text: /*
   *  linux/drivers/scsi/esas2r/esas2r_disc.c
   *      esas2r device discovery routines
   *
   *  Copyright (c) 2001-2013 ATTO Technology, Inc.
   *  (mailto:linuxdrivers@attotech.com)
   */
  /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
  /*
   *  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; version 2 of the License.
   *
   *  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.
   *
   *  NO WARRANTY
   *  THE PROGRAM IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OR
   *  CONDITIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED INCLUDING, WITHOUT
   *  LIMITATION, ANY WARRANTIES OR CONDITIONS OF TITLE, NON-INFRINGEMENT,
   *  MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Each Recipient is
   *  solely responsible for determining the appropriateness of using and
   *  distributing the Program and assumes all risks associated with its
   *  exercise of rights under this Agreement, including but not limited to
   *  the risks and costs of program errors, damage to or loss of data,
   *  programs or equipment, and unavailability or interruption of operations.
   *
   *  DISCLAIMER OF LIABILITY
   *  NEITHER RECIPIENT NOR ANY CONTRIBUTORS SHALL HAVE ANY LIABILITY FOR ANY
   *  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   *  DAMAGES (INCLUDING WITHOUT LIMITATION LOST PROFITS), HOWEVER CAUSED AND
   *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
   *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
   *  USE OR DISTRIBUTION OF THE PROGRAM OR THE EXERCISE OF ANY RIGHTS GRANTED
   *  HEREUNDER, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES
   *
   *  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
  
  #include "esas2r.h"
  
  /* Miscellaneous internal discovery routines */
  static void esas2r_disc_abort(struct esas2r_adapter *a,
  			      struct esas2r_request *rq);
  static bool esas2r_disc_continue(struct esas2r_adapter *a,
  				 struct esas2r_request *rq);
  static void esas2r_disc_fix_curr_requests(struct esas2r_adapter *a);
  static u32 esas2r_disc_get_phys_addr(struct esas2r_sg_context *sgc, u64 *addr);
  static bool esas2r_disc_start_request(struct esas2r_adapter *a,
  				      struct esas2r_request *rq);
  
  /* Internal discovery routines that process the states */
  static bool esas2r_disc_block_dev_scan(struct esas2r_adapter *a,
  				       struct esas2r_request *rq);
  static void esas2r_disc_block_dev_scan_cb(struct esas2r_adapter *a,
  					  struct esas2r_request *rq);
  static bool esas2r_disc_dev_add(struct esas2r_adapter *a,
  				struct esas2r_request *rq);
  static bool esas2r_disc_dev_remove(struct esas2r_adapter *a,
  				   struct esas2r_request *rq);
  static bool esas2r_disc_part_info(struct esas2r_adapter *a,
  				  struct esas2r_request *rq);
  static void esas2r_disc_part_info_cb(struct esas2r_adapter *a,
  				     struct esas2r_request *rq);
  static bool esas2r_disc_passthru_dev_info(struct esas2r_adapter *a,
  					  struct esas2r_request *rq);
  static void esas2r_disc_passthru_dev_info_cb(struct esas2r_adapter *a,
  					     struct esas2r_request *rq);
  static bool esas2r_disc_passthru_dev_addr(struct esas2r_adapter *a,
  					  struct esas2r_request *rq);
  static void esas2r_disc_passthru_dev_addr_cb(struct esas2r_adapter *a,
  					     struct esas2r_request *rq);
  static bool esas2r_disc_raid_grp_info(struct esas2r_adapter *a,
  				      struct esas2r_request *rq);
  static void esas2r_disc_raid_grp_info_cb(struct esas2r_adapter *a,
  					 struct esas2r_request *rq);
  
  void esas2r_disc_initialize(struct esas2r_adapter *a)
  {
  	struct esas2r_sas_nvram *nvr = a->nvram;
  
  	esas2r_trace_enter();
  
  	clear_bit(AF_DISC_IN_PROG, &a->flags);
  	clear_bit(AF2_DEV_SCAN, &a->flags2);
  	clear_bit(AF2_DEV_CNT_OK, &a->flags2);
  
  	a->disc_start_time = jiffies_to_msecs(jiffies);
  	a->disc_wait_time = nvr->dev_wait_time * 1000;
  	a->disc_wait_cnt = nvr->dev_wait_count;
  
  	if (a->disc_wait_cnt > ESAS2R_MAX_TARGETS)
  		a->disc_wait_cnt = ESAS2R_MAX_TARGETS;
  
  	/*
  	 * If we are doing chip reset or power management processing, always
  	 * wait for devices.  use the NVRAM device count if it is greater than
  	 * previously discovered devices.
  	 */
  
  	esas2r_hdebug("starting discovery...");
  
  	a->general_req.interrupt_cx = NULL;
  
  	if (test_bit(AF_CHPRST_DETECTED, &a->flags) ||
  	    test_bit(AF_POWER_MGT, &a->flags)) {
  		if (a->prev_dev_cnt == 0) {
  			/* Don't bother waiting if there is nothing to wait
  			 * for.
  			 */
  			a->disc_wait_time = 0;
  		} else {
  			/*
  			 * Set the device wait count to what was previously
  			 * found.  We don't care if the user only configured
  			 * a time because we know the exact count to wait for.
  			 * There is no need to honor the user's wishes to
  			 * always wait the full time.
  			 */
  			a->disc_wait_cnt = a->prev_dev_cnt;
  
  			/*
  			 * bump the minimum wait time to 15 seconds since the
  			 * default is 3 (system boot or the boot driver usually
  			 * buys us more time).
  			 */
  			if (a->disc_wait_time < 15000)
  				a->disc_wait_time = 15000;
  		}
  	}
  
  	esas2r_trace("disc wait count: %d", a->disc_wait_cnt);
  	esas2r_trace("disc wait time: %d", a->disc_wait_time);
  
  	if (a->disc_wait_time == 0)
  		esas2r_disc_check_complete(a);
  
  	esas2r_trace_exit();
  }
  
  void esas2r_disc_start_waiting(struct esas2r_adapter *a)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&a->mem_lock, flags);
  
  	if (a->disc_ctx.disc_evt)
  		esas2r_disc_start_port(a);
  
  	spin_unlock_irqrestore(&a->mem_lock, flags);
  }
  
  void esas2r_disc_check_for_work(struct esas2r_adapter *a)
  {
  	struct esas2r_request *rq = &a->general_req;
  
  	/* service any pending interrupts first */
  
  	esas2r_polled_interrupt(a);
  
  	/*
  	 * now, interrupt processing may have queued up a discovery event.  go
  	 * see if we have one to start.  we couldn't start it in the ISR since
  	 * polled discovery would cause a deadlock.
  	 */
  
  	esas2r_disc_start_waiting(a);
  
  	if (rq->interrupt_cx == NULL)
  		return;
  
  	if (rq->req_stat == RS_STARTED
  	    && rq->timeout <= RQ_MAX_TIMEOUT) {
  		/* wait for the current discovery request to complete. */
  		esas2r_wait_request(a, rq);
  
  		if (rq->req_stat == RS_TIMEOUT) {
  			esas2r_disc_abort(a, rq);
  			esas2r_local_reset_adapter(a);
  			return;
  		}
  	}
  
  	if (rq->req_stat == RS_PENDING
  	    || rq->req_stat == RS_STARTED)
  		return;
  
  	esas2r_disc_continue(a, rq);
  }
  
  void esas2r_disc_check_complete(struct esas2r_adapter *a)
  {
  	unsigned long flags;
  
  	esas2r_trace_enter();
  
  	/* check to see if we should be waiting for devices */
  	if (a->disc_wait_time) {
  		u32 currtime = jiffies_to_msecs(jiffies);
  		u32 time = currtime - a->disc_start_time;
  
  		/*
  		 * Wait until the device wait time is exhausted or the device
  		 * wait count is satisfied.
  		 */
  		if (time < a->disc_wait_time
  		    && (esas2r_targ_db_get_tgt_cnt(a) < a->disc_wait_cnt
  			|| a->disc_wait_cnt == 0)) {
  			/* After three seconds of waiting, schedule a scan. */
  			if (time >= 3000
  			    && !test_and_set_bit(AF2_DEV_SCAN, &a->flags2)) {
  				spin_lock_irqsave(&a->mem_lock, flags);
  				esas2r_disc_queue_event(a, DCDE_DEV_SCAN);
  				spin_unlock_irqrestore(&a->mem_lock, flags);
  			}
  
  			esas2r_trace_exit();
  			return;
  		}
  
  		/*
  		 * We are done waiting...we think.  Adjust the wait time to
  		 * consume events after the count is met.
  		 */
  		if (!test_and_set_bit(AF2_DEV_CNT_OK, &a->flags2))
  			a->disc_wait_time = time + 3000;
  
  		/* If we haven't done a full scan yet, do it now. */
  		if (!test_and_set_bit(AF2_DEV_SCAN, &a->flags2)) {
  			spin_lock_irqsave(&a->mem_lock, flags);
  			esas2r_disc_queue_event(a, DCDE_DEV_SCAN);
  			spin_unlock_irqrestore(&a->mem_lock, flags);
  			esas2r_trace_exit();
  			return;
  		}
  
  		/*
  		 * Now, if there is still time left to consume events, continue
  		 * waiting.
  		 */
  		if (time < a->disc_wait_time) {
  			esas2r_trace_exit();
  			return;
  		}
  	} else {
  		if (!test_and_set_bit(AF2_DEV_SCAN, &a->flags2)) {
  			spin_lock_irqsave(&a->mem_lock, flags);
  			esas2r_disc_queue_event(a, DCDE_DEV_SCAN);
  			spin_unlock_irqrestore(&a->mem_lock, flags);
  		}
  	}
  
  	/* We want to stop waiting for devices. */
  	a->disc_wait_time = 0;
  
  	if (test_bit(AF_DISC_POLLED, &a->flags) &&
  	    test_bit(AF_DISC_IN_PROG, &a->flags)) {
  		/*
  		 * Polled discovery is still pending so continue the active
  		 * discovery until it is done.  At that point, we will stop
  		 * polled discovery and transition to interrupt driven
  		 * discovery.
  		 */
  	} else {
  		/*
  		 * Done waiting for devices.  Note that we get here immediately
  		 * after deferred waiting completes because that is interrupt
  		 * driven; i.e. There is no transition.
  		 */
  		esas2r_disc_fix_curr_requests(a);
  		clear_bit(AF_DISC_PENDING, &a->flags);
  
  		/*
  		 * We have deferred target state changes until now because we
  		 * don't want to report any removals (due to the first arrival)
  		 * until the device wait time expires.
  		 */
  		set_bit(AF_PORT_CHANGE, &a->flags);
  	}
  
  	esas2r_trace_exit();
  }
  
  void esas2r_disc_queue_event(struct esas2r_adapter *a, u8 disc_evt)
  {
  	struct esas2r_disc_context *dc = &a->disc_ctx;
  
  	esas2r_trace_enter();
  
  	esas2r_trace("disc_event: %d", disc_evt);
  
  	/* Initialize the discovery context */
  	dc->disc_evt |= disc_evt;
  
  	/*
  	 * Don't start discovery before or during polled discovery.  if we did,
  	 * we would have a deadlock if we are in the ISR already.
  	 */
  	if (!test_bit(AF_CHPRST_PENDING, &a->flags) &&
  	    !test_bit(AF_DISC_POLLED, &a->flags))
  		esas2r_disc_start_port(a);
  
  	esas2r_trace_exit();
  }
  
  bool esas2r_disc_start_port(struct esas2r_adapter *a)
  {
  	struct esas2r_request *rq = &a->general_req;
  	struct esas2r_disc_context *dc = &a->disc_ctx;
  	bool ret;
  
  	esas2r_trace_enter();
  
  	if (test_bit(AF_DISC_IN_PROG, &a->flags)) {
  		esas2r_trace_exit();
  
  		return false;
  	}
  
  	/* If there is a discovery waiting, process it. */
  	if (dc->disc_evt) {
  		if (test_bit(AF_DISC_POLLED, &a->flags)
  		    && a->disc_wait_time == 0) {
  			/*
  			 * We are doing polled discovery, but we no longer want
  			 * to wait for devices.  Stop polled discovery and
  			 * transition to interrupt driven discovery.
  			 */
  
  			esas2r_trace_exit();
  
  			return false;
  		}
  	} else {
  		/* Discovery is complete. */
  
  		esas2r_hdebug("disc done");
  
  		set_bit(AF_PORT_CHANGE, &a->flags);
  
  		esas2r_trace_exit();
  
  		return false;
  	}
  
  	/* Handle the discovery context */
  	esas2r_trace("disc_evt: %d", dc->disc_evt);
  	set_bit(AF_DISC_IN_PROG, &a->flags);
  	dc->flags = 0;
  
  	if (test_bit(AF_DISC_POLLED, &a->flags))
  		dc->flags |= DCF_POLLED;
  
  	rq->interrupt_cx = dc;
  	rq->req_stat = RS_SUCCESS;
  
  	/* Decode the event code */
  	if (dc->disc_evt & DCDE_DEV_SCAN) {
  		dc->disc_evt &= ~DCDE_DEV_SCAN;
  
  		dc->flags |= DCF_DEV_SCAN;
  		dc->state = DCS_BLOCK_DEV_SCAN;
  	} else if (dc->disc_evt & DCDE_DEV_CHANGE) {
  		dc->disc_evt &= ~DCDE_DEV_CHANGE;
  
  		dc->flags |= DCF_DEV_CHANGE;
  		dc->state = DCS_DEV_RMV;
  	}
  
  	/* Continue interrupt driven discovery */
  	if (!test_bit(AF_DISC_POLLED, &a->flags))
  		ret = esas2r_disc_continue(a, rq);
  	else
  		ret = true;
  
  	esas2r_trace_exit();
  
  	return ret;
  }
  
  static bool esas2r_disc_continue(struct esas2r_adapter *a,
  				 struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	bool rslt;
  
  	/* Device discovery/removal */
  	while (dc->flags & (DCF_DEV_CHANGE | DCF_DEV_SCAN)) {
  		rslt = false;
  
  		switch (dc->state) {
  		case DCS_DEV_RMV:
  
  			rslt = esas2r_disc_dev_remove(a, rq);
  			break;
  
  		case DCS_DEV_ADD:
  
  			rslt = esas2r_disc_dev_add(a, rq);
  			break;
  
  		case DCS_BLOCK_DEV_SCAN:
  
  			rslt = esas2r_disc_block_dev_scan(a, rq);
  			break;
  
  		case DCS_RAID_GRP_INFO:
  
  			rslt = esas2r_disc_raid_grp_info(a, rq);
  			break;
  
  		case DCS_PART_INFO:
  
  			rslt = esas2r_disc_part_info(a, rq);
  			break;
  
  		case DCS_PT_DEV_INFO:
  
  			rslt = esas2r_disc_passthru_dev_info(a, rq);
  			break;
  		case DCS_PT_DEV_ADDR:
  
  			rslt = esas2r_disc_passthru_dev_addr(a, rq);
  			break;
  		case DCS_DISC_DONE:
  
  			dc->flags &= ~(DCF_DEV_CHANGE | DCF_DEV_SCAN);
  			break;
  
  		default:
  
  			esas2r_bugon();
  			dc->state = DCS_DISC_DONE;
  			break;
  		}
  
  		if (rslt)
  			return true;
  	}
  
  	/* Discovery is done...for now. */
  	rq->interrupt_cx = NULL;
  
  	if (!test_bit(AF_DISC_PENDING, &a->flags))
  		esas2r_disc_fix_curr_requests(a);
  
  	clear_bit(AF_DISC_IN_PROG, &a->flags);
  
  	/* Start the next discovery. */
  	return esas2r_disc_start_port(a);
  }
  
  static bool esas2r_disc_start_request(struct esas2r_adapter *a,
  				      struct esas2r_request *rq)
  {
  	unsigned long flags;
  
  	/* Set the timeout to a minimum value. */
  	if (rq->timeout < ESAS2R_DEFAULT_TMO)
  		rq->timeout = ESAS2R_DEFAULT_TMO;
  
  	/*
  	 * Override the request type to distinguish discovery requests.  If we
  	 * end up deferring the request, esas2r_disc_local_start_request()
  	 * will be called to restart it.
  	 */
  	rq->req_type = RT_DISC_REQ;
  
  	spin_lock_irqsave(&a->queue_lock, flags);
  
  	if (!test_bit(AF_CHPRST_PENDING, &a->flags) &&
  	    !test_bit(AF_FLASHING, &a->flags))
  		esas2r_disc_local_start_request(a, rq);
  	else
  		list_add_tail(&rq->req_list, &a->defer_list);
  
  	spin_unlock_irqrestore(&a->queue_lock, flags);
  
  	return true;
  }
  
  void esas2r_disc_local_start_request(struct esas2r_adapter *a,
  				     struct esas2r_request *rq)
  {
  	esas2r_trace_enter();
  
  	list_add_tail(&rq->req_list, &a->active_list);
  
  	esas2r_start_vda_request(a, rq);
  
  	esas2r_trace_exit();
  
  	return;
  }
  
  static void esas2r_disc_abort(struct esas2r_adapter *a,
  			      struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  
  	esas2r_trace_enter();
  
  	/* abort the current discovery */
  
  	dc->state = DCS_DISC_DONE;
  
  	esas2r_trace_exit();
  }
  
  static bool esas2r_disc_block_dev_scan(struct esas2r_adapter *a,
  				       struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	bool rslt;
  
  	esas2r_trace_enter();
  
  	esas2r_rq_init_request(rq, a);
  
  	esas2r_build_mgt_req(a,
  			     rq,
  			     VDAMGT_DEV_SCAN,
  			     0,
  			     0,
  			     0,
  			     NULL);
  
  	rq->comp_cb = esas2r_disc_block_dev_scan_cb;
  
  	rq->timeout = 30000;
  	rq->interrupt_cx = dc;
  
  	rslt = esas2r_disc_start_request(a, rq);
  
  	esas2r_trace_exit();
  
  	return rslt;
  }
  
  static void esas2r_disc_block_dev_scan_cb(struct esas2r_adapter *a,
  					  struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	unsigned long flags;
  
  	esas2r_trace_enter();
  
  	spin_lock_irqsave(&a->mem_lock, flags);
  
  	if (rq->req_stat == RS_SUCCESS)
  		dc->scan_gen = rq->func_rsp.mgt_rsp.scan_generation;
  
  	dc->state = DCS_RAID_GRP_INFO;
  	dc->raid_grp_ix = 0;
  
  	esas2r_rq_destroy_request(rq, a);
  
  	/* continue discovery if it's interrupt driven */
  
  	if (!(dc->flags & DCF_POLLED))
  		esas2r_disc_continue(a, rq);
  
  	spin_unlock_irqrestore(&a->mem_lock, flags);
  
  	esas2r_trace_exit();
  }
  
  static bool esas2r_disc_raid_grp_info(struct esas2r_adapter *a,
  				      struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	bool rslt;
  	struct atto_vda_grp_info *grpinfo;
  
  	esas2r_trace_enter();
  
  	esas2r_trace("raid_group_idx: %d", dc->raid_grp_ix);
  
  	if (dc->raid_grp_ix >= VDA_MAX_RAID_GROUPS) {
  		dc->state = DCS_DISC_DONE;
  
  		esas2r_trace_exit();
  
  		return false;
  	}
  
  	esas2r_rq_init_request(rq, a);
  
  	grpinfo = &rq->vda_rsp_data->mgt_data.data.grp_info;
  
  	memset(grpinfo, 0, sizeof(struct atto_vda_grp_info));
  
  	esas2r_build_mgt_req(a,
  			     rq,
  			     VDAMGT_GRP_INFO,
  			     dc->scan_gen,
  			     0,
  			     sizeof(struct atto_vda_grp_info),
  			     NULL);
  
  	grpinfo->grp_index = dc->raid_grp_ix;
  
  	rq->comp_cb = esas2r_disc_raid_grp_info_cb;
  
  	rq->interrupt_cx = dc;
  
  	rslt = esas2r_disc_start_request(a, rq);
  
  	esas2r_trace_exit();
  
  	return rslt;
  }
  
  static void esas2r_disc_raid_grp_info_cb(struct esas2r_adapter *a,
  					 struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	unsigned long flags;
  	struct atto_vda_grp_info *grpinfo;
  
  	esas2r_trace_enter();
  
  	spin_lock_irqsave(&a->mem_lock, flags);
  
  	if (rq->req_stat == RS_SCAN_GEN) {
  		dc->scan_gen = rq->func_rsp.mgt_rsp.scan_generation;
  		dc->raid_grp_ix = 0;
  		goto done;
  	}
  
  	if (rq->req_stat == RS_SUCCESS) {
  		grpinfo = &rq->vda_rsp_data->mgt_data.data.grp_info;
  
  		if (grpinfo->status != VDA_GRP_STAT_ONLINE
  		    && grpinfo->status != VDA_GRP_STAT_DEGRADED) {
  			/* go to the next group. */
  
  			dc->raid_grp_ix++;
  		} else {
  			memcpy(&dc->raid_grp_name[0],
  			       &grpinfo->grp_name[0],
  			       sizeof(grpinfo->grp_name));
  
  			dc->interleave = le32_to_cpu(grpinfo->interleave);
  			dc->block_size = le32_to_cpu(grpinfo->block_size);
  
  			dc->state = DCS_PART_INFO;
  			dc->part_num = 0;
  		}
  	} else {
  		if (!(rq->req_stat == RS_GRP_INVALID)) {
  			esas2r_log(ESAS2R_LOG_WARN,
  				   "A request for RAID group info failed - "
  				   "returned with %x",
  				   rq->req_stat);
  		}
  
  		dc->dev_ix = 0;
  		dc->state = DCS_PT_DEV_INFO;
  	}
  
  done:
  
  	esas2r_rq_destroy_request(rq, a);
  
  	/* continue discovery if it's interrupt driven */
  
  	if (!(dc->flags & DCF_POLLED))
  		esas2r_disc_continue(a, rq);
  
  	spin_unlock_irqrestore(&a->mem_lock, flags);
  
  	esas2r_trace_exit();
  }
  
  static bool esas2r_disc_part_info(struct esas2r_adapter *a,
  				  struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	bool rslt;
  	struct atto_vdapart_info *partinfo;
  
  	esas2r_trace_enter();
  
  	esas2r_trace("part_num: %d", dc->part_num);
  
  	if (dc->part_num >= VDA_MAX_PARTITIONS) {
  		dc->state = DCS_RAID_GRP_INFO;
  		dc->raid_grp_ix++;
  
  		esas2r_trace_exit();
  
  		return false;
  	}
  
  	esas2r_rq_init_request(rq, a);
  
  	partinfo = &rq->vda_rsp_data->mgt_data.data.part_info;
  
  	memset(partinfo, 0, sizeof(struct atto_vdapart_info));
  
  	esas2r_build_mgt_req(a,
  			     rq,
  			     VDAMGT_PART_INFO,
  			     dc->scan_gen,
  			     0,
  			     sizeof(struct atto_vdapart_info),
  			     NULL);
  
  	partinfo->part_no = dc->part_num;
  
  	memcpy(&partinfo->grp_name[0],
  	       &dc->raid_grp_name[0],
  	       sizeof(partinfo->grp_name));
  
  	rq->comp_cb = esas2r_disc_part_info_cb;
  
  	rq->interrupt_cx = dc;
  
  	rslt = esas2r_disc_start_request(a, rq);
  
  	esas2r_trace_exit();
  
  	return rslt;
  }
  
  static void esas2r_disc_part_info_cb(struct esas2r_adapter *a,
  				     struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	unsigned long flags;
  	struct atto_vdapart_info *partinfo;
  
  	esas2r_trace_enter();
  
  	spin_lock_irqsave(&a->mem_lock, flags);
  
  	if (rq->req_stat == RS_SCAN_GEN) {
  		dc->scan_gen = rq->func_rsp.mgt_rsp.scan_generation;
  		dc->raid_grp_ix = 0;
  		dc->state = DCS_RAID_GRP_INFO;
  	} else if (rq->req_stat == RS_SUCCESS) {
  		partinfo = &rq->vda_rsp_data->mgt_data.data.part_info;
  
  		dc->part_num = partinfo->part_no;
  
  		dc->curr_virt_id = le16_to_cpu(partinfo->target_id);
  
  		esas2r_targ_db_add_raid(a, dc);
  
  		dc->part_num++;
  	} else {
  		if (!(rq->req_stat == RS_PART_LAST)) {
  			esas2r_log(ESAS2R_LOG_WARN,
  				   "A request for RAID group partition info "
  				   "failed - status:%d", rq->req_stat);
  		}
  
  		dc->state = DCS_RAID_GRP_INFO;
  		dc->raid_grp_ix++;
  	}
  
  	esas2r_rq_destroy_request(rq, a);
  
  	/* continue discovery if it's interrupt driven */
  
  	if (!(dc->flags & DCF_POLLED))
  		esas2r_disc_continue(a, rq);
  
  	spin_unlock_irqrestore(&a->mem_lock, flags);
  
  	esas2r_trace_exit();
  }
  
  static bool esas2r_disc_passthru_dev_info(struct esas2r_adapter *a,
  					  struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	bool rslt;
  	struct atto_vda_devinfo *devinfo;
  
  	esas2r_trace_enter();
  
  	esas2r_trace("dev_ix: %d", dc->dev_ix);
  
  	esas2r_rq_init_request(rq, a);
  
  	devinfo = &rq->vda_rsp_data->mgt_data.data.dev_info;
  
  	memset(devinfo, 0, sizeof(struct atto_vda_devinfo));
  
  	esas2r_build_mgt_req(a,
  			     rq,
  			     VDAMGT_DEV_PT_INFO,
  			     dc->scan_gen,
  			     dc->dev_ix,
  			     sizeof(struct atto_vda_devinfo),
  			     NULL);
  
  	rq->comp_cb = esas2r_disc_passthru_dev_info_cb;
  
  	rq->interrupt_cx = dc;
  
  	rslt = esas2r_disc_start_request(a, rq);
  
  	esas2r_trace_exit();
  
  	return rslt;
  }
  
  static void esas2r_disc_passthru_dev_info_cb(struct esas2r_adapter *a,
  					     struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	unsigned long flags;
  	struct atto_vda_devinfo *devinfo;
  
  	esas2r_trace_enter();
  
  	spin_lock_irqsave(&a->mem_lock, flags);
  
  	if (rq->req_stat == RS_SCAN_GEN) {
  		dc->scan_gen = rq->func_rsp.mgt_rsp.scan_generation;
  		dc->dev_ix = 0;
  		dc->state = DCS_PT_DEV_INFO;
  	} else if (rq->req_stat == RS_SUCCESS) {
  		devinfo = &rq->vda_rsp_data->mgt_data.data.dev_info;
  
  		dc->dev_ix = le16_to_cpu(rq->func_rsp.mgt_rsp.dev_index);
  
  		dc->curr_virt_id = le16_to_cpu(devinfo->target_id);
  
  		if (le16_to_cpu(devinfo->features) & VDADEVFEAT_PHYS_ID) {
  			dc->curr_phys_id =
  				le16_to_cpu(devinfo->phys_target_id);
  			dc->dev_addr_type = ATTO_GDA_AT_PORT;
  			dc->state = DCS_PT_DEV_ADDR;
  
  			esas2r_trace("curr_virt_id: %d", dc->curr_virt_id);
  			esas2r_trace("curr_phys_id: %d", dc->curr_phys_id);
  		} else {
  			dc->dev_ix++;
  		}
  	} else {
  		if (!(rq->req_stat == RS_DEV_INVALID)) {
  			esas2r_log(ESAS2R_LOG_WARN,
  				   "A request for device information failed - "
  				   "status:%d", rq->req_stat);
  		}
  
  		dc->state = DCS_DISC_DONE;
  	}
  
  	esas2r_rq_destroy_request(rq, a);
  
  	/* continue discovery if it's interrupt driven */
  
  	if (!(dc->flags & DCF_POLLED))
  		esas2r_disc_continue(a, rq);
  
  	spin_unlock_irqrestore(&a->mem_lock, flags);
  
  	esas2r_trace_exit();
  }
  
  static bool esas2r_disc_passthru_dev_addr(struct esas2r_adapter *a,
  					  struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	bool rslt;
  	struct atto_ioctl *hi;
  	struct esas2r_sg_context sgc;
  
  	esas2r_trace_enter();
  
  	esas2r_rq_init_request(rq, a);
  
  	/* format the request. */
  
  	sgc.cur_offset = NULL;
  	sgc.get_phys_addr = (PGETPHYSADDR)esas2r_disc_get_phys_addr;
  	sgc.length = offsetof(struct atto_ioctl, data)
  		     + sizeof(struct atto_hba_get_device_address);
  
  	esas2r_sgc_init(&sgc, a, rq, rq->vrq->ioctl.sge);
  
  	esas2r_build_ioctl_req(a, rq, sgc.length, VDA_IOCTL_HBA);
  
  	if (!esas2r_build_sg_list(a, rq, &sgc)) {
  		esas2r_rq_destroy_request(rq, a);
  
  		esas2r_trace_exit();
  
  		return false;
  	}
  
  	rq->comp_cb = esas2r_disc_passthru_dev_addr_cb;
  
  	rq->interrupt_cx = dc;
  
  	/* format the IOCTL data. */
  
  	hi = (struct atto_ioctl *)a->disc_buffer;
  
  	memset(a->disc_buffer, 0, ESAS2R_DISC_BUF_LEN);
  
  	hi->version = ATTO_VER_GET_DEV_ADDR0;
  	hi->function = ATTO_FUNC_GET_DEV_ADDR;
  	hi->flags = HBAF_TUNNEL;
  
  	hi->data.get_dev_addr.target_id = le32_to_cpu(dc->curr_phys_id);
  	hi->data.get_dev_addr.addr_type = dc->dev_addr_type;
  
  	/* start it up. */
  
  	rslt = esas2r_disc_start_request(a, rq);
  
  	esas2r_trace_exit();
  
  	return rslt;
  }
  
  static void esas2r_disc_passthru_dev_addr_cb(struct esas2r_adapter *a,
  					     struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	struct esas2r_target *t = NULL;
  	unsigned long flags;
  	struct atto_ioctl *hi;
  	u16 addrlen;
  
  	esas2r_trace_enter();
  
  	spin_lock_irqsave(&a->mem_lock, flags);
  
  	hi = (struct atto_ioctl *)a->disc_buffer;
  
  	if (rq->req_stat == RS_SUCCESS
  	    && hi->status == ATTO_STS_SUCCESS) {
  		addrlen = le16_to_cpu(hi->data.get_dev_addr.addr_len);
  
  		if (dc->dev_addr_type == ATTO_GDA_AT_PORT) {
  			if (addrlen == sizeof(u64))
  				memcpy(&dc->sas_addr,
  				       &hi->data.get_dev_addr.address[0],
  				       addrlen);
  			else
  				memset(&dc->sas_addr, 0, sizeof(dc->sas_addr));
  
  			/* Get the unique identifier. */
  			dc->dev_addr_type = ATTO_GDA_AT_UNIQUE;
  
  			goto next_dev_addr;
  		} else {
  			/* Add the pass through target. */
  			if (HIBYTE(addrlen) == 0) {
  				t = esas2r_targ_db_add_pthru(a,
  							     dc,
  							     &hi->data.
  							     get_dev_addr.
  							     address[0],
  							     (u8)hi->data.
  							     get_dev_addr.
  							     addr_len);
  
  				if (t)
  					memcpy(&t->sas_addr, &dc->sas_addr,
  					       sizeof(t->sas_addr));
  			} else {
  				/* getting the back end data failed */
  
  				esas2r_log(ESAS2R_LOG_WARN,
  					   "an error occurred retrieving the "
  					   "back end data (%s:%d)",
  					   __func__,
  					   __LINE__);
  			}
  		}
  	} else {
  		/* getting the back end data failed */
  
  		esas2r_log(ESAS2R_LOG_WARN,
  			   "an error occurred retrieving the back end data - "
  			   "rq->req_stat:%d hi->status:%d",
  			   rq->req_stat, hi->status);
  	}
  
  	/* proceed to the next device. */
  
  	if (dc->flags & DCF_DEV_SCAN) {
  		dc->dev_ix++;
  		dc->state = DCS_PT_DEV_INFO;
  	} else if (dc->flags & DCF_DEV_CHANGE) {
  		dc->curr_targ++;
  		dc->state = DCS_DEV_ADD;
  	} else {
  		esas2r_bugon();
  	}
  
  next_dev_addr:
  	esas2r_rq_destroy_request(rq, a);
  
  	/* continue discovery if it's interrupt driven */
  
  	if (!(dc->flags & DCF_POLLED))
  		esas2r_disc_continue(a, rq);
  
  	spin_unlock_irqrestore(&a->mem_lock, flags);
  
  	esas2r_trace_exit();
  }
  
  static u32 esas2r_disc_get_phys_addr(struct esas2r_sg_context *sgc, u64 *addr)
  {
  	struct esas2r_adapter *a = sgc->adapter;
  
  	if (sgc->length > ESAS2R_DISC_BUF_LEN)
  		esas2r_bugon();
  
  	*addr = a->uncached_phys
  		+ (u64)((u8 *)a->disc_buffer - a->uncached);
  
  	return sgc->length;
  }
  
  static bool esas2r_disc_dev_remove(struct esas2r_adapter *a,
  				   struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	struct esas2r_target *t;
  	struct esas2r_target *t2;
  
  	esas2r_trace_enter();
  
  	/* process removals. */
  
  	for (t = a->targetdb; t < a->targetdb_end; t++) {
  		if (t->new_target_state != TS_NOT_PRESENT)
  			continue;
  
  		t->new_target_state = TS_INVALID;
  
  		/* remove the right target! */
  
  		t2 =
  			esas2r_targ_db_find_by_virt_id(a,
  						       esas2r_targ_get_id(t,
  									  a));
  
  		if (t2)
  			esas2r_targ_db_remove(a, t2);
  	}
  
  	/* removals complete.  process arrivals. */
  
  	dc->state = DCS_DEV_ADD;
  	dc->curr_targ = a->targetdb;
  
  	esas2r_trace_exit();
  
  	return false;
  }
  
  static bool esas2r_disc_dev_add(struct esas2r_adapter *a,
  				struct esas2r_request *rq)
  {
  	struct esas2r_disc_context *dc =
  		(struct esas2r_disc_context *)rq->interrupt_cx;
  	struct esas2r_target *t = dc->curr_targ;
  
  	if (t >= a->targetdb_end) {
  		/* done processing state changes. */
  
  		dc->state = DCS_DISC_DONE;
  	} else if (t->new_target_state == TS_PRESENT) {
  		struct atto_vda_ae_lu *luevt = &t->lu_event;
  
  		esas2r_trace_enter();
  
  		/* clear this now in case more events come in. */
  
  		t->new_target_state = TS_INVALID;
  
  		/* setup the discovery context for adding this device. */
  
  		dc->curr_virt_id = esas2r_targ_get_id(t, a);
  
  		if ((luevt->hdr.bylength >= offsetof(struct atto_vda_ae_lu, id)
  		     + sizeof(struct atto_vda_ae_lu_tgt_lun_raid))
  		    && !(luevt->dwevent & VDAAE_LU_PASSTHROUGH)) {
  			dc->block_size = luevt->id.tgtlun_raid.dwblock_size;
  			dc->interleave = luevt->id.tgtlun_raid.dwinterleave;
  		} else {
  			dc->block_size = 0;
  			dc->interleave = 0;
  		}
  
  		/* determine the device type being added. */
  
  		if (luevt->dwevent & VDAAE_LU_PASSTHROUGH) {
  			if (luevt->dwevent & VDAAE_LU_PHYS_ID) {
  				dc->state = DCS_PT_DEV_ADDR;
  				dc->dev_addr_type = ATTO_GDA_AT_PORT;
  				dc->curr_phys_id = luevt->wphys_target_id;
  			} else {
  				esas2r_log(ESAS2R_LOG_WARN,
  					   "luevt->dwevent does not have the "
  					   "VDAAE_LU_PHYS_ID bit set (%s:%d)",
  					   __func__, __LINE__);
  			}
  		} else {
  			dc->raid_grp_name[0] = 0;
  
  			esas2r_targ_db_add_raid(a, dc);
  		}
  
  		esas2r_trace("curr_virt_id: %d", dc->curr_virt_id);
  		esas2r_trace("curr_phys_id: %d", dc->curr_phys_id);
  		esas2r_trace("dwevent: %d", luevt->dwevent);
  
  		esas2r_trace_exit();
  	}
  
  	if (dc->state == DCS_DEV_ADD) {
  		/* go to the next device. */
  
  		dc->curr_targ++;
  	}
  
  	return false;
  }
  
  /*
   * When discovery is done, find all requests on defer queue and
   * test if they need to be modified. If a target is no longer present
   * then complete the request with RS_SEL. Otherwise, update the
   * target_id since after a hibernate it can be a different value.
   * VDA does not make passthrough target IDs persistent.
   */
  static void esas2r_disc_fix_curr_requests(struct esas2r_adapter *a)
  {
  	unsigned long flags;
  	struct esas2r_target *t;
  	struct esas2r_request *rq;
  	struct list_head *element;
  
  	/* update virt_targ_id in any outstanding esas2r_requests  */
  
  	spin_lock_irqsave(&a->queue_lock, flags);
  
  	list_for_each(element, &a->defer_list) {
  		rq = list_entry(element, struct esas2r_request, req_list);
  		if (rq->vrq->scsi.function == VDA_FUNC_SCSI) {
  			t = a->targetdb + rq->target_id;
  
  			if (t->target_state == TS_PRESENT)
  				rq->vrq->scsi.target_id = le16_to_cpu(
  					t->virt_targ_id);
  			else
  				rq->req_stat = RS_SEL;
  		}
  
  	}
  
  	spin_unlock_irqrestore(&a->queue_lock, flags);
  }
  