xref: /openbmc/linux/drivers/scsi/libsas/sas_ata.c (revision 4800cd83)
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 #include <linux/slab.h>
26 
27 #include <scsi/sas_ata.h>
28 #include "sas_internal.h"
29 #include <scsi/scsi_host.h>
30 #include <scsi/scsi_device.h>
31 #include <scsi/scsi_tcq.h>
32 #include <scsi/scsi.h>
33 #include <scsi/scsi_transport.h>
34 #include <scsi/scsi_transport_sas.h>
35 #include "../scsi_sas_internal.h"
36 #include "../scsi_transport_api.h"
37 #include <scsi/scsi_eh.h>
38 
39 static enum ata_completion_errors sas_to_ata_err(struct task_status_struct *ts)
40 {
41 	/* Cheesy attempt to translate SAS errors into ATA.  Hah! */
42 
43 	/* transport error */
44 	if (ts->resp == SAS_TASK_UNDELIVERED)
45 		return AC_ERR_ATA_BUS;
46 
47 	/* ts->resp == SAS_TASK_COMPLETE */
48 	/* task delivered, what happened afterwards? */
49 	switch (ts->stat) {
50 		case SAS_DEV_NO_RESPONSE:
51 			return AC_ERR_TIMEOUT;
52 
53 		case SAS_INTERRUPTED:
54 		case SAS_PHY_DOWN:
55 		case SAS_NAK_R_ERR:
56 			return AC_ERR_ATA_BUS;
57 
58 
59 		case SAS_DATA_UNDERRUN:
60 			/*
61 			 * Some programs that use the taskfile interface
62 			 * (smartctl in particular) can cause underrun
63 			 * problems.  Ignore these errors, perhaps at our
64 			 * peril.
65 			 */
66 			return 0;
67 
68 		case SAS_DATA_OVERRUN:
69 		case SAS_QUEUE_FULL:
70 		case SAS_DEVICE_UNKNOWN:
71 		case SAS_SG_ERR:
72 			return AC_ERR_INVALID;
73 
74 		case SAM_STAT_CHECK_CONDITION:
75 		case SAS_OPEN_TO:
76 		case SAS_OPEN_REJECT:
77 			SAS_DPRINTK("%s: Saw error %d.  What to do?\n",
78 				    __func__, ts->stat);
79 			return AC_ERR_OTHER;
80 
81 		case SAS_ABORTED_TASK:
82 			return AC_ERR_DEV;
83 
84 		case SAS_PROTO_RESPONSE:
85 			/* This means the ending_fis has the error
86 			 * value; return 0 here to collect it */
87 			return 0;
88 		default:
89 			return 0;
90 	}
91 }
92 
93 static void sas_ata_task_done(struct sas_task *task)
94 {
95 	struct ata_queued_cmd *qc = task->uldd_task;
96 	struct domain_device *dev;
97 	struct task_status_struct *stat = &task->task_status;
98 	struct ata_task_resp *resp = (struct ata_task_resp *)stat->buf;
99 	struct sas_ha_struct *sas_ha;
100 	enum ata_completion_errors ac;
101 	unsigned long flags;
102 
103 	if (!qc)
104 		goto qc_already_gone;
105 
106 	dev = qc->ap->private_data;
107 	sas_ha = dev->port->ha;
108 
109 	spin_lock_irqsave(dev->sata_dev.ap->lock, flags);
110 	if (stat->stat == SAS_PROTO_RESPONSE || stat->stat == SAM_STAT_GOOD) {
111 		ata_tf_from_fis(resp->ending_fis, &dev->sata_dev.tf);
112 		qc->err_mask |= ac_err_mask(dev->sata_dev.tf.command);
113 		dev->sata_dev.sstatus = resp->sstatus;
114 		dev->sata_dev.serror = resp->serror;
115 		dev->sata_dev.scontrol = resp->scontrol;
116 	} else if (stat->stat != SAM_STAT_GOOD) {
117 		ac = sas_to_ata_err(stat);
118 		if (ac) {
119 			SAS_DPRINTK("%s: SAS error %x\n", __func__,
120 				    stat->stat);
121 			/* We saw a SAS error. Send a vague error. */
122 			qc->err_mask = ac;
123 			dev->sata_dev.tf.feature = 0x04; /* status err */
124 			dev->sata_dev.tf.command = ATA_ERR;
125 		}
126 	}
127 
128 	qc->lldd_task = NULL;
129 	if (qc->scsicmd)
130 		ASSIGN_SAS_TASK(qc->scsicmd, NULL);
131 	ata_qc_complete(qc);
132 	spin_unlock_irqrestore(dev->sata_dev.ap->lock, flags);
133 
134 	/*
135 	 * If the sas_task has an ata qc, a scsi_cmnd and the aborted
136 	 * flag is set, then we must have come in via the libsas EH
137 	 * functions.  When we exit this function, we need to put the
138 	 * scsi_cmnd on the list of finished errors.  The ata_qc_complete
139 	 * call cleans up the libata side of things but we're protected
140 	 * from the scsi_cmnd going away because the scsi_cmnd is owned
141 	 * by the EH, making libata's call to scsi_done a NOP.
142 	 */
143 	spin_lock_irqsave(&task->task_state_lock, flags);
144 	if (qc->scsicmd && task->task_state_flags & SAS_TASK_STATE_ABORTED)
145 		scsi_eh_finish_cmd(qc->scsicmd, &sas_ha->eh_done_q);
146 	spin_unlock_irqrestore(&task->task_state_lock, flags);
147 
148 qc_already_gone:
149 	list_del_init(&task->list);
150 	sas_free_task(task);
151 }
152 
153 static unsigned int sas_ata_qc_issue(struct ata_queued_cmd *qc)
154 {
155 	int res;
156 	struct sas_task *task;
157 	struct domain_device *dev = qc->ap->private_data;
158 	struct sas_ha_struct *sas_ha = dev->port->ha;
159 	struct Scsi_Host *host = sas_ha->core.shost;
160 	struct sas_internal *i = to_sas_internal(host->transportt);
161 	struct scatterlist *sg;
162 	unsigned int xfer = 0;
163 	unsigned int si;
164 
165 	/* If the device fell off, no sense in issuing commands */
166 	if (dev->gone)
167 		return AC_ERR_SYSTEM;
168 
169 	task = sas_alloc_task(GFP_ATOMIC);
170 	if (!task)
171 		return AC_ERR_SYSTEM;
172 	task->dev = dev;
173 	task->task_proto = SAS_PROTOCOL_STP;
174 	task->task_done = sas_ata_task_done;
175 
176 	if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
177 	    qc->tf.command == ATA_CMD_FPDMA_READ) {
178 		/* Need to zero out the tag libata assigned us */
179 		qc->tf.nsect = 0;
180 	}
181 
182 	ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
183 	task->uldd_task = qc;
184 	if (ata_is_atapi(qc->tf.protocol)) {
185 		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
186 		task->total_xfer_len = qc->nbytes;
187 		task->num_scatter = qc->n_elem;
188 	} else {
189 		for_each_sg(qc->sg, sg, qc->n_elem, si)
190 			xfer += sg->length;
191 
192 		task->total_xfer_len = xfer;
193 		task->num_scatter = si;
194 	}
195 
196 	task->data_dir = qc->dma_dir;
197 	task->scatter = qc->sg;
198 	task->ata_task.retry_count = 1;
199 	task->task_state_flags = SAS_TASK_STATE_PENDING;
200 	qc->lldd_task = task;
201 
202 	switch (qc->tf.protocol) {
203 	case ATA_PROT_NCQ:
204 		task->ata_task.use_ncq = 1;
205 		/* fall through */
206 	case ATAPI_PROT_DMA:
207 	case ATA_PROT_DMA:
208 		task->ata_task.dma_xfer = 1;
209 		break;
210 	}
211 
212 	if (qc->scsicmd)
213 		ASSIGN_SAS_TASK(qc->scsicmd, task);
214 
215 	if (sas_ha->lldd_max_execute_num < 2)
216 		res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
217 	else
218 		res = sas_queue_up(task);
219 
220 	/* Examine */
221 	if (res) {
222 		SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
223 
224 		if (qc->scsicmd)
225 			ASSIGN_SAS_TASK(qc->scsicmd, NULL);
226 		sas_free_task(task);
227 		return AC_ERR_SYSTEM;
228 	}
229 
230 	return 0;
231 }
232 
233 static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
234 {
235 	struct domain_device *dev = qc->ap->private_data;
236 
237 	memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
238 	return true;
239 }
240 
241 static void sas_ata_phy_reset(struct ata_port *ap)
242 {
243 	struct domain_device *dev = ap->private_data;
244 	struct sas_internal *i =
245 		to_sas_internal(dev->port->ha->core.shost->transportt);
246 	int res = TMF_RESP_FUNC_FAILED;
247 
248 	if (i->dft->lldd_I_T_nexus_reset)
249 		res = i->dft->lldd_I_T_nexus_reset(dev);
250 
251 	if (res != TMF_RESP_FUNC_COMPLETE)
252 		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);
253 
254 	switch (dev->sata_dev.command_set) {
255 		case ATA_COMMAND_SET:
256 			SAS_DPRINTK("%s: Found ATA device.\n", __func__);
257 			ap->link.device[0].class = ATA_DEV_ATA;
258 			break;
259 		case ATAPI_COMMAND_SET:
260 			SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
261 			ap->link.device[0].class = ATA_DEV_ATAPI;
262 			break;
263 		default:
264 			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
265 				    __func__,
266 				    dev->sata_dev.command_set);
267 			ap->link.device[0].class = ATA_DEV_UNKNOWN;
268 			break;
269 	}
270 
271 	ap->cbl = ATA_CBL_SATA;
272 }
273 
274 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
275 {
276 	if (qc->flags & ATA_QCFLAG_FAILED)
277 		qc->err_mask |= AC_ERR_OTHER;
278 
279 	if (qc->err_mask) {
280 		/*
281 		 * Find the sas_task and kill it.  By this point,
282 		 * libata has decided to kill the qc, so we needn't
283 		 * bother with sas_ata_task_done.  But we still
284 		 * ought to abort the task.
285 		 */
286 		struct sas_task *task = qc->lldd_task;
287 		unsigned long flags;
288 
289 		qc->lldd_task = NULL;
290 		if (task) {
291 			/* Should this be a AT(API) device reset? */
292 			spin_lock_irqsave(&task->task_state_lock, flags);
293 			task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
294 			spin_unlock_irqrestore(&task->task_state_lock, flags);
295 
296 			task->uldd_task = NULL;
297 			__sas_task_abort(task);
298 		}
299 	}
300 }
301 
302 static int sas_ata_scr_write(struct ata_link *link, unsigned int sc_reg_in,
303 			      u32 val)
304 {
305 	struct domain_device *dev = link->ap->private_data;
306 
307 	SAS_DPRINTK("STUB %s\n", __func__);
308 	switch (sc_reg_in) {
309 		case SCR_STATUS:
310 			dev->sata_dev.sstatus = val;
311 			break;
312 		case SCR_CONTROL:
313 			dev->sata_dev.scontrol = val;
314 			break;
315 		case SCR_ERROR:
316 			dev->sata_dev.serror = val;
317 			break;
318 		case SCR_ACTIVE:
319 			dev->sata_dev.ap->link.sactive = val;
320 			break;
321 		default:
322 			return -EINVAL;
323 	}
324 	return 0;
325 }
326 
327 static int sas_ata_scr_read(struct ata_link *link, unsigned int sc_reg_in,
328 			    u32 *val)
329 {
330 	struct domain_device *dev = link->ap->private_data;
331 
332 	SAS_DPRINTK("STUB %s\n", __func__);
333 	switch (sc_reg_in) {
334 		case SCR_STATUS:
335 			*val = dev->sata_dev.sstatus;
336 			return 0;
337 		case SCR_CONTROL:
338 			*val = dev->sata_dev.scontrol;
339 			return 0;
340 		case SCR_ERROR:
341 			*val = dev->sata_dev.serror;
342 			return 0;
343 		case SCR_ACTIVE:
344 			*val = dev->sata_dev.ap->link.sactive;
345 			return 0;
346 		default:
347 			return -EINVAL;
348 	}
349 }
350 
351 static struct ata_port_operations sas_sata_ops = {
352 	.phy_reset		= sas_ata_phy_reset,
353 	.post_internal_cmd	= sas_ata_post_internal,
354 	.qc_defer               = ata_std_qc_defer,
355 	.qc_prep		= ata_noop_qc_prep,
356 	.qc_issue		= sas_ata_qc_issue,
357 	.qc_fill_rtf		= sas_ata_qc_fill_rtf,
358 	.port_start		= ata_sas_port_start,
359 	.port_stop		= ata_sas_port_stop,
360 	.scr_read		= sas_ata_scr_read,
361 	.scr_write		= sas_ata_scr_write
362 };
363 
364 static struct ata_port_info sata_port_info = {
365 	.flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY | ATA_FLAG_SATA_RESET |
366 		ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
367 	.pio_mask = 0x1f, /* PIO0-4 */
368 	.mwdma_mask = 0x07, /* MWDMA0-2 */
369 	.udma_mask = ATA_UDMA6,
370 	.port_ops = &sas_sata_ops
371 };
372 
373 int sas_ata_init_host_and_port(struct domain_device *found_dev,
374 			       struct scsi_target *starget)
375 {
376 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
377 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
378 	struct ata_port *ap;
379 
380 	ata_host_init(&found_dev->sata_dev.ata_host,
381 		      ha->dev,
382 		      sata_port_info.flags,
383 		      &sas_sata_ops);
384 	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
385 				&sata_port_info,
386 				shost);
387 	if (!ap) {
388 		SAS_DPRINTK("ata_sas_port_alloc failed.\n");
389 		return -ENODEV;
390 	}
391 
392 	ap->private_data = found_dev;
393 	ap->cbl = ATA_CBL_SATA;
394 	ap->scsi_host = shost;
395 	found_dev->sata_dev.ap = ap;
396 
397 	return 0;
398 }
399 
400 void sas_ata_task_abort(struct sas_task *task)
401 {
402 	struct ata_queued_cmd *qc = task->uldd_task;
403 	struct completion *waiting;
404 
405 	/* Bounce SCSI-initiated commands to the SCSI EH */
406 	if (qc->scsicmd) {
407 		struct request_queue *q = qc->scsicmd->device->request_queue;
408 		unsigned long flags;
409 
410 		spin_lock_irqsave(q->queue_lock, flags);
411 		blk_abort_request(qc->scsicmd->request);
412 		spin_unlock_irqrestore(q->queue_lock, flags);
413 		scsi_schedule_eh(qc->scsicmd->device->host);
414 		return;
415 	}
416 
417 	/* Internal command, fake a timeout and complete. */
418 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
419 	qc->flags |= ATA_QCFLAG_FAILED;
420 	qc->err_mask |= AC_ERR_TIMEOUT;
421 	waiting = qc->private_data;
422 	complete(waiting);
423 }
424 
425 static void sas_task_timedout(unsigned long _task)
426 {
427 	struct sas_task *task = (void *) _task;
428 	unsigned long flags;
429 
430 	spin_lock_irqsave(&task->task_state_lock, flags);
431 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
432 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
433 	spin_unlock_irqrestore(&task->task_state_lock, flags);
434 
435 	complete(&task->completion);
436 }
437 
438 static void sas_disc_task_done(struct sas_task *task)
439 {
440 	if (!del_timer(&task->timer))
441 		return;
442 	complete(&task->completion);
443 }
444 
445 #define SAS_DEV_TIMEOUT 10
446 
447 /**
448  * sas_execute_task -- Basic task processing for discovery
449  * @task: the task to be executed
450  * @buffer: pointer to buffer to do I/O
451  * @size: size of @buffer
452  * @dma_dir: DMA direction.  DMA_xxx
453  */
454 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
455 			    enum dma_data_direction dma_dir)
456 {
457 	int res = 0;
458 	struct scatterlist *scatter = NULL;
459 	struct task_status_struct *ts = &task->task_status;
460 	int num_scatter = 0;
461 	int retries = 0;
462 	struct sas_internal *i =
463 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
464 
465 	if (dma_dir != DMA_NONE) {
466 		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
467 		if (!scatter)
468 			goto out;
469 
470 		sg_init_one(scatter, buffer, size);
471 		num_scatter = 1;
472 	}
473 
474 	task->task_proto = task->dev->tproto;
475 	task->scatter = scatter;
476 	task->num_scatter = num_scatter;
477 	task->total_xfer_len = size;
478 	task->data_dir = dma_dir;
479 	task->task_done = sas_disc_task_done;
480 	if (dma_dir != DMA_NONE &&
481 	    sas_protocol_ata(task->task_proto)) {
482 		task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
483 					       task->scatter,
484 					       task->num_scatter,
485 					       task->data_dir);
486 	}
487 
488 	for (retries = 0; retries < 5; retries++) {
489 		task->task_state_flags = SAS_TASK_STATE_PENDING;
490 		init_completion(&task->completion);
491 
492 		task->timer.data = (unsigned long) task;
493 		task->timer.function = sas_task_timedout;
494 		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
495 		add_timer(&task->timer);
496 
497 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
498 		if (res) {
499 			del_timer(&task->timer);
500 			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
501 				    res);
502 			goto ex_err;
503 		}
504 		wait_for_completion(&task->completion);
505 		res = -ECOMM;
506 		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
507 			int res2;
508 			SAS_DPRINTK("task aborted, flags:0x%x\n",
509 				    task->task_state_flags);
510 			res2 = i->dft->lldd_abort_task(task);
511 			SAS_DPRINTK("came back from abort task\n");
512 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
513 				if (res2 == TMF_RESP_FUNC_COMPLETE)
514 					continue; /* Retry the task */
515 				else
516 					goto ex_err;
517 			}
518 		}
519 		if (task->task_status.stat == SAM_STAT_BUSY ||
520 			   task->task_status.stat == SAM_STAT_TASK_SET_FULL ||
521 			   task->task_status.stat == SAS_QUEUE_FULL) {
522 			SAS_DPRINTK("task: q busy, sleeping...\n");
523 			schedule_timeout_interruptible(HZ);
524 		} else if (task->task_status.stat == SAM_STAT_CHECK_CONDITION) {
525 			struct scsi_sense_hdr shdr;
526 
527 			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
528 						  &shdr)) {
529 				SAS_DPRINTK("couldn't normalize sense\n");
530 				continue;
531 			}
532 			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
533 			    (shdr.sense_key == 2 && shdr.asc == 4 &&
534 			     shdr.ascq == 1)) {
535 				SAS_DPRINTK("device %016llx LUN: %016llx "
536 					    "powering up or not ready yet, "
537 					    "sleeping...\n",
538 					    SAS_ADDR(task->dev->sas_addr),
539 					    SAS_ADDR(task->ssp_task.LUN));
540 
541 				schedule_timeout_interruptible(5*HZ);
542 			} else if (shdr.sense_key == 1) {
543 				res = 0;
544 				break;
545 			} else if (shdr.sense_key == 5) {
546 				break;
547 			} else {
548 				SAS_DPRINTK("dev %016llx LUN: %016llx "
549 					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
550 					    "\n",
551 					    SAS_ADDR(task->dev->sas_addr),
552 					    SAS_ADDR(task->ssp_task.LUN),
553 					    shdr.sense_key,
554 					    shdr.asc, shdr.ascq);
555 			}
556 		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
557 			   task->task_status.stat != SAM_STAT_GOOD) {
558 			SAS_DPRINTK("task finished with resp:0x%x, "
559 				    "stat:0x%x\n",
560 				    task->task_status.resp,
561 				    task->task_status.stat);
562 			goto ex_err;
563 		} else {
564 			res = 0;
565 			break;
566 		}
567 	}
568 ex_err:
569 	if (dma_dir != DMA_NONE) {
570 		if (sas_protocol_ata(task->task_proto))
571 			dma_unmap_sg(task->dev->port->ha->dev,
572 				     task->scatter, task->num_scatter,
573 				     task->data_dir);
574 		kfree(scatter);
575 	}
576 out:
577 	return res;
578 }
579 
580 /* ---------- SATA ---------- */
581 
582 static void sas_get_ata_command_set(struct domain_device *dev)
583 {
584 	struct dev_to_host_fis *fis =
585 		(struct dev_to_host_fis *) dev->frame_rcvd;
586 
587 	if ((fis->sector_count == 1 && /* ATA */
588 	     fis->lbal         == 1 &&
589 	     fis->lbam         == 0 &&
590 	     fis->lbah         == 0 &&
591 	     fis->device       == 0)
592 	    ||
593 	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
594 	     fis->lbal         == 0 &&
595 	     fis->lbam         == 0xCE &&
596 	     fis->lbah         == 0xAA &&
597 	     (fis->device & ~0x10) == 0))
598 
599 		dev->sata_dev.command_set = ATA_COMMAND_SET;
600 
601 	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
602 		  fis->lbal             == 1 &&
603 		  fis->byte_count_low   == 0x14 &&
604 		  fis->byte_count_high  == 0xEB &&
605 		  (fis->device & ~0x10) == 0))
606 
607 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
608 
609 	else if ((fis->sector_count == 1 && /* SEMB */
610 		  fis->lbal         == 1 &&
611 		  fis->lbam         == 0x3C &&
612 		  fis->lbah         == 0xC3 &&
613 		  fis->device       == 0)
614 		||
615 		 (fis->interrupt_reason == 1 &&	/* SATA PM */
616 		  fis->lbal             == 1 &&
617 		  fis->byte_count_low   == 0x69 &&
618 		  fis->byte_count_high  == 0x96 &&
619 		  (fis->device & ~0x10) == 0))
620 
621 		/* Treat it as a superset? */
622 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
623 }
624 
625 /**
626  * sas_issue_ata_cmd -- Basic SATA command processing for discovery
627  * @dev: the device to send the command to
628  * @command: the command register
629  * @features: the features register
630  * @buffer: pointer to buffer to do I/O
631  * @size: size of @buffer
632  * @dma_dir: DMA direction.  DMA_xxx
633  */
634 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
635 			     u8 features, void *buffer, int size,
636 			     enum dma_data_direction dma_dir)
637 {
638 	int res = 0;
639 	struct sas_task *task;
640 	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
641 		&dev->frame_rcvd[0];
642 
643 	res = -ENOMEM;
644 	task = sas_alloc_task(GFP_KERNEL);
645 	if (!task)
646 		goto out;
647 
648 	task->dev = dev;
649 
650 	task->ata_task.fis.fis_type = 0x27;
651 	task->ata_task.fis.command = command;
652 	task->ata_task.fis.features = features;
653 	task->ata_task.fis.device = d2h_fis->device;
654 	task->ata_task.retry_count = 1;
655 
656 	res = sas_execute_task(task, buffer, size, dma_dir);
657 
658 	sas_free_task(task);
659 out:
660 	return res;
661 }
662 
663 #define ATA_IDENTIFY_DEV         0xEC
664 #define ATA_IDENTIFY_PACKET_DEV  0xA1
665 #define ATA_SET_FEATURES         0xEF
666 #define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
667 
668 /**
669  * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
670  * @dev: STP/SATA device of interest (ATA/ATAPI)
671  *
672  * The LLDD has already been notified of this device, so that we can
673  * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
674  * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
675  * performance for this device.
676  */
677 static int sas_discover_sata_dev(struct domain_device *dev)
678 {
679 	int     res;
680 	__le16  *identify_x;
681 	u8      command;
682 
683 	identify_x = kzalloc(512, GFP_KERNEL);
684 	if (!identify_x)
685 		return -ENOMEM;
686 
687 	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
688 		dev->sata_dev.identify_device = identify_x;
689 		command = ATA_IDENTIFY_DEV;
690 	} else {
691 		dev->sata_dev.identify_packet_device = identify_x;
692 		command = ATA_IDENTIFY_PACKET_DEV;
693 	}
694 
695 	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
696 				DMA_FROM_DEVICE);
697 	if (res)
698 		goto out_err;
699 
700 	/* lives on the media? */
701 	if (le16_to_cpu(identify_x[0]) & 4) {
702 		/* incomplete response */
703 		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
704 			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
705 		if (!(identify_x[83] & cpu_to_le16(1<<6)))
706 			goto cont1;
707 		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
708 					ATA_FEATURE_PUP_STBY_SPIN_UP,
709 					NULL, 0, DMA_NONE);
710 		if (res)
711 			goto cont1;
712 
713 		schedule_timeout_interruptible(5*HZ); /* More time? */
714 		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
715 					DMA_FROM_DEVICE);
716 		if (res)
717 			goto out_err;
718 	}
719 cont1:
720 	/* XXX Hint: register this SATA device with SATL.
721 	   When this returns, dev->sata_dev->lu is alive and
722 	   present.
723 	sas_satl_register_dev(dev);
724 	*/
725 
726 	sas_fill_in_rphy(dev, dev->rphy);
727 
728 	return 0;
729 out_err:
730 	dev->sata_dev.identify_packet_device = NULL;
731 	dev->sata_dev.identify_device = NULL;
732 	kfree(identify_x);
733 	return res;
734 }
735 
736 static int sas_discover_sata_pm(struct domain_device *dev)
737 {
738 	return -ENODEV;
739 }
740 
741 /**
742  * sas_discover_sata -- discover an STP/SATA domain device
743  * @dev: pointer to struct domain_device of interest
744  *
745  * First we notify the LLDD of this device, so we can send frames to
746  * it.  Then depending on the type of device we call the appropriate
747  * discover functions.  Once device discover is done, we notify the
748  * LLDD so that it can fine-tune its parameters for the device, by
749  * removing it and then adding it.  That is, the second time around,
750  * the driver would have certain fields, that it is looking at, set.
751  * Finally we initialize the kobj so that the device can be added to
752  * the system at registration time.  Devices directly attached to a HA
753  * port, have no parents.  All other devices do, and should have their
754  * "parent" pointer set appropriately before calling this function.
755  */
756 int sas_discover_sata(struct domain_device *dev)
757 {
758 	int res;
759 
760 	sas_get_ata_command_set(dev);
761 
762 	res = sas_notify_lldd_dev_found(dev);
763 	if (res)
764 		return res;
765 
766 	switch (dev->dev_type) {
767 	case SATA_DEV:
768 		res = sas_discover_sata_dev(dev);
769 		break;
770 	case SATA_PM:
771 		res = sas_discover_sata_pm(dev);
772 		break;
773 	default:
774 		break;
775 	}
776 	sas_notify_lldd_dev_gone(dev);
777 	if (!res) {
778 		sas_notify_lldd_dev_found(dev);
779 		res = sas_rphy_add(dev->rphy);
780 	}
781 
782 	return res;
783 }
784