drivers/scsi/libsas/sas_ata.c - LeafOS-Devices/android_kernel_realme_mt6785 - Gitiles

 /*
  * Support for SATA devices on Serial Attached SCSI (SAS) controllers
  *
  * Copyright (C) 2006 IBM Corporation
  *
  * Written by: Darrick J. Wong <djwong@us.ibm.com>, IBM Corporation
  *
  * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  * USA
  */

 #include <linux/scatterlist.h>

 #include <scsi/sas_ata.h>
 #include "sas_internal.h"
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_tcq.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_transport.h>
 #include <scsi/scsi_transport_sas.h>
 #include "../scsi_sas_internal.h"
 #include "../scsi_transport_api.h"
 #include <scsi/scsi_eh.h>

 static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
 {
 	/* Cheesy attempt to translate SAS errors into ATA.  Hah! */

 	/* transport error */
 	if (ts->resp == SAS_TASK_UNDELIVERED)
 		return AC_ERR_ATA_BUS;

 	/* ts->resp == SAS_TASK_COMPLETE */
 	/* task delivered, what happened afterwards? */
 	switch (ts->stat) {
 		case SAS_DEV_NO_RESPONSE:
 			return AC_ERR_TIMEOUT;

 		case SAS_INTERRUPTED:
 		case SAS_PHY_DOWN:
 		case SAS_NAK_R_ERR:
 			return AC_ERR_ATA_BUS;


 		case SAS_DATA_UNDERRUN:
 			/*
 			 * Some programs that use the taskfile interface
 			 * (smartctl in particular) can cause underrun
 			 * problems.  Ignore these errors, perhaps at our
 			 * peril.
 			 */
 			return 0;

 		case SAS_DATA_OVERRUN:
 		case SAS_QUEUE_FULL:
 		case SAS_DEVICE_UNKNOWN:
 		case SAS_SG_ERR:
 			return AC_ERR_INVALID;

 		case SAM_CHECK_COND:
 		case SAS_OPEN_TO:
 		case SAS_OPEN_REJECT:
 			SAS_DPRINTK("%s: Saw error %d.  What to do?\n",
 				    __func__, ts->stat);
 			return AC_ERR_OTHER;

 		case SAS_ABORTED_TASK:
 			return AC_ERR_DEV;

 		case SAS_PROTO_RESPONSE:
 			/* This means the ending_fis has the error
 			 * value; return 0 here to collect it */
 			return 0;
 		default:
 			return 0;
 	}
 }

 static void sas_ata_task_done(struct sas_task *task)
 {
 	struct ata_queued_cmd *qc = task->uldd_task;
 	struct domain_device *dev;
 	struct task_status_struct *stat = &task->task_status;
 	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
 	struct sas_ha_struct *sas_ha;
 	enum ata_completion_errors ac;
 	unsigned long flags;

 	if (!qc)
 		goto qc_already_gone;

 	dev = qc->ap->private_data;
 	sas_ha = dev->port->ha;

 	spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
 	if (stat->stat == SAS_PROTO_RESPONSE || stat->stat == SAM_GOOD) {
 		ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);
 		qc->err_mask |= ac_err_mask(dev->sata_dev.tf.command);
 		dev->sata_dev.sstatus = resp->sstatus;
 		dev->sata_dev.serror = resp->serror;
 		dev->sata_dev.scontrol = resp->scontrol;
 	} else if (stat->stat != SAM_STAT_GOOD) {
 		ac = sas_to_ata_err(stat);
 		if (ac) {
 			SAS_DPRINTK("%s: SAS error %x\n", __func__,
 				    stat->stat);
 			/* We saw a SAS error. Send a vague error. */
 			qc->err_mask = ac;
 			dev->sata_dev.tf.feature = 0x04; /* status err */
 			dev->sata_dev.tf.command = ATA_ERR;
 		}
 	}

 	qc->lldd_task = NULL;
 	if (qc->scsicmd)
 		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
 	ata_qc_complete(qc);
 	spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);

 	/*
 	 * If the sas_task has an ata qc, a scsi_cmnd and the aborted
 	 * flag is set, then we must have come in via the libsas EH
 	 * functions.  When we exit this function, we need to put the
 	 * scsi_cmnd on the list of finished errors.  The ata_qc_complete
 	 * call cleans up the libata side of things but we're protected
 	 * from the scsi_cmnd going away because the scsi_cmnd is owned
 	 * by the EH, making libata's call to scsi_done a NOP.
 	 */
 	spin_lock_irqsave(&task->task_state_lock, flags);
 	if (qc->scsicmd && task->task_state_flags & SAS_TASK_STATE_ABORTED)
 		scsi_eh_finish_cmd(qc->scsicmd, &sas_ha->eh_done_q);
 	spin_unlock_irqrestore(&task->task_state_lock, flags);

 qc_already_gone:
 	list_del_init(&task->list);
 	sas_free_task(task);
 }

 static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
 {
 	int res;
 	struct sas_task *task;
 	struct domain_device *dev = qc->ap->private_data;
 	struct sas_ha_struct *sas_ha = dev->port->ha;
 	struct Scsi_Host *host = sas_ha->core.shost;
 	struct sas_internal *i = to_sas_internal(host->transportt);
 	struct scatterlist *sg;
 	unsigned int xfer = 0;
 	unsigned int si;

 	task = sas_alloc_task(GFP_ATOMIC);
 	if (!task)
 		return AC_ERR_SYSTEM;
 	task->dev = dev;
 	task->task_proto = SAS_PROTOCOL_STP;
 	task->task_done = sas_ata_task_done;

 	if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
 	    qc->tf.command == ATA_CMD_FPDMA_READ) {
 		/* Need to zero out the tag libata assigned us */
 		qc->tf.nsect = 0;
 	}

 	ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
 	task->uldd_task = qc;
 	if (ata_is_atapi(qc->tf.protocol)) {
 		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
 		task->total_xfer_len = qc->nbytes;
 		task->num_scatter = qc->n_elem;
 	} else {
 		for_each_sg(qc->sg, sg, qc->n_elem, si)
 			xfer += sg->length;

 		task->total_xfer_len = xfer;
 		task->num_scatter = si;
 	}

 	task->data_dir = qc->dma_dir;
 	task->scatter = qc->sg;
 	task->ata_task.retry_count = 1;
 	task->task_state_flags = SAS_TASK_STATE_PENDING;
 	qc->lldd_task = task;

 	switch (qc->tf.protocol) {
 	case ATA_PROT_NCQ:
 		task->ata_task.use_ncq = 1;
 		/* fall through */
 	case ATAPI_PROT_DMA:
 	case ATA_PROT_DMA:
 		task->ata_task.dma_xfer = 1;
 		break;
 	}

 	if (qc->scsicmd)
 		ASSIGN_SAS_TASK(qc->scsicmd, task);

 	if (sas_ha->lldd_max_execute_num < 2)
 		res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
 	else
 		res = sas_queue_up(task);

 	/* Examine */
 	if (res) {
 		SAS_DPRINTK("lldd_execute_task returned: %d\n", res);

 		if (qc->scsicmd)
 			ASSIGN_SAS_TASK(qc->scsicmd, NULL);
 		sas_free_task(task);
 		return AC_ERR_SYSTEM;
 	}

 	return 0;
 }

 static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
 {
 	struct domain_device *dev = qc->ap->private_data;

 	memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
 	return true;
 }

 static void sas_ata_phy_reset(struct ata_port *ap)
 {
 	struct domain_device *dev = ap->private_data;
 	struct sas_internal *i =
 		to_sas_internal(dev->port->ha->core.shost->transportt);
 	int res = TMF_RESP_FUNC_FAILED;

 	if (i->dft->lldd_I_T_nexus_reset)
 		res = i->dft->lldd_I_T_nexus_reset(dev);

 	if (res != TMF_RESP_FUNC_COMPLETE)
 		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);

 	switch (dev->sata_dev.command_set) {
 		case ATA_COMMAND_SET:
 			SAS_DPRINTK("%s: Found ATA device.\n", __func__);
 			ap->link.device[0].class = ATA_DEV_ATA;
 			break;
 		case ATAPI_COMMAND_SET:
 			SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
 			ap->link.device[0].class = ATA_DEV_ATAPI;
 			break;
 		default:
 			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
 				    __func__,
 				    dev->sata_dev.command_set);
 			ap->link.device[0].class = ATA_DEV_UNKNOWN;
 			break;
 	}

 	ap->cbl = ATA_CBL_SATA;
 }

 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
 {
 	if (qc->flags & ATA_QCFLAG_FAILED)
 		qc->err_mask |= AC_ERR_OTHER;

 	if (qc->err_mask) {
 		/*
 		 * Find the sas_task and kill it.  By this point,
 		 * libata has decided to kill the qc, so we needn't
 		 * bother with sas_ata_task_done.  But we still
 		 * ought to abort the task.
 		 */
 		struct sas_task *task = qc->lldd_task;
 		unsigned long flags;

 		qc->lldd_task = NULL;
 		if (task) {
 			/* Should this be a AT(API) device reset? */
 			spin_lock_irqsave(&task->task_state_lock, flags);
 			task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
 			spin_unlock_irqrestore(&task->task_state_lock, flags);

 			task->uldd_task = NULL;
 			__sas_task_abort(task);
 		}
 	}
 }

 static int sas_ata_scr_write(struct ata_link *link, unsigned int sc_reg_in,
 			      u32 val)
 {
 	struct domain_device *dev = link->ap->private_data;

 	SAS_DPRINTK("STUB %s\n", __func__);
 	switch (sc_reg_in) {
 		case SCR_STATUS:
 			dev->sata_dev.sstatus = val;
 			break;
 		case SCR_CONTROL:
 			dev->sata_dev.scontrol = val;
 			break;
 		case SCR_ERROR:
 			dev->sata_dev.serror = val;
 			break;
 		case SCR_ACTIVE:
 			dev->sata_dev.ap->link.sactive = val;
 			break;
 		default:
 			return -EINVAL;
 	}
 	return 0;
 }

 static int sas_ata_scr_read(struct ata_link *link, unsigned int sc_reg_in,
 			    u32 *val)
 {
 	struct domain_device *dev = link->ap->private_data;

 	SAS_DPRINTK("STUB %s\n", __func__);
 	switch (sc_reg_in) {
 		case SCR_STATUS:
 			*val = dev->sata_dev.sstatus;
 			return 0;
 		case SCR_CONTROL:
 			*val = dev->sata_dev.scontrol;
 			return 0;
 		case SCR_ERROR:
 			*val = dev->sata_dev.serror;
 			return 0;
 		case SCR_ACTIVE:
 			*val = dev->sata_dev.ap->link.sactive;
 			return 0;
 		default:
 			return -EINVAL;
 	}
 }

 static struct ata_port_operations sas_sata_ops = {
 	.phy_reset		= sas_ata_phy_reset,
 	.post_internal_cmd	= sas_ata_post_internal,
 	.qc_prep		= ata_noop_qc_prep,
 	.qc_issue		= sas_ata_qc_issue,
 	.qc_fill_rtf		= sas_ata_qc_fill_rtf,
 	.port_start		= ata_sas_port_start,
 	.port_stop		= ata_sas_port_stop,
 	.scr_read		= sas_ata_scr_read,
 	.scr_write		= sas_ata_scr_write
 };

 static struct ata_port_info sata_port_info = {
 	.flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY | ATA_FLAG_SATA_RESET |
 		ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
 	.pio_mask = 0x1f, /* PIO0-4 */
 	.mwdma_mask = 0x07, /* MWDMA0-2 */
 	.udma_mask = ATA_UDMA6,
 	.port_ops = &sas_sata_ops
 };

 int sas_ata_init_host_and_port(struct domain_device *found_dev,
 			       struct scsi_target *starget)
 {
 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
 	struct ata_port *ap;

 	ata_host_init(&found_dev->sata_dev.ata_host,
 		      ha->dev,
 		      sata_port_info.flags,
 		      &sas_sata_ops);
 	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
 				&sata_port_info,
 				shost);
 	if (!ap) {
 		SAS_DPRINTK("ata_sas_port_alloc failed.\n");
 		return -ENODEV;
 	}

 	ap->private_data = found_dev;
 	ap->cbl = ATA_CBL_SATA;
 	ap->scsi_host = shost;
 	found_dev->sata_dev.ap = ap;

 	return 0;
 }

 void sas_ata_task_abort(struct sas_task *task)
 {
 	struct ata_queued_cmd *qc = task->uldd_task;
 	struct completion *waiting;

 	/* Bounce SCSI-initiated commands to the SCSI EH */
 	if (qc->scsicmd) {
 		scsi_req_abort_cmd(qc->scsicmd);
 		scsi_schedule_eh(qc->scsicmd->device->host);
 		return;
 	}

 	/* Internal command, fake a timeout and complete. */
 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
 	qc->flags |= ATA_QCFLAG_FAILED;
 	qc->err_mask |= AC_ERR_TIMEOUT;
 	waiting = qc->private_data;
 	complete(waiting);
 }

 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
  * @dma_dir: DMA direction.  DMA_xxx
  */
 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
 			    enum dma_data_direction 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 (dma_dir != 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 = dma_dir;
 	task->task_done = sas_disc_task_done;
 	if (dma_dir != DMA_NONE &&
 	    sas_protocol_ata(task->task_proto)) {
 		task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
 					       task->scatter,
 					       task->num_scatter,
 					       task->data_dir);
 	}

 	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 = -ECOMM;
 		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 (dma_dir != DMA_NONE) {
 		if (sas_protocol_ata(task->task_proto))
 			dma_unmap_sg(task->dev->port->ha->dev,
 				     task->scatter, task->num_scatter,
 				     task->data_dir);
 		kfree(scatter);
 	}
 out:
 	return res;
 }

 /* ---------- 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
  * @dma_dir: DMA direction.  DMA_xxx
  */
 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
 			     u8 features, void *buffer, int size,
 			     enum dma_data_direction 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.fis_type = 0x27;
 	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, dma_dir);

 	sas_free_task(task);
 out:
 	return res;
 }

 #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,
 				DMA_FROM_DEVICE);
 	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 (!(identify_x[83] & cpu_to_le16(1<<6)))
 			goto cont1;
 		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
 					ATA_FEATURE_PUP_STBY_SPIN_UP,
 					NULL, 0, DMA_NONE);
 		if (res)
 			goto cont1;

 		schedule_timeout_interruptible(5*HZ); /* More time? */
 		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
 					DMA_FROM_DEVICE);
 		if (res)
 			goto out_err;
 	}
 cont1:
 	/* XXX Hint: register this SATA device with SATL.
 	   When this returns, dev->sata_dev->lu is alive and
 	   present.
 	sas_satl_register_dev(dev);
 	*/

 	sas_fill_in_rphy(dev, dev->rphy);

 	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;
 }

 /**
  * 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);
 		res = sas_rphy_add(dev->rphy);
 	}

 	return res;
 }
	/*
	* Support for SATA devices on Serial Attached SCSI (SAS) controllers
	*
	* Copyright (C) 2006 IBM Corporation
	*
	* Written by: Darrick J. Wong <djwong@us.ibm.com>, IBM Corporation
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
	* USA
	*/

	#include <linux/scatterlist.h>

	#include <scsi/sas_ata.h>
	#include "sas_internal.h"
	#include <scsi/scsi_host.h>
	#include <scsi/scsi_device.h>
	#include <scsi/scsi_tcq.h>
	#include <scsi/scsi.h>
	#include <scsi/scsi_transport.h>
	#include <scsi/scsi_transport_sas.h>
	#include "../scsi_sas_internal.h"
	#include "../scsi_transport_api.h"
	#include <scsi/scsi_eh.h>

	static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
	{
	/* Cheesy attempt to translate SAS errors into ATA. Hah! */

	/* transport error */
	if (ts->resp == SAS_TASK_UNDELIVERED)
	return AC_ERR_ATA_BUS;

	/* ts->resp == SAS_TASK_COMPLETE */
	/* task delivered, what happened afterwards? */
	switch (ts->stat) {
	case SAS_DEV_NO_RESPONSE:
	return AC_ERR_TIMEOUT;

	case SAS_INTERRUPTED:
	case SAS_PHY_DOWN:
	case SAS_NAK_R_ERR:
	return AC_ERR_ATA_BUS;


	case SAS_DATA_UNDERRUN:
	/*
	* Some programs that use the taskfile interface
	* (smartctl in particular) can cause underrun
	* problems. Ignore these errors, perhaps at our
	* peril.
	*/
	return 0;

	case SAS_DATA_OVERRUN:
	case SAS_QUEUE_FULL:
	case SAS_DEVICE_UNKNOWN:
	case SAS_SG_ERR:
	return AC_ERR_INVALID;

	case SAM_CHECK_COND:
	case SAS_OPEN_TO:
	case SAS_OPEN_REJECT:
	SAS_DPRINTK("%s: Saw error %d. What to do?\n",
	__func__, ts->stat);
	return AC_ERR_OTHER;

	case SAS_ABORTED_TASK:
	return AC_ERR_DEV;

	case SAS_PROTO_RESPONSE:
	/* This means the ending_fis has the error
	* value; return 0 here to collect it */
	return 0;
	default:
	return 0;
	}
	}

	static void sas_ata_task_done(struct sas_task *task)
	{
	struct ata_queued_cmd *qc = task->uldd_task;
	struct domain_device *dev;
	struct task_status_struct *stat = &task->task_status;
	struct ata_task_resp resp = (struct ata_task_resp )stat->buf;
	struct sas_ha_struct *sas_ha;
	enum ata_completion_errors ac;
	unsigned long flags;

	if (!qc)
	goto qc_already_gone;

	dev = qc->ap->private_data;
	sas_ha = dev->port->ha;

	spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
	if (stat->stat == SAS_PROTO_RESPONSE \|\| stat->stat == SAM_GOOD) {
	ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);
	qc->err_mask \|= ac_err_mask(dev->sata_dev.tf.command);
	dev->sata_dev.sstatus = resp->sstatus;
	dev->sata_dev.serror = resp->serror;
	dev->sata_dev.scontrol = resp->scontrol;
	} else if (stat->stat != SAM_STAT_GOOD) {
	ac = sas_to_ata_err(stat);
	if (ac) {
	SAS_DPRINTK("%s: SAS error %x\n", __func__,
	stat->stat);
	/* We saw a SAS error. Send a vague error. */
	qc->err_mask = ac;
	dev->sata_dev.tf.feature = 0x04; /* status err */
	dev->sata_dev.tf.command = ATA_ERR;
	}
	}

	qc->lldd_task = NULL;
	if (qc->scsicmd)
	ASSIGN_SAS_TASK(qc->scsicmd, NULL);
	ata_qc_complete(qc);
	spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);

	/*
	* If the sas_task has an ata qc, a scsi_cmnd and the aborted
	* flag is set, then we must have come in via the libsas EH
	* functions. When we exit this function, we need to put the
	* scsi_cmnd on the list of finished errors. The ata_qc_complete
	* call cleans up the libata side of things but we're protected
	* from the scsi_cmnd going away because the scsi_cmnd is owned
	* by the EH, making libata's call to scsi_done a NOP.
	*/
	spin_lock_irqsave(&task->task_state_lock, flags);
	if (qc->scsicmd && task->task_state_flags & SAS_TASK_STATE_ABORTED)
	scsi_eh_finish_cmd(qc->scsicmd, &sas_ha->eh_done_q);
	spin_unlock_irqrestore(&task->task_state_lock, flags);

	qc_already_gone:
	list_del_init(&task->list);
	sas_free_task(task);
	}

	static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
	{
	int res;
	struct sas_task *task;
	struct domain_device *dev = qc->ap->private_data;
	struct sas_ha_struct *sas_ha = dev->port->ha;
	struct Scsi_Host *host = sas_ha->core.shost;
	struct sas_internal *i = to_sas_internal(host->transportt);
	struct scatterlist *sg;
	unsigned int xfer = 0;
	unsigned int si;

	task = sas_alloc_task(GFP_ATOMIC);
	if (!task)
	return AC_ERR_SYSTEM;
	task->dev = dev;
	task->task_proto = SAS_PROTOCOL_STP;
	task->task_done = sas_ata_task_done;

	if (qc->tf.command == ATA_CMD_FPDMA_WRITE \|\|
	qc->tf.command == ATA_CMD_FPDMA_READ) {
	/* Need to zero out the tag libata assigned us */
	qc->tf.nsect = 0;
	}

	ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
	task->uldd_task = qc;
	if (ata_is_atapi(qc->tf.protocol)) {
	memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
	task->total_xfer_len = qc->nbytes;
	task->num_scatter = qc->n_elem;
	} else {
	for_each_sg(qc->sg, sg, qc->n_elem, si)
	xfer += sg->length;

	task->total_xfer_len = xfer;
	task->num_scatter = si;
	}

	task->data_dir = qc->dma_dir;
	task->scatter = qc->sg;
	task->ata_task.retry_count = 1;
	task->task_state_flags = SAS_TASK_STATE_PENDING;
	qc->lldd_task = task;

	switch (qc->tf.protocol) {
	case ATA_PROT_NCQ:
	task->ata_task.use_ncq = 1;
	/* fall through */
	case ATAPI_PROT_DMA:
	case ATA_PROT_DMA:
	task->ata_task.dma_xfer = 1;
	break;
	}

	if (qc->scsicmd)
	ASSIGN_SAS_TASK(qc->scsicmd, task);

	if (sas_ha->lldd_max_execute_num < 2)
	res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
	else
	res = sas_queue_up(task);

	/* Examine */
	if (res) {
	SAS_DPRINTK("lldd_execute_task returned: %d\n", res);

	if (qc->scsicmd)
	ASSIGN_SAS_TASK(qc->scsicmd, NULL);
	sas_free_task(task);
	return AC_ERR_SYSTEM;
	}

	return 0;
	}

	static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
	{
	struct domain_device *dev = qc->ap->private_data;

	memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
	return true;
	}

	static void sas_ata_phy_reset(struct ata_port *ap)
	{
	struct domain_device *dev = ap->private_data;
	struct sas_internal *i =
	to_sas_internal(dev->port->ha->core.shost->transportt);
	int res = TMF_RESP_FUNC_FAILED;

	if (i->dft->lldd_I_T_nexus_reset)
	res = i->dft->lldd_I_T_nexus_reset(dev);

	if (res != TMF_RESP_FUNC_COMPLETE)
	SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);

	switch (dev->sata_dev.command_set) {
	case ATA_COMMAND_SET:
	SAS_DPRINTK("%s: Found ATA device.\n", __func__);
	ap->link.device[0].class = ATA_DEV_ATA;
	break;
	case ATAPI_COMMAND_SET:
	SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
	ap->link.device[0].class = ATA_DEV_ATAPI;
	break;
	default:
	SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
	__func__,
	dev->sata_dev.command_set);
	ap->link.device[0].class = ATA_DEV_UNKNOWN;
	break;
	}

	ap->cbl = ATA_CBL_SATA;
	}

	static void sas_ata_post_internal(struct ata_queued_cmd *qc)
	{
	if (qc->flags & ATA_QCFLAG_FAILED)
	qc->err_mask \|= AC_ERR_OTHER;

	if (qc->err_mask) {
	/*
	* Find the sas_task and kill it. By this point,
	* libata has decided to kill the qc, so we needn't
	* bother with sas_ata_task_done. But we still
	* ought to abort the task.
	*/
	struct sas_task *task = qc->lldd_task;
	unsigned long flags;

	qc->lldd_task = NULL;
	if (task) {
	/* Should this be a AT(API) device reset? */
	spin_lock_irqsave(&task->task_state_lock, flags);
	task->task_state_flags \|= SAS_TASK_NEED_DEV_RESET;
	spin_unlock_irqrestore(&task->task_state_lock, flags);

	task->uldd_task = NULL;
	__sas_task_abort(task);
	}
	}
	}

	static int sas_ata_scr_write(struct ata_link *link, unsigned int sc_reg_in,
	u32 val)
	{
	struct domain_device *dev = link->ap->private_data;

	SAS_DPRINTK("STUB %s\n", __func__);
	switch (sc_reg_in) {
	case SCR_STATUS:
	dev->sata_dev.sstatus = val;
	break;
	case SCR_CONTROL:
	dev->sata_dev.scontrol = val;
	break;
	case SCR_ERROR:
	dev->sata_dev.serror = val;
	break;
	case SCR_ACTIVE:
	dev->sata_dev.ap->link.sactive = val;
	break;
	default:
	return -EINVAL;
	}
	return 0;
	}

	static int sas_ata_scr_read(struct ata_link *link, unsigned int sc_reg_in,
	u32 *val)
	{
	struct domain_device *dev = link->ap->private_data;

	SAS_DPRINTK("STUB %s\n", __func__);
	switch (sc_reg_in) {
	case SCR_STATUS:
	*val = dev->sata_dev.sstatus;
	return 0;
	case SCR_CONTROL:
	*val = dev->sata_dev.scontrol;
	return 0;
	case SCR_ERROR:
	*val = dev->sata_dev.serror;
	return 0;
	case SCR_ACTIVE:
	*val = dev->sata_dev.ap->link.sactive;
	return 0;
	default:
	return -EINVAL;
	}
	}

	static struct ata_port_operations sas_sata_ops = {
	.phy_reset = sas_ata_phy_reset,
	.post_internal_cmd = sas_ata_post_internal,
	.qc_prep = ata_noop_qc_prep,
	.qc_issue = sas_ata_qc_issue,
	.qc_fill_rtf = sas_ata_qc_fill_rtf,
	.port_start = ata_sas_port_start,
	.port_stop = ata_sas_port_stop,
	.scr_read = sas_ata_scr_read,
	.scr_write = sas_ata_scr_write
	};

	static struct ata_port_info sata_port_info = {
	.flags = ATA_FLAG_SATA \| ATA_FLAG_NO_LEGACY \| ATA_FLAG_SATA_RESET \|
	ATA_FLAG_MMIO \| ATA_FLAG_PIO_DMA \| ATA_FLAG_NCQ,
	.pio_mask = 0x1f, /* PIO0-4 */
	.mwdma_mask = 0x07, /* MWDMA0-2 */
	.udma_mask = ATA_UDMA6,
	.port_ops = &sas_sata_ops
	};

	int sas_ata_init_host_and_port(struct domain_device *found_dev,
	struct scsi_target *starget)
	{
	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
	struct ata_port *ap;

	ata_host_init(&found_dev->sata_dev.ata_host,
	ha->dev,
	sata_port_info.flags,
	&sas_sata_ops);
	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
	&sata_port_info,
	shost);
	if (!ap) {
	SAS_DPRINTK("ata_sas_port_alloc failed.\n");
	return -ENODEV;
	}

	ap->private_data = found_dev;
	ap->cbl = ATA_CBL_SATA;
	ap->scsi_host = shost;
	found_dev->sata_dev.ap = ap;

	return 0;
	}

	void sas_ata_task_abort(struct sas_task *task)
	{
	struct ata_queued_cmd *qc = task->uldd_task;
	struct completion *waiting;

	/* Bounce SCSI-initiated commands to the SCSI EH */
	if (qc->scsicmd) {
	scsi_req_abort_cmd(qc->scsicmd);
	scsi_schedule_eh(qc->scsicmd->device->host);
	return;
	}

	/* Internal command, fake a timeout and complete. */
	qc->flags &= ~ATA_QCFLAG_ACTIVE;
	qc->flags \|= ATA_QCFLAG_FAILED;
	qc->err_mask \|= AC_ERR_TIMEOUT;
	waiting = qc->private_data;
	complete(waiting);
	}

	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
	* @dma_dir: DMA direction. DMA_xxx
	*/
	static int sas_execute_task(struct sas_task task, void buffer, int size,
	enum dma_data_direction 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 (dma_dir != 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 = dma_dir;
	task->task_done = sas_disc_task_done;
	if (dma_dir != DMA_NONE &&
	sas_protocol_ata(task->task_proto)) {
	task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
	task->scatter,
	task->num_scatter,
	task->data_dir);
	}

	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 = -ECOMM;
	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 (dma_dir != DMA_NONE) {
	if (sas_protocol_ata(task->task_proto))
	dma_unmap_sg(task->dev->port->ha->dev,
	task->scatter, task->num_scatter,
	task->data_dir);
	kfree(scatter);
	}
	out:
	return res;
	}

	/* ---------- 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
	* @dma_dir: DMA direction. DMA_xxx
	*/
	static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
	u8 features, void *buffer, int size,
	enum dma_data_direction 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.fis_type = 0x27;
	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, dma_dir);

	sas_free_task(task);
	out:
	return res;
	}

	#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,
	DMA_FROM_DEVICE);
	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 (!(identify_x[83] & cpu_to_le16(1<<6)))
	goto cont1;
	res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
	ATA_FEATURE_PUP_STBY_SPIN_UP,
	NULL, 0, DMA_NONE);
	if (res)
	goto cont1;

	schedule_timeout_interruptible(5HZ); / More time? */
	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
	DMA_FROM_DEVICE);
	if (res)
	goto out_err;
	}
	cont1:
	/* XXX Hint: register this SATA device with SATL.
	When this returns, dev->sata_dev->lu is alive and
	present.
	sas_satl_register_dev(dev);
	*/

	sas_fill_in_rphy(dev, dev->rphy);

	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;
	}

	/**
	* 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);
	res = sas_rphy_add(dev->rphy);
	}

	return res;
	}