1 /*
2  *  Copyright 2008 ioogle, Inc.  All rights reserved.
3  *	Released under GPL v2.
4  *
5  * Libata transport class.
6  *
7  * The ATA transport class contains common code to deal with ATA HBAs,
8  * an approximated representation of ATA topologies in the driver model,
9  * and various sysfs attributes to expose these topologies and management
10  * interfaces to user-space.
11  *
12  * There are 3 objects defined in in this class:
13  * - ata_port
14  * - ata_link
15  * - ata_device
16  * Each port has a link object. Each link can have up to two devices for PATA
17  * and generally one for SATA.
18  * If there is SATA port multiplier [PMP], 15 additional ata_link object are
19  * created.
20  *
21  * These objects are created when the ata host is initialized and when a PMP is
22  * found. They are removed only when the HBA is removed, cleaned before the
23  * error handler runs.
24  */
25 
26 
27 #include <linux/kernel.h>
28 #include <linux/blkdev.h>
29 #include <linux/spinlock.h>
30 #include <linux/slab.h>
31 #include <scsi/scsi_transport.h>
32 #include <linux/libata.h>
33 #include <linux/hdreg.h>
34 #include <linux/uaccess.h>
35 #include <linux/pm_runtime.h>
36 
37 #include "libata.h"
38 #include "libata-transport.h"
39 
40 #define ATA_PORT_ATTRS		3
41 #define ATA_LINK_ATTRS		3
42 #define ATA_DEV_ATTRS		9
43 
44 struct scsi_transport_template;
45 struct scsi_transport_template *ata_scsi_transport_template;
46 
47 struct ata_internal {
48 	struct scsi_transport_template t;
49 
50 	struct device_attribute private_port_attrs[ATA_PORT_ATTRS];
51 	struct device_attribute private_link_attrs[ATA_LINK_ATTRS];
52 	struct device_attribute private_dev_attrs[ATA_DEV_ATTRS];
53 
54 	struct transport_container link_attr_cont;
55 	struct transport_container dev_attr_cont;
56 
57 	/*
58 	 * The array of null terminated pointers to attributes
59 	 * needed by scsi_sysfs.c
60 	 */
61 	struct device_attribute *link_attrs[ATA_LINK_ATTRS + 1];
62 	struct device_attribute *port_attrs[ATA_PORT_ATTRS + 1];
63 	struct device_attribute *dev_attrs[ATA_DEV_ATTRS + 1];
64 };
65 #define to_ata_internal(tmpl)	container_of(tmpl, struct ata_internal, t)
66 
67 
68 #define tdev_to_device(d)					\
69 	container_of((d), struct ata_device, tdev)
70 #define transport_class_to_dev(dev)				\
71 	tdev_to_device((dev)->parent)
72 
73 #define tdev_to_link(d)						\
74 	container_of((d), struct ata_link, tdev)
75 #define transport_class_to_link(dev)				\
76 	tdev_to_link((dev)->parent)
77 
78 #define tdev_to_port(d)						\
79 	container_of((d), struct ata_port, tdev)
80 #define transport_class_to_port(dev)				\
81 	tdev_to_port((dev)->parent)
82 
83 
84 /* Device objects are always created whit link objects */
85 static int ata_tdev_add(struct ata_device *dev);
86 static void ata_tdev_delete(struct ata_device *dev);
87 
88 
89 /*
90  * Hack to allow attributes of the same name in different objects.
91  */
92 #define ATA_DEVICE_ATTR(_prefix,_name,_mode,_show,_store) \
93 	struct device_attribute device_attr_##_prefix##_##_name = \
94 	__ATTR(_name,_mode,_show,_store)
95 
96 #define ata_bitfield_name_match(title, table)			\
97 static ssize_t							\
98 get_ata_##title##_names(u32 table_key, char *buf)		\
99 {								\
100 	char *prefix = "";					\
101 	ssize_t len = 0;					\
102 	int i;							\
103 								\
104 	for (i = 0; i < ARRAY_SIZE(table); i++) {		\
105 		if (table[i].value & table_key) {		\
106 			len += sprintf(buf + len, "%s%s",	\
107 				prefix, table[i].name);		\
108 			prefix = ", ";				\
109 		}						\
110 	}							\
111 	len += sprintf(buf + len, "\n");			\
112 	return len;						\
113 }
114 
115 #define ata_bitfield_name_search(title, table)			\
116 static ssize_t							\
117 get_ata_##title##_names(u32 table_key, char *buf)		\
118 {								\
119 	ssize_t len = 0;					\
120 	int i;							\
121 								\
122 	for (i = 0; i < ARRAY_SIZE(table); i++) {		\
123 		if (table[i].value == table_key) {		\
124 			len += sprintf(buf + len, "%s",		\
125 				table[i].name);			\
126 			break;					\
127 		}						\
128 	}							\
129 	len += sprintf(buf + len, "\n");			\
130 	return len;						\
131 }
132 
133 static struct {
134 	u32		value;
135 	char		*name;
136 } ata_class_names[] = {
137 	{ ATA_DEV_UNKNOWN,		"unknown" },
138 	{ ATA_DEV_ATA,			"ata" },
139 	{ ATA_DEV_ATA_UNSUP,		"ata" },
140 	{ ATA_DEV_ATAPI,		"atapi" },
141 	{ ATA_DEV_ATAPI_UNSUP,		"atapi" },
142 	{ ATA_DEV_PMP,			"pmp" },
143 	{ ATA_DEV_PMP_UNSUP,		"pmp" },
144 	{ ATA_DEV_SEMB,			"semb" },
145 	{ ATA_DEV_SEMB_UNSUP,		"semb" },
146 	{ ATA_DEV_ZAC,			"zac" },
147 	{ ATA_DEV_NONE,			"none" }
148 };
149 ata_bitfield_name_search(class, ata_class_names)
150 
151 
152 static struct {
153 	u32		value;
154 	char		*name;
155 } ata_err_names[] = {
156 	{ AC_ERR_DEV,			"DeviceError" },
157 	{ AC_ERR_HSM,			"HostStateMachineError" },
158 	{ AC_ERR_TIMEOUT,		"Timeout" },
159 	{ AC_ERR_MEDIA,			"MediaError" },
160 	{ AC_ERR_ATA_BUS,		"BusError" },
161 	{ AC_ERR_HOST_BUS,		"HostBusError" },
162 	{ AC_ERR_SYSTEM,		"SystemError" },
163 	{ AC_ERR_INVALID,		"InvalidArg" },
164 	{ AC_ERR_OTHER,			"Unknown" },
165 	{ AC_ERR_NODEV_HINT,		"NoDeviceHint" },
166 	{ AC_ERR_NCQ,		 	"NCQError" }
167 };
168 ata_bitfield_name_match(err, ata_err_names)
169 
170 static struct {
171 	u32		value;
172 	char		*name;
173 } ata_xfer_names[] = {
174 	{ XFER_UDMA_7,			"XFER_UDMA_7" },
175 	{ XFER_UDMA_6,			"XFER_UDMA_6" },
176 	{ XFER_UDMA_5,			"XFER_UDMA_5" },
177 	{ XFER_UDMA_4,			"XFER_UDMA_4" },
178 	{ XFER_UDMA_3,			"XFER_UDMA_3" },
179 	{ XFER_UDMA_2,			"XFER_UDMA_2" },
180 	{ XFER_UDMA_1,			"XFER_UDMA_1" },
181 	{ XFER_UDMA_0,			"XFER_UDMA_0" },
182 	{ XFER_MW_DMA_4,		"XFER_MW_DMA_4" },
183 	{ XFER_MW_DMA_3,		"XFER_MW_DMA_3" },
184 	{ XFER_MW_DMA_2,		"XFER_MW_DMA_2" },
185 	{ XFER_MW_DMA_1,		"XFER_MW_DMA_1" },
186 	{ XFER_MW_DMA_0,		"XFER_MW_DMA_0" },
187 	{ XFER_SW_DMA_2,		"XFER_SW_DMA_2" },
188 	{ XFER_SW_DMA_1,		"XFER_SW_DMA_1" },
189 	{ XFER_SW_DMA_0,		"XFER_SW_DMA_0" },
190 	{ XFER_PIO_6,			"XFER_PIO_6" },
191 	{ XFER_PIO_5,			"XFER_PIO_5" },
192 	{ XFER_PIO_4,			"XFER_PIO_4" },
193 	{ XFER_PIO_3,			"XFER_PIO_3" },
194 	{ XFER_PIO_2,			"XFER_PIO_2" },
195 	{ XFER_PIO_1,			"XFER_PIO_1" },
196 	{ XFER_PIO_0,			"XFER_PIO_0" },
197 	{ XFER_PIO_SLOW,		"XFER_PIO_SLOW" }
198 };
199 ata_bitfield_name_match(xfer,ata_xfer_names)
200 
201 /*
202  * ATA Port attributes
203  */
204 #define ata_port_show_simple(field, name, format_string, cast)		\
205 static ssize_t								\
206 show_ata_port_##name(struct device *dev,				\
207 		     struct device_attribute *attr, char *buf)		\
208 {									\
209 	struct ata_port *ap = transport_class_to_port(dev);		\
210 									\
211 	return snprintf(buf, 20, format_string, cast ap->field);	\
212 }
213 
214 #define ata_port_simple_attr(field, name, format_string, type)		\
215 	ata_port_show_simple(field, name, format_string, (type))	\
216 static DEVICE_ATTR(name, S_IRUGO, show_ata_port_##name, NULL)
217 
218 ata_port_simple_attr(nr_pmp_links, nr_pmp_links, "%d\n", int);
219 ata_port_simple_attr(stats.idle_irq, idle_irq, "%ld\n", unsigned long);
220 ata_port_simple_attr(local_port_no, port_no, "%u\n", unsigned int);
221 
222 static DECLARE_TRANSPORT_CLASS(ata_port_class,
223 			       "ata_port", NULL, NULL, NULL);
224 
225 static void ata_tport_release(struct device *dev)
226 {
227 	put_device(dev->parent);
228 }
229 
230 /**
231  * ata_is_port --  check if a struct device represents a ATA port
232  * @dev:	device to check
233  *
234  * Returns:
235  *	%1 if the device represents a ATA Port, %0 else
236  */
237 static int ata_is_port(const struct device *dev)
238 {
239 	return dev->release == ata_tport_release;
240 }
241 
242 static int ata_tport_match(struct attribute_container *cont,
243 			   struct device *dev)
244 {
245 	if (!ata_is_port(dev))
246 		return 0;
247 	return &ata_scsi_transport_template->host_attrs.ac == cont;
248 }
249 
250 /**
251  * ata_tport_delete  --  remove ATA PORT
252  * @port:	ATA PORT to remove
253  *
254  * Removes the specified ATA PORT.  Remove the associated link as well.
255  */
256 void ata_tport_delete(struct ata_port *ap)
257 {
258 	struct device *dev = &ap->tdev;
259 
260 	ata_tlink_delete(&ap->link);
261 
262 	transport_remove_device(dev);
263 	device_del(dev);
264 	transport_destroy_device(dev);
265 	put_device(dev);
266 }
267 
268 /** ata_tport_add - initialize a transport ATA port structure
269  *
270  * @parent:	parent device
271  * @ap:		existing ata_port structure
272  *
273  * Initialize a ATA port structure for sysfs.  It will be added to the device
274  * tree below the device specified by @parent which could be a PCI device.
275  *
276  * Returns %0 on success
277  */
278 int ata_tport_add(struct device *parent,
279 		  struct ata_port *ap)
280 {
281 	int error;
282 	struct device *dev = &ap->tdev;
283 
284 	device_initialize(dev);
285 	dev->type = &ata_port_type;
286 
287 	dev->parent = get_device(parent);
288 	dev->release = ata_tport_release;
289 	dev_set_name(dev, "ata%d", ap->print_id);
290 	transport_setup_device(dev);
291 	ata_acpi_bind_port(ap);
292 	error = device_add(dev);
293 	if (error) {
294 		goto tport_err;
295 	}
296 
297 	device_enable_async_suspend(dev);
298 	pm_runtime_set_active(dev);
299 	pm_runtime_enable(dev);
300 	pm_runtime_forbid(dev);
301 
302 	transport_add_device(dev);
303 	transport_configure_device(dev);
304 
305 	error = ata_tlink_add(&ap->link);
306 	if (error) {
307 		goto tport_link_err;
308 	}
309 	return 0;
310 
311  tport_link_err:
312 	transport_remove_device(dev);
313 	device_del(dev);
314 
315  tport_err:
316 	transport_destroy_device(dev);
317 	put_device(dev);
318 	return error;
319 }
320 
321 
322 /*
323  * ATA link attributes
324  */
325 static int noop(int x) { return x; }
326 
327 #define ata_link_show_linkspeed(field, format)			        \
328 static ssize_t								\
329 show_ata_link_##field(struct device *dev,				\
330 		      struct device_attribute *attr, char *buf)		\
331 {									\
332 	struct ata_link *link = transport_class_to_link(dev);		\
333 									\
334 	return sprintf(buf, "%s\n", sata_spd_string(format(link->field))); \
335 }
336 
337 #define ata_link_linkspeed_attr(field, format)				\
338 	ata_link_show_linkspeed(field, format)				\
339 static DEVICE_ATTR(field, S_IRUGO, show_ata_link_##field, NULL)
340 
341 ata_link_linkspeed_attr(hw_sata_spd_limit, fls);
342 ata_link_linkspeed_attr(sata_spd_limit, fls);
343 ata_link_linkspeed_attr(sata_spd, noop);
344 
345 
346 static DECLARE_TRANSPORT_CLASS(ata_link_class,
347 		"ata_link", NULL, NULL, NULL);
348 
349 static void ata_tlink_release(struct device *dev)
350 {
351 	put_device(dev->parent);
352 }
353 
354 /**
355  * ata_is_link --  check if a struct device represents a ATA link
356  * @dev:	device to check
357  *
358  * Returns:
359  *	%1 if the device represents a ATA link, %0 else
360  */
361 static int ata_is_link(const struct device *dev)
362 {
363 	return dev->release == ata_tlink_release;
364 }
365 
366 static int ata_tlink_match(struct attribute_container *cont,
367 			   struct device *dev)
368 {
369 	struct ata_internal* i = to_ata_internal(ata_scsi_transport_template);
370 	if (!ata_is_link(dev))
371 		return 0;
372 	return &i->link_attr_cont.ac == cont;
373 }
374 
375 /**
376  * ata_tlink_delete  --  remove ATA LINK
377  * @port:	ATA LINK to remove
378  *
379  * Removes the specified ATA LINK.  remove associated ATA device(s) as well.
380  */
381 void ata_tlink_delete(struct ata_link *link)
382 {
383 	struct device *dev = &link->tdev;
384 	struct ata_device *ata_dev;
385 
386 	ata_for_each_dev(ata_dev, link, ALL) {
387 		ata_tdev_delete(ata_dev);
388 	}
389 
390 	transport_remove_device(dev);
391 	device_del(dev);
392 	transport_destroy_device(dev);
393 	put_device(dev);
394 }
395 
396 /**
397  * ata_tlink_add  --  initialize a transport ATA link structure
398  * @link:	allocated ata_link structure.
399  *
400  * Initialize an ATA LINK structure for sysfs.  It will be added in the
401  * device tree below the ATA PORT it belongs to.
402  *
403  * Returns %0 on success
404  */
405 int ata_tlink_add(struct ata_link *link)
406 {
407 	struct device *dev = &link->tdev;
408 	struct ata_port *ap = link->ap;
409 	struct ata_device *ata_dev;
410 	int error;
411 
412 	device_initialize(dev);
413 	dev->parent = get_device(&ap->tdev);
414 	dev->release = ata_tlink_release;
415 	if (ata_is_host_link(link))
416 		dev_set_name(dev, "link%d", ap->print_id);
417         else
418 		dev_set_name(dev, "link%d.%d", ap->print_id, link->pmp);
419 
420 	transport_setup_device(dev);
421 
422 	error = device_add(dev);
423 	if (error) {
424 		goto tlink_err;
425 	}
426 
427 	transport_add_device(dev);
428 	transport_configure_device(dev);
429 
430 	ata_for_each_dev(ata_dev, link, ALL) {
431 		error = ata_tdev_add(ata_dev);
432 		if (error) {
433 			goto tlink_dev_err;
434 		}
435 	}
436 	return 0;
437   tlink_dev_err:
438 	while (--ata_dev >= link->device) {
439 		ata_tdev_delete(ata_dev);
440 	}
441 	transport_remove_device(dev);
442 	device_del(dev);
443   tlink_err:
444 	transport_destroy_device(dev);
445 	put_device(dev);
446 	return error;
447 }
448 
449 /*
450  * ATA device attributes
451  */
452 
453 #define ata_dev_show_class(title, field)				\
454 static ssize_t								\
455 show_ata_dev_##field(struct device *dev,				\
456 		     struct device_attribute *attr, char *buf)		\
457 {									\
458 	struct ata_device *ata_dev = transport_class_to_dev(dev);	\
459 									\
460 	return get_ata_##title##_names(ata_dev->field, buf);		\
461 }
462 
463 #define ata_dev_attr(title, field)					\
464 	ata_dev_show_class(title, field)				\
465 static DEVICE_ATTR(field, S_IRUGO, show_ata_dev_##field, NULL)
466 
467 ata_dev_attr(class, class);
468 ata_dev_attr(xfer, pio_mode);
469 ata_dev_attr(xfer, dma_mode);
470 ata_dev_attr(xfer, xfer_mode);
471 
472 
473 #define ata_dev_show_simple(field, format_string, cast)		\
474 static ssize_t								\
475 show_ata_dev_##field(struct device *dev,				\
476 		     struct device_attribute *attr, char *buf)		\
477 {									\
478 	struct ata_device *ata_dev = transport_class_to_dev(dev);	\
479 									\
480 	return snprintf(buf, 20, format_string, cast ata_dev->field);	\
481 }
482 
483 #define ata_dev_simple_attr(field, format_string, type)	\
484 	ata_dev_show_simple(field, format_string, (type))	\
485 static DEVICE_ATTR(field, S_IRUGO, 			\
486 		   show_ata_dev_##field, NULL)
487 
488 ata_dev_simple_attr(spdn_cnt, "%d\n", int);
489 
490 struct ata_show_ering_arg {
491 	char* buf;
492 	int written;
493 };
494 
495 static int ata_show_ering(struct ata_ering_entry *ent, void *void_arg)
496 {
497 	struct ata_show_ering_arg* arg = void_arg;
498 	struct timespec time;
499 
500 	jiffies_to_timespec(ent->timestamp,&time);
501 	arg->written += sprintf(arg->buf + arg->written,
502 			       "[%5lu.%06lu]",
503 			       time.tv_sec, time.tv_nsec);
504 	arg->written += get_ata_err_names(ent->err_mask,
505 					  arg->buf + arg->written);
506 	return 0;
507 }
508 
509 static ssize_t
510 show_ata_dev_ering(struct device *dev,
511 		   struct device_attribute *attr, char *buf)
512 {
513 	struct ata_device *ata_dev = transport_class_to_dev(dev);
514 	struct ata_show_ering_arg arg = { buf, 0 };
515 
516 	ata_ering_map(&ata_dev->ering, ata_show_ering, &arg);
517 	return arg.written;
518 }
519 
520 
521 static DEVICE_ATTR(ering, S_IRUGO, show_ata_dev_ering, NULL);
522 
523 static ssize_t
524 show_ata_dev_id(struct device *dev,
525 		struct device_attribute *attr, char *buf)
526 {
527 	struct ata_device *ata_dev = transport_class_to_dev(dev);
528 	int written = 0, i = 0;
529 
530 	if (ata_dev->class == ATA_DEV_PMP)
531 		return 0;
532 	for(i=0;i<ATA_ID_WORDS;i++)  {
533 		written += snprintf(buf+written, 20, "%04x%c",
534 				    ata_dev->id[i],
535 				    ((i+1) & 7) ? ' ' : '\n');
536 	}
537 	return written;
538 }
539 
540 static DEVICE_ATTR(id, S_IRUGO, show_ata_dev_id, NULL);
541 
542 static ssize_t
543 show_ata_dev_gscr(struct device *dev,
544 		  struct device_attribute *attr, char *buf)
545 {
546 	struct ata_device *ata_dev = transport_class_to_dev(dev);
547 	int written = 0, i = 0;
548 
549 	if (ata_dev->class != ATA_DEV_PMP)
550 		return 0;
551 	for(i=0;i<SATA_PMP_GSCR_DWORDS;i++)  {
552 		written += snprintf(buf+written, 20, "%08x%c",
553 				    ata_dev->gscr[i],
554 				    ((i+1) & 3) ? ' ' : '\n');
555 	}
556 	if (SATA_PMP_GSCR_DWORDS & 3)
557 		buf[written-1] = '\n';
558 	return written;
559 }
560 
561 static DEVICE_ATTR(gscr, S_IRUGO, show_ata_dev_gscr, NULL);
562 
563 static DECLARE_TRANSPORT_CLASS(ata_dev_class,
564 			       "ata_device", NULL, NULL, NULL);
565 
566 static void ata_tdev_release(struct device *dev)
567 {
568 	put_device(dev->parent);
569 }
570 
571 /**
572  * ata_is_ata_dev  --  check if a struct device represents a ATA device
573  * @dev:	device to check
574  *
575  * Returns:
576  *	%1 if the device represents a ATA device, %0 else
577  */
578 static int ata_is_ata_dev(const struct device *dev)
579 {
580 	return dev->release == ata_tdev_release;
581 }
582 
583 static int ata_tdev_match(struct attribute_container *cont,
584 			  struct device *dev)
585 {
586 	struct ata_internal* i = to_ata_internal(ata_scsi_transport_template);
587 	if (!ata_is_ata_dev(dev))
588 		return 0;
589 	return &i->dev_attr_cont.ac == cont;
590 }
591 
592 /**
593  * ata_tdev_free  --  free a ATA LINK
594  * @dev:	ATA PHY to free
595  *
596  * Frees the specified ATA PHY.
597  *
598  * Note:
599  *   This function must only be called on a PHY that has not
600  *   successfully been added using ata_tdev_add().
601  */
602 static void ata_tdev_free(struct ata_device *dev)
603 {
604 	transport_destroy_device(&dev->tdev);
605 	put_device(&dev->tdev);
606 }
607 
608 /**
609  * ata_tdev_delete  --  remove ATA device
610  * @port:	ATA PORT to remove
611  *
612  * Removes the specified ATA device.
613  */
614 static void ata_tdev_delete(struct ata_device *ata_dev)
615 {
616 	struct device *dev = &ata_dev->tdev;
617 
618 	transport_remove_device(dev);
619 	device_del(dev);
620 	ata_tdev_free(ata_dev);
621 }
622 
623 
624 /**
625  * ata_tdev_add  --  initialize a transport ATA device structure.
626  * @ata_dev:	ata_dev structure.
627  *
628  * Initialize an ATA device structure for sysfs.  It will be added in the
629  * device tree below the ATA LINK device it belongs to.
630  *
631  * Returns %0 on success
632  */
633 static int ata_tdev_add(struct ata_device *ata_dev)
634 {
635 	struct device *dev = &ata_dev->tdev;
636 	struct ata_link *link = ata_dev->link;
637 	struct ata_port *ap = link->ap;
638 	int error;
639 
640 	device_initialize(dev);
641 	dev->parent = get_device(&link->tdev);
642 	dev->release = ata_tdev_release;
643 	if (ata_is_host_link(link))
644 		dev_set_name(dev, "dev%d.%d", ap->print_id,ata_dev->devno);
645         else
646 		dev_set_name(dev, "dev%d.%d.0", ap->print_id, link->pmp);
647 
648 	transport_setup_device(dev);
649 	ata_acpi_bind_dev(ata_dev);
650 	error = device_add(dev);
651 	if (error) {
652 		ata_tdev_free(ata_dev);
653 		return error;
654 	}
655 
656 	transport_add_device(dev);
657 	transport_configure_device(dev);
658 	return 0;
659 }
660 
661 
662 /*
663  * Setup / Teardown code
664  */
665 
666 #define SETUP_TEMPLATE(attrb, field, perm, test)			\
667 	i->private_##attrb[count] = dev_attr_##field;		       	\
668 	i->private_##attrb[count].attr.mode = perm;			\
669 	i->attrb[count] = &i->private_##attrb[count];			\
670 	if (test)							\
671 		count++
672 
673 #define SETUP_LINK_ATTRIBUTE(field)					\
674 	SETUP_TEMPLATE(link_attrs, field, S_IRUGO, 1)
675 
676 #define SETUP_PORT_ATTRIBUTE(field)					\
677 	SETUP_TEMPLATE(port_attrs, field, S_IRUGO, 1)
678 
679 #define SETUP_DEV_ATTRIBUTE(field)					\
680 	SETUP_TEMPLATE(dev_attrs, field, S_IRUGO, 1)
681 
682 /**
683  * ata_attach_transport  --  instantiate ATA transport template
684  */
685 struct scsi_transport_template *ata_attach_transport(void)
686 {
687 	struct ata_internal *i;
688 	int count;
689 
690 	i = kzalloc(sizeof(struct ata_internal), GFP_KERNEL);
691 	if (!i)
692 		return NULL;
693 
694 	i->t.eh_strategy_handler	= ata_scsi_error;
695 	i->t.eh_timed_out		= ata_scsi_timed_out;
696 	i->t.user_scan			= ata_scsi_user_scan;
697 
698 	i->t.host_attrs.ac.attrs = &i->port_attrs[0];
699 	i->t.host_attrs.ac.class = &ata_port_class.class;
700 	i->t.host_attrs.ac.match = ata_tport_match;
701 	transport_container_register(&i->t.host_attrs);
702 
703 	i->link_attr_cont.ac.class = &ata_link_class.class;
704 	i->link_attr_cont.ac.attrs = &i->link_attrs[0];
705 	i->link_attr_cont.ac.match = ata_tlink_match;
706 	transport_container_register(&i->link_attr_cont);
707 
708 	i->dev_attr_cont.ac.class = &ata_dev_class.class;
709 	i->dev_attr_cont.ac.attrs = &i->dev_attrs[0];
710 	i->dev_attr_cont.ac.match = ata_tdev_match;
711 	transport_container_register(&i->dev_attr_cont);
712 
713 	count = 0;
714 	SETUP_PORT_ATTRIBUTE(nr_pmp_links);
715 	SETUP_PORT_ATTRIBUTE(idle_irq);
716 	SETUP_PORT_ATTRIBUTE(port_no);
717 	BUG_ON(count > ATA_PORT_ATTRS);
718 	i->port_attrs[count] = NULL;
719 
720 	count = 0;
721 	SETUP_LINK_ATTRIBUTE(hw_sata_spd_limit);
722 	SETUP_LINK_ATTRIBUTE(sata_spd_limit);
723 	SETUP_LINK_ATTRIBUTE(sata_spd);
724 	BUG_ON(count > ATA_LINK_ATTRS);
725 	i->link_attrs[count] = NULL;
726 
727 	count = 0;
728 	SETUP_DEV_ATTRIBUTE(class);
729 	SETUP_DEV_ATTRIBUTE(pio_mode);
730 	SETUP_DEV_ATTRIBUTE(dma_mode);
731 	SETUP_DEV_ATTRIBUTE(xfer_mode);
732 	SETUP_DEV_ATTRIBUTE(spdn_cnt);
733 	SETUP_DEV_ATTRIBUTE(ering);
734 	SETUP_DEV_ATTRIBUTE(id);
735 	SETUP_DEV_ATTRIBUTE(gscr);
736 	BUG_ON(count > ATA_DEV_ATTRS);
737 	i->dev_attrs[count] = NULL;
738 
739 	return &i->t;
740 }
741 
742 /**
743  * ata_release_transport  --  release ATA transport template instance
744  * @t:		transport template instance
745  */
746 void ata_release_transport(struct scsi_transport_template *t)
747 {
748 	struct ata_internal *i = to_ata_internal(t);
749 
750 	transport_container_unregister(&i->t.host_attrs);
751 	transport_container_unregister(&i->link_attr_cont);
752 	transport_container_unregister(&i->dev_attr_cont);
753 
754 	kfree(i);
755 }
756 
757 __init int libata_transport_init(void)
758 {
759 	int error;
760 
761 	error = transport_class_register(&ata_link_class);
762 	if (error)
763 		goto out_unregister_transport;
764 	error = transport_class_register(&ata_port_class);
765 	if (error)
766 		goto out_unregister_link;
767 	error = transport_class_register(&ata_dev_class);
768 	if (error)
769 		goto out_unregister_port;
770 	return 0;
771 
772  out_unregister_port:
773 	transport_class_unregister(&ata_port_class);
774  out_unregister_link:
775 	transport_class_unregister(&ata_link_class);
776  out_unregister_transport:
777 	return error;
778 
779 }
780 
781 void __exit libata_transport_exit(void)
782 {
783 	transport_class_unregister(&ata_link_class);
784 	transport_class_unregister(&ata_port_class);
785 	transport_class_unregister(&ata_dev_class);
786 }
787