {
  		q->request_fn = sas_non_host_smp_request;
  		dev = &rphy->dev;
  		name = dev_name(dev);
  		release = NULL;
  	} else {
  		q->request_fn = sas_host_smp_request;
  		dev = &shost->shost_gendev;
  		snprintf(namebuf, sizeof(namebuf),
  			 "sas_host%d", shost->host_no);
  		name = namebuf;
  		release = sas_host_release;
  	}
  	error = blk_init_allocated_queue(q);
  	if (error)
  		goto out_cleanup_queue;
  
  	error = bsg_register_queue(q, dev, name, release);
  	if (error)
  		goto out_cleanup_queue;
  
  	if (rphy)
  		rphy->q = q;
  	else
  		to_sas_host_attrs(shost)->q = q;
  
  	if (rphy)
  		q->queuedata = rphy;
  	else
  		q->queuedata = shost;
  
  	queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
  	return 0;
  
  out_cleanup_queue:
  	blk_cleanup_queue(q);
  	return error;
  }
  
  static void sas_bsg_remove(struct Scsi_Host *shost, struct sas_rphy *rphy)
  {
  	struct request_queue *q;
  
  	if (rphy)
  		q = rphy->q;
  	else
  		q = to_sas_host_attrs(shost)->q;
  
  	if (!q)
  		return;
  
  	bsg_unregister_queue(q);
  }
  
  /*
   * SAS host attributes
   */
  
  static int sas_host_setup(struct transport_container *tc, struct device *dev,
  			  struct device *cdev)
  {
  	struct Scsi_Host *shost = dev_to_shost(dev);
  	struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
  
  	INIT_LIST_HEAD(&sas_host->rphy_list);
  	mutex_init(&sas_host->lock);
  	sas_host->next_target_id = 0;
  	sas_host->next_expander_id = 0;
  	sas_host->next_port_id = 0;
  
  	if (sas_bsg_initialize(shost, NULL))
  		dev_printk(KERN_ERR, dev, "fail to a bsg device %d\n",
  			   shost->host_no);
  
  	return 0;
  }
  
  static int sas_host_remove(struct transport_container *tc, struct device *dev,
  			   struct device *cdev)
  {
  	struct Scsi_Host *shost = dev_to_shost(dev);
  
  	sas_bsg_remove(shost, NULL);
  
  	return 0;
  }
  
  static DECLARE_TRANSPORT_CLASS(sas_host_class,
  		"sas_host", sas_host_setup, sas_host_remove, NULL);
  
  static int sas_host_match(struct attribute_container *cont,
  			    struct device *dev)
  {
  	struct Scsi_Host *shost;
  	struct sas_internal *i;
  
  	if (!scsi_is_host_device(dev))
  		return 0;
  	shost = dev_to_shost(dev);
  
  	if (!shost->transportt)
  		return 0;
  	if (shost->transportt->host_attrs.ac.class !=
  			&sas_host_class.class)
  		return 0;
  
  	i = to_sas_internal(shost->transportt);
  	return &i->t.host_attrs.ac == cont;
  }
  
  static int do_sas_phy_delete(struct device *dev, void *data)
  {
  	int pass = (int)(unsigned long)data;
  
  	if (pass == 0 && scsi_is_sas_port(dev))
  		sas_port_delete(dev_to_sas_port(dev));
  	else if (pass == 1 && scsi_is_sas_phy(dev))
  		sas_phy_delete(dev_to_phy(dev));
  	return 0;
  }
  
  /**
   * sas_remove_children  -  tear down a devices SAS data structures
   * @dev:	device belonging to the sas object
   *
   * Removes all SAS PHYs and remote PHYs for a given object
   */
  void sas_remove_children(struct device *dev)
  {
  	device_for_each_child(dev, (void *)0, do_sas_phy_delete);
  	device_for_each_child(dev, (void *)1, do_sas_phy_delete);
  }
  EXPORT_SYMBOL(sas_remove_children);
  
  /**
   * sas_remove_host  -  tear down a Scsi_Host's SAS data structures
   * @shost:	Scsi Host that is torn down
   *
   * Removes all SAS PHYs and remote PHYs for a given Scsi_Host.
   * Must be called just before scsi_remove_host for SAS HBAs.
   */
  void sas_remove_host(struct Scsi_Host *shost)
  {
  	sas_remove_children(&shost->shost_gendev);
  }
  EXPORT_SYMBOL(sas_remove_host);
  
  /**
   * sas_get_address - return the SAS address of the device
   * @sdev: scsi device
   *
   * Returns the SAS address of the scsi device
   */
  u64 sas_get_address(struct scsi_device *sdev)
  {
  	struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
  
  	return rdev->rphy.identify.sas_address;
  }
  EXPORT_SYMBOL(sas_get_address);
  
  /**
   * sas_tlr_supported - checking TLR bit in vpd 0x90
   * @sdev: scsi device struct
   *
   * Check Transport Layer Retries are supported or not.
   * If vpd page 0x90 is present, TRL is supported.
   *
   */
  unsigned int
  sas_tlr_supported(struct scsi_device *sdev)
  {
  	const int vpd_len = 32;
  	struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
  	char *buffer = kzalloc(vpd_len, GFP_KERNEL);
  	int ret = 0;
  
  	if (scsi_get_vpd_page(sdev, 0x90, buffer, vpd_len))
  		goto out;
  
  	/*
  	 * Magic numbers: the VPD Protocol page (0x90)
  	 * has a 4 byte header and then one entry per device port
  	 * the TLR bit is at offset 8 on each port entry
  	 * if we take the first port, that's at total offset 12
  	 */
  	ret = buffer[12] & 0x01;
  
   out:
  	kfree(buffer);
  	rdev->tlr_supported = ret;
  	return ret;
  
  }
  EXPORT_SYMBOL_GPL(sas_tlr_supported);
  
  /**
   * sas_disable_tlr - setting TLR flags
   * @sdev: scsi device struct
   *
   * Seting tlr_enabled flag to 0.
   *
   */
  void
  sas_disable_tlr(struct scsi_device *sdev)
  {
  	struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
  
  	rdev->tlr_enabled = 0;
  }
  EXPORT_SYMBOL_GPL(sas_disable_tlr);
  
  /**
   * sas_enable_tlr - setting TLR flags
   * @sdev: scsi device struct
   *
   * Seting tlr_enabled flag 1.
   *
   */
  void sas_enable_tlr(struct scsi_device *sdev)
  {
  	unsigned int tlr_supported = 0;
  	tlr_supported  = sas_tlr_supported(sdev);
  
  	if (tlr_supported) {
  		struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
  
  		rdev->tlr_enabled = 1;
  	}
  
  	return;
  }
  EXPORT_SYMBOL_GPL(sas_enable_tlr);
  
  unsigned int sas_is_tlr_enabled(struct scsi_device *sdev)
  {
  	struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
  	return rdev->tlr_enabled;
  }
  EXPORT_SYMBOL_GPL(sas_is_tlr_enabled);
  
  /*
   * SAS Phy attributes
   */
  
  #define sas_phy_show_simple(field, name, format_string, cast)		\
  static ssize_t								\
  show_sas_phy_##name(struct device *dev, 				\
  		    struct device_attribute *attr, char *buf)		\
  {									\
  	struct sas_phy *phy = transport_class_to_phy(dev);		\
  									\
  	return snprintf(buf, 20, format_string, cast phy->field);	\
  }
  
  #define sas_phy_simple_attr(field, name, format_string, type)		\
  	sas_phy_show_simple(field, name, format_string, (type))	\
  static DEVICE_ATTR(name, S_IRUGO, show_sas_phy_##name, NULL)
  
  #define sas_phy_show_protocol(field, name)				\
  static ssize_t								\
  show_sas_phy_##name(struct device *dev, 				\
  		    struct device_attribute *attr, char *buf)		\
  {									\
  	struct sas_phy *phy = transport_class_to_phy(dev);		\
  									\
  	if (!phy->field)						\
  		return snprintf(buf, 20, "none\n");			\
  	return get_sas_protocol_names(phy->field, buf);		\
  }
  
  #define sas_phy_protocol_attr(field, name)				\
  	sas_phy_show_protocol(field, name)				\
  static DEVICE_ATTR(name, S_IRUGO, show_sas_phy_##name, NULL)
  
  #define sas_phy_show_linkspeed(field)					\
  static ssize_t								\
  show_sas_phy_##field(struct device *dev, 				\
  		     struct device_attribute *attr, char *buf)		\
  {									\
  	struct sas_phy *phy = transport_class_to_phy(dev);		\
  									\
  	return get_sas_linkspeed_names(phy->field, buf);		\
  }
  
  /* Fudge to tell if we're minimum or maximum */
  #define sas_phy_store_linkspeed(field)					\
  static ssize_t								\
  store_sas_phy_##field(struct device *dev, 				\
  		      struct device_attribute *attr, 			\
  		      const char *buf,	size_t count)			\
  {									\
  	struct sas_phy *phy = transport_class_to_phy(dev);		\
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);	\
  	struct sas_internal *i = to_sas_internal(shost->transportt);	\
  	u32 value;							\
  	struct sas_phy_linkrates rates = {0};				\
  	int error;							\
  									\
  	error = set_sas_linkspeed_names(&value, buf);			\
  	if (error)							\
  		return error;						\
  	rates.field = value;						\
  	error = i->f->set_phy_speed(phy, &rates);			\
  									\
  	return error ? error : count;					\
  }
  
  #define sas_phy_linkspeed_rw_attr(field)				\
  	sas_phy_show_linkspeed(field)					\
  	sas_phy_store_linkspeed(field)					\
  static DEVICE_ATTR(field, S_IRUGO, show_sas_phy_##field,		\
  	store_sas_phy_##field)
  
  #define sas_phy_linkspeed_attr(field)					\
  	sas_phy_show_linkspeed(field)					\
  static DEVICE_ATTR(field, S_IRUGO, show_sas_phy_##field, NULL)
  
  
  #define sas_phy_show_linkerror(field)					\
  static ssize_t								\
  show_sas_phy_##field(struct device *dev, 				\
  		     struct device_attribute *attr, char *buf)		\
  {									\
  	struct sas_phy *phy = transport_class_to_phy(dev);		\
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);	\
  	struct sas_internal *i = to_sas_internal(shost->transportt);	\
  	int error;							\
  									\
  	error = i->f->get_linkerrors ? i->f->get_linkerrors(phy) : 0;	\
  	if (error)							\
  		return error;						\
  	return snprintf(buf, 20, "%u\n", phy->field);			\
  }
  
  #define sas_phy_linkerror_attr(field)					\
  	sas_phy_show_linkerror(field)					\
  static DEVICE_ATTR(field, S_IRUGO, show_sas_phy_##field, NULL)
  
  
  static ssize_t
  show_sas_device_type(struct device *dev,
  		     struct device_attribute *attr, char *buf)
  {
  	struct sas_phy *phy = transport_class_to_phy(dev);
  
  	if (!phy->identify.device_type)
  		return snprintf(buf, 20, "none\n");
  	return get_sas_device_type_names(phy->identify.device_type, buf);
  }
  static DEVICE_ATTR(device_type, S_IRUGO, show_sas_device_type, NULL);
  
  static ssize_t do_sas_phy_enable(struct device *dev,
  		size_t count, int enable)
  {
  	struct sas_phy *phy = transport_class_to_phy(dev);
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
  	struct sas_internal *i = to_sas_internal(shost->transportt);
  	int error;
  
  	error = i->f->phy_enable(phy, enable);
  	if (error)
  		return error;
  	phy->enabled = enable;
  	return count;
  };
  
  static ssize_t
  store_sas_phy_enable(struct device *dev, struct device_attribute *attr,
  		     const char *buf, size_t count)
  {
  	if (count < 1)
  		return -EINVAL;
  
  	switch (buf[0]) {
  	case '0':
  		do_sas_phy_enable(dev, count, 0);
  		break;
  	case '1':
  		do_sas_phy_enable(dev, count, 1);
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	return count;
  }
  
  static ssize_t
  show_sas_phy_enable(struct device *dev, struct device_attribute *attr,
  		    char *buf)
  {
  	struct sas_phy *phy = transport_class_to_phy(dev);
  
  	return snprintf(buf, 20, "%d", phy->enabled);
  }
  
  static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR, show_sas_phy_enable,
  			 store_sas_phy_enable);
  
  static ssize_t
  do_sas_phy_reset(struct device *dev, size_t count, int hard_reset)
  {
  	struct sas_phy *phy = transport_class_to_phy(dev);
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
  	struct sas_internal *i = to_sas_internal(shost->transportt);
  	int error;
  
  	error = i->f->phy_reset(phy, hard_reset);
  	if (error)
  		return error;
  	phy->enabled = 1;
  	return count;
  };
  
  static ssize_t
  store_sas_link_reset(struct device *dev, struct device_attribute *attr,
  		     const char *buf, size_t count)
  {
  	return do_sas_phy_reset(dev, count, 0);
  }
  static DEVICE_ATTR(link_reset, S_IWUSR, NULL, store_sas_link_reset);
  
  static ssize_t
  store_sas_hard_reset(struct device *dev, struct device_attribute *attr,
  		     const char *buf, size_t count)
  {
  	return do_sas_phy_reset(dev, count, 1);
  }
  static DEVICE_ATTR(hard_reset, S_IWUSR, NULL, store_sas_hard_reset);
  
  sas_phy_protocol_attr(identify.initiator_port_protocols,
  		initiator_port_protocols);
  sas_phy_protocol_attr(identify.target_port_protocols,
  		target_port_protocols);
  sas_phy_simple_attr(identify.sas_address, sas_address, "0x%016llx\n",
  		unsigned long long);
  sas_phy_simple_attr(identify.phy_identifier, phy_identifier, "%d\n", u8);
  //sas_phy_simple_attr(port_identifier, port_identifier, "%d\n", int);
  sas_phy_linkspeed_attr(negotiated_linkrate);
  sas_phy_linkspeed_attr(minimum_linkrate_hw);
  sas_phy_linkspeed_rw_attr(minimum_linkrate);
  sas_phy_linkspeed_attr(maximum_linkrate_hw);
  sas_phy_linkspeed_rw_attr(maximum_linkrate);
  sas_phy_linkerror_attr(invalid_dword_count);
  sas_phy_linkerror_attr(running_disparity_error_count);
  sas_phy_linkerror_attr(loss_of_dword_sync_count);
  sas_phy_linkerror_attr(phy_reset_problem_count);
  
  static int sas_phy_setup(struct transport_container *tc, struct device *dev,
  			 struct device *cdev)
  {
  	struct sas_phy *phy = dev_to_phy(dev);
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
  	struct sas_internal *i = to_sas_internal(shost->transportt);
  
  	if (i->f->phy_setup)
  		i->f->phy_setup(phy);
  
  	return 0;
  }
  
  static DECLARE_TRANSPORT_CLASS(sas_phy_class,
  		"sas_phy", sas_phy_setup, NULL, NULL);
  
  static int sas_phy_match(struct attribute_container *cont, struct device *dev)
  {
  	struct Scsi_Host *shost;
  	struct sas_internal *i;
  
  	if (!scsi_is_sas_phy(dev))
  		return 0;
  	shost = dev_to_shost(dev->parent);
  
  	if (!shost->transportt)
  		return 0;
  	if (shost->transportt->host_attrs.ac.class !=
  			&sas_host_class.class)
  		return 0;
  
  	i = to_sas_internal(shost->transportt);
  	return &i->phy_attr_cont.ac == cont;
  }
  
  static void sas_phy_release(struct device *dev)
  {
  	struct sas_phy *phy = dev_to_phy(dev);
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
  	struct sas_internal *i = to_sas_internal(shost->transportt);
  
  	if (i->f->phy_release)
  		i->f->phy_release(phy);
  	put_device(dev->parent);
  	kfree(phy);
  }
  
  /**
   * sas_phy_alloc  -  allocates and initialize a SAS PHY structure
   * @parent:	Parent device
   * @number:	Phy index
   *
   * Allocates an SAS PHY structure.  It will be added in the device tree
   * below the device specified by @parent, which has to be either a Scsi_Host
   * or sas_rphy.
   *
   * Returns:
   *	SAS PHY allocated or %NULL if the allocation failed.
   */
  struct sas_phy *sas_phy_alloc(struct device *parent, int number)
  {
  	struct Scsi_Host *shost = dev_to_shost(parent);
  	struct sas_phy *phy;
  
  	phy = kzalloc(sizeof(*phy), GFP_KERNEL);
  	if (!phy)
  		return NULL;
  
  	phy->number = number;
  	phy->enabled = 1;
  
  	device_initialize(&phy->dev);
  	phy->dev.parent = get_device(parent);
  	phy->dev.release = sas_phy_release;
  	INIT_LIST_HEAD(&phy->port_siblings);
  	if (scsi_is_sas_expander_device(parent)) {
  		struct sas_rphy *rphy = dev_to_rphy(parent);
  		dev_set_name(&phy->dev, "phy-%d:%d:%d", shost->host_no,
  			rphy->scsi_target_id, number);
  	} else
  		dev_set_name(&phy->dev, "phy-%d:%d", shost->host_no, number);
  
  	transport_setup_device(&phy->dev);
  
  	return phy;
  }
  EXPORT_SYMBOL(sas_phy_alloc);
  
  /**
   * sas_phy_add  -  add a SAS PHY to the device hierarchy
   * @phy:	The PHY to be added
   *
   * Publishes a SAS PHY to the rest of the system.
   */
  int sas_phy_add(struct sas_phy *phy)
  {
  	int error;
  
  	error = device_add(&phy->dev);
  	if (!error) {
  		transport_add_device(&phy->dev);
  		transport_configure_device(&phy->dev);
  	}
  
  	return error;
  }
  EXPORT_SYMBOL(sas_phy_add);
  
  /**
   * sas_phy_free  -  free a SAS PHY
   * @phy:	SAS PHY to free
   *
   * Frees the specified SAS PHY.
   *
   * Note:
   *   This function must only be called on a PHY that has not
   *   successfully been added using sas_phy_add().
   */
  void sas_phy_free(struct sas_phy *phy)
  {
  	transport_destroy_device(&phy->dev);
  	put_device(&phy->dev);
  }
  EXPORT_SYMBOL(sas_phy_free);
  
  /**
   * sas_phy_delete  -  remove SAS PHY
   * @phy:	SAS PHY to remove
   *
   * Removes the specified SAS PHY.  If the SAS PHY has an
   * associated remote PHY it is removed before.
   */
  void
  sas_phy_delete(struct sas_phy *phy)
  {
  	struct device *dev = &phy->dev;
  
  	/* this happens if the phy is still part of a port when deleted */
  	BUG_ON(!list_empty(&phy->port_siblings));
  
  	transport_remove_device(dev);
  	device_del(dev);
  	transport_destroy_device(dev);
  	put_device(dev);
  }
  EXPORT_SYMBOL(sas_phy_delete);
  
  /**
   * scsi_is_sas_phy  -  check if a struct device represents a SAS PHY
   * @dev:	device to check
   *
   * Returns:
   *	%1 if the device represents a SAS PHY, %0 else
   */
  int scsi_is_sas_phy(const struct device *dev)
  {
  	return dev->release == sas_phy_release;
  }
  EXPORT_SYMBOL(scsi_is_sas_phy);
  
  /*
   * SAS Port attributes
   */
  #define sas_port_show_simple(field, name, format_string, cast)		\
  static ssize_t								\
  show_sas_port_##name(struct device *dev, 				\
  		     struct device_attribute *attr, char *buf)		\
  {									\
  	struct sas_port *port = transport_class_to_sas_port(dev);	\
  									\
  	return snprintf(buf, 20, format_string, cast port->field);	\
  }
  
  #define sas_port_simple_attr(field, name, format_string, type)		\
  	sas_port_show_simple(field, name, format_string, (type))	\
  static DEVICE_ATTR(name, S_IRUGO, show_sas_port_##name, NULL)
  
  sas_port_simple_attr(num_phys, num_phys, "%d\n", int);
  
  static DECLARE_TRANSPORT_CLASS(sas_port_class,
  			       "sas_port", NULL, NULL, NULL);
  
  static int sas_port_match(struct attribute_container *cont, struct device *dev)
  {
  	struct Scsi_Host *shost;
  	struct sas_internal *i;
  
  	if (!scsi_is_sas_port(dev))
  		return 0;
  	shost = dev_to_shost(dev->parent);
  
  	if (!shost->transportt)
  		return 0;
  	if (shost->transportt->host_attrs.ac.class !=
  			&sas_host_class.class)
  		return 0;
  
  	i = to_sas_internal(shost->transportt);
  	return &i->port_attr_cont.ac == cont;
  }
  
  
  static void sas_port_release(struct device *dev)
  {
  	struct sas_port *port = dev_to_sas_port(dev);
  
  	BUG_ON(!list_empty(&port->phy_list));
  
  	put_device(dev->parent);
  	kfree(port);
  }
  
  static void sas_port_create_link(struct sas_port *port,
  				 struct sas_phy *phy)
  {
  	int res;
  
  	res = sysfs_create_link(&port->dev.kobj, &phy->dev.kobj,
  				dev_name(&phy->dev));
  	if (res)
  		goto err;
  	res = sysfs_create_link(&phy->dev.kobj, &port->dev.kobj, "port");
  	if (res)
  		goto err;
  	return;
  err:
  	printk(KERN_ERR "%s: Cannot create port links, err=%d\n",
  	       __func__, res);
  }
  
  static void sas_port_delete_link(struct sas_port *port,
  				 struct sas_phy *phy)
  {
  	sysfs_remove_link(&port->dev.kobj, dev_name(&phy->dev));
  	sysfs_remove_link(&phy->dev.kobj, "port");
  }
  
  /** sas_port_alloc - allocate and initialize a SAS port structure
   *
   * @parent:	parent device
   * @port_id:	port number
   *
   * Allocates a SAS port structure.  It will be added to the device tree
   * below the device specified by @parent which must be either a Scsi_Host
   * or a sas_expander_device.
   *
   * Returns %NULL on error
   */
  struct sas_port *sas_port_alloc(struct device *parent, int port_id)
  {
  	struct Scsi_Host *shost = dev_to_shost(parent);
  	struct sas_port *port;
  
  	port = kzalloc(sizeof(*port), GFP_KERNEL);
  	if (!port)
  		return NULL;
  
  	port->port_identifier = port_id;
  
  	device_initialize(&port->dev);
  
  	port->dev.parent = get_device(parent);
  	port->dev.release = sas_port_release;
  
  	mutex_init(&port->phy_list_mutex);
  	INIT_LIST_HEAD(&port->phy_list);
  
  	if (scsi_is_sas_expander_device(parent)) {
  		struct sas_rphy *rphy = dev_to_rphy(parent);
  		dev_set_name(&port->dev, "port-%d:%d:%d", shost->host_no,
  			     rphy->scsi_target_id, port->port_identifier);
  	} else
  		dev_set_name(&port->dev, "port-%d:%d", shost->host_no,
  			     port->port_identifier);
  
  	transport_setup_device(&port->dev);
  
  	return port;
  }
  EXPORT_SYMBOL(sas_port_alloc);
  
  /** sas_port_alloc_num - allocate and initialize a SAS port structure
   *
   * @parent:	parent device
   *
   * Allocates a SAS port structure and a number to go with it.  This
   * interface is really for adapters where the port number has no
   * meansing, so the sas class should manage them.  It will be added to
   * the device tree below the device specified by @parent which must be
   * either a Scsi_Host or a sas_expander_device.
   *
   * Returns %NULL on error
   */
  struct sas_port *sas_port_alloc_num(struct device *parent)
  {
  	int index;
  	struct Scsi_Host *shost = dev_to_shost(parent);
  	struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
  
  	/* FIXME: use idr for this eventually */
  	mutex_lock(&sas_host->lock);
  	if (scsi_is_sas_expander_device(parent)) {
  		struct sas_rphy *rphy = dev_to_rphy(parent);
  		struct sas_expander_device *exp = rphy_to_expander_device(rphy);
  
  		index = exp->next_port_id++;
  	} else
  		index = sas_host->next_port_id++;
  	mutex_unlock(&sas_host->lock);
  	return sas_port_alloc(parent, index);
  }
  EXPORT_SYMBOL(sas_port_alloc_num);
  
  /**
   * sas_port_add - add a SAS port to the device hierarchy
   * @port:	port to be added
   *
   * publishes a port to the rest of the system
   */
  int sas_port_add(struct sas_port *port)
  {
  	int error;
  
  	/* No phys should be added until this is made visible */
  	BUG_ON(!list_empty(&port->phy_list));
  
  	error = device_add(&port->dev);
  
  	if (error)
  		return error;
  
  	transport_add_device(&port->dev);
  	transport_configure_device(&port->dev);
  
  	return 0;
  }
  EXPORT_SYMBOL(sas_port_add);
  
  /**
   * sas_port_free  -  free a SAS PORT
   * @port:	SAS PORT to free
   *
   * Frees the specified SAS PORT.
   *
   * Note:
   *   This function must only be called on a PORT that has not
   *   successfully been added using sas_port_add().
   */
  void sas_port_free(struct sas_port *port)
  {
  	transport_destroy_device(&port->dev);
  	put_device(&port->dev);
  }
  EXPORT_SYMBOL(sas_port_free);
  
  /**
   * sas_port_delete  -  remove SAS PORT
   * @port:	SAS PORT to remove
   *
   * Removes the specified SAS PORT.  If the SAS PORT has an
   * associated phys, unlink them from the port as well.
   */
  void sas_port_delete(struct sas_port *port)
  {
  	struct device *dev = &port->dev;
  	struct sas_phy *phy, *tmp_phy;
  
  	if (port->rphy) {
  		sas_rphy_delete(port->rphy);
  		port->rphy = NULL;
  	}
  
  	mutex_lock(&port->phy_list_mutex);
  	list_for_each_entry_safe(phy, tmp_phy, &port->phy_list,
  				 port_siblings) {
  		sas_port_delete_link(port, phy);
  		list_del_init(&phy->port_siblings);
  	}
  	mutex_unlock(&port->phy_list_mutex);
  
  	if (port->is_backlink) {
  		struct device *parent = port->dev.parent;
  
  		sysfs_remove_link(&port->dev.kobj, dev_name(parent));
  		port->is_backlink = 0;
  	}
  
  	transport_remove_device(dev);
  	device_del(dev);
  	transport_destroy_device(dev);
  	put_device(dev);
  }
  EXPORT_SYMBOL(sas_port_delete);
  
  /**
   * scsi_is_sas_port -  check if a struct device represents a SAS port
   * @dev:	device to check
   *
   * Returns:
   *	%1 if the device represents a SAS Port, %0 else
   */
  int scsi_is_sas_port(const struct device *dev)
  {
  	return dev->release == sas_port_release;
  }
  EXPORT_SYMBOL(scsi_is_sas_port);
  
  /**
   * sas_port_get_phy - try to take a reference on a port member
   * @port: port to check
   */
  struct sas_phy *sas_port_get_phy(struct sas_port *port)
  {
  	struct sas_phy *phy;
  
  	mutex_lock(&port->phy_list_mutex);
  	if (list_empty(&port->phy_list))
  		phy = NULL;
  	else {
  		struct list_head *ent = port->phy_list.next;
  
  		phy = list_entry(ent, typeof(*phy), port_siblings);
  		get_device(&phy->dev);
  	}
  	mutex_unlock(&port->phy_list_mutex);
  
  	return phy;
  }
  EXPORT_SYMBOL(sas_port_get_phy);
  
  /**
   * sas_port_add_phy - add another phy to a port to form a wide port
   * @port:	port to add the phy to
   * @phy:	phy to add
   *
   * When a port is initially created, it is empty (has no phys).  All
   * ports must have at least one phy to operated, and all wide ports
   * must have at least two.  The current code makes no difference
   * between ports and wide ports, but the only object that can be
   * connected to a remote device is a port, so ports must be formed on
   * all devices with phys if they're connected to anything.
   */
  void sas_port_add_phy(struct sas_port *port, struct sas_phy *phy)
  {
  	mutex_lock(&port->phy_list_mutex);
  	if (unlikely(!list_empty(&phy->port_siblings))) {
  		/* make sure we're already on this port */
  		struct sas_phy *tmp;
  
  		list_for_each_entry(tmp, &port->phy_list, port_siblings)
  			if (tmp == phy)
  				break;
  		/* If this trips, you added a phy that was already
  		 * part of a different port */
  		if (unlikely(tmp != phy)) {
  			dev_printk(KERN_ERR, &port->dev, "trying to add phy %s fails: it's already part of another port\n",
  				   dev_name(&phy->dev));
  			BUG();
  		}
  	} else {
  		sas_port_create_link(port, phy);
  		list_add_tail(&phy->port_siblings, &port->phy_list);
  		port->num_phys++;
  	}
  	mutex_unlock(&port->phy_list_mutex);
  }
  EXPORT_SYMBOL(sas_port_add_phy);
  
  /**
   * sas_port_delete_phy - remove a phy from a port or wide port
   * @port:	port to remove the phy from
   * @phy:	phy to remove
   *
   * This operation is used for tearing down ports again.  It must be
   * done to every port or wide port before calling sas_port_delete.
   */
  void sas_port_delete_phy(struct sas_port *port, struct sas_phy *phy)
  {
  	mutex_lock(&port->phy_list_mutex);
  	sas_port_delete_link(port, phy);
  	list_del_init(&phy->port_siblings);
  	port->num_phys--;
  	mutex_unlock(&port->phy_list_mutex);
  }
  EXPORT_SYMBOL(sas_port_delete_phy);
  
  void sas_port_mark_backlink(struct sas_port *port)
  {
  	int res;
  	struct device *parent = port->dev.parent->parent->parent;
  
  	if (port->is_backlink)
  		return;
  	port->is_backlink = 1;
  	res = sysfs_create_link(&port->dev.kobj, &parent->kobj,
  				dev_name(parent));
  	if (res)
  		goto err;
  	return;
  err:
  	printk(KERN_ERR "%s: Cannot create port backlink, err=%d\n",
  	       __func__, res);
  
  }
  EXPORT_SYMBOL(sas_port_mark_backlink);
  
  /*
   * SAS remote PHY attributes.
   */
  
  #define sas_rphy_show_simple(field, name, format_string, cast)		\
  static ssize_t								\
  show_sas_rphy_##name(struct device *dev, 				\
  		     struct device_attribute *attr, char *buf)		\
  {									\
  	struct sas_rphy *rphy = transport_class_to_rphy(dev);		\
  									\
  	return snprintf(buf, 20, format_string, cast rphy->field);	\
  }
  
  #define sas_rphy_simple_attr(field, name, format_string, type)		\
  	sas_rphy_show_simple(field, name, format_string, (type))	\
  static SAS_DEVICE_ATTR(rphy, name, S_IRUGO, 			\
  		show_sas_rphy_##name, NULL)
  
  #define sas_rphy_show_protocol(field, name)				\
  static ssize_t								\
  show_sas_rphy_##name(struct device *dev, 				\
  		     struct device_attribute *attr, char *buf)		\
  {									\
  	struct sas_rphy *rphy = transport_class_to_rphy(dev);		\
  									\
  	if (!rphy->field)					\
  		return snprintf(buf, 20, "none\n");			\
  	return get_sas_protocol_names(rphy->field, buf);	\
  }
  
  #define sas_rphy_protocol_attr(field, name)				\
  	sas_rphy_show_protocol(field, name)				\
  static SAS_DEVICE_ATTR(rphy, name, S_IRUGO,			\
  		show_sas_rphy_##name, NULL)
  
  static ssize_t
  show_sas_rphy_device_type(struct device *dev,
  			  struct device_attribute *attr, char *buf)
  {
  	struct sas_rphy *rphy = transport_class_to_rphy(dev);
  
  	if (!rphy->identify.device_type)
  		return snprintf(buf, 20, "none\n");
  	return get_sas_device_type_names(
  			rphy->identify.device_type, buf);
  }
  
  static SAS_DEVICE_ATTR(rphy, device_type, S_IRUGO,
  		show_sas_rphy_device_type, NULL);
  
  static ssize_t
  show_sas_rphy_enclosure_identifier(struct device *dev,
  				   struct device_attribute *attr, char *buf)
  {
  	struct sas_rphy *rphy = transport_class_to_rphy(dev);
  	struct sas_phy *phy = dev_to_phy(rphy->dev.parent);
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
  	struct sas_internal *i = to_sas_internal(shost->transportt);
  	u64 identifier;
  	int error;
  
  	error = i->f->get_enclosure_identifier(rphy, &identifier);
  	if (error)
  		return error;
  	return sprintf(buf, "0x%llx\n", (unsigned long long)identifier);
  }
  
  static SAS_DEVICE_ATTR(rphy, enclosure_identifier, S_IRUGO,
  		show_sas_rphy_enclosure_identifier, NULL);
  
  static ssize_t
  show_sas_rphy_bay_identifier(struct device *dev,
  			     struct device_attribute *attr, char *buf)
  {
  	struct sas_rphy *rphy = transport_class_to_rphy(dev);
  	struct sas_phy *phy = dev_to_phy(rphy->dev.parent);
  	struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);
  	struct sas_internal *i = to_sas_internal(shost->transportt);
  	int val;
  
  	val = i->f->get_bay_identifier(rphy);
  	if (val < 0)
  		return val;
  	return sprintf(buf, "%d\n", val);
  }
  
  static SAS_DEVICE_ATTR(rphy, bay_identifier, S_IRUGO,
  		show_sas_rphy_bay_identifier, NULL);
  
  sas_rphy_protocol_attr(identify.initiator_port_protocols,
  		initiator_port_protocols);
  sas_rphy_protocol_attr(identify.target_port_protocols, target_port_protocols);
  sas_rphy_simple_attr(identify.sas_address, sas_address, "0x%016llx\n",
  		unsigned long long);
  sas_rphy_simple_attr(identify.phy_identifier, phy_identifier, "%d\n", u8);
  sas_rphy_simple_attr(scsi_target_id, scsi_target_id, "%d\n", u32);
  
  /* only need 8 bytes of data plus header (4 or 8) */
  #define BUF_SIZE 64
  
  int sas_read_port_mode_page(struct scsi_device *sdev)
  {
  	char *buffer = kzalloc(BUF_SIZE, GFP_KERNEL), *msdata;
  	struct sas_end_device *rdev = sas_sdev_to_rdev(sdev);
  	struct scsi_mode_data mode_data;
  	int res, error;
  
  	if (!buffer)
  		return -ENOMEM;
  
  	res = scsi_mode_sense(sdev, 1, 0x19, buffer, BUF_SIZE, 30*HZ, 3,
  			      &mode_data, NULL);
  
  	error = -EINVAL;
  	if (!scsi_status_is_good(res))
  		goto out;
  
  	msdata = buffer +  mode_data.header_length +
  		mode_data.block_descriptor_length;
  
  	if (msdata - buffer > BUF_SIZE - 8)
  		goto out;
  
  	error = 0;
  
  	rdev->ready_led_meaning = msdata[2] & 0x10 ? 1 : 0;
  	rdev->I_T_nexus_loss_timeout = (msdata[4] << 8) + msdata[5];
  	rdev->initiator_response_timeout = (msdata[6] << 8) + msdata[7];
  
   out:
  	kfree(buffer);
  	return error;
  }
  EXPORT_SYMBOL(sas_read_port_mode_page);
  
  static DECLARE_TRANSPORT_CLASS(sas_end_dev_class,
  			       "sas_end_device", NULL, NULL, NULL);
  
  #define sas_end_dev_show_simple(field, name, format_string, cast)	\
  static ssize_t								\
  show_sas_end_dev_##name(struct device *dev, 				\
  			struct device_attribute *attr, char *buf)	\
  {									\
  	struct sas_rphy *rphy = transport_class_to_rphy(dev);		\
  	struct sas_end_device *rdev = rphy_to_end_device(rphy);		\
  									\
  	return snprintf(buf, 20, format_string, cast rdev->field);	\
  }
  
  #define sas_end_dev_simple_attr(field, name, format_string, type)	\
  	sas_end_dev_show_simple(field, name, format_string, (type))	\
  static SAS_DEVICE_ATTR(end_dev, name, S_IRUGO, 			\
  		show_sas_end_dev_##name, NULL)
  
  sas_end_dev_simple_attr(ready_led_meaning, ready_led_meaning, "%d\n", int);
  sas_end_dev_simple_attr(I_T_nexus_loss_timeout, I_T_nexus_loss_timeout,
  			"%d\n", int);
  sas_end_dev_simple_attr(initiator_response_timeout, initiator_response_timeout,
  			"%d\n", int);
  sas_end_dev_simple_attr(tlr_supported, tlr_supported,
  			"%d\n", int);
  sas_end_dev_simple_attr(tlr_enabled, tlr_enabled,
  			"%d\n", int);
  
  static DECLARE_TRANSPORT_CLASS(sas_expander_class,
  			       "sas_expander", NULL, NULL, NULL);
  
  #define sas_expander_show_simple(field, name, format_string, cast)	\
  static ssize_t								\
  show_sas_expander_##name(struct device *dev, 				\
  			 struct device_attribute *attr, char *buf)	\
  {									\
  	struct sas_rphy *rphy = transport_class_to_rphy(dev);		\
  	struct sas_expander_device *edev = rphy_to_expander_device(rphy); \
  									\
  	return snprintf(buf, 20, format_string, cast edev->field);	\
  }
  
  #define sas_expander_simple_attr(field, name, format_string, type)	\
  	sas_expander_show_simple(field, name, format_string, (type))	\
  static SAS_DEVICE_ATTR(expander, name, S_IRUGO, 			\
  		show_sas_expander_##name, NULL)
  
  sas_expander_simple_attr(vendor_id, vendor_id, "%s\n", char *);
  sas_expander_simple_attr(product_id, product_id, "%s\n", char *);
  sas_expander_simple_attr(product_rev, product_rev, "%s\n", char *);
  sas_expander_simple_attr(component_vendor_id, component_vendor_id,
  			 "%s\n", char *);
  sas_expander_simple_attr(component_id, component_id, "%u\n", unsigned int);
  sas_expander_simple_attr(component_revision_id, component_revision_id, "%u\n",
  			 unsigned int);
  sas_expander_simple_attr(level, level, "%d\n", int);
  
  static DECLARE_TRANSPORT_CLASS(sas_rphy_class,
  		"sas_device", NULL, NULL, NULL);
  
  static int sas_rphy_match(struct attribute_container *cont, struct device *dev)
  {
  	struct Scsi_Host *shost;
  	struct sas_internal *i;
  
  	if (!scsi_is_sas_rphy(dev))
  		return 0;
  	shost = dev_to_shost(dev->parent->parent);
  
  	if (!shost->transportt)
  		return 0;
  	if (shost->transportt->host_attrs.ac.class !=
  			&sas_host_class.class)
  		return 0;
  
  	i = to_sas_internal(shost->transportt);
  	return &i->rphy_attr_cont.ac == cont;
  }
  
  static int sas_end_dev_match(struct attribute_container *cont,
  			     struct device *dev)
  {
  	struct Scsi_Host *shost;
  	struct sas_internal *i;
  	struct sas_rphy *rphy;
  
  	if (!scsi_is_sas_rphy(dev))
  		return 0;
  	shost = dev_to_shost(dev->parent->parent);
  	rphy = dev_to_rphy(dev);
  
  	if (!shost->transportt)
  		return 0;
  	if (shost->transportt->host_attrs.ac.class !=
  			&sas_host_class.class)
  		return 0;
  
  	i = to_sas_internal(shost->transportt);
  	return &i->end_dev_attr_cont.ac == cont &&
  		rphy->identify.device_type == SAS_END_DEVICE;
  }
  
  static int sas_expander_match(struct attribute_container *cont,
  			      struct device *dev)
  {
  	struct Scsi_Host *shost;
  	struct sas_internal *i;
  	struct sas_rphy *rphy;
  
  	if (!scsi_is_sas_rphy(dev))
  		return 0;
  	shost = dev_to_shost(dev->parent->parent);
  	rphy = dev_to_rphy(dev);
  
  	if (!shost->transportt)
  		return 0;
  	if (shost->transportt->host_attrs.ac.class !=
  			&sas_host_class.class)
  		return 0;
  
  	i = to_sas_internal(shost->transportt);
  	return &i->expander_attr_cont.ac == cont &&
  		(rphy->identify.device_type == SAS_EDGE_EXPANDER_DEVICE ||
  		 rphy->identify.device_type == SAS_FANOUT_EXPANDER_DEVICE);
  }
  
  static void sas_expander_release(struct device *dev)
  {
  	struct sas_rphy *rphy = dev_to_rphy(dev);
  	struct sas_expander_device *edev = rphy_to_expander_device(rphy);
  
  	if (rphy->q)
  		blk_cleanup_queue(rphy->q);
  
  	put_device(dev->parent);
  	kfree(edev);
  }
  
  static void sas_end_device_release(struct device *dev)
  {
  	struct sas_rphy *rphy = dev_to_rphy(dev);
  	struct sas_end_device *edev = rphy_to_end_device(rphy);
  
  	if (rphy->q)
  		blk_cleanup_queue(rphy->q);
  
  	put_device(dev->parent);
  	kfree(edev);
  }
  
  /**
   * sas_rphy_initialize - common rphy initialization
   * @rphy:	rphy to initialise
   *
   * Used by both sas_end_device_alloc() and sas_expander_alloc() to
   * initialise the common rphy component of each.
   */
  static void sas_rphy_initialize(struct sas_rphy *rphy)
  {
  	INIT_LIST_HEAD(&rphy->list);
  }
  
  /**
   * sas_end_device_alloc - allocate an rphy for an end device
   * @parent: which port
   *
   * Allocates an SAS remote PHY structure, connected to @parent.
   *
   * Returns:
   *	SAS PHY allocated or %NULL if the allocation failed.
   */
  struct sas_rphy *sas_end_device_alloc(struct sas_port *parent)
  {
  	struct Scsi_Host *shost = dev_to_shost(&parent->dev);
  	struct sas_end_device *rdev;
  
  	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
  	if (!rdev) {
  		return NULL;
  	}
  
  	device_initialize(&rdev->rphy.dev);
  	rdev->rphy.dev.parent = get_device(&parent->dev);
  	rdev->rphy.dev.release = sas_end_device_release;
  	if (scsi_is_sas_expander_device(parent->dev.parent)) {
  		struct sas_rphy *rphy = dev_to_rphy(parent->dev.parent);
  		dev_set_name(&rdev->rphy.dev, "end_device-%d:%d:%d",
  			     shost->host_no, rphy->scsi_target_id,
  			     parent->port_identifier);
  	} else
  		dev_set_name(&rdev->rphy.dev, "end_device-%d:%d",
  			     shost->host_no, parent->port_identifier);
  	rdev->rphy.identify.device_type = SAS_END_DEVICE;
  	sas_rphy_initialize(&rdev->rphy);
  	transport_setup_device(&rdev->rphy.dev);
  
  	return &rdev->rphy;
  }
  EXPORT_SYMBOL(sas_end_device_alloc);
  
  /**
   * sas_expander_alloc - allocate an rphy for an end device
   * @parent: which port
   * @type: SAS_EDGE_EXPANDER_DEVICE or SAS_FANOUT_EXPANDER_DEVICE
   *
   * Allocates an SAS remote PHY structure, connected to @parent.
   *
   * Returns:
   *	SAS PHY allocated or %NULL if the allocation failed.
   */
  struct sas_rphy *sas_expander_alloc(struct sas_port *parent,
  				    enum sas_device_type type)
  {
  	struct Scsi_Host *shost = dev_to_shost(&parent->dev);
  	struct sas_expander_device *rdev;
  	struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
  
  	BUG_ON(type != SAS_EDGE_EXPANDER_DEVICE &&
  	       type != SAS_FANOUT_EXPANDER_DEVICE);
  
  	rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
  	if (!rdev) {
  		return NULL;
  	}
  
  	device_initialize(&rdev->rphy.dev);
  	rdev->rphy.dev.parent = get_device(&parent->dev);
  	rdev->rphy.dev.release = sas_expander_release;
  	mutex_lock(&sas_host->lock);
  	rdev->rphy.scsi_target_id = sas_host->next_expander_id++;
  	mutex_unlock(&sas_host->lock);
  	dev_set_name(&rdev->rphy.dev, "expander-%d:%d",
  		     shost->host_no, rdev->rphy.scsi_target_id);
  	rdev->rphy.identify.device_type = type;
  	sas_rphy_initialize(&rdev->rphy);
  	transport_setup_device(&rdev->rphy.dev);
  
  	return &rdev->rphy;
  }
  EXPORT_SYMBOL(sas_expander_alloc);
  
  /**
   * sas_rphy_add  -  add a SAS remote PHY to the device hierarchy
   * @rphy:	The remote PHY to be added
   *
   * Publishes a SAS remote PHY to the rest of the system.
   */
  int sas_rphy_add(struct sas_rphy *rphy)
  {
  	struct sas_port *parent = dev_to_sas_port(rphy->dev.parent);
  	struct Scsi_Host *shost = dev_to_shost(parent->dev.parent);
  	struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
  	struct sas_identify *identify = &rphy->identify;
  	int error;
  
  	if (parent->rphy)
  		return -ENXIO;
  	parent->rphy = rphy;
  
  	error = device_add(&rphy->dev);
  	if (error)
  		return error;
  	transport_add_device(&rphy->dev);
  	transport_configure_device(&rphy->dev);
  	if (sas_bsg_initialize(shost, rphy))
  		printk("fail to a bsg device %s\n", dev_name(&rphy->dev));
  
  
  	mutex_lock(&sas_host->lock);
  	list_add_tail(&rphy->list, &sas_host->rphy_list);
  	if (identify->device_type == SAS_END_DEVICE &&
  	    (identify->target_port_protocols &
  	     (SAS_PROTOCOL_SSP|SAS_PROTOCOL_STP|SAS_PROTOCOL_SATA)))
  		rphy->scsi_target_id = sas_host->next_target_id++;
  	else if (identify->device_type == SAS_END_DEVICE)
  		rphy->scsi_target_id = -1;
  	mutex_unlock(&sas_host->lock);
  
  	if (identify->device_type == SAS_END_DEVICE &&
  	    rphy->scsi_target_id != -1) {
  		int lun;
  
  		if (identify->target_port_protocols & SAS_PROTOCOL_SSP)
  			lun = SCAN_WILD_CARD;
  		else
  			lun = 0;
  
  		scsi_scan_target(&rphy->dev, 0, rphy->scsi_target_id, lun,
  				 SCSI_SCAN_INITIAL);
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL(sas_rphy_add);
  
  /**
   * sas_rphy_free  -  free a SAS remote PHY
   * @rphy: SAS remote PHY to free
   *
   * Frees the specified SAS remote PHY.
   *
   * Note:
   *   This function must only be called on a remote
   *   PHY that has not successfully been added using
   *   sas_rphy_add() (or has been sas_rphy_remove()'d)
   */
  void sas_rphy_free(struct sas_rphy *rphy)
  {
  	struct device *dev = &rphy->dev;
  	struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent->parent);
  	struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
  
  	mutex_lock(&sas_host->lock);
  	list_del(&rphy->list);
  	mutex_unlock(&sas_host->lock);
  
  	transport_destroy_device(dev);
  
  	put_device(dev);
  }
  EXPORT_SYMBOL(sas_rphy_free);
  
  /**
   * sas_rphy_delete  -  remove and free SAS remote PHY
   * @rphy:	SAS remote PHY to remove and free
   *
   * Removes the specified SAS remote PHY and frees it.
   */
  void
  sas_rphy_delete(struct sas_rphy *rphy)
  {
  	sas_rphy_remove(rphy);
  	sas_rphy_free(rphy);
  }
  EXPORT_SYMBOL(sas_rphy_delete);
  
  /**
   * sas_rphy_unlink  -  unlink SAS remote PHY
   * @rphy:	SAS remote phy to unlink from its parent port
   *
   * Removes port reference to an rphy
   */
  void sas_rphy_unlink(struct sas_rphy *rphy)
  {
  	struct sas_port *parent = dev_to_sas_port(rphy->dev.parent);
  
  	parent->rphy = NULL;
  }
  EXPORT_SYMBOL(sas_rphy_unlink);
  
  /**
   * sas_rphy_remove  -  remove SAS remote PHY
   * @rphy:	SAS remote phy to remove
   *
   * Removes the specified SAS remote PHY.
   */
  void
  sas_rphy_remove(struct sas_rphy *rphy)
  {
  	struct device *dev = &rphy->dev;
  
  	switch (rphy->identify.device_type) {
  	case SAS_END_DEVICE:
  		scsi_remove_target(dev);
  		break;
  	case SAS_EDGE_EXPANDER_DEVICE:
  	case SAS_FANOUT_EXPANDER_DEVICE:
  		sas_remove_children(dev);
  		break;
  	default:
  		break;
  	}
  
  	sas_rphy_unlink(rphy);
  	sas_bsg_remove(NULL, rphy);
  	transport_remove_device(dev);
  	device_del(dev);
  }
  EXPORT_SYMBOL(sas_rphy_remove);
  
  /**
   * scsi_is_sas_rphy  -  check if a struct device represents a SAS remote PHY
   * @dev:	device to check
   *
   * Returns:
   *	%1 if the device represents a SAS remote PHY, %0 else
   */
  int scsi_is_sas_rphy(const struct device *dev)
  {
  	return dev->release == sas_end_device_release ||
  		dev->release == sas_expander_release;
  }
  EXPORT_SYMBOL(scsi_is_sas_rphy);
  
  
  /*
   * SCSI scan helper
   */
  
  static int sas_user_scan(struct Scsi_Host *shost, uint channel,
  		uint id, u64 lun)
  {
  	struct sas_host_attrs *sas_host = to_sas_host_attrs(shost);
  	struct sas_rphy *rphy;
  
  	mutex_lock(&sas_host->lock);
  	list_for_each_entry(rphy, &sas_host->rphy_list, list) {
  		if (rphy->identify.device_type != SAS_END_DEVICE ||
  		    rphy->scsi_target_id == -1)
  			continue;
  
  		if ((channel == SCAN_WILD_CARD || channel == 0) &&
  		    (id == SCAN_WILD_CARD || id == rphy->scsi_target_id)) {
  			scsi_scan_target(&rphy->dev, 0, rphy->scsi_target_id,
  					 lun, SCSI_SCAN_MANUAL);
  		}
  	}
  	mutex_unlock(&sas_host->lock);
  
  	return 0;
  }
  
  
  /*
   * Setup / Teardown code
   */
  
  #define SETUP_TEMPLATE(attrb, field, perm, test)			\
  	i->private_##attrb[count] = dev_attr_##field;		\
  	i->private_##attrb[count].attr.mode = perm;			\
  	i->attrb[count] = &i->private_##attrb[count];			\
  	if (test)							\
  		count++
  
  #define SETUP_TEMPLATE_RW(attrb, field, perm, test, ro_test, ro_perm)	\
  	i->private_##attrb[count] = dev_attr_##field;		\
  	i->private_##attrb[count].attr.mode = perm;			\
  	if (ro_test) {							\
  		i->private_##attrb[count].attr.mode = ro_perm;		\
  		i->private_##attrb[count].store = NULL;			\
  	}								\
  	i->attrb[count] = &i->private_##attrb[count];			\
  	if (test)							\
  		count++
  
  #define SETUP_RPORT_ATTRIBUTE(field) 					\
  	SETUP_TEMPLATE(rphy_attrs, field, S_IRUGO, 1)
  
  #define SETUP_OPTIONAL_RPORT_ATTRIBUTE(field, func)			\
  	SETUP_TEMPLATE(rphy_attrs, field, S_IRUGO, i->f->func)
  
  #define SETUP_PHY_ATTRIBUTE(field)					\
  	SETUP_TEMPLATE(phy_attrs, field, S_IRUGO, 1)
  
  #define SETUP_PHY_ATTRIBUTE_RW(field)					\
  	SETUP_TEMPLATE_RW(phy_attrs, field, S_IRUGO | S_IWUSR, 1,	\
  			!i->f->set_phy_speed, S_IRUGO)
  
  #define SETUP_OPTIONAL_PHY_ATTRIBUTE_RW(field, func)			\
  	SETUP_TEMPLATE_RW(phy_attrs, field, S_IRUGO | S_IWUSR, 1,	\
  			  !i->f->func, S_IRUGO)
  
  #define SETUP_PORT_ATTRIBUTE(field)					\
  	SETUP_TEMPLATE(port_attrs, field, S_IRUGO, 1)
  
  #define SETUP_OPTIONAL_PHY_ATTRIBUTE(field, func)			\
  	SETUP_TEMPLATE(phy_attrs, field, S_IRUGO, i->f->func)
  
  #define SETUP_PHY_ATTRIBUTE_WRONLY(field)				\
  	SETUP_TEMPLATE(phy_attrs, field, S_IWUSR, 1)
  
  #define SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(field, func)		\
  	SETUP_TEMPLATE(phy_attrs, field, S_IWUSR, i->f->func)
  
  #define SETUP_END_DEV_ATTRIBUTE(field)					\
  	SETUP_TEMPLATE(end_dev_attrs, field, S_IRUGO, 1)
  
  #define SETUP_EXPANDER_ATTRIBUTE(field)					\
  	SETUP_TEMPLATE(expander_attrs, expander_##field, S_IRUGO, 1)
  
  /**
   * sas_attach_transport  -  instantiate SAS transport template
   * @ft:		SAS transport class function template
   */
  struct scsi_transport_template *
  sas_attach_transport(struct sas_function_template *ft)
  {
  	struct sas_internal *i;
  	int count;
  
  	i = kzalloc(sizeof(struct sas_internal), GFP_KERNEL);
  	if (!i)
  		return NULL;
  
  	i->t.user_scan = sas_user_scan;
  
  	i->t.host_attrs.ac.attrs = &i->host_attrs[0];
  	i->t.host_attrs.ac.class = &sas_host_class.class;
  	i->t.host_attrs.ac.match = sas_host_match;
  	transport_container_register(&i->t.host_attrs);
  	i->t.host_size = sizeof(struct sas_host_attrs);
  
  	i->phy_attr_cont.ac.class = &sas_phy_class.class;
  	i->phy_attr_cont.ac.attrs = &i->phy_attrs[0];
  	i->phy_attr_cont.ac.match = sas_phy_match;
  	transport_container_register(&i->phy_attr_cont);
  
  	i->port_attr_cont.ac.class = &sas_port_class.class;
  	i->port_attr_cont.ac.attrs = &i->port_attrs[0];
  	i->port_attr_cont.ac.match = sas_port_match;
  	transport_container_register(&i->port_attr_cont);
  
  	i->rphy_attr_cont.ac.class = &sas_rphy_class.class;
  	i->rphy_attr_cont.ac.attrs = &i->rphy_attrs[0];
  	i->rphy_attr_cont.ac.match = sas_rphy_match;
  	transport_container_register(&i->rphy_attr_cont);
  
  	i->end_dev_attr_cont.ac.class = &sas_end_dev_class.class;
  	i->end_dev_attr_cont.ac.attrs = &i->end_dev_attrs[0];
  	i->end_dev_attr_cont.ac.match = sas_end_dev_match;
  	transport_container_register(&i->end_dev_attr_cont);
  
  	i->expander_attr_cont.ac.class = &sas_expander_class.class;
  	i->expander_attr_cont.ac.attrs = &i->expander_attrs[0];
  	i->expander_attr_cont.ac.match = sas_expander_match;
  	transport_container_register(&i->expander_attr_cont);
  
  	i->f = ft;
  
  	count = 0;
  	SETUP_PHY_ATTRIBUTE(initiator_port_protocols);
  	SETUP_PHY_ATTRIBUTE(target_port_protocols);
  	SETUP_PHY_ATTRIBUTE(device_type);
  	SETUP_PHY_ATTRIBUTE(sas_address);
  	SETUP_PHY_ATTRIBUTE(phy_identifier);
  	//SETUP_PHY_ATTRIBUTE(port_identifier);
  	SETUP_PHY_ATTRIBUTE(negotiated_linkrate);
  	SETUP_PHY_ATTRIBUTE(minimum_linkrate_hw);
  	SETUP_PHY_ATTRIBUTE_RW(minimum_linkrate);
  	SETUP_PHY_ATTRIBUTE(maximum_linkrate_hw);
  	SETUP_PHY_ATTRIBUTE_RW(maximum_linkrate);
  
  	SETUP_PHY_ATTRIBUTE(invalid_dword_count);
  	SETUP_PHY_ATTRIBUTE(running_disparity_error_count);
  	SETUP_PHY_ATTRIBUTE(loss_of_dword_sync_count);
  	SETUP_PHY_ATTRIBUTE(phy_reset_problem_count);
  	SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(link_reset, phy_reset);
  	SETUP_OPTIONAL_PHY_ATTRIBUTE_WRONLY(hard_reset, phy_reset);
  	SETUP_OPTIONAL_PHY_ATTRIBUTE_RW(enable, phy_enable);
  	i->phy_attrs[count] = NULL;
  
  	count = 0;
  	SETUP_PORT_ATTRIBUTE(num_phys);
  	i->port_attrs[count] = NULL;
  
  	count = 0;
  	SETUP_RPORT_ATTRIBUTE(rphy_initiator_port_protocols);
  	SETUP_RPORT_ATTRIBUTE(rphy_target_port_protocols);
  	SETUP_RPORT_ATTRIBUTE(rphy_device_type);
  	SETUP_RPORT_ATTRIBUTE(rphy_sas_address);
  	SETUP_RPORT_ATTRIBUTE(rphy_phy_identifier);
  	SETUP_RPORT_ATTRIBUTE(rphy_scsi_target_id);
  	SETUP_OPTIONAL_RPORT_ATTRIBUTE(rphy_enclosure_identifier,
  				       get_enclosure_identifier);
  	SETUP_OPTIONAL_RPORT_ATTRIBUTE(rphy_bay_identifier,
  				       get_bay_identifier);
  	i->rphy_attrs[count] = NULL;
  
  	count = 0;
  	SETUP_END_DEV_ATTRIBUTE(end_dev_ready_led_meaning);
  	SETUP_END_DEV_ATTRIBUTE(end_dev_I_T_nexus_loss_timeout);
  	SETUP_END_DEV_ATTRIBUTE(end_dev_initiator_response_timeout);
  	SETUP_END_DEV_ATTRIBUTE(end_dev_tlr_supported);
  	SETUP_END_DEV_ATTRIBUTE(end_dev_tlr_enabled);
  	i->end_dev_attrs[count] = NULL;
  
  	count = 0;
  	SETUP_EXPANDER_ATTRIBUTE(vendor_id);
  	SETUP_EXPANDER_ATTRIBUTE(product_id);
  	SETUP_EXPANDER_ATTRIBUTE(product_rev);
  	SETUP_EXPANDER_ATTRIBUTE(component_vendor_id);
  	SETUP_EXPANDER_ATTRIBUTE(component_id);
  	SETUP_EXPANDER_ATTRIBUTE(component_revision_id);
  	SETUP_EXPANDER_ATTRIBUTE(level);
  	i->expander_attrs[count] = NULL;
  
  	return &i->t;
  }
  EXPORT_SYMBOL(sas_attach_transport);
  
  /**
   * sas_release_transport  -  release SAS transport template instance
   * @t:		transport template instance
   */
  void sas_release_transport(struct scsi_transport_template *t)
  {
  	struct sas_internal *i = to_sas_internal(t);
  
  	transport_container_unregister(&i->t.host_attrs);
  	transport_container_unregister(&i->phy_attr_cont);
  	transport_container_unregister(&i->port_attr_cont);
  	transport_container_unregister(&i->rphy_attr_cont);
  	transport_container_unregister(&i->end_dev_attr_cont);
  	transport_container_unregister(&i->expander_attr_cont);
  
  	kfree(i);
  }
  EXPORT_SYMBOL(sas_release_transport);
  
  static __init int sas_transport_init(void)
  {
  	int error;
  
  	error = transport_class_register(&sas_host_class);
  	if (error)
  		goto out;
  	error = transport_class_register(&sas_phy_class);
  	if (error)
  		goto out_unregister_transport;
  	error = transport_class_register(&sas_port_class);
  	if (error)
  		goto out_unregister_phy;
  	error = transport_class_register(&sas_rphy_class);
  	if (error)
  		goto out_unregister_port;
  	error = transport_class_register(&sas_end_dev_class);
  	if (error)
  		goto out_unregister_rphy;
  	error = transport_class_register(&sas_expander_class);
  	if (error)
  		goto out_unregister_end_dev;
  
  	return 0;
  
   out_unregister_end_dev:
  	transport_class_unregister(&sas_end_dev_class);
   out_unregister_rphy:
  	transport_class_unregister(&sas_rphy_class);
   out_unregister_port:
  	transport_class_unregister(&sas_port_class);
   out_unregister_phy:
  	transport_class_unregister(&sas_phy_class);
   out_unregister_transport:
  	transport_class_unregister(&sas_host_class);
   out:
  	return error;
  
  }
  
  static void __exit sas_transport_exit(void)
  {
  	transport_class_unregister(&sas_host_class);
  	transport_class_unregister(&sas_phy_class);
  	transport_class_unregister(&sas_port_class);
  	transport_class_unregister(&sas_rphy_class);
  	transport_class_unregister(&sas_end_dev_class);
  	transport_class_unregister(&sas_expander_class);
  }
  
  MODULE_AUTHOR("Christoph Hellwig");
  MODULE_DESCRIPTION("SAS Transport Attributes");
  MODULE_LICENSE("GPL");
  
  module_init(sas_transport_init);
  module_exit(sas_transport_exit);
  