xref: /openbmc/linux/drivers/scsi/libsas/sas_ata.c (revision a1e58bbd)
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 xfer = 0;
162 	unsigned int si;
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 (ata_is_atapi(qc->tf.protocol)) {
180 		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
181 		task->total_xfer_len = qc->nbytes;
182 		task->num_scatter = qc->n_elem;
183 	} else {
184 		for_each_sg(qc->sg, sg, qc->n_elem, si)
185 			xfer += sg->length;
186 
187 		task->total_xfer_len = xfer;
188 		task->num_scatter = si;
189 	}
190 
191 	task->data_dir = qc->dma_dir;
192 	task->scatter = qc->sg;
193 	task->ata_task.retry_count = 1;
194 	task->task_state_flags = SAS_TASK_STATE_PENDING;
195 	qc->lldd_task = task;
196 
197 	switch (qc->tf.protocol) {
198 	case ATA_PROT_NCQ:
199 		task->ata_task.use_ncq = 1;
200 		/* fall through */
201 	case ATAPI_PROT_DMA:
202 	case ATA_PROT_DMA:
203 		task->ata_task.dma_xfer = 1;
204 		break;
205 	}
206 
207 	if (qc->scsicmd)
208 		ASSIGN_SAS_TASK(qc->scsicmd, task);
209 
210 	if (sas_ha->lldd_max_execute_num < 2)
211 		res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
212 	else
213 		res = sas_queue_up(task);
214 
215 	/* Examine */
216 	if (res) {
217 		SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
218 
219 		if (qc->scsicmd)
220 			ASSIGN_SAS_TASK(qc->scsicmd, NULL);
221 		sas_free_task(task);
222 		return AC_ERR_SYSTEM;
223 	}
224 
225 	return 0;
226 }
227 
228 static u8 sas_ata_check_status(struct ata_port *ap)
229 {
230 	struct domain_device *dev = ap->private_data;
231 	return dev->sata_dev.tf.command;
232 }
233 
234 static void sas_ata_phy_reset(struct ata_port *ap)
235 {
236 	struct domain_device *dev = ap->private_data;
237 	struct sas_internal *i =
238 		to_sas_internal(dev->port->ha->core.shost->transportt);
239 	int res = TMF_RESP_FUNC_FAILED;
240 
241 	if (i->dft->lldd_I_T_nexus_reset)
242 		res = i->dft->lldd_I_T_nexus_reset(dev);
243 
244 	if (res != TMF_RESP_FUNC_COMPLETE)
245 		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __FUNCTION__);
246 
247 	switch (dev->sata_dev.command_set) {
248 		case ATA_COMMAND_SET:
249 			SAS_DPRINTK("%s: Found ATA device.\n", __FUNCTION__);
250 			ap->link.device[0].class = ATA_DEV_ATA;
251 			break;
252 		case ATAPI_COMMAND_SET:
253 			SAS_DPRINTK("%s: Found ATAPI device.\n", __FUNCTION__);
254 			ap->link.device[0].class = ATA_DEV_ATAPI;
255 			break;
256 		default:
257 			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
258 				    __FUNCTION__,
259 				    dev->sata_dev.command_set);
260 			ap->link.device[0].class = ATA_DEV_UNKNOWN;
261 			break;
262 	}
263 
264 	ap->cbl = ATA_CBL_SATA;
265 }
266 
267 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
268 {
269 	if (qc->flags & ATA_QCFLAG_FAILED)
270 		qc->err_mask |= AC_ERR_OTHER;
271 
272 	if (qc->err_mask) {
273 		/*
274 		 * Find the sas_task and kill it.  By this point,
275 		 * libata has decided to kill the qc, so we needn't
276 		 * bother with sas_ata_task_done.  But we still
277 		 * ought to abort the task.
278 		 */
279 		struct sas_task *task = qc->lldd_task;
280 		unsigned long flags;
281 
282 		qc->lldd_task = NULL;
283 		if (task) {
284 			/* Should this be a AT(API) device reset? */
285 			spin_lock_irqsave(&task->task_state_lock, flags);
286 			task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
287 			spin_unlock_irqrestore(&task->task_state_lock, flags);
288 
289 			task->uldd_task = NULL;
290 			__sas_task_abort(task);
291 		}
292 	}
293 }
294 
295 static void sas_ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
296 {
297 	struct domain_device *dev = ap->private_data;
298 	memcpy(tf, &dev->sata_dev.tf, sizeof (*tf));
299 }
300 
301 static int sas_ata_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
302 			      u32 val)
303 {
304 	struct domain_device *dev = ap->private_data;
305 
306 	SAS_DPRINTK("STUB %s\n", __FUNCTION__);
307 	switch (sc_reg_in) {
308 		case SCR_STATUS:
309 			dev->sata_dev.sstatus = val;
310 			break;
311 		case SCR_CONTROL:
312 			dev->sata_dev.scontrol = val;
313 			break;
314 		case SCR_ERROR:
315 			dev->sata_dev.serror = val;
316 			break;
317 		case SCR_ACTIVE:
318 			dev->sata_dev.ap->link.sactive = val;
319 			break;
320 		default:
321 			return -EINVAL;
322 	}
323 	return 0;
324 }
325 
326 static int sas_ata_scr_read(struct ata_port *ap, unsigned int sc_reg_in,
327 			    u32 *val)
328 {
329 	struct domain_device *dev = ap->private_data;
330 
331 	SAS_DPRINTK("STUB %s\n", __FUNCTION__);
332 	switch (sc_reg_in) {
333 		case SCR_STATUS:
334 			*val = dev->sata_dev.sstatus;
335 			return 0;
336 		case SCR_CONTROL:
337 			*val = dev->sata_dev.scontrol;
338 			return 0;
339 		case SCR_ERROR:
340 			*val = dev->sata_dev.serror;
341 			return 0;
342 		case SCR_ACTIVE:
343 			*val = dev->sata_dev.ap->link.sactive;
344 			return 0;
345 		default:
346 			return -EINVAL;
347 	}
348 }
349 
350 static struct ata_port_operations sas_sata_ops = {
351 	.check_status		= sas_ata_check_status,
352 	.check_altstatus	= sas_ata_check_status,
353 	.dev_select		= ata_noop_dev_select,
354 	.phy_reset		= sas_ata_phy_reset,
355 	.post_internal_cmd	= sas_ata_post_internal,
356 	.tf_read		= sas_ata_tf_read,
357 	.qc_prep		= ata_noop_qc_prep,
358 	.qc_issue		= sas_ata_qc_issue,
359 	.port_start		= ata_sas_port_start,
360 	.port_stop		= ata_sas_port_stop,
361 	.scr_read		= sas_ata_scr_read,
362 	.scr_write		= sas_ata_scr_write
363 };
364 
365 static struct ata_port_info sata_port_info = {
366 	.flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY | ATA_FLAG_SATA_RESET |
367 		ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
368 	.pio_mask = 0x1f, /* PIO0-4 */
369 	.mwdma_mask = 0x07, /* MWDMA0-2 */
370 	.udma_mask = ATA_UDMA6,
371 	.port_ops = &sas_sata_ops
372 };
373 
374 int sas_ata_init_host_and_port(struct domain_device *found_dev,
375 			       struct scsi_target *starget)
376 {
377 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
378 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
379 	struct ata_port *ap;
380 
381 	ata_host_init(&found_dev->sata_dev.ata_host,
382 		      ha->dev,
383 		      sata_port_info.flags,
384 		      &sas_sata_ops);
385 	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
386 				&sata_port_info,
387 				shost);
388 	if (!ap) {
389 		SAS_DPRINTK("ata_sas_port_alloc failed.\n");
390 		return -ENODEV;
391 	}
392 
393 	ap->private_data = found_dev;
394 	ap->cbl = ATA_CBL_SATA;
395 	ap->scsi_host = shost;
396 	found_dev->sata_dev.ap = ap;
397 
398 	return 0;
399 }
400 
401 void sas_ata_task_abort(struct sas_task *task)
402 {
403 	struct ata_queued_cmd *qc = task->uldd_task;
404 	struct completion *waiting;
405 
406 	/* Bounce SCSI-initiated commands to the SCSI EH */
407 	if (qc->scsicmd) {
408 		scsi_req_abort_cmd(qc->scsicmd);
409 		scsi_schedule_eh(qc->scsicmd->device->host);
410 		return;
411 	}
412 
413 	/* Internal command, fake a timeout and complete. */
414 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
415 	qc->flags |= ATA_QCFLAG_FAILED;
416 	qc->err_mask |= AC_ERR_TIMEOUT;
417 	waiting = qc->private_data;
418 	complete(waiting);
419 }
420 
421 static void sas_task_timedout(unsigned long _task)
422 {
423 	struct sas_task *task = (void *) _task;
424 	unsigned long flags;
425 
426 	spin_lock_irqsave(&task->task_state_lock, flags);
427 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
428 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
429 	spin_unlock_irqrestore(&task->task_state_lock, flags);
430 
431 	complete(&task->completion);
432 }
433 
434 static void sas_disc_task_done(struct sas_task *task)
435 {
436 	if (!del_timer(&task->timer))
437 		return;
438 	complete(&task->completion);
439 }
440 
441 #define SAS_DEV_TIMEOUT 10
442 
443 /**
444  * sas_execute_task -- Basic task processing for discovery
445  * @task: the task to be executed
446  * @buffer: pointer to buffer to do I/O
447  * @size: size of @buffer
448  * @dma_dir: DMA direction.  DMA_xxx
449  */
450 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
451 			    enum dma_data_direction dma_dir)
452 {
453 	int res = 0;
454 	struct scatterlist *scatter = NULL;
455 	struct task_status_struct *ts = &task->task_status;
456 	int num_scatter = 0;
457 	int retries = 0;
458 	struct sas_internal *i =
459 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
460 
461 	if (dma_dir != DMA_NONE) {
462 		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
463 		if (!scatter)
464 			goto out;
465 
466 		sg_init_one(scatter, buffer, size);
467 		num_scatter = 1;
468 	}
469 
470 	task->task_proto = task->dev->tproto;
471 	task->scatter = scatter;
472 	task->num_scatter = num_scatter;
473 	task->total_xfer_len = size;
474 	task->data_dir = dma_dir;
475 	task->task_done = sas_disc_task_done;
476 	if (dma_dir != DMA_NONE &&
477 	    sas_protocol_ata(task->task_proto)) {
478 		task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
479 					       task->scatter,
480 					       task->num_scatter,
481 					       task->data_dir);
482 	}
483 
484 	for (retries = 0; retries < 5; retries++) {
485 		task->task_state_flags = SAS_TASK_STATE_PENDING;
486 		init_completion(&task->completion);
487 
488 		task->timer.data = (unsigned long) task;
489 		task->timer.function = sas_task_timedout;
490 		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
491 		add_timer(&task->timer);
492 
493 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
494 		if (res) {
495 			del_timer(&task->timer);
496 			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
497 				    res);
498 			goto ex_err;
499 		}
500 		wait_for_completion(&task->completion);
501 		res = -ECOMM;
502 		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
503 			int res2;
504 			SAS_DPRINTK("task aborted, flags:0x%x\n",
505 				    task->task_state_flags);
506 			res2 = i->dft->lldd_abort_task(task);
507 			SAS_DPRINTK("came back from abort task\n");
508 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
509 				if (res2 == TMF_RESP_FUNC_COMPLETE)
510 					continue; /* Retry the task */
511 				else
512 					goto ex_err;
513 			}
514 		}
515 		if (task->task_status.stat == SAM_BUSY ||
516 			   task->task_status.stat == SAM_TASK_SET_FULL ||
517 			   task->task_status.stat == SAS_QUEUE_FULL) {
518 			SAS_DPRINTK("task: q busy, sleeping...\n");
519 			schedule_timeout_interruptible(HZ);
520 		} else if (task->task_status.stat == SAM_CHECK_COND) {
521 			struct scsi_sense_hdr shdr;
522 
523 			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
524 						  &shdr)) {
525 				SAS_DPRINTK("couldn't normalize sense\n");
526 				continue;
527 			}
528 			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
529 			    (shdr.sense_key == 2 && shdr.asc == 4 &&
530 			     shdr.ascq == 1)) {
531 				SAS_DPRINTK("device %016llx LUN: %016llx "
532 					    "powering up or not ready yet, "
533 					    "sleeping...\n",
534 					    SAS_ADDR(task->dev->sas_addr),
535 					    SAS_ADDR(task->ssp_task.LUN));
536 
537 				schedule_timeout_interruptible(5*HZ);
538 			} else if (shdr.sense_key == 1) {
539 				res = 0;
540 				break;
541 			} else if (shdr.sense_key == 5) {
542 				break;
543 			} else {
544 				SAS_DPRINTK("dev %016llx LUN: %016llx "
545 					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
546 					    "\n",
547 					    SAS_ADDR(task->dev->sas_addr),
548 					    SAS_ADDR(task->ssp_task.LUN),
549 					    shdr.sense_key,
550 					    shdr.asc, shdr.ascq);
551 			}
552 		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
553 			   task->task_status.stat != SAM_GOOD) {
554 			SAS_DPRINTK("task finished with resp:0x%x, "
555 				    "stat:0x%x\n",
556 				    task->task_status.resp,
557 				    task->task_status.stat);
558 			goto ex_err;
559 		} else {
560 			res = 0;
561 			break;
562 		}
563 	}
564 ex_err:
565 	if (dma_dir != DMA_NONE) {
566 		if (sas_protocol_ata(task->task_proto))
567 			dma_unmap_sg(task->dev->port->ha->dev,
568 				     task->scatter, task->num_scatter,
569 				     task->data_dir);
570 		kfree(scatter);
571 	}
572 out:
573 	return res;
574 }
575 
576 /* ---------- SATA ---------- */
577 
578 static void sas_get_ata_command_set(struct domain_device *dev)
579 {
580 	struct dev_to_host_fis *fis =
581 		(struct dev_to_host_fis *) dev->frame_rcvd;
582 
583 	if ((fis->sector_count == 1 && /* ATA */
584 	     fis->lbal         == 1 &&
585 	     fis->lbam         == 0 &&
586 	     fis->lbah         == 0 &&
587 	     fis->device       == 0)
588 	    ||
589 	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
590 	     fis->lbal         == 0 &&
591 	     fis->lbam         == 0xCE &&
592 	     fis->lbah         == 0xAA &&
593 	     (fis->device & ~0x10) == 0))
594 
595 		dev->sata_dev.command_set = ATA_COMMAND_SET;
596 
597 	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
598 		  fis->lbal             == 1 &&
599 		  fis->byte_count_low   == 0x14 &&
600 		  fis->byte_count_high  == 0xEB &&
601 		  (fis->device & ~0x10) == 0))
602 
603 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
604 
605 	else if ((fis->sector_count == 1 && /* SEMB */
606 		  fis->lbal         == 1 &&
607 		  fis->lbam         == 0x3C &&
608 		  fis->lbah         == 0xC3 &&
609 		  fis->device       == 0)
610 		||
611 		 (fis->interrupt_reason == 1 &&	/* SATA PM */
612 		  fis->lbal             == 1 &&
613 		  fis->byte_count_low   == 0x69 &&
614 		  fis->byte_count_high  == 0x96 &&
615 		  (fis->device & ~0x10) == 0))
616 
617 		/* Treat it as a superset? */
618 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
619 }
620 
621 /**
622  * sas_issue_ata_cmd -- Basic SATA command processing for discovery
623  * @dev: the device to send the command to
624  * @command: the command register
625  * @features: the features register
626  * @buffer: pointer to buffer to do I/O
627  * @size: size of @buffer
628  * @dma_dir: DMA direction.  DMA_xxx
629  */
630 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
631 			     u8 features, void *buffer, int size,
632 			     enum dma_data_direction dma_dir)
633 {
634 	int res = 0;
635 	struct sas_task *task;
636 	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
637 		&dev->frame_rcvd[0];
638 
639 	res = -ENOMEM;
640 	task = sas_alloc_task(GFP_KERNEL);
641 	if (!task)
642 		goto out;
643 
644 	task->dev = dev;
645 
646 	task->ata_task.fis.fis_type = 0x27;
647 	task->ata_task.fis.command = command;
648 	task->ata_task.fis.features = features;
649 	task->ata_task.fis.device = d2h_fis->device;
650 	task->ata_task.retry_count = 1;
651 
652 	res = sas_execute_task(task, buffer, size, dma_dir);
653 
654 	sas_free_task(task);
655 out:
656 	return res;
657 }
658 
659 #define ATA_IDENTIFY_DEV         0xEC
660 #define ATA_IDENTIFY_PACKET_DEV  0xA1
661 #define ATA_SET_FEATURES         0xEF
662 #define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
663 
664 /**
665  * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
666  * @dev: STP/SATA device of interest (ATA/ATAPI)
667  *
668  * The LLDD has already been notified of this device, so that we can
669  * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
670  * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
671  * performance for this device.
672  */
673 static int sas_discover_sata_dev(struct domain_device *dev)
674 {
675 	int     res;
676 	__le16  *identify_x;
677 	u8      command;
678 
679 	identify_x = kzalloc(512, GFP_KERNEL);
680 	if (!identify_x)
681 		return -ENOMEM;
682 
683 	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
684 		dev->sata_dev.identify_device = identify_x;
685 		command = ATA_IDENTIFY_DEV;
686 	} else {
687 		dev->sata_dev.identify_packet_device = identify_x;
688 		command = ATA_IDENTIFY_PACKET_DEV;
689 	}
690 
691 	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
692 				DMA_FROM_DEVICE);
693 	if (res)
694 		goto out_err;
695 
696 	/* lives on the media? */
697 	if (le16_to_cpu(identify_x[0]) & 4) {
698 		/* incomplete response */
699 		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
700 			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
701 		if (!le16_to_cpu(identify_x[83] & (1<<6)))
702 			goto cont1;
703 		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
704 					ATA_FEATURE_PUP_STBY_SPIN_UP,
705 					NULL, 0, DMA_NONE);
706 		if (res)
707 			goto cont1;
708 
709 		schedule_timeout_interruptible(5*HZ); /* More time? */
710 		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
711 					DMA_FROM_DEVICE);
712 		if (res)
713 			goto out_err;
714 	}
715 cont1:
716 	/* XXX Hint: register this SATA device with SATL.
717 	   When this returns, dev->sata_dev->lu is alive and
718 	   present.
719 	sas_satl_register_dev(dev);
720 	*/
721 
722 	sas_fill_in_rphy(dev, dev->rphy);
723 
724 	return 0;
725 out_err:
726 	dev->sata_dev.identify_packet_device = NULL;
727 	dev->sata_dev.identify_device = NULL;
728 	kfree(identify_x);
729 	return res;
730 }
731 
732 static int sas_discover_sata_pm(struct domain_device *dev)
733 {
734 	return -ENODEV;
735 }
736 
737 /**
738  * sas_discover_sata -- discover an STP/SATA domain device
739  * @dev: pointer to struct domain_device of interest
740  *
741  * First we notify the LLDD of this device, so we can send frames to
742  * it.  Then depending on the type of device we call the appropriate
743  * discover functions.  Once device discover is done, we notify the
744  * LLDD so that it can fine-tune its parameters for the device, by
745  * removing it and then adding it.  That is, the second time around,
746  * the driver would have certain fields, that it is looking at, set.
747  * Finally we initialize the kobj so that the device can be added to
748  * the system at registration time.  Devices directly attached to a HA
749  * port, have no parents.  All other devices do, and should have their
750  * "parent" pointer set appropriately before calling this function.
751  */
752 int sas_discover_sata(struct domain_device *dev)
753 {
754 	int res;
755 
756 	sas_get_ata_command_set(dev);
757 
758 	res = sas_notify_lldd_dev_found(dev);
759 	if (res)
760 		return res;
761 
762 	switch (dev->dev_type) {
763 	case SATA_DEV:
764 		res = sas_discover_sata_dev(dev);
765 		break;
766 	case SATA_PM:
767 		res = sas_discover_sata_pm(dev);
768 		break;
769 	default:
770 		break;
771 	}
772 	sas_notify_lldd_dev_gone(dev);
773 	if (!res) {
774 		sas_notify_lldd_dev_found(dev);
775 		res = sas_rphy_add(dev->rphy);
776 	}
777 
778 	return res;
779 }
780