xref: /linux/drivers/firewire/sbp2.c (revision 363c55cae53742f3f685a1814912c6d4fda245b4)
1 /*
2  * SBP2 driver (SCSI over IEEE1394)
3  *
4  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 /*
22  * The basic structure of this driver is based on the old storage driver,
23  * drivers/ieee1394/sbp2.c, originally written by
24  *     James Goodwin <jamesg@filanet.com>
25  * with later contributions and ongoing maintenance from
26  *     Ben Collins <bcollins@debian.org>,
27  *     Stefan Richter <stefanr@s5r6.in-berlin.de>
28  * and many others.
29  */
30 
31 #include <linux/blkdev.h>
32 #include <linux/bug.h>
33 #include <linux/completion.h>
34 #include <linux/delay.h>
35 #include <linux/device.h>
36 #include <linux/dma-mapping.h>
37 #include <linux/firewire.h>
38 #include <linux/firewire-constants.h>
39 #include <linux/init.h>
40 #include <linux/jiffies.h>
41 #include <linux/kernel.h>
42 #include <linux/kref.h>
43 #include <linux/list.h>
44 #include <linux/mod_devicetable.h>
45 #include <linux/module.h>
46 #include <linux/moduleparam.h>
47 #include <linux/scatterlist.h>
48 #include <linux/slab.h>
49 #include <linux/spinlock.h>
50 #include <linux/string.h>
51 #include <linux/stringify.h>
52 #include <linux/workqueue.h>
53 
54 #include <asm/byteorder.h>
55 #include <asm/system.h>
56 
57 #include <scsi/scsi.h>
58 #include <scsi/scsi_cmnd.h>
59 #include <scsi/scsi_device.h>
60 #include <scsi/scsi_host.h>
61 
62 /*
63  * So far only bridges from Oxford Semiconductor are known to support
64  * concurrent logins. Depending on firmware, four or two concurrent logins
65  * are possible on OXFW911 and newer Oxsemi bridges.
66  *
67  * Concurrent logins are useful together with cluster filesystems.
68  */
69 static int sbp2_param_exclusive_login = 1;
70 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
71 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
72 		 "(default = Y, use N for concurrent initiators)");
73 
74 /*
75  * Flags for firmware oddities
76  *
77  * - 128kB max transfer
78  *   Limit transfer size. Necessary for some old bridges.
79  *
80  * - 36 byte inquiry
81  *   When scsi_mod probes the device, let the inquiry command look like that
82  *   from MS Windows.
83  *
84  * - skip mode page 8
85  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
86  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
87  *
88  * - fix capacity
89  *   Tell sd_mod to correct the last sector number reported by read_capacity.
90  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
91  *   Don't use this with devices which don't have this bug.
92  *
93  * - delay inquiry
94  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
95  *
96  * - power condition
97  *   Set the power condition field in the START STOP UNIT commands sent by
98  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
99  *   Some disks need this to spin down or to resume properly.
100  *
101  * - override internal blacklist
102  *   Instead of adding to the built-in blacklist, use only the workarounds
103  *   specified in the module load parameter.
104  *   Useful if a blacklist entry interfered with a non-broken device.
105  */
106 #define SBP2_WORKAROUND_128K_MAX_TRANS	0x1
107 #define SBP2_WORKAROUND_INQUIRY_36	0x2
108 #define SBP2_WORKAROUND_MODE_SENSE_8	0x4
109 #define SBP2_WORKAROUND_FIX_CAPACITY	0x8
110 #define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
111 #define SBP2_INQUIRY_DELAY		12
112 #define SBP2_WORKAROUND_POWER_CONDITION	0x20
113 #define SBP2_WORKAROUND_OVERRIDE	0x100
114 
115 static int sbp2_param_workarounds;
116 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
117 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
118 	", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
119 	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
120 	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
121 	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
122 	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
123 	", set power condition in start stop unit = "
124 				  __stringify(SBP2_WORKAROUND_POWER_CONDITION)
125 	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
126 	", or a combination)");
127 
128 /* I don't know why the SCSI stack doesn't define something like this... */
129 typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
130 
131 static const char sbp2_driver_name[] = "sbp2";
132 
133 /*
134  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
135  * and one struct scsi_device per sbp2_logical_unit.
136  */
137 struct sbp2_logical_unit {
138 	struct sbp2_target *tgt;
139 	struct list_head link;
140 	struct fw_address_handler address_handler;
141 	struct list_head orb_list;
142 
143 	u64 command_block_agent_address;
144 	u16 lun;
145 	int login_id;
146 
147 	/*
148 	 * The generation is updated once we've logged in or reconnected
149 	 * to the logical unit.  Thus, I/O to the device will automatically
150 	 * fail and get retried if it happens in a window where the device
151 	 * is not ready, e.g. after a bus reset but before we reconnect.
152 	 */
153 	int generation;
154 	int retries;
155 	struct delayed_work work;
156 	bool has_sdev;
157 	bool blocked;
158 };
159 
160 /*
161  * We create one struct sbp2_target per IEEE 1212 Unit Directory
162  * and one struct Scsi_Host per sbp2_target.
163  */
164 struct sbp2_target {
165 	struct kref kref;
166 	struct fw_unit *unit;
167 	const char *bus_id;
168 	struct list_head lu_list;
169 
170 	u64 management_agent_address;
171 	u64 guid;
172 	int directory_id;
173 	int node_id;
174 	int address_high;
175 	unsigned int workarounds;
176 	unsigned int mgt_orb_timeout;
177 	unsigned int max_payload;
178 
179 	int dont_block;	/* counter for each logical unit */
180 	int blocked;	/* ditto */
181 };
182 
183 static struct fw_device *target_device(struct sbp2_target *tgt)
184 {
185 	return fw_parent_device(tgt->unit);
186 }
187 
188 /* Impossible login_id, to detect logout attempt before successful login */
189 #define INVALID_LOGIN_ID 0x10000
190 
191 /*
192  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
193  * provided in the config rom. Most devices do provide a value, which
194  * we'll use for login management orbs, but with some sane limits.
195  */
196 #define SBP2_MIN_LOGIN_ORB_TIMEOUT	5000U	/* Timeout in ms */
197 #define SBP2_MAX_LOGIN_ORB_TIMEOUT	40000U	/* Timeout in ms */
198 #define SBP2_ORB_TIMEOUT		2000U	/* Timeout in ms */
199 #define SBP2_ORB_NULL			0x80000000
200 #define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
201 #define SBP2_CYCLE_LIMIT		(0xc8 << 12)	/* 200 125us cycles */
202 
203 /*
204  * The default maximum s/g segment size of a FireWire controller is
205  * usually 0x10000, but SBP-2 only allows 0xffff. Since buffers have to
206  * be quadlet-aligned, we set the length limit to 0xffff & ~3.
207  */
208 #define SBP2_MAX_SEG_SIZE		0xfffc
209 
210 /* Unit directory keys */
211 #define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
212 #define SBP2_CSR_FIRMWARE_REVISION	0x3c
213 #define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
214 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4
215 
216 /* Management orb opcodes */
217 #define SBP2_LOGIN_REQUEST		0x0
218 #define SBP2_QUERY_LOGINS_REQUEST	0x1
219 #define SBP2_RECONNECT_REQUEST		0x3
220 #define SBP2_SET_PASSWORD_REQUEST	0x4
221 #define SBP2_LOGOUT_REQUEST		0x7
222 #define SBP2_ABORT_TASK_REQUEST		0xb
223 #define SBP2_ABORT_TASK_SET		0xc
224 #define SBP2_LOGICAL_UNIT_RESET		0xe
225 #define SBP2_TARGET_RESET_REQUEST	0xf
226 
227 /* Offsets for command block agent registers */
228 #define SBP2_AGENT_STATE		0x00
229 #define SBP2_AGENT_RESET		0x04
230 #define SBP2_ORB_POINTER		0x08
231 #define SBP2_DOORBELL			0x10
232 #define SBP2_UNSOLICITED_STATUS_ENABLE	0x14
233 
234 /* Status write response codes */
235 #define SBP2_STATUS_REQUEST_COMPLETE	0x0
236 #define SBP2_STATUS_TRANSPORT_FAILURE	0x1
237 #define SBP2_STATUS_ILLEGAL_REQUEST	0x2
238 #define SBP2_STATUS_VENDOR_DEPENDENT	0x3
239 
240 #define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
241 #define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
242 #define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
243 #define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
244 #define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
245 #define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
246 #define STATUS_GET_ORB_LOW(v)		((v).orb_low)
247 #define STATUS_GET_DATA(v)		((v).data)
248 
249 struct sbp2_status {
250 	u32 status;
251 	u32 orb_low;
252 	u8 data[24];
253 };
254 
255 struct sbp2_pointer {
256 	__be32 high;
257 	__be32 low;
258 };
259 
260 struct sbp2_orb {
261 	struct fw_transaction t;
262 	struct kref kref;
263 	dma_addr_t request_bus;
264 	int rcode;
265 	struct sbp2_pointer pointer;
266 	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
267 	struct list_head link;
268 };
269 
270 #define MANAGEMENT_ORB_LUN(v)			((v))
271 #define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
272 #define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
273 #define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
274 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
275 #define MANAGEMENT_ORB_NOTIFY			((1) << 31)
276 
277 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
278 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
279 
280 struct sbp2_management_orb {
281 	struct sbp2_orb base;
282 	struct {
283 		struct sbp2_pointer password;
284 		struct sbp2_pointer response;
285 		__be32 misc;
286 		__be32 length;
287 		struct sbp2_pointer status_fifo;
288 	} request;
289 	__be32 response[4];
290 	dma_addr_t response_bus;
291 	struct completion done;
292 	struct sbp2_status status;
293 };
294 
295 struct sbp2_login_response {
296 	__be32 misc;
297 	struct sbp2_pointer command_block_agent;
298 	__be32 reconnect_hold;
299 };
300 #define COMMAND_ORB_DATA_SIZE(v)	((v))
301 #define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
302 #define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
303 #define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
304 #define COMMAND_ORB_SPEED(v)		((v) << 24)
305 #define COMMAND_ORB_DIRECTION		((1) << 27)
306 #define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
307 #define COMMAND_ORB_NOTIFY		((1) << 31)
308 
309 struct sbp2_command_orb {
310 	struct sbp2_orb base;
311 	struct {
312 		struct sbp2_pointer next;
313 		struct sbp2_pointer data_descriptor;
314 		__be32 misc;
315 		u8 command_block[12];
316 	} request;
317 	struct scsi_cmnd *cmd;
318 	scsi_done_fn_t done;
319 	struct sbp2_logical_unit *lu;
320 
321 	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
322 	dma_addr_t page_table_bus;
323 };
324 
325 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
326 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
327 
328 /*
329  * List of devices with known bugs.
330  *
331  * The firmware_revision field, masked with 0xffff00, is the best
332  * indicator for the type of bridge chip of a device.  It yields a few
333  * false positives but this did not break correctly behaving devices
334  * so far.
335  */
336 static const struct {
337 	u32 firmware_revision;
338 	u32 model;
339 	unsigned int workarounds;
340 } sbp2_workarounds_table[] = {
341 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
342 		.firmware_revision	= 0x002800,
343 		.model			= 0x001010,
344 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
345 					  SBP2_WORKAROUND_MODE_SENSE_8 |
346 					  SBP2_WORKAROUND_POWER_CONDITION,
347 	},
348 	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
349 		.firmware_revision	= 0x002800,
350 		.model			= 0x000000,
351 		.workarounds		= SBP2_WORKAROUND_DELAY_INQUIRY |
352 					  SBP2_WORKAROUND_POWER_CONDITION,
353 	},
354 	/* Initio bridges, actually only needed for some older ones */ {
355 		.firmware_revision	= 0x000200,
356 		.model			= SBP2_ROM_VALUE_WILDCARD,
357 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
358 	},
359 	/* PL-3507 bridge with Prolific firmware */ {
360 		.firmware_revision	= 0x012800,
361 		.model			= SBP2_ROM_VALUE_WILDCARD,
362 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
363 	},
364 	/* Symbios bridge */ {
365 		.firmware_revision	= 0xa0b800,
366 		.model			= SBP2_ROM_VALUE_WILDCARD,
367 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
368 	},
369 	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
370 		.firmware_revision	= 0x002600,
371 		.model			= SBP2_ROM_VALUE_WILDCARD,
372 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
373 	},
374 	/*
375 	 * iPod 2nd generation: needs 128k max transfer size workaround
376 	 * iPod 3rd generation: needs fix capacity workaround
377 	 */
378 	{
379 		.firmware_revision	= 0x0a2700,
380 		.model			= 0x000000,
381 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
382 					  SBP2_WORKAROUND_FIX_CAPACITY,
383 	},
384 	/* iPod 4th generation */ {
385 		.firmware_revision	= 0x0a2700,
386 		.model			= 0x000021,
387 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
388 	},
389 	/* iPod mini */ {
390 		.firmware_revision	= 0x0a2700,
391 		.model			= 0x000022,
392 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
393 	},
394 	/* iPod mini */ {
395 		.firmware_revision	= 0x0a2700,
396 		.model			= 0x000023,
397 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
398 	},
399 	/* iPod Photo */ {
400 		.firmware_revision	= 0x0a2700,
401 		.model			= 0x00007e,
402 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
403 	}
404 };
405 
406 static void free_orb(struct kref *kref)
407 {
408 	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
409 
410 	kfree(orb);
411 }
412 
413 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
414 			      int tcode, int destination, int source,
415 			      int generation, int speed,
416 			      unsigned long long offset,
417 			      void *payload, size_t length, void *callback_data)
418 {
419 	struct sbp2_logical_unit *lu = callback_data;
420 	struct sbp2_orb *orb;
421 	struct sbp2_status status;
422 	size_t header_size;
423 	unsigned long flags;
424 
425 	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
426 	    length == 0 || length > sizeof(status)) {
427 		fw_send_response(card, request, RCODE_TYPE_ERROR);
428 		return;
429 	}
430 
431 	header_size = min(length, 2 * sizeof(u32));
432 	fw_memcpy_from_be32(&status, payload, header_size);
433 	if (length > header_size)
434 		memcpy(status.data, payload + 8, length - header_size);
435 	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
436 		fw_notify("non-orb related status write, not handled\n");
437 		fw_send_response(card, request, RCODE_COMPLETE);
438 		return;
439 	}
440 
441 	/* Lookup the orb corresponding to this status write. */
442 	spin_lock_irqsave(&card->lock, flags);
443 	list_for_each_entry(orb, &lu->orb_list, link) {
444 		if (STATUS_GET_ORB_HIGH(status) == 0 &&
445 		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
446 			orb->rcode = RCODE_COMPLETE;
447 			list_del(&orb->link);
448 			break;
449 		}
450 	}
451 	spin_unlock_irqrestore(&card->lock, flags);
452 
453 	if (&orb->link != &lu->orb_list)
454 		orb->callback(orb, &status);
455 	else
456 		fw_error("status write for unknown orb\n");
457 
458 	kref_put(&orb->kref, free_orb);
459 
460 	fw_send_response(card, request, RCODE_COMPLETE);
461 }
462 
463 static void complete_transaction(struct fw_card *card, int rcode,
464 				 void *payload, size_t length, void *data)
465 {
466 	struct sbp2_orb *orb = data;
467 	unsigned long flags;
468 
469 	/*
470 	 * This is a little tricky.  We can get the status write for
471 	 * the orb before we get this callback.  The status write
472 	 * handler above will assume the orb pointer transaction was
473 	 * successful and set the rcode to RCODE_COMPLETE for the orb.
474 	 * So this callback only sets the rcode if it hasn't already
475 	 * been set and only does the cleanup if the transaction
476 	 * failed and we didn't already get a status write.
477 	 */
478 	spin_lock_irqsave(&card->lock, flags);
479 
480 	if (orb->rcode == -1)
481 		orb->rcode = rcode;
482 	if (orb->rcode != RCODE_COMPLETE) {
483 		list_del(&orb->link);
484 		spin_unlock_irqrestore(&card->lock, flags);
485 		orb->callback(orb, NULL);
486 	} else {
487 		spin_unlock_irqrestore(&card->lock, flags);
488 	}
489 
490 	kref_put(&orb->kref, free_orb);
491 }
492 
493 static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
494 			  int node_id, int generation, u64 offset)
495 {
496 	struct fw_device *device = target_device(lu->tgt);
497 	unsigned long flags;
498 
499 	orb->pointer.high = 0;
500 	orb->pointer.low = cpu_to_be32(orb->request_bus);
501 
502 	spin_lock_irqsave(&device->card->lock, flags);
503 	list_add_tail(&orb->link, &lu->orb_list);
504 	spin_unlock_irqrestore(&device->card->lock, flags);
505 
506 	/* Take a ref for the orb list and for the transaction callback. */
507 	kref_get(&orb->kref);
508 	kref_get(&orb->kref);
509 
510 	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
511 			node_id, generation, device->max_speed, offset,
512 			&orb->pointer, sizeof(orb->pointer),
513 			complete_transaction, orb);
514 }
515 
516 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
517 {
518 	struct fw_device *device = target_device(lu->tgt);
519 	struct sbp2_orb *orb, *next;
520 	struct list_head list;
521 	unsigned long flags;
522 	int retval = -ENOENT;
523 
524 	INIT_LIST_HEAD(&list);
525 	spin_lock_irqsave(&device->card->lock, flags);
526 	list_splice_init(&lu->orb_list, &list);
527 	spin_unlock_irqrestore(&device->card->lock, flags);
528 
529 	list_for_each_entry_safe(orb, next, &list, link) {
530 		retval = 0;
531 		if (fw_cancel_transaction(device->card, &orb->t) == 0)
532 			continue;
533 
534 		orb->rcode = RCODE_CANCELLED;
535 		orb->callback(orb, NULL);
536 	}
537 
538 	return retval;
539 }
540 
541 static void complete_management_orb(struct sbp2_orb *base_orb,
542 				    struct sbp2_status *status)
543 {
544 	struct sbp2_management_orb *orb =
545 		container_of(base_orb, struct sbp2_management_orb, base);
546 
547 	if (status)
548 		memcpy(&orb->status, status, sizeof(*status));
549 	complete(&orb->done);
550 }
551 
552 static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
553 				    int generation, int function,
554 				    int lun_or_login_id, void *response)
555 {
556 	struct fw_device *device = target_device(lu->tgt);
557 	struct sbp2_management_orb *orb;
558 	unsigned int timeout;
559 	int retval = -ENOMEM;
560 
561 	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
562 		return 0;
563 
564 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
565 	if (orb == NULL)
566 		return -ENOMEM;
567 
568 	kref_init(&orb->base.kref);
569 	orb->response_bus =
570 		dma_map_single(device->card->device, &orb->response,
571 			       sizeof(orb->response), DMA_FROM_DEVICE);
572 	if (dma_mapping_error(device->card->device, orb->response_bus))
573 		goto fail_mapping_response;
574 
575 	orb->request.response.high = 0;
576 	orb->request.response.low  = cpu_to_be32(orb->response_bus);
577 
578 	orb->request.misc = cpu_to_be32(
579 		MANAGEMENT_ORB_NOTIFY |
580 		MANAGEMENT_ORB_FUNCTION(function) |
581 		MANAGEMENT_ORB_LUN(lun_or_login_id));
582 	orb->request.length = cpu_to_be32(
583 		MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
584 
585 	orb->request.status_fifo.high =
586 		cpu_to_be32(lu->address_handler.offset >> 32);
587 	orb->request.status_fifo.low  =
588 		cpu_to_be32(lu->address_handler.offset);
589 
590 	if (function == SBP2_LOGIN_REQUEST) {
591 		/* Ask for 2^2 == 4 seconds reconnect grace period */
592 		orb->request.misc |= cpu_to_be32(
593 			MANAGEMENT_ORB_RECONNECT(2) |
594 			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
595 		timeout = lu->tgt->mgt_orb_timeout;
596 	} else {
597 		timeout = SBP2_ORB_TIMEOUT;
598 	}
599 
600 	init_completion(&orb->done);
601 	orb->base.callback = complete_management_orb;
602 
603 	orb->base.request_bus =
604 		dma_map_single(device->card->device, &orb->request,
605 			       sizeof(orb->request), DMA_TO_DEVICE);
606 	if (dma_mapping_error(device->card->device, orb->base.request_bus))
607 		goto fail_mapping_request;
608 
609 	sbp2_send_orb(&orb->base, lu, node_id, generation,
610 		      lu->tgt->management_agent_address);
611 
612 	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
613 
614 	retval = -EIO;
615 	if (sbp2_cancel_orbs(lu) == 0) {
616 		fw_error("%s: orb reply timed out, rcode=0x%02x\n",
617 			 lu->tgt->bus_id, orb->base.rcode);
618 		goto out;
619 	}
620 
621 	if (orb->base.rcode != RCODE_COMPLETE) {
622 		fw_error("%s: management write failed, rcode 0x%02x\n",
623 			 lu->tgt->bus_id, orb->base.rcode);
624 		goto out;
625 	}
626 
627 	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
628 	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
629 		fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
630 			 STATUS_GET_RESPONSE(orb->status),
631 			 STATUS_GET_SBP_STATUS(orb->status));
632 		goto out;
633 	}
634 
635 	retval = 0;
636  out:
637 	dma_unmap_single(device->card->device, orb->base.request_bus,
638 			 sizeof(orb->request), DMA_TO_DEVICE);
639  fail_mapping_request:
640 	dma_unmap_single(device->card->device, orb->response_bus,
641 			 sizeof(orb->response), DMA_FROM_DEVICE);
642  fail_mapping_response:
643 	if (response)
644 		memcpy(response, orb->response, sizeof(orb->response));
645 	kref_put(&orb->base.kref, free_orb);
646 
647 	return retval;
648 }
649 
650 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
651 {
652 	struct fw_device *device = target_device(lu->tgt);
653 	__be32 d = 0;
654 
655 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
656 			   lu->tgt->node_id, lu->generation, device->max_speed,
657 			   lu->command_block_agent_address + SBP2_AGENT_RESET,
658 			   &d, sizeof(d));
659 }
660 
661 static void complete_agent_reset_write_no_wait(struct fw_card *card,
662 		int rcode, void *payload, size_t length, void *data)
663 {
664 	kfree(data);
665 }
666 
667 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
668 {
669 	struct fw_device *device = target_device(lu->tgt);
670 	struct fw_transaction *t;
671 	static __be32 d;
672 
673 	t = kmalloc(sizeof(*t), GFP_ATOMIC);
674 	if (t == NULL)
675 		return;
676 
677 	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
678 			lu->tgt->node_id, lu->generation, device->max_speed,
679 			lu->command_block_agent_address + SBP2_AGENT_RESET,
680 			&d, sizeof(d), complete_agent_reset_write_no_wait, t);
681 }
682 
683 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
684 {
685 	/*
686 	 * We may access dont_block without taking card->lock here:
687 	 * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
688 	 * are currently serialized against each other.
689 	 * And a wrong result in sbp2_conditionally_block()'s access of
690 	 * dont_block is rather harmless, it simply misses its first chance.
691 	 */
692 	--lu->tgt->dont_block;
693 }
694 
695 /*
696  * Blocks lu->tgt if all of the following conditions are met:
697  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
698  *     logical units have been finished (indicated by dont_block == 0).
699  *   - lu->generation is stale.
700  *
701  * Note, scsi_block_requests() must be called while holding card->lock,
702  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
703  * unblock the target.
704  */
705 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
706 {
707 	struct sbp2_target *tgt = lu->tgt;
708 	struct fw_card *card = target_device(tgt)->card;
709 	struct Scsi_Host *shost =
710 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
711 	unsigned long flags;
712 
713 	spin_lock_irqsave(&card->lock, flags);
714 	if (!tgt->dont_block && !lu->blocked &&
715 	    lu->generation != card->generation) {
716 		lu->blocked = true;
717 		if (++tgt->blocked == 1)
718 			scsi_block_requests(shost);
719 	}
720 	spin_unlock_irqrestore(&card->lock, flags);
721 }
722 
723 /*
724  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
725  * Note, it is harmless to run scsi_unblock_requests() outside the
726  * card->lock protected section.  On the other hand, running it inside
727  * the section might clash with shost->host_lock.
728  */
729 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
730 {
731 	struct sbp2_target *tgt = lu->tgt;
732 	struct fw_card *card = target_device(tgt)->card;
733 	struct Scsi_Host *shost =
734 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
735 	unsigned long flags;
736 	bool unblock = false;
737 
738 	spin_lock_irqsave(&card->lock, flags);
739 	if (lu->blocked && lu->generation == card->generation) {
740 		lu->blocked = false;
741 		unblock = --tgt->blocked == 0;
742 	}
743 	spin_unlock_irqrestore(&card->lock, flags);
744 
745 	if (unblock)
746 		scsi_unblock_requests(shost);
747 }
748 
749 /*
750  * Prevents future blocking of tgt and unblocks it.
751  * Note, it is harmless to run scsi_unblock_requests() outside the
752  * card->lock protected section.  On the other hand, running it inside
753  * the section might clash with shost->host_lock.
754  */
755 static void sbp2_unblock(struct sbp2_target *tgt)
756 {
757 	struct fw_card *card = target_device(tgt)->card;
758 	struct Scsi_Host *shost =
759 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
760 	unsigned long flags;
761 
762 	spin_lock_irqsave(&card->lock, flags);
763 	++tgt->dont_block;
764 	spin_unlock_irqrestore(&card->lock, flags);
765 
766 	scsi_unblock_requests(shost);
767 }
768 
769 static int sbp2_lun2int(u16 lun)
770 {
771 	struct scsi_lun eight_bytes_lun;
772 
773 	memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
774 	eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
775 	eight_bytes_lun.scsi_lun[1] = lun & 0xff;
776 
777 	return scsilun_to_int(&eight_bytes_lun);
778 }
779 
780 static void sbp2_release_target(struct kref *kref)
781 {
782 	struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
783 	struct sbp2_logical_unit *lu, *next;
784 	struct Scsi_Host *shost =
785 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
786 	struct scsi_device *sdev;
787 	struct fw_device *device = target_device(tgt);
788 
789 	/* prevent deadlocks */
790 	sbp2_unblock(tgt);
791 
792 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
793 		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
794 		if (sdev) {
795 			scsi_remove_device(sdev);
796 			scsi_device_put(sdev);
797 		}
798 		if (lu->login_id != INVALID_LOGIN_ID) {
799 			int generation, node_id;
800 			/*
801 			 * tgt->node_id may be obsolete here if we failed
802 			 * during initial login or after a bus reset where
803 			 * the topology changed.
804 			 */
805 			generation = device->generation;
806 			smp_rmb(); /* node_id vs. generation */
807 			node_id    = device->node_id;
808 			sbp2_send_management_orb(lu, node_id, generation,
809 						 SBP2_LOGOUT_REQUEST,
810 						 lu->login_id, NULL);
811 		}
812 		fw_core_remove_address_handler(&lu->address_handler);
813 		list_del(&lu->link);
814 		kfree(lu);
815 	}
816 	scsi_remove_host(shost);
817 	fw_notify("released %s, target %d:0:0\n", tgt->bus_id, shost->host_no);
818 
819 	fw_unit_put(tgt->unit);
820 	scsi_host_put(shost);
821 	fw_device_put(device);
822 }
823 
824 static struct workqueue_struct *sbp2_wq;
825 
826 static void sbp2_target_put(struct sbp2_target *tgt)
827 {
828 	kref_put(&tgt->kref, sbp2_release_target);
829 }
830 
831 /*
832  * Always get the target's kref when scheduling work on one its units.
833  * Each workqueue job is responsible to call sbp2_target_put() upon return.
834  */
835 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
836 {
837 	kref_get(&lu->tgt->kref);
838 	if (!queue_delayed_work(sbp2_wq, &lu->work, delay))
839 		sbp2_target_put(lu->tgt);
840 }
841 
842 /*
843  * Write retransmit retry values into the BUSY_TIMEOUT register.
844  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
845  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
846  *   saner value after logging into the device.
847  * - The dual-phase retry protocol is optional to implement, and if not
848  *   supported, writes to the dual-phase portion of the register will be
849  *   ignored. We try to write the original 1394-1995 default here.
850  * - In the case of devices that are also SBP-3-compliant, all writes are
851  *   ignored, as the register is read-only, but contains single-phase retry of
852  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
853  *   write attempt is safe and yields more consistent behavior for all devices.
854  *
855  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
856  * and section 6.4 of the SBP-3 spec for further details.
857  */
858 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
859 {
860 	struct fw_device *device = target_device(lu->tgt);
861 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
862 
863 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
864 			   lu->tgt->node_id, lu->generation, device->max_speed,
865 			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT,
866 			   &d, sizeof(d));
867 }
868 
869 static void sbp2_reconnect(struct work_struct *work);
870 
871 static void sbp2_login(struct work_struct *work)
872 {
873 	struct sbp2_logical_unit *lu =
874 		container_of(work, struct sbp2_logical_unit, work.work);
875 	struct sbp2_target *tgt = lu->tgt;
876 	struct fw_device *device = target_device(tgt);
877 	struct Scsi_Host *shost;
878 	struct scsi_device *sdev;
879 	struct sbp2_login_response response;
880 	int generation, node_id, local_node_id;
881 
882 	if (fw_device_is_shutdown(device))
883 		goto out;
884 
885 	generation    = device->generation;
886 	smp_rmb();    /* node IDs must not be older than generation */
887 	node_id       = device->node_id;
888 	local_node_id = device->card->node_id;
889 
890 	/* If this is a re-login attempt, log out, or we might be rejected. */
891 	if (lu->has_sdev)
892 		sbp2_send_management_orb(lu, device->node_id, generation,
893 				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
894 
895 	if (sbp2_send_management_orb(lu, node_id, generation,
896 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
897 		if (lu->retries++ < 5) {
898 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
899 		} else {
900 			fw_error("%s: failed to login to LUN %04x\n",
901 				 tgt->bus_id, lu->lun);
902 			/* Let any waiting I/O fail from now on. */
903 			sbp2_unblock(lu->tgt);
904 		}
905 		goto out;
906 	}
907 
908 	tgt->node_id	  = node_id;
909 	tgt->address_high = local_node_id << 16;
910 	smp_wmb();	  /* node IDs must not be older than generation */
911 	lu->generation	  = generation;
912 
913 	lu->command_block_agent_address =
914 		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
915 		      << 32) | be32_to_cpu(response.command_block_agent.low);
916 	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
917 
918 	fw_notify("%s: logged in to LUN %04x (%d retries)\n",
919 		  tgt->bus_id, lu->lun, lu->retries);
920 
921 	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
922 	sbp2_set_busy_timeout(lu);
923 
924 	PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
925 	sbp2_agent_reset(lu);
926 
927 	/* This was a re-login. */
928 	if (lu->has_sdev) {
929 		sbp2_cancel_orbs(lu);
930 		sbp2_conditionally_unblock(lu);
931 		goto out;
932 	}
933 
934 	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
935 		ssleep(SBP2_INQUIRY_DELAY);
936 
937 	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
938 	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
939 	/*
940 	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
941 	 * Therefore __scsi_add_device() will get into trouble if a bus reset
942 	 * happens in parallel.  It will either fail or leave us with an
943 	 * unusable sdev.  As a workaround we check for this and retry the
944 	 * whole login and SCSI probing.
945 	 */
946 
947 	/* Reported error during __scsi_add_device() */
948 	if (IS_ERR(sdev))
949 		goto out_logout_login;
950 
951 	/* Unreported error during __scsi_add_device() */
952 	smp_rmb(); /* get current card generation */
953 	if (generation != device->card->generation) {
954 		scsi_remove_device(sdev);
955 		scsi_device_put(sdev);
956 		goto out_logout_login;
957 	}
958 
959 	/* No error during __scsi_add_device() */
960 	lu->has_sdev = true;
961 	scsi_device_put(sdev);
962 	sbp2_allow_block(lu);
963 	goto out;
964 
965  out_logout_login:
966 	smp_rmb(); /* generation may have changed */
967 	generation = device->generation;
968 	smp_rmb(); /* node_id must not be older than generation */
969 
970 	sbp2_send_management_orb(lu, device->node_id, generation,
971 				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
972 	/*
973 	 * If a bus reset happened, sbp2_update will have requeued
974 	 * lu->work already.  Reset the work from reconnect to login.
975 	 */
976 	PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
977  out:
978 	sbp2_target_put(tgt);
979 }
980 
981 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
982 {
983 	struct sbp2_logical_unit *lu;
984 
985 	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
986 	if (!lu)
987 		return -ENOMEM;
988 
989 	lu->address_handler.length           = 0x100;
990 	lu->address_handler.address_callback = sbp2_status_write;
991 	lu->address_handler.callback_data    = lu;
992 
993 	if (fw_core_add_address_handler(&lu->address_handler,
994 					&fw_high_memory_region) < 0) {
995 		kfree(lu);
996 		return -ENOMEM;
997 	}
998 
999 	lu->tgt      = tgt;
1000 	lu->lun      = lun_entry & 0xffff;
1001 	lu->login_id = INVALID_LOGIN_ID;
1002 	lu->retries  = 0;
1003 	lu->has_sdev = false;
1004 	lu->blocked  = false;
1005 	++tgt->dont_block;
1006 	INIT_LIST_HEAD(&lu->orb_list);
1007 	INIT_DELAYED_WORK(&lu->work, sbp2_login);
1008 
1009 	list_add_tail(&lu->link, &tgt->lu_list);
1010 	return 0;
1011 }
1012 
1013 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
1014 {
1015 	struct fw_csr_iterator ci;
1016 	int key, value;
1017 
1018 	fw_csr_iterator_init(&ci, directory);
1019 	while (fw_csr_iterator_next(&ci, &key, &value))
1020 		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1021 		    sbp2_add_logical_unit(tgt, value) < 0)
1022 			return -ENOMEM;
1023 	return 0;
1024 }
1025 
1026 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
1027 			      u32 *model, u32 *firmware_revision)
1028 {
1029 	struct fw_csr_iterator ci;
1030 	int key, value;
1031 	unsigned int timeout;
1032 
1033 	fw_csr_iterator_init(&ci, directory);
1034 	while (fw_csr_iterator_next(&ci, &key, &value)) {
1035 		switch (key) {
1036 
1037 		case CSR_DEPENDENT_INFO | CSR_OFFSET:
1038 			tgt->management_agent_address =
1039 					CSR_REGISTER_BASE + 4 * value;
1040 			break;
1041 
1042 		case CSR_DIRECTORY_ID:
1043 			tgt->directory_id = value;
1044 			break;
1045 
1046 		case CSR_MODEL:
1047 			*model = value;
1048 			break;
1049 
1050 		case SBP2_CSR_FIRMWARE_REVISION:
1051 			*firmware_revision = value;
1052 			break;
1053 
1054 		case SBP2_CSR_UNIT_CHARACTERISTICS:
1055 			/* the timeout value is stored in 500ms units */
1056 			timeout = ((unsigned int) value >> 8 & 0xff) * 500;
1057 			timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);
1058 			tgt->mgt_orb_timeout =
1059 				  min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);
1060 
1061 			if (timeout > tgt->mgt_orb_timeout)
1062 				fw_notify("%s: config rom contains %ds "
1063 					  "management ORB timeout, limiting "
1064 					  "to %ds\n", tgt->bus_id,
1065 					  timeout / 1000,
1066 					  tgt->mgt_orb_timeout / 1000);
1067 			break;
1068 
1069 		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1070 			if (sbp2_add_logical_unit(tgt, value) < 0)
1071 				return -ENOMEM;
1072 			break;
1073 
1074 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1075 			/* Adjust for the increment in the iterator */
1076 			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1077 				return -ENOMEM;
1078 			break;
1079 		}
1080 	}
1081 	return 0;
1082 }
1083 
1084 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1085 				  u32 firmware_revision)
1086 {
1087 	int i;
1088 	unsigned int w = sbp2_param_workarounds;
1089 
1090 	if (w)
1091 		fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1092 			  "if you need the workarounds parameter for %s\n",
1093 			  tgt->bus_id);
1094 
1095 	if (w & SBP2_WORKAROUND_OVERRIDE)
1096 		goto out;
1097 
1098 	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1099 
1100 		if (sbp2_workarounds_table[i].firmware_revision !=
1101 		    (firmware_revision & 0xffffff00))
1102 			continue;
1103 
1104 		if (sbp2_workarounds_table[i].model != model &&
1105 		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1106 			continue;
1107 
1108 		w |= sbp2_workarounds_table[i].workarounds;
1109 		break;
1110 	}
1111  out:
1112 	if (w)
1113 		fw_notify("Workarounds for %s: 0x%x "
1114 			  "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1115 			  tgt->bus_id, w, firmware_revision, model);
1116 	tgt->workarounds = w;
1117 }
1118 
1119 static struct scsi_host_template scsi_driver_template;
1120 
1121 static int sbp2_probe(struct device *dev)
1122 {
1123 	struct fw_unit *unit = fw_unit(dev);
1124 	struct fw_device *device = fw_parent_device(unit);
1125 	struct sbp2_target *tgt;
1126 	struct sbp2_logical_unit *lu;
1127 	struct Scsi_Host *shost;
1128 	u32 model, firmware_revision;
1129 
1130 	if (dma_get_max_seg_size(device->card->device) > SBP2_MAX_SEG_SIZE)
1131 		BUG_ON(dma_set_max_seg_size(device->card->device,
1132 					    SBP2_MAX_SEG_SIZE));
1133 
1134 	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1135 	if (shost == NULL)
1136 		return -ENOMEM;
1137 
1138 	tgt = (struct sbp2_target *)shost->hostdata;
1139 	dev_set_drvdata(&unit->device, tgt);
1140 	tgt->unit = unit;
1141 	kref_init(&tgt->kref);
1142 	INIT_LIST_HEAD(&tgt->lu_list);
1143 	tgt->bus_id = dev_name(&unit->device);
1144 	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1145 
1146 	if (fw_device_enable_phys_dma(device) < 0)
1147 		goto fail_shost_put;
1148 
1149 	if (scsi_add_host(shost, &unit->device) < 0)
1150 		goto fail_shost_put;
1151 
1152 	fw_device_get(device);
1153 	fw_unit_get(unit);
1154 
1155 	/* implicit directory ID */
1156 	tgt->directory_id = ((unit->directory - device->config_rom) * 4
1157 			     + CSR_CONFIG_ROM) & 0xffffff;
1158 
1159 	firmware_revision = SBP2_ROM_VALUE_MISSING;
1160 	model		  = SBP2_ROM_VALUE_MISSING;
1161 
1162 	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1163 			       &firmware_revision) < 0)
1164 		goto fail_tgt_put;
1165 
1166 	sbp2_init_workarounds(tgt, model, firmware_revision);
1167 
1168 	/*
1169 	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1170 	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
1171 	 * specifies the max payload size as 2 ^ (max_payload + 2), so
1172 	 * if we set this to max_speed + 7, we get the right value.
1173 	 */
1174 	tgt->max_payload = min(device->max_speed + 7, 10U);
1175 	tgt->max_payload = min(tgt->max_payload, device->card->max_receive - 1);
1176 
1177 	/* Do the login in a workqueue so we can easily reschedule retries. */
1178 	list_for_each_entry(lu, &tgt->lu_list, link)
1179 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1180 	return 0;
1181 
1182  fail_tgt_put:
1183 	sbp2_target_put(tgt);
1184 	return -ENOMEM;
1185 
1186  fail_shost_put:
1187 	scsi_host_put(shost);
1188 	return -ENOMEM;
1189 }
1190 
1191 static int sbp2_remove(struct device *dev)
1192 {
1193 	struct fw_unit *unit = fw_unit(dev);
1194 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1195 
1196 	sbp2_target_put(tgt);
1197 	return 0;
1198 }
1199 
1200 static void sbp2_reconnect(struct work_struct *work)
1201 {
1202 	struct sbp2_logical_unit *lu =
1203 		container_of(work, struct sbp2_logical_unit, work.work);
1204 	struct sbp2_target *tgt = lu->tgt;
1205 	struct fw_device *device = target_device(tgt);
1206 	int generation, node_id, local_node_id;
1207 
1208 	if (fw_device_is_shutdown(device))
1209 		goto out;
1210 
1211 	generation    = device->generation;
1212 	smp_rmb();    /* node IDs must not be older than generation */
1213 	node_id       = device->node_id;
1214 	local_node_id = device->card->node_id;
1215 
1216 	if (sbp2_send_management_orb(lu, node_id, generation,
1217 				     SBP2_RECONNECT_REQUEST,
1218 				     lu->login_id, NULL) < 0) {
1219 		/*
1220 		 * If reconnect was impossible even though we are in the
1221 		 * current generation, fall back and try to log in again.
1222 		 *
1223 		 * We could check for "Function rejected" status, but
1224 		 * looking at the bus generation as simpler and more general.
1225 		 */
1226 		smp_rmb(); /* get current card generation */
1227 		if (generation == device->card->generation ||
1228 		    lu->retries++ >= 5) {
1229 			fw_error("%s: failed to reconnect\n", tgt->bus_id);
1230 			lu->retries = 0;
1231 			PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1232 		}
1233 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1234 		goto out;
1235 	}
1236 
1237 	tgt->node_id      = node_id;
1238 	tgt->address_high = local_node_id << 16;
1239 	smp_wmb();	  /* node IDs must not be older than generation */
1240 	lu->generation	  = generation;
1241 
1242 	fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1243 		  tgt->bus_id, lu->lun, lu->retries);
1244 
1245 	sbp2_agent_reset(lu);
1246 	sbp2_cancel_orbs(lu);
1247 	sbp2_conditionally_unblock(lu);
1248  out:
1249 	sbp2_target_put(tgt);
1250 }
1251 
1252 static void sbp2_update(struct fw_unit *unit)
1253 {
1254 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1255 	struct sbp2_logical_unit *lu;
1256 
1257 	fw_device_enable_phys_dma(fw_parent_device(unit));
1258 
1259 	/*
1260 	 * Fw-core serializes sbp2_update() against sbp2_remove().
1261 	 * Iteration over tgt->lu_list is therefore safe here.
1262 	 */
1263 	list_for_each_entry(lu, &tgt->lu_list, link) {
1264 		sbp2_conditionally_block(lu);
1265 		lu->retries = 0;
1266 		sbp2_queue_work(lu, 0);
1267 	}
1268 }
1269 
1270 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
1271 #define SBP2_SW_VERSION_ENTRY	0x00010483
1272 
1273 static const struct ieee1394_device_id sbp2_id_table[] = {
1274 	{
1275 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1276 				IEEE1394_MATCH_VERSION,
1277 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1278 		.version      = SBP2_SW_VERSION_ENTRY,
1279 	},
1280 	{ }
1281 };
1282 
1283 static struct fw_driver sbp2_driver = {
1284 	.driver   = {
1285 		.owner  = THIS_MODULE,
1286 		.name   = sbp2_driver_name,
1287 		.bus    = &fw_bus_type,
1288 		.probe  = sbp2_probe,
1289 		.remove = sbp2_remove,
1290 	},
1291 	.update   = sbp2_update,
1292 	.id_table = sbp2_id_table,
1293 };
1294 
1295 static void sbp2_unmap_scatterlist(struct device *card_device,
1296 				   struct sbp2_command_orb *orb)
1297 {
1298 	if (scsi_sg_count(orb->cmd))
1299 		dma_unmap_sg(card_device, scsi_sglist(orb->cmd),
1300 			     scsi_sg_count(orb->cmd),
1301 			     orb->cmd->sc_data_direction);
1302 
1303 	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1304 		dma_unmap_single(card_device, orb->page_table_bus,
1305 				 sizeof(orb->page_table), DMA_TO_DEVICE);
1306 }
1307 
1308 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1309 {
1310 	int sam_status;
1311 
1312 	sense_data[0] = 0x70;
1313 	sense_data[1] = 0x0;
1314 	sense_data[2] = sbp2_status[1];
1315 	sense_data[3] = sbp2_status[4];
1316 	sense_data[4] = sbp2_status[5];
1317 	sense_data[5] = sbp2_status[6];
1318 	sense_data[6] = sbp2_status[7];
1319 	sense_data[7] = 10;
1320 	sense_data[8] = sbp2_status[8];
1321 	sense_data[9] = sbp2_status[9];
1322 	sense_data[10] = sbp2_status[10];
1323 	sense_data[11] = sbp2_status[11];
1324 	sense_data[12] = sbp2_status[2];
1325 	sense_data[13] = sbp2_status[3];
1326 	sense_data[14] = sbp2_status[12];
1327 	sense_data[15] = sbp2_status[13];
1328 
1329 	sam_status = sbp2_status[0] & 0x3f;
1330 
1331 	switch (sam_status) {
1332 	case SAM_STAT_GOOD:
1333 	case SAM_STAT_CHECK_CONDITION:
1334 	case SAM_STAT_CONDITION_MET:
1335 	case SAM_STAT_BUSY:
1336 	case SAM_STAT_RESERVATION_CONFLICT:
1337 	case SAM_STAT_COMMAND_TERMINATED:
1338 		return DID_OK << 16 | sam_status;
1339 
1340 	default:
1341 		return DID_ERROR << 16;
1342 	}
1343 }
1344 
1345 static void complete_command_orb(struct sbp2_orb *base_orb,
1346 				 struct sbp2_status *status)
1347 {
1348 	struct sbp2_command_orb *orb =
1349 		container_of(base_orb, struct sbp2_command_orb, base);
1350 	struct fw_device *device = target_device(orb->lu->tgt);
1351 	int result;
1352 
1353 	if (status != NULL) {
1354 		if (STATUS_GET_DEAD(*status))
1355 			sbp2_agent_reset_no_wait(orb->lu);
1356 
1357 		switch (STATUS_GET_RESPONSE(*status)) {
1358 		case SBP2_STATUS_REQUEST_COMPLETE:
1359 			result = DID_OK << 16;
1360 			break;
1361 		case SBP2_STATUS_TRANSPORT_FAILURE:
1362 			result = DID_BUS_BUSY << 16;
1363 			break;
1364 		case SBP2_STATUS_ILLEGAL_REQUEST:
1365 		case SBP2_STATUS_VENDOR_DEPENDENT:
1366 		default:
1367 			result = DID_ERROR << 16;
1368 			break;
1369 		}
1370 
1371 		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1372 			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1373 							   orb->cmd->sense_buffer);
1374 	} else {
1375 		/*
1376 		 * If the orb completes with status == NULL, something
1377 		 * went wrong, typically a bus reset happened mid-orb
1378 		 * or when sending the write (less likely).
1379 		 */
1380 		result = DID_BUS_BUSY << 16;
1381 		sbp2_conditionally_block(orb->lu);
1382 	}
1383 
1384 	dma_unmap_single(device->card->device, orb->base.request_bus,
1385 			 sizeof(orb->request), DMA_TO_DEVICE);
1386 	sbp2_unmap_scatterlist(device->card->device, orb);
1387 
1388 	orb->cmd->result = result;
1389 	orb->done(orb->cmd);
1390 }
1391 
1392 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1393 		struct fw_device *device, struct sbp2_logical_unit *lu)
1394 {
1395 	struct scatterlist *sg = scsi_sglist(orb->cmd);
1396 	int i, n;
1397 
1398 	n = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1399 		       orb->cmd->sc_data_direction);
1400 	if (n == 0)
1401 		goto fail;
1402 
1403 	/*
1404 	 * Handle the special case where there is only one element in
1405 	 * the scatter list by converting it to an immediate block
1406 	 * request. This is also a workaround for broken devices such
1407 	 * as the second generation iPod which doesn't support page
1408 	 * tables.
1409 	 */
1410 	if (n == 1) {
1411 		orb->request.data_descriptor.high =
1412 			cpu_to_be32(lu->tgt->address_high);
1413 		orb->request.data_descriptor.low  =
1414 			cpu_to_be32(sg_dma_address(sg));
1415 		orb->request.misc |=
1416 			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1417 		return 0;
1418 	}
1419 
1420 	for_each_sg(sg, sg, n, i) {
1421 		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1422 		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1423 	}
1424 
1425 	orb->page_table_bus =
1426 		dma_map_single(device->card->device, orb->page_table,
1427 			       sizeof(orb->page_table), DMA_TO_DEVICE);
1428 	if (dma_mapping_error(device->card->device, orb->page_table_bus))
1429 		goto fail_page_table;
1430 
1431 	/*
1432 	 * The data_descriptor pointer is the one case where we need
1433 	 * to fill in the node ID part of the address.  All other
1434 	 * pointers assume that the data referenced reside on the
1435 	 * initiator (i.e. us), but data_descriptor can refer to data
1436 	 * on other nodes so we need to put our ID in descriptor.high.
1437 	 */
1438 	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1439 	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1440 	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1441 					 COMMAND_ORB_DATA_SIZE(n));
1442 
1443 	return 0;
1444 
1445  fail_page_table:
1446 	dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1447 		     scsi_sg_count(orb->cmd), orb->cmd->sc_data_direction);
1448  fail:
1449 	return -ENOMEM;
1450 }
1451 
1452 /* SCSI stack integration */
1453 
1454 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1455 {
1456 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1457 	struct fw_device *device = target_device(lu->tgt);
1458 	struct sbp2_command_orb *orb;
1459 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1460 
1461 	/*
1462 	 * Bidirectional commands are not yet implemented, and unknown
1463 	 * transfer direction not handled.
1464 	 */
1465 	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1466 		fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1467 		cmd->result = DID_ERROR << 16;
1468 		done(cmd);
1469 		return 0;
1470 	}
1471 
1472 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1473 	if (orb == NULL) {
1474 		fw_notify("failed to alloc orb\n");
1475 		return SCSI_MLQUEUE_HOST_BUSY;
1476 	}
1477 
1478 	/* Initialize rcode to something not RCODE_COMPLETE. */
1479 	orb->base.rcode = -1;
1480 	kref_init(&orb->base.kref);
1481 
1482 	orb->lu   = lu;
1483 	orb->done = done;
1484 	orb->cmd  = cmd;
1485 
1486 	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1487 	orb->request.misc = cpu_to_be32(
1488 		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1489 		COMMAND_ORB_SPEED(device->max_speed) |
1490 		COMMAND_ORB_NOTIFY);
1491 
1492 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1493 		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1494 
1495 	generation = device->generation;
1496 	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1497 
1498 	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1499 		goto out;
1500 
1501 	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1502 
1503 	orb->base.callback = complete_command_orb;
1504 	orb->base.request_bus =
1505 		dma_map_single(device->card->device, &orb->request,
1506 			       sizeof(orb->request), DMA_TO_DEVICE);
1507 	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1508 		sbp2_unmap_scatterlist(device->card->device, orb);
1509 		goto out;
1510 	}
1511 
1512 	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1513 		      lu->command_block_agent_address + SBP2_ORB_POINTER);
1514 	retval = 0;
1515  out:
1516 	kref_put(&orb->base.kref, free_orb);
1517 	return retval;
1518 }
1519 
1520 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1521 {
1522 	struct sbp2_logical_unit *lu = sdev->hostdata;
1523 
1524 	/* (Re-)Adding logical units via the SCSI stack is not supported. */
1525 	if (!lu)
1526 		return -ENOSYS;
1527 
1528 	sdev->allow_restart = 1;
1529 
1530 	/* SBP-2 requires quadlet alignment of the data buffers. */
1531 	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1532 
1533 	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1534 		sdev->inquiry_len = 36;
1535 
1536 	return 0;
1537 }
1538 
1539 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1540 {
1541 	struct sbp2_logical_unit *lu = sdev->hostdata;
1542 
1543 	sdev->use_10_for_rw = 1;
1544 
1545 	if (sbp2_param_exclusive_login)
1546 		sdev->manage_start_stop = 1;
1547 
1548 	if (sdev->type == TYPE_ROM)
1549 		sdev->use_10_for_ms = 1;
1550 
1551 	if (sdev->type == TYPE_DISK &&
1552 	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1553 		sdev->skip_ms_page_8 = 1;
1554 
1555 	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1556 		sdev->fix_capacity = 1;
1557 
1558 	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1559 		sdev->start_stop_pwr_cond = 1;
1560 
1561 	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1562 		blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
1563 
1564 	blk_queue_max_segment_size(sdev->request_queue, SBP2_MAX_SEG_SIZE);
1565 
1566 	return 0;
1567 }
1568 
1569 /*
1570  * Called by scsi stack when something has really gone wrong.  Usually
1571  * called when a command has timed-out for some reason.
1572  */
1573 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1574 {
1575 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1576 
1577 	fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1578 	sbp2_agent_reset(lu);
1579 	sbp2_cancel_orbs(lu);
1580 
1581 	return SUCCESS;
1582 }
1583 
1584 /*
1585  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1586  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1587  *
1588  * This is the concatenation of target port identifier and logical unit
1589  * identifier as per SAM-2...SAM-4 annex A.
1590  */
1591 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1592 			struct device_attribute *attr, char *buf)
1593 {
1594 	struct scsi_device *sdev = to_scsi_device(dev);
1595 	struct sbp2_logical_unit *lu;
1596 
1597 	if (!sdev)
1598 		return 0;
1599 
1600 	lu = sdev->hostdata;
1601 
1602 	return sprintf(buf, "%016llx:%06x:%04x\n",
1603 			(unsigned long long)lu->tgt->guid,
1604 			lu->tgt->directory_id, lu->lun);
1605 }
1606 
1607 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1608 
1609 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1610 	&dev_attr_ieee1394_id,
1611 	NULL
1612 };
1613 
1614 static struct scsi_host_template scsi_driver_template = {
1615 	.module			= THIS_MODULE,
1616 	.name			= "SBP-2 IEEE-1394",
1617 	.proc_name		= sbp2_driver_name,
1618 	.queuecommand		= sbp2_scsi_queuecommand,
1619 	.slave_alloc		= sbp2_scsi_slave_alloc,
1620 	.slave_configure	= sbp2_scsi_slave_configure,
1621 	.eh_abort_handler	= sbp2_scsi_abort,
1622 	.this_id		= -1,
1623 	.sg_tablesize		= SG_ALL,
1624 	.use_clustering		= ENABLE_CLUSTERING,
1625 	.cmd_per_lun		= 1,
1626 	.can_queue		= 1,
1627 	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
1628 };
1629 
1630 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1631 MODULE_DESCRIPTION("SCSI over IEEE1394");
1632 MODULE_LICENSE("GPL");
1633 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1634 
1635 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1636 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1637 MODULE_ALIAS("sbp2");
1638 #endif
1639 
1640 static int __init sbp2_init(void)
1641 {
1642 	sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1643 	if (!sbp2_wq)
1644 		return -ENOMEM;
1645 
1646 	return driver_register(&sbp2_driver.driver);
1647 }
1648 
1649 static void __exit sbp2_cleanup(void)
1650 {
1651 	driver_unregister(&sbp2_driver.driver);
1652 	destroy_workqueue(sbp2_wq);
1653 }
1654 
1655 module_init(sbp2_init);
1656 module_exit(sbp2_cleanup);
1657