xref: /openbmc/linux/drivers/scsi/libsas/sas_ata.c (revision ecba1060)
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 				    __func__, 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", __func__,
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 bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
229 {
230 	struct domain_device *dev = qc->ap->private_data;
231 
232 	memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
233 	return true;
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 = TMF_RESP_FUNC_FAILED;
242 
243 	if (i->dft->lldd_I_T_nexus_reset)
244 		res = i->dft->lldd_I_T_nexus_reset(dev);
245 
246 	if (res != TMF_RESP_FUNC_COMPLETE)
247 		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);
248 
249 	switch (dev->sata_dev.command_set) {
250 		case ATA_COMMAND_SET:
251 			SAS_DPRINTK("%s: Found ATA device.\n", __func__);
252 			ap->link.device[0].class = ATA_DEV_ATA;
253 			break;
254 		case ATAPI_COMMAND_SET:
255 			SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
256 			ap->link.device[0].class = ATA_DEV_ATAPI;
257 			break;
258 		default:
259 			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
260 				    __func__,
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 int sas_ata_scr_write(struct ata_link *link, unsigned int sc_reg_in,
298 			      u32 val)
299 {
300 	struct domain_device *dev = link->ap->private_data;
301 
302 	SAS_DPRINTK("STUB %s\n", __func__);
303 	switch (sc_reg_in) {
304 		case SCR_STATUS:
305 			dev->sata_dev.sstatus = val;
306 			break;
307 		case SCR_CONTROL:
308 			dev->sata_dev.scontrol = val;
309 			break;
310 		case SCR_ERROR:
311 			dev->sata_dev.serror = val;
312 			break;
313 		case SCR_ACTIVE:
314 			dev->sata_dev.ap->link.sactive = val;
315 			break;
316 		default:
317 			return -EINVAL;
318 	}
319 	return 0;
320 }
321 
322 static int sas_ata_scr_read(struct ata_link *link, unsigned int sc_reg_in,
323 			    u32 *val)
324 {
325 	struct domain_device *dev = link->ap->private_data;
326 
327 	SAS_DPRINTK("STUB %s\n", __func__);
328 	switch (sc_reg_in) {
329 		case SCR_STATUS:
330 			*val = dev->sata_dev.sstatus;
331 			return 0;
332 		case SCR_CONTROL:
333 			*val = dev->sata_dev.scontrol;
334 			return 0;
335 		case SCR_ERROR:
336 			*val = dev->sata_dev.serror;
337 			return 0;
338 		case SCR_ACTIVE:
339 			*val = dev->sata_dev.ap->link.sactive;
340 			return 0;
341 		default:
342 			return -EINVAL;
343 	}
344 }
345 
346 static struct ata_port_operations sas_sata_ops = {
347 	.phy_reset		= sas_ata_phy_reset,
348 	.post_internal_cmd	= sas_ata_post_internal,
349 	.qc_prep		= ata_noop_qc_prep,
350 	.qc_issue		= sas_ata_qc_issue,
351 	.qc_fill_rtf		= sas_ata_qc_fill_rtf,
352 	.port_start		= ata_sas_port_start,
353 	.port_stop		= ata_sas_port_stop,
354 	.scr_read		= sas_ata_scr_read,
355 	.scr_write		= sas_ata_scr_write
356 };
357 
358 static struct ata_port_info sata_port_info = {
359 	.flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY | ATA_FLAG_SATA_RESET |
360 		ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
361 	.pio_mask = 0x1f, /* PIO0-4 */
362 	.mwdma_mask = 0x07, /* MWDMA0-2 */
363 	.udma_mask = ATA_UDMA6,
364 	.port_ops = &sas_sata_ops
365 };
366 
367 int sas_ata_init_host_and_port(struct domain_device *found_dev,
368 			       struct scsi_target *starget)
369 {
370 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
371 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
372 	struct ata_port *ap;
373 
374 	ata_host_init(&found_dev->sata_dev.ata_host,
375 		      ha->dev,
376 		      sata_port_info.flags,
377 		      &sas_sata_ops);
378 	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
379 				&sata_port_info,
380 				shost);
381 	if (!ap) {
382 		SAS_DPRINTK("ata_sas_port_alloc failed.\n");
383 		return -ENODEV;
384 	}
385 
386 	ap->private_data = found_dev;
387 	ap->cbl = ATA_CBL_SATA;
388 	ap->scsi_host = shost;
389 	found_dev->sata_dev.ap = ap;
390 
391 	return 0;
392 }
393 
394 void sas_ata_task_abort(struct sas_task *task)
395 {
396 	struct ata_queued_cmd *qc = task->uldd_task;
397 	struct completion *waiting;
398 
399 	/* Bounce SCSI-initiated commands to the SCSI EH */
400 	if (qc->scsicmd) {
401 		blk_abort_request(qc->scsicmd->request);
402 		scsi_schedule_eh(qc->scsicmd->device->host);
403 		return;
404 	}
405 
406 	/* Internal command, fake a timeout and complete. */
407 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
408 	qc->flags |= ATA_QCFLAG_FAILED;
409 	qc->err_mask |= AC_ERR_TIMEOUT;
410 	waiting = qc->private_data;
411 	complete(waiting);
412 }
413 
414 static void sas_task_timedout(unsigned long _task)
415 {
416 	struct sas_task *task = (void *) _task;
417 	unsigned long flags;
418 
419 	spin_lock_irqsave(&task->task_state_lock, flags);
420 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
421 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
422 	spin_unlock_irqrestore(&task->task_state_lock, flags);
423 
424 	complete(&task->completion);
425 }
426 
427 static void sas_disc_task_done(struct sas_task *task)
428 {
429 	if (!del_timer(&task->timer))
430 		return;
431 	complete(&task->completion);
432 }
433 
434 #define SAS_DEV_TIMEOUT 10
435 
436 /**
437  * sas_execute_task -- Basic task processing for discovery
438  * @task: the task to be executed
439  * @buffer: pointer to buffer to do I/O
440  * @size: size of @buffer
441  * @dma_dir: DMA direction.  DMA_xxx
442  */
443 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
444 			    enum dma_data_direction dma_dir)
445 {
446 	int res = 0;
447 	struct scatterlist *scatter = NULL;
448 	struct task_status_struct *ts = &task->task_status;
449 	int num_scatter = 0;
450 	int retries = 0;
451 	struct sas_internal *i =
452 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
453 
454 	if (dma_dir != DMA_NONE) {
455 		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
456 		if (!scatter)
457 			goto out;
458 
459 		sg_init_one(scatter, buffer, size);
460 		num_scatter = 1;
461 	}
462 
463 	task->task_proto = task->dev->tproto;
464 	task->scatter = scatter;
465 	task->num_scatter = num_scatter;
466 	task->total_xfer_len = size;
467 	task->data_dir = dma_dir;
468 	task->task_done = sas_disc_task_done;
469 	if (dma_dir != DMA_NONE &&
470 	    sas_protocol_ata(task->task_proto)) {
471 		task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
472 					       task->scatter,
473 					       task->num_scatter,
474 					       task->data_dir);
475 	}
476 
477 	for (retries = 0; retries < 5; retries++) {
478 		task->task_state_flags = SAS_TASK_STATE_PENDING;
479 		init_completion(&task->completion);
480 
481 		task->timer.data = (unsigned long) task;
482 		task->timer.function = sas_task_timedout;
483 		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
484 		add_timer(&task->timer);
485 
486 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
487 		if (res) {
488 			del_timer(&task->timer);
489 			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
490 				    res);
491 			goto ex_err;
492 		}
493 		wait_for_completion(&task->completion);
494 		res = -ECOMM;
495 		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
496 			int res2;
497 			SAS_DPRINTK("task aborted, flags:0x%x\n",
498 				    task->task_state_flags);
499 			res2 = i->dft->lldd_abort_task(task);
500 			SAS_DPRINTK("came back from abort task\n");
501 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
502 				if (res2 == TMF_RESP_FUNC_COMPLETE)
503 					continue; /* Retry the task */
504 				else
505 					goto ex_err;
506 			}
507 		}
508 		if (task->task_status.stat == SAM_BUSY ||
509 			   task->task_status.stat == SAM_TASK_SET_FULL ||
510 			   task->task_status.stat == SAS_QUEUE_FULL) {
511 			SAS_DPRINTK("task: q busy, sleeping...\n");
512 			schedule_timeout_interruptible(HZ);
513 		} else if (task->task_status.stat == SAM_CHECK_COND) {
514 			struct scsi_sense_hdr shdr;
515 
516 			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
517 						  &shdr)) {
518 				SAS_DPRINTK("couldn't normalize sense\n");
519 				continue;
520 			}
521 			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
522 			    (shdr.sense_key == 2 && shdr.asc == 4 &&
523 			     shdr.ascq == 1)) {
524 				SAS_DPRINTK("device %016llx LUN: %016llx "
525 					    "powering up or not ready yet, "
526 					    "sleeping...\n",
527 					    SAS_ADDR(task->dev->sas_addr),
528 					    SAS_ADDR(task->ssp_task.LUN));
529 
530 				schedule_timeout_interruptible(5*HZ);
531 			} else if (shdr.sense_key == 1) {
532 				res = 0;
533 				break;
534 			} else if (shdr.sense_key == 5) {
535 				break;
536 			} else {
537 				SAS_DPRINTK("dev %016llx LUN: %016llx "
538 					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
539 					    "\n",
540 					    SAS_ADDR(task->dev->sas_addr),
541 					    SAS_ADDR(task->ssp_task.LUN),
542 					    shdr.sense_key,
543 					    shdr.asc, shdr.ascq);
544 			}
545 		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
546 			   task->task_status.stat != SAM_GOOD) {
547 			SAS_DPRINTK("task finished with resp:0x%x, "
548 				    "stat:0x%x\n",
549 				    task->task_status.resp,
550 				    task->task_status.stat);
551 			goto ex_err;
552 		} else {
553 			res = 0;
554 			break;
555 		}
556 	}
557 ex_err:
558 	if (dma_dir != DMA_NONE) {
559 		if (sas_protocol_ata(task->task_proto))
560 			dma_unmap_sg(task->dev->port->ha->dev,
561 				     task->scatter, task->num_scatter,
562 				     task->data_dir);
563 		kfree(scatter);
564 	}
565 out:
566 	return res;
567 }
568 
569 /* ---------- SATA ---------- */
570 
571 static void sas_get_ata_command_set(struct domain_device *dev)
572 {
573 	struct dev_to_host_fis *fis =
574 		(struct dev_to_host_fis *) dev->frame_rcvd;
575 
576 	if ((fis->sector_count == 1 && /* ATA */
577 	     fis->lbal         == 1 &&
578 	     fis->lbam         == 0 &&
579 	     fis->lbah         == 0 &&
580 	     fis->device       == 0)
581 	    ||
582 	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
583 	     fis->lbal         == 0 &&
584 	     fis->lbam         == 0xCE &&
585 	     fis->lbah         == 0xAA &&
586 	     (fis->device & ~0x10) == 0))
587 
588 		dev->sata_dev.command_set = ATA_COMMAND_SET;
589 
590 	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
591 		  fis->lbal             == 1 &&
592 		  fis->byte_count_low   == 0x14 &&
593 		  fis->byte_count_high  == 0xEB &&
594 		  (fis->device & ~0x10) == 0))
595 
596 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
597 
598 	else if ((fis->sector_count == 1 && /* SEMB */
599 		  fis->lbal         == 1 &&
600 		  fis->lbam         == 0x3C &&
601 		  fis->lbah         == 0xC3 &&
602 		  fis->device       == 0)
603 		||
604 		 (fis->interrupt_reason == 1 &&	/* SATA PM */
605 		  fis->lbal             == 1 &&
606 		  fis->byte_count_low   == 0x69 &&
607 		  fis->byte_count_high  == 0x96 &&
608 		  (fis->device & ~0x10) == 0))
609 
610 		/* Treat it as a superset? */
611 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
612 }
613 
614 /**
615  * sas_issue_ata_cmd -- Basic SATA command processing for discovery
616  * @dev: the device to send the command to
617  * @command: the command register
618  * @features: the features register
619  * @buffer: pointer to buffer to do I/O
620  * @size: size of @buffer
621  * @dma_dir: DMA direction.  DMA_xxx
622  */
623 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
624 			     u8 features, void *buffer, int size,
625 			     enum dma_data_direction dma_dir)
626 {
627 	int res = 0;
628 	struct sas_task *task;
629 	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
630 		&dev->frame_rcvd[0];
631 
632 	res = -ENOMEM;
633 	task = sas_alloc_task(GFP_KERNEL);
634 	if (!task)
635 		goto out;
636 
637 	task->dev = dev;
638 
639 	task->ata_task.fis.fis_type = 0x27;
640 	task->ata_task.fis.command = command;
641 	task->ata_task.fis.features = features;
642 	task->ata_task.fis.device = d2h_fis->device;
643 	task->ata_task.retry_count = 1;
644 
645 	res = sas_execute_task(task, buffer, size, dma_dir);
646 
647 	sas_free_task(task);
648 out:
649 	return res;
650 }
651 
652 #define ATA_IDENTIFY_DEV         0xEC
653 #define ATA_IDENTIFY_PACKET_DEV  0xA1
654 #define ATA_SET_FEATURES         0xEF
655 #define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
656 
657 /**
658  * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
659  * @dev: STP/SATA device of interest (ATA/ATAPI)
660  *
661  * The LLDD has already been notified of this device, so that we can
662  * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
663  * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
664  * performance for this device.
665  */
666 static int sas_discover_sata_dev(struct domain_device *dev)
667 {
668 	int     res;
669 	__le16  *identify_x;
670 	u8      command;
671 
672 	identify_x = kzalloc(512, GFP_KERNEL);
673 	if (!identify_x)
674 		return -ENOMEM;
675 
676 	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
677 		dev->sata_dev.identify_device = identify_x;
678 		command = ATA_IDENTIFY_DEV;
679 	} else {
680 		dev->sata_dev.identify_packet_device = identify_x;
681 		command = ATA_IDENTIFY_PACKET_DEV;
682 	}
683 
684 	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
685 				DMA_FROM_DEVICE);
686 	if (res)
687 		goto out_err;
688 
689 	/* lives on the media? */
690 	if (le16_to_cpu(identify_x[0]) & 4) {
691 		/* incomplete response */
692 		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
693 			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
694 		if (!(identify_x[83] & cpu_to_le16(1<<6)))
695 			goto cont1;
696 		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
697 					ATA_FEATURE_PUP_STBY_SPIN_UP,
698 					NULL, 0, DMA_NONE);
699 		if (res)
700 			goto cont1;
701 
702 		schedule_timeout_interruptible(5*HZ); /* More time? */
703 		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
704 					DMA_FROM_DEVICE);
705 		if (res)
706 			goto out_err;
707 	}
708 cont1:
709 	/* XXX Hint: register this SATA device with SATL.
710 	   When this returns, dev->sata_dev->lu is alive and
711 	   present.
712 	sas_satl_register_dev(dev);
713 	*/
714 
715 	sas_fill_in_rphy(dev, dev->rphy);
716 
717 	return 0;
718 out_err:
719 	dev->sata_dev.identify_packet_device = NULL;
720 	dev->sata_dev.identify_device = NULL;
721 	kfree(identify_x);
722 	return res;
723 }
724 
725 static int sas_discover_sata_pm(struct domain_device *dev)
726 {
727 	return -ENODEV;
728 }
729 
730 /**
731  * sas_discover_sata -- discover an STP/SATA domain device
732  * @dev: pointer to struct domain_device of interest
733  *
734  * First we notify the LLDD of this device, so we can send frames to
735  * it.  Then depending on the type of device we call the appropriate
736  * discover functions.  Once device discover is done, we notify the
737  * LLDD so that it can fine-tune its parameters for the device, by
738  * removing it and then adding it.  That is, the second time around,
739  * the driver would have certain fields, that it is looking at, set.
740  * Finally we initialize the kobj so that the device can be added to
741  * the system at registration time.  Devices directly attached to a HA
742  * port, have no parents.  All other devices do, and should have their
743  * "parent" pointer set appropriately before calling this function.
744  */
745 int sas_discover_sata(struct domain_device *dev)
746 {
747 	int res;
748 
749 	sas_get_ata_command_set(dev);
750 
751 	res = sas_notify_lldd_dev_found(dev);
752 	if (res)
753 		return res;
754 
755 	switch (dev->dev_type) {
756 	case SATA_DEV:
757 		res = sas_discover_sata_dev(dev);
758 		break;
759 	case SATA_PM:
760 		res = sas_discover_sata_pm(dev);
761 		break;
762 	default:
763 		break;
764 	}
765 	sas_notify_lldd_dev_gone(dev);
766 	if (!res) {
767 		sas_notify_lldd_dev_found(dev);
768 		res = sas_rphy_add(dev->rphy);
769 	}
770 
771 	return res;
772 }
773