xref: /linux/drivers/firewire/sbp2.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * SBP2 driver (SCSI over IEEE1394)
3  *
4  * Copyright (C) 2005-2007  Kristian Hoegsberg <krh@bitplanet.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software Foundation,
18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19  */
20 
21 /*
22  * The basic structure of this driver is based on the old storage driver,
23  * drivers/ieee1394/sbp2.c, originally written by
24  *     James Goodwin <jamesg@filanet.com>
25  * with later contributions and ongoing maintenance from
26  *     Ben Collins <bcollins@debian.org>,
27  *     Stefan Richter <stefanr@s5r6.in-berlin.de>
28  * and many others.
29  */
30 
31 #include <linux/blkdev.h>
32 #include <linux/bug.h>
33 #include <linux/completion.h>
34 #include <linux/delay.h>
35 #include <linux/device.h>
36 #include <linux/dma-mapping.h>
37 #include <linux/firewire.h>
38 #include <linux/firewire-constants.h>
39 #include <linux/init.h>
40 #include <linux/jiffies.h>
41 #include <linux/kernel.h>
42 #include <linux/kref.h>
43 #include <linux/list.h>
44 #include <linux/mod_devicetable.h>
45 #include <linux/module.h>
46 #include <linux/moduleparam.h>
47 #include <linux/scatterlist.h>
48 #include <linux/slab.h>
49 #include <linux/spinlock.h>
50 #include <linux/string.h>
51 #include <linux/stringify.h>
52 #include <linux/workqueue.h>
53 
54 #include <asm/byteorder.h>
55 
56 #include <scsi/scsi.h>
57 #include <scsi/scsi_cmnd.h>
58 #include <scsi/scsi_device.h>
59 #include <scsi/scsi_host.h>
60 
61 /*
62  * So far only bridges from Oxford Semiconductor are known to support
63  * concurrent logins. Depending on firmware, four or two concurrent logins
64  * are possible on OXFW911 and newer Oxsemi bridges.
65  *
66  * Concurrent logins are useful together with cluster filesystems.
67  */
68 static bool sbp2_param_exclusive_login = 1;
69 module_param_named(exclusive_login, sbp2_param_exclusive_login, bool, 0644);
70 MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
71 		 "(default = Y, use N for concurrent initiators)");
72 
73 /*
74  * Flags for firmware oddities
75  *
76  * - 128kB max transfer
77  *   Limit transfer size. Necessary for some old bridges.
78  *
79  * - 36 byte inquiry
80  *   When scsi_mod probes the device, let the inquiry command look like that
81  *   from MS Windows.
82  *
83  * - skip mode page 8
84  *   Suppress sending of mode_sense for mode page 8 if the device pretends to
85  *   support the SCSI Primary Block commands instead of Reduced Block Commands.
86  *
87  * - fix capacity
88  *   Tell sd_mod to correct the last sector number reported by read_capacity.
89  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
90  *   Don't use this with devices which don't have this bug.
91  *
92  * - delay inquiry
93  *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
94  *
95  * - power condition
96  *   Set the power condition field in the START STOP UNIT commands sent by
97  *   sd_mod on suspend, resume, and shutdown (if manage_start_stop is on).
98  *   Some disks need this to spin down or to resume properly.
99  *
100  * - override internal blacklist
101  *   Instead of adding to the built-in blacklist, use only the workarounds
102  *   specified in the module load parameter.
103  *   Useful if a blacklist entry interfered with a non-broken device.
104  */
105 #define SBP2_WORKAROUND_128K_MAX_TRANS	0x1
106 #define SBP2_WORKAROUND_INQUIRY_36	0x2
107 #define SBP2_WORKAROUND_MODE_SENSE_8	0x4
108 #define SBP2_WORKAROUND_FIX_CAPACITY	0x8
109 #define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
110 #define SBP2_INQUIRY_DELAY		12
111 #define SBP2_WORKAROUND_POWER_CONDITION	0x20
112 #define SBP2_WORKAROUND_OVERRIDE	0x100
113 
114 static int sbp2_param_workarounds;
115 module_param_named(workarounds, sbp2_param_workarounds, int, 0644);
116 MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
117 	", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
118 	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
119 	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
120 	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
121 	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
122 	", set power condition in start stop unit = "
123 				  __stringify(SBP2_WORKAROUND_POWER_CONDITION)
124 	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
125 	", or a combination)");
126 
127 /*
128  * We create one struct sbp2_logical_unit per SBP-2 Logical Unit Number Entry
129  * and one struct scsi_device per sbp2_logical_unit.
130  */
131 struct sbp2_logical_unit {
132 	struct sbp2_target *tgt;
133 	struct list_head link;
134 	struct fw_address_handler address_handler;
135 	struct list_head orb_list;
136 
137 	u64 command_block_agent_address;
138 	u16 lun;
139 	int login_id;
140 
141 	/*
142 	 * The generation is updated once we've logged in or reconnected
143 	 * to the logical unit.  Thus, I/O to the device will automatically
144 	 * fail and get retried if it happens in a window where the device
145 	 * is not ready, e.g. after a bus reset but before we reconnect.
146 	 */
147 	int generation;
148 	int retries;
149 	struct delayed_work work;
150 	bool has_sdev;
151 	bool blocked;
152 };
153 
154 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
155 {
156 	queue_delayed_work(fw_workqueue, &lu->work, delay);
157 }
158 
159 /*
160  * We create one struct sbp2_target per IEEE 1212 Unit Directory
161  * and one struct Scsi_Host per sbp2_target.
162  */
163 struct sbp2_target {
164 	struct fw_unit *unit;
165 	struct list_head lu_list;
166 
167 	u64 management_agent_address;
168 	u64 guid;
169 	int directory_id;
170 	int node_id;
171 	int address_high;
172 	unsigned int workarounds;
173 	unsigned int mgt_orb_timeout;
174 	unsigned int max_payload;
175 
176 	int dont_block;	/* counter for each logical unit */
177 	int blocked;	/* ditto */
178 };
179 
180 static struct fw_device *target_parent_device(struct sbp2_target *tgt)
181 {
182 	return fw_parent_device(tgt->unit);
183 }
184 
185 static const struct device *tgt_dev(const struct sbp2_target *tgt)
186 {
187 	return &tgt->unit->device;
188 }
189 
190 static const struct device *lu_dev(const struct sbp2_logical_unit *lu)
191 {
192 	return &lu->tgt->unit->device;
193 }
194 
195 /* Impossible login_id, to detect logout attempt before successful login */
196 #define INVALID_LOGIN_ID 0x10000
197 
198 #define SBP2_ORB_TIMEOUT		2000U		/* Timeout in ms */
199 #define SBP2_ORB_NULL			0x80000000
200 #define SBP2_RETRY_LIMIT		0xf		/* 15 retries */
201 #define SBP2_CYCLE_LIMIT		(0xc8 << 12)	/* 200 125us cycles */
202 
203 /*
204  * There is no transport protocol limit to the CDB length,  but we implement
205  * a fixed length only.  16 bytes is enough for disks larger than 2 TB.
206  */
207 #define SBP2_MAX_CDB_SIZE		16
208 
209 /*
210  * The maximum SBP-2 data buffer size is 0xffff.  We quadlet-align this
211  * for compatibility with earlier versions of this driver.
212  */
213 #define SBP2_MAX_SEG_SIZE		0xfffc
214 
215 /* Unit directory keys */
216 #define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
217 #define SBP2_CSR_FIRMWARE_REVISION	0x3c
218 #define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
219 #define SBP2_CSR_UNIT_UNIQUE_ID		0x8d
220 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY	0xd4
221 
222 /* Management orb opcodes */
223 #define SBP2_LOGIN_REQUEST		0x0
224 #define SBP2_QUERY_LOGINS_REQUEST	0x1
225 #define SBP2_RECONNECT_REQUEST		0x3
226 #define SBP2_SET_PASSWORD_REQUEST	0x4
227 #define SBP2_LOGOUT_REQUEST		0x7
228 #define SBP2_ABORT_TASK_REQUEST		0xb
229 #define SBP2_ABORT_TASK_SET		0xc
230 #define SBP2_LOGICAL_UNIT_RESET		0xe
231 #define SBP2_TARGET_RESET_REQUEST	0xf
232 
233 /* Offsets for command block agent registers */
234 #define SBP2_AGENT_STATE		0x00
235 #define SBP2_AGENT_RESET		0x04
236 #define SBP2_ORB_POINTER		0x08
237 #define SBP2_DOORBELL			0x10
238 #define SBP2_UNSOLICITED_STATUS_ENABLE	0x14
239 
240 /* Status write response codes */
241 #define SBP2_STATUS_REQUEST_COMPLETE	0x0
242 #define SBP2_STATUS_TRANSPORT_FAILURE	0x1
243 #define SBP2_STATUS_ILLEGAL_REQUEST	0x2
244 #define SBP2_STATUS_VENDOR_DEPENDENT	0x3
245 
246 #define STATUS_GET_ORB_HIGH(v)		((v).status & 0xffff)
247 #define STATUS_GET_SBP_STATUS(v)	(((v).status >> 16) & 0xff)
248 #define STATUS_GET_LEN(v)		(((v).status >> 24) & 0x07)
249 #define STATUS_GET_DEAD(v)		(((v).status >> 27) & 0x01)
250 #define STATUS_GET_RESPONSE(v)		(((v).status >> 28) & 0x03)
251 #define STATUS_GET_SOURCE(v)		(((v).status >> 30) & 0x03)
252 #define STATUS_GET_ORB_LOW(v)		((v).orb_low)
253 #define STATUS_GET_DATA(v)		((v).data)
254 
255 struct sbp2_status {
256 	u32 status;
257 	u32 orb_low;
258 	u8 data[24];
259 };
260 
261 struct sbp2_pointer {
262 	__be32 high;
263 	__be32 low;
264 };
265 
266 struct sbp2_orb {
267 	struct fw_transaction t;
268 	struct kref kref;
269 	dma_addr_t request_bus;
270 	int rcode;
271 	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
272 	struct list_head link;
273 };
274 
275 #define MANAGEMENT_ORB_LUN(v)			((v))
276 #define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
277 #define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
278 #define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
279 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
280 #define MANAGEMENT_ORB_NOTIFY			((1) << 31)
281 
282 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
283 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
284 
285 struct sbp2_management_orb {
286 	struct sbp2_orb base;
287 	struct {
288 		struct sbp2_pointer password;
289 		struct sbp2_pointer response;
290 		__be32 misc;
291 		__be32 length;
292 		struct sbp2_pointer status_fifo;
293 	} request;
294 	__be32 response[4];
295 	dma_addr_t response_bus;
296 	struct completion done;
297 	struct sbp2_status status;
298 };
299 
300 struct sbp2_login_response {
301 	__be32 misc;
302 	struct sbp2_pointer command_block_agent;
303 	__be32 reconnect_hold;
304 };
305 #define COMMAND_ORB_DATA_SIZE(v)	((v))
306 #define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
307 #define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
308 #define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
309 #define COMMAND_ORB_SPEED(v)		((v) << 24)
310 #define COMMAND_ORB_DIRECTION		((1) << 27)
311 #define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
312 #define COMMAND_ORB_NOTIFY		((1) << 31)
313 
314 struct sbp2_command_orb {
315 	struct sbp2_orb base;
316 	struct {
317 		struct sbp2_pointer next;
318 		struct sbp2_pointer data_descriptor;
319 		__be32 misc;
320 		u8 command_block[SBP2_MAX_CDB_SIZE];
321 	} request;
322 	struct scsi_cmnd *cmd;
323 	struct sbp2_logical_unit *lu;
324 
325 	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
326 	dma_addr_t page_table_bus;
327 };
328 
329 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
330 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
331 
332 /*
333  * List of devices with known bugs.
334  *
335  * The firmware_revision field, masked with 0xffff00, is the best
336  * indicator for the type of bridge chip of a device.  It yields a few
337  * false positives but this did not break correctly behaving devices
338  * so far.
339  */
340 static const struct {
341 	u32 firmware_revision;
342 	u32 model;
343 	unsigned int workarounds;
344 } sbp2_workarounds_table[] = {
345 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
346 		.firmware_revision	= 0x002800,
347 		.model			= 0x001010,
348 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
349 					  SBP2_WORKAROUND_MODE_SENSE_8 |
350 					  SBP2_WORKAROUND_POWER_CONDITION,
351 	},
352 	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
353 		.firmware_revision	= 0x002800,
354 		.model			= 0x000000,
355 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
356 	},
357 	/* Initio bridges, actually only needed for some older ones */ {
358 		.firmware_revision	= 0x000200,
359 		.model			= SBP2_ROM_VALUE_WILDCARD,
360 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
361 	},
362 	/* PL-3507 bridge with Prolific firmware */ {
363 		.firmware_revision	= 0x012800,
364 		.model			= SBP2_ROM_VALUE_WILDCARD,
365 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
366 	},
367 	/* Symbios bridge */ {
368 		.firmware_revision	= 0xa0b800,
369 		.model			= SBP2_ROM_VALUE_WILDCARD,
370 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
371 	},
372 	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
373 		.firmware_revision	= 0x002600,
374 		.model			= SBP2_ROM_VALUE_WILDCARD,
375 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
376 	},
377 	/*
378 	 * iPod 2nd generation: needs 128k max transfer size workaround
379 	 * iPod 3rd generation: needs fix capacity workaround
380 	 */
381 	{
382 		.firmware_revision	= 0x0a2700,
383 		.model			= 0x000000,
384 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
385 					  SBP2_WORKAROUND_FIX_CAPACITY,
386 	},
387 	/* iPod 4th generation */ {
388 		.firmware_revision	= 0x0a2700,
389 		.model			= 0x000021,
390 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
391 	},
392 	/* iPod mini */ {
393 		.firmware_revision	= 0x0a2700,
394 		.model			= 0x000022,
395 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
396 	},
397 	/* iPod mini */ {
398 		.firmware_revision	= 0x0a2700,
399 		.model			= 0x000023,
400 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
401 	},
402 	/* iPod Photo */ {
403 		.firmware_revision	= 0x0a2700,
404 		.model			= 0x00007e,
405 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
406 	}
407 };
408 
409 static void free_orb(struct kref *kref)
410 {
411 	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
412 
413 	kfree(orb);
414 }
415 
416 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
417 			      int tcode, int destination, int source,
418 			      int generation, unsigned long long offset,
419 			      void *payload, size_t length, void *callback_data)
420 {
421 	struct sbp2_logical_unit *lu = callback_data;
422 	struct sbp2_orb *orb;
423 	struct sbp2_status status;
424 	unsigned long flags;
425 
426 	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
427 	    length < 8 || length > sizeof(status)) {
428 		fw_send_response(card, request, RCODE_TYPE_ERROR);
429 		return;
430 	}
431 
432 	status.status  = be32_to_cpup(payload);
433 	status.orb_low = be32_to_cpup(payload + 4);
434 	memset(status.data, 0, sizeof(status.data));
435 	if (length > 8)
436 		memcpy(status.data, payload + 8, length - 8);
437 
438 	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
439 		dev_notice(lu_dev(lu),
440 			   "non-ORB related status write, not handled\n");
441 		fw_send_response(card, request, RCODE_COMPLETE);
442 		return;
443 	}
444 
445 	/* Lookup the orb corresponding to this status write. */
446 	spin_lock_irqsave(&card->lock, flags);
447 	list_for_each_entry(orb, &lu->orb_list, link) {
448 		if (STATUS_GET_ORB_HIGH(status) == 0 &&
449 		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
450 			orb->rcode = RCODE_COMPLETE;
451 			list_del(&orb->link);
452 			break;
453 		}
454 	}
455 	spin_unlock_irqrestore(&card->lock, flags);
456 
457 	if (&orb->link != &lu->orb_list) {
458 		orb->callback(orb, &status);
459 		kref_put(&orb->kref, free_orb); /* orb callback reference */
460 	} else {
461 		dev_err(lu_dev(lu), "status write for unknown ORB\n");
462 	}
463 
464 	fw_send_response(card, request, RCODE_COMPLETE);
465 }
466 
467 static void complete_transaction(struct fw_card *card, int rcode,
468 				 void *payload, size_t length, void *data)
469 {
470 	struct sbp2_orb *orb = data;
471 	unsigned long flags;
472 
473 	/*
474 	 * This is a little tricky.  We can get the status write for
475 	 * the orb before we get this callback.  The status write
476 	 * handler above will assume the orb pointer transaction was
477 	 * successful and set the rcode to RCODE_COMPLETE for the orb.
478 	 * So this callback only sets the rcode if it hasn't already
479 	 * been set and only does the cleanup if the transaction
480 	 * failed and we didn't already get a status write.
481 	 */
482 	spin_lock_irqsave(&card->lock, flags);
483 
484 	if (orb->rcode == -1)
485 		orb->rcode = rcode;
486 	if (orb->rcode != RCODE_COMPLETE) {
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_parent_device(lu->tgt);
503 	struct sbp2_pointer orb_pointer;
504 	unsigned long flags;
505 
506 	orb_pointer.high = 0;
507 	orb_pointer.low = cpu_to_be32(orb->request_bus);
508 
509 	spin_lock_irqsave(&device->card->lock, flags);
510 	list_add_tail(&orb->link, &lu->orb_list);
511 	spin_unlock_irqrestore(&device->card->lock, flags);
512 
513 	kref_get(&orb->kref); /* transaction callback reference */
514 	kref_get(&orb->kref); /* orb callback reference */
515 
516 	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
517 			node_id, generation, device->max_speed, offset,
518 			&orb_pointer, 8, complete_transaction, orb);
519 }
520 
521 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
522 {
523 	struct fw_device *device = target_parent_device(lu->tgt);
524 	struct sbp2_orb *orb, *next;
525 	struct list_head list;
526 	unsigned long flags;
527 	int retval = -ENOENT;
528 
529 	INIT_LIST_HEAD(&list);
530 	spin_lock_irqsave(&device->card->lock, flags);
531 	list_splice_init(&lu->orb_list, &list);
532 	spin_unlock_irqrestore(&device->card->lock, flags);
533 
534 	list_for_each_entry_safe(orb, next, &list, link) {
535 		retval = 0;
536 		if (fw_cancel_transaction(device->card, &orb->t) == 0)
537 			continue;
538 
539 		orb->rcode = RCODE_CANCELLED;
540 		orb->callback(orb, NULL);
541 		kref_put(&orb->kref, free_orb); /* orb callback reference */
542 	}
543 
544 	return retval;
545 }
546 
547 static void complete_management_orb(struct sbp2_orb *base_orb,
548 				    struct sbp2_status *status)
549 {
550 	struct sbp2_management_orb *orb =
551 		container_of(base_orb, struct sbp2_management_orb, base);
552 
553 	if (status)
554 		memcpy(&orb->status, status, sizeof(*status));
555 	complete(&orb->done);
556 }
557 
558 static int sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
559 				    int generation, int function,
560 				    int lun_or_login_id, void *response)
561 {
562 	struct fw_device *device = target_parent_device(lu->tgt);
563 	struct sbp2_management_orb *orb;
564 	unsigned int timeout;
565 	int retval = -ENOMEM;
566 
567 	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
568 		return 0;
569 
570 	orb = kzalloc(sizeof(*orb), GFP_NOIO);
571 	if (orb == NULL)
572 		return -ENOMEM;
573 
574 	kref_init(&orb->base.kref);
575 	orb->response_bus =
576 		dma_map_single(device->card->device, &orb->response,
577 			       sizeof(orb->response), DMA_FROM_DEVICE);
578 	if (dma_mapping_error(device->card->device, orb->response_bus))
579 		goto fail_mapping_response;
580 
581 	orb->request.response.high = 0;
582 	orb->request.response.low  = cpu_to_be32(orb->response_bus);
583 
584 	orb->request.misc = cpu_to_be32(
585 		MANAGEMENT_ORB_NOTIFY |
586 		MANAGEMENT_ORB_FUNCTION(function) |
587 		MANAGEMENT_ORB_LUN(lun_or_login_id));
588 	orb->request.length = cpu_to_be32(
589 		MANAGEMENT_ORB_RESPONSE_LENGTH(sizeof(orb->response)));
590 
591 	orb->request.status_fifo.high =
592 		cpu_to_be32(lu->address_handler.offset >> 32);
593 	orb->request.status_fifo.low  =
594 		cpu_to_be32(lu->address_handler.offset);
595 
596 	if (function == SBP2_LOGIN_REQUEST) {
597 		/* Ask for 2^2 == 4 seconds reconnect grace period */
598 		orb->request.misc |= cpu_to_be32(
599 			MANAGEMENT_ORB_RECONNECT(2) |
600 			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login));
601 		timeout = lu->tgt->mgt_orb_timeout;
602 	} else {
603 		timeout = SBP2_ORB_TIMEOUT;
604 	}
605 
606 	init_completion(&orb->done);
607 	orb->base.callback = complete_management_orb;
608 
609 	orb->base.request_bus =
610 		dma_map_single(device->card->device, &orb->request,
611 			       sizeof(orb->request), DMA_TO_DEVICE);
612 	if (dma_mapping_error(device->card->device, orb->base.request_bus))
613 		goto fail_mapping_request;
614 
615 	sbp2_send_orb(&orb->base, lu, node_id, generation,
616 		      lu->tgt->management_agent_address);
617 
618 	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
619 
620 	retval = -EIO;
621 	if (sbp2_cancel_orbs(lu) == 0) {
622 		dev_err(lu_dev(lu), "ORB reply timed out, rcode 0x%02x\n",
623 			orb->base.rcode);
624 		goto out;
625 	}
626 
627 	if (orb->base.rcode != RCODE_COMPLETE) {
628 		dev_err(lu_dev(lu), "management write failed, rcode 0x%02x\n",
629 			orb->base.rcode);
630 		goto out;
631 	}
632 
633 	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
634 	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
635 		dev_err(lu_dev(lu), "error status: %d:%d\n",
636 			 STATUS_GET_RESPONSE(orb->status),
637 			 STATUS_GET_SBP_STATUS(orb->status));
638 		goto out;
639 	}
640 
641 	retval = 0;
642  out:
643 	dma_unmap_single(device->card->device, orb->base.request_bus,
644 			 sizeof(orb->request), DMA_TO_DEVICE);
645  fail_mapping_request:
646 	dma_unmap_single(device->card->device, orb->response_bus,
647 			 sizeof(orb->response), DMA_FROM_DEVICE);
648  fail_mapping_response:
649 	if (response)
650 		memcpy(response, orb->response, sizeof(orb->response));
651 	kref_put(&orb->base.kref, free_orb);
652 
653 	return retval;
654 }
655 
656 static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
657 {
658 	struct fw_device *device = target_parent_device(lu->tgt);
659 	__be32 d = 0;
660 
661 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
662 			   lu->tgt->node_id, lu->generation, device->max_speed,
663 			   lu->command_block_agent_address + SBP2_AGENT_RESET,
664 			   &d, 4);
665 }
666 
667 static void complete_agent_reset_write_no_wait(struct fw_card *card,
668 		int rcode, void *payload, size_t length, void *data)
669 {
670 	kfree(data);
671 }
672 
673 static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
674 {
675 	struct fw_device *device = target_parent_device(lu->tgt);
676 	struct fw_transaction *t;
677 	static __be32 d;
678 
679 	t = kmalloc(sizeof(*t), GFP_ATOMIC);
680 	if (t == NULL)
681 		return;
682 
683 	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
684 			lu->tgt->node_id, lu->generation, device->max_speed,
685 			lu->command_block_agent_address + SBP2_AGENT_RESET,
686 			&d, 4, complete_agent_reset_write_no_wait, t);
687 }
688 
689 static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
690 {
691 	/*
692 	 * We may access dont_block without taking card->lock here:
693 	 * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
694 	 * are currently serialized against each other.
695 	 * And a wrong result in sbp2_conditionally_block()'s access of
696 	 * dont_block is rather harmless, it simply misses its first chance.
697 	 */
698 	--lu->tgt->dont_block;
699 }
700 
701 /*
702  * Blocks lu->tgt if all of the following conditions are met:
703  *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
704  *     logical units have been finished (indicated by dont_block == 0).
705  *   - lu->generation is stale.
706  *
707  * Note, scsi_block_requests() must be called while holding card->lock,
708  * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
709  * unblock the target.
710  */
711 static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
712 {
713 	struct sbp2_target *tgt = lu->tgt;
714 	struct fw_card *card = target_parent_device(tgt)->card;
715 	struct Scsi_Host *shost =
716 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
717 	unsigned long flags;
718 
719 	spin_lock_irqsave(&card->lock, flags);
720 	if (!tgt->dont_block && !lu->blocked &&
721 	    lu->generation != card->generation) {
722 		lu->blocked = true;
723 		if (++tgt->blocked == 1)
724 			scsi_block_requests(shost);
725 	}
726 	spin_unlock_irqrestore(&card->lock, flags);
727 }
728 
729 /*
730  * Unblocks lu->tgt as soon as all its logical units can be unblocked.
731  * Note, it is harmless to run scsi_unblock_requests() outside the
732  * card->lock protected section.  On the other hand, running it inside
733  * the section might clash with shost->host_lock.
734  */
735 static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
736 {
737 	struct sbp2_target *tgt = lu->tgt;
738 	struct fw_card *card = target_parent_device(tgt)->card;
739 	struct Scsi_Host *shost =
740 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
741 	unsigned long flags;
742 	bool unblock = false;
743 
744 	spin_lock_irqsave(&card->lock, flags);
745 	if (lu->blocked && lu->generation == card->generation) {
746 		lu->blocked = false;
747 		unblock = --tgt->blocked == 0;
748 	}
749 	spin_unlock_irqrestore(&card->lock, flags);
750 
751 	if (unblock)
752 		scsi_unblock_requests(shost);
753 }
754 
755 /*
756  * Prevents future blocking of tgt and unblocks it.
757  * Note, it is harmless to run scsi_unblock_requests() outside the
758  * card->lock protected section.  On the other hand, running it inside
759  * the section might clash with shost->host_lock.
760  */
761 static void sbp2_unblock(struct sbp2_target *tgt)
762 {
763 	struct fw_card *card = target_parent_device(tgt)->card;
764 	struct Scsi_Host *shost =
765 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
766 	unsigned long flags;
767 
768 	spin_lock_irqsave(&card->lock, flags);
769 	++tgt->dont_block;
770 	spin_unlock_irqrestore(&card->lock, flags);
771 
772 	scsi_unblock_requests(shost);
773 }
774 
775 static int sbp2_lun2int(u16 lun)
776 {
777 	struct scsi_lun eight_bytes_lun;
778 
779 	memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
780 	eight_bytes_lun.scsi_lun[0] = (lun >> 8) & 0xff;
781 	eight_bytes_lun.scsi_lun[1] = lun & 0xff;
782 
783 	return scsilun_to_int(&eight_bytes_lun);
784 }
785 
786 /*
787  * Write retransmit retry values into the BUSY_TIMEOUT register.
788  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
789  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
790  *   saner value after logging into the device.
791  * - The dual-phase retry protocol is optional to implement, and if not
792  *   supported, writes to the dual-phase portion of the register will be
793  *   ignored. We try to write the original 1394-1995 default here.
794  * - In the case of devices that are also SBP-3-compliant, all writes are
795  *   ignored, as the register is read-only, but contains single-phase retry of
796  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
797  *   write attempt is safe and yields more consistent behavior for all devices.
798  *
799  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
800  * and section 6.4 of the SBP-3 spec for further details.
801  */
802 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
803 {
804 	struct fw_device *device = target_parent_device(lu->tgt);
805 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
806 
807 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
808 			   lu->tgt->node_id, lu->generation, device->max_speed,
809 			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT, &d, 4);
810 }
811 
812 static void sbp2_reconnect(struct work_struct *work);
813 
814 static void sbp2_login(struct work_struct *work)
815 {
816 	struct sbp2_logical_unit *lu =
817 		container_of(work, struct sbp2_logical_unit, work.work);
818 	struct sbp2_target *tgt = lu->tgt;
819 	struct fw_device *device = target_parent_device(tgt);
820 	struct Scsi_Host *shost;
821 	struct scsi_device *sdev;
822 	struct sbp2_login_response response;
823 	int generation, node_id, local_node_id;
824 
825 	if (fw_device_is_shutdown(device))
826 		return;
827 
828 	generation    = device->generation;
829 	smp_rmb();    /* node IDs must not be older than generation */
830 	node_id       = device->node_id;
831 	local_node_id = device->card->node_id;
832 
833 	/* If this is a re-login attempt, log out, or we might be rejected. */
834 	if (lu->has_sdev)
835 		sbp2_send_management_orb(lu, device->node_id, generation,
836 				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
837 
838 	if (sbp2_send_management_orb(lu, node_id, generation,
839 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
840 		if (lu->retries++ < 5) {
841 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
842 		} else {
843 			dev_err(tgt_dev(tgt), "failed to login to LUN %04x\n",
844 				lu->lun);
845 			/* Let any waiting I/O fail from now on. */
846 			sbp2_unblock(lu->tgt);
847 		}
848 		return;
849 	}
850 
851 	tgt->node_id	  = node_id;
852 	tgt->address_high = local_node_id << 16;
853 	smp_wmb();	  /* node IDs must not be older than generation */
854 	lu->generation	  = generation;
855 
856 	lu->command_block_agent_address =
857 		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
858 		      << 32) | be32_to_cpu(response.command_block_agent.low);
859 	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
860 
861 	dev_notice(tgt_dev(tgt), "logged in to LUN %04x (%d retries)\n",
862 		   lu->lun, lu->retries);
863 
864 	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
865 	sbp2_set_busy_timeout(lu);
866 
867 	PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
868 	sbp2_agent_reset(lu);
869 
870 	/* This was a re-login. */
871 	if (lu->has_sdev) {
872 		sbp2_cancel_orbs(lu);
873 		sbp2_conditionally_unblock(lu);
874 
875 		return;
876 	}
877 
878 	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
879 		ssleep(SBP2_INQUIRY_DELAY);
880 
881 	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
882 	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
883 	/*
884 	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
885 	 * Therefore __scsi_add_device() will get into trouble if a bus reset
886 	 * happens in parallel.  It will either fail or leave us with an
887 	 * unusable sdev.  As a workaround we check for this and retry the
888 	 * whole login and SCSI probing.
889 	 */
890 
891 	/* Reported error during __scsi_add_device() */
892 	if (IS_ERR(sdev))
893 		goto out_logout_login;
894 
895 	/* Unreported error during __scsi_add_device() */
896 	smp_rmb(); /* get current card generation */
897 	if (generation != device->card->generation) {
898 		scsi_remove_device(sdev);
899 		scsi_device_put(sdev);
900 		goto out_logout_login;
901 	}
902 
903 	/* No error during __scsi_add_device() */
904 	lu->has_sdev = true;
905 	scsi_device_put(sdev);
906 	sbp2_allow_block(lu);
907 
908 	return;
909 
910  out_logout_login:
911 	smp_rmb(); /* generation may have changed */
912 	generation = device->generation;
913 	smp_rmb(); /* node_id must not be older than generation */
914 
915 	sbp2_send_management_orb(lu, device->node_id, generation,
916 				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
917 	/*
918 	 * If a bus reset happened, sbp2_update will have requeued
919 	 * lu->work already.  Reset the work from reconnect to login.
920 	 */
921 	PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
922 }
923 
924 static void sbp2_reconnect(struct work_struct *work)
925 {
926 	struct sbp2_logical_unit *lu =
927 		container_of(work, struct sbp2_logical_unit, work.work);
928 	struct sbp2_target *tgt = lu->tgt;
929 	struct fw_device *device = target_parent_device(tgt);
930 	int generation, node_id, local_node_id;
931 
932 	if (fw_device_is_shutdown(device))
933 		return;
934 
935 	generation    = device->generation;
936 	smp_rmb();    /* node IDs must not be older than generation */
937 	node_id       = device->node_id;
938 	local_node_id = device->card->node_id;
939 
940 	if (sbp2_send_management_orb(lu, node_id, generation,
941 				     SBP2_RECONNECT_REQUEST,
942 				     lu->login_id, NULL) < 0) {
943 		/*
944 		 * If reconnect was impossible even though we are in the
945 		 * current generation, fall back and try to log in again.
946 		 *
947 		 * We could check for "Function rejected" status, but
948 		 * looking at the bus generation as simpler and more general.
949 		 */
950 		smp_rmb(); /* get current card generation */
951 		if (generation == device->card->generation ||
952 		    lu->retries++ >= 5) {
953 			dev_err(tgt_dev(tgt), "failed to reconnect\n");
954 			lu->retries = 0;
955 			PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
956 		}
957 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
958 
959 		return;
960 	}
961 
962 	tgt->node_id      = node_id;
963 	tgt->address_high = local_node_id << 16;
964 	smp_wmb();	  /* node IDs must not be older than generation */
965 	lu->generation	  = generation;
966 
967 	dev_notice(tgt_dev(tgt), "reconnected to LUN %04x (%d retries)\n",
968 		   lu->lun, lu->retries);
969 
970 	sbp2_agent_reset(lu);
971 	sbp2_cancel_orbs(lu);
972 	sbp2_conditionally_unblock(lu);
973 }
974 
975 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
976 {
977 	struct sbp2_logical_unit *lu;
978 
979 	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
980 	if (!lu)
981 		return -ENOMEM;
982 
983 	lu->address_handler.length           = 0x100;
984 	lu->address_handler.address_callback = sbp2_status_write;
985 	lu->address_handler.callback_data    = lu;
986 
987 	if (fw_core_add_address_handler(&lu->address_handler,
988 					&fw_high_memory_region) < 0) {
989 		kfree(lu);
990 		return -ENOMEM;
991 	}
992 
993 	lu->tgt      = tgt;
994 	lu->lun      = lun_entry & 0xffff;
995 	lu->login_id = INVALID_LOGIN_ID;
996 	lu->retries  = 0;
997 	lu->has_sdev = false;
998 	lu->blocked  = false;
999 	++tgt->dont_block;
1000 	INIT_LIST_HEAD(&lu->orb_list);
1001 	INIT_DELAYED_WORK(&lu->work, sbp2_login);
1002 
1003 	list_add_tail(&lu->link, &tgt->lu_list);
1004 	return 0;
1005 }
1006 
1007 static void sbp2_get_unit_unique_id(struct sbp2_target *tgt,
1008 				    const u32 *leaf)
1009 {
1010 	if ((leaf[0] & 0xffff0000) == 0x00020000)
1011 		tgt->guid = (u64)leaf[1] << 32 | leaf[2];
1012 }
1013 
1014 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
1015 				      const u32 *directory)
1016 {
1017 	struct fw_csr_iterator ci;
1018 	int key, value;
1019 
1020 	fw_csr_iterator_init(&ci, directory);
1021 	while (fw_csr_iterator_next(&ci, &key, &value))
1022 		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1023 		    sbp2_add_logical_unit(tgt, value) < 0)
1024 			return -ENOMEM;
1025 	return 0;
1026 }
1027 
1028 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
1029 			      u32 *model, u32 *firmware_revision)
1030 {
1031 	struct fw_csr_iterator ci;
1032 	int key, value;
1033 
1034 	fw_csr_iterator_init(&ci, directory);
1035 	while (fw_csr_iterator_next(&ci, &key, &value)) {
1036 		switch (key) {
1037 
1038 		case CSR_DEPENDENT_INFO | CSR_OFFSET:
1039 			tgt->management_agent_address =
1040 					CSR_REGISTER_BASE + 4 * value;
1041 			break;
1042 
1043 		case CSR_DIRECTORY_ID:
1044 			tgt->directory_id = value;
1045 			break;
1046 
1047 		case CSR_MODEL:
1048 			*model = value;
1049 			break;
1050 
1051 		case SBP2_CSR_FIRMWARE_REVISION:
1052 			*firmware_revision = value;
1053 			break;
1054 
1055 		case SBP2_CSR_UNIT_CHARACTERISTICS:
1056 			/* the timeout value is stored in 500ms units */
1057 			tgt->mgt_orb_timeout = (value >> 8 & 0xff) * 500;
1058 			break;
1059 
1060 		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1061 			if (sbp2_add_logical_unit(tgt, value) < 0)
1062 				return -ENOMEM;
1063 			break;
1064 
1065 		case SBP2_CSR_UNIT_UNIQUE_ID:
1066 			sbp2_get_unit_unique_id(tgt, ci.p - 1 + value);
1067 			break;
1068 
1069 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1070 			/* Adjust for the increment in the iterator */
1071 			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1072 				return -ENOMEM;
1073 			break;
1074 		}
1075 	}
1076 	return 0;
1077 }
1078 
1079 /*
1080  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
1081  * provided in the config rom. Most devices do provide a value, which
1082  * we'll use for login management orbs, but with some sane limits.
1083  */
1084 static void sbp2_clamp_management_orb_timeout(struct sbp2_target *tgt)
1085 {
1086 	unsigned int timeout = tgt->mgt_orb_timeout;
1087 
1088 	if (timeout > 40000)
1089 		dev_notice(tgt_dev(tgt), "%ds mgt_ORB_timeout limited to 40s\n",
1090 			   timeout / 1000);
1091 
1092 	tgt->mgt_orb_timeout = clamp_val(timeout, 5000, 40000);
1093 }
1094 
1095 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1096 				  u32 firmware_revision)
1097 {
1098 	int i;
1099 	unsigned int w = sbp2_param_workarounds;
1100 
1101 	if (w)
1102 		dev_notice(tgt_dev(tgt),
1103 			   "Please notify linux1394-devel@lists.sf.net "
1104 			   "if you need the workarounds parameter\n");
1105 
1106 	if (w & SBP2_WORKAROUND_OVERRIDE)
1107 		goto out;
1108 
1109 	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1110 
1111 		if (sbp2_workarounds_table[i].firmware_revision !=
1112 		    (firmware_revision & 0xffffff00))
1113 			continue;
1114 
1115 		if (sbp2_workarounds_table[i].model != model &&
1116 		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1117 			continue;
1118 
1119 		w |= sbp2_workarounds_table[i].workarounds;
1120 		break;
1121 	}
1122  out:
1123 	if (w)
1124 		dev_notice(tgt_dev(tgt), "workarounds 0x%x "
1125 			   "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1126 			   w, firmware_revision, model);
1127 	tgt->workarounds = w;
1128 }
1129 
1130 static struct scsi_host_template scsi_driver_template;
1131 static void sbp2_remove(struct fw_unit *unit);
1132 
1133 static int sbp2_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
1134 {
1135 	struct fw_device *device = fw_parent_device(unit);
1136 	struct sbp2_target *tgt;
1137 	struct sbp2_logical_unit *lu;
1138 	struct Scsi_Host *shost;
1139 	u32 model, firmware_revision;
1140 
1141 	/* cannot (or should not) handle targets on the local node */
1142 	if (device->is_local)
1143 		return -ENODEV;
1144 
1145 	if (dma_get_max_seg_size(device->card->device) > SBP2_MAX_SEG_SIZE)
1146 		WARN_ON(dma_set_max_seg_size(device->card->device,
1147 					     SBP2_MAX_SEG_SIZE));
1148 
1149 	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1150 	if (shost == NULL)
1151 		return -ENOMEM;
1152 
1153 	tgt = (struct sbp2_target *)shost->hostdata;
1154 	dev_set_drvdata(&unit->device, tgt);
1155 	tgt->unit = unit;
1156 	INIT_LIST_HEAD(&tgt->lu_list);
1157 	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1158 
1159 	if (fw_device_enable_phys_dma(device) < 0)
1160 		goto fail_shost_put;
1161 
1162 	shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1163 
1164 	if (scsi_add_host_with_dma(shost, &unit->device,
1165 				   device->card->device) < 0)
1166 		goto fail_shost_put;
1167 
1168 	/* implicit directory ID */
1169 	tgt->directory_id = ((unit->directory - device->config_rom) * 4
1170 			     + CSR_CONFIG_ROM) & 0xffffff;
1171 
1172 	firmware_revision = SBP2_ROM_VALUE_MISSING;
1173 	model		  = SBP2_ROM_VALUE_MISSING;
1174 
1175 	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1176 			       &firmware_revision) < 0)
1177 		goto fail_remove;
1178 
1179 	sbp2_clamp_management_orb_timeout(tgt);
1180 	sbp2_init_workarounds(tgt, model, firmware_revision);
1181 
1182 	/*
1183 	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1184 	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
1185 	 * specifies the max payload size as 2 ^ (max_payload + 2), so
1186 	 * if we set this to max_speed + 7, we get the right value.
1187 	 */
1188 	tgt->max_payload = min3(device->max_speed + 7, 10U,
1189 				device->card->max_receive - 1);
1190 
1191 	/* Do the login in a workqueue so we can easily reschedule retries. */
1192 	list_for_each_entry(lu, &tgt->lu_list, link)
1193 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1194 
1195 	return 0;
1196 
1197  fail_remove:
1198 	sbp2_remove(unit);
1199 	return -ENOMEM;
1200 
1201  fail_shost_put:
1202 	scsi_host_put(shost);
1203 	return -ENOMEM;
1204 }
1205 
1206 static void sbp2_update(struct fw_unit *unit)
1207 {
1208 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1209 	struct sbp2_logical_unit *lu;
1210 
1211 	fw_device_enable_phys_dma(fw_parent_device(unit));
1212 
1213 	/*
1214 	 * Fw-core serializes sbp2_update() against sbp2_remove().
1215 	 * Iteration over tgt->lu_list is therefore safe here.
1216 	 */
1217 	list_for_each_entry(lu, &tgt->lu_list, link) {
1218 		sbp2_conditionally_block(lu);
1219 		lu->retries = 0;
1220 		sbp2_queue_work(lu, 0);
1221 	}
1222 }
1223 
1224 static void sbp2_remove(struct fw_unit *unit)
1225 {
1226 	struct fw_device *device = fw_parent_device(unit);
1227 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1228 	struct sbp2_logical_unit *lu, *next;
1229 	struct Scsi_Host *shost =
1230 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
1231 	struct scsi_device *sdev;
1232 
1233 	/* prevent deadlocks */
1234 	sbp2_unblock(tgt);
1235 
1236 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
1237 		cancel_delayed_work_sync(&lu->work);
1238 		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
1239 		if (sdev) {
1240 			scsi_remove_device(sdev);
1241 			scsi_device_put(sdev);
1242 		}
1243 		if (lu->login_id != INVALID_LOGIN_ID) {
1244 			int generation, node_id;
1245 			/*
1246 			 * tgt->node_id may be obsolete here if we failed
1247 			 * during initial login or after a bus reset where
1248 			 * the topology changed.
1249 			 */
1250 			generation = device->generation;
1251 			smp_rmb(); /* node_id vs. generation */
1252 			node_id    = device->node_id;
1253 			sbp2_send_management_orb(lu, node_id, generation,
1254 						 SBP2_LOGOUT_REQUEST,
1255 						 lu->login_id, NULL);
1256 		}
1257 		fw_core_remove_address_handler(&lu->address_handler);
1258 		list_del(&lu->link);
1259 		kfree(lu);
1260 	}
1261 	scsi_remove_host(shost);
1262 	dev_notice(&unit->device, "released target %d:0:0\n", shost->host_no);
1263 
1264 	scsi_host_put(shost);
1265 }
1266 
1267 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
1268 #define SBP2_SW_VERSION_ENTRY	0x00010483
1269 
1270 static const struct ieee1394_device_id sbp2_id_table[] = {
1271 	{
1272 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1273 				IEEE1394_MATCH_VERSION,
1274 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1275 		.version      = SBP2_SW_VERSION_ENTRY,
1276 	},
1277 	{ }
1278 };
1279 
1280 static struct fw_driver sbp2_driver = {
1281 	.driver   = {
1282 		.owner  = THIS_MODULE,
1283 		.name   = KBUILD_MODNAME,
1284 		.bus    = &fw_bus_type,
1285 	},
1286 	.probe    = sbp2_probe,
1287 	.update   = sbp2_update,
1288 	.remove   = sbp2_remove,
1289 	.id_table = sbp2_id_table,
1290 };
1291 
1292 static void sbp2_unmap_scatterlist(struct device *card_device,
1293 				   struct sbp2_command_orb *orb)
1294 {
1295 	scsi_dma_unmap(orb->cmd);
1296 
1297 	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1298 		dma_unmap_single(card_device, orb->page_table_bus,
1299 				 sizeof(orb->page_table), DMA_TO_DEVICE);
1300 }
1301 
1302 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1303 {
1304 	int sam_status;
1305 	int sfmt = (sbp2_status[0] >> 6) & 0x03;
1306 
1307 	if (sfmt == 2 || sfmt == 3) {
1308 		/*
1309 		 * Reserved for future standardization (2) or
1310 		 * Status block format vendor-dependent (3)
1311 		 */
1312 		return DID_ERROR << 16;
1313 	}
1314 
1315 	sense_data[0] = 0x70 | sfmt | (sbp2_status[1] & 0x80);
1316 	sense_data[1] = 0x0;
1317 	sense_data[2] = ((sbp2_status[1] << 1) & 0xe0) | (sbp2_status[1] & 0x0f);
1318 	sense_data[3] = sbp2_status[4];
1319 	sense_data[4] = sbp2_status[5];
1320 	sense_data[5] = sbp2_status[6];
1321 	sense_data[6] = sbp2_status[7];
1322 	sense_data[7] = 10;
1323 	sense_data[8] = sbp2_status[8];
1324 	sense_data[9] = sbp2_status[9];
1325 	sense_data[10] = sbp2_status[10];
1326 	sense_data[11] = sbp2_status[11];
1327 	sense_data[12] = sbp2_status[2];
1328 	sense_data[13] = sbp2_status[3];
1329 	sense_data[14] = sbp2_status[12];
1330 	sense_data[15] = sbp2_status[13];
1331 
1332 	sam_status = sbp2_status[0] & 0x3f;
1333 
1334 	switch (sam_status) {
1335 	case SAM_STAT_GOOD:
1336 	case SAM_STAT_CHECK_CONDITION:
1337 	case SAM_STAT_CONDITION_MET:
1338 	case SAM_STAT_BUSY:
1339 	case SAM_STAT_RESERVATION_CONFLICT:
1340 	case SAM_STAT_COMMAND_TERMINATED:
1341 		return DID_OK << 16 | sam_status;
1342 
1343 	default:
1344 		return DID_ERROR << 16;
1345 	}
1346 }
1347 
1348 static void complete_command_orb(struct sbp2_orb *base_orb,
1349 				 struct sbp2_status *status)
1350 {
1351 	struct sbp2_command_orb *orb =
1352 		container_of(base_orb, struct sbp2_command_orb, base);
1353 	struct fw_device *device = target_parent_device(orb->lu->tgt);
1354 	int result;
1355 
1356 	if (status != NULL) {
1357 		if (STATUS_GET_DEAD(*status))
1358 			sbp2_agent_reset_no_wait(orb->lu);
1359 
1360 		switch (STATUS_GET_RESPONSE(*status)) {
1361 		case SBP2_STATUS_REQUEST_COMPLETE:
1362 			result = DID_OK << 16;
1363 			break;
1364 		case SBP2_STATUS_TRANSPORT_FAILURE:
1365 			result = DID_BUS_BUSY << 16;
1366 			break;
1367 		case SBP2_STATUS_ILLEGAL_REQUEST:
1368 		case SBP2_STATUS_VENDOR_DEPENDENT:
1369 		default:
1370 			result = DID_ERROR << 16;
1371 			break;
1372 		}
1373 
1374 		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1375 			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1376 							   orb->cmd->sense_buffer);
1377 	} else {
1378 		/*
1379 		 * If the orb completes with status == NULL, something
1380 		 * went wrong, typically a bus reset happened mid-orb
1381 		 * or when sending the write (less likely).
1382 		 */
1383 		result = DID_BUS_BUSY << 16;
1384 		sbp2_conditionally_block(orb->lu);
1385 	}
1386 
1387 	dma_unmap_single(device->card->device, orb->base.request_bus,
1388 			 sizeof(orb->request), DMA_TO_DEVICE);
1389 	sbp2_unmap_scatterlist(device->card->device, orb);
1390 
1391 	orb->cmd->result = result;
1392 	orb->cmd->scsi_done(orb->cmd);
1393 }
1394 
1395 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1396 		struct fw_device *device, struct sbp2_logical_unit *lu)
1397 {
1398 	struct scatterlist *sg = scsi_sglist(orb->cmd);
1399 	int i, n;
1400 
1401 	n = scsi_dma_map(orb->cmd);
1402 	if (n <= 0)
1403 		goto fail;
1404 
1405 	/*
1406 	 * Handle the special case where there is only one element in
1407 	 * the scatter list by converting it to an immediate block
1408 	 * request. This is also a workaround for broken devices such
1409 	 * as the second generation iPod which doesn't support page
1410 	 * tables.
1411 	 */
1412 	if (n == 1) {
1413 		orb->request.data_descriptor.high =
1414 			cpu_to_be32(lu->tgt->address_high);
1415 		orb->request.data_descriptor.low  =
1416 			cpu_to_be32(sg_dma_address(sg));
1417 		orb->request.misc |=
1418 			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1419 		return 0;
1420 	}
1421 
1422 	for_each_sg(sg, sg, n, i) {
1423 		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1424 		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1425 	}
1426 
1427 	orb->page_table_bus =
1428 		dma_map_single(device->card->device, orb->page_table,
1429 			       sizeof(orb->page_table), DMA_TO_DEVICE);
1430 	if (dma_mapping_error(device->card->device, orb->page_table_bus))
1431 		goto fail_page_table;
1432 
1433 	/*
1434 	 * The data_descriptor pointer is the one case where we need
1435 	 * to fill in the node ID part of the address.  All other
1436 	 * pointers assume that the data referenced reside on the
1437 	 * initiator (i.e. us), but data_descriptor can refer to data
1438 	 * on other nodes so we need to put our ID in descriptor.high.
1439 	 */
1440 	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1441 	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1442 	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1443 					 COMMAND_ORB_DATA_SIZE(n));
1444 
1445 	return 0;
1446 
1447  fail_page_table:
1448 	scsi_dma_unmap(orb->cmd);
1449  fail:
1450 	return -ENOMEM;
1451 }
1452 
1453 /* SCSI stack integration */
1454 
1455 static int sbp2_scsi_queuecommand(struct Scsi_Host *shost,
1456 				  struct scsi_cmnd *cmd)
1457 {
1458 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1459 	struct fw_device *device = target_parent_device(lu->tgt);
1460 	struct sbp2_command_orb *orb;
1461 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1462 
1463 	/*
1464 	 * Bidirectional commands are not yet implemented, and unknown
1465 	 * transfer direction not handled.
1466 	 */
1467 	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1468 		dev_err(lu_dev(lu), "cannot handle bidirectional command\n");
1469 		cmd->result = DID_ERROR << 16;
1470 		cmd->scsi_done(cmd);
1471 		return 0;
1472 	}
1473 
1474 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1475 	if (orb == NULL)
1476 		return SCSI_MLQUEUE_HOST_BUSY;
1477 
1478 	/* Initialize rcode to something not RCODE_COMPLETE. */
1479 	orb->base.rcode = -1;
1480 	kref_init(&orb->base.kref);
1481 	orb->lu = lu;
1482 	orb->cmd = cmd;
1483 	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1484 	orb->request.misc = cpu_to_be32(
1485 		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1486 		COMMAND_ORB_SPEED(device->max_speed) |
1487 		COMMAND_ORB_NOTIFY);
1488 
1489 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1490 		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1491 
1492 	generation = device->generation;
1493 	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1494 
1495 	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1496 		goto out;
1497 
1498 	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1499 
1500 	orb->base.callback = complete_command_orb;
1501 	orb->base.request_bus =
1502 		dma_map_single(device->card->device, &orb->request,
1503 			       sizeof(orb->request), DMA_TO_DEVICE);
1504 	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1505 		sbp2_unmap_scatterlist(device->card->device, orb);
1506 		goto out;
1507 	}
1508 
1509 	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1510 		      lu->command_block_agent_address + SBP2_ORB_POINTER);
1511 	retval = 0;
1512  out:
1513 	kref_put(&orb->base.kref, free_orb);
1514 	return retval;
1515 }
1516 
1517 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1518 {
1519 	struct sbp2_logical_unit *lu = sdev->hostdata;
1520 
1521 	/* (Re-)Adding logical units via the SCSI stack is not supported. */
1522 	if (!lu)
1523 		return -ENOSYS;
1524 
1525 	sdev->allow_restart = 1;
1526 
1527 	/*
1528 	 * SBP-2 does not require any alignment, but we set it anyway
1529 	 * for compatibility with earlier versions of this driver.
1530 	 */
1531 	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1532 
1533 	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1534 		sdev->inquiry_len = 36;
1535 
1536 	return 0;
1537 }
1538 
1539 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1540 {
1541 	struct sbp2_logical_unit *lu = sdev->hostdata;
1542 
1543 	sdev->use_10_for_rw = 1;
1544 
1545 	if (sbp2_param_exclusive_login)
1546 		sdev->manage_start_stop = 1;
1547 
1548 	if (sdev->type == TYPE_ROM)
1549 		sdev->use_10_for_ms = 1;
1550 
1551 	if (sdev->type == TYPE_DISK &&
1552 	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1553 		sdev->skip_ms_page_8 = 1;
1554 
1555 	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1556 		sdev->fix_capacity = 1;
1557 
1558 	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1559 		sdev->start_stop_pwr_cond = 1;
1560 
1561 	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1562 		blk_queue_max_hw_sectors(sdev->request_queue, 128 * 1024 / 512);
1563 
1564 	return 0;
1565 }
1566 
1567 /*
1568  * Called by scsi stack when something has really gone wrong.  Usually
1569  * called when a command has timed-out for some reason.
1570  */
1571 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1572 {
1573 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1574 
1575 	dev_notice(lu_dev(lu), "sbp2_scsi_abort\n");
1576 	sbp2_agent_reset(lu);
1577 	sbp2_cancel_orbs(lu);
1578 
1579 	return SUCCESS;
1580 }
1581 
1582 /*
1583  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1584  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1585  *
1586  * This is the concatenation of target port identifier and logical unit
1587  * identifier as per SAM-2...SAM-4 annex A.
1588  */
1589 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1590 			struct device_attribute *attr, char *buf)
1591 {
1592 	struct scsi_device *sdev = to_scsi_device(dev);
1593 	struct sbp2_logical_unit *lu;
1594 
1595 	if (!sdev)
1596 		return 0;
1597 
1598 	lu = sdev->hostdata;
1599 
1600 	return sprintf(buf, "%016llx:%06x:%04x\n",
1601 			(unsigned long long)lu->tgt->guid,
1602 			lu->tgt->directory_id, lu->lun);
1603 }
1604 
1605 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1606 
1607 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1608 	&dev_attr_ieee1394_id,
1609 	NULL
1610 };
1611 
1612 static struct scsi_host_template scsi_driver_template = {
1613 	.module			= THIS_MODULE,
1614 	.name			= "SBP-2 IEEE-1394",
1615 	.proc_name		= "sbp2",
1616 	.queuecommand		= sbp2_scsi_queuecommand,
1617 	.slave_alloc		= sbp2_scsi_slave_alloc,
1618 	.slave_configure	= sbp2_scsi_slave_configure,
1619 	.eh_abort_handler	= sbp2_scsi_abort,
1620 	.this_id		= -1,
1621 	.sg_tablesize		= SG_ALL,
1622 	.use_clustering		= ENABLE_CLUSTERING,
1623 	.cmd_per_lun		= 1,
1624 	.can_queue		= 1,
1625 	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
1626 };
1627 
1628 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1629 MODULE_DESCRIPTION("SCSI over IEEE1394");
1630 MODULE_LICENSE("GPL");
1631 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1632 
1633 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1634 MODULE_ALIAS("sbp2");
1635 
1636 static int __init sbp2_init(void)
1637 {
1638 	return driver_register(&sbp2_driver.driver);
1639 }
1640 
1641 static void __exit sbp2_cleanup(void)
1642 {
1643 	driver_unregister(&sbp2_driver.driver);
1644 }
1645 
1646 module_init(sbp2_init);
1647 module_exit(sbp2_cleanup);
1648