xref: /linux/drivers/firewire/sbp2.c (revision dfc349402de8e95f6a42e8341e9ea193b718eee3)
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 #define SBP2_ORB_TIMEOUT		2000U		/* Timeout in ms */
192 #define SBP2_ORB_NULL			0x80000000
193 #define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
194 #define SBP2_CYCLE_LIMIT		(0xc8 << 12)	/* 200 125us cycles */
195 
196 /*
197  * There is no transport protocol limit to the CDB length,  but we implement
198  * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
199  */
200 #define SBP2_MAX_CDB_SIZE		16
201 
202 /*
203  * The default maximum s/g segment size of a FireWire controller is
204  * usually 0x10000, but SBP-2 only allows 0xffff. Since buffers have to
205  * be quadlet-aligned, we set the length limit to 0xffff & ~3.
206  */
207 #define SBP2_MAX_SEG_SIZE		0xfffc
208 
209 /* Unit directory keys */
210 #define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
211 #define SBP2_CSR_FIRMWARE_REVISION	0x3c
212 #define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
213 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4
214 
215 /* Management orb opcodes */
216 #define SBP2_LOGIN_REQUEST		0x0
217 #define SBP2_QUERY_LOGINS_REQUEST	0x1
218 #define SBP2_RECONNECT_REQUEST		0x3
219 #define SBP2_SET_PASSWORD_REQUEST	0x4
220 #define SBP2_LOGOUT_REQUEST		0x7
221 #define SBP2_ABORT_TASK_REQUEST		0xb
222 #define SBP2_ABORT_TASK_SET		0xc
223 #define SBP2_LOGICAL_UNIT_RESET		0xe
224 #define SBP2_TARGET_RESET_REQUEST	0xf
225 
226 /* Offsets for command block agent registers */
227 #define SBP2_AGENT_STATE		0x00
228 #define SBP2_AGENT_RESET		0x04
229 #define SBP2_ORB_POINTER		0x08
230 #define SBP2_DOORBELL			0x10
231 #define SBP2_UNSOLICITED_STATUS_ENABLE	0x14
232 
233 /* Status write response codes */
234 #define SBP2_STATUS_REQUEST_COMPLETE	0x0
235 #define SBP2_STATUS_TRANSPORT_FAILURE	0x1
236 #define SBP2_STATUS_ILLEGAL_REQUEST	0x2
237 #define SBP2_STATUS_VENDOR_DEPENDENT	0x3
238 
239 #define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
240 #define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
241 #define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
242 #define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
243 #define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
244 #define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
245 #define STATUS_GET_ORB_LOW(v)		((v).orb_low)
246 #define STATUS_GET_DATA(v)		((v).data)
247 
248 struct sbp2_status {
249 	u32 status;
250 	u32 orb_low;
251 	u8 data[24];
252 };
253 
254 struct sbp2_pointer {
255 	__be32 high;
256 	__be32 low;
257 };
258 
259 struct sbp2_orb {
260 	struct fw_transaction t;
261 	struct kref kref;
262 	dma_addr_t request_bus;
263 	int rcode;
264 	struct sbp2_pointer pointer;
265 	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
266 	struct list_head link;
267 };
268 
269 #define MANAGEMENT_ORB_LUN(v)			((v))
270 #define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
271 #define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
272 #define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
273 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
274 #define MANAGEMENT_ORB_NOTIFY			((1) << 31)
275 
276 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
277 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
278 
279 struct sbp2_management_orb {
280 	struct sbp2_orb base;
281 	struct {
282 		struct sbp2_pointer password;
283 		struct sbp2_pointer response;
284 		__be32 misc;
285 		__be32 length;
286 		struct sbp2_pointer status_fifo;
287 	} request;
288 	__be32 response[4];
289 	dma_addr_t response_bus;
290 	struct completion done;
291 	struct sbp2_status status;
292 };
293 
294 struct sbp2_login_response {
295 	__be32 misc;
296 	struct sbp2_pointer command_block_agent;
297 	__be32 reconnect_hold;
298 };
299 #define COMMAND_ORB_DATA_SIZE(v)	((v))
300 #define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
301 #define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
302 #define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
303 #define COMMAND_ORB_SPEED(v)		((v) << 24)
304 #define COMMAND_ORB_DIRECTION		((1) << 27)
305 #define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
306 #define COMMAND_ORB_NOTIFY		((1) << 31)
307 
308 struct sbp2_command_orb {
309 	struct sbp2_orb base;
310 	struct {
311 		struct sbp2_pointer next;
312 		struct sbp2_pointer data_descriptor;
313 		__be32 misc;
314 		u8 command_block[SBP2_MAX_CDB_SIZE];
315 	} request;
316 	struct scsi_cmnd *cmd;
317 	scsi_done_fn_t done;
318 	struct sbp2_logical_unit *lu;
319 
320 	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
321 	dma_addr_t page_table_bus;
322 };
323 
324 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
325 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
326 
327 /*
328  * List of devices with known bugs.
329  *
330  * The firmware_revision field, masked with 0xffff00, is the best
331  * indicator for the type of bridge chip of a device.  It yields a few
332  * false positives but this did not break correctly behaving devices
333  * so far.
334  */
335 static const struct {
336 	u32 firmware_revision;
337 	u32 model;
338 	unsigned int workarounds;
339 } sbp2_workarounds_table[] = {
340 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
341 		.firmware_revision	= 0x002800,
342 		.model			= 0x001010,
343 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
344 					  SBP2_WORKAROUND_MODE_SENSE_8 |
345 					  SBP2_WORKAROUND_POWER_CONDITION,
346 	},
347 	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
348 		.firmware_revision	= 0x002800,
349 		.model			= 0x000000,
350 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
351 	},
352 	/* Initio bridges, actually only needed for some older ones */ {
353 		.firmware_revision	= 0x000200,
354 		.model			= SBP2_ROM_VALUE_WILDCARD,
355 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
356 	},
357 	/* PL-3507 bridge with Prolific firmware */ {
358 		.firmware_revision	= 0x012800,
359 		.model			= SBP2_ROM_VALUE_WILDCARD,
360 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
361 	},
362 	/* Symbios bridge */ {
363 		.firmware_revision	= 0xa0b800,
364 		.model			= SBP2_ROM_VALUE_WILDCARD,
365 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
366 	},
367 	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
368 		.firmware_revision	= 0x002600,
369 		.model			= SBP2_ROM_VALUE_WILDCARD,
370 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
371 	},
372 	/*
373 	 * iPod 2nd generation: needs 128k max transfer size workaround
374 	 * iPod 3rd generation: needs fix capacity workaround
375 	 */
376 	{
377 		.firmware_revision	= 0x0a2700,
378 		.model			= 0x000000,
379 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
380 					  SBP2_WORKAROUND_FIX_CAPACITY,
381 	},
382 	/* iPod 4th generation */ {
383 		.firmware_revision	= 0x0a2700,
384 		.model			= 0x000021,
385 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
386 	},
387 	/* iPod mini */ {
388 		.firmware_revision	= 0x0a2700,
389 		.model			= 0x000022,
390 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
391 	},
392 	/* iPod mini */ {
393 		.firmware_revision	= 0x0a2700,
394 		.model			= 0x000023,
395 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
396 	},
397 	/* iPod Photo */ {
398 		.firmware_revision	= 0x0a2700,
399 		.model			= 0x00007e,
400 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
401 	}
402 };
403 
404 static void free_orb(struct kref *kref)
405 {
406 	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
407 
408 	kfree(orb);
409 }
410 
411 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
412 			      int tcode, int destination, int source,
413 			      int generation, int speed,
414 			      unsigned long long offset,
415 			      void *payload, size_t length, void *callback_data)
416 {
417 	struct sbp2_logical_unit *lu = callback_data;
418 	struct sbp2_orb *orb;
419 	struct sbp2_status status;
420 	unsigned long flags;
421 
422 	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
423 	    length < 8 || length > sizeof(status)) {
424 		fw_send_response(card, request, RCODE_TYPE_ERROR);
425 		return;
426 	}
427 
428 	status.status  = be32_to_cpup(payload);
429 	status.orb_low = be32_to_cpup(payload + 4);
430 	memset(status.data, 0, sizeof(status.data));
431 	if (length > 8)
432 		memcpy(status.data, payload + 8, length - 8);
433 
434 	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
435 		fw_notify("non-orb related status write, not handled\n");
436 		fw_send_response(card, request, RCODE_COMPLETE);
437 		return;
438 	}
439 
440 	/* Lookup the orb corresponding to this status write. */
441 	spin_lock_irqsave(&card->lock, flags);
442 	list_for_each_entry(orb, &lu->orb_list, link) {
443 		if (STATUS_GET_ORB_HIGH(status) == 0 &&
444 		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
445 			orb->rcode = RCODE_COMPLETE;
446 			list_del(&orb->link);
447 			break;
448 		}
449 	}
450 	spin_unlock_irqrestore(&card->lock, flags);
451 
452 	if (&orb->link != &lu->orb_list) {
453 		orb->callback(orb, &status);
454 		kref_put(&orb->kref, free_orb);
455 	} else {
456 		fw_error("status write for unknown orb\n");
457 	}
458 
459 	fw_send_response(card, request, RCODE_COMPLETE);
460 }
461 
462 static void complete_transaction(struct fw_card *card, int rcode,
463 				 void *payload, size_t length, void *data)
464 {
465 	struct sbp2_orb *orb = data;
466 	unsigned long flags;
467 
468 	/*
469 	 * This is a little tricky.  We can get the status write for
470 	 * the orb before we get this callback.  The status write
471 	 * handler above will assume the orb pointer transaction was
472 	 * successful and set the rcode to RCODE_COMPLETE for the orb.
473 	 * So this callback only sets the rcode if it hasn't already
474 	 * been set and only does the cleanup if the transaction
475 	 * failed and we didn't already get a status write.
476 	 */
477 	spin_lock_irqsave(&card->lock, flags);
478 
479 	if (orb->rcode == -1)
480 		orb->rcode = rcode;
481 	if (orb->rcode != RCODE_COMPLETE) {
482 		list_del(&orb->link);
483 		spin_unlock_irqrestore(&card->lock, flags);
484 		orb->callback(orb, NULL);
485 	} else {
486 		spin_unlock_irqrestore(&card->lock, flags);
487 	}
488 
489 	kref_put(&orb->kref, free_orb);
490 }
491 
492 static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
493 			  int node_id, int generation, u64 offset)
494 {
495 	struct fw_device *device = target_device(lu->tgt);
496 	unsigned long flags;
497 
498 	orb->pointer.high = 0;
499 	orb->pointer.low = cpu_to_be32(orb->request_bus);
500 
501 	spin_lock_irqsave(&device->card->lock, flags);
502 	list_add_tail(&orb->link, &lu->orb_list);
503 	spin_unlock_irqrestore(&device->card->lock, flags);
504 
505 	/* Take a ref for the orb list and for the transaction callback. */
506 	kref_get(&orb->kref);
507 	kref_get(&orb->kref);
508 
509 	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
510 			node_id, generation, device->max_speed, offset,
511 			&orb->pointer, sizeof(orb->pointer),
512 			complete_transaction, orb);
513 }
514 
515 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
516 {
517 	struct fw_device *device = target_device(lu->tgt);
518 	struct sbp2_orb *orb, *next;
519 	struct list_head list;
520 	unsigned long flags;
521 	int retval = -ENOENT;
522 
523 	INIT_LIST_HEAD(&list);
524 	spin_lock_irqsave(&device->card->lock, flags);
525 	list_splice_init(&lu->orb_list, &list);
526 	spin_unlock_irqrestore(&device->card->lock, flags);
527 
528 	list_for_each_entry_safe(orb, next, &list, link) {
529 		retval = 0;
530 		if (fw_cancel_transaction(device->card, &orb->t) == 0)
531 			continue;
532 
533 		orb->rcode = RCODE_CANCELLED;
534 		orb->callback(orb, NULL);
535 	}
536 
537 	return retval;
538 }
539 
540 static void complete_management_orb(struct sbp2_orb *base_orb,
541 				    struct sbp2_status *status)
542 {
543 	struct sbp2_management_orb *orb =
544 		container_of(base_orb, struct sbp2_management_orb, base);
545 
546 	if (status)
547 		memcpy(&orb->status, status, sizeof(*status));
548 	complete(&orb->done);
549 }
550 
551 static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
552 				    int generation, int function,
553 				    int lun_or_login_id, void *response)
554 {
555 	struct fw_device *device = target_device(lu->tgt);
556 	struct sbp2_management_orb *orb;
557 	unsigned int timeout;
558 	int retval = -ENOMEM;
559 
560 	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
561 		return 0;
562 
563 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
564 	if (orb == NULL)
565 		return -ENOMEM;
566 
567 	kref_init(&orb->base.kref);
568 	orb->response_bus =
569 		dma_map_single(device->card->device, &orb->response,
570 			       sizeof(orb->response), DMA_FROM_DEVICE);
571 	if (dma_mapping_error(device->card->device, orb->response_bus))
572 		goto fail_mapping_response;
573 
574 	orb->request.response.high = 0;
575 	orb->request.response.low  = cpu_to_be32(orb->response_bus);
576 
577 	orb->request.misc = cpu_to_be32(
578 		MANAGEMENT_ORB_NOTIFY |
579 		MANAGEMENT_ORB_FUNCTION(function) |
580 		MANAGEMENT_ORB_LUN(lun_or_login_id));
581 	orb->request.length = cpu_to_be32(
582 		MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
583 
584 	orb->request.status_fifo.high =
585 		cpu_to_be32(lu->address_handler.offset >> 32);
586 	orb->request.status_fifo.low  =
587 		cpu_to_be32(lu->address_handler.offset);
588 
589 	if (function == SBP2_LOGIN_REQUEST) {
590 		/* Ask for 2^2 == 4 seconds reconnect grace period */
591 		orb->request.misc |= cpu_to_be32(
592 			MANAGEMENT_ORB_RECONNECT(2) |
593 			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
594 		timeout = lu->tgt->mgt_orb_timeout;
595 	} else {
596 		timeout = SBP2_ORB_TIMEOUT;
597 	}
598 
599 	init_completion(&orb->done);
600 	orb->base.callback = complete_management_orb;
601 
602 	orb->base.request_bus =
603 		dma_map_single(device->card->device, &orb->request,
604 			       sizeof(orb->request), DMA_TO_DEVICE);
605 	if (dma_mapping_error(device->card->device, orb->base.request_bus))
606 		goto fail_mapping_request;
607 
608 	sbp2_send_orb(&orb->base, lu, node_id, generation,
609 		      lu->tgt->management_agent_address);
610 
611 	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
612 
613 	retval = -EIO;
614 	if (sbp2_cancel_orbs(lu) == 0) {
615 		fw_error("%s: orb reply timed out, rcode=0x%02x\n",
616 			 lu->tgt->bus_id, orb->base.rcode);
617 		goto out;
618 	}
619 
620 	if (orb->base.rcode != RCODE_COMPLETE) {
621 		fw_error("%s: management write failed, rcode 0x%02x\n",
622 			 lu->tgt->bus_id, orb->base.rcode);
623 		goto out;
624 	}
625 
626 	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
627 	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
628 		fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
629 			 STATUS_GET_RESPONSE(orb->status),
630 			 STATUS_GET_SBP_STATUS(orb->status));
631 		goto out;
632 	}
633 
634 	retval = 0;
635  out:
636 	dma_unmap_single(device->card->device, orb->base.request_bus,
637 			 sizeof(orb->request), DMA_TO_DEVICE);
638  fail_mapping_request:
639 	dma_unmap_single(device->card->device, orb->response_bus,
640 			 sizeof(orb->response), DMA_FROM_DEVICE);
641  fail_mapping_response:
642 	if (response)
643 		memcpy(response, orb->response, sizeof(orb->response));
644 	kref_put(&orb->base.kref, free_orb);
645 
646 	return retval;
647 }
648 
649 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
650 {
651 	struct fw_device *device = target_device(lu->tgt);
652 	__be32 d = 0;
653 
654 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
655 			   lu->tgt->node_id, lu->generation, device->max_speed,
656 			   lu->command_block_agent_address + SBP2_AGENT_RESET,
657 			   &d, sizeof(d));
658 }
659 
660 static void complete_agent_reset_write_no_wait(struct fw_card *card,
661 		int rcode, void *payload, size_t length, void *data)
662 {
663 	kfree(data);
664 }
665 
666 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
667 {
668 	struct fw_device *device = target_device(lu->tgt);
669 	struct fw_transaction *t;
670 	static __be32 d;
671 
672 	t = kmalloc(sizeof(*t), GFP_ATOMIC);
673 	if (t == NULL)
674 		return;
675 
676 	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
677 			lu->tgt->node_id, lu->generation, device->max_speed,
678 			lu->command_block_agent_address + SBP2_AGENT_RESET,
679 			&d, sizeof(d), complete_agent_reset_write_no_wait, t);
680 }
681 
682 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
683 {
684 	/*
685 	 * We may access dont_block without taking card->lock here:
686 	 * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
687 	 * are currently serialized against each other.
688 	 * And a wrong result in sbp2_conditionally_block()'s access of
689 	 * dont_block is rather harmless, it simply misses its first chance.
690 	 */
691 	--lu->tgt->dont_block;
692 }
693 
694 /*
695  * Blocks lu->tgt if all of the following conditions are met:
696  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
697  *     logical units have been finished (indicated by dont_block == 0).
698  *   - lu->generation is stale.
699  *
700  * Note, scsi_block_requests() must be called while holding card->lock,
701  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
702  * unblock the target.
703  */
704 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
705 {
706 	struct sbp2_target *tgt = lu->tgt;
707 	struct fw_card *card = target_device(tgt)->card;
708 	struct Scsi_Host *shost =
709 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
710 	unsigned long flags;
711 
712 	spin_lock_irqsave(&card->lock, flags);
713 	if (!tgt->dont_block && !lu->blocked &&
714 	    lu->generation != card->generation) {
715 		lu->blocked = true;
716 		if (++tgt->blocked == 1)
717 			scsi_block_requests(shost);
718 	}
719 	spin_unlock_irqrestore(&card->lock, flags);
720 }
721 
722 /*
723  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
724  * Note, it is harmless to run scsi_unblock_requests() outside the
725  * card->lock protected section.  On the other hand, running it inside
726  * the section might clash with shost->host_lock.
727  */
728 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
729 {
730 	struct sbp2_target *tgt = lu->tgt;
731 	struct fw_card *card = target_device(tgt)->card;
732 	struct Scsi_Host *shost =
733 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
734 	unsigned long flags;
735 	bool unblock = false;
736 
737 	spin_lock_irqsave(&card->lock, flags);
738 	if (lu->blocked && lu->generation == card->generation) {
739 		lu->blocked = false;
740 		unblock = --tgt->blocked == 0;
741 	}
742 	spin_unlock_irqrestore(&card->lock, flags);
743 
744 	if (unblock)
745 		scsi_unblock_requests(shost);
746 }
747 
748 /*
749  * Prevents future blocking of tgt and unblocks it.
750  * Note, it is harmless to run scsi_unblock_requests() outside the
751  * card->lock protected section.  On the other hand, running it inside
752  * the section might clash with shost->host_lock.
753  */
754 static void sbp2_unblock(struct sbp2_target *tgt)
755 {
756 	struct fw_card *card = target_device(tgt)->card;
757 	struct Scsi_Host *shost =
758 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
759 	unsigned long flags;
760 
761 	spin_lock_irqsave(&card->lock, flags);
762 	++tgt->dont_block;
763 	spin_unlock_irqrestore(&card->lock, flags);
764 
765 	scsi_unblock_requests(shost);
766 }
767 
768 static int sbp2_lun2int(u16 lun)
769 {
770 	struct scsi_lun eight_bytes_lun;
771 
772 	memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
773 	eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
774 	eight_bytes_lun.scsi_lun[1] = lun & 0xff;
775 
776 	return scsilun_to_int(&eight_bytes_lun);
777 }
778 
779 static void sbp2_release_target(struct kref *kref)
780 {
781 	struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
782 	struct sbp2_logical_unit *lu, *next;
783 	struct Scsi_Host *shost =
784 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
785 	struct scsi_device *sdev;
786 	struct fw_device *device = target_device(tgt);
787 
788 	/* prevent deadlocks */
789 	sbp2_unblock(tgt);
790 
791 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
792 		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
793 		if (sdev) {
794 			scsi_remove_device(sdev);
795 			scsi_device_put(sdev);
796 		}
797 		if (lu->login_id != INVALID_LOGIN_ID) {
798 			int generation, node_id;
799 			/*
800 			 * tgt->node_id may be obsolete here if we failed
801 			 * during initial login or after a bus reset where
802 			 * the topology changed.
803 			 */
804 			generation = device->generation;
805 			smp_rmb(); /* node_id vs. generation */
806 			node_id    = device->node_id;
807 			sbp2_send_management_orb(lu, node_id, generation,
808 						 SBP2_LOGOUT_REQUEST,
809 						 lu->login_id, NULL);
810 		}
811 		fw_core_remove_address_handler(&lu->address_handler);
812 		list_del(&lu->link);
813 		kfree(lu);
814 	}
815 	scsi_remove_host(shost);
816 	fw_notify("released %s, target %d:0:0\n", tgt->bus_id, shost->host_no);
817 
818 	fw_unit_put(tgt->unit);
819 	scsi_host_put(shost);
820 	fw_device_put(device);
821 }
822 
823 static struct workqueue_struct *sbp2_wq;
824 
825 static void sbp2_target_put(struct sbp2_target *tgt)
826 {
827 	kref_put(&tgt->kref, sbp2_release_target);
828 }
829 
830 /*
831  * Always get the target's kref when scheduling work on one its units.
832  * Each workqueue job is responsible to call sbp2_target_put() upon return.
833  */
834 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
835 {
836 	kref_get(&lu->tgt->kref);
837 	if (!queue_delayed_work(sbp2_wq, &lu->work, delay))
838 		sbp2_target_put(lu->tgt);
839 }
840 
841 /*
842  * Write retransmit retry values into the BUSY_TIMEOUT register.
843  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
844  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
845  *   saner value after logging into the device.
846  * - The dual-phase retry protocol is optional to implement, and if not
847  *   supported, writes to the dual-phase portion of the register will be
848  *   ignored. We try to write the original 1394-1995 default here.
849  * - In the case of devices that are also SBP-3-compliant, all writes are
850  *   ignored, as the register is read-only, but contains single-phase retry of
851  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
852  *   write attempt is safe and yields more consistent behavior for all devices.
853  *
854  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
855  * and section 6.4 of the SBP-3 spec for further details.
856  */
857 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
858 {
859 	struct fw_device *device = target_device(lu->tgt);
860 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
861 
862 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
863 			   lu->tgt->node_id, lu->generation, device->max_speed,
864 			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT,
865 			   &d, sizeof(d));
866 }
867 
868 static void sbp2_reconnect(struct work_struct *work);
869 
870 static void sbp2_login(struct work_struct *work)
871 {
872 	struct sbp2_logical_unit *lu =
873 		container_of(work, struct sbp2_logical_unit, work.work);
874 	struct sbp2_target *tgt = lu->tgt;
875 	struct fw_device *device = target_device(tgt);
876 	struct Scsi_Host *shost;
877 	struct scsi_device *sdev;
878 	struct sbp2_login_response response;
879 	int generation, node_id, local_node_id;
880 
881 	if (fw_device_is_shutdown(device))
882 		goto out;
883 
884 	generation    = device->generation;
885 	smp_rmb();    /* node IDs must not be older than generation */
886 	node_id       = device->node_id;
887 	local_node_id = device->card->node_id;
888 
889 	/* If this is a re-login attempt, log out, or we might be rejected. */
890 	if (lu->has_sdev)
891 		sbp2_send_management_orb(lu, device->node_id, generation,
892 				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
893 
894 	if (sbp2_send_management_orb(lu, node_id, generation,
895 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
896 		if (lu->retries++ < 5) {
897 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
898 		} else {
899 			fw_error("%s: failed to login to LUN %04x\n",
900 				 tgt->bus_id, lu->lun);
901 			/* Let any waiting I/O fail from now on. */
902 			sbp2_unblock(lu->tgt);
903 		}
904 		goto out;
905 	}
906 
907 	tgt->node_id	  = node_id;
908 	tgt->address_high = local_node_id << 16;
909 	smp_wmb();	  /* node IDs must not be older than generation */
910 	lu->generation	  = generation;
911 
912 	lu->command_block_agent_address =
913 		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
914 		      << 32) | be32_to_cpu(response.command_block_agent.low);
915 	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
916 
917 	fw_notify("%s: logged in to LUN %04x (%d retries)\n",
918 		  tgt->bus_id, lu->lun, lu->retries);
919 
920 	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
921 	sbp2_set_busy_timeout(lu);
922 
923 	PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
924 	sbp2_agent_reset(lu);
925 
926 	/* This was a re-login. */
927 	if (lu->has_sdev) {
928 		sbp2_cancel_orbs(lu);
929 		sbp2_conditionally_unblock(lu);
930 		goto out;
931 	}
932 
933 	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
934 		ssleep(SBP2_INQUIRY_DELAY);
935 
936 	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
937 	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
938 	/*
939 	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
940 	 * Therefore __scsi_add_device() will get into trouble if a bus reset
941 	 * happens in parallel.  It will either fail or leave us with an
942 	 * unusable sdev.  As a workaround we check for this and retry the
943 	 * whole login and SCSI probing.
944 	 */
945 
946 	/* Reported error during __scsi_add_device() */
947 	if (IS_ERR(sdev))
948 		goto out_logout_login;
949 
950 	/* Unreported error during __scsi_add_device() */
951 	smp_rmb(); /* get current card generation */
952 	if (generation != device->card->generation) {
953 		scsi_remove_device(sdev);
954 		scsi_device_put(sdev);
955 		goto out_logout_login;
956 	}
957 
958 	/* No error during __scsi_add_device() */
959 	lu->has_sdev = true;
960 	scsi_device_put(sdev);
961 	sbp2_allow_block(lu);
962 	goto out;
963 
964  out_logout_login:
965 	smp_rmb(); /* generation may have changed */
966 	generation = device->generation;
967 	smp_rmb(); /* node_id must not be older than generation */
968 
969 	sbp2_send_management_orb(lu, device->node_id, generation,
970 				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
971 	/*
972 	 * If a bus reset happened, sbp2_update will have requeued
973 	 * lu->work already.  Reset the work from reconnect to login.
974 	 */
975 	PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
976  out:
977 	sbp2_target_put(tgt);
978 }
979 
980 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
981 {
982 	struct sbp2_logical_unit *lu;
983 
984 	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
985 	if (!lu)
986 		return -ENOMEM;
987 
988 	lu->address_handler.length           = 0x100;
989 	lu->address_handler.address_callback = sbp2_status_write;
990 	lu->address_handler.callback_data    = lu;
991 
992 	if (fw_core_add_address_handler(&lu->address_handler,
993 					&fw_high_memory_region) < 0) {
994 		kfree(lu);
995 		return -ENOMEM;
996 	}
997 
998 	lu->tgt      = tgt;
999 	lu->lun      = lun_entry & 0xffff;
1000 	lu->login_id = INVALID_LOGIN_ID;
1001 	lu->retries  = 0;
1002 	lu->has_sdev = false;
1003 	lu->blocked  = false;
1004 	++tgt->dont_block;
1005 	INIT_LIST_HEAD(&lu->orb_list);
1006 	INIT_DELAYED_WORK(&lu->work, sbp2_login);
1007 
1008 	list_add_tail(&lu->link, &tgt->lu_list);
1009 	return 0;
1010 }
1011 
1012 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
1013 {
1014 	struct fw_csr_iterator ci;
1015 	int key, value;
1016 
1017 	fw_csr_iterator_init(&ci, directory);
1018 	while (fw_csr_iterator_next(&ci, &key, &value))
1019 		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1020 		    sbp2_add_logical_unit(tgt, value) < 0)
1021 			return -ENOMEM;
1022 	return 0;
1023 }
1024 
1025 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
1026 			      u32 *model, u32 *firmware_revision)
1027 {
1028 	struct fw_csr_iterator ci;
1029 	int key, value;
1030 
1031 	fw_csr_iterator_init(&ci, directory);
1032 	while (fw_csr_iterator_next(&ci, &key, &value)) {
1033 		switch (key) {
1034 
1035 		case CSR_DEPENDENT_INFO | CSR_OFFSET:
1036 			tgt->management_agent_address =
1037 					CSR_REGISTER_BASE + 4 * value;
1038 			break;
1039 
1040 		case CSR_DIRECTORY_ID:
1041 			tgt->directory_id = value;
1042 			break;
1043 
1044 		case CSR_MODEL:
1045 			*model = value;
1046 			break;
1047 
1048 		case SBP2_CSR_FIRMWARE_REVISION:
1049 			*firmware_revision = value;
1050 			break;
1051 
1052 		case SBP2_CSR_UNIT_CHARACTERISTICS:
1053 			/* the timeout value is stored in 500ms units */
1054 			tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
1055 			break;
1056 
1057 		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1058 			if (sbp2_add_logical_unit(tgt, value) < 0)
1059 				return -ENOMEM;
1060 			break;
1061 
1062 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1063 			/* Adjust for the increment in the iterator */
1064 			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1065 				return -ENOMEM;
1066 			break;
1067 		}
1068 	}
1069 	return 0;
1070 }
1071 
1072 /*
1073  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
1074  * provided in the config rom. Most devices do provide a value, which
1075  * we'll use for login management orbs, but with some sane limits.
1076  */
1077 static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
1078 {
1079 	unsigned int timeout = tgt->mgt_orb_timeout;
1080 
1081 	if (timeout > 40000)
1082 		fw_notify("%s: %ds mgt_ORB_timeout limited to 40s\n",
1083 			  tgt->bus_id, timeout / 1000);
1084 
1085 	tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
1086 }
1087 
1088 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1089 				  u32 firmware_revision)
1090 {
1091 	int i;
1092 	unsigned int w = sbp2_param_workarounds;
1093 
1094 	if (w)
1095 		fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1096 			  "if you need the workarounds parameter for %s\n",
1097 			  tgt->bus_id);
1098 
1099 	if (w & SBP2_WORKAROUND_OVERRIDE)
1100 		goto out;
1101 
1102 	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1103 
1104 		if (sbp2_workarounds_table[i].firmware_revision !=
1105 		    (firmware_revision & 0xffffff00))
1106 			continue;
1107 
1108 		if (sbp2_workarounds_table[i].model != model &&
1109 		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1110 			continue;
1111 
1112 		w |= sbp2_workarounds_table[i].workarounds;
1113 		break;
1114 	}
1115  out:
1116 	if (w)
1117 		fw_notify("Workarounds for %s: 0x%x "
1118 			  "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1119 			  tgt->bus_id, w, firmware_revision, model);
1120 	tgt->workarounds = w;
1121 }
1122 
1123 static struct scsi_host_template scsi_driver_template;
1124 
1125 static int sbp2_probe(struct device *dev)
1126 {
1127 	struct fw_unit *unit = fw_unit(dev);
1128 	struct fw_device *device = fw_parent_device(unit);
1129 	struct sbp2_target *tgt;
1130 	struct sbp2_logical_unit *lu;
1131 	struct Scsi_Host *shost;
1132 	u32 model, firmware_revision;
1133 
1134 	if (dma_get_max_seg_size(device->card->device) > SBP2_MAX_SEG_SIZE)
1135 		BUG_ON(dma_set_max_seg_size(device->card->device,
1136 					    SBP2_MAX_SEG_SIZE));
1137 
1138 	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1139 	if (shost == NULL)
1140 		return -ENOMEM;
1141 
1142 	tgt = (struct sbp2_target *)shost->hostdata;
1143 	dev_set_drvdata(&unit->device, tgt);
1144 	tgt->unit = unit;
1145 	kref_init(&tgt->kref);
1146 	INIT_LIST_HEAD(&tgt->lu_list);
1147 	tgt->bus_id = dev_name(&unit->device);
1148 	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1149 
1150 	if (fw_device_enable_phys_dma(device) < 0)
1151 		goto fail_shost_put;
1152 
1153 	shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1154 
1155 	if (scsi_add_host(shost, &unit->device) < 0)
1156 		goto fail_shost_put;
1157 
1158 	fw_device_get(device);
1159 	fw_unit_get(unit);
1160 
1161 	/* implicit directory ID */
1162 	tgt->directory_id = ((unit->directory - device->config_rom) * 4
1163 			     + CSR_CONFIG_ROM) & 0xffffff;
1164 
1165 	firmware_revision = SBP2_ROM_VALUE_MISSING;
1166 	model		  = SBP2_ROM_VALUE_MISSING;
1167 
1168 	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1169 			       &firmware_revision) < 0)
1170 		goto fail_tgt_put;
1171 
1172 	sbp2_clamp_management_orb_timeout(tgt);
1173 	sbp2_init_workarounds(tgt, model, firmware_revision);
1174 
1175 	/*
1176 	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1177 	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
1178 	 * specifies the max payload size as 2 ^ (max_payload + 2), so
1179 	 * if we set this to max_speed + 7, we get the right value.
1180 	 */
1181 	tgt->max_payload = min(device->max_speed + 7, 10U);
1182 	tgt->max_payload = min(tgt->max_payload, device->card->max_receive - 1);
1183 
1184 	/* Do the login in a workqueue so we can easily reschedule retries. */
1185 	list_for_each_entry(lu, &tgt->lu_list, link)
1186 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1187 	return 0;
1188 
1189  fail_tgt_put:
1190 	sbp2_target_put(tgt);
1191 	return -ENOMEM;
1192 
1193  fail_shost_put:
1194 	scsi_host_put(shost);
1195 	return -ENOMEM;
1196 }
1197 
1198 static int sbp2_remove(struct device *dev)
1199 {
1200 	struct fw_unit *unit = fw_unit(dev);
1201 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1202 
1203 	sbp2_target_put(tgt);
1204 	return 0;
1205 }
1206 
1207 static void sbp2_reconnect(struct work_struct *work)
1208 {
1209 	struct sbp2_logical_unit *lu =
1210 		container_of(work, struct sbp2_logical_unit, work.work);
1211 	struct sbp2_target *tgt = lu->tgt;
1212 	struct fw_device *device = target_device(tgt);
1213 	int generation, node_id, local_node_id;
1214 
1215 	if (fw_device_is_shutdown(device))
1216 		goto out;
1217 
1218 	generation    = device->generation;
1219 	smp_rmb();    /* node IDs must not be older than generation */
1220 	node_id       = device->node_id;
1221 	local_node_id = device->card->node_id;
1222 
1223 	if (sbp2_send_management_orb(lu, node_id, generation,
1224 				     SBP2_RECONNECT_REQUEST,
1225 				     lu->login_id, NULL) < 0) {
1226 		/*
1227 		 * If reconnect was impossible even though we are in the
1228 		 * current generation, fall back and try to log in again.
1229 		 *
1230 		 * We could check for "Function rejected" status, but
1231 		 * looking at the bus generation as simpler and more general.
1232 		 */
1233 		smp_rmb(); /* get current card generation */
1234 		if (generation == device->card->generation ||
1235 		    lu->retries++ >= 5) {
1236 			fw_error("%s: failed to reconnect\n", tgt->bus_id);
1237 			lu->retries = 0;
1238 			PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1239 		}
1240 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1241 		goto out;
1242 	}
1243 
1244 	tgt->node_id      = node_id;
1245 	tgt->address_high = local_node_id << 16;
1246 	smp_wmb();	  /* node IDs must not be older than generation */
1247 	lu->generation	  = generation;
1248 
1249 	fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1250 		  tgt->bus_id, lu->lun, lu->retries);
1251 
1252 	sbp2_agent_reset(lu);
1253 	sbp2_cancel_orbs(lu);
1254 	sbp2_conditionally_unblock(lu);
1255  out:
1256 	sbp2_target_put(tgt);
1257 }
1258 
1259 static void sbp2_update(struct fw_unit *unit)
1260 {
1261 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1262 	struct sbp2_logical_unit *lu;
1263 
1264 	fw_device_enable_phys_dma(fw_parent_device(unit));
1265 
1266 	/*
1267 	 * Fw-core serializes sbp2_update() against sbp2_remove().
1268 	 * Iteration over tgt->lu_list is therefore safe here.
1269 	 */
1270 	list_for_each_entry(lu, &tgt->lu_list, link) {
1271 		sbp2_conditionally_block(lu);
1272 		lu->retries = 0;
1273 		sbp2_queue_work(lu, 0);
1274 	}
1275 }
1276 
1277 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
1278 #define SBP2_SW_VERSION_ENTRY	0x00010483
1279 
1280 static const struct ieee1394_device_id sbp2_id_table[] = {
1281 	{
1282 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1283 				IEEE1394_MATCH_VERSION,
1284 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1285 		.version      = SBP2_SW_VERSION_ENTRY,
1286 	},
1287 	{ }
1288 };
1289 
1290 static struct fw_driver sbp2_driver = {
1291 	.driver   = {
1292 		.owner  = THIS_MODULE,
1293 		.name   = sbp2_driver_name,
1294 		.bus    = &fw_bus_type,
1295 		.probe  = sbp2_probe,
1296 		.remove = sbp2_remove,
1297 	},
1298 	.update   = sbp2_update,
1299 	.id_table = sbp2_id_table,
1300 };
1301 
1302 static void sbp2_unmap_scatterlist(struct device *card_device,
1303 				   struct sbp2_command_orb *orb)
1304 {
1305 	if (scsi_sg_count(orb->cmd))
1306 		dma_unmap_sg(card_device, scsi_sglist(orb->cmd),
1307 			     scsi_sg_count(orb->cmd),
1308 			     orb->cmd->sc_data_direction);
1309 
1310 	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1311 		dma_unmap_single(card_device, orb->page_table_bus,
1312 				 sizeof(orb->page_table), DMA_TO_DEVICE);
1313 }
1314 
1315 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1316 {
1317 	int sam_status;
1318 
1319 	sense_data[0] = 0x70;
1320 	sense_data[1] = 0x0;
1321 	sense_data[2] = sbp2_status[1];
1322 	sense_data[3] = sbp2_status[4];
1323 	sense_data[4] = sbp2_status[5];
1324 	sense_data[5] = sbp2_status[6];
1325 	sense_data[6] = sbp2_status[7];
1326 	sense_data[7] = 10;
1327 	sense_data[8] = sbp2_status[8];
1328 	sense_data[9] = sbp2_status[9];
1329 	sense_data[10] = sbp2_status[10];
1330 	sense_data[11] = sbp2_status[11];
1331 	sense_data[12] = sbp2_status[2];
1332 	sense_data[13] = sbp2_status[3];
1333 	sense_data[14] = sbp2_status[12];
1334 	sense_data[15] = sbp2_status[13];
1335 
1336 	sam_status = sbp2_status[0] & 0x3f;
1337 
1338 	switch (sam_status) {
1339 	case SAM_STAT_GOOD:
1340 	case SAM_STAT_CHECK_CONDITION:
1341 	case SAM_STAT_CONDITION_MET:
1342 	case SAM_STAT_BUSY:
1343 	case SAM_STAT_RESERVATION_CONFLICT:
1344 	case SAM_STAT_COMMAND_TERMINATED:
1345 		return DID_OK << 16 | sam_status;
1346 
1347 	default:
1348 		return DID_ERROR << 16;
1349 	}
1350 }
1351 
1352 static void complete_command_orb(struct sbp2_orb *base_orb,
1353 				 struct sbp2_status *status)
1354 {
1355 	struct sbp2_command_orb *orb =
1356 		container_of(base_orb, struct sbp2_command_orb, base);
1357 	struct fw_device *device = target_device(orb->lu->tgt);
1358 	int result;
1359 
1360 	if (status != NULL) {
1361 		if (STATUS_GET_DEAD(*status))
1362 			sbp2_agent_reset_no_wait(orb->lu);
1363 
1364 		switch (STATUS_GET_RESPONSE(*status)) {
1365 		case SBP2_STATUS_REQUEST_COMPLETE:
1366 			result = DID_OK << 16;
1367 			break;
1368 		case SBP2_STATUS_TRANSPORT_FAILURE:
1369 			result = DID_BUS_BUSY << 16;
1370 			break;
1371 		case SBP2_STATUS_ILLEGAL_REQUEST:
1372 		case SBP2_STATUS_VENDOR_DEPENDENT:
1373 		default:
1374 			result = DID_ERROR << 16;
1375 			break;
1376 		}
1377 
1378 		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1379 			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1380 							   orb->cmd->sense_buffer);
1381 	} else {
1382 		/*
1383 		 * If the orb completes with status == NULL, something
1384 		 * went wrong, typically a bus reset happened mid-orb
1385 		 * or when sending the write (less likely).
1386 		 */
1387 		result = DID_BUS_BUSY << 16;
1388 		sbp2_conditionally_block(orb->lu);
1389 	}
1390 
1391 	dma_unmap_single(device->card->device, orb->base.request_bus,
1392 			 sizeof(orb->request), DMA_TO_DEVICE);
1393 	sbp2_unmap_scatterlist(device->card->device, orb);
1394 
1395 	orb->cmd->result = result;
1396 	orb->done(orb->cmd);
1397 }
1398 
1399 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1400 		struct fw_device *device, struct sbp2_logical_unit *lu)
1401 {
1402 	struct scatterlist *sg = scsi_sglist(orb->cmd);
1403 	int i, n;
1404 
1405 	n = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1406 		       orb->cmd->sc_data_direction);
1407 	if (n == 0)
1408 		goto fail;
1409 
1410 	/*
1411 	 * Handle the special case where there is only one element in
1412 	 * the scatter list by converting it to an immediate block
1413 	 * request. This is also a workaround for broken devices such
1414 	 * as the second generation iPod which doesn't support page
1415 	 * tables.
1416 	 */
1417 	if (n == 1) {
1418 		orb->request.data_descriptor.high =
1419 			cpu_to_be32(lu->tgt->address_high);
1420 		orb->request.data_descriptor.low  =
1421 			cpu_to_be32(sg_dma_address(sg));
1422 		orb->request.misc |=
1423 			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1424 		return 0;
1425 	}
1426 
1427 	for_each_sg(sg, sg, n, i) {
1428 		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1429 		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1430 	}
1431 
1432 	orb->page_table_bus =
1433 		dma_map_single(device->card->device, orb->page_table,
1434 			       sizeof(orb->page_table), DMA_TO_DEVICE);
1435 	if (dma_mapping_error(device->card->device, orb->page_table_bus))
1436 		goto fail_page_table;
1437 
1438 	/*
1439 	 * The data_descriptor pointer is the one case where we need
1440 	 * to fill in the node ID part of the address.  All other
1441 	 * pointers assume that the data referenced reside on the
1442 	 * initiator (i.e. us), but data_descriptor can refer to data
1443 	 * on other nodes so we need to put our ID in descriptor.high.
1444 	 */
1445 	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1446 	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1447 	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1448 					 COMMAND_ORB_DATA_SIZE(n));
1449 
1450 	return 0;
1451 
1452  fail_page_table:
1453 	dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1454 		     scsi_sg_count(orb->cmd), orb->cmd->sc_data_direction);
1455  fail:
1456 	return -ENOMEM;
1457 }
1458 
1459 /* SCSI stack integration */
1460 
1461 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1462 {
1463 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1464 	struct fw_device *device = target_device(lu->tgt);
1465 	struct sbp2_command_orb *orb;
1466 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1467 
1468 	/*
1469 	 * Bidirectional commands are not yet implemented, and unknown
1470 	 * transfer direction not handled.
1471 	 */
1472 	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1473 		fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1474 		cmd->result = DID_ERROR << 16;
1475 		done(cmd);
1476 		return 0;
1477 	}
1478 
1479 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1480 	if (orb == NULL) {
1481 		fw_notify("failed to alloc orb\n");
1482 		return SCSI_MLQUEUE_HOST_BUSY;
1483 	}
1484 
1485 	/* Initialize rcode to something not RCODE_COMPLETE. */
1486 	orb->base.rcode = -1;
1487 	kref_init(&orb->base.kref);
1488 
1489 	orb->lu   = lu;
1490 	orb->done = done;
1491 	orb->cmd  = cmd;
1492 
1493 	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1494 	orb->request.misc = cpu_to_be32(
1495 		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1496 		COMMAND_ORB_SPEED(device->max_speed) |
1497 		COMMAND_ORB_NOTIFY);
1498 
1499 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1500 		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1501 
1502 	generation = device->generation;
1503 	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1504 
1505 	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1506 		goto out;
1507 
1508 	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1509 
1510 	orb->base.callback = complete_command_orb;
1511 	orb->base.request_bus =
1512 		dma_map_single(device->card->device, &orb->request,
1513 			       sizeof(orb->request), DMA_TO_DEVICE);
1514 	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1515 		sbp2_unmap_scatterlist(device->card->device, orb);
1516 		goto out;
1517 	}
1518 
1519 	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1520 		      lu->command_block_agent_address + SBP2_ORB_POINTER);
1521 	retval = 0;
1522  out:
1523 	kref_put(&orb->base.kref, free_orb);
1524 	return retval;
1525 }
1526 
1527 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1528 {
1529 	struct sbp2_logical_unit *lu = sdev->hostdata;
1530 
1531 	/* (Re-)Adding logical units via the SCSI stack is not supported. */
1532 	if (!lu)
1533 		return -ENOSYS;
1534 
1535 	sdev->allow_restart = 1;
1536 
1537 	/* SBP-2 requires quadlet alignment of the data buffers. */
1538 	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1539 
1540 	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1541 		sdev->inquiry_len = 36;
1542 
1543 	return 0;
1544 }
1545 
1546 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1547 {
1548 	struct sbp2_logical_unit *lu = sdev->hostdata;
1549 
1550 	sdev->use_10_for_rw = 1;
1551 
1552 	if (sbp2_param_exclusive_login)
1553 		sdev->manage_start_stop = 1;
1554 
1555 	if (sdev->type == TYPE_ROM)
1556 		sdev->use_10_for_ms = 1;
1557 
1558 	if (sdev->type == TYPE_DISK &&
1559 	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1560 		sdev->skip_ms_page_8 = 1;
1561 
1562 	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1563 		sdev->fix_capacity = 1;
1564 
1565 	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1566 		sdev->start_stop_pwr_cond = 1;
1567 
1568 	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1569 		blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
1570 
1571 	blk_queue_max_segment_size(sdev->request_queue, SBP2_MAX_SEG_SIZE);
1572 
1573 	return 0;
1574 }
1575 
1576 /*
1577  * Called by scsi stack when something has really gone wrong.  Usually
1578  * called when a command has timed-out for some reason.
1579  */
1580 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1581 {
1582 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1583 
1584 	fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1585 	sbp2_agent_reset(lu);
1586 	sbp2_cancel_orbs(lu);
1587 
1588 	return SUCCESS;
1589 }
1590 
1591 /*
1592  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1593  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1594  *
1595  * This is the concatenation of target port identifier and logical unit
1596  * identifier as per SAM-2...SAM-4 annex A.
1597  */
1598 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1599 			struct device_attribute *attr, char *buf)
1600 {
1601 	struct scsi_device *sdev = to_scsi_device(dev);
1602 	struct sbp2_logical_unit *lu;
1603 
1604 	if (!sdev)
1605 		return 0;
1606 
1607 	lu = sdev->hostdata;
1608 
1609 	return sprintf(buf, "%016llx:%06x:%04x\n",
1610 			(unsigned long long)lu->tgt->guid,
1611 			lu->tgt->directory_id, lu->lun);
1612 }
1613 
1614 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1615 
1616 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1617 	&dev_attr_ieee1394_id,
1618 	NULL
1619 };
1620 
1621 static struct scsi_host_template scsi_driver_template = {
1622 	.module			= THIS_MODULE,
1623 	.name			= "SBP-2 IEEE-1394",
1624 	.proc_name		= sbp2_driver_name,
1625 	.queuecommand		= sbp2_scsi_queuecommand,
1626 	.slave_alloc		= sbp2_scsi_slave_alloc,
1627 	.slave_configure	= sbp2_scsi_slave_configure,
1628 	.eh_abort_handler	= sbp2_scsi_abort,
1629 	.this_id		= -1,
1630 	.sg_tablesize		= SG_ALL,
1631 	.use_clustering		= ENABLE_CLUSTERING,
1632 	.cmd_per_lun		= 1,
1633 	.can_queue		= 1,
1634 	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
1635 };
1636 
1637 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1638 MODULE_DESCRIPTION("SCSI over IEEE1394");
1639 MODULE_LICENSE("GPL");
1640 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1641 
1642 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1643 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1644 MODULE_ALIAS("sbp2");
1645 #endif
1646 
1647 static int __init sbp2_init(void)
1648 {
1649 	sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1650 	if (!sbp2_wq)
1651 		return -ENOMEM;
1652 
1653 	return driver_register(&sbp2_driver.driver);
1654 }
1655 
1656 static void __exit sbp2_cleanup(void)
1657 {
1658 	driver_unregister(&sbp2_driver.driver);
1659 	destroy_workqueue(sbp2_wq);
1660 }
1661 
1662 module_init(sbp2_init);
1663 module_exit(sbp2_cleanup);
1664