xref: /linux/drivers/scsi/libsas/sas_ata.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
1 /*
2  * Support for SATA devices on Serial Attached SCSI (SAS) controllers
3  *
4  * Copyright (C) 2006 IBM Corporation
5  *
6  * Written by: Darrick J. Wong <djwong@us.ibm.com>, IBM Corporation
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of the
11  * License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
21  * USA
22  */
23 
24 #include <linux/scatterlist.h>
25 
26 #include <scsi/sas_ata.h>
27 #include "sas_internal.h"
28 #include <scsi/scsi_host.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_tcq.h>
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_transport.h>
33 #include <scsi/scsi_transport_sas.h>
34 #include "../scsi_sas_internal.h"
35 #include "../scsi_transport_api.h"
36 #include <scsi/scsi_eh.h>
37 
38 static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
39 {
40 	/* Cheesy attempt to translate SAS errors into ATA.  Hah! */
41 
42 	/* transport error */
43 	if (ts->resp == SAS_TASK_UNDELIVERED)
44 		return AC_ERR_ATA_BUS;
45 
46 	/* ts->resp == SAS_TASK_COMPLETE */
47 	/* task delivered, what happened afterwards? */
48 	switch (ts->stat) {
49 		case SAS_DEV_NO_RESPONSE:
50 			return AC_ERR_TIMEOUT;
51 
52 		case SAS_INTERRUPTED:
53 		case SAS_PHY_DOWN:
54 		case SAS_NAK_R_ERR:
55 			return AC_ERR_ATA_BUS;
56 
57 
58 		case SAS_DATA_UNDERRUN:
59 			/*
60 			 * Some programs that use the taskfile interface
61 			 * (smartctl in particular) can cause underrun
62 			 * problems.  Ignore these errors, perhaps at our
63 			 * peril.
64 			 */
65 			return 0;
66 
67 		case SAS_DATA_OVERRUN:
68 		case SAS_QUEUE_FULL:
69 		case SAS_DEVICE_UNKNOWN:
70 		case SAS_SG_ERR:
71 			return AC_ERR_INVALID;
72 
73 		case SAM_CHECK_COND:
74 		case SAS_OPEN_TO:
75 		case SAS_OPEN_REJECT:
76 			SAS_DPRINTK("%s: Saw error %d.  What to do?\n",
77 				    __FUNCTION__, ts->stat);
78 			return AC_ERR_OTHER;
79 
80 		case SAS_ABORTED_TASK:
81 			return AC_ERR_DEV;
82 
83 		case SAS_PROTO_RESPONSE:
84 			/* This means the ending_fis has the error
85 			 * value; return 0 here to collect it */
86 			return 0;
87 		default:
88 			return 0;
89 	}
90 }
91 
92 static void sas_ata_task_done(struct sas_task *task)
93 {
94 	struct ata_queued_cmd *qc = task->uldd_task;
95 	struct domain_device *dev;
96 	struct task_status_struct *stat = &task->task_status;
97 	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
98 	struct sas_ha_struct *sas_ha;
99 	enum ata_completion_errors ac;
100 	unsigned long flags;
101 
102 	if (!qc)
103 		goto qc_already_gone;
104 
105 	dev = qc->ap->private_data;
106 	sas_ha = dev->port->ha;
107 
108 	spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
109 	if (stat->stat == SAS_PROTO_RESPONSE || stat->stat == SAM_GOOD) {
110 		ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);
111 		qc->err_mask |= ac_err_mask(dev->sata_dev.tf.command);
112 		dev->sata_dev.sstatus = resp->sstatus;
113 		dev->sata_dev.serror = resp->serror;
114 		dev->sata_dev.scontrol = resp->scontrol;
115 	} else if (stat->stat != SAM_STAT_GOOD) {
116 		ac = sas_to_ata_err(stat);
117 		if (ac) {
118 			SAS_DPRINTK("%s: SAS error %x\n", __FUNCTION__,
119 				    stat->stat);
120 			/* We saw a SAS error. Send a vague error. */
121 			qc->err_mask = ac;
122 			dev->sata_dev.tf.feature = 0x04; /* status err */
123 			dev->sata_dev.tf.command = ATA_ERR;
124 		}
125 	}
126 
127 	qc->lldd_task = NULL;
128 	if (qc->scsicmd)
129 		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
130 	ata_qc_complete(qc);
131 	spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
132 
133 	/*
134 	 * If the sas_task has an ata qc, a scsi_cmnd and the aborted
135 	 * flag is set, then we must have come in via the libsas EH
136 	 * functions.  When we exit this function, we need to put the
137 	 * scsi_cmnd on the list of finished errors.  The ata_qc_complete
138 	 * call cleans up the libata side of things but we're protected
139 	 * from the scsi_cmnd going away because the scsi_cmnd is owned
140 	 * by the EH, making libata's call to scsi_done a NOP.
141 	 */
142 	spin_lock_irqsave(&task->task_state_lock, flags);
143 	if (qc->scsicmd && task->task_state_flags & SAS_TASK_STATE_ABORTED)
144 		scsi_eh_finish_cmd(qc->scsicmd, &sas_ha->eh_done_q);
145 	spin_unlock_irqrestore(&task->task_state_lock, flags);
146 
147 qc_already_gone:
148 	list_del_init(&task->list);
149 	sas_free_task(task);
150 }
151 
152 static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
153 {
154 	int res;
155 	struct sas_task *task;
156 	struct domain_device *dev = qc->ap->private_data;
157 	struct sas_ha_struct *sas_ha = dev->port->ha;
158 	struct Scsi_Host *host = sas_ha->core.shost;
159 	struct sas_internal *i = to_sas_internal(host->transportt);
160 	struct scatterlist *sg;
161 	unsigned int num = 0;
162 	unsigned int xfer = 0;
163 
164 	task = sas_alloc_task(GFP_ATOMIC);
165 	if (!task)
166 		return AC_ERR_SYSTEM;
167 	task->dev = dev;
168 	task->task_proto = SAS_PROTOCOL_STP;
169 	task->task_done = sas_ata_task_done;
170 
171 	if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
172 	    qc->tf.command == ATA_CMD_FPDMA_READ) {
173 		/* Need to zero out the tag libata assigned us */
174 		qc->tf.nsect = 0;
175 	}
176 
177 	ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
178 	task->uldd_task = qc;
179 	if (is_atapi_taskfile(&qc->tf)) {
180 		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
181 		task->total_xfer_len = qc->nbytes + qc->pad_len;
182 		task->num_scatter = qc->pad_len ? qc->n_elem + 1 : qc->n_elem;
183 	} else {
184 		ata_for_each_sg(sg, qc) {
185 			num++;
186 			xfer += sg->length;
187 		}
188 
189 		task->total_xfer_len = xfer;
190 		task->num_scatter = num;
191 	}
192 
193 	task->data_dir = qc->dma_dir;
194 	task->scatter = qc->__sg;
195 	task->ata_task.retry_count = 1;
196 	task->task_state_flags = SAS_TASK_STATE_PENDING;
197 	qc->lldd_task = task;
198 
199 	switch (qc->tf.protocol) {
200 	case ATA_PROT_NCQ:
201 		task->ata_task.use_ncq = 1;
202 		/* fall through */
203 	case ATA_PROT_ATAPI_DMA:
204 	case ATA_PROT_DMA:
205 		task->ata_task.dma_xfer = 1;
206 		break;
207 	}
208 
209 	if (qc->scsicmd)
210 		ASSIGN_SAS_TASK(qc->scsicmd, task);
211 
212 	if (sas_ha->lldd_max_execute_num < 2)
213 		res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
214 	else
215 		res = sas_queue_up(task);
216 
217 	/* Examine */
218 	if (res) {
219 		SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
220 
221 		if (qc->scsicmd)
222 			ASSIGN_SAS_TASK(qc->scsicmd, NULL);
223 		sas_free_task(task);
224 		return AC_ERR_SYSTEM;
225 	}
226 
227 	return 0;
228 }
229 
230 static u8 sas_ata_check_status(struct ata_port *ap)
231 {
232 	struct domain_device *dev = ap->private_data;
233 	return dev->sata_dev.tf.command;
234 }
235 
236 static void sas_ata_phy_reset(struct ata_port *ap)
237 {
238 	struct domain_device *dev = ap->private_data;
239 	struct sas_internal *i =
240 		to_sas_internal(dev->port->ha->core.shost->transportt);
241 	int res = 0;
242 
243 	if (i->dft->lldd_I_T_nexus_reset)
244 		res = i->dft->lldd_I_T_nexus_reset(dev);
245 
246 	if (res)
247 		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __FUNCTION__);
248 
249 	switch (dev->sata_dev.command_set) {
250 		case ATA_COMMAND_SET:
251 			SAS_DPRINTK("%s: Found ATA device.\n", __FUNCTION__);
252 			ap->link.device[0].class = ATA_DEV_ATA;
253 			break;
254 		case ATAPI_COMMAND_SET:
255 			SAS_DPRINTK("%s: Found ATAPI device.\n", __FUNCTION__);
256 			ap->link.device[0].class = ATA_DEV_ATAPI;
257 			break;
258 		default:
259 			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
260 				    __FUNCTION__,
261 				    dev->sata_dev.command_set);
262 			ap->link.device[0].class = ATA_DEV_UNKNOWN;
263 			break;
264 	}
265 
266 	ap->cbl = ATA_CBL_SATA;
267 }
268 
269 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
270 {
271 	if (qc->flags & ATA_QCFLAG_FAILED)
272 		qc->err_mask |= AC_ERR_OTHER;
273 
274 	if (qc->err_mask) {
275 		/*
276 		 * Find the sas_task and kill it.  By this point,
277 		 * libata has decided to kill the qc, so we needn't
278 		 * bother with sas_ata_task_done.  But we still
279 		 * ought to abort the task.
280 		 */
281 		struct sas_task *task = qc->lldd_task;
282 		unsigned long flags;
283 
284 		qc->lldd_task = NULL;
285 		if (task) {
286 			/* Should this be a AT(API) device reset? */
287 			spin_lock_irqsave(&task->task_state_lock, flags);
288 			task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
289 			spin_unlock_irqrestore(&task->task_state_lock, flags);
290 
291 			task->uldd_task = NULL;
292 			__sas_task_abort(task);
293 		}
294 	}
295 }
296 
297 static void sas_ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
298 {
299 	struct domain_device *dev = ap->private_data;
300 	memcpy(tf, &dev->sata_dev.tf, sizeof (*tf));
301 }
302 
303 static int sas_ata_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
304 			      u32 val)
305 {
306 	struct domain_device *dev = ap->private_data;
307 
308 	SAS_DPRINTK("STUB %s\n", __FUNCTION__);
309 	switch (sc_reg_in) {
310 		case SCR_STATUS:
311 			dev->sata_dev.sstatus = val;
312 			break;
313 		case SCR_CONTROL:
314 			dev->sata_dev.scontrol = val;
315 			break;
316 		case SCR_ERROR:
317 			dev->sata_dev.serror = val;
318 			break;
319 		case SCR_ACTIVE:
320 			dev->sata_dev.ap->link.sactive = val;
321 			break;
322 		default:
323 			return -EINVAL;
324 	}
325 	return 0;
326 }
327 
328 static int sas_ata_scr_read(struct ata_port *ap, unsigned int sc_reg_in,
329 			    u32 *val)
330 {
331 	struct domain_device *dev = ap->private_data;
332 
333 	SAS_DPRINTK("STUB %s\n", __FUNCTION__);
334 	switch (sc_reg_in) {
335 		case SCR_STATUS:
336 			*val = dev->sata_dev.sstatus;
337 			return 0;
338 		case SCR_CONTROL:
339 			*val = dev->sata_dev.scontrol;
340 			return 0;
341 		case SCR_ERROR:
342 			*val = dev->sata_dev.serror;
343 			return 0;
344 		case SCR_ACTIVE:
345 			*val = dev->sata_dev.ap->link.sactive;
346 			return 0;
347 		default:
348 			return -EINVAL;
349 	}
350 }
351 
352 static struct ata_port_operations sas_sata_ops = {
353 	.check_status		= sas_ata_check_status,
354 	.check_altstatus	= sas_ata_check_status,
355 	.dev_select		= ata_noop_dev_select,
356 	.phy_reset		= sas_ata_phy_reset,
357 	.post_internal_cmd	= sas_ata_post_internal,
358 	.tf_read		= sas_ata_tf_read,
359 	.qc_prep		= ata_noop_qc_prep,
360 	.qc_issue		= sas_ata_qc_issue,
361 	.port_start		= ata_sas_port_start,
362 	.port_stop		= ata_sas_port_stop,
363 	.scr_read		= sas_ata_scr_read,
364 	.scr_write		= sas_ata_scr_write
365 };
366 
367 static struct ata_port_info sata_port_info = {
368 	.flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY | ATA_FLAG_SATA_RESET |
369 		ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
370 	.pio_mask = 0x1f, /* PIO0-4 */
371 	.mwdma_mask = 0x07, /* MWDMA0-2 */
372 	.udma_mask = ATA_UDMA6,
373 	.port_ops = &sas_sata_ops
374 };
375 
376 int sas_ata_init_host_and_port(struct domain_device *found_dev,
377 			       struct scsi_target *starget)
378 {
379 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
380 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
381 	struct ata_port *ap;
382 
383 	ata_host_init(&found_dev->sata_dev.ata_host,
384 		      ha->dev,
385 		      sata_port_info.flags,
386 		      &sas_sata_ops);
387 	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
388 				&sata_port_info,
389 				shost);
390 	if (!ap) {
391 		SAS_DPRINTK("ata_sas_port_alloc failed.\n");
392 		return -ENODEV;
393 	}
394 
395 	ap->private_data = found_dev;
396 	ap->cbl = ATA_CBL_SATA;
397 	ap->scsi_host = shost;
398 	found_dev->sata_dev.ap = ap;
399 
400 	return 0;
401 }
402 
403 void sas_ata_task_abort(struct sas_task *task)
404 {
405 	struct ata_queued_cmd *qc = task->uldd_task;
406 	struct completion *waiting;
407 
408 	/* Bounce SCSI-initiated commands to the SCSI EH */
409 	if (qc->scsicmd) {
410 		scsi_req_abort_cmd(qc->scsicmd);
411 		scsi_schedule_eh(qc->scsicmd->device->host);
412 		return;
413 	}
414 
415 	/* Internal command, fake a timeout and complete. */
416 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
417 	qc->flags |= ATA_QCFLAG_FAILED;
418 	qc->err_mask |= AC_ERR_TIMEOUT;
419 	waiting = qc->private_data;
420 	complete(waiting);
421 }
422 
423 static void sas_task_timedout(unsigned long _task)
424 {
425 	struct sas_task *task = (void *) _task;
426 	unsigned long flags;
427 
428 	spin_lock_irqsave(&task->task_state_lock, flags);
429 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
430 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
431 	spin_unlock_irqrestore(&task->task_state_lock, flags);
432 
433 	complete(&task->completion);
434 }
435 
436 static void sas_disc_task_done(struct sas_task *task)
437 {
438 	if (!del_timer(&task->timer))
439 		return;
440 	complete(&task->completion);
441 }
442 
443 #define SAS_DEV_TIMEOUT 10
444 
445 /**
446  * sas_execute_task -- Basic task processing for discovery
447  * @task: the task to be executed
448  * @buffer: pointer to buffer to do I/O
449  * @size: size of @buffer
450  * @dma_dir: DMA direction.  DMA_xxx
451  */
452 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
453 			    enum dma_data_direction dma_dir)
454 {
455 	int res = 0;
456 	struct scatterlist *scatter = NULL;
457 	struct task_status_struct *ts = &task->task_status;
458 	int num_scatter = 0;
459 	int retries = 0;
460 	struct sas_internal *i =
461 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
462 
463 	if (dma_dir != DMA_NONE) {
464 		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
465 		if (!scatter)
466 			goto out;
467 
468 		sg_init_one(scatter, buffer, size);
469 		num_scatter = 1;
470 	}
471 
472 	task->task_proto = task->dev->tproto;
473 	task->scatter = scatter;
474 	task->num_scatter = num_scatter;
475 	task->total_xfer_len = size;
476 	task->data_dir = dma_dir;
477 	task->task_done = sas_disc_task_done;
478 	if (dma_dir != DMA_NONE &&
479 	    sas_protocol_ata(task->task_proto)) {
480 		task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
481 					       task->scatter,
482 					       task->num_scatter,
483 					       task->data_dir);
484 	}
485 
486 	for (retries = 0; retries < 5; retries++) {
487 		task->task_state_flags = SAS_TASK_STATE_PENDING;
488 		init_completion(&task->completion);
489 
490 		task->timer.data = (unsigned long) task;
491 		task->timer.function = sas_task_timedout;
492 		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
493 		add_timer(&task->timer);
494 
495 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
496 		if (res) {
497 			del_timer(&task->timer);
498 			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
499 				    res);
500 			goto ex_err;
501 		}
502 		wait_for_completion(&task->completion);
503 		res = -ETASK;
504 		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
505 			int res2;
506 			SAS_DPRINTK("task aborted, flags:0x%x\n",
507 				    task->task_state_flags);
508 			res2 = i->dft->lldd_abort_task(task);
509 			SAS_DPRINTK("came back from abort task\n");
510 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
511 				if (res2 == TMF_RESP_FUNC_COMPLETE)
512 					continue; /* Retry the task */
513 				else
514 					goto ex_err;
515 			}
516 		}
517 		if (task->task_status.stat == SAM_BUSY ||
518 			   task->task_status.stat == SAM_TASK_SET_FULL ||
519 			   task->task_status.stat == SAS_QUEUE_FULL) {
520 			SAS_DPRINTK("task: q busy, sleeping...\n");
521 			schedule_timeout_interruptible(HZ);
522 		} else if (task->task_status.stat == SAM_CHECK_COND) {
523 			struct scsi_sense_hdr shdr;
524 
525 			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
526 						  &shdr)) {
527 				SAS_DPRINTK("couldn't normalize sense\n");
528 				continue;
529 			}
530 			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
531 			    (shdr.sense_key == 2 && shdr.asc == 4 &&
532 			     shdr.ascq == 1)) {
533 				SAS_DPRINTK("device %016llx LUN: %016llx "
534 					    "powering up or not ready yet, "
535 					    "sleeping...\n",
536 					    SAS_ADDR(task->dev->sas_addr),
537 					    SAS_ADDR(task->ssp_task.LUN));
538 
539 				schedule_timeout_interruptible(5*HZ);
540 			} else if (shdr.sense_key == 1) {
541 				res = 0;
542 				break;
543 			} else if (shdr.sense_key == 5) {
544 				break;
545 			} else {
546 				SAS_DPRINTK("dev %016llx LUN: %016llx "
547 					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
548 					    "\n",
549 					    SAS_ADDR(task->dev->sas_addr),
550 					    SAS_ADDR(task->ssp_task.LUN),
551 					    shdr.sense_key,
552 					    shdr.asc, shdr.ascq);
553 			}
554 		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
555 			   task->task_status.stat != SAM_GOOD) {
556 			SAS_DPRINTK("task finished with resp:0x%x, "
557 				    "stat:0x%x\n",
558 				    task->task_status.resp,
559 				    task->task_status.stat);
560 			goto ex_err;
561 		} else {
562 			res = 0;
563 			break;
564 		}
565 	}
566 ex_err:
567 	if (dma_dir != DMA_NONE) {
568 		if (sas_protocol_ata(task->task_proto))
569 			dma_unmap_sg(task->dev->port->ha->dev,
570 				     task->scatter, task->num_scatter,
571 				     task->data_dir);
572 		kfree(scatter);
573 	}
574 out:
575 	return res;
576 }
577 
578 /* ---------- SATA ---------- */
579 
580 static void sas_get_ata_command_set(struct domain_device *dev)
581 {
582 	struct dev_to_host_fis *fis =
583 		(struct dev_to_host_fis *) dev->frame_rcvd;
584 
585 	if ((fis->sector_count == 1 && /* ATA */
586 	     fis->lbal         == 1 &&
587 	     fis->lbam         == 0 &&
588 	     fis->lbah         == 0 &&
589 	     fis->device       == 0)
590 	    ||
591 	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
592 	     fis->lbal         == 0 &&
593 	     fis->lbam         == 0xCE &&
594 	     fis->lbah         == 0xAA &&
595 	     (fis->device & ~0x10) == 0))
596 
597 		dev->sata_dev.command_set = ATA_COMMAND_SET;
598 
599 	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
600 		  fis->lbal             == 1 &&
601 		  fis->byte_count_low   == 0x14 &&
602 		  fis->byte_count_high  == 0xEB &&
603 		  (fis->device & ~0x10) == 0))
604 
605 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
606 
607 	else if ((fis->sector_count == 1 && /* SEMB */
608 		  fis->lbal         == 1 &&
609 		  fis->lbam         == 0x3C &&
610 		  fis->lbah         == 0xC3 &&
611 		  fis->device       == 0)
612 		||
613 		 (fis->interrupt_reason == 1 &&	/* SATA PM */
614 		  fis->lbal             == 1 &&
615 		  fis->byte_count_low   == 0x69 &&
616 		  fis->byte_count_high  == 0x96 &&
617 		  (fis->device & ~0x10) == 0))
618 
619 		/* Treat it as a superset? */
620 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
621 }
622 
623 /**
624  * sas_issue_ata_cmd -- Basic SATA command processing for discovery
625  * @dev: the device to send the command to
626  * @command: the command register
627  * @features: the features register
628  * @buffer: pointer to buffer to do I/O
629  * @size: size of @buffer
630  * @dma_dir: DMA direction.  DMA_xxx
631  */
632 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
633 			     u8 features, void *buffer, int size,
634 			     enum dma_data_direction dma_dir)
635 {
636 	int res = 0;
637 	struct sas_task *task;
638 	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
639 		&dev->frame_rcvd[0];
640 
641 	res = -ENOMEM;
642 	task = sas_alloc_task(GFP_KERNEL);
643 	if (!task)
644 		goto out;
645 
646 	task->dev = dev;
647 
648 	task->ata_task.fis.fis_type = 0x27;
649 	task->ata_task.fis.command = command;
650 	task->ata_task.fis.features = features;
651 	task->ata_task.fis.device = d2h_fis->device;
652 	task->ata_task.retry_count = 1;
653 
654 	res = sas_execute_task(task, buffer, size, dma_dir);
655 
656 	sas_free_task(task);
657 out:
658 	return res;
659 }
660 
661 static void sas_sata_propagate_sas_addr(struct domain_device *dev)
662 {
663 	unsigned long flags;
664 	struct asd_sas_port *port = dev->port;
665 	struct asd_sas_phy  *phy;
666 
667 	BUG_ON(dev->parent);
668 
669 	memcpy(port->attached_sas_addr, dev->sas_addr, SAS_ADDR_SIZE);
670 	spin_lock_irqsave(&port->phy_list_lock, flags);
671 	list_for_each_entry(phy, &port->phy_list, port_phy_el)
672 		memcpy(phy->attached_sas_addr, dev->sas_addr, SAS_ADDR_SIZE);
673 	spin_unlock_irqrestore(&port->phy_list_lock, flags);
674 }
675 
676 #define ATA_IDENTIFY_DEV         0xEC
677 #define ATA_IDENTIFY_PACKET_DEV  0xA1
678 #define ATA_SET_FEATURES         0xEF
679 #define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
680 
681 /**
682  * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
683  * @dev: STP/SATA device of interest (ATA/ATAPI)
684  *
685  * The LLDD has already been notified of this device, so that we can
686  * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
687  * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
688  * performance for this device.
689  */
690 static int sas_discover_sata_dev(struct domain_device *dev)
691 {
692 	int     res;
693 	__le16  *identify_x;
694 	u8      command;
695 
696 	identify_x = kzalloc(512, GFP_KERNEL);
697 	if (!identify_x)
698 		return -ENOMEM;
699 
700 	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
701 		dev->sata_dev.identify_device = identify_x;
702 		command = ATA_IDENTIFY_DEV;
703 	} else {
704 		dev->sata_dev.identify_packet_device = identify_x;
705 		command = ATA_IDENTIFY_PACKET_DEV;
706 	}
707 
708 	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
709 				DMA_FROM_DEVICE);
710 	if (res)
711 		goto out_err;
712 
713 	/* lives on the media? */
714 	if (le16_to_cpu(identify_x[0]) & 4) {
715 		/* incomplete response */
716 		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
717 			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
718 		if (!le16_to_cpu(identify_x[83] & (1<<6)))
719 			goto cont1;
720 		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
721 					ATA_FEATURE_PUP_STBY_SPIN_UP,
722 					NULL, 0, DMA_NONE);
723 		if (res)
724 			goto cont1;
725 
726 		schedule_timeout_interruptible(5*HZ); /* More time? */
727 		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
728 					DMA_FROM_DEVICE);
729 		if (res)
730 			goto out_err;
731 	}
732 cont1:
733 	/* Get WWN */
734 	if (dev->port->oob_mode != SATA_OOB_MODE) {
735 		memcpy(dev->sas_addr, dev->sata_dev.rps_resp.rps.stp_sas_addr,
736 		       SAS_ADDR_SIZE);
737 	} else if (dev->sata_dev.command_set == ATA_COMMAND_SET &&
738 		   (le16_to_cpu(dev->sata_dev.identify_device[108]) & 0xF000)
739 		   == 0x5000) {
740 		int i;
741 
742 		for (i = 0; i < 4; i++) {
743 			dev->sas_addr[2*i] =
744 	     (le16_to_cpu(dev->sata_dev.identify_device[108+i]) & 0xFF00) >> 8;
745 			dev->sas_addr[2*i+1] =
746 	      le16_to_cpu(dev->sata_dev.identify_device[108+i]) & 0x00FF;
747 		}
748 	}
749 	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
750 	if (!dev->parent)
751 		sas_sata_propagate_sas_addr(dev);
752 
753 	/* XXX Hint: register this SATA device with SATL.
754 	   When this returns, dev->sata_dev->lu is alive and
755 	   present.
756 	sas_satl_register_dev(dev);
757 	*/
758 
759 	sas_fill_in_rphy(dev, dev->rphy);
760 
761 	return 0;
762 out_err:
763 	dev->sata_dev.identify_packet_device = NULL;
764 	dev->sata_dev.identify_device = NULL;
765 	kfree(identify_x);
766 	return res;
767 }
768 
769 static int sas_discover_sata_pm(struct domain_device *dev)
770 {
771 	return -ENODEV;
772 }
773 
774 /**
775  * sas_discover_sata -- discover an STP/SATA domain device
776  * @dev: pointer to struct domain_device of interest
777  *
778  * First we notify the LLDD of this device, so we can send frames to
779  * it.  Then depending on the type of device we call the appropriate
780  * discover functions.  Once device discover is done, we notify the
781  * LLDD so that it can fine-tune its parameters for the device, by
782  * removing it and then adding it.  That is, the second time around,
783  * the driver would have certain fields, that it is looking at, set.
784  * Finally we initialize the kobj so that the device can be added to
785  * the system at registration time.  Devices directly attached to a HA
786  * port, have no parents.  All other devices do, and should have their
787  * "parent" pointer set appropriately before calling this function.
788  */
789 int sas_discover_sata(struct domain_device *dev)
790 {
791 	int res;
792 
793 	sas_get_ata_command_set(dev);
794 
795 	res = sas_notify_lldd_dev_found(dev);
796 	if (res)
797 		return res;
798 
799 	switch (dev->dev_type) {
800 	case SATA_DEV:
801 		res = sas_discover_sata_dev(dev);
802 		break;
803 	case SATA_PM:
804 		res = sas_discover_sata_pm(dev);
805 		break;
806 	default:
807 		break;
808 	}
809 	sas_notify_lldd_dev_gone(dev);
810 	if (!res) {
811 		sas_notify_lldd_dev_found(dev);
812 		res = sas_rphy_add(dev->rphy);
813 	}
814 
815 	return res;
816 }
817