xref: /openbmc/linux/drivers/firewire/sbp2.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SBP2 driver (SCSI over IEEE1394)
4  *
5  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
6  */
7 
8 /*
9  * The basic structure of this driver is based on the old storage driver,
10  * drivers/ieee1394/sbp2.c, originally written by
11  *     James Goodwin <jamesg@filanet.com>
12  * with later contributions and ongoing maintenance from
13  *     Ben Collins <bcollins@debian.org>,
14  *     Stefan Richter <stefanr@s5r6.in-berlin.de>
15  * and many others.
16  */
17 
18 #include <linux/blkdev.h>
19 #include <linux/bug.h>
20 #include <linux/completion.h>
21 #include <linux/delay.h>
22 #include <linux/device.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/firewire.h>
25 #include <linux/firewire-constants.h>
26 #include <linux/init.h>
27 #include <linux/jiffies.h>
28 #include <linux/kernel.h>
29 #include <linux/kref.h>
30 #include <linux/list.h>
31 #include <linux/mod_devicetable.h>
32 #include <linux/module.h>
33 #include <linux/moduleparam.h>
34 #include <linux/scatterlist.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <linux/string.h>
38 #include <linux/stringify.h>
39 #include <linux/workqueue.h>
40 
41 #include <asm/byteorder.h>
42 
43 #include <scsi/scsi.h>
44 #include <scsi/scsi_cmnd.h>
45 #include <scsi/scsi_device.h>
46 #include <scsi/scsi_host.h>
47 
48 /*
49  * So far only bridges from Oxford Semiconductor are known to support
50  * concurrent logins. Depending on firmware, four or two concurrent logins
51  * are possible on OXFW911 and newer Oxsemi bridges.
52  *
53  * Concurrent logins are useful together with cluster filesystems.
54  */
55 static bool sbp2_param_exclusive_login = 1;
56 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
57 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
58 		 "(default = Y, use N for concurrent initiators)");
59 
60 /*
61  * Flags for firmware oddities
62  *
63  * - 128kB max transfer
64  *   Limit transfer size. Necessary for some old bridges.
65  *
66  * - 36 byte inquiry
67  *   When scsi_mod probes the device, let the inquiry command look like that
68  *   from MS Windows.
69  *
70  * - skip mode page 8
71  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
72  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
73  *
74  * - fix capacity
75  *   Tell sd_mod to correct the last sector number reported by read_capacity.
76  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
77  *   Don't use this with devices which don't have this bug.
78  *
79  * - delay inquiry
80  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
81  *
82  * - power condition
83  *   Set the power condition field in the START STOP UNIT commands sent by
84  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
85  *   Some disks need this to spin down or to resume properly.
86  *
87  * - override internal blacklist
88  *   Instead of adding to the built-in blacklist, use only the workarounds
89  *   specified in the module load parameter.
90  *   Useful if a blacklist entry interfered with a non-broken device.
91  */
92 #define SBP2_WORKAROUND_128K_MAX_TRANS	0x1
93 #define SBP2_WORKAROUND_INQUIRY_36	0x2
94 #define SBP2_WORKAROUND_MODE_SENSE_8	0x4
95 #define SBP2_WORKAROUND_FIX_CAPACITY	0x8
96 #define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
97 #define SBP2_INQUIRY_DELAY		12
98 #define SBP2_WORKAROUND_POWER_CONDITION	0x20
99 #define SBP2_WORKAROUND_OVERRIDE	0x100
100 
101 static int sbp2_param_workarounds;
102 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
103 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
104 	", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
105 	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
106 	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
107 	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
108 	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
109 	", set power condition in start stop unit = "
110 				  __stringify(SBP2_WORKAROUND_POWER_CONDITION)
111 	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
112 	", or a combination)");
113 
114 /*
115  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
116  * and one struct scsi_device per sbp2_logical_unit.
117  */
118 struct sbp2_logical_unit {
119 	struct sbp2_target *tgt;
120 	struct list_head link;
121 	struct fw_address_handler address_handler;
122 	struct list_head orb_list;
123 
124 	u64 command_block_agent_address;
125 	u16 lun;
126 	int login_id;
127 
128 	/*
129 	 * The generation is updated once we've logged in or reconnected
130 	 * to the logical unit.  Thus, I/O to the device will automatically
131 	 * fail and get retried if it happens in a window where the device
132 	 * is not ready, e.g. after a bus reset but before we reconnect.
133 	 */
134 	int generation;
135 	int retries;
136 	work_func_t workfn;
137 	struct delayed_work work;
138 	bool has_sdev;
139 	bool blocked;
140 };
141 
142 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
143 {
144 	queue_delayed_work(fw_workqueue, &lu->work, delay);
145 }
146 
147 /*
148  * We create one struct sbp2_target per IEEE 1212 Unit Directory
149  * and one struct Scsi_Host per sbp2_target.
150  */
151 struct sbp2_target {
152 	struct fw_unit *unit;
153 	struct list_head lu_list;
154 
155 	u64 management_agent_address;
156 	u64 guid;
157 	int directory_id;
158 	int node_id;
159 	int address_high;
160 	unsigned int workarounds;
161 	unsigned int mgt_orb_timeout;
162 	unsigned int max_payload;
163 
164 	spinlock_t lock;
165 	int dont_block;	/* counter for each logical unit */
166 	int blocked;	/* ditto */
167 };
168 
169 static struct fw_device *target_parent_device(struct sbp2_target *tgt)
170 {
171 	return fw_parent_device(tgt->unit);
172 }
173 
174 static const struct device *tgt_dev(const struct sbp2_target *tgt)
175 {
176 	return &tgt->unit->device;
177 }
178 
179 static const struct device *lu_dev(const struct sbp2_logical_unit *lu)
180 {
181 	return &lu->tgt->unit->device;
182 }
183 
184 /* Impossible login_id, to detect logout attempt before successful login */
185 #define INVALID_LOGIN_ID 0x10000
186 
187 #define SBP2_ORB_TIMEOUT		2000U		/* Timeout in ms */
188 #define SBP2_ORB_NULL			0x80000000
189 #define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
190 #define SBP2_CYCLE_LIMIT		(0xc8 << 12)	/* 200 125us cycles */
191 
192 /*
193  * There is no transport protocol limit to the CDB length,  but we implement
194  * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
195  */
196 #define SBP2_MAX_CDB_SIZE		16
197 
198 /*
199  * The maximum SBP-2 data buffer size is 0xffff.  We quadlet-align this
200  * for compatibility with earlier versions of this driver.
201  */
202 #define SBP2_MAX_SEG_SIZE		0xfffc
203 
204 /* Unit directory keys */
205 #define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
206 #define SBP2_CSR_FIRMWARE_REVISION	0x3c
207 #define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
208 #define SBP2_CSR_UNIT_UNIQUE_ID		0x8d
209 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4
210 
211 /* Management orb opcodes */
212 #define SBP2_LOGIN_REQUEST		0x0
213 #define SBP2_QUERY_LOGINS_REQUEST	0x1
214 #define SBP2_RECONNECT_REQUEST		0x3
215 #define SBP2_SET_PASSWORD_REQUEST	0x4
216 #define SBP2_LOGOUT_REQUEST		0x7
217 #define SBP2_ABORT_TASK_REQUEST		0xb
218 #define SBP2_ABORT_TASK_SET		0xc
219 #define SBP2_LOGICAL_UNIT_RESET		0xe
220 #define SBP2_TARGET_RESET_REQUEST	0xf
221 
222 /* Offsets for command block agent registers */
223 #define SBP2_AGENT_STATE		0x00
224 #define SBP2_AGENT_RESET		0x04
225 #define SBP2_ORB_POINTER		0x08
226 #define SBP2_DOORBELL			0x10
227 #define SBP2_UNSOLICITED_STATUS_ENABLE	0x14
228 
229 /* Status write response codes */
230 #define SBP2_STATUS_REQUEST_COMPLETE	0x0
231 #define SBP2_STATUS_TRANSPORT_FAILURE	0x1
232 #define SBP2_STATUS_ILLEGAL_REQUEST	0x2
233 #define SBP2_STATUS_VENDOR_DEPENDENT	0x3
234 
235 #define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
236 #define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
237 #define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
238 #define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
239 #define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
240 #define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
241 #define STATUS_GET_ORB_LOW(v)		((v).orb_low)
242 #define STATUS_GET_DATA(v)		((v).data)
243 
244 struct sbp2_status {
245 	u32 status;
246 	u32 orb_low;
247 	u8 data[24];
248 };
249 
250 struct sbp2_pointer {
251 	__be32 high;
252 	__be32 low;
253 };
254 
255 struct sbp2_orb {
256 	struct fw_transaction t;
257 	struct kref kref;
258 	dma_addr_t request_bus;
259 	int rcode;
260 	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
261 	struct sbp2_logical_unit *lu;
262 	struct list_head link;
263 };
264 
265 #define MANAGEMENT_ORB_LUN(v)			((v))
266 #define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
267 #define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
268 #define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
269 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
270 #define MANAGEMENT_ORB_NOTIFY			((1) << 31)
271 
272 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
273 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
274 
275 struct sbp2_management_orb {
276 	struct sbp2_orb base;
277 	struct {
278 		struct sbp2_pointer password;
279 		struct sbp2_pointer response;
280 		__be32 misc;
281 		__be32 length;
282 		struct sbp2_pointer status_fifo;
283 	} request;
284 	__be32 response[4];
285 	dma_addr_t response_bus;
286 	struct completion done;
287 	struct sbp2_status status;
288 };
289 
290 struct sbp2_login_response {
291 	__be32 misc;
292 	struct sbp2_pointer command_block_agent;
293 	__be32 reconnect_hold;
294 };
295 #define COMMAND_ORB_DATA_SIZE(v)	((v))
296 #define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
297 #define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
298 #define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
299 #define COMMAND_ORB_SPEED(v)		((v) << 24)
300 #define COMMAND_ORB_DIRECTION		((1) << 27)
301 #define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
302 #define COMMAND_ORB_NOTIFY		((1) << 31)
303 
304 struct sbp2_command_orb {
305 	struct sbp2_orb base;
306 	struct {
307 		struct sbp2_pointer next;
308 		struct sbp2_pointer data_descriptor;
309 		__be32 misc;
310 		u8 command_block[SBP2_MAX_CDB_SIZE];
311 	} request;
312 	struct scsi_cmnd *cmd;
313 
314 	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
315 	dma_addr_t page_table_bus;
316 };
317 
318 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
319 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
320 
321 /*
322  * List of devices with known bugs.
323  *
324  * The firmware_revision field, masked with 0xffff00, is the best
325  * indicator for the type of bridge chip of a device.  It yields a few
326  * false positives but this did not break correctly behaving devices
327  * so far.
328  */
329 static const struct {
330 	u32 firmware_revision;
331 	u32 model;
332 	unsigned int workarounds;
333 } sbp2_workarounds_table[] = {
334 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
335 		.firmware_revision	= 0x002800,
336 		.model			= 0x001010,
337 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
338 					  SBP2_WORKAROUND_MODE_SENSE_8 |
339 					  SBP2_WORKAROUND_POWER_CONDITION,
340 	},
341 	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
342 		.firmware_revision	= 0x002800,
343 		.model			= 0x000000,
344 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
345 	},
346 	/* Initio bridges, actually only needed for some older ones */ {
347 		.firmware_revision	= 0x000200,
348 		.model			= SBP2_ROM_VALUE_WILDCARD,
349 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
350 	},
351 	/* PL-3507 bridge with Prolific firmware */ {
352 		.firmware_revision	= 0x012800,
353 		.model			= SBP2_ROM_VALUE_WILDCARD,
354 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
355 	},
356 	/* Symbios bridge */ {
357 		.firmware_revision	= 0xa0b800,
358 		.model			= SBP2_ROM_VALUE_WILDCARD,
359 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
360 	},
361 	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
362 		.firmware_revision	= 0x002600,
363 		.model			= SBP2_ROM_VALUE_WILDCARD,
364 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
365 	},
366 	/*
367 	 * iPod 2nd generation: needs 128k max transfer size workaround
368 	 * iPod 3rd generation: needs fix capacity workaround
369 	 */
370 	{
371 		.firmware_revision	= 0x0a2700,
372 		.model			= 0x000000,
373 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
374 					  SBP2_WORKAROUND_FIX_CAPACITY,
375 	},
376 	/* iPod 4th generation */ {
377 		.firmware_revision	= 0x0a2700,
378 		.model			= 0x000021,
379 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
380 	},
381 	/* iPod mini */ {
382 		.firmware_revision	= 0x0a2700,
383 		.model			= 0x000022,
384 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
385 	},
386 	/* iPod mini */ {
387 		.firmware_revision	= 0x0a2700,
388 		.model			= 0x000023,
389 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
390 	},
391 	/* iPod Photo */ {
392 		.firmware_revision	= 0x0a2700,
393 		.model			= 0x00007e,
394 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
395 	}
396 };
397 
398 static void free_orb(struct kref *kref)
399 {
400 	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
401 
402 	kfree(orb);
403 }
404 
405 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
406 			      int tcode, int destination, int source,
407 			      int generation, unsigned long long offset,
408 			      void *payload, size_t length, void *callback_data)
409 {
410 	struct sbp2_logical_unit *lu = callback_data;
411 	struct sbp2_orb *orb;
412 	struct sbp2_status status;
413 	unsigned long flags;
414 
415 	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
416 	    length < 8 || length > sizeof(status)) {
417 		fw_send_response(card, request, RCODE_TYPE_ERROR);
418 		return;
419 	}
420 
421 	status.status  = be32_to_cpup(payload);
422 	status.orb_low = be32_to_cpup(payload + 4);
423 	memset(status.data, 0, sizeof(status.data));
424 	if (length > 8)
425 		memcpy(status.data, payload + 8, length - 8);
426 
427 	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
428 		dev_notice(lu_dev(lu),
429 			   "non-ORB related status write, not handled\n");
430 		fw_send_response(card, request, RCODE_COMPLETE);
431 		return;
432 	}
433 
434 	/* Lookup the orb corresponding to this status write. */
435 	spin_lock_irqsave(&lu->tgt->lock, flags);
436 	list_for_each_entry(orb, &lu->orb_list, link) {
437 		if (STATUS_GET_ORB_HIGH(status) == 0 &&
438 		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
439 			orb->rcode = RCODE_COMPLETE;
440 			list_del(&orb->link);
441 			break;
442 		}
443 	}
444 	spin_unlock_irqrestore(&lu->tgt->lock, flags);
445 
446 	if (&orb->link != &lu->orb_list) {
447 		orb->callback(orb, &status);
448 		kref_put(&orb->kref, free_orb); /* orb callback reference */
449 	} else {
450 		dev_err(lu_dev(lu), "status write for unknown ORB\n");
451 	}
452 
453 	fw_send_response(card, request, RCODE_COMPLETE);
454 }
455 
456 static void complete_transaction(struct fw_card *card, int rcode,
457 				 void *payload, size_t length, void *data)
458 {
459 	struct sbp2_orb *orb = data;
460 	unsigned long flags;
461 
462 	/*
463 	 * This is a little tricky.  We can get the status write for
464 	 * the orb before we get this callback.  The status write
465 	 * handler above will assume the orb pointer transaction was
466 	 * successful and set the rcode to RCODE_COMPLETE for the orb.
467 	 * So this callback only sets the rcode if it hasn't already
468 	 * been set and only does the cleanup if the transaction
469 	 * failed and we didn't already get a status write.
470 	 */
471 	spin_lock_irqsave(&orb->lu->tgt->lock, flags);
472 
473 	if (orb->rcode == -1)
474 		orb->rcode = rcode;
475 	if (orb->rcode != RCODE_COMPLETE) {
476 		list_del(&orb->link);
477 		spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
478 
479 		orb->callback(orb, NULL);
480 		kref_put(&orb->kref, free_orb); /* orb callback reference */
481 	} else {
482 		spin_unlock_irqrestore(&orb->lu->tgt->lock, flags);
483 	}
484 
485 	kref_put(&orb->kref, free_orb); /* transaction callback reference */
486 }
487 
488 static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
489 			  int node_id, int generation, u64 offset)
490 {
491 	struct fw_device *device = target_parent_device(lu->tgt);
492 	struct sbp2_pointer orb_pointer;
493 	unsigned long flags;
494 
495 	orb_pointer.high = 0;
496 	orb_pointer.low = cpu_to_be32(orb->request_bus);
497 
498 	orb->lu = lu;
499 	spin_lock_irqsave(&lu->tgt->lock, flags);
500 	list_add_tail(&orb->link, &lu->orb_list);
501 	spin_unlock_irqrestore(&lu->tgt->lock, flags);
502 
503 	kref_get(&orb->kref); /* transaction callback reference */
504 	kref_get(&orb->kref); /* orb callback reference */
505 
506 	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
507 			node_id, generation, device->max_speed, offset,
508 			&orb_pointer, 8, complete_transaction, orb);
509 }
510 
511 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
512 {
513 	struct fw_device *device = target_parent_device(lu->tgt);
514 	struct sbp2_orb *orb, *next;
515 	struct list_head list;
516 	int retval = -ENOENT;
517 
518 	INIT_LIST_HEAD(&list);
519 	spin_lock_irq(&lu->tgt->lock);
520 	list_splice_init(&lu->orb_list, &list);
521 	spin_unlock_irq(&lu->tgt->lock);
522 
523 	list_for_each_entry_safe(orb, next, &list, link) {
524 		retval = 0;
525 		if (fw_cancel_transaction(device->card, &orb->t) == 0)
526 			continue;
527 
528 		orb->rcode = RCODE_CANCELLED;
529 		orb->callback(orb, NULL);
530 		kref_put(&orb->kref, free_orb); /* orb callback reference */
531 	}
532 
533 	return retval;
534 }
535 
536 static void complete_management_orb(struct sbp2_orb *base_orb,
537 				    struct sbp2_status *status)
538 {
539 	struct sbp2_management_orb *orb =
540 		container_of(base_orb, struct sbp2_management_orb, base);
541 
542 	if (status)
543 		memcpy(&orb->status, status, sizeof(*status));
544 	complete(&orb->done);
545 }
546 
547 static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
548 				    int generation, int function,
549 				    int lun_or_login_id, void *response)
550 {
551 	struct fw_device *device = target_parent_device(lu->tgt);
552 	struct sbp2_management_orb *orb;
553 	unsigned int timeout;
554 	int retval = -ENOMEM;
555 
556 	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
557 		return 0;
558 
559 	orb = kzalloc(sizeof(*orb), GFP_NOIO);
560 	if (orb == NULL)
561 		return -ENOMEM;
562 
563 	kref_init(&orb->base.kref);
564 	orb->response_bus =
565 		dma_map_single(device->card->device, &orb->response,
566 			       sizeof(orb->response), DMA_FROM_DEVICE);
567 	if (dma_mapping_error(device->card->device, orb->response_bus))
568 		goto fail_mapping_response;
569 
570 	orb->request.response.high = 0;
571 	orb->request.response.low  = cpu_to_be32(orb->response_bus);
572 
573 	orb->request.misc = cpu_to_be32(
574 		MANAGEMENT_ORB_NOTIFY |
575 		MANAGEMENT_ORB_FUNCTION(function) |
576 		MANAGEMENT_ORB_LUN(lun_or_login_id));
577 	orb->request.length = cpu_to_be32(
578 		MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
579 
580 	orb->request.status_fifo.high =
581 		cpu_to_be32(lu->address_handler.offset >> 32);
582 	orb->request.status_fifo.low  =
583 		cpu_to_be32(lu->address_handler.offset);
584 
585 	if (function == SBP2_LOGIN_REQUEST) {
586 		/* Ask for 2^2 == 4 seconds reconnect grace period */
587 		orb->request.misc |= cpu_to_be32(
588 			MANAGEMENT_ORB_RECONNECT(2) |
589 			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
590 		timeout = lu->tgt->mgt_orb_timeout;
591 	} else {
592 		timeout = SBP2_ORB_TIMEOUT;
593 	}
594 
595 	init_completion(&orb->done);
596 	orb->base.callback = complete_management_orb;
597 
598 	orb->base.request_bus =
599 		dma_map_single(device->card->device, &orb->request,
600 			       sizeof(orb->request), DMA_TO_DEVICE);
601 	if (dma_mapping_error(device->card->device, orb->base.request_bus))
602 		goto fail_mapping_request;
603 
604 	sbp2_send_orb(&orb->base, lu, node_id, generation,
605 		      lu->tgt->management_agent_address);
606 
607 	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
608 
609 	retval = -EIO;
610 	if (sbp2_cancel_orbs(lu) == 0) {
611 		dev_err(lu_dev(lu), "ORB reply timed out, rcode 0x%02x\n",
612 			orb->base.rcode);
613 		goto out;
614 	}
615 
616 	if (orb->base.rcode != RCODE_COMPLETE) {
617 		dev_err(lu_dev(lu), "management write failed, rcode 0x%02x\n",
618 			orb->base.rcode);
619 		goto out;
620 	}
621 
622 	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
623 	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
624 		dev_err(lu_dev(lu), "error status: %d:%d\n",
625 			 STATUS_GET_RESPONSE(orb->status),
626 			 STATUS_GET_SBP_STATUS(orb->status));
627 		goto out;
628 	}
629 
630 	retval = 0;
631  out:
632 	dma_unmap_single(device->card->device, orb->base.request_bus,
633 			 sizeof(orb->request), DMA_TO_DEVICE);
634  fail_mapping_request:
635 	dma_unmap_single(device->card->device, orb->response_bus,
636 			 sizeof(orb->response), DMA_FROM_DEVICE);
637  fail_mapping_response:
638 	if (response)
639 		memcpy(response, orb->response, sizeof(orb->response));
640 	kref_put(&orb->base.kref, free_orb);
641 
642 	return retval;
643 }
644 
645 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
646 {
647 	struct fw_device *device = target_parent_device(lu->tgt);
648 	__be32 d = 0;
649 
650 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
651 			   lu->tgt->node_id, lu->generation, device->max_speed,
652 			   lu->command_block_agent_address + SBP2_AGENT_RESET,
653 			   &d, 4);
654 }
655 
656 static void complete_agent_reset_write_no_wait(struct fw_card *card,
657 		int rcode, void *payload, size_t length, void *data)
658 {
659 	kfree(data);
660 }
661 
662 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
663 {
664 	struct fw_device *device = target_parent_device(lu->tgt);
665 	struct fw_transaction *t;
666 	static __be32 d;
667 
668 	t = kmalloc(sizeof(*t), GFP_ATOMIC);
669 	if (t == NULL)
670 		return;
671 
672 	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
673 			lu->tgt->node_id, lu->generation, device->max_speed,
674 			lu->command_block_agent_address + SBP2_AGENT_RESET,
675 			&d, 4, complete_agent_reset_write_no_wait, t);
676 }
677 
678 static inline void sbp2_allow_block(struct sbp2_target *tgt)
679 {
680 	spin_lock_irq(&tgt->lock);
681 	--tgt->dont_block;
682 	spin_unlock_irq(&tgt->lock);
683 }
684 
685 /*
686  * Blocks lu->tgt if all of the following conditions are met:
687  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
688  *     logical units have been finished (indicated by dont_block == 0).
689  *   - lu->generation is stale.
690  *
691  * Note, scsi_block_requests() must be called while holding tgt->lock,
692  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
693  * unblock the target.
694  */
695 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
696 {
697 	struct sbp2_target *tgt = lu->tgt;
698 	struct fw_card *card = target_parent_device(tgt)->card;
699 	struct Scsi_Host *shost =
700 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
701 	unsigned long flags;
702 
703 	spin_lock_irqsave(&tgt->lock, flags);
704 	if (!tgt->dont_block && !lu->blocked &&
705 	    lu->generation != card->generation) {
706 		lu->blocked = true;
707 		if (++tgt->blocked == 1)
708 			scsi_block_requests(shost);
709 	}
710 	spin_unlock_irqrestore(&tgt->lock, flags);
711 }
712 
713 /*
714  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
715  * Note, it is harmless to run scsi_unblock_requests() outside the
716  * tgt->lock protected section.  On the other hand, running it inside
717  * the section might clash with shost->host_lock.
718  */
719 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
720 {
721 	struct sbp2_target *tgt = lu->tgt;
722 	struct fw_card *card = target_parent_device(tgt)->card;
723 	struct Scsi_Host *shost =
724 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
725 	bool unblock = false;
726 
727 	spin_lock_irq(&tgt->lock);
728 	if (lu->blocked && lu->generation == card->generation) {
729 		lu->blocked = false;
730 		unblock = --tgt->blocked == 0;
731 	}
732 	spin_unlock_irq(&tgt->lock);
733 
734 	if (unblock)
735 		scsi_unblock_requests(shost);
736 }
737 
738 /*
739  * Prevents future blocking of tgt and unblocks it.
740  * Note, it is harmless to run scsi_unblock_requests() outside the
741  * tgt->lock protected section.  On the other hand, running it inside
742  * the section might clash with shost->host_lock.
743  */
744 static void sbp2_unblock(struct sbp2_target *tgt)
745 {
746 	struct Scsi_Host *shost =
747 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
748 
749 	spin_lock_irq(&tgt->lock);
750 	++tgt->dont_block;
751 	spin_unlock_irq(&tgt->lock);
752 
753 	scsi_unblock_requests(shost);
754 }
755 
756 static int sbp2_lun2int(u16 lun)
757 {
758 	struct scsi_lun eight_bytes_lun;
759 
760 	memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
761 	eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
762 	eight_bytes_lun.scsi_lun[1] = lun & 0xff;
763 
764 	return scsilun_to_int(&eight_bytes_lun);
765 }
766 
767 /*
768  * Write retransmit retry values into the BUSY_TIMEOUT register.
769  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
770  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
771  *   saner value after logging into the device.
772  * - The dual-phase retry protocol is optional to implement, and if not
773  *   supported, writes to the dual-phase portion of the register will be
774  *   ignored. We try to write the original 1394-1995 default here.
775  * - In the case of devices that are also SBP-3-compliant, all writes are
776  *   ignored, as the register is read-only, but contains single-phase retry of
777  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
778  *   write attempt is safe and yields more consistent behavior for all devices.
779  *
780  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
781  * and section 6.4 of the SBP-3 spec for further details.
782  */
783 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
784 {
785 	struct fw_device *device = target_parent_device(lu->tgt);
786 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
787 
788 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
789 			   lu->tgt->node_id, lu->generation, device->max_speed,
790 			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &d, 4);
791 }
792 
793 static void sbp2_reconnect(struct work_struct *work);
794 
795 static void sbp2_login(struct work_struct *work)
796 {
797 	struct sbp2_logical_unit *lu =
798 		container_of(work, struct sbp2_logical_unit, work.work);
799 	struct sbp2_target *tgt = lu->tgt;
800 	struct fw_device *device = target_parent_device(tgt);
801 	struct Scsi_Host *shost;
802 	struct scsi_device *sdev;
803 	struct sbp2_login_response response;
804 	int generation, node_id, local_node_id;
805 
806 	if (fw_device_is_shutdown(device))
807 		return;
808 
809 	generation    = device->generation;
810 	smp_rmb();    /* node IDs must not be older than generation */
811 	node_id       = device->node_id;
812 	local_node_id = device->card->node_id;
813 
814 	/* If this is a re-login attempt, log out, or we might be rejected. */
815 	if (lu->has_sdev)
816 		sbp2_send_management_orb(lu, device->node_id, generation,
817 				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
818 
819 	if (sbp2_send_management_orb(lu, node_id, generation,
820 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
821 		if (lu->retries++ < 5) {
822 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
823 		} else {
824 			dev_err(tgt_dev(tgt), "failed to login to LUN %04x\n",
825 				lu->lun);
826 			/* Let any waiting I/O fail from now on. */
827 			sbp2_unblock(lu->tgt);
828 		}
829 		return;
830 	}
831 
832 	tgt->node_id	  = node_id;
833 	tgt->address_high = local_node_id << 16;
834 	smp_wmb();	  /* node IDs must not be older than generation */
835 	lu->generation	  = generation;
836 
837 	lu->command_block_agent_address =
838 		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
839 		      << 32) | be32_to_cpu(response.command_block_agent.low);
840 	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
841 
842 	dev_notice(tgt_dev(tgt), "logged in to LUN %04x (%d retries)\n",
843 		   lu->lun, lu->retries);
844 
845 	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
846 	sbp2_set_busy_timeout(lu);
847 
848 	lu->workfn = sbp2_reconnect;
849 	sbp2_agent_reset(lu);
850 
851 	/* This was a re-login. */
852 	if (lu->has_sdev) {
853 		sbp2_cancel_orbs(lu);
854 		sbp2_conditionally_unblock(lu);
855 
856 		return;
857 	}
858 
859 	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
860 		ssleep(SBP2_INQUIRY_DELAY);
861 
862 	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
863 	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
864 	/*
865 	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
866 	 * Therefore __scsi_add_device() will get into trouble if a bus reset
867 	 * happens in parallel.  It will either fail or leave us with an
868 	 * unusable sdev.  As a workaround we check for this and retry the
869 	 * whole login and SCSI probing.
870 	 */
871 
872 	/* Reported error during __scsi_add_device() */
873 	if (IS_ERR(sdev))
874 		goto out_logout_login;
875 
876 	/* Unreported error during __scsi_add_device() */
877 	smp_rmb(); /* get current card generation */
878 	if (generation != device->card->generation) {
879 		scsi_remove_device(sdev);
880 		scsi_device_put(sdev);
881 		goto out_logout_login;
882 	}
883 
884 	/* No error during __scsi_add_device() */
885 	lu->has_sdev = true;
886 	scsi_device_put(sdev);
887 	sbp2_allow_block(tgt);
888 
889 	return;
890 
891  out_logout_login:
892 	smp_rmb(); /* generation may have changed */
893 	generation = device->generation;
894 	smp_rmb(); /* node_id must not be older than generation */
895 
896 	sbp2_send_management_orb(lu, device->node_id, generation,
897 				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
898 	/*
899 	 * If a bus reset happened, sbp2_update will have requeued
900 	 * lu->work already.  Reset the work from reconnect to login.
901 	 */
902 	lu->workfn = sbp2_login;
903 }
904 
905 static void sbp2_reconnect(struct work_struct *work)
906 {
907 	struct sbp2_logical_unit *lu =
908 		container_of(work, struct sbp2_logical_unit, work.work);
909 	struct sbp2_target *tgt = lu->tgt;
910 	struct fw_device *device = target_parent_device(tgt);
911 	int generation, node_id, local_node_id;
912 
913 	if (fw_device_is_shutdown(device))
914 		return;
915 
916 	generation    = device->generation;
917 	smp_rmb();    /* node IDs must not be older than generation */
918 	node_id       = device->node_id;
919 	local_node_id = device->card->node_id;
920 
921 	if (sbp2_send_management_orb(lu, node_id, generation,
922 				     SBP2_RECONNECT_REQUEST,
923 				     lu->login_id, NULL) < 0) {
924 		/*
925 		 * If reconnect was impossible even though we are in the
926 		 * current generation, fall back and try to log in again.
927 		 *
928 		 * We could check for "Function rejected" status, but
929 		 * looking at the bus generation as simpler and more general.
930 		 */
931 		smp_rmb(); /* get current card generation */
932 		if (generation == device->card->generation ||
933 		    lu->retries++ >= 5) {
934 			dev_err(tgt_dev(tgt), "failed to reconnect\n");
935 			lu->retries = 0;
936 			lu->workfn = sbp2_login;
937 		}
938 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
939 
940 		return;
941 	}
942 
943 	tgt->node_id      = node_id;
944 	tgt->address_high = local_node_id << 16;
945 	smp_wmb();	  /* node IDs must not be older than generation */
946 	lu->generation	  = generation;
947 
948 	dev_notice(tgt_dev(tgt), "reconnected to LUN %04x (%d retries)\n",
949 		   lu->lun, lu->retries);
950 
951 	sbp2_agent_reset(lu);
952 	sbp2_cancel_orbs(lu);
953 	sbp2_conditionally_unblock(lu);
954 }
955 
956 static void sbp2_lu_workfn(struct work_struct *work)
957 {
958 	struct sbp2_logical_unit *lu = container_of(to_delayed_work(work),
959 						struct sbp2_logical_unit, work);
960 	lu->workfn(work);
961 }
962 
963 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
964 {
965 	struct sbp2_logical_unit *lu;
966 
967 	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
968 	if (!lu)
969 		return -ENOMEM;
970 
971 	lu->address_handler.length           = 0x100;
972 	lu->address_handler.address_callback = sbp2_status_write;
973 	lu->address_handler.callback_data    = lu;
974 
975 	if (fw_core_add_address_handler(&lu->address_handler,
976 					&fw_high_memory_region) < 0) {
977 		kfree(lu);
978 		return -ENOMEM;
979 	}
980 
981 	lu->tgt      = tgt;
982 	lu->lun      = lun_entry & 0xffff;
983 	lu->login_id = INVALID_LOGIN_ID;
984 	lu->retries  = 0;
985 	lu->has_sdev = false;
986 	lu->blocked  = false;
987 	++tgt->dont_block;
988 	INIT_LIST_HEAD(&lu->orb_list);
989 	lu->workfn = sbp2_login;
990 	INIT_DELAYED_WORK(&lu->work, sbp2_lu_workfn);
991 
992 	list_add_tail(&lu->link, &tgt->lu_list);
993 	return 0;
994 }
995 
996 static void sbp2_get_unit_unique_id(struct sbp2_target *tgt,
997 				    const u32 *leaf)
998 {
999 	if ((leaf[0] & 0xffff0000) == 0x00020000)
1000 		tgt->guid = (u64)leaf[1] << 32 | leaf[2];
1001 }
1002 
1003 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
1004 				      const u32 *directory)
1005 {
1006 	struct fw_csr_iterator ci;
1007 	int key, value;
1008 
1009 	fw_csr_iterator_init(&ci, directory);
1010 	while (fw_csr_iterator_next(&ci, &key, &value))
1011 		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1012 		    sbp2_add_logical_unit(tgt, value) < 0)
1013 			return -ENOMEM;
1014 	return 0;
1015 }
1016 
1017 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
1018 			      u32 *model, u32 *firmware_revision)
1019 {
1020 	struct fw_csr_iterator ci;
1021 	int key, value;
1022 
1023 	fw_csr_iterator_init(&ci, directory);
1024 	while (fw_csr_iterator_next(&ci, &key, &value)) {
1025 		switch (key) {
1026 
1027 		case CSR_DEPENDENT_INFO | CSR_OFFSET:
1028 			tgt->management_agent_address =
1029 					CSR_REGISTER_BASE + 4 * value;
1030 			break;
1031 
1032 		case CSR_DIRECTORY_ID:
1033 			tgt->directory_id = value;
1034 			break;
1035 
1036 		case CSR_MODEL:
1037 			*model = value;
1038 			break;
1039 
1040 		case SBP2_CSR_FIRMWARE_REVISION:
1041 			*firmware_revision = value;
1042 			break;
1043 
1044 		case SBP2_CSR_UNIT_CHARACTERISTICS:
1045 			/* the timeout value is stored in 500ms units */
1046 			tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
1047 			break;
1048 
1049 		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1050 			if (sbp2_add_logical_unit(tgt, value) < 0)
1051 				return -ENOMEM;
1052 			break;
1053 
1054 		case SBP2_CSR_UNIT_UNIQUE_ID:
1055 			sbp2_get_unit_unique_id(tgt, ci.p - 1 + value);
1056 			break;
1057 
1058 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1059 			/* Adjust for the increment in the iterator */
1060 			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1061 				return -ENOMEM;
1062 			break;
1063 		}
1064 	}
1065 	return 0;
1066 }
1067 
1068 /*
1069  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
1070  * provided in the config rom. Most devices do provide a value, which
1071  * we'll use for login management orbs, but with some sane limits.
1072  */
1073 static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
1074 {
1075 	unsigned int timeout = tgt->mgt_orb_timeout;
1076 
1077 	if (timeout > 40000)
1078 		dev_notice(tgt_dev(tgt), "%ds mgt_ORB_timeout limited to 40s\n",
1079 			   timeout / 1000);
1080 
1081 	tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
1082 }
1083 
1084 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1085 				  u32 firmware_revision)
1086 {
1087 	int i;
1088 	unsigned int w = sbp2_param_workarounds;
1089 
1090 	if (w)
1091 		dev_notice(tgt_dev(tgt),
1092 			   "Please notify linux1394-devel@lists.sf.net "
1093 			   "if you need the workarounds parameter\n");
1094 
1095 	if (w & SBP2_WORKAROUND_OVERRIDE)
1096 		goto out;
1097 
1098 	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1099 
1100 		if (sbp2_workarounds_table[i].firmware_revision !=
1101 		    (firmware_revision & 0xffffff00))
1102 			continue;
1103 
1104 		if (sbp2_workarounds_table[i].model != model &&
1105 		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1106 			continue;
1107 
1108 		w |= sbp2_workarounds_table[i].workarounds;
1109 		break;
1110 	}
1111  out:
1112 	if (w)
1113 		dev_notice(tgt_dev(tgt), "workarounds 0x%x "
1114 			   "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1115 			   w, firmware_revision, model);
1116 	tgt->workarounds = w;
1117 }
1118 
1119 static struct scsi_host_template scsi_driver_template;
1120 static void sbp2_remove(struct fw_unit *unit);
1121 
1122 static int sbp2_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
1123 {
1124 	struct fw_device *device = fw_parent_device(unit);
1125 	struct sbp2_target *tgt;
1126 	struct sbp2_logical_unit *lu;
1127 	struct Scsi_Host *shost;
1128 	u32 model, firmware_revision;
1129 
1130 	/* cannot (or should not) handle targets on the local node */
1131 	if (device->is_local)
1132 		return -ENODEV;
1133 
1134 	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1135 	if (shost == NULL)
1136 		return -ENOMEM;
1137 
1138 	tgt = (struct sbp2_target *)shost->hostdata;
1139 	dev_set_drvdata(&unit->device, tgt);
1140 	tgt->unit = unit;
1141 	INIT_LIST_HEAD(&tgt->lu_list);
1142 	spin_lock_init(&tgt->lock);
1143 	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1144 
1145 	if (fw_device_enable_phys_dma(device) < 0)
1146 		goto fail_shost_put;
1147 
1148 	shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1149 
1150 	if (scsi_add_host_with_dma(shost, &unit->device,
1151 				   device->card->device) < 0)
1152 		goto fail_shost_put;
1153 
1154 	/* implicit directory ID */
1155 	tgt->directory_id = ((unit->directory - device->config_rom) * 4
1156 			     + CSR_CONFIG_ROM) & 0xffffff;
1157 
1158 	firmware_revision = SBP2_ROM_VALUE_MISSING;
1159 	model		  = SBP2_ROM_VALUE_MISSING;
1160 
1161 	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1162 			       &firmware_revision) < 0)
1163 		goto fail_remove;
1164 
1165 	sbp2_clamp_management_orb_timeout(tgt);
1166 	sbp2_init_workarounds(tgt, model, firmware_revision);
1167 
1168 	/*
1169 	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1170 	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
1171 	 * specifies the max payload size as 2 ^ (max_payload + 2), so
1172 	 * if we set this to max_speed + 7, we get the right value.
1173 	 */
1174 	tgt->max_payload = min3(device->max_speed + 7, 10U,
1175 				device->card->max_receive - 1);
1176 
1177 	/* Do the login in a workqueue so we can easily reschedule retries. */
1178 	list_for_each_entry(lu, &tgt->lu_list, link)
1179 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1180 
1181 	return 0;
1182 
1183  fail_remove:
1184 	sbp2_remove(unit);
1185 	return -ENOMEM;
1186 
1187  fail_shost_put:
1188 	scsi_host_put(shost);
1189 	return -ENOMEM;
1190 }
1191 
1192 static void sbp2_update(struct fw_unit *unit)
1193 {
1194 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1195 	struct sbp2_logical_unit *lu;
1196 
1197 	fw_device_enable_phys_dma(fw_parent_device(unit));
1198 
1199 	/*
1200 	 * Fw-core serializes sbp2_update() against sbp2_remove().
1201 	 * Iteration over tgt->lu_list is therefore safe here.
1202 	 */
1203 	list_for_each_entry(lu, &tgt->lu_list, link) {
1204 		sbp2_conditionally_block(lu);
1205 		lu->retries = 0;
1206 		sbp2_queue_work(lu, 0);
1207 	}
1208 }
1209 
1210 static void sbp2_remove(struct fw_unit *unit)
1211 {
1212 	struct fw_device *device = fw_parent_device(unit);
1213 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1214 	struct sbp2_logical_unit *lu, *next;
1215 	struct Scsi_Host *shost =
1216 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
1217 	struct scsi_device *sdev;
1218 
1219 	/* prevent deadlocks */
1220 	sbp2_unblock(tgt);
1221 
1222 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
1223 		cancel_delayed_work_sync(&lu->work);
1224 		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
1225 		if (sdev) {
1226 			scsi_remove_device(sdev);
1227 			scsi_device_put(sdev);
1228 		}
1229 		if (lu->login_id != INVALID_LOGIN_ID) {
1230 			int generation, node_id;
1231 			/*
1232 			 * tgt->node_id may be obsolete here if we failed
1233 			 * during initial login or after a bus reset where
1234 			 * the topology changed.
1235 			 */
1236 			generation = device->generation;
1237 			smp_rmb(); /* node_id vs. generation */
1238 			node_id    = device->node_id;
1239 			sbp2_send_management_orb(lu, node_id, generation,
1240 						 SBP2_LOGOUT_REQUEST,
1241 						 lu->login_id, NULL);
1242 		}
1243 		fw_core_remove_address_handler(&lu->address_handler);
1244 		list_del(&lu->link);
1245 		kfree(lu);
1246 	}
1247 	scsi_remove_host(shost);
1248 	dev_notice(&unit->device, "released target %d:0:0\n", shost->host_no);
1249 
1250 	scsi_host_put(shost);
1251 }
1252 
1253 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
1254 #define SBP2_SW_VERSION_ENTRY	0x00010483
1255 
1256 static const struct ieee1394_device_id sbp2_id_table[] = {
1257 	{
1258 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1259 				IEEE1394_MATCH_VERSION,
1260 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1261 		.version      = SBP2_SW_VERSION_ENTRY,
1262 	},
1263 	{ }
1264 };
1265 
1266 static struct fw_driver sbp2_driver = {
1267 	.driver   = {
1268 		.owner  = THIS_MODULE,
1269 		.name   = KBUILD_MODNAME,
1270 		.bus    = &fw_bus_type,
1271 	},
1272 	.probe    = sbp2_probe,
1273 	.update   = sbp2_update,
1274 	.remove   = sbp2_remove,
1275 	.id_table = sbp2_id_table,
1276 };
1277 
1278 static void sbp2_unmap_scatterlist(struct device *card_device,
1279 				   struct sbp2_command_orb *orb)
1280 {
1281 	scsi_dma_unmap(orb->cmd);
1282 
1283 	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1284 		dma_unmap_single(card_device, orb->page_table_bus,
1285 				 sizeof(orb->page_table), DMA_TO_DEVICE);
1286 }
1287 
1288 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1289 {
1290 	int sam_status;
1291 	int sfmt = (sbp2_status[0] >> 6) & 0x03;
1292 
1293 	if (sfmt == 2 || sfmt == 3) {
1294 		/*
1295 		 * Reserved for future standardization (2) or
1296 		 * Status block format vendor-dependent (3)
1297 		 */
1298 		return DID_ERROR << 16;
1299 	}
1300 
1301 	sense_data[0] = 0x70 | sfmt | (sbp2_status[1] & 0x80);
1302 	sense_data[1] = 0x0;
1303 	sense_data[2] = ((sbp2_status[1] << 1) & 0xe0) | (sbp2_status[1] & 0x0f);
1304 	sense_data[3] = sbp2_status[4];
1305 	sense_data[4] = sbp2_status[5];
1306 	sense_data[5] = sbp2_status[6];
1307 	sense_data[6] = sbp2_status[7];
1308 	sense_data[7] = 10;
1309 	sense_data[8] = sbp2_status[8];
1310 	sense_data[9] = sbp2_status[9];
1311 	sense_data[10] = sbp2_status[10];
1312 	sense_data[11] = sbp2_status[11];
1313 	sense_data[12] = sbp2_status[2];
1314 	sense_data[13] = sbp2_status[3];
1315 	sense_data[14] = sbp2_status[12];
1316 	sense_data[15] = sbp2_status[13];
1317 
1318 	sam_status = sbp2_status[0] & 0x3f;
1319 
1320 	switch (sam_status) {
1321 	case SAM_STAT_GOOD:
1322 	case SAM_STAT_CHECK_CONDITION:
1323 	case SAM_STAT_CONDITION_MET:
1324 	case SAM_STAT_BUSY:
1325 	case SAM_STAT_RESERVATION_CONFLICT:
1326 	case SAM_STAT_COMMAND_TERMINATED:
1327 		return DID_OK << 16 | sam_status;
1328 
1329 	default:
1330 		return DID_ERROR << 16;
1331 	}
1332 }
1333 
1334 static void complete_command_orb(struct sbp2_orb *base_orb,
1335 				 struct sbp2_status *status)
1336 {
1337 	struct sbp2_command_orb *orb =
1338 		container_of(base_orb, struct sbp2_command_orb, base);
1339 	struct fw_device *device = target_parent_device(base_orb->lu->tgt);
1340 	int result;
1341 
1342 	if (status != NULL) {
1343 		if (STATUS_GET_DEAD(*status))
1344 			sbp2_agent_reset_no_wait(base_orb->lu);
1345 
1346 		switch (STATUS_GET_RESPONSE(*status)) {
1347 		case SBP2_STATUS_REQUEST_COMPLETE:
1348 			result = DID_OK << 16;
1349 			break;
1350 		case SBP2_STATUS_TRANSPORT_FAILURE:
1351 			result = DID_BUS_BUSY << 16;
1352 			break;
1353 		case SBP2_STATUS_ILLEGAL_REQUEST:
1354 		case SBP2_STATUS_VENDOR_DEPENDENT:
1355 		default:
1356 			result = DID_ERROR << 16;
1357 			break;
1358 		}
1359 
1360 		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1361 			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1362 							   orb->cmd->sense_buffer);
1363 	} else {
1364 		/*
1365 		 * If the orb completes with status == NULL, something
1366 		 * went wrong, typically a bus reset happened mid-orb
1367 		 * or when sending the write (less likely).
1368 		 */
1369 		result = DID_BUS_BUSY << 16;
1370 		sbp2_conditionally_block(base_orb->lu);
1371 	}
1372 
1373 	dma_unmap_single(device->card->device, orb->base.request_bus,
1374 			 sizeof(orb->request), DMA_TO_DEVICE);
1375 	sbp2_unmap_scatterlist(device->card->device, orb);
1376 
1377 	orb->cmd->result = result;
1378 	orb->cmd->scsi_done(orb->cmd);
1379 }
1380 
1381 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1382 		struct fw_device *device, struct sbp2_logical_unit *lu)
1383 {
1384 	struct scatterlist *sg = scsi_sglist(orb->cmd);
1385 	int i, n;
1386 
1387 	n = scsi_dma_map(orb->cmd);
1388 	if (n <= 0)
1389 		goto fail;
1390 
1391 	/*
1392 	 * Handle the special case where there is only one element in
1393 	 * the scatter list by converting it to an immediate block
1394 	 * request. This is also a workaround for broken devices such
1395 	 * as the second generation iPod which doesn't support page
1396 	 * tables.
1397 	 */
1398 	if (n == 1) {
1399 		orb->request.data_descriptor.high =
1400 			cpu_to_be32(lu->tgt->address_high);
1401 		orb->request.data_descriptor.low  =
1402 			cpu_to_be32(sg_dma_address(sg));
1403 		orb->request.misc |=
1404 			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1405 		return 0;
1406 	}
1407 
1408 	for_each_sg(sg, sg, n, i) {
1409 		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1410 		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1411 	}
1412 
1413 	orb->page_table_bus =
1414 		dma_map_single(device->card->device, orb->page_table,
1415 			       sizeof(orb->page_table), DMA_TO_DEVICE);
1416 	if (dma_mapping_error(device->card->device, orb->page_table_bus))
1417 		goto fail_page_table;
1418 
1419 	/*
1420 	 * The data_descriptor pointer is the one case where we need
1421 	 * to fill in the node ID part of the address.  All other
1422 	 * pointers assume that the data referenced reside on the
1423 	 * initiator (i.e. us), but data_descriptor can refer to data
1424 	 * on other nodes so we need to put our ID in descriptor.high.
1425 	 */
1426 	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1427 	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1428 	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1429 					 COMMAND_ORB_DATA_SIZE(n));
1430 
1431 	return 0;
1432 
1433  fail_page_table:
1434 	scsi_dma_unmap(orb->cmd);
1435  fail:
1436 	return -ENOMEM;
1437 }
1438 
1439 /* SCSI stack integration */
1440 
1441 static int sbp2_scsi_queuecommand(struct Scsi_Host *shost,
1442 				  struct scsi_cmnd *cmd)
1443 {
1444 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1445 	struct fw_device *device = target_parent_device(lu->tgt);
1446 	struct sbp2_command_orb *orb;
1447 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1448 
1449 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1450 	if (orb == NULL)
1451 		return SCSI_MLQUEUE_HOST_BUSY;
1452 
1453 	/* Initialize rcode to something not RCODE_COMPLETE. */
1454 	orb->base.rcode = -1;
1455 	kref_init(&orb->base.kref);
1456 	orb->cmd = cmd;
1457 	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1458 	orb->request.misc = cpu_to_be32(
1459 		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1460 		COMMAND_ORB_SPEED(device->max_speed) |
1461 		COMMAND_ORB_NOTIFY);
1462 
1463 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1464 		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1465 
1466 	generation = device->generation;
1467 	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1468 
1469 	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1470 		goto out;
1471 
1472 	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1473 
1474 	orb->base.callback = complete_command_orb;
1475 	orb->base.request_bus =
1476 		dma_map_single(device->card->device, &orb->request,
1477 			       sizeof(orb->request), DMA_TO_DEVICE);
1478 	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1479 		sbp2_unmap_scatterlist(device->card->device, orb);
1480 		goto out;
1481 	}
1482 
1483 	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1484 		      lu->command_block_agent_address + SBP2_ORB_POINTER);
1485 	retval = 0;
1486  out:
1487 	kref_put(&orb->base.kref, free_orb);
1488 	return retval;
1489 }
1490 
1491 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1492 {
1493 	struct sbp2_logical_unit *lu = sdev->hostdata;
1494 
1495 	/* (Re-)Adding logical units via the SCSI stack is not supported. */
1496 	if (!lu)
1497 		return -ENOSYS;
1498 
1499 	sdev->allow_restart = 1;
1500 
1501 	/*
1502 	 * SBP-2 does not require any alignment, but we set it anyway
1503 	 * for compatibility with earlier versions of this driver.
1504 	 */
1505 	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1506 
1507 	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1508 		sdev->inquiry_len = 36;
1509 
1510 	return 0;
1511 }
1512 
1513 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1514 {
1515 	struct sbp2_logical_unit *lu = sdev->hostdata;
1516 
1517 	sdev->use_10_for_rw = 1;
1518 
1519 	if (sbp2_param_exclusive_login)
1520 		sdev->manage_start_stop = 1;
1521 
1522 	if (sdev->type == TYPE_ROM)
1523 		sdev->use_10_for_ms = 1;
1524 
1525 	if (sdev->type == TYPE_DISK &&
1526 	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1527 		sdev->skip_ms_page_8 = 1;
1528 
1529 	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1530 		sdev->fix_capacity = 1;
1531 
1532 	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1533 		sdev->start_stop_pwr_cond = 1;
1534 
1535 	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1536 		blk_queue_max_hw_sectors(sdev->request_queue, 128 * 1024 / 512);
1537 
1538 	return 0;
1539 }
1540 
1541 /*
1542  * Called by scsi stack when something has really gone wrong.  Usually
1543  * called when a command has timed-out for some reason.
1544  */
1545 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1546 {
1547 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1548 
1549 	dev_notice(lu_dev(lu), "sbp2_scsi_abort\n");
1550 	sbp2_agent_reset(lu);
1551 	sbp2_cancel_orbs(lu);
1552 
1553 	return SUCCESS;
1554 }
1555 
1556 /*
1557  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1558  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1559  *
1560  * This is the concatenation of target port identifier and logical unit
1561  * identifier as per SAM-2...SAM-4 annex A.
1562  */
1563 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1564 			struct device_attribute *attr, char *buf)
1565 {
1566 	struct scsi_device *sdev = to_scsi_device(dev);
1567 	struct sbp2_logical_unit *lu;
1568 
1569 	if (!sdev)
1570 		return 0;
1571 
1572 	lu = sdev->hostdata;
1573 
1574 	return sprintf(buf, "%016llx:%06x:%04x\n",
1575 			(unsigned long long)lu->tgt->guid,
1576 			lu->tgt->directory_id, lu->lun);
1577 }
1578 
1579 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1580 
1581 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1582 	&dev_attr_ieee1394_id,
1583 	NULL
1584 };
1585 
1586 static struct scsi_host_template scsi_driver_template = {
1587 	.module			= THIS_MODULE,
1588 	.name			= "SBP-2 IEEE-1394",
1589 	.proc_name		= "sbp2",
1590 	.queuecommand		= sbp2_scsi_queuecommand,
1591 	.slave_alloc		= sbp2_scsi_slave_alloc,
1592 	.slave_configure	= sbp2_scsi_slave_configure,
1593 	.eh_abort_handler	= sbp2_scsi_abort,
1594 	.this_id		= -1,
1595 	.sg_tablesize		= SG_ALL,
1596 	.max_segment_size	= SBP2_MAX_SEG_SIZE,
1597 	.can_queue		= 1,
1598 	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
1599 };
1600 
1601 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1602 MODULE_DESCRIPTION("SCSI over IEEE1394");
1603 MODULE_LICENSE("GPL");
1604 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1605 
1606 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1607 MODULE_ALIAS("sbp2");
1608 
1609 static int __init sbp2_init(void)
1610 {
1611 	return driver_register(&sbp2_driver.driver);
1612 }
1613 
1614 static void __exit sbp2_cleanup(void)
1615 {
1616 	driver_unregister(&sbp2_driver.driver);
1617 }
1618 
1619 module_init(sbp2_init);
1620 module_exit(sbp2_cleanup);
1621