xref: /openbmc/linux/drivers/firewire/sbp2.c (revision e8e0929d)
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 /*
192  * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
193  * provided in the config rom. Most devices do provide a value, which
194  * we'll use for login management orbs, but with some sane limits.
195  */
196 #define SBP2_MIN_LOGIN_ORB_TIMEOUT	5000U	/* Timeout in ms */
197 #define SBP2_MAX_LOGIN_ORB_TIMEOUT	40000U	/* Timeout in ms */
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 default maximum s/g segment size of a FireWire controller is
211  * usually 0x10000, but SBP-2 only allows 0xffff. Since buffers have to
212  * be quadlet-aligned, we set the length limit to 0xffff & ~3.
213  */
214 #define SBP2_MAX_SEG_SIZE		0xfffc
215 
216 /* Unit directory keys */
217 #define SBP2_CSR_UNIT_CHARACTERISTICS	0x3a
218 #define SBP2_CSR_FIRMWARE_REVISION	0x3c
219 #define SBP2_CSR_LOGICAL_UNIT_NUMBER	0x14
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 	struct sbp2_pointer pointer;
272 	void (*callback)(struct sbp2_orb * orb, struct sbp2_status * status);
273 	struct list_head link;
274 };
275 
276 #define MANAGEMENT_ORB_LUN(v)			((v))
277 #define MANAGEMENT_ORB_FUNCTION(v)		((v) << 16)
278 #define MANAGEMENT_ORB_RECONNECT(v)		((v) << 20)
279 #define MANAGEMENT_ORB_EXCLUSIVE(v)		((v) ? 1 << 28 : 0)
280 #define MANAGEMENT_ORB_REQUEST_FORMAT(v)	((v) << 29)
281 #define MANAGEMENT_ORB_NOTIFY			((1) << 31)
282 
283 #define MANAGEMENT_ORB_RESPONSE_LENGTH(v)	((v))
284 #define MANAGEMENT_ORB_PASSWORD_LENGTH(v)	((v) << 16)
285 
286 struct sbp2_management_orb {
287 	struct sbp2_orb base;
288 	struct {
289 		struct sbp2_pointer password;
290 		struct sbp2_pointer response;
291 		__be32 misc;
292 		__be32 length;
293 		struct sbp2_pointer status_fifo;
294 	} request;
295 	__be32 response[4];
296 	dma_addr_t response_bus;
297 	struct completion done;
298 	struct sbp2_status status;
299 };
300 
301 struct sbp2_login_response {
302 	__be32 misc;
303 	struct sbp2_pointer command_block_agent;
304 	__be32 reconnect_hold;
305 };
306 #define COMMAND_ORB_DATA_SIZE(v)	((v))
307 #define COMMAND_ORB_PAGE_SIZE(v)	((v) << 16)
308 #define COMMAND_ORB_PAGE_TABLE_PRESENT	((1) << 19)
309 #define COMMAND_ORB_MAX_PAYLOAD(v)	((v) << 20)
310 #define COMMAND_ORB_SPEED(v)		((v) << 24)
311 #define COMMAND_ORB_DIRECTION		((1) << 27)
312 #define COMMAND_ORB_REQUEST_FORMAT(v)	((v) << 29)
313 #define COMMAND_ORB_NOTIFY		((1) << 31)
314 
315 struct sbp2_command_orb {
316 	struct sbp2_orb base;
317 	struct {
318 		struct sbp2_pointer next;
319 		struct sbp2_pointer data_descriptor;
320 		__be32 misc;
321 		u8 command_block[SBP2_MAX_CDB_SIZE];
322 	} request;
323 	struct scsi_cmnd *cmd;
324 	scsi_done_fn_t done;
325 	struct sbp2_logical_unit *lu;
326 
327 	struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
328 	dma_addr_t page_table_bus;
329 };
330 
331 #define SBP2_ROM_VALUE_WILDCARD ~0         /* match all */
332 #define SBP2_ROM_VALUE_MISSING  0xff000000 /* not present in the unit dir. */
333 
334 /*
335  * List of devices with known bugs.
336  *
337  * The firmware_revision field, masked with 0xffff00, is the best
338  * indicator for the type of bridge chip of a device.  It yields a few
339  * false positives but this did not break correctly behaving devices
340  * so far.
341  */
342 static const struct {
343 	u32 firmware_revision;
344 	u32 model;
345 	unsigned int workarounds;
346 } sbp2_workarounds_table[] = {
347 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
348 		.firmware_revision	= 0x002800,
349 		.model			= 0x001010,
350 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
351 					  SBP2_WORKAROUND_MODE_SENSE_8 |
352 					  SBP2_WORKAROUND_POWER_CONDITION,
353 	},
354 	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
355 		.firmware_revision	= 0x002800,
356 		.model			= 0x000000,
357 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
358 	},
359 	/* Initio bridges, actually only needed for some older ones */ {
360 		.firmware_revision	= 0x000200,
361 		.model			= SBP2_ROM_VALUE_WILDCARD,
362 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36,
363 	},
364 	/* PL-3507 bridge with Prolific firmware */ {
365 		.firmware_revision	= 0x012800,
366 		.model			= SBP2_ROM_VALUE_WILDCARD,
367 		.workarounds		= SBP2_WORKAROUND_POWER_CONDITION,
368 	},
369 	/* Symbios bridge */ {
370 		.firmware_revision	= 0xa0b800,
371 		.model			= SBP2_ROM_VALUE_WILDCARD,
372 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
373 	},
374 	/* Datafab MD2-FW2 with Symbios/LSILogic SYM13FW500 bridge */ {
375 		.firmware_revision	= 0x002600,
376 		.model			= SBP2_ROM_VALUE_WILDCARD,
377 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS,
378 	},
379 	/*
380 	 * iPod 2nd generation: needs 128k max transfer size workaround
381 	 * iPod 3rd generation: needs fix capacity workaround
382 	 */
383 	{
384 		.firmware_revision	= 0x0a2700,
385 		.model			= 0x000000,
386 		.workarounds		= SBP2_WORKAROUND_128K_MAX_TRANS |
387 					  SBP2_WORKAROUND_FIX_CAPACITY,
388 	},
389 	/* iPod 4th generation */ {
390 		.firmware_revision	= 0x0a2700,
391 		.model			= 0x000021,
392 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
393 	},
394 	/* iPod mini */ {
395 		.firmware_revision	= 0x0a2700,
396 		.model			= 0x000022,
397 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
398 	},
399 	/* iPod mini */ {
400 		.firmware_revision	= 0x0a2700,
401 		.model			= 0x000023,
402 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
403 	},
404 	/* iPod Photo */ {
405 		.firmware_revision	= 0x0a2700,
406 		.model			= 0x00007e,
407 		.workarounds		= SBP2_WORKAROUND_FIX_CAPACITY,
408 	}
409 };
410 
411 static void free_orb(struct kref *kref)
412 {
413 	struct sbp2_orb *orb = container_of(kref, struct sbp2_orb, kref);
414 
415 	kfree(orb);
416 }
417 
418 static void sbp2_status_write(struct fw_card *card, struct fw_request *request,
419 			      int tcode, int destination, int source,
420 			      int generation, int speed,
421 			      unsigned long long offset,
422 			      void *payload, size_t length, void *callback_data)
423 {
424 	struct sbp2_logical_unit *lu = callback_data;
425 	struct sbp2_orb *orb;
426 	struct sbp2_status status;
427 	unsigned long flags;
428 
429 	if (tcode != TCODE_WRITE_BLOCK_REQUEST ||
430 	    length < 8 || length > sizeof(status)) {
431 		fw_send_response(card, request, RCODE_TYPE_ERROR);
432 		return;
433 	}
434 
435 	status.status  = be32_to_cpup(payload);
436 	status.orb_low = be32_to_cpup(payload + 4);
437 	memset(status.data, 0, sizeof(status.data));
438 	if (length > 8)
439 		memcpy(status.data, payload + 8, length - 8);
440 
441 	if (STATUS_GET_SOURCE(status) == 2 || STATUS_GET_SOURCE(status) == 3) {
442 		fw_notify("non-orb related status write, not handled\n");
443 		fw_send_response(card, request, RCODE_COMPLETE);
444 		return;
445 	}
446 
447 	/* Lookup the orb corresponding to this status write. */
448 	spin_lock_irqsave(&card->lock, flags);
449 	list_for_each_entry(orb, &lu->orb_list, link) {
450 		if (STATUS_GET_ORB_HIGH(status) == 0 &&
451 		    STATUS_GET_ORB_LOW(status) == orb->request_bus) {
452 			orb->rcode = RCODE_COMPLETE;
453 			list_del(&orb->link);
454 			break;
455 		}
456 	}
457 	spin_unlock_irqrestore(&card->lock, flags);
458 
459 	if (&orb->link != &lu->orb_list) {
460 		orb->callback(orb, &status);
461 		kref_put(&orb->kref, free_orb);
462 	} else {
463 		fw_error("status write for unknown orb\n");
464 	}
465 
466 	fw_send_response(card, request, RCODE_COMPLETE);
467 }
468 
469 static void complete_transaction(struct fw_card *card, int rcode,
470 				 void *payload, size_t length, void *data)
471 {
472 	struct sbp2_orb *orb = data;
473 	unsigned long flags;
474 
475 	/*
476 	 * This is a little tricky.  We can get the status write for
477 	 * the orb before we get this callback.  The status write
478 	 * handler above will assume the orb pointer transaction was
479 	 * successful and set the rcode to RCODE_COMPLETE for the orb.
480 	 * So this callback only sets the rcode if it hasn't already
481 	 * been set and only does the cleanup if the transaction
482 	 * failed and we didn't already get a status write.
483 	 */
484 	spin_lock_irqsave(&card->lock, flags);
485 
486 	if (orb->rcode == -1)
487 		orb->rcode = rcode;
488 	if (orb->rcode != RCODE_COMPLETE) {
489 		list_del(&orb->link);
490 		spin_unlock_irqrestore(&card->lock, flags);
491 		orb->callback(orb, NULL);
492 	} else {
493 		spin_unlock_irqrestore(&card->lock, flags);
494 	}
495 
496 	kref_put(&orb->kref, free_orb);
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 	/* Take a ref for the orb list and for the transaction callback. */
513 	kref_get(&orb->kref);
514 	kref_get(&orb->kref);
515 
516 	fw_send_request(device->card, &orb->t, TCODE_WRITE_BLOCK_REQUEST,
517 			node_id, generation, device->max_speed, offset,
518 			&orb->pointer, sizeof(orb->pointer),
519 			complete_transaction, orb);
520 }
521 
522 static int sbp2_cancel_orbs(struct sbp2_logical_unit *lu)
523 {
524 	struct fw_device *device = target_device(lu->tgt);
525 	struct sbp2_orb *orb, *next;
526 	struct list_head list;
527 	unsigned long flags;
528 	int retval = -ENOENT;
529 
530 	INIT_LIST_HEAD(&list);
531 	spin_lock_irqsave(&device->card->lock, flags);
532 	list_splice_init(&lu->orb_list, &list);
533 	spin_unlock_irqrestore(&device->card->lock, flags);
534 
535 	list_for_each_entry_safe(orb, next, &list, link) {
536 		retval = 0;
537 		if (fw_cancel_transaction(device->card, &orb->t) == 0)
538 			continue;
539 
540 		orb->rcode = RCODE_CANCELLED;
541 		orb->callback(orb, NULL);
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_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_ATOMIC);
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 		fw_error("%s: orb reply timed out, rcode=0x%02x\n",
623 			 lu->tgt->bus_id, orb->base.rcode);
624 		goto out;
625 	}
626 
627 	if (orb->base.rcode != RCODE_COMPLETE) {
628 		fw_error("%s: management write failed, rcode 0x%02x\n",
629 			 lu->tgt->bus_id, 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 		fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
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_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, sizeof(d));
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_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, sizeof(d), 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_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_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_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 static void sbp2_release_target(struct kref *kref)
787 {
788 	struct sbp2_target *tgt = container_of(kref, struct sbp2_target, kref);
789 	struct sbp2_logical_unit *lu, *next;
790 	struct Scsi_Host *shost =
791 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
792 	struct scsi_device *sdev;
793 	struct fw_device *device = target_device(tgt);
794 
795 	/* prevent deadlocks */
796 	sbp2_unblock(tgt);
797 
798 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
799 		sdev = scsi_device_lookup(shost, 0, 0, sbp2_lun2int(lu->lun));
800 		if (sdev) {
801 			scsi_remove_device(sdev);
802 			scsi_device_put(sdev);
803 		}
804 		if (lu->login_id != INVALID_LOGIN_ID) {
805 			int generation, node_id;
806 			/*
807 			 * tgt->node_id may be obsolete here if we failed
808 			 * during initial login or after a bus reset where
809 			 * the topology changed.
810 			 */
811 			generation = device->generation;
812 			smp_rmb(); /* node_id vs. generation */
813 			node_id    = device->node_id;
814 			sbp2_send_management_orb(lu, node_id, generation,
815 						 SBP2_LOGOUT_REQUEST,
816 						 lu->login_id, NULL);
817 		}
818 		fw_core_remove_address_handler(&lu->address_handler);
819 		list_del(&lu->link);
820 		kfree(lu);
821 	}
822 	scsi_remove_host(shost);
823 	fw_notify("released %s, target %d:0:0\n", tgt->bus_id, shost->host_no);
824 
825 	fw_unit_put(tgt->unit);
826 	scsi_host_put(shost);
827 	fw_device_put(device);
828 }
829 
830 static struct workqueue_struct *sbp2_wq;
831 
832 static void sbp2_target_put(struct sbp2_target *tgt)
833 {
834 	kref_put(&tgt->kref, sbp2_release_target);
835 }
836 
837 /*
838  * Always get the target's kref when scheduling work on one its units.
839  * Each workqueue job is responsible to call sbp2_target_put() upon return.
840  */
841 static void sbp2_queue_work(struct sbp2_logical_unit *lu, unsigned long delay)
842 {
843 	kref_get(&lu->tgt->kref);
844 	if (!queue_delayed_work(sbp2_wq, &lu->work, delay))
845 		sbp2_target_put(lu->tgt);
846 }
847 
848 /*
849  * Write retransmit retry values into the BUSY_TIMEOUT register.
850  * - The single-phase retry protocol is supported by all SBP-2 devices, but the
851  *   default retry_limit value is 0 (i.e. never retry transmission). We write a
852  *   saner value after logging into the device.
853  * - The dual-phase retry protocol is optional to implement, and if not
854  *   supported, writes to the dual-phase portion of the register will be
855  *   ignored. We try to write the original 1394-1995 default here.
856  * - In the case of devices that are also SBP-3-compliant, all writes are
857  *   ignored, as the register is read-only, but contains single-phase retry of
858  *   15, which is what we're trying to set for all SBP-2 device anyway, so this
859  *   write attempt is safe and yields more consistent behavior for all devices.
860  *
861  * See section 8.3.2.3.5 of the 1394-1995 spec, section 6.2 of the SBP-2 spec,
862  * and section 6.4 of the SBP-3 spec for further details.
863  */
864 static void sbp2_set_busy_timeout(struct sbp2_logical_unit *lu)
865 {
866 	struct fw_device *device = target_device(lu->tgt);
867 	__be32 d = cpu_to_be32(SBP2_CYCLE_LIMIT | SBP2_RETRY_LIMIT);
868 
869 	fw_run_transaction(device->card, TCODE_WRITE_QUADLET_REQUEST,
870 			   lu->tgt->node_id, lu->generation, device->max_speed,
871 			   CSR_REGISTER_BASE + CSR_BUSY_TIMEOUT,
872 			   &d, sizeof(d));
873 }
874 
875 static void sbp2_reconnect(struct work_struct *work);
876 
877 static void sbp2_login(struct work_struct *work)
878 {
879 	struct sbp2_logical_unit *lu =
880 		container_of(work, struct sbp2_logical_unit, work.work);
881 	struct sbp2_target *tgt = lu->tgt;
882 	struct fw_device *device = target_device(tgt);
883 	struct Scsi_Host *shost;
884 	struct scsi_device *sdev;
885 	struct sbp2_login_response response;
886 	int generation, node_id, local_node_id;
887 
888 	if (fw_device_is_shutdown(device))
889 		goto out;
890 
891 	generation    = device->generation;
892 	smp_rmb();    /* node IDs must not be older than generation */
893 	node_id       = device->node_id;
894 	local_node_id = device->card->node_id;
895 
896 	/* If this is a re-login attempt, log out, or we might be rejected. */
897 	if (lu->has_sdev)
898 		sbp2_send_management_orb(lu, device->node_id, generation,
899 				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
900 
901 	if (sbp2_send_management_orb(lu, node_id, generation,
902 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
903 		if (lu->retries++ < 5) {
904 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
905 		} else {
906 			fw_error("%s: failed to login to LUN %04x\n",
907 				 tgt->bus_id, lu->lun);
908 			/* Let any waiting I/O fail from now on. */
909 			sbp2_unblock(lu->tgt);
910 		}
911 		goto out;
912 	}
913 
914 	tgt->node_id	  = node_id;
915 	tgt->address_high = local_node_id << 16;
916 	smp_wmb();	  /* node IDs must not be older than generation */
917 	lu->generation	  = generation;
918 
919 	lu->command_block_agent_address =
920 		((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
921 		      << 32) | be32_to_cpu(response.command_block_agent.low);
922 	lu->login_id = be32_to_cpu(response.misc) & 0xffff;
923 
924 	fw_notify("%s: logged in to LUN %04x (%d retries)\n",
925 		  tgt->bus_id, lu->lun, lu->retries);
926 
927 	/* set appropriate retry limit(s) in BUSY_TIMEOUT register */
928 	sbp2_set_busy_timeout(lu);
929 
930 	PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
931 	sbp2_agent_reset(lu);
932 
933 	/* This was a re-login. */
934 	if (lu->has_sdev) {
935 		sbp2_cancel_orbs(lu);
936 		sbp2_conditionally_unblock(lu);
937 		goto out;
938 	}
939 
940 	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
941 		ssleep(SBP2_INQUIRY_DELAY);
942 
943 	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
944 	sdev = __scsi_add_device(shost, 0, 0, sbp2_lun2int(lu->lun), lu);
945 	/*
946 	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
947 	 * Therefore __scsi_add_device() will get into trouble if a bus reset
948 	 * happens in parallel.  It will either fail or leave us with an
949 	 * unusable sdev.  As a workaround we check for this and retry the
950 	 * whole login and SCSI probing.
951 	 */
952 
953 	/* Reported error during __scsi_add_device() */
954 	if (IS_ERR(sdev))
955 		goto out_logout_login;
956 
957 	/* Unreported error during __scsi_add_device() */
958 	smp_rmb(); /* get current card generation */
959 	if (generation != device->card->generation) {
960 		scsi_remove_device(sdev);
961 		scsi_device_put(sdev);
962 		goto out_logout_login;
963 	}
964 
965 	/* No error during __scsi_add_device() */
966 	lu->has_sdev = true;
967 	scsi_device_put(sdev);
968 	sbp2_allow_block(lu);
969 	goto out;
970 
971  out_logout_login:
972 	smp_rmb(); /* generation may have changed */
973 	generation = device->generation;
974 	smp_rmb(); /* node_id must not be older than generation */
975 
976 	sbp2_send_management_orb(lu, device->node_id, generation,
977 				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
978 	/*
979 	 * If a bus reset happened, sbp2_update will have requeued
980 	 * lu->work already.  Reset the work from reconnect to login.
981 	 */
982 	PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
983  out:
984 	sbp2_target_put(tgt);
985 }
986 
987 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
988 {
989 	struct sbp2_logical_unit *lu;
990 
991 	lu = kmalloc(sizeof(*lu), GFP_KERNEL);
992 	if (!lu)
993 		return -ENOMEM;
994 
995 	lu->address_handler.length           = 0x100;
996 	lu->address_handler.address_callback = sbp2_status_write;
997 	lu->address_handler.callback_data    = lu;
998 
999 	if (fw_core_add_address_handler(&lu->address_handler,
1000 					&fw_high_memory_region) < 0) {
1001 		kfree(lu);
1002 		return -ENOMEM;
1003 	}
1004 
1005 	lu->tgt      = tgt;
1006 	lu->lun      = lun_entry & 0xffff;
1007 	lu->login_id = INVALID_LOGIN_ID;
1008 	lu->retries  = 0;
1009 	lu->has_sdev = false;
1010 	lu->blocked  = false;
1011 	++tgt->dont_block;
1012 	INIT_LIST_HEAD(&lu->orb_list);
1013 	INIT_DELAYED_WORK(&lu->work, sbp2_login);
1014 
1015 	list_add_tail(&lu->link, &tgt->lu_list);
1016 	return 0;
1017 }
1018 
1019 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
1020 {
1021 	struct fw_csr_iterator ci;
1022 	int key, value;
1023 
1024 	fw_csr_iterator_init(&ci, directory);
1025 	while (fw_csr_iterator_next(&ci, &key, &value))
1026 		if (key == SBP2_CSR_LOGICAL_UNIT_NUMBER &&
1027 		    sbp2_add_logical_unit(tgt, value) < 0)
1028 			return -ENOMEM;
1029 	return 0;
1030 }
1031 
1032 static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
1033 			      u32 *model, u32 *firmware_revision)
1034 {
1035 	struct fw_csr_iterator ci;
1036 	int key, value;
1037 	unsigned int timeout;
1038 
1039 	fw_csr_iterator_init(&ci, directory);
1040 	while (fw_csr_iterator_next(&ci, &key, &value)) {
1041 		switch (key) {
1042 
1043 		case CSR_DEPENDENT_INFO | CSR_OFFSET:
1044 			tgt->management_agent_address =
1045 					CSR_REGISTER_BASE + 4 * value;
1046 			break;
1047 
1048 		case CSR_DIRECTORY_ID:
1049 			tgt->directory_id = value;
1050 			break;
1051 
1052 		case CSR_MODEL:
1053 			*model = value;
1054 			break;
1055 
1056 		case SBP2_CSR_FIRMWARE_REVISION:
1057 			*firmware_revision = value;
1058 			break;
1059 
1060 		case SBP2_CSR_UNIT_CHARACTERISTICS:
1061 			/* the timeout value is stored in 500ms units */
1062 			timeout = ((unsigned int) value >> 8 & 0xff) * 500;
1063 			timeout = max(timeout, SBP2_MIN_LOGIN_ORB_TIMEOUT);
1064 			tgt->mgt_orb_timeout =
1065 				  min(timeout, SBP2_MAX_LOGIN_ORB_TIMEOUT);
1066 
1067 			if (timeout > tgt->mgt_orb_timeout)
1068 				fw_notify("%s: config rom contains %ds "
1069 					  "management ORB timeout, limiting "
1070 					  "to %ds\n", tgt->bus_id,
1071 					  timeout / 1000,
1072 					  tgt->mgt_orb_timeout / 1000);
1073 			break;
1074 
1075 		case SBP2_CSR_LOGICAL_UNIT_NUMBER:
1076 			if (sbp2_add_logical_unit(tgt, value) < 0)
1077 				return -ENOMEM;
1078 			break;
1079 
1080 		case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
1081 			/* Adjust for the increment in the iterator */
1082 			if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)
1083 				return -ENOMEM;
1084 			break;
1085 		}
1086 	}
1087 	return 0;
1088 }
1089 
1090 static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
1091 				  u32 firmware_revision)
1092 {
1093 	int i;
1094 	unsigned int w = sbp2_param_workarounds;
1095 
1096 	if (w)
1097 		fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
1098 			  "if you need the workarounds parameter for %s\n",
1099 			  tgt->bus_id);
1100 
1101 	if (w & SBP2_WORKAROUND_OVERRIDE)
1102 		goto out;
1103 
1104 	for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
1105 
1106 		if (sbp2_workarounds_table[i].firmware_revision !=
1107 		    (firmware_revision & 0xffffff00))
1108 			continue;
1109 
1110 		if (sbp2_workarounds_table[i].model != model &&
1111 		    sbp2_workarounds_table[i].model != SBP2_ROM_VALUE_WILDCARD)
1112 			continue;
1113 
1114 		w |= sbp2_workarounds_table[i].workarounds;
1115 		break;
1116 	}
1117  out:
1118 	if (w)
1119 		fw_notify("Workarounds for %s: 0x%x "
1120 			  "(firmware_revision 0x%06x, model_id 0x%06x)\n",
1121 			  tgt->bus_id, w, firmware_revision, model);
1122 	tgt->workarounds = w;
1123 }
1124 
1125 static struct scsi_host_template scsi_driver_template;
1126 
1127 static int sbp2_probe(struct device *dev)
1128 {
1129 	struct fw_unit *unit = fw_unit(dev);
1130 	struct fw_device *device = fw_parent_device(unit);
1131 	struct sbp2_target *tgt;
1132 	struct sbp2_logical_unit *lu;
1133 	struct Scsi_Host *shost;
1134 	u32 model, firmware_revision;
1135 
1136 	if (dma_get_max_seg_size(device->card->device) > SBP2_MAX_SEG_SIZE)
1137 		BUG_ON(dma_set_max_seg_size(device->card->device,
1138 					    SBP2_MAX_SEG_SIZE));
1139 
1140 	shost = scsi_host_alloc(&scsi_driver_template, sizeof(*tgt));
1141 	if (shost == NULL)
1142 		return -ENOMEM;
1143 
1144 	tgt = (struct sbp2_target *)shost->hostdata;
1145 	dev_set_drvdata(&unit->device, tgt);
1146 	tgt->unit = unit;
1147 	kref_init(&tgt->kref);
1148 	INIT_LIST_HEAD(&tgt->lu_list);
1149 	tgt->bus_id = dev_name(&unit->device);
1150 	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];
1151 
1152 	if (fw_device_enable_phys_dma(device) < 0)
1153 		goto fail_shost_put;
1154 
1155 	shost->max_cmd_len = SBP2_MAX_CDB_SIZE;
1156 
1157 	if (scsi_add_host(shost, &unit->device) < 0)
1158 		goto fail_shost_put;
1159 
1160 	fw_device_get(device);
1161 	fw_unit_get(unit);
1162 
1163 	/* implicit directory ID */
1164 	tgt->directory_id = ((unit->directory - device->config_rom) * 4
1165 			     + CSR_CONFIG_ROM) & 0xffffff;
1166 
1167 	firmware_revision = SBP2_ROM_VALUE_MISSING;
1168 	model		  = SBP2_ROM_VALUE_MISSING;
1169 
1170 	if (sbp2_scan_unit_dir(tgt, unit->directory, &model,
1171 			       &firmware_revision) < 0)
1172 		goto fail_tgt_put;
1173 
1174 	sbp2_init_workarounds(tgt, model, firmware_revision);
1175 
1176 	/*
1177 	 * At S100 we can do 512 bytes per packet, at S200 1024 bytes,
1178 	 * and so on up to 4096 bytes.  The SBP-2 max_payload field
1179 	 * specifies the max payload size as 2 ^ (max_payload + 2), so
1180 	 * if we set this to max_speed + 7, we get the right value.
1181 	 */
1182 	tgt->max_payload = min(device->max_speed + 7, 10U);
1183 	tgt->max_payload = min(tgt->max_payload, device->card->max_receive - 1);
1184 
1185 	/* Do the login in a workqueue so we can easily reschedule retries. */
1186 	list_for_each_entry(lu, &tgt->lu_list, link)
1187 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1188 	return 0;
1189 
1190  fail_tgt_put:
1191 	sbp2_target_put(tgt);
1192 	return -ENOMEM;
1193 
1194  fail_shost_put:
1195 	scsi_host_put(shost);
1196 	return -ENOMEM;
1197 }
1198 
1199 static int sbp2_remove(struct device *dev)
1200 {
1201 	struct fw_unit *unit = fw_unit(dev);
1202 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1203 
1204 	sbp2_target_put(tgt);
1205 	return 0;
1206 }
1207 
1208 static void sbp2_reconnect(struct work_struct *work)
1209 {
1210 	struct sbp2_logical_unit *lu =
1211 		container_of(work, struct sbp2_logical_unit, work.work);
1212 	struct sbp2_target *tgt = lu->tgt;
1213 	struct fw_device *device = target_device(tgt);
1214 	int generation, node_id, local_node_id;
1215 
1216 	if (fw_device_is_shutdown(device))
1217 		goto out;
1218 
1219 	generation    = device->generation;
1220 	smp_rmb();    /* node IDs must not be older than generation */
1221 	node_id       = device->node_id;
1222 	local_node_id = device->card->node_id;
1223 
1224 	if (sbp2_send_management_orb(lu, node_id, generation,
1225 				     SBP2_RECONNECT_REQUEST,
1226 				     lu->login_id, NULL) < 0) {
1227 		/*
1228 		 * If reconnect was impossible even though we are in the
1229 		 * current generation, fall back and try to log in again.
1230 		 *
1231 		 * We could check for "Function rejected" status, but
1232 		 * looking at the bus generation as simpler and more general.
1233 		 */
1234 		smp_rmb(); /* get current card generation */
1235 		if (generation == device->card->generation ||
1236 		    lu->retries++ >= 5) {
1237 			fw_error("%s: failed to reconnect\n", tgt->bus_id);
1238 			lu->retries = 0;
1239 			PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
1240 		}
1241 		sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
1242 		goto out;
1243 	}
1244 
1245 	tgt->node_id      = node_id;
1246 	tgt->address_high = local_node_id << 16;
1247 	smp_wmb();	  /* node IDs must not be older than generation */
1248 	lu->generation	  = generation;
1249 
1250 	fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
1251 		  tgt->bus_id, lu->lun, lu->retries);
1252 
1253 	sbp2_agent_reset(lu);
1254 	sbp2_cancel_orbs(lu);
1255 	sbp2_conditionally_unblock(lu);
1256  out:
1257 	sbp2_target_put(tgt);
1258 }
1259 
1260 static void sbp2_update(struct fw_unit *unit)
1261 {
1262 	struct sbp2_target *tgt = dev_get_drvdata(&unit->device);
1263 	struct sbp2_logical_unit *lu;
1264 
1265 	fw_device_enable_phys_dma(fw_parent_device(unit));
1266 
1267 	/*
1268 	 * Fw-core serializes sbp2_update() against sbp2_remove().
1269 	 * Iteration over tgt->lu_list is therefore safe here.
1270 	 */
1271 	list_for_each_entry(lu, &tgt->lu_list, link) {
1272 		sbp2_conditionally_block(lu);
1273 		lu->retries = 0;
1274 		sbp2_queue_work(lu, 0);
1275 	}
1276 }
1277 
1278 #define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
1279 #define SBP2_SW_VERSION_ENTRY	0x00010483
1280 
1281 static const struct ieee1394_device_id sbp2_id_table[] = {
1282 	{
1283 		.match_flags  = IEEE1394_MATCH_SPECIFIER_ID |
1284 				IEEE1394_MATCH_VERSION,
1285 		.specifier_id = SBP2_UNIT_SPEC_ID_ENTRY,
1286 		.version      = SBP2_SW_VERSION_ENTRY,
1287 	},
1288 	{ }
1289 };
1290 
1291 static struct fw_driver sbp2_driver = {
1292 	.driver   = {
1293 		.owner  = THIS_MODULE,
1294 		.name   = sbp2_driver_name,
1295 		.bus    = &fw_bus_type,
1296 		.probe  = sbp2_probe,
1297 		.remove = sbp2_remove,
1298 	},
1299 	.update   = sbp2_update,
1300 	.id_table = sbp2_id_table,
1301 };
1302 
1303 static void sbp2_unmap_scatterlist(struct device *card_device,
1304 				   struct sbp2_command_orb *orb)
1305 {
1306 	if (scsi_sg_count(orb->cmd))
1307 		dma_unmap_sg(card_device, scsi_sglist(orb->cmd),
1308 			     scsi_sg_count(orb->cmd),
1309 			     orb->cmd->sc_data_direction);
1310 
1311 	if (orb->request.misc & cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT))
1312 		dma_unmap_single(card_device, orb->page_table_bus,
1313 				 sizeof(orb->page_table), DMA_TO_DEVICE);
1314 }
1315 
1316 static unsigned int sbp2_status_to_sense_data(u8 *sbp2_status, u8 *sense_data)
1317 {
1318 	int sam_status;
1319 
1320 	sense_data[0] = 0x70;
1321 	sense_data[1] = 0x0;
1322 	sense_data[2] = sbp2_status[1];
1323 	sense_data[3] = sbp2_status[4];
1324 	sense_data[4] = sbp2_status[5];
1325 	sense_data[5] = sbp2_status[6];
1326 	sense_data[6] = sbp2_status[7];
1327 	sense_data[7] = 10;
1328 	sense_data[8] = sbp2_status[8];
1329 	sense_data[9] = sbp2_status[9];
1330 	sense_data[10] = sbp2_status[10];
1331 	sense_data[11] = sbp2_status[11];
1332 	sense_data[12] = sbp2_status[2];
1333 	sense_data[13] = sbp2_status[3];
1334 	sense_data[14] = sbp2_status[12];
1335 	sense_data[15] = sbp2_status[13];
1336 
1337 	sam_status = sbp2_status[0] & 0x3f;
1338 
1339 	switch (sam_status) {
1340 	case SAM_STAT_GOOD:
1341 	case SAM_STAT_CHECK_CONDITION:
1342 	case SAM_STAT_CONDITION_MET:
1343 	case SAM_STAT_BUSY:
1344 	case SAM_STAT_RESERVATION_CONFLICT:
1345 	case SAM_STAT_COMMAND_TERMINATED:
1346 		return DID_OK << 16 | sam_status;
1347 
1348 	default:
1349 		return DID_ERROR << 16;
1350 	}
1351 }
1352 
1353 static void complete_command_orb(struct sbp2_orb *base_orb,
1354 				 struct sbp2_status *status)
1355 {
1356 	struct sbp2_command_orb *orb =
1357 		container_of(base_orb, struct sbp2_command_orb, base);
1358 	struct fw_device *device = target_device(orb->lu->tgt);
1359 	int result;
1360 
1361 	if (status != NULL) {
1362 		if (STATUS_GET_DEAD(*status))
1363 			sbp2_agent_reset_no_wait(orb->lu);
1364 
1365 		switch (STATUS_GET_RESPONSE(*status)) {
1366 		case SBP2_STATUS_REQUEST_COMPLETE:
1367 			result = DID_OK << 16;
1368 			break;
1369 		case SBP2_STATUS_TRANSPORT_FAILURE:
1370 			result = DID_BUS_BUSY << 16;
1371 			break;
1372 		case SBP2_STATUS_ILLEGAL_REQUEST:
1373 		case SBP2_STATUS_VENDOR_DEPENDENT:
1374 		default:
1375 			result = DID_ERROR << 16;
1376 			break;
1377 		}
1378 
1379 		if (result == DID_OK << 16 && STATUS_GET_LEN(*status) > 1)
1380 			result = sbp2_status_to_sense_data(STATUS_GET_DATA(*status),
1381 							   orb->cmd->sense_buffer);
1382 	} else {
1383 		/*
1384 		 * If the orb completes with status == NULL, something
1385 		 * went wrong, typically a bus reset happened mid-orb
1386 		 * or when sending the write (less likely).
1387 		 */
1388 		result = DID_BUS_BUSY << 16;
1389 		sbp2_conditionally_block(orb->lu);
1390 	}
1391 
1392 	dma_unmap_single(device->card->device, orb->base.request_bus,
1393 			 sizeof(orb->request), DMA_TO_DEVICE);
1394 	sbp2_unmap_scatterlist(device->card->device, orb);
1395 
1396 	orb->cmd->result = result;
1397 	orb->done(orb->cmd);
1398 }
1399 
1400 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
1401 		struct fw_device *device, struct sbp2_logical_unit *lu)
1402 {
1403 	struct scatterlist *sg = scsi_sglist(orb->cmd);
1404 	int i, n;
1405 
1406 	n = dma_map_sg(device->card->device, sg, scsi_sg_count(orb->cmd),
1407 		       orb->cmd->sc_data_direction);
1408 	if (n == 0)
1409 		goto fail;
1410 
1411 	/*
1412 	 * Handle the special case where there is only one element in
1413 	 * the scatter list by converting it to an immediate block
1414 	 * request. This is also a workaround for broken devices such
1415 	 * as the second generation iPod which doesn't support page
1416 	 * tables.
1417 	 */
1418 	if (n == 1) {
1419 		orb->request.data_descriptor.high =
1420 			cpu_to_be32(lu->tgt->address_high);
1421 		orb->request.data_descriptor.low  =
1422 			cpu_to_be32(sg_dma_address(sg));
1423 		orb->request.misc |=
1424 			cpu_to_be32(COMMAND_ORB_DATA_SIZE(sg_dma_len(sg)));
1425 		return 0;
1426 	}
1427 
1428 	for_each_sg(sg, sg, n, i) {
1429 		orb->page_table[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
1430 		orb->page_table[i].low = cpu_to_be32(sg_dma_address(sg));
1431 	}
1432 
1433 	orb->page_table_bus =
1434 		dma_map_single(device->card->device, orb->page_table,
1435 			       sizeof(orb->page_table), DMA_TO_DEVICE);
1436 	if (dma_mapping_error(device->card->device, orb->page_table_bus))
1437 		goto fail_page_table;
1438 
1439 	/*
1440 	 * The data_descriptor pointer is the one case where we need
1441 	 * to fill in the node ID part of the address.  All other
1442 	 * pointers assume that the data referenced reside on the
1443 	 * initiator (i.e. us), but data_descriptor can refer to data
1444 	 * on other nodes so we need to put our ID in descriptor.high.
1445 	 */
1446 	orb->request.data_descriptor.high = cpu_to_be32(lu->tgt->address_high);
1447 	orb->request.data_descriptor.low  = cpu_to_be32(orb->page_table_bus);
1448 	orb->request.misc |= cpu_to_be32(COMMAND_ORB_PAGE_TABLE_PRESENT |
1449 					 COMMAND_ORB_DATA_SIZE(n));
1450 
1451 	return 0;
1452 
1453  fail_page_table:
1454 	dma_unmap_sg(device->card->device, scsi_sglist(orb->cmd),
1455 		     scsi_sg_count(orb->cmd), orb->cmd->sc_data_direction);
1456  fail:
1457 	return -ENOMEM;
1458 }
1459 
1460 /* SCSI stack integration */
1461 
1462 static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
1463 {
1464 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1465 	struct fw_device *device = target_device(lu->tgt);
1466 	struct sbp2_command_orb *orb;
1467 	int generation, retval = SCSI_MLQUEUE_HOST_BUSY;
1468 
1469 	/*
1470 	 * Bidirectional commands are not yet implemented, and unknown
1471 	 * transfer direction not handled.
1472 	 */
1473 	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
1474 		fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
1475 		cmd->result = DID_ERROR << 16;
1476 		done(cmd);
1477 		return 0;
1478 	}
1479 
1480 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
1481 	if (orb == NULL) {
1482 		fw_notify("failed to alloc orb\n");
1483 		return SCSI_MLQUEUE_HOST_BUSY;
1484 	}
1485 
1486 	/* Initialize rcode to something not RCODE_COMPLETE. */
1487 	orb->base.rcode = -1;
1488 	kref_init(&orb->base.kref);
1489 
1490 	orb->lu   = lu;
1491 	orb->done = done;
1492 	orb->cmd  = cmd;
1493 
1494 	orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
1495 	orb->request.misc = cpu_to_be32(
1496 		COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
1497 		COMMAND_ORB_SPEED(device->max_speed) |
1498 		COMMAND_ORB_NOTIFY);
1499 
1500 	if (cmd->sc_data_direction == DMA_FROM_DEVICE)
1501 		orb->request.misc |= cpu_to_be32(COMMAND_ORB_DIRECTION);
1502 
1503 	generation = device->generation;
1504 	smp_rmb();    /* sbp2_map_scatterlist looks at tgt->address_high */
1505 
1506 	if (scsi_sg_count(cmd) && sbp2_map_scatterlist(orb, device, lu) < 0)
1507 		goto out;
1508 
1509 	memcpy(orb->request.command_block, cmd->cmnd, cmd->cmd_len);
1510 
1511 	orb->base.callback = complete_command_orb;
1512 	orb->base.request_bus =
1513 		dma_map_single(device->card->device, &orb->request,
1514 			       sizeof(orb->request), DMA_TO_DEVICE);
1515 	if (dma_mapping_error(device->card->device, orb->base.request_bus)) {
1516 		sbp2_unmap_scatterlist(device->card->device, orb);
1517 		goto out;
1518 	}
1519 
1520 	sbp2_send_orb(&orb->base, lu, lu->tgt->node_id, generation,
1521 		      lu->command_block_agent_address + SBP2_ORB_POINTER);
1522 	retval = 0;
1523  out:
1524 	kref_put(&orb->base.kref, free_orb);
1525 	return retval;
1526 }
1527 
1528 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
1529 {
1530 	struct sbp2_logical_unit *lu = sdev->hostdata;
1531 
1532 	/* (Re-)Adding logical units via the SCSI stack is not supported. */
1533 	if (!lu)
1534 		return -ENOSYS;
1535 
1536 	sdev->allow_restart = 1;
1537 
1538 	/* SBP-2 requires quadlet alignment of the data buffers. */
1539 	blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
1540 
1541 	if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
1542 		sdev->inquiry_len = 36;
1543 
1544 	return 0;
1545 }
1546 
1547 static int sbp2_scsi_slave_configure(struct scsi_device *sdev)
1548 {
1549 	struct sbp2_logical_unit *lu = sdev->hostdata;
1550 
1551 	sdev->use_10_for_rw = 1;
1552 
1553 	if (sbp2_param_exclusive_login)
1554 		sdev->manage_start_stop = 1;
1555 
1556 	if (sdev->type == TYPE_ROM)
1557 		sdev->use_10_for_ms = 1;
1558 
1559 	if (sdev->type == TYPE_DISK &&
1560 	    lu->tgt->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
1561 		sdev->skip_ms_page_8 = 1;
1562 
1563 	if (lu->tgt->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
1564 		sdev->fix_capacity = 1;
1565 
1566 	if (lu->tgt->workarounds & SBP2_WORKAROUND_POWER_CONDITION)
1567 		sdev->start_stop_pwr_cond = 1;
1568 
1569 	if (lu->tgt->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
1570 		blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
1571 
1572 	blk_queue_max_segment_size(sdev->request_queue, SBP2_MAX_SEG_SIZE);
1573 
1574 	return 0;
1575 }
1576 
1577 /*
1578  * Called by scsi stack when something has really gone wrong.  Usually
1579  * called when a command has timed-out for some reason.
1580  */
1581 static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
1582 {
1583 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
1584 
1585 	fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
1586 	sbp2_agent_reset(lu);
1587 	sbp2_cancel_orbs(lu);
1588 
1589 	return SUCCESS;
1590 }
1591 
1592 /*
1593  * Format of /sys/bus/scsi/devices/.../ieee1394_id:
1594  * u64 EUI-64 : u24 directory_ID : u16 LUN  (all printed in hexadecimal)
1595  *
1596  * This is the concatenation of target port identifier and logical unit
1597  * identifier as per SAM-2...SAM-4 annex A.
1598  */
1599 static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
1600 			struct device_attribute *attr, char *buf)
1601 {
1602 	struct scsi_device *sdev = to_scsi_device(dev);
1603 	struct sbp2_logical_unit *lu;
1604 
1605 	if (!sdev)
1606 		return 0;
1607 
1608 	lu = sdev->hostdata;
1609 
1610 	return sprintf(buf, "%016llx:%06x:%04x\n",
1611 			(unsigned long long)lu->tgt->guid,
1612 			lu->tgt->directory_id, lu->lun);
1613 }
1614 
1615 static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);
1616 
1617 static struct device_attribute *sbp2_scsi_sysfs_attrs[] = {
1618 	&dev_attr_ieee1394_id,
1619 	NULL
1620 };
1621 
1622 static struct scsi_host_template scsi_driver_template = {
1623 	.module			= THIS_MODULE,
1624 	.name			= "SBP-2 IEEE-1394",
1625 	.proc_name		= sbp2_driver_name,
1626 	.queuecommand		= sbp2_scsi_queuecommand,
1627 	.slave_alloc		= sbp2_scsi_slave_alloc,
1628 	.slave_configure	= sbp2_scsi_slave_configure,
1629 	.eh_abort_handler	= sbp2_scsi_abort,
1630 	.this_id		= -1,
1631 	.sg_tablesize		= SG_ALL,
1632 	.use_clustering		= ENABLE_CLUSTERING,
1633 	.cmd_per_lun		= 1,
1634 	.can_queue		= 1,
1635 	.sdev_attrs		= sbp2_scsi_sysfs_attrs,
1636 };
1637 
1638 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
1639 MODULE_DESCRIPTION("SCSI over IEEE1394");
1640 MODULE_LICENSE("GPL");
1641 MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);
1642 
1643 /* Provide a module alias so root-on-sbp2 initrds don't break. */
1644 #ifndef CONFIG_IEEE1394_SBP2_MODULE
1645 MODULE_ALIAS("sbp2");
1646 #endif
1647 
1648 static int __init sbp2_init(void)
1649 {
1650 	sbp2_wq = create_singlethread_workqueue(KBUILD_MODNAME);
1651 	if (!sbp2_wq)
1652 		return -ENOMEM;
1653 
1654 	return driver_register(&sbp2_driver.driver);
1655 }
1656 
1657 static void __exit sbp2_cleanup(void)
1658 {
1659 	driver_unregister(&sbp2_driver.driver);
1660 	destroy_workqueue(sbp2_wq);
1661 }
1662 
1663 module_init(sbp2_init);
1664 module_exit(sbp2_cleanup);
1665