xref: /openbmc/linux/drivers/firewire/sbp2.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  * SBP2 driver (SCSI over IEEE1394)
3  *
4  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 /*
22  * The basic structure of this driver is based on the old storage driver,
23  * drivers/ieee1394/sbp2.c, originally written by
24  *     James Goodwin <jamesg@filanet.com>
25  * with later contributions and ongoing maintenance from
26  *     Ben Collins <bcollins@debian.org>,
27  *     Stefan Richter <stefanr@s5r6.in-berlin.de>
28  * and many others.
29  */
30 
31 #include <linux/blkdev.h>
32 #include <linux/bug.h>
33 #include <linux/completion.h>
34 #include <linux/delay.h>
35 #include <linux/device.h>
36 #include <linux/dma-mapping.h>
37 #include <linux/firewire.h>
38 #include <linux/firewire-constants.h>
39 #include <linux/init.h>
40 #include <linux/jiffies.h>
41 #include <linux/kernel.h>
42 #include <linux/kref.h>
43 #include <linux/list.h>
44 #include <linux/mod_devicetable.h>
45 #include <linux/module.h>
46 #include <linux/moduleparam.h>
47 #include <linux/scatterlist.h>
48 #include <linux/slab.h>
49 #include <linux/spinlock.h>
50 #include <linux/string.h>
51 #include <linux/stringify.h>
52 #include <linux/workqueue.h>
53 
54 #include <asm/byteorder.h>
55 #include <asm/system.h>
56 
57 #include <scsi/scsi.h>
58 #include <scsi/scsi_cmnd.h>
59 #include <scsi/scsi_device.h>
60 #include <scsi/scsi_host.h>
61 
62 /*
63  * So far only bridges from Oxford Semiconductor are known to support
64  * concurrent logins. Depending on firmware, four or two concurrent logins
65  * are possible on OXFW911 and newer Oxsemi bridges.
66  *
67  * Concurrent logins are useful together with cluster filesystems.
68  */
69 static int sbp2_param_exclusive_login = 1;
70 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
71 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
72 		 "(default = Y, use N for concurrent initiators)");
73 
74 /*
75  * Flags for firmware oddities
76  *
77  * - 128kB max transfer
78  *   Limit transfer size. Necessary for some old bridges.
79  *
80  * - 36 byte inquiry
81  *   When scsi_mod probes the device, let the inquiry command look like that
82  *   from MS Windows.
83  *
84  * - skip mode page 8
85  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
86  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
87  *
88  * - fix capacity
89  *   Tell sd_mod to correct the last sector number reported by read_capacity.
90  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
91  *   Don't use this with devices which don't have this bug.
92  *
93  * - delay inquiry
94  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
95  *
96  * - power condition
97  *   Set the power condition field in the START STOP UNIT commands sent by
98  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
99  *   Some disks need this to spin down or to resume properly.
100  *
101  * - override internal blacklist
102  *   Instead of adding to the built-in blacklist, use only the workarounds
103  *   specified in the module load parameter.
104  *   Useful if a blacklist entry interfered with a non-broken device.
105  */
106 #define SBP2_WORKAROUND_128K_MAX_TRANS	0x1
107 #define SBP2_WORKAROUND_INQUIRY_36	0x2
108 #define SBP2_WORKAROUND_MODE_SENSE_8	0x4
109 #define SBP2_WORKAROUND_FIX_CAPACITY	0x8
110 #define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
111 #define SBP2_INQUIRY_DELAY		12
112 #define SBP2_WORKAROUND_POWER_CONDITION	0x20
113 #define SBP2_WORKAROUND_OVERRIDE	0x100
114 
115 static int sbp2_param_workarounds;
116 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
117 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
118 	", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
119 	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
120 	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
121 	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
122 	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
123 	", set power condition in start stop unit = "
124 				  __stringify(SBP2_WORKAROUND_POWER_CONDITION)
125 	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
126 	", or a combination)");
127 
128 /* I don't know why the SCSI stack doesn't define something like this... */
129 typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
130 
131 static const char sbp2_driver_name[] = "sbp2";
132 
133 /*
134  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
135  * and one struct scsi_device per sbp2_logical_unit.
136  */
137 struct sbp2_logical_unit {
138 	struct sbp2_target *tgt;
139 	struct list_head link;
140 	struct fw_address_handler address_handler;
141 	struct list_head orb_list;
142 
143 	u64 command_block_agent_address;
144 	u16 lun;
145 	int login_id;
146 
147 	/*
148 	 * The generation is updated once we've logged in or reconnected
149 	 * to the logical unit.  Thus, I/O to the device will automatically
150 	 * fail and get retried if it happens in a window where the device
151 	 * is not ready, e.g. after a bus reset but before we reconnect.
152 	 */
153 	int generation;
154 	int retries;
155 	struct delayed_work work;
156 	bool has_sdev;
157 	bool blocked;
158 };
159 
160 /*
161  * We create one struct sbp2_target per IEEE 1212 Unit Directory
162  * and one struct Scsi_Host per sbp2_target.
163  */
164 struct sbp2_target {
165 	struct kref kref;
166 	struct fw_unit *unit;
167 	const char *bus_id;
168 	struct list_head lu_list;
169 
170 	u64 management_agent_address;
171 	u64 guid;
172 	int directory_id;
173 	int node_id;
174 	int address_high;
175 	unsigned int workarounds;
176 	unsigned int mgt_orb_timeout;
177 	unsigned int max_payload;
178 
179 	int dont_block;	/* counter for each logical unit */
180 	int blocked;	/* ditto */
181 };
182 
183 static struct fw_device *target_device(struct sbp2_target *tgt)
184 {
185 	return fw_parent_device(tgt->unit);
186 }
187 
188 /* Impossible login_id, to detect logout attempt before successful login */
189 #define INVALID_LOGIN_ID 0x10000
190 
191 #define SBP2_ORB_TIMEOUT		2000U		/* Timeout in ms */
192 #define SBP2_ORB_NULL			0x80000000
193 #define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
194 #define SBP2_CYCLE_LIMIT		(0xc8 << 12)	/* 200 125us cycles */
195 
196 /*
197  * There is no transport protocol limit to the CDB length,  but we implement
198  * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
199  */
200 #define SBP2_MAX_CDB_SIZE		16
201 
202 /*
203  * The default maximum s/g segment size of a FireWire controller is
204  * usually 0x10000, but SBP-2 only allows 0xffff. Since buffers have to
205  * be quadlet-aligned, we set the length limit to 0xffff & ~3.
206  */
207 #define SBP2_MAX_SEG_SIZE		0xfffc
208 
209 /* Unit directory keys */
210 #define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
211 #define SBP2_CSR_FIRMWARE_REVISION	0x3c
212 #define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
213 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4
214 
215 /* Management orb opcodes */
216 #define SBP2_LOGIN_REQUEST		0x0
217 #define SBP2_QUERY_LOGINS_REQUEST	0x1
218 #define SBP2_RECONNECT_REQUEST		0x3
219 #define SBP2_SET_PASSWORD_REQUEST	0x4
220 #define SBP2_LOGOUT_REQUEST		0x7
221 #define SBP2_ABORT_TASK_REQUEST		0xb
222 #define SBP2_ABORT_TASK_SET		0xc
223 #define SBP2_LOGICAL_UNIT_RESET		0xe
224 #define SBP2_TARGET_RESET_REQUEST	0xf
225 
226 /* Offsets for command block agent registers */
227 #define SBP2_AGENT_STATE		0x00
228 #define SBP2_AGENT_RESET		0x04
229 #define SBP2_ORB_POINTER		0x08
230 #define SBP2_DOORBELL			0x10
231 #define SBP2_UNSOLICITED_STATUS_ENABLE	0x14
232 
233 /* Status write response codes */
234 #define SBP2_STATUS_REQUEST_COMPLETE	0x0
235 #define SBP2_STATUS_TRANSPORT_FAILURE	0x1
236 #define SBP2_STATUS_ILLEGAL_REQUEST	0x2
237 #define SBP2_STATUS_VENDOR_DEPENDENT	0x3
238 
239 #define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
240 #define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
241 #define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
242 #define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
243 #define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
244 #define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
245 #define STATUS_GET_ORB_LOW(v)		((v).orb_low)
246 #define STATUS_GET_DATA(v)		((v).data)
247 
248 struct sbp2_status {
249 	u32 status;
250 	u32 orb_low;
251 	u8 data[24];
252 };
253 
254 struct sbp2_pointer {
255 	__be32 high;
256 	__be32 low;
257 };
258 
259 struct sbp2_orb {
260 	struct fw_transaction t;
261 	struct kref kref;
262 	dma_addr_t request_bus;
263 	int rcode;
264 	struct sbp2_pointer pointer;
265 	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
266 	struct list_head link;
267 };
268 
269 #define MANAGEMENT_ORB_LUN(v)			((v))
270 #define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
271 #define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
272 #define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
273 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
274 #define MANAGEMENT_ORB_NOTIFY			((1) << 31)
275 
276 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
277 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
278 
279 struct sbp2_management_orb {
280 	struct sbp2_orb base;
281 	struct {
282 		struct sbp2_pointer password;
283 		struct sbp2_pointer response;
284 		__be32 misc;
285 		__be32 length;
286 		struct sbp2_pointer status_fifo;
287 	} request;
288 	__be32 response[4];
289 	dma_addr_t response_bus;
290 	struct completion done;
291 	struct sbp2_status status;
292 };
293 
294 struct sbp2_login_response {
295 	__be32 misc;
296 	struct sbp2_pointer command_block_agent;
297 	__be32 reconnect_hold;
298 };
299 #define COMMAND_ORB_DATA_SIZE(v)	((v))
300 #define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
301 #define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
302 #define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
303 #define COMMAND_ORB_SPEED(v)		((v) << 24)
304 #define COMMAND_ORB_DIRECTION		((1) << 27)
305 #define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
306 #define COMMAND_ORB_NOTIFY		((1) << 31)
307 
308 struct sbp2_command_orb {
309 	struct sbp2_orb base;
310 	struct {
311 		struct sbp2_pointer next;
312 		struct sbp2_pointer data_descriptor;
313 		__be32 misc;
314 		u8 command_block[SBP2_MAX_CDB_SIZE];
315 	} request;
316 	struct scsi_cmnd *cmd;
317 	scsi_done_fn_t done;
318 	struct sbp2_logical_unit *lu;
319 
320 	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
321 	dma_addr_t page_table_bus;
322 };
323 
324 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
325 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
326 
327 /*
328  * List of devices with known bugs.
329  *
330  * The firmware_revision field, masked with 0xffff00, is the best
331  * indicator for the type of bridge chip of a device.  It yields a few
332  * false positives but this did not break correctly behaving devices
333  * so far.
334  */
335 static const struct {
336 	u32 firmware_revision;
337 	u32 model;
338 	unsigned int workarounds;
339 } sbp2_workarounds_table[] = {
340 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
341 		.firmware_revision	= 0x002800,
342 		.model			= 0x001010,
343 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
344 					  SBP2_WORKAROUND_MODE_SENSE_8 |
345 					  SBP2_WORKAROUND_POWER_CONDITION,
346 	},
347 	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
348 		.firmware_revision	= 0x002800,
349 		.model			= 0x000000,
350 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
351 	},
352 	/* Initio bridges, actually only needed for some older ones */ {
353 		.firmware_revision	= 0x000200,
354 		.model			= SBP2_ROM_VALUE_WILDCARD,
355 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
356 	},
357 	/* PL-3507 bridge with Prolific firmware */ {
358 		.firmware_revision	= 0x012800,
359 		.model			= SBP2_ROM_VALUE_WILDCARD,
360 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
361 	},
362 	/* Symbios bridge */ {
363 		.firmware_revision	= 0xa0b800,
364 		.model			= SBP2_ROM_VALUE_WILDCARD,
365 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
366 	},
367 	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
368 		.firmware_revision	= 0x002600,
369 		.model			= SBP2_ROM_VALUE_WILDCARD,
370 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
371 	},
372 	/*
373 	 * iPod 2nd generation: needs 128k max transfer size workaround
374 	 * iPod 3rd generation: needs fix capacity workaround
375 	 */
376 	{
377 		.firmware_revision	= 0x0a2700,
378 		.model			= 0x000000,
379 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
380 					  SBP2_WORKAROUND_FIX_CAPACITY,
381 	},
382 	/* iPod 4th generation */ {
383 		.firmware_revision	= 0x0a2700,
384 		.model			= 0x000021,
385 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
386 	},
387 	/* iPod mini */ {
388 		.firmware_revision	= 0x0a2700,
389 		.model			= 0x000022,
390 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
391 	},
392 	/* iPod mini */ {
393 		.firmware_revision	= 0x0a2700,
394 		.model			= 0x000023,
395 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
396 	},
397 	/* iPod Photo */ {
398 		.firmware_revision	= 0x0a2700,
399 		.model			= 0x00007e,
400 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
401 	}
402 };
403 
404 static void free_orb(struct kref *kref)
405 {
406 	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
407 
408 	kfree(orb);
409 }
410 
411 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
412 			      int tcode, int destination, int source,
413 			      int generation, unsigned long long offset,
414 			      void *payload, size_t length, void *callback_data)
415 {
416 	struct sbp2_logical_unit *lu = callback_data;
417 	struct sbp2_orb *orb;
418 	struct sbp2_status status;
419 	unsigned long flags;
420 
421 	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
422 	    length < 8 || length > sizeof(status)) {
423 		fw_send_response(card, request, RCODE_TYPE_ERROR);
424 		return;
425 	}
426 
427 	status.status  = be32_to_cpup(payload);
428 	status.orb_low = be32_to_cpup(payload + 4);
429 	memset(status.data, 0, sizeof(status.data));
430 	if (length > 8)
431 		memcpy(status.data, payload + 8, length - 8);
432 
433 	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
434 		fw_notify("non-orb related status write, not handled\n");
435 		fw_send_response(card, request, RCODE_COMPLETE);
436 		return;
437 	}
438 
439 	/* Lookup the orb corresponding to this status write. */
440 	spin_lock_irqsave(&card->lock, flags);
441 	list_for_each_entry(orb, &lu->orb_list, link) {
442 		if (STATUS_GET_ORB_HIGH(status) == 0 &&
443 		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
444 			orb->rcode = RCODE_COMPLETE;
445 			list_del(&orb->link);
446 			break;
447 		}
448 	}
449 	spin_unlock_irqrestore(&card->lock, flags);
450 
451 	if (&orb->link != &lu->orb_list) {
452 		orb->callback(orb, &status);
453 		kref_put(&orb->kref, free_orb); /* orb callback reference */
454 	} else {
455 		fw_error("status write for unknown orb\n");
456 	}
457 
458 	fw_send_response(card, request, RCODE_COMPLETE);
459 }
460 
461 static void complete_transaction(struct fw_card *card, int rcode,
462 				 void *payload, size_t length, void *data)
463 {
464 	struct sbp2_orb *orb = data;
465 	unsigned long flags;
466 
467 	/*
468 	 * This is a little tricky.  We can get the status write for
469 	 * the orb before we get this callback.  The status write
470 	 * handler above will assume the orb pointer transaction was
471 	 * successful and set the rcode to RCODE_COMPLETE for the orb.
472 	 * So this callback only sets the rcode if it hasn't already
473 	 * been set and only does the cleanup if the transaction
474 	 * failed and we didn't already get a status write.
475 	 *
476 	 * Here we treat RCODE_CANCELLED like RCODE_COMPLETE because some
477 	 * OXUF936QSE firmwares occasionally respond after Split_Timeout and
478 	 * complete the ORB just fine.  Note, we also get RCODE_CANCELLED
479 	 * from sbp2_cancel_orbs() if fw_cancel_transaction() == 0.
480 	 */
481 	spin_lock_irqsave(&card->lock, flags);
482 
483 	if (orb->rcode == -1)
484 		orb->rcode = rcode;
485 
486 	if (orb->rcode != RCODE_COMPLETE && orb->rcode != RCODE_CANCELLED) {
487 		list_del(&orb->link);
488 		spin_unlock_irqrestore(&card->lock, flags);
489 
490 		orb->callback(orb, NULL);
491 		kref_put(&orb->kref, free_orb); /* orb callback reference */
492 	} else {
493 		spin_unlock_irqrestore(&card->lock, flags);
494 	}
495 
496 	kref_put(&orb->kref, free_orb); /* transaction callback reference */
497 }
498 
499 static void sbp2_send_orb(struct sbp2_orb *orb, struct sbp2_logical_unit *lu,
500 			  int node_id, int generation, u64 offset)
501 {
502 	struct fw_device *device = target_device(lu->tgt);
503 	unsigned long flags;
504 
505 	orb->pointer.high = 0;
506 	orb->pointer.low = cpu_to_be32(orb->request_bus);
507 
508 	spin_lock_irqsave(&device->card->lock, flags);
509 	list_add_tail(&orb->link, &lu->orb_list);
510 	spin_unlock_irqrestore(&device->card->lock, flags);
511 
512 	kref_get(&orb->kref); /* transaction callback reference */
513 	kref_get(&orb->kref); /* orb callback reference */
514 
515 	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
516 			node_id, generation, device->max_speed, offset,
517 			&orb->pointer, 8, complete_transaction, orb);
518 }
519 
520 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
521 {
522 	struct fw_device *device = target_device(lu->tgt);
523 	struct sbp2_orb *orb, *next;
524 	struct list_head list;
525 	unsigned long flags;
526 	int retval = -ENOENT;
527 
528 	INIT_LIST_HEAD(&list);
529 	spin_lock_irqsave(&device->card->lock, flags);
530 	list_splice_init(&lu->orb_list, &list);
531 	spin_unlock_irqrestore(&device->card->lock, flags);
532 
533 	list_for_each_entry_safe(orb, next, &list, link) {
534 		retval = 0;
535 		fw_cancel_transaction(device->card, &orb->t);
536 
537 		orb->rcode = RCODE_CANCELLED;
538 		orb->callback(orb, NULL);
539 		kref_put(&orb->kref, free_orb); /* orb callback reference */
540 	}
541 
542 	return retval;
543 }
544 
545 static void complete_management_orb(struct sbp2_orb *base_orb,
546 				    struct sbp2_status *status)
547 {
548 	struct sbp2_management_orb *orb =
549 		container_of(base_orb, struct sbp2_management_orb, base);
550 
551 	if (status)
552 		memcpy(&orb->status, status, sizeof(*status));
553 	complete(&orb->done);
554 }
555 
556 static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
557 				    int generation, int function,
558 				    int lun_or_login_id, void *response)
559 {
560 	struct fw_device *device = target_device(lu->tgt);
561 	struct sbp2_management_orb *orb;
562 	unsigned int timeout;
563 	int retval = -ENOMEM;
564 
565 	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
566 		return 0;
567 
568 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
569 	if (orb == NULL)
570 		return -ENOMEM;
571 
572 	kref_init(&orb->base.kref);
573 	orb->response_bus =
574 		dma_map_single(device->card->device, &orb->response,
575 			       sizeof(orb->response), DMA_FROM_DEVICE);
576 	if (dma_mapping_error(device->card->device, orb->response_bus))
577 		goto fail_mapping_response;
578 
579 	orb->request.response.high = 0;
580 	orb->request.response.low  = cpu_to_be32(orb->response_bus);
581 
582 	orb->request.misc = cpu_to_be32(
583 		MANAGEMENT_ORB_NOTIFY |
584 		MANAGEMENT_ORB_FUNCTION(function) |
585 		MANAGEMENT_ORB_LUN(lun_or_login_id));
586 	orb->request.length = cpu_to_be32(
587 		MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
588 
589 	orb->request.status_fifo.high =
590 		cpu_to_be32(lu->address_handler.offset >> 32);
591 	orb->request.status_fifo.low  =
592 		cpu_to_be32(lu->address_handler.offset);
593 
594 	if (function == SBP2_LOGIN_REQUEST) {
595 		/* Ask for 2^2 == 4 seconds reconnect grace period */
596 		orb->request.misc |= cpu_to_be32(
597 			MANAGEMENT_ORB_RECONNECT(2) |
598 			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
599 		timeout = lu->tgt->mgt_orb_timeout;
600 	} else {
601 		timeout = SBP2_ORB_TIMEOUT;
602 	}
603 
604 	init_completion(&orb->done);
605 	orb->base.callback = complete_management_orb;
606 
607 	orb->base.request_bus =
608 		dma_map_single(device->card->device, &orb->request,
609 			       sizeof(orb->request), DMA_TO_DEVICE);
610 	if (dma_mapping_error(device->card->device, orb->base.request_bus))
611 		goto fail_mapping_request;
612 
613 	sbp2_send_orb(&orb->base, lu, node_id, generation,
614 		      lu->tgt->management_agent_address);
615 
616 	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
617 
618 	retval = -EIO;
619 	if (sbp2_cancel_orbs(lu) == 0) {
620 		fw_error("%s: orb reply timed out, rcode=0x%02x\n",
621 			 lu->tgt->bus_id, orb->base.rcode);
622 		goto out;
623 	}
624 
625 	if (orb->base.rcode != RCODE_COMPLETE) {
626 		fw_error("%s: management write failed, rcode 0x%02x\n",
627 			 lu->tgt->bus_id, orb->base.rcode);
628 		goto out;
629 	}
630 
631 	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
632 	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
633 		fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
634 			 STATUS_GET_RESPONSE(orb->status),
635 			 STATUS_GET_SBP_STATUS(orb->status));
636 		goto out;
637 	}
638 
639 	retval = 0;
640  out:
641 	dma_unmap_single(device->card->device, orb->base.request_bus,
642 			 sizeof(orb->request), DMA_TO_DEVICE);
643  fail_mapping_request:
644 	dma_unmap_single(device->card->device, orb->response_bus,
645 			 sizeof(orb->response), DMA_FROM_DEVICE);
646  fail_mapping_response:
647 	if (response)
648 		memcpy(response, orb->response, sizeof(orb->response));
649 	kref_put(&orb->base.kref, free_orb);
650 
651 	return retval;
652 }
653 
654 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
655 {
656 	struct fw_device *device = target_device(lu->tgt);
657 	__be32 d = 0;
658 
659 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
660 			   lu->tgt->node_id, lu->generation, device->max_speed,
661 			   lu->command_block_agent_address + SBP2_AGENT_RESET,
662 			   &d, 4);
663 }
664 
665 static void complete_agent_reset_write_no_wait(struct fw_card *card,
666 		int rcode, void *payload, size_t length, void *data)
667 {
668 	kfree(data);
669 }
670 
671 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
672 {
673 	struct fw_device *device = target_device(lu->tgt);
674 	struct fw_transaction *t;
675 	static __be32 d;
676 
677 	t = kmalloc(sizeof(*t), GFP_ATOMIC);
678 	if (t == NULL)
679 		return;
680 
681 	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
682 			lu->tgt->node_id, lu->generation, device->max_speed,
683 			lu->command_block_agent_address + SBP2_AGENT_RESET,
684 			&d, 4, complete_agent_reset_write_no_wait, t);
685 }
686 
687 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
688 {
689 	/*
690 	 * We may access dont_block without taking card->lock here:
691 	 * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
692 	 * are currently serialized against each other.
693 	 * And a wrong result in sbp2_conditionally_block()'s access of
694 	 * dont_block is rather harmless, it simply misses its first chance.
695 	 */
696 	--lu->tgt->dont_block;
697 }
698 
699 /*
700  * Blocks lu->tgt if all of the following conditions are met:
701  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
702  *     logical units have been finished (indicated by dont_block == 0).
703  *   - lu->generation is stale.
704  *
705  * Note, scsi_block_requests() must be called while holding card->lock,
706  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
707  * unblock the target.
708  */
709 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
710 {
711 	struct sbp2_target *tgt = lu->tgt;
712 	struct fw_card *card = target_device(tgt)->card;
713 	struct Scsi_Host *shost =
714 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
715 	unsigned long flags;
716 
717 	spin_lock_irqsave(&card->lock, flags);
718 	if (!tgt->dont_block && !lu->blocked &&
719 	    lu->generation != card->generation) {
720 		lu->blocked = true;
721 		if (++tgt->blocked == 1)
722 			scsi_block_requests(shost);
723 	}
724 	spin_unlock_irqrestore(&card->lock, flags);
725 }
726 
727 /*
728  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
729  * Note, it is harmless to run scsi_unblock_requests() outside the
730  * card->lock protected section.  On the other hand, running it inside
731  * the section might clash with shost->host_lock.
732  */
733 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
734 {
735 	struct sbp2_target *tgt = lu->tgt;
736 	struct fw_card *card = target_device(tgt)->card;
737 	struct Scsi_Host *shost =
738 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
739 	unsigned long flags;
740 	bool unblock = false;
741 
742 	spin_lock_irqsave(&card->lock, flags);
743 	if (lu->blocked && lu->generation == card->generation) {
744 		lu->blocked = false;
745 		unblock = --tgt->blocked == 0;
746 	}
747 	spin_unlock_irqrestore(&card->lock, flags);
748 
749 	if (unblock)
750 		scsi_unblock_requests(shost);
751 }
752 
753 /*
754  * Prevents future blocking of tgt and unblocks it.
755  * Note, it is harmless to run scsi_unblock_requests() outside the
756  * card->lock protected section.  On the other hand, running it inside
757  * the section might clash with shost->host_lock.
758  */
759 static void sbp2_unblock(struct sbp2_target *tgt)
760 {
761 	struct fw_card *card = target_device(tgt)->card;
762 	struct Scsi_Host *shost =
763 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
764 	unsigned long flags;
765 
766 	spin_lock_irqsave(&card->lock, flags);
767 	++tgt->dont_block;
768 	spin_unlock_irqrestore(&card->lock, flags);
769 
770 	scsi_unblock_requests(shost);
771 }
772 
773 static int sbp2_lun2int(u16 lun)
774 {
775 	struct scsi_lun eight_bytes_lun;
776 
777 	memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
778 	eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
779 	eight_bytes_lun.scsi_lun[1] = lun & 0xff;
780 
781 	return scsilun_to_int(&eight_bytes_lun);
782 }
783 
784 static void sbp2_release_target(struct kref *kref)
785 {
786 	struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
787 	struct sbp2_logical_unit *lu, *next;
788 	struct Scsi_Host *shost =
789 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
790 	struct scsi_device *sdev;
791 	struct fw_device *device = target_device(tgt);
792 
793 	/* prevent deadlocks */
794 	sbp2_unblock(tgt);
795 
796 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
797 		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
798 		if (sdev) {
799 			scsi_remove_device(sdev);
800 			scsi_device_put(sdev);
801 		}
802 		if (lu->login_id != INVALID_LOGIN_ID) {
803 			int generation, node_id;
804 			/*
805 			 * tgt->node_id may be obsolete here if we failed
806 			 * during initial login or after a bus reset where
807 			 * the topology changed.
808 			 */
809 			generation = device->generation;
810 			smp_rmb(); /* node_id vs. generation */
811 			node_id    = device->node_id;
812 			sbp2_send_management_orb(lu, node_id, generation,
813 						 SBP2_LOGOUT_REQUEST,
814 						 lu->login_id, NULL);
815 		}
816 		fw_core_remove_address_handler(&lu->address_handler);
817 		list_del(&lu->link);
818 		kfree(lu);
819 	}
820 	scsi_remove_host(shost);
821 	fw_notify("released %s, target %d:0:0\n", tgt->bus_id, shost->host_no);
822 
823 	fw_unit_put(tgt->unit);
824 	scsi_host_put(shost);
825 	fw_device_put(device);
826 }
827 
828 static void sbp2_target_get(struct sbp2_target *tgt)
829 {
830 	kref_get(&tgt->kref);
831 }
832 
833 static void sbp2_target_put(struct sbp2_target *tgt)
834 {
835 	kref_put(&tgt->kref, sbp2_release_target);
836 }
837 
838 static struct workqueue_struct *sbp2_wq;
839 
840 /*
841  * Always get the target's kref when scheduling work on one its units.
842  * Each workqueue job is responsible to call sbp2_target_put() upon return.
843  */
844 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
845 {
846 	sbp2_target_get(lu->tgt);
847 	if (!queue_delayed_work(sbp2_wq, &lu->work, delay))
848 		sbp2_target_put(lu->tgt);
849 }
850 
851 /*
852  * Write retransmit retry values into the BUSY_TIMEOUT register.
853  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
854  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
855  *   saner value after logging into the device.
856  * - The dual-phase retry protocol is optional to implement, and if not
857  *   supported, writes to the dual-phase portion of the register will be
858  *   ignored. We try to write the original 1394-1995 default here.
859  * - In the case of devices that are also SBP-3-compliant, all writes are
860  *   ignored, as the register is read-only, but contains single-phase retry of
861  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
862  *   write attempt is safe and yields more consistent behavior for all devices.
863  *
864  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
865  * and section 6.4 of the SBP-3 spec for further details.
866  */
867 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
868 {
869 	struct fw_device *device = target_device(lu->tgt);
870 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
871 
872 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
873 			   lu->tgt->node_id, lu->generation, device->max_speed,
874 			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &d, 4);
875 }
876 
877 static void sbp2_reconnect(struct work_struct *work);
878 
879 static void sbp2_login(struct work_struct *work)
880 {
881 	struct sbp2_logical_unit *lu =
882 		container_of(work, struct sbp2_logical_unit, work.work);
883 	struct sbp2_target *tgt = lu->tgt;
884 	struct fw_device *device = target_device(tgt);
885 	struct Scsi_Host *shost;
886 	struct scsi_device *sdev;
887 	struct sbp2_login_response response;
888 	int generation, node_id, local_node_id;
889 
890 	if (fw_device_is_shutdown(device))
891 		goto out;
892 
893 	generation    = device->generation;
894 	smp_rmb();    /* node IDs must not be older than generation */
895 	node_id       = device->node_id;
896 	local_node_id = device->card->node_id;
897 
898 	/* If this is a re-login attempt, log out, or we might be rejected. */
899 	if (lu->has_sdev)
900 		sbp2_send_management_orb(lu, device->node_id, generation,
901 				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
902 
903 	if (sbp2_send_management_orb(lu, node_id, generation,
904 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
905 		if (lu->retries++ < 5) {
906 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
907 		} else {
908 			fw_error("%s: failed to login to LUN %04x\n",
909 				 tgt->bus_id, lu->lun);
910 			/* Let any waiting I/O fail from now on. */
911 			sbp2_unblock(lu->tgt);
912 		}
913 		goto out;
914 	}
915 
916 	tgt->node_id	  = node_id;
917 	tgt->address_high = local_node_id << 16;
918 	smp_wmb();	  /* node IDs must not be older than generation */
919 	lu->generation	  = generation;
920 
921 	lu->command_block_agent_address =
922 		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
923 		      << 32) | be32_to_cpu(response.command_block_agent.low);
924 	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
925 
926 	fw_notify("%s: logged in to LUN %04x (%d retries)\n",
927 		  tgt->bus_id, lu->lun, lu->retries);
928 
929 	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
930 	sbp2_set_busy_timeout(lu);
931 
932 	PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
933 	sbp2_agent_reset(lu);
934 
935 	/* This was a re-login. */
936 	if (lu->has_sdev) {
937 		sbp2_cancel_orbs(lu);
938 		sbp2_conditionally_unblock(lu);
939 		goto out;
940 	}
941 
942 	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
943 		ssleep(SBP2_INQUIRY_DELAY);
944 
945 	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
946 	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
947 	/*
948 	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
949 	 * Therefore __scsi_add_device() will get into trouble if a bus reset
950 	 * happens in parallel.  It will either fail or leave us with an
951 	 * unusable sdev.  As a workaround we check for this and retry the
952 	 * whole login and SCSI probing.
953 	 */
954 
955 	/* Reported error during __scsi_add_device() */
956 	if (IS_ERR(sdev))
957 		goto out_logout_login;
958 
959 	/* Unreported error during __scsi_add_device() */
960 	smp_rmb(); /* get current card generation */
961 	if (generation != device->card->generation) {
962 		scsi_remove_device(sdev);
963 		scsi_device_put(sdev);
964 		goto out_logout_login;
965 	}
966 
967 	/* No error during __scsi_add_device() */
968 	lu->has_sdev = true;
969 	scsi_device_put(sdev);
970 	sbp2_allow_block(lu);
971 	goto out;
972 
973  out_logout_login:
974 	smp_rmb(); /* generation may have changed */
975 	generation = device->generation;
976 	smp_rmb(); /* node_id must not be older than generation */
977 
978 	sbp2_send_management_orb(lu, device->node_id, generation,
979 				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
980 	/*
981 	 * If a bus reset happened, sbp2_update will have requeued
982 	 * lu->work already.  Reset the work from reconnect to login.
983 	 */
984 	PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
985  out:
986 	sbp2_target_put(tgt);
987 }
988 
989 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
990 {
991 	struct sbp2_logical_unit *lu;
992 
993 	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
994 	if (!lu)
995 		return -ENOMEM;
996 
997 	lu->address_handler.length           = 0x100;
998 	lu->address_handler.address_callback = sbp2_status_write;
999 	lu->address_handler.callback_data    = lu;
1000 
1001 	if (fw_core_add_address_handler(&lu->address_handler,
1002 					&fw_high_memory_region) < 0) {
1003 		kfree(lu);
1004 		return -ENOMEM;
1005 	}
1006 
1007 	lu->tgt      = tgt;
1008 	lu->lun      = lun_entry & 0xffff;
1009 	lu->login_id = INVALID_LOGIN_ID;
1010 	lu->retries  = 0;
1011 	lu->has_sdev = false;
1012 	lu->blocked  = false;
1013 	++tgt->dont_block;
1014 	INIT_LIST_HEAD(&lu->orb_list);
1015 	INIT_DELAYED_WORK(&lu->work, sbp2_login);
1016 
1017 	list_add_tail(&lu->link, &tgt->lu_list);
1018 	return 0;
1019 }
1020 
1021 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
1022 				      const u32 *directory)
1023 {
1024 	struct fw_csr_iterator ci;
1025 	int key, value;
1026 
1027 	fw_csr_iterator_init(&ci, directory);
1028 	while (fw_csr_iterator_next(&ci, &key, &value))
1029 		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1030 		    sbp2_add_logical_unit(tgt, value) < 0)
1031 			return -ENOMEM;
1032 	return 0;
1033 }
1034 
1035 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
1036 			      u32 *model, u32 *firmware_revision)
1037 {
1038 	struct fw_csr_iterator ci;
1039 	int key, value;
1040 
1041 	fw_csr_iterator_init(&ci, directory);
1042 	while (fw_csr_iterator_next(&ci, &key, &value)) {
1043 		switch (key) {
1044 
1045 		case CSR_DEPENDENT_INFO | CSR_OFFSET:
1046 			tgt->management_agent_address =
1047 					CSR_REGISTER_BASE + 4 * value;
1048 			break;
1049 
1050 		case CSR_DIRECTORY_ID:
1051 			tgt->directory_id = value;
1052 			break;
1053 
1054 		case CSR_MODEL:
1055 			*model = value;
1056 			break;
1057 
1058 		case SBP2_CSR_FIRMWARE_REVISION:
1059 			*firmware_revision = value;
1060 			break;
1061 
1062 		case SBP2_CSR_UNIT_CHARACTERISTICS:
1063 			/* the timeout value is stored in 500ms units */
1064 			tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
1065 			break;
1066 
1067 		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1068 			if (sbp2_add_logical_unit(tgt, value) < 0)
1069 				return -ENOMEM;
1070 			break;
1071 
1072 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1073 			/* Adjust for the increment in the iterator */
1074 			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1075 				return -ENOMEM;
1076 			break;
1077 		}
1078 	}
1079 	return 0;
1080 }
1081 
1082 /*
1083  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
1084  * provided in the config rom. Most devices do provide a value, which
1085  * we'll use for login management orbs, but with some sane limits.
1086  */
1087 static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
1088 {
1089 	unsigned int timeout = tgt->mgt_orb_timeout;
1090 
1091 	if (timeout > 40000)
1092 		fw_notify("%s: %ds mgt_ORB_timeout limited to 40s\n",
1093 			  tgt->bus_id, timeout / 1000);
1094 
1095 	tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
1096 }
1097 
1098 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1099 				  u32 firmware_revision)
1100 {
1101 	int i;
1102 	unsigned int w = sbp2_param_workarounds;
1103 
1104 	if (w)
1105 		fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1106 			  "if you need the workarounds parameter for %s\n",
1107 			  tgt->bus_id);
1108 
1109 	if (w & SBP2_WORKAROUND_OVERRIDE)
1110 		goto out;
1111 
1112 	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1113 
1114 		if (sbp2_workarounds_table[i].firmware_revision !=
1115 		    (firmware_revision & 0xffffff00))
1116 			continue;
1117 
1118 		if (sbp2_workarounds_table[i].model != model &&
1119 		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1120 			continue;
1121 
1122 		w |= sbp2_workarounds_table[i].workarounds;
1123 		break;
1124 	}
1125  out:
1126 	if (w)
1127 		fw_notify("Workarounds for %s: 0x%x "
1128 			  "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1129 			  tgt->bus_id, w, firmware_revision, model);
1130 	tgt->workarounds = w;
1131 }
1132 
1133 static struct scsi_host_template scsi_driver_template;
1134 
1135 static int sbp2_probe(struct device *dev)
1136 {
1137 	struct fw_unit *unit = fw_unit(dev);
1138 	struct fw_device *device = fw_parent_device(unit);
1139 	struct sbp2_target *tgt;
1140 	struct sbp2_logical_unit *lu;
1141 	struct Scsi_Host *shost;
1142 	u32 model, firmware_revision;
1143 
1144 	if (dma_get_max_seg_size(device->card->device) > SBP2_MAX_SEG_SIZE)
1145 		BUG_ON(dma_set_max_seg_size(device->card->device,
1146 					    SBP2_MAX_SEG_SIZE));
1147 
1148 	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1149 	if (shost == NULL)
1150 		return -ENOMEM;
1151 
1152 	tgt = (struct sbp2_target *)shost->hostdata;
1153 	dev_set_drvdata(&unit->device, tgt);
1154 	tgt->unit = unit;
1155 	kref_init(&tgt->kref);
1156 	INIT_LIST_HEAD(&tgt->lu_list);
1157 	tgt->bus_id = dev_name(&unit->device);
1158 	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1159 
1160 	if (fw_device_enable_phys_dma(device) < 0)
1161 		goto fail_shost_put;
1162 
1163 	shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1164 
1165 	if (scsi_add_host(shost, &unit->device) < 0)
1166 		goto fail_shost_put;
1167 
1168 	fw_device_get(device);
1169 	fw_unit_get(unit);
1170 
1171 	/* implicit directory ID */
1172 	tgt->directory_id = ((unit->directory - device->config_rom) * 4
1173 			     + CSR_CONFIG_ROM) & 0xffffff;
1174 
1175 	firmware_revision = SBP2_ROM_VALUE_MISSING;
1176 	model		  = SBP2_ROM_VALUE_MISSING;
1177 
1178 	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1179 			       &firmware_revision) < 0)
1180 		goto fail_tgt_put;
1181 
1182 	sbp2_clamp_management_orb_timeout(tgt);
1183 	sbp2_init_workarounds(tgt, model, firmware_revision);
1184 
1185 	/*
1186 	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1187 	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
1188 	 * specifies the max payload size as 2 ^ (max_payload + 2), so
1189 	 * if we set this to max_speed + 7, we get the right value.
1190 	 */
1191 	tgt->max_payload = min(device->max_speed + 7, 10U);
1192 	tgt->max_payload = min(tgt->max_payload, device->card->max_receive - 1);
1193 
1194 	/* Do the login in a workqueue so we can easily reschedule retries. */
1195 	list_for_each_entry(lu, &tgt->lu_list, link)
1196 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1197 	return 0;
1198 
1199  fail_tgt_put:
1200 	sbp2_target_put(tgt);
1201 	return -ENOMEM;
1202 
1203  fail_shost_put:
1204 	scsi_host_put(shost);
1205 	return -ENOMEM;
1206 }
1207 
1208 static int sbp2_remove(struct device *dev)
1209 {
1210 	struct fw_unit *unit = fw_unit(dev);
1211 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1212 
1213 	sbp2_target_put(tgt);
1214 	return 0;
1215 }
1216 
1217 static void sbp2_reconnect(struct work_struct *work)
1218 {
1219 	struct sbp2_logical_unit *lu =
1220 		container_of(work, struct sbp2_logical_unit, work.work);
1221 	struct sbp2_target *tgt = lu->tgt;
1222 	struct fw_device *device = target_device(tgt);
1223 	int generation, node_id, local_node_id;
1224 
1225 	if (fw_device_is_shutdown(device))
1226 		goto out;
1227 
1228 	generation    = device->generation;
1229 	smp_rmb();    /* node IDs must not be older than generation */
1230 	node_id       = device->node_id;
1231 	local_node_id = device->card->node_id;
1232 
1233 	if (sbp2_send_management_orb(lu, node_id, generation,
1234 				     SBP2_RECONNECT_REQUEST,
1235 				     lu->login_id, NULL) < 0) {
1236 		/*
1237 		 * If reconnect was impossible even though we are in the
1238 		 * current generation, fall back and try to log in again.
1239 		 *
1240 		 * We could check for "Function rejected" status, but
1241 		 * looking at the bus generation as simpler and more general.
1242 		 */
1243 		smp_rmb(); /* get current card generation */
1244 		if (generation == device->card->generation ||
1245 		    lu->retries++ >= 5) {
1246 			fw_error("%s: failed to reconnect\n", tgt->bus_id);
1247 			lu->retries = 0;
1248 			PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1249 		}
1250 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1251 		goto out;
1252 	}
1253 
1254 	tgt->node_id      = node_id;
1255 	tgt->address_high = local_node_id << 16;
1256 	smp_wmb();	  /* node IDs must not be older than generation */
1257 	lu->generation	  = generation;
1258 
1259 	fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1260 		  tgt->bus_id, lu->lun, lu->retries);
1261 
1262 	sbp2_agent_reset(lu);
1263 	sbp2_cancel_orbs(lu);
1264 	sbp2_conditionally_unblock(lu);
1265  out:
1266 	sbp2_target_put(tgt);
1267 }
1268 
1269 static void sbp2_update(struct fw_unit *unit)
1270 {
1271 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1272 	struct sbp2_logical_unit *lu;
1273 
1274 	fw_device_enable_phys_dma(fw_parent_device(unit));
1275 
1276 	/*
1277 	 * Fw-core serializes sbp2_update() against sbp2_remove().
1278 	 * Iteration over tgt->lu_list is therefore safe here.
1279 	 */
1280 	list_for_each_entry(lu, &tgt->lu_list, link) {
1281 		sbp2_conditionally_block(lu);
1282 		lu->retries = 0;
1283 		sbp2_queue_work(lu, 0);
1284 	}
1285 }
1286 
1287 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
1288 #define SBP2_SW_VERSION_ENTRY	0x00010483
1289 
1290 static const struct ieee1394_device_id sbp2_id_table[] = {
1291 	{
1292 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1293 				IEEE1394_MATCH_VERSION,
1294 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1295 		.version      = SBP2_SW_VERSION_ENTRY,
1296 	},
1297 	{ }
1298 };
1299 
1300 static struct fw_driver sbp2_driver = {
1301 	.driver   = {
1302 		.owner  = THIS_MODULE,
1303 		.name   = sbp2_driver_name,
1304 		.bus    = &fw_bus_type,
1305 		.probe  = sbp2_probe,
1306 		.remove = sbp2_remove,
1307 	},
1308 	.update   = sbp2_update,
1309 	.id_table = sbp2_id_table,
1310 };
1311 
1312 static void sbp2_unmap_scatterlist(struct device *card_device,
1313 				   struct sbp2_command_orb *orb)
1314 {
1315 	if (scsi_sg_count(orb->cmd))
1316 		dma_unmap_sg(card_device, scsi_sglist(orb->cmd),
1317 			     scsi_sg_count(orb->cmd),
1318 			     orb->cmd->sc_data_direction);
1319 
1320 	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1321 		dma_unmap_single(card_device, orb->page_table_bus,
1322 				 sizeof(orb->page_table), DMA_TO_DEVICE);
1323 }
1324 
1325 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1326 {
1327 	int sam_status;
1328 
1329 	sense_data[0] = 0x70;
1330 	sense_data[1] = 0x0;
1331 	sense_data[2] = sbp2_status[1];
1332 	sense_data[3] = sbp2_status[4];
1333 	sense_data[4] = sbp2_status[5];
1334 	sense_data[5] = sbp2_status[6];
1335 	sense_data[6] = sbp2_status[7];
1336 	sense_data[7] = 10;
1337 	sense_data[8] = sbp2_status[8];
1338 	sense_data[9] = sbp2_status[9];
1339 	sense_data[10] = sbp2_status[10];
1340 	sense_data[11] = sbp2_status[11];
1341 	sense_data[12] = sbp2_status[2];
1342 	sense_data[13] = sbp2_status[3];
1343 	sense_data[14] = sbp2_status[12];
1344 	sense_data[15] = sbp2_status[13];
1345 
1346 	sam_status = sbp2_status[0] & 0x3f;
1347 
1348 	switch (sam_status) {
1349 	case SAM_STAT_GOOD:
1350 	case SAM_STAT_CHECK_CONDITION:
1351 	case SAM_STAT_CONDITION_MET:
1352 	case SAM_STAT_BUSY:
1353 	case SAM_STAT_RESERVATION_CONFLICT:
1354 	case SAM_STAT_COMMAND_TERMINATED:
1355 		return DID_OK << 16 | sam_status;
1356 
1357 	default:
1358 		return DID_ERROR << 16;
1359 	}
1360 }
1361 
1362 static void complete_command_orb(struct sbp2_orb *base_orb,
1363 				 struct sbp2_status *status)
1364 {
1365 	struct sbp2_command_orb *orb =
1366 		container_of(base_orb, struct sbp2_command_orb, base);
1367 	struct fw_device *device = target_device(orb->lu->tgt);
1368 	int result;
1369 
1370 	if (status != NULL) {
1371 		if (STATUS_GET_DEAD(*status))
1372 			sbp2_agent_reset_no_wait(orb->lu);
1373 
1374 		switch (STATUS_GET_RESPONSE(*status)) {
1375 		case SBP2_STATUS_REQUEST_COMPLETE:
1376 			result = DID_OK << 16;
1377 			break;
1378 		case SBP2_STATUS_TRANSPORT_FAILURE:
1379 			result = DID_BUS_BUSY << 16;
1380 			break;
1381 		case SBP2_STATUS_ILLEGAL_REQUEST:
1382 		case SBP2_STATUS_VENDOR_DEPENDENT:
1383 		default:
1384 			result = DID_ERROR << 16;
1385 			break;
1386 		}
1387 
1388 		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1389 			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1390 							   orb->cmd->sense_buffer);
1391 	} else {
1392 		/*
1393 		 * If the orb completes with status == NULL, something
1394 		 * went wrong, typically a bus reset happened mid-orb
1395 		 * or when sending the write (less likely).
1396 		 */
1397 		result = DID_BUS_BUSY << 16;
1398 		sbp2_conditionally_block(orb->lu);
1399 	}
1400 
1401 	dma_unmap_single(device->card->device, orb->base.request_bus,
1402 			 sizeof(orb->request), DMA_TO_DEVICE);
1403 	sbp2_unmap_scatterlist(device->card->device, orb);
1404 
1405 	orb->cmd->result = result;
1406 	orb->done(orb->cmd);
1407 }
1408 
1409 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1410 		struct fw_device *device, struct sbp2_logical_unit *lu)
1411 {
1412 	struct scatterlist *sg = scsi_sglist(orb->cmd);
1413 	int i, n;
1414 
1415 	n = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1416 		       orb->cmd->sc_data_direction);
1417 	if (n == 0)
1418 		goto fail;
1419 
1420 	/*
1421 	 * Handle the special case where there is only one element in
1422 	 * the scatter list by converting it to an immediate block
1423 	 * request. This is also a workaround for broken devices such
1424 	 * as the second generation iPod which doesn't support page
1425 	 * tables.
1426 	 */
1427 	if (n == 1) {
1428 		orb->request.data_descriptor.high =
1429 			cpu_to_be32(lu->tgt->address_high);
1430 		orb->request.data_descriptor.low  =
1431 			cpu_to_be32(sg_dma_address(sg));
1432 		orb->request.misc |=
1433 			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1434 		return 0;
1435 	}
1436 
1437 	for_each_sg(sg, sg, n, i) {
1438 		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1439 		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1440 	}
1441 
1442 	orb->page_table_bus =
1443 		dma_map_single(device->card->device, orb->page_table,
1444 			       sizeof(orb->page_table), DMA_TO_DEVICE);
1445 	if (dma_mapping_error(device->card->device, orb->page_table_bus))
1446 		goto fail_page_table;
1447 
1448 	/*
1449 	 * The data_descriptor pointer is the one case where we need
1450 	 * to fill in the node ID part of the address.  All other
1451 	 * pointers assume that the data referenced reside on the
1452 	 * initiator (i.e. us), but data_descriptor can refer to data
1453 	 * on other nodes so we need to put our ID in descriptor.high.
1454 	 */
1455 	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1456 	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1457 	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1458 					 COMMAND_ORB_DATA_SIZE(n));
1459 
1460 	return 0;
1461 
1462  fail_page_table:
1463 	dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1464 		     scsi_sg_count(orb->cmd), orb->cmd->sc_data_direction);
1465  fail:
1466 	return -ENOMEM;
1467 }
1468 
1469 /* SCSI stack integration */
1470 
1471 static int sbp2_scsi_queuecommand_lck(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1472 {
1473 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1474 	struct fw_device *device = target_device(lu->tgt);
1475 	struct sbp2_command_orb *orb;
1476 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1477 
1478 	/*
1479 	 * Bidirectional commands are not yet implemented, and unknown
1480 	 * transfer direction not handled.
1481 	 */
1482 	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1483 		fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1484 		cmd->result = DID_ERROR << 16;
1485 		done(cmd);
1486 		return 0;
1487 	}
1488 
1489 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1490 	if (orb == NULL) {
1491 		fw_notify("failed to alloc orb\n");
1492 		return SCSI_MLQUEUE_HOST_BUSY;
1493 	}
1494 
1495 	/* Initialize rcode to something not RCODE_COMPLETE. */
1496 	orb->base.rcode = -1;
1497 	kref_init(&orb->base.kref);
1498 
1499 	orb->lu   = lu;
1500 	orb->done = done;
1501 	orb->cmd  = cmd;
1502 
1503 	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1504 	orb->request.misc = cpu_to_be32(
1505 		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1506 		COMMAND_ORB_SPEED(device->max_speed) |
1507 		COMMAND_ORB_NOTIFY);
1508 
1509 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1510 		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1511 
1512 	generation = device->generation;
1513 	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1514 
1515 	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1516 		goto out;
1517 
1518 	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1519 
1520 	orb->base.callback = complete_command_orb;
1521 	orb->base.request_bus =
1522 		dma_map_single(device->card->device, &orb->request,
1523 			       sizeof(orb->request), DMA_TO_DEVICE);
1524 	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1525 		sbp2_unmap_scatterlist(device->card->device, orb);
1526 		goto out;
1527 	}
1528 
1529 	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1530 		      lu->command_block_agent_address + SBP2_ORB_POINTER);
1531 	retval = 0;
1532  out:
1533 	kref_put(&orb->base.kref, free_orb);
1534 	return retval;
1535 }
1536 
1537 static DEF_SCSI_QCMD(sbp2_scsi_queuecommand)
1538 
1539 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1540 {
1541 	struct sbp2_logical_unit *lu = sdev->hostdata;
1542 
1543 	/* (Re-)Adding logical units via the SCSI stack is not supported. */
1544 	if (!lu)
1545 		return -ENOSYS;
1546 
1547 	sdev->allow_restart = 1;
1548 
1549 	/* SBP-2 requires quadlet alignment of the data buffers. */
1550 	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1551 
1552 	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1553 		sdev->inquiry_len = 36;
1554 
1555 	return 0;
1556 }
1557 
1558 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1559 {
1560 	struct sbp2_logical_unit *lu = sdev->hostdata;
1561 
1562 	sdev->use_10_for_rw = 1;
1563 
1564 	if (sbp2_param_exclusive_login)
1565 		sdev->manage_start_stop = 1;
1566 
1567 	if (sdev->type == TYPE_ROM)
1568 		sdev->use_10_for_ms = 1;
1569 
1570 	if (sdev->type == TYPE_DISK &&
1571 	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1572 		sdev->skip_ms_page_8 = 1;
1573 
1574 	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1575 		sdev->fix_capacity = 1;
1576 
1577 	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1578 		sdev->start_stop_pwr_cond = 1;
1579 
1580 	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1581 		blk_queue_max_hw_sectors(sdev->request_queue, 128 * 1024 / 512);
1582 
1583 	blk_queue_max_segment_size(sdev->request_queue, SBP2_MAX_SEG_SIZE);
1584 
1585 	return 0;
1586 }
1587 
1588 /*
1589  * Called by scsi stack when something has really gone wrong.  Usually
1590  * called when a command has timed-out for some reason.
1591  */
1592 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1593 {
1594 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1595 
1596 	fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1597 	sbp2_agent_reset(lu);
1598 	sbp2_cancel_orbs(lu);
1599 
1600 	return SUCCESS;
1601 }
1602 
1603 /*
1604  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1605  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1606  *
1607  * This is the concatenation of target port identifier and logical unit
1608  * identifier as per SAM-2...SAM-4 annex A.
1609  */
1610 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1611 			struct device_attribute *attr, char *buf)
1612 {
1613 	struct scsi_device *sdev = to_scsi_device(dev);
1614 	struct sbp2_logical_unit *lu;
1615 
1616 	if (!sdev)
1617 		return 0;
1618 
1619 	lu = sdev->hostdata;
1620 
1621 	return sprintf(buf, "%016llx:%06x:%04x\n",
1622 			(unsigned long long)lu->tgt->guid,
1623 			lu->tgt->directory_id, lu->lun);
1624 }
1625 
1626 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1627 
1628 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1629 	&dev_attr_ieee1394_id,
1630 	NULL
1631 };
1632 
1633 static struct scsi_host_template scsi_driver_template = {
1634 	.module			= THIS_MODULE,
1635 	.name			= "SBP-2 IEEE-1394",
1636 	.proc_name		= sbp2_driver_name,
1637 	.queuecommand		= sbp2_scsi_queuecommand,
1638 	.slave_alloc		= sbp2_scsi_slave_alloc,
1639 	.slave_configure	= sbp2_scsi_slave_configure,
1640 	.eh_abort_handler	= sbp2_scsi_abort,
1641 	.this_id		= -1,
1642 	.sg_tablesize		= SG_ALL,
1643 	.use_clustering		= ENABLE_CLUSTERING,
1644 	.cmd_per_lun		= 1,
1645 	.can_queue		= 1,
1646 	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
1647 };
1648 
1649 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1650 MODULE_DESCRIPTION("SCSI over IEEE1394");
1651 MODULE_LICENSE("GPL");
1652 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1653 
1654 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1655 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1656 MODULE_ALIAS("sbp2");
1657 #endif
1658 
1659 static int __init sbp2_init(void)
1660 {
1661 	sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1662 	if (!sbp2_wq)
1663 		return -ENOMEM;
1664 
1665 	return driver_register(&sbp2_driver.driver);
1666 }
1667 
1668 static void __exit sbp2_cleanup(void)
1669 {
1670 	driver_unregister(&sbp2_driver.driver);
1671 	destroy_workqueue(sbp2_wq);
1672 }
1673 
1674 module_init(sbp2_init);
1675 module_exit(sbp2_cleanup);
1676