xref: /openbmc/linux/drivers/firewire/sbp2.c (revision 3213486f)
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 
56 #include <scsi/scsi.h>
57 #include <scsi/scsi_cmnd.h>
58 #include <scsi/scsi_device.h>
59 #include <scsi/scsi_host.h>
60 
61 /*
62  * So far only bridges from Oxford Semiconductor are known to support
63  * concurrent logins. Depending on firmware, four or two concurrent logins
64  * are possible on OXFW911 and newer Oxsemi bridges.
65  *
66  * Concurrent logins are useful together with cluster filesystems.
67  */
68 static bool sbp2_param_exclusive_login = 1;
69 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
70 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
71 		 "(default = Y, use N for concurrent initiators)");
72 
73 /*
74  * Flags for firmware oddities
75  *
76  * - 128kB max transfer
77  *   Limit transfer size. Necessary for some old bridges.
78  *
79  * - 36 byte inquiry
80  *   When scsi_mod probes the device, let the inquiry command look like that
81  *   from MS Windows.
82  *
83  * - skip mode page 8
84  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
85  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
86  *
87  * - fix capacity
88  *   Tell sd_mod to correct the last sector number reported by read_capacity.
89  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
90  *   Don't use this with devices which don't have this bug.
91  *
92  * - delay inquiry
93  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
94  *
95  * - power condition
96  *   Set the power condition field in the START STOP UNIT commands sent by
97  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
98  *   Some disks need this to spin down or to resume properly.
99  *
100  * - override internal blacklist
101  *   Instead of adding to the built-in blacklist, use only the workarounds
102  *   specified in the module load parameter.
103  *   Useful if a blacklist entry interfered with a non-broken device.
104  */
105 #define SBP2_WORKAROUND_128K_MAX_TRANS	0x1
106 #define SBP2_WORKAROUND_INQUIRY_36	0x2
107 #define SBP2_WORKAROUND_MODE_SENSE_8	0x4
108 #define SBP2_WORKAROUND_FIX_CAPACITY	0x8
109 #define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
110 #define SBP2_INQUIRY_DELAY		12
111 #define SBP2_WORKAROUND_POWER_CONDITION	0x20
112 #define SBP2_WORKAROUND_OVERRIDE	0x100
113 
114 static int sbp2_param_workarounds;
115 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
116 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
117 	", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
118 	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
119 	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
120 	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
121 	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
122 	", set power condition in start stop unit = "
123 				  __stringify(SBP2_WORKAROUND_POWER_CONDITION)
124 	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
125 	", or a combination)");
126 
127 /*
128  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
129  * and one struct scsi_device per sbp2_logical_unit.
130  */
131 struct sbp2_logical_unit {
132 	struct sbp2_target *tgt;
133 	struct list_head link;
134 	struct fw_address_handler address_handler;
135 	struct list_head orb_list;
136 
137 	u64 command_block_agent_address;
138 	u16 lun;
139 	int login_id;
140 
141 	/*
142 	 * The generation is updated once we've logged in or reconnected
143 	 * to the logical unit.  Thus, I/O to the device will automatically
144 	 * fail and get retried if it happens in a window where the device
145 	 * is not ready, e.g. after a bus reset but before we reconnect.
146 	 */
147 	int generation;
148 	int retries;
149 	work_func_t workfn;
150 	struct delayed_work work;
151 	bool has_sdev;
152 	bool blocked;
153 };
154 
155 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
156 {
157 	queue_delayed_work(fw_workqueue, &lu->work, delay);
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 fw_unit *unit;
166 	struct list_head lu_list;
167 
168 	u64 management_agent_address;
169 	u64 guid;
170 	int directory_id;
171 	int node_id;
172 	int address_high;
173 	unsigned int workarounds;
174 	unsigned int mgt_orb_timeout;
175 	unsigned int max_payload;
176 
177 	spinlock_t lock;
178 	int dont_block;	/* counter for each logical unit */
179 	int blocked;	/* ditto */
180 };
181 
182 static struct fw_device *target_parent_device(struct sbp2_target *tgt)
183 {
184 	return fw_parent_device(tgt->unit);
185 }
186 
187 static const struct device *tgt_dev(const struct sbp2_target *tgt)
188 {
189 	return &tgt->unit->device;
190 }
191 
192 static const struct device *lu_dev(const struct sbp2_logical_unit *lu)
193 {
194 	return &lu->tgt->unit->device;
195 }
196 
197 /* Impossible login_id, to detect logout attempt before successful login */
198 #define INVALID_LOGIN_ID 0x10000
199 
200 #define SBP2_ORB_TIMEOUT		2000U		/* Timeout in ms */
201 #define SBP2_ORB_NULL			0x80000000
202 #define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
203 #define SBP2_CYCLE_LIMIT		(0xc8 << 12)	/* 200 125us cycles */
204 
205 /*
206  * There is no transport protocol limit to the CDB length,  but we implement
207  * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
208  */
209 #define SBP2_MAX_CDB_SIZE		16
210 
211 /*
212  * The maximum SBP-2 data buffer size is 0xffff.  We quadlet-align this
213  * for compatibility with earlier versions of this driver.
214  */
215 #define SBP2_MAX_SEG_SIZE		0xfffc
216 
217 /* Unit directory keys */
218 #define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
219 #define SBP2_CSR_FIRMWARE_REVISION	0x3c
220 #define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
221 #define SBP2_CSR_UNIT_UNIQUE_ID		0x8d
222 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4
223 
224 /* Management orb opcodes */
225 #define SBP2_LOGIN_REQUEST		0x0
226 #define SBP2_QUERY_LOGINS_REQUEST	0x1
227 #define SBP2_RECONNECT_REQUEST		0x3
228 #define SBP2_SET_PASSWORD_REQUEST	0x4
229 #define SBP2_LOGOUT_REQUEST		0x7
230 #define SBP2_ABORT_TASK_REQUEST		0xb
231 #define SBP2_ABORT_TASK_SET		0xc
232 #define SBP2_LOGICAL_UNIT_RESET		0xe
233 #define SBP2_TARGET_RESET_REQUEST	0xf
234 
235 /* Offsets for command block agent registers */
236 #define SBP2_AGENT_STATE		0x00
237 #define SBP2_AGENT_RESET		0x04
238 #define SBP2_ORB_POINTER		0x08
239 #define SBP2_DOORBELL			0x10
240 #define SBP2_UNSOLICITED_STATUS_ENABLE	0x14
241 
242 /* Status write response codes */
243 #define SBP2_STATUS_REQUEST_COMPLETE	0x0
244 #define SBP2_STATUS_TRANSPORT_FAILURE	0x1
245 #define SBP2_STATUS_ILLEGAL_REQUEST	0x2
246 #define SBP2_STATUS_VENDOR_DEPENDENT	0x3
247 
248 #define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
249 #define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
250 #define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
251 #define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
252 #define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
253 #define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
254 #define STATUS_GET_ORB_LOW(v)		((v).orb_low)
255 #define STATUS_GET_DATA(v)		((v).data)
256 
257 struct sbp2_status {
258 	u32 status;
259 	u32 orb_low;
260 	u8 data[24];
261 };
262 
263 struct sbp2_pointer {
264 	__be32 high;
265 	__be32 low;
266 };
267 
268 struct sbp2_orb {
269 	struct fw_transaction t;
270 	struct kref kref;
271 	dma_addr_t request_bus;
272 	int rcode;
273 	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
274 	struct sbp2_logical_unit *lu;
275 	struct list_head link;
276 };
277 
278 #define MANAGEMENT_ORB_LUN(v)			((v))
279 #define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
280 #define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
281 #define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
282 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
283 #define MANAGEMENT_ORB_NOTIFY			((1) << 31)
284 
285 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
286 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
287 
288 struct sbp2_management_orb {
289 	struct sbp2_orb base;
290 	struct {
291 		struct sbp2_pointer password;
292 		struct sbp2_pointer response;
293 		__be32 misc;
294 		__be32 length;
295 		struct sbp2_pointer status_fifo;
296 	} request;
297 	__be32 response[4];
298 	dma_addr_t response_bus;
299 	struct completion done;
300 	struct sbp2_status status;
301 };
302 
303 struct sbp2_login_response {
304 	__be32 misc;
305 	struct sbp2_pointer command_block_agent;
306 	__be32 reconnect_hold;
307 };
308 #define COMMAND_ORB_DATA_SIZE(v)	((v))
309 #define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
310 #define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
311 #define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
312 #define COMMAND_ORB_SPEED(v)		((v) << 24)
313 #define COMMAND_ORB_DIRECTION		((1) << 27)
314 #define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
315 #define COMMAND_ORB_NOTIFY		((1) << 31)
316 
317 struct sbp2_command_orb {
318 	struct sbp2_orb base;
319 	struct {
320 		struct sbp2_pointer next;
321 		struct sbp2_pointer data_descriptor;
322 		__be32 misc;
323 		u8 command_block[SBP2_MAX_CDB_SIZE];
324 	} request;
325 	struct scsi_cmnd *cmd;
326 
327 	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
328 	dma_addr_t page_table_bus;
329 };
330 
331 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
332 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
333 
334 /*
335  * List of devices with known bugs.
336  *
337  * The firmware_revision field, masked with 0xffff00, is the best
338  * indicator for the type of bridge chip of a device.  It yields a few
339  * false positives but this did not break correctly behaving devices
340  * so far.
341  */
342 static const struct {
343 	u32 firmware_revision;
344 	u32 model;
345 	unsigned int workarounds;
346 } sbp2_workarounds_table[] = {
347 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
348 		.firmware_revision	= 0x002800,
349 		.model			= 0x001010,
350 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
351 					  SBP2_WORKAROUND_MODE_SENSE_8 |
352 					  SBP2_WORKAROUND_POWER_CONDITION,
353 	},
354 	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
355 		.firmware_revision	= 0x002800,
356 		.model			= 0x000000,
357 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
358 	},
359 	/* Initio bridges, actually only needed for some older ones */ {
360 		.firmware_revision	= 0x000200,
361 		.model			= SBP2_ROM_VALUE_WILDCARD,
362 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
363 	},
364 	/* PL-3507 bridge with Prolific firmware */ {
365 		.firmware_revision	= 0x012800,
366 		.model			= SBP2_ROM_VALUE_WILDCARD,
367 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
368 	},
369 	/* Symbios bridge */ {
370 		.firmware_revision	= 0xa0b800,
371 		.model			= SBP2_ROM_VALUE_WILDCARD,
372 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
373 	},
374 	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
375 		.firmware_revision	= 0x002600,
376 		.model			= SBP2_ROM_VALUE_WILDCARD,
377 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
378 	},
379 	/*
380 	 * iPod 2nd generation: needs 128k max transfer size workaround
381 	 * iPod 3rd generation: needs fix capacity workaround
382 	 */
383 	{
384 		.firmware_revision	= 0x0a2700,
385 		.model			= 0x000000,
386 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
387 					  SBP2_WORKAROUND_FIX_CAPACITY,
388 	},
389 	/* iPod 4th generation */ {
390 		.firmware_revision	= 0x0a2700,
391 		.model			= 0x000021,
392 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
393 	},
394 	/* iPod mini */ {
395 		.firmware_revision	= 0x0a2700,
396 		.model			= 0x000022,
397 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
398 	},
399 	/* iPod mini */ {
400 		.firmware_revision	= 0x0a2700,
401 		.model			= 0x000023,
402 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
403 	},
404 	/* iPod Photo */ {
405 		.firmware_revision	= 0x0a2700,
406 		.model			= 0x00007e,
407 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
408 	}
409 };
410 
411 static void free_orb(struct kref *kref)
412 {
413 	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
414 
415 	kfree(orb);
416 }
417 
418 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
419 			      int tcode, int destination, int source,
420 			      int generation, unsigned long long offset,
421 			      void *payload, size_t length, void *callback_data)
422 {
423 	struct sbp2_logical_unit *lu = callback_data;
424 	struct sbp2_orb *orb;
425 	struct sbp2_status status;
426 	unsigned long flags;
427 
428 	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
429 	    length < 8 || length > sizeof(status)) {
430 		fw_send_response(card, request, RCODE_TYPE_ERROR);
431 		return;
432 	}
433 
434 	status.status  = be32_to_cpup(payload);
435 	status.orb_low = be32_to_cpup(payload + 4);
436 	memset(status.data, 0, sizeof(status.data));
437 	if (length > 8)
438 		memcpy(status.data, payload + 8, length - 8);
439 
440 	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
441 		dev_notice(lu_dev(lu),
442 			   "non-ORB related status write, not handled\n");
443 		fw_send_response(card, request, RCODE_COMPLETE);
444 		return;
445 	}
446 
447 	/* Lookup the orb corresponding to this status write. */
448 	spin_lock_irqsave(&lu->tgt->lock, flags);
449 	list_for_each_entry(orb, &lu->orb_list, link) {
450 		if (STATUS_GET_ORB_HIGH(status) == 0 &&
451 		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
452 			orb->rcode = RCODE_COMPLETE;
453 			list_del(&orb->link);
454 			break;
455 		}
456 	}
457 	spin_unlock_irqrestore(&lu->tgt->lock, flags);
458 
459 	if (&orb->link != &lu->orb_list) {
460 		orb->callback(orb, &status);
461 		kref_put(&orb->kref, free_orb); /* orb callback reference */
462 	} else {
463 		dev_err(lu_dev(lu), "status write for unknown ORB\n");
464 	}
465 
466 	fw_send_response(card, request, RCODE_COMPLETE);
467 }
468 
469 static void complete_transaction(struct fw_card *card, int rcode,
470 				 void *payload, size_t length, void *data)
471 {
472 	struct sbp2_orb *orb = data;
473 	unsigned long flags;
474 
475 	/*
476 	 * This is a little tricky.  We can get the status write for
477 	 * the orb before we get this callback.  The status write
478 	 * handler above will assume the orb pointer transaction was
479 	 * successful and set the rcode to RCODE_COMPLETE for the orb.
480 	 * So this callback only sets the rcode if it hasn't already
481 	 * been set and only does the cleanup if the transaction
482 	 * failed and we didn't already get a status write.
483 	 */
484 	spin_lock_irqsave(&orb->lu->tgt->lock, flags);
485 
486 	if (orb->rcode == -1)
487 		orb->rcode = rcode;
488 	if (orb->rcode != RCODE_COMPLETE) {
489 		list_del(&orb->link);
490 		spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
491 
492 		orb->callback(orb, NULL);
493 		kref_put(&orb->kref, free_orb); /* orb callback reference */
494 	} else {
495 		spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
496 	}
497 
498 	kref_put(&orb->kref, free_orb); /* transaction callback reference */
499 }
500 
501 static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
502 			  int node_id, int generation, u64 offset)
503 {
504 	struct fw_device *device = target_parent_device(lu->tgt);
505 	struct sbp2_pointer orb_pointer;
506 	unsigned long flags;
507 
508 	orb_pointer.high = 0;
509 	orb_pointer.low = cpu_to_be32(orb->request_bus);
510 
511 	orb->lu = lu;
512 	spin_lock_irqsave(&lu->tgt->lock, flags);
513 	list_add_tail(&orb->link, &lu->orb_list);
514 	spin_unlock_irqrestore(&lu->tgt->lock, flags);
515 
516 	kref_get(&orb->kref); /* transaction callback reference */
517 	kref_get(&orb->kref); /* orb callback reference */
518 
519 	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
520 			node_id, generation, device->max_speed, offset,
521 			&orb_pointer, 8, complete_transaction, orb);
522 }
523 
524 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
525 {
526 	struct fw_device *device = target_parent_device(lu->tgt);
527 	struct sbp2_orb *orb, *next;
528 	struct list_head list;
529 	int retval = -ENOENT;
530 
531 	INIT_LIST_HEAD(&list);
532 	spin_lock_irq(&lu->tgt->lock);
533 	list_splice_init(&lu->orb_list, &list);
534 	spin_unlock_irq(&lu->tgt->lock);
535 
536 	list_for_each_entry_safe(orb, next, &list, link) {
537 		retval = 0;
538 		if (fw_cancel_transaction(device->card, &orb->t) == 0)
539 			continue;
540 
541 		orb->rcode = RCODE_CANCELLED;
542 		orb->callback(orb, NULL);
543 		kref_put(&orb->kref, free_orb); /* orb callback reference */
544 	}
545 
546 	return retval;
547 }
548 
549 static void complete_management_orb(struct sbp2_orb *base_orb,
550 				    struct sbp2_status *status)
551 {
552 	struct sbp2_management_orb *orb =
553 		container_of(base_orb, struct sbp2_management_orb, base);
554 
555 	if (status)
556 		memcpy(&orb->status, status, sizeof(*status));
557 	complete(&orb->done);
558 }
559 
560 static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
561 				    int generation, int function,
562 				    int lun_or_login_id, void *response)
563 {
564 	struct fw_device *device = target_parent_device(lu->tgt);
565 	struct sbp2_management_orb *orb;
566 	unsigned int timeout;
567 	int retval = -ENOMEM;
568 
569 	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
570 		return 0;
571 
572 	orb = kzalloc(sizeof(*orb), GFP_NOIO);
573 	if (orb == NULL)
574 		return -ENOMEM;
575 
576 	kref_init(&orb->base.kref);
577 	orb->response_bus =
578 		dma_map_single(device->card->device, &orb->response,
579 			       sizeof(orb->response), DMA_FROM_DEVICE);
580 	if (dma_mapping_error(device->card->device, orb->response_bus))
581 		goto fail_mapping_response;
582 
583 	orb->request.response.high = 0;
584 	orb->request.response.low  = cpu_to_be32(orb->response_bus);
585 
586 	orb->request.misc = cpu_to_be32(
587 		MANAGEMENT_ORB_NOTIFY |
588 		MANAGEMENT_ORB_FUNCTION(function) |
589 		MANAGEMENT_ORB_LUN(lun_or_login_id));
590 	orb->request.length = cpu_to_be32(
591 		MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
592 
593 	orb->request.status_fifo.high =
594 		cpu_to_be32(lu->address_handler.offset >> 32);
595 	orb->request.status_fifo.low  =
596 		cpu_to_be32(lu->address_handler.offset);
597 
598 	if (function == SBP2_LOGIN_REQUEST) {
599 		/* Ask for 2^2 == 4 seconds reconnect grace period */
600 		orb->request.misc |= cpu_to_be32(
601 			MANAGEMENT_ORB_RECONNECT(2) |
602 			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
603 		timeout = lu->tgt->mgt_orb_timeout;
604 	} else {
605 		timeout = SBP2_ORB_TIMEOUT;
606 	}
607 
608 	init_completion(&orb->done);
609 	orb->base.callback = complete_management_orb;
610 
611 	orb->base.request_bus =
612 		dma_map_single(device->card->device, &orb->request,
613 			       sizeof(orb->request), DMA_TO_DEVICE);
614 	if (dma_mapping_error(device->card->device, orb->base.request_bus))
615 		goto fail_mapping_request;
616 
617 	sbp2_send_orb(&orb->base, lu, node_id, generation,
618 		      lu->tgt->management_agent_address);
619 
620 	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
621 
622 	retval = -EIO;
623 	if (sbp2_cancel_orbs(lu) == 0) {
624 		dev_err(lu_dev(lu), "ORB reply timed out, rcode 0x%02x\n",
625 			orb->base.rcode);
626 		goto out;
627 	}
628 
629 	if (orb->base.rcode != RCODE_COMPLETE) {
630 		dev_err(lu_dev(lu), "management write failed, rcode 0x%02x\n",
631 			orb->base.rcode);
632 		goto out;
633 	}
634 
635 	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
636 	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
637 		dev_err(lu_dev(lu), "error status: %d:%d\n",
638 			 STATUS_GET_RESPONSE(orb->status),
639 			 STATUS_GET_SBP_STATUS(orb->status));
640 		goto out;
641 	}
642 
643 	retval = 0;
644  out:
645 	dma_unmap_single(device->card->device, orb->base.request_bus,
646 			 sizeof(orb->request), DMA_TO_DEVICE);
647  fail_mapping_request:
648 	dma_unmap_single(device->card->device, orb->response_bus,
649 			 sizeof(orb->response), DMA_FROM_DEVICE);
650  fail_mapping_response:
651 	if (response)
652 		memcpy(response, orb->response, sizeof(orb->response));
653 	kref_put(&orb->base.kref, free_orb);
654 
655 	return retval;
656 }
657 
658 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
659 {
660 	struct fw_device *device = target_parent_device(lu->tgt);
661 	__be32 d = 0;
662 
663 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
664 			   lu->tgt->node_id, lu->generation, device->max_speed,
665 			   lu->command_block_agent_address + SBP2_AGENT_RESET,
666 			   &d, 4);
667 }
668 
669 static void complete_agent_reset_write_no_wait(struct fw_card *card,
670 		int rcode, void *payload, size_t length, void *data)
671 {
672 	kfree(data);
673 }
674 
675 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
676 {
677 	struct fw_device *device = target_parent_device(lu->tgt);
678 	struct fw_transaction *t;
679 	static __be32 d;
680 
681 	t = kmalloc(sizeof(*t), GFP_ATOMIC);
682 	if (t == NULL)
683 		return;
684 
685 	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
686 			lu->tgt->node_id, lu->generation, device->max_speed,
687 			lu->command_block_agent_address + SBP2_AGENT_RESET,
688 			&d, 4, complete_agent_reset_write_no_wait, t);
689 }
690 
691 static inline void sbp2_allow_block(struct sbp2_target *tgt)
692 {
693 	spin_lock_irq(&tgt->lock);
694 	--tgt->dont_block;
695 	spin_unlock_irq(&tgt->lock);
696 }
697 
698 /*
699  * Blocks lu->tgt if all of the following conditions are met:
700  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
701  *     logical units have been finished (indicated by dont_block == 0).
702  *   - lu->generation is stale.
703  *
704  * Note, scsi_block_requests() must be called while holding tgt->lock,
705  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
706  * unblock the target.
707  */
708 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
709 {
710 	struct sbp2_target *tgt = lu->tgt;
711 	struct fw_card *card = target_parent_device(tgt)->card;
712 	struct Scsi_Host *shost =
713 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
714 	unsigned long flags;
715 
716 	spin_lock_irqsave(&tgt->lock, flags);
717 	if (!tgt->dont_block && !lu->blocked &&
718 	    lu->generation != card->generation) {
719 		lu->blocked = true;
720 		if (++tgt->blocked == 1)
721 			scsi_block_requests(shost);
722 	}
723 	spin_unlock_irqrestore(&tgt->lock, flags);
724 }
725 
726 /*
727  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
728  * Note, it is harmless to run scsi_unblock_requests() outside the
729  * tgt->lock protected section.  On the other hand, running it inside
730  * the section might clash with shost->host_lock.
731  */
732 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
733 {
734 	struct sbp2_target *tgt = lu->tgt;
735 	struct fw_card *card = target_parent_device(tgt)->card;
736 	struct Scsi_Host *shost =
737 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
738 	bool unblock = false;
739 
740 	spin_lock_irq(&tgt->lock);
741 	if (lu->blocked && lu->generation == card->generation) {
742 		lu->blocked = false;
743 		unblock = --tgt->blocked == 0;
744 	}
745 	spin_unlock_irq(&tgt->lock);
746 
747 	if (unblock)
748 		scsi_unblock_requests(shost);
749 }
750 
751 /*
752  * Prevents future blocking of tgt and unblocks it.
753  * Note, it is harmless to run scsi_unblock_requests() outside the
754  * tgt->lock protected section.  On the other hand, running it inside
755  * the section might clash with shost->host_lock.
756  */
757 static void sbp2_unblock(struct sbp2_target *tgt)
758 {
759 	struct Scsi_Host *shost =
760 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
761 
762 	spin_lock_irq(&tgt->lock);
763 	++tgt->dont_block;
764 	spin_unlock_irq(&tgt->lock);
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 /*
781  * Write retransmit retry values into the BUSY_TIMEOUT register.
782  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
783  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
784  *   saner value after logging into the device.
785  * - The dual-phase retry protocol is optional to implement, and if not
786  *   supported, writes to the dual-phase portion of the register will be
787  *   ignored. We try to write the original 1394-1995 default here.
788  * - In the case of devices that are also SBP-3-compliant, all writes are
789  *   ignored, as the register is read-only, but contains single-phase retry of
790  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
791  *   write attempt is safe and yields more consistent behavior for all devices.
792  *
793  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
794  * and section 6.4 of the SBP-3 spec for further details.
795  */
796 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
797 {
798 	struct fw_device *device = target_parent_device(lu->tgt);
799 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
800 
801 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
802 			   lu->tgt->node_id, lu->generation, device->max_speed,
803 			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &d, 4);
804 }
805 
806 static void sbp2_reconnect(struct work_struct *work);
807 
808 static void sbp2_login(struct work_struct *work)
809 {
810 	struct sbp2_logical_unit *lu =
811 		container_of(work, struct sbp2_logical_unit, work.work);
812 	struct sbp2_target *tgt = lu->tgt;
813 	struct fw_device *device = target_parent_device(tgt);
814 	struct Scsi_Host *shost;
815 	struct scsi_device *sdev;
816 	struct sbp2_login_response response;
817 	int generation, node_id, local_node_id;
818 
819 	if (fw_device_is_shutdown(device))
820 		return;
821 
822 	generation    = device->generation;
823 	smp_rmb();    /* node IDs must not be older than generation */
824 	node_id       = device->node_id;
825 	local_node_id = device->card->node_id;
826 
827 	/* If this is a re-login attempt, log out, or we might be rejected. */
828 	if (lu->has_sdev)
829 		sbp2_send_management_orb(lu, device->node_id, generation,
830 				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
831 
832 	if (sbp2_send_management_orb(lu, node_id, generation,
833 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
834 		if (lu->retries++ < 5) {
835 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
836 		} else {
837 			dev_err(tgt_dev(tgt), "failed to login to LUN %04x\n",
838 				lu->lun);
839 			/* Let any waiting I/O fail from now on. */
840 			sbp2_unblock(lu->tgt);
841 		}
842 		return;
843 	}
844 
845 	tgt->node_id	  = node_id;
846 	tgt->address_high = local_node_id << 16;
847 	smp_wmb();	  /* node IDs must not be older than generation */
848 	lu->generation	  = generation;
849 
850 	lu->command_block_agent_address =
851 		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
852 		      << 32) | be32_to_cpu(response.command_block_agent.low);
853 	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
854 
855 	dev_notice(tgt_dev(tgt), "logged in to LUN %04x (%d retries)\n",
856 		   lu->lun, lu->retries);
857 
858 	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
859 	sbp2_set_busy_timeout(lu);
860 
861 	lu->workfn = sbp2_reconnect;
862 	sbp2_agent_reset(lu);
863 
864 	/* This was a re-login. */
865 	if (lu->has_sdev) {
866 		sbp2_cancel_orbs(lu);
867 		sbp2_conditionally_unblock(lu);
868 
869 		return;
870 	}
871 
872 	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
873 		ssleep(SBP2_INQUIRY_DELAY);
874 
875 	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
876 	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
877 	/*
878 	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
879 	 * Therefore __scsi_add_device() will get into trouble if a bus reset
880 	 * happens in parallel.  It will either fail or leave us with an
881 	 * unusable sdev.  As a workaround we check for this and retry the
882 	 * whole login and SCSI probing.
883 	 */
884 
885 	/* Reported error during __scsi_add_device() */
886 	if (IS_ERR(sdev))
887 		goto out_logout_login;
888 
889 	/* Unreported error during __scsi_add_device() */
890 	smp_rmb(); /* get current card generation */
891 	if (generation != device->card->generation) {
892 		scsi_remove_device(sdev);
893 		scsi_device_put(sdev);
894 		goto out_logout_login;
895 	}
896 
897 	/* No error during __scsi_add_device() */
898 	lu->has_sdev = true;
899 	scsi_device_put(sdev);
900 	sbp2_allow_block(tgt);
901 
902 	return;
903 
904  out_logout_login:
905 	smp_rmb(); /* generation may have changed */
906 	generation = device->generation;
907 	smp_rmb(); /* node_id must not be older than generation */
908 
909 	sbp2_send_management_orb(lu, device->node_id, generation,
910 				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
911 	/*
912 	 * If a bus reset happened, sbp2_update will have requeued
913 	 * lu->work already.  Reset the work from reconnect to login.
914 	 */
915 	lu->workfn = sbp2_login;
916 }
917 
918 static void sbp2_reconnect(struct work_struct *work)
919 {
920 	struct sbp2_logical_unit *lu =
921 		container_of(work, struct sbp2_logical_unit, work.work);
922 	struct sbp2_target *tgt = lu->tgt;
923 	struct fw_device *device = target_parent_device(tgt);
924 	int generation, node_id, local_node_id;
925 
926 	if (fw_device_is_shutdown(device))
927 		return;
928 
929 	generation    = device->generation;
930 	smp_rmb();    /* node IDs must not be older than generation */
931 	node_id       = device->node_id;
932 	local_node_id = device->card->node_id;
933 
934 	if (sbp2_send_management_orb(lu, node_id, generation,
935 				     SBP2_RECONNECT_REQUEST,
936 				     lu->login_id, NULL) < 0) {
937 		/*
938 		 * If reconnect was impossible even though we are in the
939 		 * current generation, fall back and try to log in again.
940 		 *
941 		 * We could check for "Function rejected" status, but
942 		 * looking at the bus generation as simpler and more general.
943 		 */
944 		smp_rmb(); /* get current card generation */
945 		if (generation == device->card->generation ||
946 		    lu->retries++ >= 5) {
947 			dev_err(tgt_dev(tgt), "failed to reconnect\n");
948 			lu->retries = 0;
949 			lu->workfn = sbp2_login;
950 		}
951 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
952 
953 		return;
954 	}
955 
956 	tgt->node_id      = node_id;
957 	tgt->address_high = local_node_id << 16;
958 	smp_wmb();	  /* node IDs must not be older than generation */
959 	lu->generation	  = generation;
960 
961 	dev_notice(tgt_dev(tgt), "reconnected to LUN %04x (%d retries)\n",
962 		   lu->lun, lu->retries);
963 
964 	sbp2_agent_reset(lu);
965 	sbp2_cancel_orbs(lu);
966 	sbp2_conditionally_unblock(lu);
967 }
968 
969 static void sbp2_lu_workfn(struct work_struct *work)
970 {
971 	struct sbp2_logical_unit *lu = container_of(to_delayed_work(work),
972 						struct sbp2_logical_unit, work);
973 	lu->workfn(work);
974 }
975 
976 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
977 {
978 	struct sbp2_logical_unit *lu;
979 
980 	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
981 	if (!lu)
982 		return -ENOMEM;
983 
984 	lu->address_handler.length           = 0x100;
985 	lu->address_handler.address_callback = sbp2_status_write;
986 	lu->address_handler.callback_data    = lu;
987 
988 	if (fw_core_add_address_handler(&lu->address_handler,
989 					&fw_high_memory_region) < 0) {
990 		kfree(lu);
991 		return -ENOMEM;
992 	}
993 
994 	lu->tgt      = tgt;
995 	lu->lun      = lun_entry & 0xffff;
996 	lu->login_id = INVALID_LOGIN_ID;
997 	lu->retries  = 0;
998 	lu->has_sdev = false;
999 	lu->blocked  = false;
1000 	++tgt->dont_block;
1001 	INIT_LIST_HEAD(&lu->orb_list);
1002 	lu->workfn = sbp2_login;
1003 	INIT_DELAYED_WORK(&lu->work, sbp2_lu_workfn);
1004 
1005 	list_add_tail(&lu->link, &tgt->lu_list);
1006 	return 0;
1007 }
1008 
1009 static void sbp2_get_unit_unique_id(struct sbp2_target *tgt,
1010 				    const u32 *leaf)
1011 {
1012 	if ((leaf[0] & 0xffff0000) == 0x00020000)
1013 		tgt->guid = (u64)leaf[1] << 32 | leaf[2];
1014 }
1015 
1016 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
1017 				      const u32 *directory)
1018 {
1019 	struct fw_csr_iterator ci;
1020 	int key, value;
1021 
1022 	fw_csr_iterator_init(&ci, directory);
1023 	while (fw_csr_iterator_next(&ci, &key, &value))
1024 		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1025 		    sbp2_add_logical_unit(tgt, value) < 0)
1026 			return -ENOMEM;
1027 	return 0;
1028 }
1029 
1030 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
1031 			      u32 *model, u32 *firmware_revision)
1032 {
1033 	struct fw_csr_iterator ci;
1034 	int key, value;
1035 
1036 	fw_csr_iterator_init(&ci, directory);
1037 	while (fw_csr_iterator_next(&ci, &key, &value)) {
1038 		switch (key) {
1039 
1040 		case CSR_DEPENDENT_INFO | CSR_OFFSET:
1041 			tgt->management_agent_address =
1042 					CSR_REGISTER_BASE + 4 * value;
1043 			break;
1044 
1045 		case CSR_DIRECTORY_ID:
1046 			tgt->directory_id = value;
1047 			break;
1048 
1049 		case CSR_MODEL:
1050 			*model = value;
1051 			break;
1052 
1053 		case SBP2_CSR_FIRMWARE_REVISION:
1054 			*firmware_revision = value;
1055 			break;
1056 
1057 		case SBP2_CSR_UNIT_CHARACTERISTICS:
1058 			/* the timeout value is stored in 500ms units */
1059 			tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
1060 			break;
1061 
1062 		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1063 			if (sbp2_add_logical_unit(tgt, value) < 0)
1064 				return -ENOMEM;
1065 			break;
1066 
1067 		case SBP2_CSR_UNIT_UNIQUE_ID:
1068 			sbp2_get_unit_unique_id(tgt, ci.p - 1 + value);
1069 			break;
1070 
1071 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1072 			/* Adjust for the increment in the iterator */
1073 			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1074 				return -ENOMEM;
1075 			break;
1076 		}
1077 	}
1078 	return 0;
1079 }
1080 
1081 /*
1082  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
1083  * provided in the config rom. Most devices do provide a value, which
1084  * we'll use for login management orbs, but with some sane limits.
1085  */
1086 static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
1087 {
1088 	unsigned int timeout = tgt->mgt_orb_timeout;
1089 
1090 	if (timeout > 40000)
1091 		dev_notice(tgt_dev(tgt), "%ds mgt_ORB_timeout limited to 40s\n",
1092 			   timeout / 1000);
1093 
1094 	tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
1095 }
1096 
1097 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1098 				  u32 firmware_revision)
1099 {
1100 	int i;
1101 	unsigned int w = sbp2_param_workarounds;
1102 
1103 	if (w)
1104 		dev_notice(tgt_dev(tgt),
1105 			   "Please notify linux1394-devel@lists.sf.net "
1106 			   "if you need the workarounds parameter\n");
1107 
1108 	if (w & SBP2_WORKAROUND_OVERRIDE)
1109 		goto out;
1110 
1111 	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1112 
1113 		if (sbp2_workarounds_table[i].firmware_revision !=
1114 		    (firmware_revision & 0xffffff00))
1115 			continue;
1116 
1117 		if (sbp2_workarounds_table[i].model != model &&
1118 		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1119 			continue;
1120 
1121 		w |= sbp2_workarounds_table[i].workarounds;
1122 		break;
1123 	}
1124  out:
1125 	if (w)
1126 		dev_notice(tgt_dev(tgt), "workarounds 0x%x "
1127 			   "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1128 			   w, firmware_revision, model);
1129 	tgt->workarounds = w;
1130 }
1131 
1132 static struct scsi_host_template scsi_driver_template;
1133 static void sbp2_remove(struct fw_unit *unit);
1134 
1135 static int sbp2_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
1136 {
1137 	struct fw_device *device = fw_parent_device(unit);
1138 	struct sbp2_target *tgt;
1139 	struct sbp2_logical_unit *lu;
1140 	struct Scsi_Host *shost;
1141 	u32 model, firmware_revision;
1142 
1143 	/* cannot (or should not) handle targets on the local node */
1144 	if (device->is_local)
1145 		return -ENODEV;
1146 
1147 	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1148 	if (shost == NULL)
1149 		return -ENOMEM;
1150 
1151 	tgt = (struct sbp2_target *)shost->hostdata;
1152 	dev_set_drvdata(&unit->device, tgt);
1153 	tgt->unit = unit;
1154 	INIT_LIST_HEAD(&tgt->lu_list);
1155 	spin_lock_init(&tgt->lock);
1156 	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1157 
1158 	if (fw_device_enable_phys_dma(device) < 0)
1159 		goto fail_shost_put;
1160 
1161 	shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1162 
1163 	if (scsi_add_host_with_dma(shost, &unit->device,
1164 				   device->card->device) < 0)
1165 		goto fail_shost_put;
1166 
1167 	/* implicit directory ID */
1168 	tgt->directory_id = ((unit->directory - device->config_rom) * 4
1169 			     + CSR_CONFIG_ROM) & 0xffffff;
1170 
1171 	firmware_revision = SBP2_ROM_VALUE_MISSING;
1172 	model		  = SBP2_ROM_VALUE_MISSING;
1173 
1174 	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1175 			       &firmware_revision) < 0)
1176 		goto fail_remove;
1177 
1178 	sbp2_clamp_management_orb_timeout(tgt);
1179 	sbp2_init_workarounds(tgt, model, firmware_revision);
1180 
1181 	/*
1182 	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1183 	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
1184 	 * specifies the max payload size as 2 ^ (max_payload + 2), so
1185 	 * if we set this to max_speed + 7, we get the right value.
1186 	 */
1187 	tgt->max_payload = min3(device->max_speed + 7, 10U,
1188 				device->card->max_receive - 1);
1189 
1190 	/* Do the login in a workqueue so we can easily reschedule retries. */
1191 	list_for_each_entry(lu, &tgt->lu_list, link)
1192 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1193 
1194 	return 0;
1195 
1196  fail_remove:
1197 	sbp2_remove(unit);
1198 	return -ENOMEM;
1199 
1200  fail_shost_put:
1201 	scsi_host_put(shost);
1202 	return -ENOMEM;
1203 }
1204 
1205 static void sbp2_update(struct fw_unit *unit)
1206 {
1207 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1208 	struct sbp2_logical_unit *lu;
1209 
1210 	fw_device_enable_phys_dma(fw_parent_device(unit));
1211 
1212 	/*
1213 	 * Fw-core serializes sbp2_update() against sbp2_remove().
1214 	 * Iteration over tgt->lu_list is therefore safe here.
1215 	 */
1216 	list_for_each_entry(lu, &tgt->lu_list, link) {
1217 		sbp2_conditionally_block(lu);
1218 		lu->retries = 0;
1219 		sbp2_queue_work(lu, 0);
1220 	}
1221 }
1222 
1223 static void sbp2_remove(struct fw_unit *unit)
1224 {
1225 	struct fw_device *device = fw_parent_device(unit);
1226 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1227 	struct sbp2_logical_unit *lu, *next;
1228 	struct Scsi_Host *shost =
1229 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
1230 	struct scsi_device *sdev;
1231 
1232 	/* prevent deadlocks */
1233 	sbp2_unblock(tgt);
1234 
1235 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
1236 		cancel_delayed_work_sync(&lu->work);
1237 		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
1238 		if (sdev) {
1239 			scsi_remove_device(sdev);
1240 			scsi_device_put(sdev);
1241 		}
1242 		if (lu->login_id != INVALID_LOGIN_ID) {
1243 			int generation, node_id;
1244 			/*
1245 			 * tgt->node_id may be obsolete here if we failed
1246 			 * during initial login or after a bus reset where
1247 			 * the topology changed.
1248 			 */
1249 			generation = device->generation;
1250 			smp_rmb(); /* node_id vs. generation */
1251 			node_id    = device->node_id;
1252 			sbp2_send_management_orb(lu, node_id, generation,
1253 						 SBP2_LOGOUT_REQUEST,
1254 						 lu->login_id, NULL);
1255 		}
1256 		fw_core_remove_address_handler(&lu->address_handler);
1257 		list_del(&lu->link);
1258 		kfree(lu);
1259 	}
1260 	scsi_remove_host(shost);
1261 	dev_notice(&unit->device, "released target %d:0:0\n", shost->host_no);
1262 
1263 	scsi_host_put(shost);
1264 }
1265 
1266 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
1267 #define SBP2_SW_VERSION_ENTRY	0x00010483
1268 
1269 static const struct ieee1394_device_id sbp2_id_table[] = {
1270 	{
1271 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1272 				IEEE1394_MATCH_VERSION,
1273 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1274 		.version      = SBP2_SW_VERSION_ENTRY,
1275 	},
1276 	{ }
1277 };
1278 
1279 static struct fw_driver sbp2_driver = {
1280 	.driver   = {
1281 		.owner  = THIS_MODULE,
1282 		.name   = KBUILD_MODNAME,
1283 		.bus    = &fw_bus_type,
1284 	},
1285 	.probe    = sbp2_probe,
1286 	.update   = sbp2_update,
1287 	.remove   = sbp2_remove,
1288 	.id_table = sbp2_id_table,
1289 };
1290 
1291 static void sbp2_unmap_scatterlist(struct device *card_device,
1292 				   struct sbp2_command_orb *orb)
1293 {
1294 	scsi_dma_unmap(orb->cmd);
1295 
1296 	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1297 		dma_unmap_single(card_device, orb->page_table_bus,
1298 				 sizeof(orb->page_table), DMA_TO_DEVICE);
1299 }
1300 
1301 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1302 {
1303 	int sam_status;
1304 	int sfmt = (sbp2_status[0] >> 6) & 0x03;
1305 
1306 	if (sfmt == 2 || sfmt == 3) {
1307 		/*
1308 		 * Reserved for future standardization (2) or
1309 		 * Status block format vendor-dependent (3)
1310 		 */
1311 		return DID_ERROR << 16;
1312 	}
1313 
1314 	sense_data[0] = 0x70 | sfmt | (sbp2_status[1] & 0x80);
1315 	sense_data[1] = 0x0;
1316 	sense_data[2] = ((sbp2_status[1] << 1) & 0xe0) | (sbp2_status[1] & 0x0f);
1317 	sense_data[3] = sbp2_status[4];
1318 	sense_data[4] = sbp2_status[5];
1319 	sense_data[5] = sbp2_status[6];
1320 	sense_data[6] = sbp2_status[7];
1321 	sense_data[7] = 10;
1322 	sense_data[8] = sbp2_status[8];
1323 	sense_data[9] = sbp2_status[9];
1324 	sense_data[10] = sbp2_status[10];
1325 	sense_data[11] = sbp2_status[11];
1326 	sense_data[12] = sbp2_status[2];
1327 	sense_data[13] = sbp2_status[3];
1328 	sense_data[14] = sbp2_status[12];
1329 	sense_data[15] = sbp2_status[13];
1330 
1331 	sam_status = sbp2_status[0] & 0x3f;
1332 
1333 	switch (sam_status) {
1334 	case SAM_STAT_GOOD:
1335 	case SAM_STAT_CHECK_CONDITION:
1336 	case SAM_STAT_CONDITION_MET:
1337 	case SAM_STAT_BUSY:
1338 	case SAM_STAT_RESERVATION_CONFLICT:
1339 	case SAM_STAT_COMMAND_TERMINATED:
1340 		return DID_OK << 16 | sam_status;
1341 
1342 	default:
1343 		return DID_ERROR << 16;
1344 	}
1345 }
1346 
1347 static void complete_command_orb(struct sbp2_orb *base_orb,
1348 				 struct sbp2_status *status)
1349 {
1350 	struct sbp2_command_orb *orb =
1351 		container_of(base_orb, struct sbp2_command_orb, base);
1352 	struct fw_device *device = target_parent_device(base_orb->lu->tgt);
1353 	int result;
1354 
1355 	if (status != NULL) {
1356 		if (STATUS_GET_DEAD(*status))
1357 			sbp2_agent_reset_no_wait(base_orb->lu);
1358 
1359 		switch (STATUS_GET_RESPONSE(*status)) {
1360 		case SBP2_STATUS_REQUEST_COMPLETE:
1361 			result = DID_OK << 16;
1362 			break;
1363 		case SBP2_STATUS_TRANSPORT_FAILURE:
1364 			result = DID_BUS_BUSY << 16;
1365 			break;
1366 		case SBP2_STATUS_ILLEGAL_REQUEST:
1367 		case SBP2_STATUS_VENDOR_DEPENDENT:
1368 		default:
1369 			result = DID_ERROR << 16;
1370 			break;
1371 		}
1372 
1373 		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1374 			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1375 							   orb->cmd->sense_buffer);
1376 	} else {
1377 		/*
1378 		 * If the orb completes with status == NULL, something
1379 		 * went wrong, typically a bus reset happened mid-orb
1380 		 * or when sending the write (less likely).
1381 		 */
1382 		result = DID_BUS_BUSY << 16;
1383 		sbp2_conditionally_block(base_orb->lu);
1384 	}
1385 
1386 	dma_unmap_single(device->card->device, orb->base.request_bus,
1387 			 sizeof(orb->request), DMA_TO_DEVICE);
1388 	sbp2_unmap_scatterlist(device->card->device, orb);
1389 
1390 	orb->cmd->result = result;
1391 	orb->cmd->scsi_done(orb->cmd);
1392 }
1393 
1394 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1395 		struct fw_device *device, struct sbp2_logical_unit *lu)
1396 {
1397 	struct scatterlist *sg = scsi_sglist(orb->cmd);
1398 	int i, n;
1399 
1400 	n = scsi_dma_map(orb->cmd);
1401 	if (n <= 0)
1402 		goto fail;
1403 
1404 	/*
1405 	 * Handle the special case where there is only one element in
1406 	 * the scatter list by converting it to an immediate block
1407 	 * request. This is also a workaround for broken devices such
1408 	 * as the second generation iPod which doesn't support page
1409 	 * tables.
1410 	 */
1411 	if (n == 1) {
1412 		orb->request.data_descriptor.high =
1413 			cpu_to_be32(lu->tgt->address_high);
1414 		orb->request.data_descriptor.low  =
1415 			cpu_to_be32(sg_dma_address(sg));
1416 		orb->request.misc |=
1417 			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1418 		return 0;
1419 	}
1420 
1421 	for_each_sg(sg, sg, n, i) {
1422 		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1423 		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1424 	}
1425 
1426 	orb->page_table_bus =
1427 		dma_map_single(device->card->device, orb->page_table,
1428 			       sizeof(orb->page_table), DMA_TO_DEVICE);
1429 	if (dma_mapping_error(device->card->device, orb->page_table_bus))
1430 		goto fail_page_table;
1431 
1432 	/*
1433 	 * The data_descriptor pointer is the one case where we need
1434 	 * to fill in the node ID part of the address.  All other
1435 	 * pointers assume that the data referenced reside on the
1436 	 * initiator (i.e. us), but data_descriptor can refer to data
1437 	 * on other nodes so we need to put our ID in descriptor.high.
1438 	 */
1439 	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1440 	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1441 	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1442 					 COMMAND_ORB_DATA_SIZE(n));
1443 
1444 	return 0;
1445 
1446  fail_page_table:
1447 	scsi_dma_unmap(orb->cmd);
1448  fail:
1449 	return -ENOMEM;
1450 }
1451 
1452 /* SCSI stack integration */
1453 
1454 static int sbp2_scsi_queuecommand(struct Scsi_Host *shost,
1455 				  struct scsi_cmnd *cmd)
1456 {
1457 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1458 	struct fw_device *device = target_parent_device(lu->tgt);
1459 	struct sbp2_command_orb *orb;
1460 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1461 
1462 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1463 	if (orb == NULL)
1464 		return SCSI_MLQUEUE_HOST_BUSY;
1465 
1466 	/* Initialize rcode to something not RCODE_COMPLETE. */
1467 	orb->base.rcode = -1;
1468 	kref_init(&orb->base.kref);
1469 	orb->cmd = cmd;
1470 	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1471 	orb->request.misc = cpu_to_be32(
1472 		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1473 		COMMAND_ORB_SPEED(device->max_speed) |
1474 		COMMAND_ORB_NOTIFY);
1475 
1476 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1477 		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1478 
1479 	generation = device->generation;
1480 	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1481 
1482 	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1483 		goto out;
1484 
1485 	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1486 
1487 	orb->base.callback = complete_command_orb;
1488 	orb->base.request_bus =
1489 		dma_map_single(device->card->device, &orb->request,
1490 			       sizeof(orb->request), DMA_TO_DEVICE);
1491 	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1492 		sbp2_unmap_scatterlist(device->card->device, orb);
1493 		goto out;
1494 	}
1495 
1496 	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1497 		      lu->command_block_agent_address + SBP2_ORB_POINTER);
1498 	retval = 0;
1499  out:
1500 	kref_put(&orb->base.kref, free_orb);
1501 	return retval;
1502 }
1503 
1504 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1505 {
1506 	struct sbp2_logical_unit *lu = sdev->hostdata;
1507 
1508 	/* (Re-)Adding logical units via the SCSI stack is not supported. */
1509 	if (!lu)
1510 		return -ENOSYS;
1511 
1512 	sdev->allow_restart = 1;
1513 
1514 	/*
1515 	 * SBP-2 does not require any alignment, but we set it anyway
1516 	 * for compatibility with earlier versions of this driver.
1517 	 */
1518 	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1519 
1520 	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1521 		sdev->inquiry_len = 36;
1522 
1523 	return 0;
1524 }
1525 
1526 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1527 {
1528 	struct sbp2_logical_unit *lu = sdev->hostdata;
1529 
1530 	sdev->use_10_for_rw = 1;
1531 
1532 	if (sbp2_param_exclusive_login)
1533 		sdev->manage_start_stop = 1;
1534 
1535 	if (sdev->type == TYPE_ROM)
1536 		sdev->use_10_for_ms = 1;
1537 
1538 	if (sdev->type == TYPE_DISK &&
1539 	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1540 		sdev->skip_ms_page_8 = 1;
1541 
1542 	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1543 		sdev->fix_capacity = 1;
1544 
1545 	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1546 		sdev->start_stop_pwr_cond = 1;
1547 
1548 	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1549 		blk_queue_max_hw_sectors(sdev->request_queue, 128 * 1024 / 512);
1550 
1551 	return 0;
1552 }
1553 
1554 /*
1555  * Called by scsi stack when something has really gone wrong.  Usually
1556  * called when a command has timed-out for some reason.
1557  */
1558 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1559 {
1560 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1561 
1562 	dev_notice(lu_dev(lu), "sbp2_scsi_abort\n");
1563 	sbp2_agent_reset(lu);
1564 	sbp2_cancel_orbs(lu);
1565 
1566 	return SUCCESS;
1567 }
1568 
1569 /*
1570  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1571  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1572  *
1573  * This is the concatenation of target port identifier and logical unit
1574  * identifier as per SAM-2...SAM-4 annex A.
1575  */
1576 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1577 			struct device_attribute *attr, char *buf)
1578 {
1579 	struct scsi_device *sdev = to_scsi_device(dev);
1580 	struct sbp2_logical_unit *lu;
1581 
1582 	if (!sdev)
1583 		return 0;
1584 
1585 	lu = sdev->hostdata;
1586 
1587 	return sprintf(buf, "%016llx:%06x:%04x\n",
1588 			(unsigned long long)lu->tgt->guid,
1589 			lu->tgt->directory_id, lu->lun);
1590 }
1591 
1592 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1593 
1594 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1595 	&dev_attr_ieee1394_id,
1596 	NULL
1597 };
1598 
1599 static struct scsi_host_template scsi_driver_template = {
1600 	.module			= THIS_MODULE,
1601 	.name			= "SBP-2 IEEE-1394",
1602 	.proc_name		= "sbp2",
1603 	.queuecommand		= sbp2_scsi_queuecommand,
1604 	.slave_alloc		= sbp2_scsi_slave_alloc,
1605 	.slave_configure	= sbp2_scsi_slave_configure,
1606 	.eh_abort_handler	= sbp2_scsi_abort,
1607 	.this_id		= -1,
1608 	.sg_tablesize		= SG_ALL,
1609 	.max_segment_size	= SBP2_MAX_SEG_SIZE,
1610 	.can_queue		= 1,
1611 	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
1612 };
1613 
1614 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1615 MODULE_DESCRIPTION("SCSI over IEEE1394");
1616 MODULE_LICENSE("GPL");
1617 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1618 
1619 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1620 MODULE_ALIAS("sbp2");
1621 
1622 static int __init sbp2_init(void)
1623 {
1624 	return driver_register(&sbp2_driver.driver);
1625 }
1626 
1627 static void __exit sbp2_cleanup(void)
1628 {
1629 	driver_unregister(&sbp2_driver.driver);
1630 }
1631 
1632 module_init(sbp2_init);
1633 module_exit(sbp2_cleanup);
1634