[SCSI] aic94xx: new driver

This is the end point of the separate aic94xx driver based on the
original driver and transport class from Luben Tuikov
<ltuikov@yahoo.com>

The log of the separate development is:

Alexis Bruemmer:
  o aic94xx: fix hotplug/unplug for expanderless systems
  o aic94xx: disable split completion timer/setting by default
  o aic94xx: wide port off expander support
  o aic94xx: remove various inline functions
  o aic94xx: use bitops
  o aic94xx: remove queue comment
  o aic94xx: remove sas_common.c
  o aic94xx: sas remove depot's
  o aic94xx: use available list_for_each_entry_safe_reverse()
  o aic94xx: sas header file merge

James Bottomley:
  o aic94xx: fix TF_TMF_NO_CTX processing
  o aic94xx: convert to request_firmware interface
  o aic94xx: fix hotplug/unplug
  o aic94xx: add link error counts to the expander phys
  o aic94xx: add transport class phy reset capability
  o aic94xx: remove local_attached flag
  o Remove README
  o Fixup Makefile variable for libsas rename
  o Rename sas->libsas
  o aic94xx: correct return code for sas_discover_event
  o aic94xx: use parent backlink port
  o aic94xx: remove channel abstraction
  o aic94xx: fix routing algorithms
  o aic94xx: add backlink port
  o aic94xx: fix cascaded expander properties
  o aic94xx: fix sleep under lock
  o aic94xx: fix panic on module removal in complex topology
  o aic94xx: make use of the new sas_port
  o rename sas_port to asd_sas_port
  o Fix for eh_strategy_handler move
  o aic94xx: move entirely over to correct transport class formulation
  o remove last vestages of sas_rphy_alloc()
  o update for eh_timed_out move
  o Preliminary expander support for aic94xx
  o sas: remove event thread
  o minor warning cleanups
  o remove last vestiges of id mapping arrays
  o Further updates
  o Convert aic94xx over entirely to the transport class end device and
  o update aic94xx/sas to use the new sas transport class end device
  o [PATCH] aic94xx: attaching to the sas transport class
  o Add missing completion removal from prior patch
  o [PATCH] aic94xx: attaching to the sas transport class
  o Build fixes from akpm

Jeff Garzik:
  o [scsi aic94xx] Remove ->owner from PCI info table

Luben Tuikov:
  o initial aic94xx driver

Mike Anderson:
  o aic94xx: fix panic on module insertion
  o aic94xx: stub out SATA_DEV case
  o aic94xx: compile warning cleanups
  o aic94xx: sas_alloc_task
  o aic94xx: ref count update
  o aic94xx nexus loss time value
  o [PATCH] aic94xx: driver assertion in non-x86 BIOS env

Randy Dunlap:
  o libsas: externs not needed

Robert Tarte:
  o aic94xx: sequence patch - fixes SATA support

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 749 insertions, 0 deletions

diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
new file mode 100644
index 000000000000..d977bd492d8d
--- /dev/null
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -0,0 +1,749 @@
+/*
+ * Serial Attached SCSI (SAS) Discover process
+ *
+ * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
+ * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
+ *
+ * This file is licensed under GPLv2.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <linux/pci.h>
+#include <linux/scatterlist.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_eh.h>
+#include "sas_internal.h"
+
+#include <scsi/scsi_transport.h>
+#include <scsi/scsi_transport_sas.h>
+#include "../scsi_sas_internal.h"
+
+/* ---------- Basic task processing for discovery purposes ---------- */
+
+void sas_init_dev(struct domain_device *dev)
+{
+        INIT_LIST_HEAD(&dev->siblings);
+        INIT_LIST_HEAD(&dev->dev_list_node);
+        switch (dev->dev_type) {
+        case SAS_END_DEV:
+                break;
+        case EDGE_DEV:
+        case FANOUT_DEV:
+                INIT_LIST_HEAD(&dev->ex_dev.children);
+                break;
+        case SATA_DEV:
+        case SATA_PM:
+        case SATA_PM_PORT:
+                INIT_LIST_HEAD(&dev->sata_dev.children);
+                break;
+        default:
+                break;
+        }
+}
+
+static void sas_task_timedout(unsigned long _task)
+{
+	struct sas_task *task = (void *) _task;
+	unsigned long flags;
+
+	spin_lock_irqsave(&task->task_state_lock, flags);
+	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
+		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
+	spin_unlock_irqrestore(&task->task_state_lock, flags);
+
+	complete(&task->completion);
+}
+
+static void sas_disc_task_done(struct sas_task *task)
+{
+	if (!del_timer(&task->timer))
+		return;
+	complete(&task->completion);
+}
+
+#define SAS_DEV_TIMEOUT 10
+
+/**
+ * sas_execute_task -- Basic task processing for discovery
+ * @task: the task to be executed
+ * @buffer: pointer to buffer to do I/O
+ * @size: size of @buffer
+ * @pci_dma_dir: PCI_DMA_...
+ */
+static int sas_execute_task(struct sas_task *task, void *buffer, int size,
+			    int pci_dma_dir)
+{
+	int res = 0;
+	struct scatterlist *scatter = NULL;
+	struct task_status_struct *ts = &task->task_status;
+	int num_scatter = 0;
+	int retries = 0;
+	struct sas_internal *i =
+		to_sas_internal(task->dev->port->ha->core.shost->transportt);
+
+	if (pci_dma_dir != PCI_DMA_NONE) {
+		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
+		if (!scatter)
+			goto out;
+
+		sg_init_one(scatter, buffer, size);
+		num_scatter = 1;
+	}
+
+	task->task_proto = task->dev->tproto;
+	task->scatter = scatter;
+	task->num_scatter = num_scatter;
+	task->total_xfer_len = size;
+	task->data_dir = pci_dma_dir;
+	task->task_done = sas_disc_task_done;
+
+	for (retries = 0; retries < 5; retries++) {
+		task->task_state_flags = SAS_TASK_STATE_PENDING;
+		init_completion(&task->completion);
+
+		task->timer.data = (unsigned long) task;
+		task->timer.function = sas_task_timedout;
+		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
+		add_timer(&task->timer);
+
+		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
+		if (res) {
+			del_timer(&task->timer);
+			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
+				    res);
+			goto ex_err;
+		}
+		wait_for_completion(&task->completion);
+		res = -ETASK;
+		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
+			int res2;
+			SAS_DPRINTK("task aborted, flags:0x%x\n",
+				    task->task_state_flags);
+			res2 = i->dft->lldd_abort_task(task);
+			SAS_DPRINTK("came back from abort task\n");
+			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
+				if (res2 == TMF_RESP_FUNC_COMPLETE)
+					continue; /* Retry the task */
+				else
+					goto ex_err;
+			}
+		}
+		if (task->task_status.stat == SAM_BUSY ||
+			   task->task_status.stat == SAM_TASK_SET_FULL ||
+			   task->task_status.stat == SAS_QUEUE_FULL) {
+			SAS_DPRINTK("task: q busy, sleeping...\n");
+			schedule_timeout_interruptible(HZ);
+		} else if (task->task_status.stat == SAM_CHECK_COND) {
+			struct scsi_sense_hdr shdr;
+
+			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
+						  &shdr)) {
+				SAS_DPRINTK("couldn't normalize sense\n");
+				continue;
+			}
+			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
+			    (shdr.sense_key == 2 && shdr.asc == 4 &&
+			     shdr.ascq == 1)) {
+				SAS_DPRINTK("device %016llx LUN: %016llx "
+					    "powering up or not ready yet, "
+					    "sleeping...\n",
+					    SAS_ADDR(task->dev->sas_addr),
+					    SAS_ADDR(task->ssp_task.LUN));
+
+				schedule_timeout_interruptible(5*HZ);
+			} else if (shdr.sense_key == 1) {
+				res = 0;
+				break;
+			} else if (shdr.sense_key == 5) {
+				break;
+			} else {
+				SAS_DPRINTK("dev %016llx LUN: %016llx "
+					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
+					    "\n",
+					    SAS_ADDR(task->dev->sas_addr),
+					    SAS_ADDR(task->ssp_task.LUN),
+					    shdr.sense_key,
+					    shdr.asc, shdr.ascq);
+			}
+		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
+			   task->task_status.stat != SAM_GOOD) {
+			SAS_DPRINTK("task finished with resp:0x%x, "
+				    "stat:0x%x\n",
+				    task->task_status.resp,
+				    task->task_status.stat);
+			goto ex_err;
+		} else {
+			res = 0;
+			break;
+		}
+	}
+ex_err:
+	if (pci_dma_dir != PCI_DMA_NONE)
+		kfree(scatter);
+out:
+	return res;
+}
+
+/* ---------- Domain device discovery ---------- */
+
+/**
+ * sas_get_port_device -- Discover devices which caused port creation
+ * @port: pointer to struct sas_port of interest
+ *
+ * Devices directly attached to a HA port, have no parent.  This is
+ * how we know they are (domain) "root" devices.  All other devices
+ * do, and should have their "parent" pointer set appropriately as
+ * soon as a child device is discovered.
+ */
+static int sas_get_port_device(struct asd_sas_port *port)
+{
+	unsigned long flags;
+	struct asd_sas_phy *phy;
+	struct sas_rphy *rphy;
+	struct domain_device *dev;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&port->phy_list_lock, flags);
+	if (list_empty(&port->phy_list)) {
+		spin_unlock_irqrestore(&port->phy_list_lock, flags);
+		kfree(dev);
+		return -ENODEV;
+	}
+	phy = container_of(port->phy_list.next, struct asd_sas_phy, port_phy_el);
+	spin_lock(&phy->frame_rcvd_lock);
+	memcpy(dev->frame_rcvd, phy->frame_rcvd, min(sizeof(dev->frame_rcvd),
+					     (size_t)phy->frame_rcvd_size));
+	spin_unlock(&phy->frame_rcvd_lock);
+	spin_unlock_irqrestore(&port->phy_list_lock, flags);
+
+	if (dev->frame_rcvd[0] == 0x34 && port->oob_mode == SATA_OOB_MODE) {
+		struct dev_to_host_fis *fis =
+			(struct dev_to_host_fis *) dev->frame_rcvd;
+		if (fis->interrupt_reason == 1 && fis->lbal == 1 &&
+		    fis->byte_count_low==0x69 && fis->byte_count_high == 0x96
+		    && (fis->device & ~0x10) == 0)
+			dev->dev_type = SATA_PM;
+		else
+			dev->dev_type = SATA_DEV;
+		dev->tproto = SATA_PROTO;
+	} else {
+		struct sas_identify_frame *id =
+			(struct sas_identify_frame *) dev->frame_rcvd;
+		dev->dev_type = id->dev_type;
+		dev->iproto = id->initiator_bits;
+		dev->tproto = id->target_bits;
+	}
+
+	sas_init_dev(dev);
+
+	switch (dev->dev_type) {
+	case SAS_END_DEV:
+		rphy = sas_end_device_alloc(port->port);
+		break;
+	case EDGE_DEV:
+		rphy = sas_expander_alloc(port->port,
+					  SAS_EDGE_EXPANDER_DEVICE);
+		break;
+	case FANOUT_DEV:
+		rphy = sas_expander_alloc(port->port,
+					  SAS_FANOUT_EXPANDER_DEVICE);
+		break;
+	case SATA_DEV:
+	default:
+		printk("ERROR: Unidentified device type %d\n", dev->dev_type);
+		rphy = NULL;
+		break;
+	}
+
+	if (!rphy) {
+		kfree(dev);
+		return -ENODEV;
+	}
+	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
+	memcpy(dev->sas_addr, port->attached_sas_addr, SAS_ADDR_SIZE);
+	sas_fill_in_rphy(dev, rphy);
+	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
+	port->port_dev = dev;
+	dev->port = port;
+	dev->linkrate = port->linkrate;
+	dev->min_linkrate = port->linkrate;
+	dev->max_linkrate = port->linkrate;
+	dev->pathways = port->num_phys;
+	memset(port->disc.fanout_sas_addr, 0, SAS_ADDR_SIZE);
+	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
+	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
+	port->disc.max_level = 0;
+
+	dev->rphy = rphy;
+	spin_lock(&port->dev_list_lock);
+	list_add_tail(&dev->dev_list_node, &port->dev_list);
+	spin_unlock(&port->dev_list_lock);
+
+	return 0;
+}
+
+/* ---------- Discover and Revalidate ---------- */
+
+/* ---------- SATA ---------- */
+
+static void sas_get_ata_command_set(struct domain_device *dev)
+{
+	struct dev_to_host_fis *fis =
+		(struct dev_to_host_fis *) dev->frame_rcvd;
+
+	if ((fis->sector_count == 1 && /* ATA */
+	     fis->lbal         == 1 &&
+	     fis->lbam         == 0 &&
+	     fis->lbah         == 0 &&
+	     fis->device       == 0)
+	    ||
+	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
+	     fis->lbal         == 0 &&
+	     fis->lbam         == 0xCE &&
+	     fis->lbah         == 0xAA &&
+	     (fis->device & ~0x10) == 0))
+
+		dev->sata_dev.command_set = ATA_COMMAND_SET;
+
+	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
+		  fis->lbal             == 1 &&
+		  fis->byte_count_low   == 0x14 &&
+		  fis->byte_count_high  == 0xEB &&
+		  (fis->device & ~0x10) == 0))
+
+		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
+
+	else if ((fis->sector_count == 1 && /* SEMB */
+		  fis->lbal         == 1 &&
+		  fis->lbam         == 0x3C &&
+		  fis->lbah         == 0xC3 &&
+		  fis->device       == 0)
+		||
+		 (fis->interrupt_reason == 1 &&	/* SATA PM */
+		  fis->lbal             == 1 &&
+		  fis->byte_count_low   == 0x69 &&
+		  fis->byte_count_high  == 0x96 &&
+		  (fis->device & ~0x10) == 0))
+
+		/* Treat it as a superset? */
+		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
+}
+
+/**
+ * sas_issue_ata_cmd -- Basic SATA command processing for discovery
+ * @dev: the device to send the command to
+ * @command: the command register
+ * @features: the features register
+ * @buffer: pointer to buffer to do I/O
+ * @size: size of @buffer
+ * @pci_dma_dir: PCI_DMA_...
+ */
+static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
+			     u8 features, void *buffer, int size,
+			     int pci_dma_dir)
+{
+	int res = 0;
+	struct sas_task *task;
+	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
+		&dev->frame_rcvd[0];
+
+	res = -ENOMEM;
+	task = sas_alloc_task(GFP_KERNEL);
+	if (!task)
+		goto out;
+
+	task->dev = dev;
+
+	task->ata_task.fis.command = command;
+	task->ata_task.fis.features = features;
+	task->ata_task.fis.device = d2h_fis->device;
+	task->ata_task.retry_count = 1;
+
+	res = sas_execute_task(task, buffer, size, pci_dma_dir);
+
+	sas_free_task(task);
+out:
+	return res;
+}
+
+static void sas_sata_propagate_sas_addr(struct domain_device *dev)
+{
+	unsigned long flags;
+	struct asd_sas_port *port = dev->port;
+	struct asd_sas_phy  *phy;
+
+	BUG_ON(dev->parent);
+
+	memcpy(port->attached_sas_addr, dev->sas_addr, SAS_ADDR_SIZE);
+	spin_lock_irqsave(&port->phy_list_lock, flags);
+	list_for_each_entry(phy, &port->phy_list, port_phy_el)
+		memcpy(phy->attached_sas_addr, dev->sas_addr, SAS_ADDR_SIZE);
+	spin_unlock_irqrestore(&port->phy_list_lock, flags);
+}
+
+#define ATA_IDENTIFY_DEV         0xEC
+#define ATA_IDENTIFY_PACKET_DEV  0xA1
+#define ATA_SET_FEATURES         0xEF
+#define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
+
+/**
+ * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
+ * @dev: STP/SATA device of interest (ATA/ATAPI)
+ *
+ * The LLDD has already been notified of this device, so that we can
+ * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
+ * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
+ * performance for this device.
+ */
+static int sas_discover_sata_dev(struct domain_device *dev)
+{
+	int     res;
+	__le16  *identify_x;
+	u8      command;
+
+	identify_x = kzalloc(512, GFP_KERNEL);
+	if (!identify_x)
+		return -ENOMEM;
+
+	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
+		dev->sata_dev.identify_device = identify_x;
+		command = ATA_IDENTIFY_DEV;
+	} else {
+		dev->sata_dev.identify_packet_device = identify_x;
+		command = ATA_IDENTIFY_PACKET_DEV;
+	}
+
+	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
+				PCI_DMA_FROMDEVICE);
+	if (res)
+		goto out_err;
+
+	/* lives on the media? */
+	if (le16_to_cpu(identify_x[0]) & 4) {
+		/* incomplete response */
+		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
+			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
+		if (!le16_to_cpu(identify_x[83] & (1<<6)))
+			goto cont1;
+		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
+					ATA_FEATURE_PUP_STBY_SPIN_UP,
+					NULL, 0, PCI_DMA_NONE);
+		if (res)
+			goto cont1;
+
+		schedule_timeout_interruptible(5*HZ); /* More time? */
+		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
+					PCI_DMA_FROMDEVICE);
+		if (res)
+			goto out_err;
+	}
+cont1:
+	/* Get WWN */
+	if (dev->port->oob_mode != SATA_OOB_MODE) {
+		memcpy(dev->sas_addr, dev->sata_dev.rps_resp.rps.stp_sas_addr,
+		       SAS_ADDR_SIZE);
+	} else if (dev->sata_dev.command_set == ATA_COMMAND_SET &&
+		   (le16_to_cpu(dev->sata_dev.identify_device[108]) & 0xF000)
+		   == 0x5000) {
+		int i;
+
+		for (i = 0; i < 4; i++) {
+			dev->sas_addr[2*i] =
+	     (le16_to_cpu(dev->sata_dev.identify_device[108+i]) & 0xFF00) >> 8;
+			dev->sas_addr[2*i+1] =
+	      le16_to_cpu(dev->sata_dev.identify_device[108+i]) & 0x00FF;
+		}
+	}
+	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
+	if (!dev->parent)
+		sas_sata_propagate_sas_addr(dev);
+
+	/* XXX Hint: register this SATA device with SATL.
+	   When this returns, dev->sata_dev->lu is alive and
+	   present.
+	sas_satl_register_dev(dev);
+	*/
+	return 0;
+out_err:
+	dev->sata_dev.identify_packet_device = NULL;
+	dev->sata_dev.identify_device = NULL;
+	kfree(identify_x);
+	return res;
+}
+
+static int sas_discover_sata_pm(struct domain_device *dev)
+{
+	return -ENODEV;
+}
+
+int sas_notify_lldd_dev_found(struct domain_device *dev)
+{
+	int res = 0;
+	struct sas_ha_struct *sas_ha = dev->port->ha;
+	struct Scsi_Host *shost = sas_ha->core.shost;
+	struct sas_internal *i = to_sas_internal(shost->transportt);
+
+	if (i->dft->lldd_dev_found) {
+		res = i->dft->lldd_dev_found(dev);
+		if (res) {
+			printk("sas: driver on pcidev %s cannot handle "
+			       "device %llx, error:%d\n",
+			       pci_name(sas_ha->pcidev),
+			       SAS_ADDR(dev->sas_addr), res);
+		}
+	}
+	return res;
+}
+
+
+void sas_notify_lldd_dev_gone(struct domain_device *dev)
+{
+	struct sas_ha_struct *sas_ha = dev->port->ha;
+	struct Scsi_Host *shost = sas_ha->core.shost;
+	struct sas_internal *i = to_sas_internal(shost->transportt);
+
+	if (i->dft->lldd_dev_gone)
+		i->dft->lldd_dev_gone(dev);
+}
+
+/* ---------- Common/dispatchers ---------- */
+
+/**
+ * sas_discover_sata -- discover an STP/SATA domain device
+ * @dev: pointer to struct domain_device of interest
+ *
+ * First we notify the LLDD of this device, so we can send frames to
+ * it.  Then depending on the type of device we call the appropriate
+ * discover functions.  Once device discover is done, we notify the
+ * LLDD so that it can fine-tune its parameters for the device, by
+ * removing it and then adding it.  That is, the second time around,
+ * the driver would have certain fields, that it is looking at, set.
+ * Finally we initialize the kobj so that the device can be added to
+ * the system at registration time.  Devices directly attached to a HA
+ * port, have no parents.  All other devices do, and should have their
+ * "parent" pointer set appropriately before calling this function.
+ */
+int sas_discover_sata(struct domain_device *dev)
+{
+	int res;
+
+	sas_get_ata_command_set(dev);
+
+	res = sas_notify_lldd_dev_found(dev);
+	if (res)
+		return res;
+
+	switch (dev->dev_type) {
+	case SATA_DEV:
+		res = sas_discover_sata_dev(dev);
+		break;
+	case SATA_PM:
+		res = sas_discover_sata_pm(dev);
+		break;
+	default:
+		break;
+	}
+
+	sas_notify_lldd_dev_gone(dev);
+	if (!res) {
+		sas_notify_lldd_dev_found(dev);
+	}
+	return res;
+}
+
+/**
+ * sas_discover_end_dev -- discover an end device (SSP, etc)
+ * @end: pointer to domain device of interest
+ *
+ * See comment in sas_discover_sata().
+ */
+int sas_discover_end_dev(struct domain_device *dev)
+{
+	int res;
+
+	res = sas_notify_lldd_dev_found(dev);
+	if (res)
+		return res;
+
+	res = sas_rphy_add(dev->rphy);
+	if (res)
+		goto out_err;
+
+	/* do this to get the end device port attributes which will have
+	 * been scanned in sas_rphy_add */
+	sas_notify_lldd_dev_gone(dev);
+	sas_notify_lldd_dev_found(dev);
+
+	return 0;
+
+out_err:
+	sas_notify_lldd_dev_gone(dev);
+	return res;
+}
+
+/* ---------- Device registration and unregistration ---------- */
+
+static inline void sas_unregister_common_dev(struct domain_device *dev)
+{
+	sas_notify_lldd_dev_gone(dev);
+	if (!dev->parent)
+		dev->port->port_dev = NULL;
+	else
+		list_del_init(&dev->siblings);
+	list_del_init(&dev->dev_list_node);
+}
+
+void sas_unregister_dev(struct domain_device *dev)
+{
+	if (dev->rphy) {
+		sas_remove_children(&dev->rphy->dev);
+		sas_rphy_delete(dev->rphy);
+		dev->rphy = NULL;
+	}
+	if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV) {
+		/* remove the phys and ports, everything else should be gone */
+		kfree(dev->ex_dev.ex_phy);
+		dev->ex_dev.ex_phy = NULL;
+	}
+	sas_unregister_common_dev(dev);
+}
+
+void sas_unregister_domain_devices(struct asd_sas_port *port)
+{
+	struct domain_device *dev, *n;
+
+	list_for_each_entry_safe_reverse(dev,n,&port->dev_list,dev_list_node)
+		sas_unregister_dev(dev);
+
+	port->port->rphy = NULL;
+
+}
+
+/* ---------- Discovery and Revalidation ---------- */
+
+/**
+ * sas_discover_domain -- discover the domain
+ * @port: port to the domain of interest
+ *
+ * NOTE: this process _must_ quit (return) as soon as any connection
+ * errors are encountered.  Connection recovery is done elsewhere.
+ * Discover process only interrogates devices in order to discover the
+ * domain.
+ */
+static void sas_discover_domain(void *data)
+{
+	int error = 0;
+	struct asd_sas_port *port = data;
+
+	sas_begin_event(DISCE_DISCOVER_DOMAIN, &port->disc.disc_event_lock,
+			&port->disc.pending);
+
+	if (port->port_dev)
+		return ;
+	else {
+		error = sas_get_port_device(port);
+		if (error)
+			return;
+	}
+
+	SAS_DPRINTK("DOING DISCOVERY on port %d, pid:%d\n", port->id,
+		    current->pid);
+
+	switch (port->port_dev->dev_type) {
+	case SAS_END_DEV:
+		error = sas_discover_end_dev(port->port_dev);
+		break;
+	case EDGE_DEV:
+	case FANOUT_DEV:
+		error = sas_discover_root_expander(port->port_dev);
+		break;
+	case SATA_DEV:
+	case SATA_PM:
+		error = sas_discover_sata(port->port_dev);
+		break;
+	default:
+		SAS_DPRINTK("unhandled device %d\n", port->port_dev->dev_type);
+		break;
+	}
+
+	if (error) {
+		kfree(port->port_dev); /* not kobject_register-ed yet */
+		port->port_dev = NULL;
+	}
+
+	SAS_DPRINTK("DONE DISCOVERY on port %d, pid:%d, result:%d\n", port->id,
+		    current->pid, error);
+}
+
+static void sas_revalidate_domain(void *data)
+{
+	int res = 0;
+	struct asd_sas_port *port = data;
+
+	sas_begin_event(DISCE_REVALIDATE_DOMAIN, &port->disc.disc_event_lock,
+			&port->disc.pending);
+
+	SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
+		    current->pid);
+	if (port->port_dev)
+		res = sas_ex_revalidate_domain(port->port_dev);
+
+	SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
+		    port->id, current->pid, res);
+}
+
+/* ---------- Events ---------- */
+
+int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
+{
+	struct sas_discovery *disc;
+
+	if (!port)
+		return 0;
+	disc = &port->disc;
+
+	BUG_ON(ev >= DISC_NUM_EVENTS);
+
+	sas_queue_event(ev, &disc->disc_event_lock, &disc->pending,
+			&disc->disc_work[ev], port->ha->core.shost);
+
+	return 0;
+}
+
+/**
+ * sas_init_disc -- initialize the discovery struct in the port
+ * @port: pointer to struct port
+ *
+ * Called when the ports are being initialized.
+ */
+void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
+{
+	int i;
+
+	static void (*sas_event_fns[DISC_NUM_EVENTS])(void *) = {
+		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
+		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
+	};
+
+	spin_lock_init(&disc->disc_event_lock);
+	disc->pending = 0;
+	for (i = 0; i < DISC_NUM_EVENTS; i++)
+		INIT_WORK(&disc->disc_work[i], sas_event_fns[i], port);
+}