xref: /linux/drivers/scsi/libsas/sas_ata.c (revision 5a0e3ad6af8660be21ca98a971cd00f331318c05)
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_CHECK_COND:
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_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 	task = sas_alloc_task(GFP_ATOMIC);
166 	if (!task)
167 		return AC_ERR_SYSTEM;
168 	task->dev = dev;
169 	task->task_proto = SAS_PROTOCOL_STP;
170 	task->task_done = sas_ata_task_done;
171 
172 	if (qc->tf.command == ATA_CMD_FPDMA_WRITE ||
173 	    qc->tf.command == ATA_CMD_FPDMA_READ) {
174 		/* Need to zero out the tag libata assigned us */
175 		qc->tf.nsect = 0;
176 	}
177 
178 	ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
179 	task->uldd_task = qc;
180 	if (ata_is_atapi(qc->tf.protocol)) {
181 		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
182 		task->total_xfer_len = qc->nbytes;
183 		task->num_scatter = qc->n_elem;
184 	} else {
185 		for_each_sg(qc->sg, sg, qc->n_elem, si)
186 			xfer += sg->length;
187 
188 		task->total_xfer_len = xfer;
189 		task->num_scatter = si;
190 	}
191 
192 	task->data_dir = qc->dma_dir;
193 	task->scatter = qc->sg;
194 	task->ata_task.retry_count = 1;
195 	task->task_state_flags = SAS_TASK_STATE_PENDING;
196 	qc->lldd_task = task;
197 
198 	switch (qc->tf.protocol) {
199 	case ATA_PROT_NCQ:
200 		task->ata_task.use_ncq = 1;
201 		/* fall through */
202 	case ATAPI_PROT_DMA:
203 	case ATA_PROT_DMA:
204 		task->ata_task.dma_xfer = 1;
205 		break;
206 	}
207 
208 	if (qc->scsicmd)
209 		ASSIGN_SAS_TASK(qc->scsicmd, task);
210 
211 	if (sas_ha->lldd_max_execute_num < 2)
212 		res = i->dft->lldd_execute_task(task, 1, GFP_ATOMIC);
213 	else
214 		res = sas_queue_up(task);
215 
216 	/* Examine */
217 	if (res) {
218 		SAS_DPRINTK("lldd_execute_task returned: %d\n", res);
219 
220 		if (qc->scsicmd)
221 			ASSIGN_SAS_TASK(qc->scsicmd, NULL);
222 		sas_free_task(task);
223 		return AC_ERR_SYSTEM;
224 	}
225 
226 	return 0;
227 }
228 
229 static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc)
230 {
231 	struct domain_device *dev = qc->ap->private_data;
232 
233 	memcpy(&qc->result_tf, &dev->sata_dev.tf, sizeof(qc->result_tf));
234 	return true;
235 }
236 
237 static void sas_ata_phy_reset(struct ata_port *ap)
238 {
239 	struct domain_device *dev = ap->private_data;
240 	struct sas_internal *i =
241 		to_sas_internal(dev->port->ha->core.shost->transportt);
242 	int res = TMF_RESP_FUNC_FAILED;
243 
244 	if (i->dft->lldd_I_T_nexus_reset)
245 		res = i->dft->lldd_I_T_nexus_reset(dev);
246 
247 	if (res != TMF_RESP_FUNC_COMPLETE)
248 		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);
249 
250 	switch (dev->sata_dev.command_set) {
251 		case ATA_COMMAND_SET:
252 			SAS_DPRINTK("%s: Found ATA device.\n", __func__);
253 			ap->link.device[0].class = ATA_DEV_ATA;
254 			break;
255 		case ATAPI_COMMAND_SET:
256 			SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
257 			ap->link.device[0].class = ATA_DEV_ATAPI;
258 			break;
259 		default:
260 			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
261 				    __func__,
262 				    dev->sata_dev.command_set);
263 			ap->link.device[0].class = ATA_DEV_UNKNOWN;
264 			break;
265 	}
266 
267 	ap->cbl = ATA_CBL_SATA;
268 }
269 
270 static void sas_ata_post_internal(struct ata_queued_cmd *qc)
271 {
272 	if (qc->flags & ATA_QCFLAG_FAILED)
273 		qc->err_mask |= AC_ERR_OTHER;
274 
275 	if (qc->err_mask) {
276 		/*
277 		 * Find the sas_task and kill it.  By this point,
278 		 * libata has decided to kill the qc, so we needn't
279 		 * bother with sas_ata_task_done.  But we still
280 		 * ought to abort the task.
281 		 */
282 		struct sas_task *task = qc->lldd_task;
283 		unsigned long flags;
284 
285 		qc->lldd_task = NULL;
286 		if (task) {
287 			/* Should this be a AT(API) device reset? */
288 			spin_lock_irqsave(&task->task_state_lock, flags);
289 			task->task_state_flags |= SAS_TASK_NEED_DEV_RESET;
290 			spin_unlock_irqrestore(&task->task_state_lock, flags);
291 
292 			task->uldd_task = NULL;
293 			__sas_task_abort(task);
294 		}
295 	}
296 }
297 
298 static int sas_ata_scr_write(struct ata_link *link, unsigned int sc_reg_in,
299 			      u32 val)
300 {
301 	struct domain_device *dev = link->ap->private_data;
302 
303 	SAS_DPRINTK("STUB %s\n", __func__);
304 	switch (sc_reg_in) {
305 		case SCR_STATUS:
306 			dev->sata_dev.sstatus = val;
307 			break;
308 		case SCR_CONTROL:
309 			dev->sata_dev.scontrol = val;
310 			break;
311 		case SCR_ERROR:
312 			dev->sata_dev.serror = val;
313 			break;
314 		case SCR_ACTIVE:
315 			dev->sata_dev.ap->link.sactive = val;
316 			break;
317 		default:
318 			return -EINVAL;
319 	}
320 	return 0;
321 }
322 
323 static int sas_ata_scr_read(struct ata_link *link, unsigned int sc_reg_in,
324 			    u32 *val)
325 {
326 	struct domain_device *dev = link->ap->private_data;
327 
328 	SAS_DPRINTK("STUB %s\n", __func__);
329 	switch (sc_reg_in) {
330 		case SCR_STATUS:
331 			*val = dev->sata_dev.sstatus;
332 			return 0;
333 		case SCR_CONTROL:
334 			*val = dev->sata_dev.scontrol;
335 			return 0;
336 		case SCR_ERROR:
337 			*val = dev->sata_dev.serror;
338 			return 0;
339 		case SCR_ACTIVE:
340 			*val = dev->sata_dev.ap->link.sactive;
341 			return 0;
342 		default:
343 			return -EINVAL;
344 	}
345 }
346 
347 static struct ata_port_operations sas_sata_ops = {
348 	.phy_reset		= sas_ata_phy_reset,
349 	.post_internal_cmd	= sas_ata_post_internal,
350 	.qc_prep		= ata_noop_qc_prep,
351 	.qc_issue		= sas_ata_qc_issue,
352 	.qc_fill_rtf		= sas_ata_qc_fill_rtf,
353 	.port_start		= ata_sas_port_start,
354 	.port_stop		= ata_sas_port_stop,
355 	.scr_read		= sas_ata_scr_read,
356 	.scr_write		= sas_ata_scr_write
357 };
358 
359 static struct ata_port_info sata_port_info = {
360 	.flags = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY | ATA_FLAG_SATA_RESET |
361 		ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA | ATA_FLAG_NCQ,
362 	.pio_mask = 0x1f, /* PIO0-4 */
363 	.mwdma_mask = 0x07, /* MWDMA0-2 */
364 	.udma_mask = ATA_UDMA6,
365 	.port_ops = &sas_sata_ops
366 };
367 
368 int sas_ata_init_host_and_port(struct domain_device *found_dev,
369 			       struct scsi_target *starget)
370 {
371 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
372 	struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
373 	struct ata_port *ap;
374 
375 	ata_host_init(&found_dev->sata_dev.ata_host,
376 		      ha->dev,
377 		      sata_port_info.flags,
378 		      &sas_sata_ops);
379 	ap = ata_sas_port_alloc(&found_dev->sata_dev.ata_host,
380 				&sata_port_info,
381 				shost);
382 	if (!ap) {
383 		SAS_DPRINTK("ata_sas_port_alloc failed.\n");
384 		return -ENODEV;
385 	}
386 
387 	ap->private_data = found_dev;
388 	ap->cbl = ATA_CBL_SATA;
389 	ap->scsi_host = shost;
390 	found_dev->sata_dev.ap = ap;
391 
392 	return 0;
393 }
394 
395 void sas_ata_task_abort(struct sas_task *task)
396 {
397 	struct ata_queued_cmd *qc = task->uldd_task;
398 	struct completion *waiting;
399 
400 	/* Bounce SCSI-initiated commands to the SCSI EH */
401 	if (qc->scsicmd) {
402 		blk_abort_request(qc->scsicmd->request);
403 		scsi_schedule_eh(qc->scsicmd->device->host);
404 		return;
405 	}
406 
407 	/* Internal command, fake a timeout and complete. */
408 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
409 	qc->flags |= ATA_QCFLAG_FAILED;
410 	qc->err_mask |= AC_ERR_TIMEOUT;
411 	waiting = qc->private_data;
412 	complete(waiting);
413 }
414 
415 static void sas_task_timedout(unsigned long _task)
416 {
417 	struct sas_task *task = (void *) _task;
418 	unsigned long flags;
419 
420 	spin_lock_irqsave(&task->task_state_lock, flags);
421 	if (!(task->task_state_flags & SAS_TASK_STATE_DONE))
422 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
423 	spin_unlock_irqrestore(&task->task_state_lock, flags);
424 
425 	complete(&task->completion);
426 }
427 
428 static void sas_disc_task_done(struct sas_task *task)
429 {
430 	if (!del_timer(&task->timer))
431 		return;
432 	complete(&task->completion);
433 }
434 
435 #define SAS_DEV_TIMEOUT 10
436 
437 /**
438  * sas_execute_task -- Basic task processing for discovery
439  * @task: the task to be executed
440  * @buffer: pointer to buffer to do I/O
441  * @size: size of @buffer
442  * @dma_dir: DMA direction.  DMA_xxx
443  */
444 static int sas_execute_task(struct sas_task *task, void *buffer, int size,
445 			    enum dma_data_direction dma_dir)
446 {
447 	int res = 0;
448 	struct scatterlist *scatter = NULL;
449 	struct task_status_struct *ts = &task->task_status;
450 	int num_scatter = 0;
451 	int retries = 0;
452 	struct sas_internal *i =
453 		to_sas_internal(task->dev->port->ha->core.shost->transportt);
454 
455 	if (dma_dir != DMA_NONE) {
456 		scatter = kzalloc(sizeof(*scatter), GFP_KERNEL);
457 		if (!scatter)
458 			goto out;
459 
460 		sg_init_one(scatter, buffer, size);
461 		num_scatter = 1;
462 	}
463 
464 	task->task_proto = task->dev->tproto;
465 	task->scatter = scatter;
466 	task->num_scatter = num_scatter;
467 	task->total_xfer_len = size;
468 	task->data_dir = dma_dir;
469 	task->task_done = sas_disc_task_done;
470 	if (dma_dir != DMA_NONE &&
471 	    sas_protocol_ata(task->task_proto)) {
472 		task->num_scatter = dma_map_sg(task->dev->port->ha->dev,
473 					       task->scatter,
474 					       task->num_scatter,
475 					       task->data_dir);
476 	}
477 
478 	for (retries = 0; retries < 5; retries++) {
479 		task->task_state_flags = SAS_TASK_STATE_PENDING;
480 		init_completion(&task->completion);
481 
482 		task->timer.data = (unsigned long) task;
483 		task->timer.function = sas_task_timedout;
484 		task->timer.expires = jiffies + SAS_DEV_TIMEOUT*HZ;
485 		add_timer(&task->timer);
486 
487 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
488 		if (res) {
489 			del_timer(&task->timer);
490 			SAS_DPRINTK("executing SAS discovery task failed:%d\n",
491 				    res);
492 			goto ex_err;
493 		}
494 		wait_for_completion(&task->completion);
495 		res = -ECOMM;
496 		if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
497 			int res2;
498 			SAS_DPRINTK("task aborted, flags:0x%x\n",
499 				    task->task_state_flags);
500 			res2 = i->dft->lldd_abort_task(task);
501 			SAS_DPRINTK("came back from abort task\n");
502 			if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
503 				if (res2 == TMF_RESP_FUNC_COMPLETE)
504 					continue; /* Retry the task */
505 				else
506 					goto ex_err;
507 			}
508 		}
509 		if (task->task_status.stat == SAM_BUSY ||
510 			   task->task_status.stat == SAM_TASK_SET_FULL ||
511 			   task->task_status.stat == SAS_QUEUE_FULL) {
512 			SAS_DPRINTK("task: q busy, sleeping...\n");
513 			schedule_timeout_interruptible(HZ);
514 		} else if (task->task_status.stat == SAM_CHECK_COND) {
515 			struct scsi_sense_hdr shdr;
516 
517 			if (!scsi_normalize_sense(ts->buf, ts->buf_valid_size,
518 						  &shdr)) {
519 				SAS_DPRINTK("couldn't normalize sense\n");
520 				continue;
521 			}
522 			if ((shdr.sense_key == 6 && shdr.asc == 0x29) ||
523 			    (shdr.sense_key == 2 && shdr.asc == 4 &&
524 			     shdr.ascq == 1)) {
525 				SAS_DPRINTK("device %016llx LUN: %016llx "
526 					    "powering up or not ready yet, "
527 					    "sleeping...\n",
528 					    SAS_ADDR(task->dev->sas_addr),
529 					    SAS_ADDR(task->ssp_task.LUN));
530 
531 				schedule_timeout_interruptible(5*HZ);
532 			} else if (shdr.sense_key == 1) {
533 				res = 0;
534 				break;
535 			} else if (shdr.sense_key == 5) {
536 				break;
537 			} else {
538 				SAS_DPRINTK("dev %016llx LUN: %016llx "
539 					    "sense key:0x%x ASC:0x%x ASCQ:0x%x"
540 					    "\n",
541 					    SAS_ADDR(task->dev->sas_addr),
542 					    SAS_ADDR(task->ssp_task.LUN),
543 					    shdr.sense_key,
544 					    shdr.asc, shdr.ascq);
545 			}
546 		} else if (task->task_status.resp != SAS_TASK_COMPLETE ||
547 			   task->task_status.stat != SAM_GOOD) {
548 			SAS_DPRINTK("task finished with resp:0x%x, "
549 				    "stat:0x%x\n",
550 				    task->task_status.resp,
551 				    task->task_status.stat);
552 			goto ex_err;
553 		} else {
554 			res = 0;
555 			break;
556 		}
557 	}
558 ex_err:
559 	if (dma_dir != DMA_NONE) {
560 		if (sas_protocol_ata(task->task_proto))
561 			dma_unmap_sg(task->dev->port->ha->dev,
562 				     task->scatter, task->num_scatter,
563 				     task->data_dir);
564 		kfree(scatter);
565 	}
566 out:
567 	return res;
568 }
569 
570 /* ---------- SATA ---------- */
571 
572 static void sas_get_ata_command_set(struct domain_device *dev)
573 {
574 	struct dev_to_host_fis *fis =
575 		(struct dev_to_host_fis *) dev->frame_rcvd;
576 
577 	if ((fis->sector_count == 1 && /* ATA */
578 	     fis->lbal         == 1 &&
579 	     fis->lbam         == 0 &&
580 	     fis->lbah         == 0 &&
581 	     fis->device       == 0)
582 	    ||
583 	    (fis->sector_count == 0 && /* CE-ATA (mATA) */
584 	     fis->lbal         == 0 &&
585 	     fis->lbam         == 0xCE &&
586 	     fis->lbah         == 0xAA &&
587 	     (fis->device & ~0x10) == 0))
588 
589 		dev->sata_dev.command_set = ATA_COMMAND_SET;
590 
591 	else if ((fis->interrupt_reason == 1 &&	/* ATAPI */
592 		  fis->lbal             == 1 &&
593 		  fis->byte_count_low   == 0x14 &&
594 		  fis->byte_count_high  == 0xEB &&
595 		  (fis->device & ~0x10) == 0))
596 
597 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
598 
599 	else if ((fis->sector_count == 1 && /* SEMB */
600 		  fis->lbal         == 1 &&
601 		  fis->lbam         == 0x3C &&
602 		  fis->lbah         == 0xC3 &&
603 		  fis->device       == 0)
604 		||
605 		 (fis->interrupt_reason == 1 &&	/* SATA PM */
606 		  fis->lbal             == 1 &&
607 		  fis->byte_count_low   == 0x69 &&
608 		  fis->byte_count_high  == 0x96 &&
609 		  (fis->device & ~0x10) == 0))
610 
611 		/* Treat it as a superset? */
612 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
613 }
614 
615 /**
616  * sas_issue_ata_cmd -- Basic SATA command processing for discovery
617  * @dev: the device to send the command to
618  * @command: the command register
619  * @features: the features register
620  * @buffer: pointer to buffer to do I/O
621  * @size: size of @buffer
622  * @dma_dir: DMA direction.  DMA_xxx
623  */
624 static int sas_issue_ata_cmd(struct domain_device *dev, u8 command,
625 			     u8 features, void *buffer, int size,
626 			     enum dma_data_direction dma_dir)
627 {
628 	int res = 0;
629 	struct sas_task *task;
630 	struct dev_to_host_fis *d2h_fis = (struct dev_to_host_fis *)
631 		&dev->frame_rcvd[0];
632 
633 	res = -ENOMEM;
634 	task = sas_alloc_task(GFP_KERNEL);
635 	if (!task)
636 		goto out;
637 
638 	task->dev = dev;
639 
640 	task->ata_task.fis.fis_type = 0x27;
641 	task->ata_task.fis.command = command;
642 	task->ata_task.fis.features = features;
643 	task->ata_task.fis.device = d2h_fis->device;
644 	task->ata_task.retry_count = 1;
645 
646 	res = sas_execute_task(task, buffer, size, dma_dir);
647 
648 	sas_free_task(task);
649 out:
650 	return res;
651 }
652 
653 #define ATA_IDENTIFY_DEV         0xEC
654 #define ATA_IDENTIFY_PACKET_DEV  0xA1
655 #define ATA_SET_FEATURES         0xEF
656 #define ATA_FEATURE_PUP_STBY_SPIN_UP 0x07
657 
658 /**
659  * sas_discover_sata_dev -- discover a STP/SATA device (SATA_DEV)
660  * @dev: STP/SATA device of interest (ATA/ATAPI)
661  *
662  * The LLDD has already been notified of this device, so that we can
663  * send FISes to it.  Here we try to get IDENTIFY DEVICE or IDENTIFY
664  * PACKET DEVICE, if ATAPI device, so that the LLDD can fine-tune its
665  * performance for this device.
666  */
667 static int sas_discover_sata_dev(struct domain_device *dev)
668 {
669 	int     res;
670 	__le16  *identify_x;
671 	u8      command;
672 
673 	identify_x = kzalloc(512, GFP_KERNEL);
674 	if (!identify_x)
675 		return -ENOMEM;
676 
677 	if (dev->sata_dev.command_set == ATA_COMMAND_SET) {
678 		dev->sata_dev.identify_device = identify_x;
679 		command = ATA_IDENTIFY_DEV;
680 	} else {
681 		dev->sata_dev.identify_packet_device = identify_x;
682 		command = ATA_IDENTIFY_PACKET_DEV;
683 	}
684 
685 	res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
686 				DMA_FROM_DEVICE);
687 	if (res)
688 		goto out_err;
689 
690 	/* lives on the media? */
691 	if (le16_to_cpu(identify_x[0]) & 4) {
692 		/* incomplete response */
693 		SAS_DPRINTK("sending SET FEATURE/PUP_STBY_SPIN_UP to "
694 			    "dev %llx\n", SAS_ADDR(dev->sas_addr));
695 		if (!(identify_x[83] & cpu_to_le16(1<<6)))
696 			goto cont1;
697 		res = sas_issue_ata_cmd(dev, ATA_SET_FEATURES,
698 					ATA_FEATURE_PUP_STBY_SPIN_UP,
699 					NULL, 0, DMA_NONE);
700 		if (res)
701 			goto cont1;
702 
703 		schedule_timeout_interruptible(5*HZ); /* More time? */
704 		res = sas_issue_ata_cmd(dev, command, 0, identify_x, 512,
705 					DMA_FROM_DEVICE);
706 		if (res)
707 			goto out_err;
708 	}
709 cont1:
710 	/* XXX Hint: register this SATA device with SATL.
711 	   When this returns, dev->sata_dev->lu is alive and
712 	   present.
713 	sas_satl_register_dev(dev);
714 	*/
715 
716 	sas_fill_in_rphy(dev, dev->rphy);
717 
718 	return 0;
719 out_err:
720 	dev->sata_dev.identify_packet_device = NULL;
721 	dev->sata_dev.identify_device = NULL;
722 	kfree(identify_x);
723 	return res;
724 }
725 
726 static int sas_discover_sata_pm(struct domain_device *dev)
727 {
728 	return -ENODEV;
729 }
730 
731 /**
732  * sas_discover_sata -- discover an STP/SATA domain device
733  * @dev: pointer to struct domain_device of interest
734  *
735  * First we notify the LLDD of this device, so we can send frames to
736  * it.  Then depending on the type of device we call the appropriate
737  * discover functions.  Once device discover is done, we notify the
738  * LLDD so that it can fine-tune its parameters for the device, by
739  * removing it and then adding it.  That is, the second time around,
740  * the driver would have certain fields, that it is looking at, set.
741  * Finally we initialize the kobj so that the device can be added to
742  * the system at registration time.  Devices directly attached to a HA
743  * port, have no parents.  All other devices do, and should have their
744  * "parent" pointer set appropriately before calling this function.
745  */
746 int sas_discover_sata(struct domain_device *dev)
747 {
748 	int res;
749 
750 	sas_get_ata_command_set(dev);
751 
752 	res = sas_notify_lldd_dev_found(dev);
753 	if (res)
754 		return res;
755 
756 	switch (dev->dev_type) {
757 	case SATA_DEV:
758 		res = sas_discover_sata_dev(dev);
759 		break;
760 	case SATA_PM:
761 		res = sas_discover_sata_pm(dev);
762 		break;
763 	default:
764 		break;
765 	}
766 	sas_notify_lldd_dev_gone(dev);
767 	if (!res) {
768 		sas_notify_lldd_dev_found(dev);
769 		res = sas_rphy_add(dev->rphy);
770 	}
771 
772 	return res;
773 }
774