xref: /linux/drivers/scsi/esp_scsi.c (revision eb2bce7f5e7ac1ca6da434461217fadf3c688d2c)
1 /* esp_scsi.c: ESP SCSI driver.
2  *
3  * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/types.h>
8 #include <linux/slab.h>
9 #include <linux/delay.h>
10 #include <linux/list.h>
11 #include <linux/completion.h>
12 #include <linux/kallsyms.h>
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/init.h>
16 #include <linux/irqreturn.h>
17 
18 #include <asm/irq.h>
19 #include <asm/io.h>
20 #include <asm/dma.h>
21 
22 #include <scsi/scsi.h>
23 #include <scsi/scsi_host.h>
24 #include <scsi/scsi_cmnd.h>
25 #include <scsi/scsi_device.h>
26 #include <scsi/scsi_tcq.h>
27 #include <scsi/scsi_dbg.h>
28 #include <scsi/scsi_transport_spi.h>
29 
30 #include "esp_scsi.h"
31 
32 #define DRV_MODULE_NAME		"esp"
33 #define PFX DRV_MODULE_NAME	": "
34 #define DRV_VERSION		"2.000"
35 #define DRV_MODULE_RELDATE	"April 19, 2007"
36 
37 /* SCSI bus reset settle time in seconds.  */
38 static int esp_bus_reset_settle = 3;
39 
40 static u32 esp_debug;
41 #define ESP_DEBUG_INTR		0x00000001
42 #define ESP_DEBUG_SCSICMD	0x00000002
43 #define ESP_DEBUG_RESET		0x00000004
44 #define ESP_DEBUG_MSGIN		0x00000008
45 #define ESP_DEBUG_MSGOUT	0x00000010
46 #define ESP_DEBUG_CMDDONE	0x00000020
47 #define ESP_DEBUG_DISCONNECT	0x00000040
48 #define ESP_DEBUG_DATASTART	0x00000080
49 #define ESP_DEBUG_DATADONE	0x00000100
50 #define ESP_DEBUG_RECONNECT	0x00000200
51 #define ESP_DEBUG_AUTOSENSE	0x00000400
52 
53 #define esp_log_intr(f, a...) \
54 do {	if (esp_debug & ESP_DEBUG_INTR) \
55 		printk(f, ## a); \
56 } while (0)
57 
58 #define esp_log_reset(f, a...) \
59 do {	if (esp_debug & ESP_DEBUG_RESET) \
60 		printk(f, ## a); \
61 } while (0)
62 
63 #define esp_log_msgin(f, a...) \
64 do {	if (esp_debug & ESP_DEBUG_MSGIN) \
65 		printk(f, ## a); \
66 } while (0)
67 
68 #define esp_log_msgout(f, a...) \
69 do {	if (esp_debug & ESP_DEBUG_MSGOUT) \
70 		printk(f, ## a); \
71 } while (0)
72 
73 #define esp_log_cmddone(f, a...) \
74 do {	if (esp_debug & ESP_DEBUG_CMDDONE) \
75 		printk(f, ## a); \
76 } while (0)
77 
78 #define esp_log_disconnect(f, a...) \
79 do {	if (esp_debug & ESP_DEBUG_DISCONNECT) \
80 		printk(f, ## a); \
81 } while (0)
82 
83 #define esp_log_datastart(f, a...) \
84 do {	if (esp_debug & ESP_DEBUG_DATASTART) \
85 		printk(f, ## a); \
86 } while (0)
87 
88 #define esp_log_datadone(f, a...) \
89 do {	if (esp_debug & ESP_DEBUG_DATADONE) \
90 		printk(f, ## a); \
91 } while (0)
92 
93 #define esp_log_reconnect(f, a...) \
94 do {	if (esp_debug & ESP_DEBUG_RECONNECT) \
95 		printk(f, ## a); \
96 } while (0)
97 
98 #define esp_log_autosense(f, a...) \
99 do {	if (esp_debug & ESP_DEBUG_AUTOSENSE) \
100 		printk(f, ## a); \
101 } while (0)
102 
103 #define esp_read8(REG)		esp->ops->esp_read8(esp, REG)
104 #define esp_write8(VAL,REG)	esp->ops->esp_write8(esp, VAL, REG)
105 
106 static void esp_log_fill_regs(struct esp *esp,
107 			      struct esp_event_ent *p)
108 {
109 	p->sreg = esp->sreg;
110 	p->seqreg = esp->seqreg;
111 	p->sreg2 = esp->sreg2;
112 	p->ireg = esp->ireg;
113 	p->select_state = esp->select_state;
114 	p->event = esp->event;
115 }
116 
117 void scsi_esp_cmd(struct esp *esp, u8 val)
118 {
119 	struct esp_event_ent *p;
120 	int idx = esp->esp_event_cur;
121 
122 	p = &esp->esp_event_log[idx];
123 	p->type = ESP_EVENT_TYPE_CMD;
124 	p->val = val;
125 	esp_log_fill_regs(esp, p);
126 
127 	esp->esp_event_cur = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
128 
129 	esp_write8(val, ESP_CMD);
130 }
131 EXPORT_SYMBOL(scsi_esp_cmd);
132 
133 static void esp_event(struct esp *esp, u8 val)
134 {
135 	struct esp_event_ent *p;
136 	int idx = esp->esp_event_cur;
137 
138 	p = &esp->esp_event_log[idx];
139 	p->type = ESP_EVENT_TYPE_EVENT;
140 	p->val = val;
141 	esp_log_fill_regs(esp, p);
142 
143 	esp->esp_event_cur = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
144 
145 	esp->event = val;
146 }
147 
148 static void esp_dump_cmd_log(struct esp *esp)
149 {
150 	int idx = esp->esp_event_cur;
151 	int stop = idx;
152 
153 	printk(KERN_INFO PFX "esp%d: Dumping command log\n",
154 	       esp->host->unique_id);
155 	do {
156 		struct esp_event_ent *p = &esp->esp_event_log[idx];
157 
158 		printk(KERN_INFO PFX "esp%d: ent[%d] %s ",
159 		       esp->host->unique_id, idx,
160 		       p->type == ESP_EVENT_TYPE_CMD ? "CMD" : "EVENT");
161 
162 		printk("val[%02x] sreg[%02x] seqreg[%02x] "
163 		       "sreg2[%02x] ireg[%02x] ss[%02x] event[%02x]\n",
164 		       p->val, p->sreg, p->seqreg,
165 		       p->sreg2, p->ireg, p->select_state, p->event);
166 
167 		idx = (idx + 1) & (ESP_EVENT_LOG_SZ - 1);
168 	} while (idx != stop);
169 }
170 
171 static void esp_flush_fifo(struct esp *esp)
172 {
173 	scsi_esp_cmd(esp, ESP_CMD_FLUSH);
174 	if (esp->rev == ESP236) {
175 		int lim = 1000;
176 
177 		while (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES) {
178 			if (--lim == 0) {
179 				printk(KERN_ALERT PFX "esp%d: ESP_FF_BYTES "
180 				       "will not clear!\n",
181 				       esp->host->unique_id);
182 				break;
183 			}
184 			udelay(1);
185 		}
186 	}
187 }
188 
189 static void hme_read_fifo(struct esp *esp)
190 {
191 	int fcnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
192 	int idx = 0;
193 
194 	while (fcnt--) {
195 		esp->fifo[idx++] = esp_read8(ESP_FDATA);
196 		esp->fifo[idx++] = esp_read8(ESP_FDATA);
197 	}
198 	if (esp->sreg2 & ESP_STAT2_F1BYTE) {
199 		esp_write8(0, ESP_FDATA);
200 		esp->fifo[idx++] = esp_read8(ESP_FDATA);
201 		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
202 	}
203 	esp->fifo_cnt = idx;
204 }
205 
206 static void esp_set_all_config3(struct esp *esp, u8 val)
207 {
208 	int i;
209 
210 	for (i = 0; i < ESP_MAX_TARGET; i++)
211 		esp->target[i].esp_config3 = val;
212 }
213 
214 /* Reset the ESP chip, _not_ the SCSI bus. */
215 static void esp_reset_esp(struct esp *esp)
216 {
217 	u8 family_code, version;
218 
219 	/* Now reset the ESP chip */
220 	scsi_esp_cmd(esp, ESP_CMD_RC);
221 	scsi_esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);
222 	scsi_esp_cmd(esp, ESP_CMD_NULL | ESP_CMD_DMA);
223 
224 	/* Reload the configuration registers */
225 	esp_write8(esp->cfact, ESP_CFACT);
226 
227 	esp->prev_stp = 0;
228 	esp_write8(esp->prev_stp, ESP_STP);
229 
230 	esp->prev_soff = 0;
231 	esp_write8(esp->prev_soff, ESP_SOFF);
232 
233 	esp_write8(esp->neg_defp, ESP_TIMEO);
234 
235 	/* This is the only point at which it is reliable to read
236 	 * the ID-code for a fast ESP chip variants.
237 	 */
238 	esp->max_period = ((35 * esp->ccycle) / 1000);
239 	if (esp->rev == FAST) {
240 		version = esp_read8(ESP_UID);
241 		family_code = (version & 0xf8) >> 3;
242 		if (family_code == 0x02)
243 			esp->rev = FAS236;
244 		else if (family_code == 0x0a)
245 			esp->rev = FASHME; /* Version is usually '5'. */
246 		else
247 			esp->rev = FAS100A;
248 		esp->min_period = ((4 * esp->ccycle) / 1000);
249 	} else {
250 		esp->min_period = ((5 * esp->ccycle) / 1000);
251 	}
252 	esp->max_period = (esp->max_period + 3)>>2;
253 	esp->min_period = (esp->min_period + 3)>>2;
254 
255 	esp_write8(esp->config1, ESP_CFG1);
256 	switch (esp->rev) {
257 	case ESP100:
258 		/* nothing to do */
259 		break;
260 
261 	case ESP100A:
262 		esp_write8(esp->config2, ESP_CFG2);
263 		break;
264 
265 	case ESP236:
266 		/* Slow 236 */
267 		esp_write8(esp->config2, ESP_CFG2);
268 		esp->prev_cfg3 = esp->target[0].esp_config3;
269 		esp_write8(esp->prev_cfg3, ESP_CFG3);
270 		break;
271 
272 	case FASHME:
273 		esp->config2 |= (ESP_CONFIG2_HME32 | ESP_CONFIG2_HMEFENAB);
274 		/* fallthrough... */
275 
276 	case FAS236:
277 		/* Fast 236 or HME */
278 		esp_write8(esp->config2, ESP_CFG2);
279 		if (esp->rev == FASHME) {
280 			u8 cfg3 = esp->target[0].esp_config3;
281 
282 			cfg3 |= ESP_CONFIG3_FCLOCK | ESP_CONFIG3_OBPUSH;
283 			if (esp->scsi_id >= 8)
284 				cfg3 |= ESP_CONFIG3_IDBIT3;
285 			esp_set_all_config3(esp, cfg3);
286 		} else {
287 			u32 cfg3 = esp->target[0].esp_config3;
288 
289 			cfg3 |= ESP_CONFIG3_FCLK;
290 			esp_set_all_config3(esp, cfg3);
291 		}
292 		esp->prev_cfg3 = esp->target[0].esp_config3;
293 		esp_write8(esp->prev_cfg3, ESP_CFG3);
294 		if (esp->rev == FASHME) {
295 			esp->radelay = 80;
296 		} else {
297 			if (esp->flags & ESP_FLAG_DIFFERENTIAL)
298 				esp->radelay = 0;
299 			else
300 				esp->radelay = 96;
301 		}
302 		break;
303 
304 	case FAS100A:
305 		/* Fast 100a */
306 		esp_write8(esp->config2, ESP_CFG2);
307 		esp_set_all_config3(esp,
308 				    (esp->target[0].esp_config3 |
309 				     ESP_CONFIG3_FCLOCK));
310 		esp->prev_cfg3 = esp->target[0].esp_config3;
311 		esp_write8(esp->prev_cfg3, ESP_CFG3);
312 		esp->radelay = 32;
313 		break;
314 
315 	default:
316 		break;
317 	}
318 
319 	/* Eat any bitrot in the chip */
320 	esp_read8(ESP_INTRPT);
321 	udelay(100);
322 }
323 
324 static void esp_map_dma(struct esp *esp, struct scsi_cmnd *cmd)
325 {
326 	struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
327 	struct scatterlist *sg = cmd->request_buffer;
328 	int dir = cmd->sc_data_direction;
329 	int total, i;
330 
331 	if (dir == DMA_NONE)
332 		return;
333 
334 	BUG_ON(cmd->use_sg == 0);
335 
336 	spriv->u.num_sg = esp->ops->map_sg(esp, sg,
337 					   cmd->use_sg, dir);
338 	spriv->cur_residue = sg_dma_len(sg);
339 	spriv->cur_sg = sg;
340 
341 	total = 0;
342 	for (i = 0; i < spriv->u.num_sg; i++)
343 		total += sg_dma_len(&sg[i]);
344 	spriv->tot_residue = total;
345 }
346 
347 static dma_addr_t esp_cur_dma_addr(struct esp_cmd_entry *ent,
348 				   struct scsi_cmnd *cmd)
349 {
350 	struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
351 
352 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
353 		return ent->sense_dma +
354 			(ent->sense_ptr - cmd->sense_buffer);
355 	}
356 
357 	return sg_dma_address(p->cur_sg) +
358 		(sg_dma_len(p->cur_sg) -
359 		 p->cur_residue);
360 }
361 
362 static unsigned int esp_cur_dma_len(struct esp_cmd_entry *ent,
363 				    struct scsi_cmnd *cmd)
364 {
365 	struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
366 
367 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
368 		return SCSI_SENSE_BUFFERSIZE -
369 			(ent->sense_ptr - cmd->sense_buffer);
370 	}
371 	return p->cur_residue;
372 }
373 
374 static void esp_advance_dma(struct esp *esp, struct esp_cmd_entry *ent,
375 			    struct scsi_cmnd *cmd, unsigned int len)
376 {
377 	struct esp_cmd_priv *p = ESP_CMD_PRIV(cmd);
378 
379 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
380 		ent->sense_ptr += len;
381 		return;
382 	}
383 
384 	p->cur_residue -= len;
385 	p->tot_residue -= len;
386 	if (p->cur_residue < 0 || p->tot_residue < 0) {
387 		printk(KERN_ERR PFX "esp%d: Data transfer overflow.\n",
388 		       esp->host->unique_id);
389 		printk(KERN_ERR PFX "esp%d: cur_residue[%d] tot_residue[%d] "
390 		       "len[%u]\n",
391 		       esp->host->unique_id,
392 		       p->cur_residue, p->tot_residue, len);
393 		p->cur_residue = 0;
394 		p->tot_residue = 0;
395 	}
396 	if (!p->cur_residue && p->tot_residue) {
397 		p->cur_sg++;
398 		p->cur_residue = sg_dma_len(p->cur_sg);
399 	}
400 }
401 
402 static void esp_unmap_dma(struct esp *esp, struct scsi_cmnd *cmd)
403 {
404 	struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
405 	int dir = cmd->sc_data_direction;
406 
407 	if (dir == DMA_NONE)
408 		return;
409 
410 	esp->ops->unmap_sg(esp, cmd->request_buffer,
411 			   spriv->u.num_sg, dir);
412 }
413 
414 static void esp_save_pointers(struct esp *esp, struct esp_cmd_entry *ent)
415 {
416 	struct scsi_cmnd *cmd = ent->cmd;
417 	struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
418 
419 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
420 		ent->saved_sense_ptr = ent->sense_ptr;
421 		return;
422 	}
423 	ent->saved_cur_residue = spriv->cur_residue;
424 	ent->saved_cur_sg = spriv->cur_sg;
425 	ent->saved_tot_residue = spriv->tot_residue;
426 }
427 
428 static void esp_restore_pointers(struct esp *esp, struct esp_cmd_entry *ent)
429 {
430 	struct scsi_cmnd *cmd = ent->cmd;
431 	struct esp_cmd_priv *spriv = ESP_CMD_PRIV(cmd);
432 
433 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
434 		ent->sense_ptr = ent->saved_sense_ptr;
435 		return;
436 	}
437 	spriv->cur_residue = ent->saved_cur_residue;
438 	spriv->cur_sg = ent->saved_cur_sg;
439 	spriv->tot_residue = ent->saved_tot_residue;
440 }
441 
442 static void esp_check_command_len(struct esp *esp, struct scsi_cmnd *cmd)
443 {
444 	if (cmd->cmd_len == 6 ||
445 	    cmd->cmd_len == 10 ||
446 	    cmd->cmd_len == 12) {
447 		esp->flags &= ~ESP_FLAG_DOING_SLOWCMD;
448 	} else {
449 		esp->flags |= ESP_FLAG_DOING_SLOWCMD;
450 	}
451 }
452 
453 static void esp_write_tgt_config3(struct esp *esp, int tgt)
454 {
455 	if (esp->rev > ESP100A) {
456 		u8 val = esp->target[tgt].esp_config3;
457 
458 		if (val != esp->prev_cfg3) {
459 			esp->prev_cfg3 = val;
460 			esp_write8(val, ESP_CFG3);
461 		}
462 	}
463 }
464 
465 static void esp_write_tgt_sync(struct esp *esp, int tgt)
466 {
467 	u8 off = esp->target[tgt].esp_offset;
468 	u8 per = esp->target[tgt].esp_period;
469 
470 	if (off != esp->prev_soff) {
471 		esp->prev_soff = off;
472 		esp_write8(off, ESP_SOFF);
473 	}
474 	if (per != esp->prev_stp) {
475 		esp->prev_stp = per;
476 		esp_write8(per, ESP_STP);
477 	}
478 }
479 
480 static u32 esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len)
481 {
482 	if (esp->rev == FASHME) {
483 		/* Arbitrary segment boundaries, 24-bit counts.  */
484 		if (dma_len > (1U << 24))
485 			dma_len = (1U << 24);
486 	} else {
487 		u32 base, end;
488 
489 		/* ESP chip limits other variants by 16-bits of transfer
490 		 * count.  Actually on FAS100A and FAS236 we could get
491 		 * 24-bits of transfer count by enabling ESP_CONFIG2_FENAB
492 		 * in the ESP_CFG2 register but that causes other unwanted
493 		 * changes so we don't use it currently.
494 		 */
495 		if (dma_len > (1U << 16))
496 			dma_len = (1U << 16);
497 
498 		/* All of the DMA variants hooked up to these chips
499 		 * cannot handle crossing a 24-bit address boundary.
500 		 */
501 		base = dma_addr & ((1U << 24) - 1U);
502 		end = base + dma_len;
503 		if (end > (1U << 24))
504 			end = (1U <<24);
505 		dma_len = end - base;
506 	}
507 	return dma_len;
508 }
509 
510 static int esp_need_to_nego_wide(struct esp_target_data *tp)
511 {
512 	struct scsi_target *target = tp->starget;
513 
514 	return spi_width(target) != tp->nego_goal_width;
515 }
516 
517 static int esp_need_to_nego_sync(struct esp_target_data *tp)
518 {
519 	struct scsi_target *target = tp->starget;
520 
521 	/* When offset is zero, period is "don't care".  */
522 	if (!spi_offset(target) && !tp->nego_goal_offset)
523 		return 0;
524 
525 	if (spi_offset(target) == tp->nego_goal_offset &&
526 	    spi_period(target) == tp->nego_goal_period)
527 		return 0;
528 
529 	return 1;
530 }
531 
532 static int esp_alloc_lun_tag(struct esp_cmd_entry *ent,
533 			     struct esp_lun_data *lp)
534 {
535 	if (!ent->tag[0]) {
536 		/* Non-tagged, slot already taken?  */
537 		if (lp->non_tagged_cmd)
538 			return -EBUSY;
539 
540 		if (lp->hold) {
541 			/* We are being held by active tagged
542 			 * commands.
543 			 */
544 			if (lp->num_tagged)
545 				return -EBUSY;
546 
547 			/* Tagged commands completed, we can unplug
548 			 * the queue and run this untagged command.
549 			 */
550 			lp->hold = 0;
551 		} else if (lp->num_tagged) {
552 			/* Plug the queue until num_tagged decreases
553 			 * to zero in esp_free_lun_tag.
554 			 */
555 			lp->hold = 1;
556 			return -EBUSY;
557 		}
558 
559 		lp->non_tagged_cmd = ent;
560 		return 0;
561 	} else {
562 		/* Tagged command, see if blocked by a
563 		 * non-tagged one.
564 		 */
565 		if (lp->non_tagged_cmd || lp->hold)
566 			return -EBUSY;
567 	}
568 
569 	BUG_ON(lp->tagged_cmds[ent->tag[1]]);
570 
571 	lp->tagged_cmds[ent->tag[1]] = ent;
572 	lp->num_tagged++;
573 
574 	return 0;
575 }
576 
577 static void esp_free_lun_tag(struct esp_cmd_entry *ent,
578 			     struct esp_lun_data *lp)
579 {
580 	if (ent->tag[0]) {
581 		BUG_ON(lp->tagged_cmds[ent->tag[1]] != ent);
582 		lp->tagged_cmds[ent->tag[1]] = NULL;
583 		lp->num_tagged--;
584 	} else {
585 		BUG_ON(lp->non_tagged_cmd != ent);
586 		lp->non_tagged_cmd = NULL;
587 	}
588 }
589 
590 /* When a contingent allegiance conditon is created, we force feed a
591  * REQUEST_SENSE command to the device to fetch the sense data.  I
592  * tried many other schemes, relying on the scsi error handling layer
593  * to send out the REQUEST_SENSE automatically, but this was difficult
594  * to get right especially in the presence of applications like smartd
595  * which use SG_IO to send out their own REQUEST_SENSE commands.
596  */
597 static void esp_autosense(struct esp *esp, struct esp_cmd_entry *ent)
598 {
599 	struct scsi_cmnd *cmd = ent->cmd;
600 	struct scsi_device *dev = cmd->device;
601 	int tgt, lun;
602 	u8 *p, val;
603 
604 	tgt = dev->id;
605 	lun = dev->lun;
606 
607 
608 	if (!ent->sense_ptr) {
609 		esp_log_autosense("esp%d: Doing auto-sense for "
610 				  "tgt[%d] lun[%d]\n",
611 				  esp->host->unique_id, tgt, lun);
612 
613 		ent->sense_ptr = cmd->sense_buffer;
614 		ent->sense_dma = esp->ops->map_single(esp,
615 						      ent->sense_ptr,
616 						      SCSI_SENSE_BUFFERSIZE,
617 						      DMA_FROM_DEVICE);
618 	}
619 	ent->saved_sense_ptr = ent->sense_ptr;
620 
621 	esp->active_cmd = ent;
622 
623 	p = esp->command_block;
624 	esp->msg_out_len = 0;
625 
626 	*p++ = IDENTIFY(0, lun);
627 	*p++ = REQUEST_SENSE;
628 	*p++ = ((dev->scsi_level <= SCSI_2) ?
629 		(lun << 5) : 0);
630 	*p++ = 0;
631 	*p++ = 0;
632 	*p++ = SCSI_SENSE_BUFFERSIZE;
633 	*p++ = 0;
634 
635 	esp->select_state = ESP_SELECT_BASIC;
636 
637 	val = tgt;
638 	if (esp->rev == FASHME)
639 		val |= ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT;
640 	esp_write8(val, ESP_BUSID);
641 
642 	esp_write_tgt_sync(esp, tgt);
643 	esp_write_tgt_config3(esp, tgt);
644 
645 	val = (p - esp->command_block);
646 
647 	if (esp->rev == FASHME)
648 		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
649 	esp->ops->send_dma_cmd(esp, esp->command_block_dma,
650 			       val, 16, 0, ESP_CMD_DMA | ESP_CMD_SELA);
651 }
652 
653 static struct esp_cmd_entry *find_and_prep_issuable_command(struct esp *esp)
654 {
655 	struct esp_cmd_entry *ent;
656 
657 	list_for_each_entry(ent, &esp->queued_cmds, list) {
658 		struct scsi_cmnd *cmd = ent->cmd;
659 		struct scsi_device *dev = cmd->device;
660 		struct esp_lun_data *lp = dev->hostdata;
661 
662 		if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
663 			ent->tag[0] = 0;
664 			ent->tag[1] = 0;
665 			return ent;
666 		}
667 
668 		if (!scsi_populate_tag_msg(cmd, &ent->tag[0])) {
669 			ent->tag[0] = 0;
670 			ent->tag[1] = 0;
671 		}
672 
673 		if (esp_alloc_lun_tag(ent, lp) < 0)
674 			continue;
675 
676 		return ent;
677 	}
678 
679 	return NULL;
680 }
681 
682 static void esp_maybe_execute_command(struct esp *esp)
683 {
684 	struct esp_target_data *tp;
685 	struct esp_lun_data *lp;
686 	struct scsi_device *dev;
687 	struct scsi_cmnd *cmd;
688 	struct esp_cmd_entry *ent;
689 	int tgt, lun, i;
690 	u32 val, start_cmd;
691 	u8 *p;
692 
693 	if (esp->active_cmd ||
694 	    (esp->flags & ESP_FLAG_RESETTING))
695 		return;
696 
697 	ent = find_and_prep_issuable_command(esp);
698 	if (!ent)
699 		return;
700 
701 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
702 		esp_autosense(esp, ent);
703 		return;
704 	}
705 
706 	cmd = ent->cmd;
707 	dev = cmd->device;
708 	tgt = dev->id;
709 	lun = dev->lun;
710 	tp = &esp->target[tgt];
711 	lp = dev->hostdata;
712 
713 	list_del(&ent->list);
714 	list_add(&ent->list, &esp->active_cmds);
715 
716 	esp->active_cmd = ent;
717 
718 	esp_map_dma(esp, cmd);
719 	esp_save_pointers(esp, ent);
720 
721 	esp_check_command_len(esp, cmd);
722 
723 	p = esp->command_block;
724 
725 	esp->msg_out_len = 0;
726 	if (tp->flags & ESP_TGT_CHECK_NEGO) {
727 		/* Need to negotiate.  If the target is broken
728 		 * go for synchronous transfers and non-wide.
729 		 */
730 		if (tp->flags & ESP_TGT_BROKEN) {
731 			tp->flags &= ~ESP_TGT_DISCONNECT;
732 			tp->nego_goal_period = 0;
733 			tp->nego_goal_offset = 0;
734 			tp->nego_goal_width = 0;
735 			tp->nego_goal_tags = 0;
736 		}
737 
738 		/* If the settings are not changing, skip this.  */
739 		if (spi_width(tp->starget) == tp->nego_goal_width &&
740 		    spi_period(tp->starget) == tp->nego_goal_period &&
741 		    spi_offset(tp->starget) == tp->nego_goal_offset) {
742 			tp->flags &= ~ESP_TGT_CHECK_NEGO;
743 			goto build_identify;
744 		}
745 
746 		if (esp->rev == FASHME && esp_need_to_nego_wide(tp)) {
747 			esp->msg_out_len =
748 				spi_populate_width_msg(&esp->msg_out[0],
749 						       (tp->nego_goal_width ?
750 							1 : 0));
751 			tp->flags |= ESP_TGT_NEGO_WIDE;
752 		} else if (esp_need_to_nego_sync(tp)) {
753 			esp->msg_out_len =
754 				spi_populate_sync_msg(&esp->msg_out[0],
755 						      tp->nego_goal_period,
756 						      tp->nego_goal_offset);
757 			tp->flags |= ESP_TGT_NEGO_SYNC;
758 		} else {
759 			tp->flags &= ~ESP_TGT_CHECK_NEGO;
760 		}
761 
762 		/* Process it like a slow command.  */
763 		if (tp->flags & (ESP_TGT_NEGO_WIDE | ESP_TGT_NEGO_SYNC))
764 			esp->flags |= ESP_FLAG_DOING_SLOWCMD;
765 	}
766 
767 build_identify:
768 	/* If we don't have a lun-data struct yet, we're probing
769 	 * so do not disconnect.  Also, do not disconnect unless
770 	 * we have a tag on this command.
771 	 */
772 	if (lp && (tp->flags & ESP_TGT_DISCONNECT) && ent->tag[0])
773 		*p++ = IDENTIFY(1, lun);
774 	else
775 		*p++ = IDENTIFY(0, lun);
776 
777 	if (ent->tag[0] && esp->rev == ESP100) {
778 		/* ESP100 lacks select w/atn3 command, use select
779 		 * and stop instead.
780 		 */
781 		esp->flags |= ESP_FLAG_DOING_SLOWCMD;
782 	}
783 
784 	if (!(esp->flags & ESP_FLAG_DOING_SLOWCMD)) {
785 		start_cmd = ESP_CMD_DMA | ESP_CMD_SELA;
786 		if (ent->tag[0]) {
787 			*p++ = ent->tag[0];
788 			*p++ = ent->tag[1];
789 
790 			start_cmd = ESP_CMD_DMA | ESP_CMD_SA3;
791 		}
792 
793 		for (i = 0; i < cmd->cmd_len; i++)
794 			*p++ = cmd->cmnd[i];
795 
796 		esp->select_state = ESP_SELECT_BASIC;
797 	} else {
798 		esp->cmd_bytes_left = cmd->cmd_len;
799 		esp->cmd_bytes_ptr = &cmd->cmnd[0];
800 
801 		if (ent->tag[0]) {
802 			for (i = esp->msg_out_len - 1;
803 			     i >= 0; i--)
804 				esp->msg_out[i + 2] = esp->msg_out[i];
805 			esp->msg_out[0] = ent->tag[0];
806 			esp->msg_out[1] = ent->tag[1];
807 			esp->msg_out_len += 2;
808 		}
809 
810 		start_cmd = ESP_CMD_DMA | ESP_CMD_SELAS;
811 		esp->select_state = ESP_SELECT_MSGOUT;
812 	}
813 	val = tgt;
814 	if (esp->rev == FASHME)
815 		val |= ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT;
816 	esp_write8(val, ESP_BUSID);
817 
818 	esp_write_tgt_sync(esp, tgt);
819 	esp_write_tgt_config3(esp, tgt);
820 
821 	val = (p - esp->command_block);
822 
823 	if (esp_debug & ESP_DEBUG_SCSICMD) {
824 		printk("ESP: tgt[%d] lun[%d] scsi_cmd [ ", tgt, lun);
825 		for (i = 0; i < cmd->cmd_len; i++)
826 			printk("%02x ", cmd->cmnd[i]);
827 		printk("]\n");
828 	}
829 
830 	if (esp->rev == FASHME)
831 		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
832 	esp->ops->send_dma_cmd(esp, esp->command_block_dma,
833 			       val, 16, 0, start_cmd);
834 }
835 
836 static struct esp_cmd_entry *esp_get_ent(struct esp *esp)
837 {
838 	struct list_head *head = &esp->esp_cmd_pool;
839 	struct esp_cmd_entry *ret;
840 
841 	if (list_empty(head)) {
842 		ret = kzalloc(sizeof(struct esp_cmd_entry), GFP_ATOMIC);
843 	} else {
844 		ret = list_entry(head->next, struct esp_cmd_entry, list);
845 		list_del(&ret->list);
846 		memset(ret, 0, sizeof(*ret));
847 	}
848 	return ret;
849 }
850 
851 static void esp_put_ent(struct esp *esp, struct esp_cmd_entry *ent)
852 {
853 	list_add(&ent->list, &esp->esp_cmd_pool);
854 }
855 
856 static void esp_cmd_is_done(struct esp *esp, struct esp_cmd_entry *ent,
857 			    struct scsi_cmnd *cmd, unsigned int result)
858 {
859 	struct scsi_device *dev = cmd->device;
860 	int tgt = dev->id;
861 	int lun = dev->lun;
862 
863 	esp->active_cmd = NULL;
864 	esp_unmap_dma(esp, cmd);
865 	esp_free_lun_tag(ent, dev->hostdata);
866 	cmd->result = result;
867 
868 	if (ent->eh_done) {
869 		complete(ent->eh_done);
870 		ent->eh_done = NULL;
871 	}
872 
873 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
874 		esp->ops->unmap_single(esp, ent->sense_dma,
875 				       SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
876 		ent->sense_ptr = NULL;
877 
878 		/* Restore the message/status bytes to what we actually
879 		 * saw originally.  Also, report that we are providing
880 		 * the sense data.
881 		 */
882 		cmd->result = ((DRIVER_SENSE << 24) |
883 			       (DID_OK << 16) |
884 			       (COMMAND_COMPLETE << 8) |
885 			       (SAM_STAT_CHECK_CONDITION << 0));
886 
887 		ent->flags &= ~ESP_CMD_FLAG_AUTOSENSE;
888 		if (esp_debug & ESP_DEBUG_AUTOSENSE) {
889 			int i;
890 
891 			printk("esp%d: tgt[%d] lun[%d] AUTO SENSE[ ",
892 			       esp->host->unique_id, tgt, lun);
893 			for (i = 0; i < 18; i++)
894 				printk("%02x ", cmd->sense_buffer[i]);
895 			printk("]\n");
896 		}
897 	}
898 
899 	cmd->scsi_done(cmd);
900 
901 	list_del(&ent->list);
902 	esp_put_ent(esp, ent);
903 
904 	esp_maybe_execute_command(esp);
905 }
906 
907 static unsigned int compose_result(unsigned int status, unsigned int message,
908 				   unsigned int driver_code)
909 {
910 	return (status | (message << 8) | (driver_code << 16));
911 }
912 
913 static void esp_event_queue_full(struct esp *esp, struct esp_cmd_entry *ent)
914 {
915 	struct scsi_device *dev = ent->cmd->device;
916 	struct esp_lun_data *lp = dev->hostdata;
917 
918 	scsi_track_queue_full(dev, lp->num_tagged - 1);
919 }
920 
921 static int esp_queuecommand(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
922 {
923 	struct scsi_device *dev = cmd->device;
924 	struct esp *esp = host_to_esp(dev->host);
925 	struct esp_cmd_priv *spriv;
926 	struct esp_cmd_entry *ent;
927 
928 	ent = esp_get_ent(esp);
929 	if (!ent)
930 		return SCSI_MLQUEUE_HOST_BUSY;
931 
932 	ent->cmd = cmd;
933 
934 	cmd->scsi_done = done;
935 
936 	spriv = ESP_CMD_PRIV(cmd);
937 	spriv->u.dma_addr = ~(dma_addr_t)0x0;
938 
939 	list_add_tail(&ent->list, &esp->queued_cmds);
940 
941 	esp_maybe_execute_command(esp);
942 
943 	return 0;
944 }
945 
946 static int esp_check_gross_error(struct esp *esp)
947 {
948 	if (esp->sreg & ESP_STAT_SPAM) {
949 		/* Gross Error, could be one of:
950 		 * - top of fifo overwritten
951 		 * - top of command register overwritten
952 		 * - DMA programmed with wrong direction
953 		 * - improper phase change
954 		 */
955 		printk(KERN_ERR PFX "esp%d: Gross error sreg[%02x]\n",
956 		       esp->host->unique_id, esp->sreg);
957 		/* XXX Reset the chip. XXX */
958 		return 1;
959 	}
960 	return 0;
961 }
962 
963 static int esp_check_spur_intr(struct esp *esp)
964 {
965 	switch (esp->rev) {
966 	case ESP100:
967 	case ESP100A:
968 		/* The interrupt pending bit of the status register cannot
969 		 * be trusted on these revisions.
970 		 */
971 		esp->sreg &= ~ESP_STAT_INTR;
972 		break;
973 
974 	default:
975 		if (!(esp->sreg & ESP_STAT_INTR)) {
976 			esp->ireg = esp_read8(ESP_INTRPT);
977 			if (esp->ireg & ESP_INTR_SR)
978 				return 1;
979 
980 			/* If the DMA is indicating interrupt pending and the
981 			 * ESP is not, the only possibility is a DMA error.
982 			 */
983 			if (!esp->ops->dma_error(esp)) {
984 				printk(KERN_ERR PFX "esp%d: Spurious irq, "
985 				       "sreg=%x.\n",
986 				       esp->host->unique_id, esp->sreg);
987 				return -1;
988 			}
989 
990 			printk(KERN_ERR PFX "esp%d: DMA error\n",
991 			       esp->host->unique_id);
992 
993 			/* XXX Reset the chip. XXX */
994 			return -1;
995 		}
996 		break;
997 	}
998 
999 	return 0;
1000 }
1001 
1002 static void esp_schedule_reset(struct esp *esp)
1003 {
1004 	esp_log_reset("ESP: esp_schedule_reset() from %p\n",
1005 		      __builtin_return_address(0));
1006 	esp->flags |= ESP_FLAG_RESETTING;
1007 	esp_event(esp, ESP_EVENT_RESET);
1008 }
1009 
1010 /* In order to avoid having to add a special half-reconnected state
1011  * into the driver we just sit here and poll through the rest of
1012  * the reselection process to get the tag message bytes.
1013  */
1014 static struct esp_cmd_entry *esp_reconnect_with_tag(struct esp *esp,
1015 						    struct esp_lun_data *lp)
1016 {
1017 	struct esp_cmd_entry *ent;
1018 	int i;
1019 
1020 	if (!lp->num_tagged) {
1021 		printk(KERN_ERR PFX "esp%d: Reconnect w/num_tagged==0\n",
1022 		       esp->host->unique_id);
1023 		return NULL;
1024 	}
1025 
1026 	esp_log_reconnect("ESP: reconnect tag, ");
1027 
1028 	for (i = 0; i < ESP_QUICKIRQ_LIMIT; i++) {
1029 		if (esp->ops->irq_pending(esp))
1030 			break;
1031 	}
1032 	if (i == ESP_QUICKIRQ_LIMIT) {
1033 		printk(KERN_ERR PFX "esp%d: Reconnect IRQ1 timeout\n",
1034 		       esp->host->unique_id);
1035 		return NULL;
1036 	}
1037 
1038 	esp->sreg = esp_read8(ESP_STATUS);
1039 	esp->ireg = esp_read8(ESP_INTRPT);
1040 
1041 	esp_log_reconnect("IRQ(%d:%x:%x), ",
1042 			  i, esp->ireg, esp->sreg);
1043 
1044 	if (esp->ireg & ESP_INTR_DC) {
1045 		printk(KERN_ERR PFX "esp%d: Reconnect, got disconnect.\n",
1046 		       esp->host->unique_id);
1047 		return NULL;
1048 	}
1049 
1050 	if ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP) {
1051 		printk(KERN_ERR PFX "esp%d: Reconnect, not MIP sreg[%02x].\n",
1052 		       esp->host->unique_id, esp->sreg);
1053 		return NULL;
1054 	}
1055 
1056 	/* DMA in the tag bytes... */
1057 	esp->command_block[0] = 0xff;
1058 	esp->command_block[1] = 0xff;
1059 	esp->ops->send_dma_cmd(esp, esp->command_block_dma,
1060 			       2, 2, 1, ESP_CMD_DMA | ESP_CMD_TI);
1061 
1062 	/* ACK the msssage.  */
1063 	scsi_esp_cmd(esp, ESP_CMD_MOK);
1064 
1065 	for (i = 0; i < ESP_RESELECT_TAG_LIMIT; i++) {
1066 		if (esp->ops->irq_pending(esp)) {
1067 			esp->sreg = esp_read8(ESP_STATUS);
1068 			esp->ireg = esp_read8(ESP_INTRPT);
1069 			if (esp->ireg & ESP_INTR_FDONE)
1070 				break;
1071 		}
1072 		udelay(1);
1073 	}
1074 	if (i == ESP_RESELECT_TAG_LIMIT) {
1075 		printk(KERN_ERR PFX "esp%d: Reconnect IRQ2 timeout\n",
1076 		       esp->host->unique_id);
1077 		return NULL;
1078 	}
1079 	esp->ops->dma_drain(esp);
1080 	esp->ops->dma_invalidate(esp);
1081 
1082 	esp_log_reconnect("IRQ2(%d:%x:%x) tag[%x:%x]\n",
1083 			  i, esp->ireg, esp->sreg,
1084 			  esp->command_block[0],
1085 			  esp->command_block[1]);
1086 
1087 	if (esp->command_block[0] < SIMPLE_QUEUE_TAG ||
1088 	    esp->command_block[0] > ORDERED_QUEUE_TAG) {
1089 		printk(KERN_ERR PFX "esp%d: Reconnect, bad tag "
1090 		       "type %02x.\n",
1091 		       esp->host->unique_id, esp->command_block[0]);
1092 		return NULL;
1093 	}
1094 
1095 	ent = lp->tagged_cmds[esp->command_block[1]];
1096 	if (!ent) {
1097 		printk(KERN_ERR PFX "esp%d: Reconnect, no entry for "
1098 		       "tag %02x.\n",
1099 		       esp->host->unique_id, esp->command_block[1]);
1100 		return NULL;
1101 	}
1102 
1103 	return ent;
1104 }
1105 
1106 static int esp_reconnect(struct esp *esp)
1107 {
1108 	struct esp_cmd_entry *ent;
1109 	struct esp_target_data *tp;
1110 	struct esp_lun_data *lp;
1111 	struct scsi_device *dev;
1112 	int target, lun;
1113 
1114 	BUG_ON(esp->active_cmd);
1115 	if (esp->rev == FASHME) {
1116 		/* FASHME puts the target and lun numbers directly
1117 		 * into the fifo.
1118 		 */
1119 		target = esp->fifo[0];
1120 		lun = esp->fifo[1] & 0x7;
1121 	} else {
1122 		u8 bits = esp_read8(ESP_FDATA);
1123 
1124 		/* Older chips put the lun directly into the fifo, but
1125 		 * the target is given as a sample of the arbitration
1126 		 * lines on the bus at reselection time.  So we should
1127 		 * see the ID of the ESP and the one reconnecting target
1128 		 * set in the bitmap.
1129 		 */
1130 		if (!(bits & esp->scsi_id_mask))
1131 			goto do_reset;
1132 		bits &= ~esp->scsi_id_mask;
1133 		if (!bits || (bits & (bits - 1)))
1134 			goto do_reset;
1135 
1136 		target = ffs(bits) - 1;
1137 		lun = (esp_read8(ESP_FDATA) & 0x7);
1138 
1139 		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
1140 		if (esp->rev == ESP100) {
1141 			u8 ireg = esp_read8(ESP_INTRPT);
1142 			/* This chip has a bug during reselection that can
1143 			 * cause a spurious illegal-command interrupt, which
1144 			 * we simply ACK here.  Another possibility is a bus
1145 			 * reset so we must check for that.
1146 			 */
1147 			if (ireg & ESP_INTR_SR)
1148 				goto do_reset;
1149 		}
1150 		scsi_esp_cmd(esp, ESP_CMD_NULL);
1151 	}
1152 
1153 	esp_write_tgt_sync(esp, target);
1154 	esp_write_tgt_config3(esp, target);
1155 
1156 	scsi_esp_cmd(esp, ESP_CMD_MOK);
1157 
1158 	if (esp->rev == FASHME)
1159 		esp_write8(target | ESP_BUSID_RESELID | ESP_BUSID_CTR32BIT,
1160 			   ESP_BUSID);
1161 
1162 	tp = &esp->target[target];
1163 	dev = __scsi_device_lookup_by_target(tp->starget, lun);
1164 	if (!dev) {
1165 		printk(KERN_ERR PFX "esp%d: Reconnect, no lp "
1166 		       "tgt[%u] lun[%u]\n",
1167 		       esp->host->unique_id, target, lun);
1168 		goto do_reset;
1169 	}
1170 	lp = dev->hostdata;
1171 
1172 	ent = lp->non_tagged_cmd;
1173 	if (!ent) {
1174 		ent = esp_reconnect_with_tag(esp, lp);
1175 		if (!ent)
1176 			goto do_reset;
1177 	}
1178 
1179 	esp->active_cmd = ent;
1180 
1181 	if (ent->flags & ESP_CMD_FLAG_ABORT) {
1182 		esp->msg_out[0] = ABORT_TASK_SET;
1183 		esp->msg_out_len = 1;
1184 		scsi_esp_cmd(esp, ESP_CMD_SATN);
1185 	}
1186 
1187 	esp_event(esp, ESP_EVENT_CHECK_PHASE);
1188 	esp_restore_pointers(esp, ent);
1189 	esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
1190 	return 1;
1191 
1192 do_reset:
1193 	esp_schedule_reset(esp);
1194 	return 0;
1195 }
1196 
1197 static int esp_finish_select(struct esp *esp)
1198 {
1199 	struct esp_cmd_entry *ent;
1200 	struct scsi_cmnd *cmd;
1201 	u8 orig_select_state;
1202 
1203 	orig_select_state = esp->select_state;
1204 
1205 	/* No longer selecting.  */
1206 	esp->select_state = ESP_SELECT_NONE;
1207 
1208 	esp->seqreg = esp_read8(ESP_SSTEP) & ESP_STEP_VBITS;
1209 	ent = esp->active_cmd;
1210 	cmd = ent->cmd;
1211 
1212 	if (esp->ops->dma_error(esp)) {
1213 		/* If we see a DMA error during or as a result of selection,
1214 		 * all bets are off.
1215 		 */
1216 		esp_schedule_reset(esp);
1217 		esp_cmd_is_done(esp, ent, cmd, (DID_ERROR << 16));
1218 		return 0;
1219 	}
1220 
1221 	esp->ops->dma_invalidate(esp);
1222 
1223 	if (esp->ireg == (ESP_INTR_RSEL | ESP_INTR_FDONE)) {
1224 		struct esp_target_data *tp = &esp->target[cmd->device->id];
1225 
1226 		/* Carefully back out of the selection attempt.  Release
1227 		 * resources (such as DMA mapping & TAG) and reset state (such
1228 		 * as message out and command delivery variables).
1229 		 */
1230 		if (!(ent->flags & ESP_CMD_FLAG_AUTOSENSE)) {
1231 			esp_unmap_dma(esp, cmd);
1232 			esp_free_lun_tag(ent, cmd->device->hostdata);
1233 			tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_NEGO_WIDE);
1234 			esp->flags &= ~ESP_FLAG_DOING_SLOWCMD;
1235 			esp->cmd_bytes_ptr = NULL;
1236 			esp->cmd_bytes_left = 0;
1237 		} else {
1238 			esp->ops->unmap_single(esp, ent->sense_dma,
1239 					       SCSI_SENSE_BUFFERSIZE,
1240 					       DMA_FROM_DEVICE);
1241 			ent->sense_ptr = NULL;
1242 		}
1243 
1244 		/* Now that the state is unwound properly, put back onto
1245 		 * the issue queue.  This command is no longer active.
1246 		 */
1247 		list_del(&ent->list);
1248 		list_add(&ent->list, &esp->queued_cmds);
1249 		esp->active_cmd = NULL;
1250 
1251 		/* Return value ignored by caller, it directly invokes
1252 		 * esp_reconnect().
1253 		 */
1254 		return 0;
1255 	}
1256 
1257 	if (esp->ireg == ESP_INTR_DC) {
1258 		struct scsi_device *dev = cmd->device;
1259 
1260 		/* Disconnect.  Make sure we re-negotiate sync and
1261 		 * wide parameters if this target starts responding
1262 		 * again in the future.
1263 		 */
1264 		esp->target[dev->id].flags |= ESP_TGT_CHECK_NEGO;
1265 
1266 		scsi_esp_cmd(esp, ESP_CMD_ESEL);
1267 		esp_cmd_is_done(esp, ent, cmd, (DID_BAD_TARGET << 16));
1268 		return 1;
1269 	}
1270 
1271 	if (esp->ireg == (ESP_INTR_FDONE | ESP_INTR_BSERV)) {
1272 		/* Selection successful.  On pre-FAST chips we have
1273 		 * to do a NOP and possibly clean out the FIFO.
1274 		 */
1275 		if (esp->rev <= ESP236) {
1276 			int fcnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
1277 
1278 			scsi_esp_cmd(esp, ESP_CMD_NULL);
1279 
1280 			if (!fcnt &&
1281 			    (!esp->prev_soff ||
1282 			     ((esp->sreg & ESP_STAT_PMASK) != ESP_DIP)))
1283 				esp_flush_fifo(esp);
1284 		}
1285 
1286 		/* If we are doing a slow command, negotiation, etc.
1287 		 * we'll do the right thing as we transition to the
1288 		 * next phase.
1289 		 */
1290 		esp_event(esp, ESP_EVENT_CHECK_PHASE);
1291 		return 0;
1292 	}
1293 
1294 	printk("ESP: Unexpected selection completion ireg[%x].\n",
1295 	       esp->ireg);
1296 	esp_schedule_reset(esp);
1297 	return 0;
1298 }
1299 
1300 static int esp_data_bytes_sent(struct esp *esp, struct esp_cmd_entry *ent,
1301 			       struct scsi_cmnd *cmd)
1302 {
1303 	int fifo_cnt, ecount, bytes_sent, flush_fifo;
1304 
1305 	fifo_cnt = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
1306 	if (esp->prev_cfg3 & ESP_CONFIG3_EWIDE)
1307 		fifo_cnt <<= 1;
1308 
1309 	ecount = 0;
1310 	if (!(esp->sreg & ESP_STAT_TCNT)) {
1311 		ecount = ((unsigned int)esp_read8(ESP_TCLOW) |
1312 			  (((unsigned int)esp_read8(ESP_TCMED)) << 8));
1313 		if (esp->rev == FASHME)
1314 			ecount |= ((unsigned int)esp_read8(FAS_RLO)) << 16;
1315 	}
1316 
1317 	bytes_sent = esp->data_dma_len;
1318 	bytes_sent -= ecount;
1319 
1320 	if (!(ent->flags & ESP_CMD_FLAG_WRITE))
1321 		bytes_sent -= fifo_cnt;
1322 
1323 	flush_fifo = 0;
1324 	if (!esp->prev_soff) {
1325 		/* Synchronous data transfer, always flush fifo. */
1326 		flush_fifo = 1;
1327 	} else {
1328 		if (esp->rev == ESP100) {
1329 			u32 fflags, phase;
1330 
1331 			/* ESP100 has a chip bug where in the synchronous data
1332 			 * phase it can mistake a final long REQ pulse from the
1333 			 * target as an extra data byte.  Fun.
1334 			 *
1335 			 * To detect this case we resample the status register
1336 			 * and fifo flags.  If we're still in a data phase and
1337 			 * we see spurious chunks in the fifo, we return error
1338 			 * to the caller which should reset and set things up
1339 			 * such that we only try future transfers to this
1340 			 * target in synchronous mode.
1341 			 */
1342 			esp->sreg = esp_read8(ESP_STATUS);
1343 			phase = esp->sreg & ESP_STAT_PMASK;
1344 			fflags = esp_read8(ESP_FFLAGS);
1345 
1346 			if ((phase == ESP_DOP &&
1347 			     (fflags & ESP_FF_ONOTZERO)) ||
1348 			    (phase == ESP_DIP &&
1349 			     (fflags & ESP_FF_FBYTES)))
1350 				return -1;
1351 		}
1352 		if (!(ent->flags & ESP_CMD_FLAG_WRITE))
1353 			flush_fifo = 1;
1354 	}
1355 
1356 	if (flush_fifo)
1357 		esp_flush_fifo(esp);
1358 
1359 	return bytes_sent;
1360 }
1361 
1362 static void esp_setsync(struct esp *esp, struct esp_target_data *tp,
1363 			u8 scsi_period, u8 scsi_offset,
1364 			u8 esp_stp, u8 esp_soff)
1365 {
1366 	spi_period(tp->starget) = scsi_period;
1367 	spi_offset(tp->starget) = scsi_offset;
1368 	spi_width(tp->starget) = (tp->flags & ESP_TGT_WIDE) ? 1 : 0;
1369 
1370 	if (esp_soff) {
1371 		esp_stp &= 0x1f;
1372 		esp_soff |= esp->radelay;
1373 		if (esp->rev >= FAS236) {
1374 			u8 bit = ESP_CONFIG3_FSCSI;
1375 			if (esp->rev >= FAS100A)
1376 				bit = ESP_CONFIG3_FAST;
1377 
1378 			if (scsi_period < 50) {
1379 				if (esp->rev == FASHME)
1380 					esp_soff &= ~esp->radelay;
1381 				tp->esp_config3 |= bit;
1382 			} else {
1383 				tp->esp_config3 &= ~bit;
1384 			}
1385 			esp->prev_cfg3 = tp->esp_config3;
1386 			esp_write8(esp->prev_cfg3, ESP_CFG3);
1387 		}
1388 	}
1389 
1390 	tp->esp_period = esp->prev_stp = esp_stp;
1391 	tp->esp_offset = esp->prev_soff = esp_soff;
1392 
1393 	esp_write8(esp_soff, ESP_SOFF);
1394 	esp_write8(esp_stp, ESP_STP);
1395 
1396 	tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_CHECK_NEGO);
1397 
1398 	spi_display_xfer_agreement(tp->starget);
1399 }
1400 
1401 static void esp_msgin_reject(struct esp *esp)
1402 {
1403 	struct esp_cmd_entry *ent = esp->active_cmd;
1404 	struct scsi_cmnd *cmd = ent->cmd;
1405 	struct esp_target_data *tp;
1406 	int tgt;
1407 
1408 	tgt = cmd->device->id;
1409 	tp = &esp->target[tgt];
1410 
1411 	if (tp->flags & ESP_TGT_NEGO_WIDE) {
1412 		tp->flags &= ~(ESP_TGT_NEGO_WIDE | ESP_TGT_WIDE);
1413 
1414 		if (!esp_need_to_nego_sync(tp)) {
1415 			tp->flags &= ~ESP_TGT_CHECK_NEGO;
1416 			scsi_esp_cmd(esp, ESP_CMD_RATN);
1417 		} else {
1418 			esp->msg_out_len =
1419 				spi_populate_sync_msg(&esp->msg_out[0],
1420 						      tp->nego_goal_period,
1421 						      tp->nego_goal_offset);
1422 			tp->flags |= ESP_TGT_NEGO_SYNC;
1423 			scsi_esp_cmd(esp, ESP_CMD_SATN);
1424 		}
1425 		return;
1426 	}
1427 
1428 	if (tp->flags & ESP_TGT_NEGO_SYNC) {
1429 		tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_CHECK_NEGO);
1430 		tp->esp_period = 0;
1431 		tp->esp_offset = 0;
1432 		esp_setsync(esp, tp, 0, 0, 0, 0);
1433 		scsi_esp_cmd(esp, ESP_CMD_RATN);
1434 		return;
1435 	}
1436 
1437 	esp->msg_out[0] = ABORT_TASK_SET;
1438 	esp->msg_out_len = 1;
1439 	scsi_esp_cmd(esp, ESP_CMD_SATN);
1440 }
1441 
1442 static void esp_msgin_sdtr(struct esp *esp, struct esp_target_data *tp)
1443 {
1444 	u8 period = esp->msg_in[3];
1445 	u8 offset = esp->msg_in[4];
1446 	u8 stp;
1447 
1448 	if (!(tp->flags & ESP_TGT_NEGO_SYNC))
1449 		goto do_reject;
1450 
1451 	if (offset > 15)
1452 		goto do_reject;
1453 
1454 	if (offset) {
1455 		int rounded_up, one_clock;
1456 
1457 		if (period > esp->max_period) {
1458 			period = offset = 0;
1459 			goto do_sdtr;
1460 		}
1461 		if (period < esp->min_period)
1462 			goto do_reject;
1463 
1464 		one_clock = esp->ccycle / 1000;
1465 		rounded_up = (period << 2);
1466 		rounded_up = (rounded_up + one_clock - 1) / one_clock;
1467 		stp = rounded_up;
1468 		if (stp && esp->rev >= FAS236) {
1469 			if (stp >= 50)
1470 				stp--;
1471 		}
1472 	} else {
1473 		stp = 0;
1474 	}
1475 
1476 	esp_setsync(esp, tp, period, offset, stp, offset);
1477 	return;
1478 
1479 do_reject:
1480 	esp->msg_out[0] = MESSAGE_REJECT;
1481 	esp->msg_out_len = 1;
1482 	scsi_esp_cmd(esp, ESP_CMD_SATN);
1483 	return;
1484 
1485 do_sdtr:
1486 	tp->nego_goal_period = period;
1487 	tp->nego_goal_offset = offset;
1488 	esp->msg_out_len =
1489 		spi_populate_sync_msg(&esp->msg_out[0],
1490 				      tp->nego_goal_period,
1491 				      tp->nego_goal_offset);
1492 	scsi_esp_cmd(esp, ESP_CMD_SATN);
1493 }
1494 
1495 static void esp_msgin_wdtr(struct esp *esp, struct esp_target_data *tp)
1496 {
1497 	int size = 8 << esp->msg_in[3];
1498 	u8 cfg3;
1499 
1500 	if (esp->rev != FASHME)
1501 		goto do_reject;
1502 
1503 	if (size != 8 && size != 16)
1504 		goto do_reject;
1505 
1506 	if (!(tp->flags & ESP_TGT_NEGO_WIDE))
1507 		goto do_reject;
1508 
1509 	cfg3 = tp->esp_config3;
1510 	if (size == 16) {
1511 		tp->flags |= ESP_TGT_WIDE;
1512 		cfg3 |= ESP_CONFIG3_EWIDE;
1513 	} else {
1514 		tp->flags &= ~ESP_TGT_WIDE;
1515 		cfg3 &= ~ESP_CONFIG3_EWIDE;
1516 	}
1517 	tp->esp_config3 = cfg3;
1518 	esp->prev_cfg3 = cfg3;
1519 	esp_write8(cfg3, ESP_CFG3);
1520 
1521 	tp->flags &= ~ESP_TGT_NEGO_WIDE;
1522 
1523 	spi_period(tp->starget) = 0;
1524 	spi_offset(tp->starget) = 0;
1525 	if (!esp_need_to_nego_sync(tp)) {
1526 		tp->flags &= ~ESP_TGT_CHECK_NEGO;
1527 		scsi_esp_cmd(esp, ESP_CMD_RATN);
1528 	} else {
1529 		esp->msg_out_len =
1530 			spi_populate_sync_msg(&esp->msg_out[0],
1531 					      tp->nego_goal_period,
1532 					      tp->nego_goal_offset);
1533 		tp->flags |= ESP_TGT_NEGO_SYNC;
1534 		scsi_esp_cmd(esp, ESP_CMD_SATN);
1535 	}
1536 	return;
1537 
1538 do_reject:
1539 	esp->msg_out[0] = MESSAGE_REJECT;
1540 	esp->msg_out_len = 1;
1541 	scsi_esp_cmd(esp, ESP_CMD_SATN);
1542 }
1543 
1544 static void esp_msgin_extended(struct esp *esp)
1545 {
1546 	struct esp_cmd_entry *ent = esp->active_cmd;
1547 	struct scsi_cmnd *cmd = ent->cmd;
1548 	struct esp_target_data *tp;
1549 	int tgt = cmd->device->id;
1550 
1551 	tp = &esp->target[tgt];
1552 	if (esp->msg_in[2] == EXTENDED_SDTR) {
1553 		esp_msgin_sdtr(esp, tp);
1554 		return;
1555 	}
1556 	if (esp->msg_in[2] == EXTENDED_WDTR) {
1557 		esp_msgin_wdtr(esp, tp);
1558 		return;
1559 	}
1560 
1561 	printk("ESP: Unexpected extended msg type %x\n",
1562 	       esp->msg_in[2]);
1563 
1564 	esp->msg_out[0] = ABORT_TASK_SET;
1565 	esp->msg_out_len = 1;
1566 	scsi_esp_cmd(esp, ESP_CMD_SATN);
1567 }
1568 
1569 /* Analyze msgin bytes received from target so far.  Return non-zero
1570  * if there are more bytes needed to complete the message.
1571  */
1572 static int esp_msgin_process(struct esp *esp)
1573 {
1574 	u8 msg0 = esp->msg_in[0];
1575 	int len = esp->msg_in_len;
1576 
1577 	if (msg0 & 0x80) {
1578 		/* Identify */
1579 		printk("ESP: Unexpected msgin identify\n");
1580 		return 0;
1581 	}
1582 
1583 	switch (msg0) {
1584 	case EXTENDED_MESSAGE:
1585 		if (len == 1)
1586 			return 1;
1587 		if (len < esp->msg_in[1] + 2)
1588 			return 1;
1589 		esp_msgin_extended(esp);
1590 		return 0;
1591 
1592 	case IGNORE_WIDE_RESIDUE: {
1593 		struct esp_cmd_entry *ent;
1594 		struct esp_cmd_priv *spriv;
1595 		if (len == 1)
1596 			return 1;
1597 
1598 		if (esp->msg_in[1] != 1)
1599 			goto do_reject;
1600 
1601 		ent = esp->active_cmd;
1602 		spriv = ESP_CMD_PRIV(ent->cmd);
1603 
1604 		if (spriv->cur_residue == sg_dma_len(spriv->cur_sg)) {
1605 			spriv->cur_sg--;
1606 			spriv->cur_residue = 1;
1607 		} else
1608 			spriv->cur_residue++;
1609 		spriv->tot_residue++;
1610 		return 0;
1611 	}
1612 	case NOP:
1613 		return 0;
1614 	case RESTORE_POINTERS:
1615 		esp_restore_pointers(esp, esp->active_cmd);
1616 		return 0;
1617 	case SAVE_POINTERS:
1618 		esp_save_pointers(esp, esp->active_cmd);
1619 		return 0;
1620 
1621 	case COMMAND_COMPLETE:
1622 	case DISCONNECT: {
1623 		struct esp_cmd_entry *ent = esp->active_cmd;
1624 
1625 		ent->message = msg0;
1626 		esp_event(esp, ESP_EVENT_FREE_BUS);
1627 		esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
1628 		return 0;
1629 	}
1630 	case MESSAGE_REJECT:
1631 		esp_msgin_reject(esp);
1632 		return 0;
1633 
1634 	default:
1635 	do_reject:
1636 		esp->msg_out[0] = MESSAGE_REJECT;
1637 		esp->msg_out_len = 1;
1638 		scsi_esp_cmd(esp, ESP_CMD_SATN);
1639 		return 0;
1640 	}
1641 }
1642 
1643 static int esp_process_event(struct esp *esp)
1644 {
1645 	int write;
1646 
1647 again:
1648 	write = 0;
1649 	switch (esp->event) {
1650 	case ESP_EVENT_CHECK_PHASE:
1651 		switch (esp->sreg & ESP_STAT_PMASK) {
1652 		case ESP_DOP:
1653 			esp_event(esp, ESP_EVENT_DATA_OUT);
1654 			break;
1655 		case ESP_DIP:
1656 			esp_event(esp, ESP_EVENT_DATA_IN);
1657 			break;
1658 		case ESP_STATP:
1659 			esp_flush_fifo(esp);
1660 			scsi_esp_cmd(esp, ESP_CMD_ICCSEQ);
1661 			esp_event(esp, ESP_EVENT_STATUS);
1662 			esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
1663 			return 1;
1664 
1665 		case ESP_MOP:
1666 			esp_event(esp, ESP_EVENT_MSGOUT);
1667 			break;
1668 
1669 		case ESP_MIP:
1670 			esp_event(esp, ESP_EVENT_MSGIN);
1671 			break;
1672 
1673 		case ESP_CMDP:
1674 			esp_event(esp, ESP_EVENT_CMD_START);
1675 			break;
1676 
1677 		default:
1678 			printk("ESP: Unexpected phase, sreg=%02x\n",
1679 			       esp->sreg);
1680 			esp_schedule_reset(esp);
1681 			return 0;
1682 		}
1683 		goto again;
1684 		break;
1685 
1686 	case ESP_EVENT_DATA_IN:
1687 		write = 1;
1688 		/* fallthru */
1689 
1690 	case ESP_EVENT_DATA_OUT: {
1691 		struct esp_cmd_entry *ent = esp->active_cmd;
1692 		struct scsi_cmnd *cmd = ent->cmd;
1693 		dma_addr_t dma_addr = esp_cur_dma_addr(ent, cmd);
1694 		unsigned int dma_len = esp_cur_dma_len(ent, cmd);
1695 
1696 		if (esp->rev == ESP100)
1697 			scsi_esp_cmd(esp, ESP_CMD_NULL);
1698 
1699 		if (write)
1700 			ent->flags |= ESP_CMD_FLAG_WRITE;
1701 		else
1702 			ent->flags &= ~ESP_CMD_FLAG_WRITE;
1703 
1704 		dma_len = esp_dma_length_limit(esp, dma_addr, dma_len);
1705 		esp->data_dma_len = dma_len;
1706 
1707 		if (!dma_len) {
1708 			printk(KERN_ERR PFX "esp%d: DMA length is zero!\n",
1709 			       esp->host->unique_id);
1710 			printk(KERN_ERR PFX "esp%d: cur adr[%08llx] len[%08x]\n",
1711 			       esp->host->unique_id,
1712 			       (unsigned long long)esp_cur_dma_addr(ent, cmd),
1713 			       esp_cur_dma_len(ent, cmd));
1714 			esp_schedule_reset(esp);
1715 			return 0;
1716 		}
1717 
1718 		esp_log_datastart("ESP: start data addr[%08llx] len[%u] "
1719 				  "write(%d)\n",
1720 				  (unsigned long long)dma_addr, dma_len, write);
1721 
1722 		esp->ops->send_dma_cmd(esp, dma_addr, dma_len, dma_len,
1723 				       write, ESP_CMD_DMA | ESP_CMD_TI);
1724 		esp_event(esp, ESP_EVENT_DATA_DONE);
1725 		break;
1726 	}
1727 	case ESP_EVENT_DATA_DONE: {
1728 		struct esp_cmd_entry *ent = esp->active_cmd;
1729 		struct scsi_cmnd *cmd = ent->cmd;
1730 		int bytes_sent;
1731 
1732 		if (esp->ops->dma_error(esp)) {
1733 			printk("ESP: data done, DMA error, resetting\n");
1734 			esp_schedule_reset(esp);
1735 			return 0;
1736 		}
1737 
1738 		if (ent->flags & ESP_CMD_FLAG_WRITE) {
1739 			/* XXX parity errors, etc. XXX */
1740 
1741 			esp->ops->dma_drain(esp);
1742 		}
1743 		esp->ops->dma_invalidate(esp);
1744 
1745 		if (esp->ireg != ESP_INTR_BSERV) {
1746 			/* We should always see exactly a bus-service
1747 			 * interrupt at the end of a successful transfer.
1748 			 */
1749 			printk("ESP: data done, not BSERV, resetting\n");
1750 			esp_schedule_reset(esp);
1751 			return 0;
1752 		}
1753 
1754 		bytes_sent = esp_data_bytes_sent(esp, ent, cmd);
1755 
1756 		esp_log_datadone("ESP: data done flgs[%x] sent[%d]\n",
1757 				 ent->flags, bytes_sent);
1758 
1759 		if (bytes_sent < 0) {
1760 			/* XXX force sync mode for this target XXX */
1761 			esp_schedule_reset(esp);
1762 			return 0;
1763 		}
1764 
1765 		esp_advance_dma(esp, ent, cmd, bytes_sent);
1766 		esp_event(esp, ESP_EVENT_CHECK_PHASE);
1767 		goto again;
1768 		break;
1769 	}
1770 
1771 	case ESP_EVENT_STATUS: {
1772 		struct esp_cmd_entry *ent = esp->active_cmd;
1773 
1774 		if (esp->ireg & ESP_INTR_FDONE) {
1775 			ent->status = esp_read8(ESP_FDATA);
1776 			ent->message = esp_read8(ESP_FDATA);
1777 			scsi_esp_cmd(esp, ESP_CMD_MOK);
1778 		} else if (esp->ireg == ESP_INTR_BSERV) {
1779 			ent->status = esp_read8(ESP_FDATA);
1780 			ent->message = 0xff;
1781 			esp_event(esp, ESP_EVENT_MSGIN);
1782 			return 0;
1783 		}
1784 
1785 		if (ent->message != COMMAND_COMPLETE) {
1786 			printk("ESP: Unexpected message %x in status\n",
1787 			       ent->message);
1788 			esp_schedule_reset(esp);
1789 			return 0;
1790 		}
1791 
1792 		esp_event(esp, ESP_EVENT_FREE_BUS);
1793 		esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
1794 		break;
1795 	}
1796 	case ESP_EVENT_FREE_BUS: {
1797 		struct esp_cmd_entry *ent = esp->active_cmd;
1798 		struct scsi_cmnd *cmd = ent->cmd;
1799 
1800 		if (ent->message == COMMAND_COMPLETE ||
1801 		    ent->message == DISCONNECT)
1802 			scsi_esp_cmd(esp, ESP_CMD_ESEL);
1803 
1804 		if (ent->message == COMMAND_COMPLETE) {
1805 			esp_log_cmddone("ESP: Command done status[%x] "
1806 					"message[%x]\n",
1807 					ent->status, ent->message);
1808 			if (ent->status == SAM_STAT_TASK_SET_FULL)
1809 				esp_event_queue_full(esp, ent);
1810 
1811 			if (ent->status == SAM_STAT_CHECK_CONDITION &&
1812 			    !(ent->flags & ESP_CMD_FLAG_AUTOSENSE)) {
1813 				ent->flags |= ESP_CMD_FLAG_AUTOSENSE;
1814 				esp_autosense(esp, ent);
1815 			} else {
1816 				esp_cmd_is_done(esp, ent, cmd,
1817 						compose_result(ent->status,
1818 							       ent->message,
1819 							       DID_OK));
1820 			}
1821 		} else if (ent->message == DISCONNECT) {
1822 			esp_log_disconnect("ESP: Disconnecting tgt[%d] "
1823 					   "tag[%x:%x]\n",
1824 					   cmd->device->id,
1825 					   ent->tag[0], ent->tag[1]);
1826 
1827 			esp->active_cmd = NULL;
1828 			esp_maybe_execute_command(esp);
1829 		} else {
1830 			printk("ESP: Unexpected message %x in freebus\n",
1831 			       ent->message);
1832 			esp_schedule_reset(esp);
1833 			return 0;
1834 		}
1835 		if (esp->active_cmd)
1836 			esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
1837 		break;
1838 	}
1839 	case ESP_EVENT_MSGOUT: {
1840 		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
1841 
1842 		if (esp_debug & ESP_DEBUG_MSGOUT) {
1843 			int i;
1844 			printk("ESP: Sending message [ ");
1845 			for (i = 0; i < esp->msg_out_len; i++)
1846 				printk("%02x ", esp->msg_out[i]);
1847 			printk("]\n");
1848 		}
1849 
1850 		if (esp->rev == FASHME) {
1851 			int i;
1852 
1853 			/* Always use the fifo.  */
1854 			for (i = 0; i < esp->msg_out_len; i++) {
1855 				esp_write8(esp->msg_out[i], ESP_FDATA);
1856 				esp_write8(0, ESP_FDATA);
1857 			}
1858 			scsi_esp_cmd(esp, ESP_CMD_TI);
1859 		} else {
1860 			if (esp->msg_out_len == 1) {
1861 				esp_write8(esp->msg_out[0], ESP_FDATA);
1862 				scsi_esp_cmd(esp, ESP_CMD_TI);
1863 			} else {
1864 				/* Use DMA. */
1865 				memcpy(esp->command_block,
1866 				       esp->msg_out,
1867 				       esp->msg_out_len);
1868 
1869 				esp->ops->send_dma_cmd(esp,
1870 						       esp->command_block_dma,
1871 						       esp->msg_out_len,
1872 						       esp->msg_out_len,
1873 						       0,
1874 						       ESP_CMD_DMA|ESP_CMD_TI);
1875 			}
1876 		}
1877 		esp_event(esp, ESP_EVENT_MSGOUT_DONE);
1878 		break;
1879 	}
1880 	case ESP_EVENT_MSGOUT_DONE:
1881 		if (esp->rev == FASHME) {
1882 			scsi_esp_cmd(esp, ESP_CMD_FLUSH);
1883 		} else {
1884 			if (esp->msg_out_len > 1)
1885 				esp->ops->dma_invalidate(esp);
1886 		}
1887 
1888 		if (!(esp->ireg & ESP_INTR_DC)) {
1889 			if (esp->rev != FASHME)
1890 				scsi_esp_cmd(esp, ESP_CMD_NULL);
1891 		}
1892 		esp_event(esp, ESP_EVENT_CHECK_PHASE);
1893 		goto again;
1894 	case ESP_EVENT_MSGIN:
1895 		if (esp->ireg & ESP_INTR_BSERV) {
1896 			if (esp->rev == FASHME) {
1897 				if (!(esp_read8(ESP_STATUS2) &
1898 				      ESP_STAT2_FEMPTY))
1899 					scsi_esp_cmd(esp, ESP_CMD_FLUSH);
1900 			} else {
1901 				scsi_esp_cmd(esp, ESP_CMD_FLUSH);
1902 				if (esp->rev == ESP100)
1903 					scsi_esp_cmd(esp, ESP_CMD_NULL);
1904 			}
1905 			scsi_esp_cmd(esp, ESP_CMD_TI);
1906 			esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
1907 			return 1;
1908 		}
1909 		if (esp->ireg & ESP_INTR_FDONE) {
1910 			u8 val;
1911 
1912 			if (esp->rev == FASHME)
1913 				val = esp->fifo[0];
1914 			else
1915 				val = esp_read8(ESP_FDATA);
1916 			esp->msg_in[esp->msg_in_len++] = val;
1917 
1918 			esp_log_msgin("ESP: Got msgin byte %x\n", val);
1919 
1920 			if (!esp_msgin_process(esp))
1921 				esp->msg_in_len = 0;
1922 
1923 			if (esp->rev == FASHME)
1924 				scsi_esp_cmd(esp, ESP_CMD_FLUSH);
1925 
1926 			scsi_esp_cmd(esp, ESP_CMD_MOK);
1927 
1928 			if (esp->event != ESP_EVENT_FREE_BUS)
1929 				esp_event(esp, ESP_EVENT_CHECK_PHASE);
1930 		} else {
1931 			printk("ESP: MSGIN neither BSERV not FDON, resetting");
1932 			esp_schedule_reset(esp);
1933 			return 0;
1934 		}
1935 		break;
1936 	case ESP_EVENT_CMD_START:
1937 		memcpy(esp->command_block, esp->cmd_bytes_ptr,
1938 		       esp->cmd_bytes_left);
1939 		if (esp->rev == FASHME)
1940 			scsi_esp_cmd(esp, ESP_CMD_FLUSH);
1941 		esp->ops->send_dma_cmd(esp, esp->command_block_dma,
1942 				       esp->cmd_bytes_left, 16, 0,
1943 				       ESP_CMD_DMA | ESP_CMD_TI);
1944 		esp_event(esp, ESP_EVENT_CMD_DONE);
1945 		esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
1946 		break;
1947 	case ESP_EVENT_CMD_DONE:
1948 		esp->ops->dma_invalidate(esp);
1949 		if (esp->ireg & ESP_INTR_BSERV) {
1950 			esp_event(esp, ESP_EVENT_CHECK_PHASE);
1951 			goto again;
1952 		}
1953 		esp_schedule_reset(esp);
1954 		return 0;
1955 		break;
1956 
1957 	case ESP_EVENT_RESET:
1958 		scsi_esp_cmd(esp, ESP_CMD_RS);
1959 		break;
1960 
1961 	default:
1962 		printk("ESP: Unexpected event %x, resetting\n",
1963 		       esp->event);
1964 		esp_schedule_reset(esp);
1965 		return 0;
1966 		break;
1967 	}
1968 	return 1;
1969 }
1970 
1971 static void esp_reset_cleanup_one(struct esp *esp, struct esp_cmd_entry *ent)
1972 {
1973 	struct scsi_cmnd *cmd = ent->cmd;
1974 
1975 	esp_unmap_dma(esp, cmd);
1976 	esp_free_lun_tag(ent, cmd->device->hostdata);
1977 	cmd->result = DID_RESET << 16;
1978 
1979 	if (ent->flags & ESP_CMD_FLAG_AUTOSENSE) {
1980 		esp->ops->unmap_single(esp, ent->sense_dma,
1981 				       SCSI_SENSE_BUFFERSIZE, DMA_FROM_DEVICE);
1982 		ent->sense_ptr = NULL;
1983 	}
1984 
1985 	cmd->scsi_done(cmd);
1986 	list_del(&ent->list);
1987 	esp_put_ent(esp, ent);
1988 }
1989 
1990 static void esp_clear_hold(struct scsi_device *dev, void *data)
1991 {
1992 	struct esp_lun_data *lp = dev->hostdata;
1993 
1994 	BUG_ON(lp->num_tagged);
1995 	lp->hold = 0;
1996 }
1997 
1998 static void esp_reset_cleanup(struct esp *esp)
1999 {
2000 	struct esp_cmd_entry *ent, *tmp;
2001 	int i;
2002 
2003 	list_for_each_entry_safe(ent, tmp, &esp->queued_cmds, list) {
2004 		struct scsi_cmnd *cmd = ent->cmd;
2005 
2006 		list_del(&ent->list);
2007 		cmd->result = DID_RESET << 16;
2008 		cmd->scsi_done(cmd);
2009 		esp_put_ent(esp, ent);
2010 	}
2011 
2012 	list_for_each_entry_safe(ent, tmp, &esp->active_cmds, list) {
2013 		if (ent == esp->active_cmd)
2014 			esp->active_cmd = NULL;
2015 		esp_reset_cleanup_one(esp, ent);
2016 	}
2017 
2018 	BUG_ON(esp->active_cmd != NULL);
2019 
2020 	/* Force renegotiation of sync/wide transfers.  */
2021 	for (i = 0; i < ESP_MAX_TARGET; i++) {
2022 		struct esp_target_data *tp = &esp->target[i];
2023 
2024 		tp->esp_period = 0;
2025 		tp->esp_offset = 0;
2026 		tp->esp_config3 &= ~(ESP_CONFIG3_EWIDE |
2027 				     ESP_CONFIG3_FSCSI |
2028 				     ESP_CONFIG3_FAST);
2029 		tp->flags &= ~ESP_TGT_WIDE;
2030 		tp->flags |= ESP_TGT_CHECK_NEGO;
2031 
2032 		if (tp->starget)
2033 			starget_for_each_device(tp->starget, NULL,
2034 						esp_clear_hold);
2035 	}
2036 }
2037 
2038 /* Runs under host->lock */
2039 static void __esp_interrupt(struct esp *esp)
2040 {
2041 	int finish_reset, intr_done;
2042 	u8 phase;
2043 
2044 	esp->sreg = esp_read8(ESP_STATUS);
2045 
2046 	if (esp->flags & ESP_FLAG_RESETTING) {
2047 		finish_reset = 1;
2048 	} else {
2049 		if (esp_check_gross_error(esp))
2050 			return;
2051 
2052 		finish_reset = esp_check_spur_intr(esp);
2053 		if (finish_reset < 0)
2054 			return;
2055 	}
2056 
2057 	esp->ireg = esp_read8(ESP_INTRPT);
2058 
2059 	if (esp->ireg & ESP_INTR_SR)
2060 		finish_reset = 1;
2061 
2062 	if (finish_reset) {
2063 		esp_reset_cleanup(esp);
2064 		if (esp->eh_reset) {
2065 			complete(esp->eh_reset);
2066 			esp->eh_reset = NULL;
2067 		}
2068 		return;
2069 	}
2070 
2071 	phase = (esp->sreg & ESP_STAT_PMASK);
2072 	if (esp->rev == FASHME) {
2073 		if (((phase != ESP_DIP && phase != ESP_DOP) &&
2074 		     esp->select_state == ESP_SELECT_NONE &&
2075 		     esp->event != ESP_EVENT_STATUS &&
2076 		     esp->event != ESP_EVENT_DATA_DONE) ||
2077 		    (esp->ireg & ESP_INTR_RSEL)) {
2078 			esp->sreg2 = esp_read8(ESP_STATUS2);
2079 			if (!(esp->sreg2 & ESP_STAT2_FEMPTY) ||
2080 			    (esp->sreg2 & ESP_STAT2_F1BYTE))
2081 				hme_read_fifo(esp);
2082 		}
2083 	}
2084 
2085 	esp_log_intr("ESP: intr sreg[%02x] seqreg[%02x] "
2086 		     "sreg2[%02x] ireg[%02x]\n",
2087 		     esp->sreg, esp->seqreg, esp->sreg2, esp->ireg);
2088 
2089 	intr_done = 0;
2090 
2091 	if (esp->ireg & (ESP_INTR_S | ESP_INTR_SATN | ESP_INTR_IC)) {
2092 		printk("ESP: unexpected IREG %02x\n", esp->ireg);
2093 		if (esp->ireg & ESP_INTR_IC)
2094 			esp_dump_cmd_log(esp);
2095 
2096 		esp_schedule_reset(esp);
2097 	} else {
2098 		if (!(esp->ireg & ESP_INTR_RSEL)) {
2099 			/* Some combination of FDONE, BSERV, DC.  */
2100 			if (esp->select_state != ESP_SELECT_NONE)
2101 				intr_done = esp_finish_select(esp);
2102 		} else if (esp->ireg & ESP_INTR_RSEL) {
2103 			if (esp->active_cmd)
2104 				(void) esp_finish_select(esp);
2105 			intr_done = esp_reconnect(esp);
2106 		}
2107 	}
2108 	while (!intr_done)
2109 		intr_done = esp_process_event(esp);
2110 }
2111 
2112 irqreturn_t scsi_esp_intr(int irq, void *dev_id)
2113 {
2114 	struct esp *esp = dev_id;
2115 	unsigned long flags;
2116 	irqreturn_t ret;
2117 
2118 	spin_lock_irqsave(esp->host->host_lock, flags);
2119 	ret = IRQ_NONE;
2120 	if (esp->ops->irq_pending(esp)) {
2121 		ret = IRQ_HANDLED;
2122 		for (;;) {
2123 			int i;
2124 
2125 			__esp_interrupt(esp);
2126 			if (!(esp->flags & ESP_FLAG_QUICKIRQ_CHECK))
2127 				break;
2128 			esp->flags &= ~ESP_FLAG_QUICKIRQ_CHECK;
2129 
2130 			for (i = 0; i < ESP_QUICKIRQ_LIMIT; i++) {
2131 				if (esp->ops->irq_pending(esp))
2132 					break;
2133 			}
2134 			if (i == ESP_QUICKIRQ_LIMIT)
2135 				break;
2136 		}
2137 	}
2138 	spin_unlock_irqrestore(esp->host->host_lock, flags);
2139 
2140 	return ret;
2141 }
2142 EXPORT_SYMBOL(scsi_esp_intr);
2143 
2144 static void __devinit esp_get_revision(struct esp *esp)
2145 {
2146 	u8 val;
2147 
2148 	esp->config1 = (ESP_CONFIG1_PENABLE | (esp->scsi_id & 7));
2149 	esp->config2 = (ESP_CONFIG2_SCSI2ENAB | ESP_CONFIG2_REGPARITY);
2150 	esp_write8(esp->config2, ESP_CFG2);
2151 
2152 	val = esp_read8(ESP_CFG2);
2153 	val &= ~ESP_CONFIG2_MAGIC;
2154 	if (val != (ESP_CONFIG2_SCSI2ENAB | ESP_CONFIG2_REGPARITY)) {
2155 		/* If what we write to cfg2 does not come back, cfg2 is not
2156 		 * implemented, therefore this must be a plain esp100.
2157 		 */
2158 		esp->rev = ESP100;
2159 	} else {
2160 		esp->config2 = 0;
2161 		esp_set_all_config3(esp, 5);
2162 		esp->prev_cfg3 = 5;
2163 		esp_write8(esp->config2, ESP_CFG2);
2164 		esp_write8(0, ESP_CFG3);
2165 		esp_write8(esp->prev_cfg3, ESP_CFG3);
2166 
2167 		val = esp_read8(ESP_CFG3);
2168 		if (val != 5) {
2169 			/* The cfg2 register is implemented, however
2170 			 * cfg3 is not, must be esp100a.
2171 			 */
2172 			esp->rev = ESP100A;
2173 		} else {
2174 			esp_set_all_config3(esp, 0);
2175 			esp->prev_cfg3 = 0;
2176 			esp_write8(esp->prev_cfg3, ESP_CFG3);
2177 
2178 			/* All of cfg{1,2,3} implemented, must be one of
2179 			 * the fas variants, figure out which one.
2180 			 */
2181 			if (esp->cfact == 0 || esp->cfact > ESP_CCF_F5) {
2182 				esp->rev = FAST;
2183 				esp->sync_defp = SYNC_DEFP_FAST;
2184 			} else {
2185 				esp->rev = ESP236;
2186 			}
2187 			esp->config2 = 0;
2188 			esp_write8(esp->config2, ESP_CFG2);
2189 		}
2190 	}
2191 }
2192 
2193 static void __devinit esp_init_swstate(struct esp *esp)
2194 {
2195 	int i;
2196 
2197 	INIT_LIST_HEAD(&esp->queued_cmds);
2198 	INIT_LIST_HEAD(&esp->active_cmds);
2199 	INIT_LIST_HEAD(&esp->esp_cmd_pool);
2200 
2201 	/* Start with a clear state, domain validation (via ->slave_configure,
2202 	 * spi_dv_device()) will attempt to enable SYNC, WIDE, and tagged
2203 	 * commands.
2204 	 */
2205 	for (i = 0 ; i < ESP_MAX_TARGET; i++) {
2206 		esp->target[i].flags = 0;
2207 		esp->target[i].nego_goal_period = 0;
2208 		esp->target[i].nego_goal_offset = 0;
2209 		esp->target[i].nego_goal_width = 0;
2210 		esp->target[i].nego_goal_tags = 0;
2211 	}
2212 }
2213 
2214 /* This places the ESP into a known state at boot time. */
2215 static void __devinit esp_bootup_reset(struct esp *esp)
2216 {
2217 	u8 val;
2218 
2219 	/* Reset the DMA */
2220 	esp->ops->reset_dma(esp);
2221 
2222 	/* Reset the ESP */
2223 	esp_reset_esp(esp);
2224 
2225 	/* Reset the SCSI bus, but tell ESP not to generate an irq */
2226 	val = esp_read8(ESP_CFG1);
2227 	val |= ESP_CONFIG1_SRRDISAB;
2228 	esp_write8(val, ESP_CFG1);
2229 
2230 	scsi_esp_cmd(esp, ESP_CMD_RS);
2231 	udelay(400);
2232 
2233 	esp_write8(esp->config1, ESP_CFG1);
2234 
2235 	/* Eat any bitrot in the chip and we are done... */
2236 	esp_read8(ESP_INTRPT);
2237 }
2238 
2239 static void __devinit esp_set_clock_params(struct esp *esp)
2240 {
2241 	int fmhz;
2242 	u8 ccf;
2243 
2244 	/* This is getting messy but it has to be done correctly or else
2245 	 * you get weird behavior all over the place.  We are trying to
2246 	 * basically figure out three pieces of information.
2247 	 *
2248 	 * a) Clock Conversion Factor
2249 	 *
2250 	 *    This is a representation of the input crystal clock frequency
2251 	 *    going into the ESP on this machine.  Any operation whose timing
2252 	 *    is longer than 400ns depends on this value being correct.  For
2253 	 *    example, you'll get blips for arbitration/selection during high
2254 	 *    load or with multiple targets if this is not set correctly.
2255 	 *
2256 	 * b) Selection Time-Out
2257 	 *
2258 	 *    The ESP isn't very bright and will arbitrate for the bus and try
2259 	 *    to select a target forever if you let it.  This value tells the
2260 	 *    ESP when it has taken too long to negotiate and that it should
2261 	 *    interrupt the CPU so we can see what happened.  The value is
2262 	 *    computed as follows (from NCR/Symbios chip docs).
2263 	 *
2264 	 *          (Time Out Period) *  (Input Clock)
2265 	 *    STO = ----------------------------------
2266 	 *          (8192) * (Clock Conversion Factor)
2267 	 *
2268 	 *    We use a time out period of 250ms (ESP_BUS_TIMEOUT).
2269 	 *
2270 	 * c) Imperical constants for synchronous offset and transfer period
2271          *    register values
2272 	 *
2273 	 *    This entails the smallest and largest sync period we could ever
2274 	 *    handle on this ESP.
2275 	 */
2276 	fmhz = esp->cfreq;
2277 
2278 	ccf = ((fmhz / 1000000) + 4) / 5;
2279 	if (ccf == 1)
2280 		ccf = 2;
2281 
2282 	/* If we can't find anything reasonable, just assume 20MHZ.
2283 	 * This is the clock frequency of the older sun4c's where I've
2284 	 * been unable to find the clock-frequency PROM property.  All
2285 	 * other machines provide useful values it seems.
2286 	 */
2287 	if (fmhz <= 5000000 || ccf < 1 || ccf > 8) {
2288 		fmhz = 20000000;
2289 		ccf = 4;
2290 	}
2291 
2292 	esp->cfact = (ccf == 8 ? 0 : ccf);
2293 	esp->cfreq = fmhz;
2294 	esp->ccycle = ESP_MHZ_TO_CYCLE(fmhz);
2295 	esp->ctick = ESP_TICK(ccf, esp->ccycle);
2296 	esp->neg_defp = ESP_NEG_DEFP(fmhz, ccf);
2297 	esp->sync_defp = SYNC_DEFP_SLOW;
2298 }
2299 
2300 static const char *esp_chip_names[] = {
2301 	"ESP100",
2302 	"ESP100A",
2303 	"ESP236",
2304 	"FAS236",
2305 	"FAS100A",
2306 	"FAST",
2307 	"FASHME",
2308 };
2309 
2310 static struct scsi_transport_template *esp_transport_template;
2311 
2312 int __devinit scsi_esp_register(struct esp *esp, struct device *dev)
2313 {
2314 	static int instance;
2315 	int err;
2316 
2317 	esp->host->transportt = esp_transport_template;
2318 	esp->host->max_lun = ESP_MAX_LUN;
2319 	esp->host->cmd_per_lun = 2;
2320 
2321 	esp_set_clock_params(esp);
2322 
2323 	esp_get_revision(esp);
2324 
2325 	esp_init_swstate(esp);
2326 
2327 	esp_bootup_reset(esp);
2328 
2329 	printk(KERN_INFO PFX "esp%u, regs[%1p:%1p] irq[%u]\n",
2330 	       esp->host->unique_id, esp->regs, esp->dma_regs,
2331 	       esp->host->irq);
2332 	printk(KERN_INFO PFX "esp%u is a %s, %u MHz (ccf=%u), SCSI ID %u\n",
2333 	       esp->host->unique_id, esp_chip_names[esp->rev],
2334 	       esp->cfreq / 1000000, esp->cfact, esp->scsi_id);
2335 
2336 	/* Let the SCSI bus reset settle. */
2337 	ssleep(esp_bus_reset_settle);
2338 
2339 	err = scsi_add_host(esp->host, dev);
2340 	if (err)
2341 		return err;
2342 
2343 	esp->host->unique_id = instance++;
2344 
2345 	scsi_scan_host(esp->host);
2346 
2347 	return 0;
2348 }
2349 EXPORT_SYMBOL(scsi_esp_register);
2350 
2351 void __devexit scsi_esp_unregister(struct esp *esp)
2352 {
2353 	scsi_remove_host(esp->host);
2354 }
2355 EXPORT_SYMBOL(scsi_esp_unregister);
2356 
2357 static int esp_slave_alloc(struct scsi_device *dev)
2358 {
2359 	struct esp *esp = host_to_esp(dev->host);
2360 	struct esp_target_data *tp = &esp->target[dev->id];
2361 	struct esp_lun_data *lp;
2362 
2363 	lp = kzalloc(sizeof(*lp), GFP_KERNEL);
2364 	if (!lp)
2365 		return -ENOMEM;
2366 	dev->hostdata = lp;
2367 
2368 	tp->starget = dev->sdev_target;
2369 
2370 	spi_min_period(tp->starget) = esp->min_period;
2371 	spi_max_offset(tp->starget) = 15;
2372 
2373 	if (esp->flags & ESP_FLAG_WIDE_CAPABLE)
2374 		spi_max_width(tp->starget) = 1;
2375 	else
2376 		spi_max_width(tp->starget) = 0;
2377 
2378 	return 0;
2379 }
2380 
2381 static int esp_slave_configure(struct scsi_device *dev)
2382 {
2383 	struct esp *esp = host_to_esp(dev->host);
2384 	struct esp_target_data *tp = &esp->target[dev->id];
2385 	int goal_tags, queue_depth;
2386 
2387 	goal_tags = 0;
2388 
2389 	if (dev->tagged_supported) {
2390 		/* XXX make this configurable somehow XXX */
2391 		goal_tags = ESP_DEFAULT_TAGS;
2392 
2393 		if (goal_tags > ESP_MAX_TAG)
2394 			goal_tags = ESP_MAX_TAG;
2395 	}
2396 
2397 	queue_depth = goal_tags;
2398 	if (queue_depth < dev->host->cmd_per_lun)
2399 		queue_depth = dev->host->cmd_per_lun;
2400 
2401 	if (goal_tags) {
2402 		scsi_set_tag_type(dev, MSG_ORDERED_TAG);
2403 		scsi_activate_tcq(dev, queue_depth);
2404 	} else {
2405 		scsi_deactivate_tcq(dev, queue_depth);
2406 	}
2407 	tp->flags |= ESP_TGT_DISCONNECT;
2408 
2409 	if (!spi_initial_dv(dev->sdev_target))
2410 		spi_dv_device(dev);
2411 
2412 	return 0;
2413 }
2414 
2415 static void esp_slave_destroy(struct scsi_device *dev)
2416 {
2417 	struct esp_lun_data *lp = dev->hostdata;
2418 
2419 	kfree(lp);
2420 	dev->hostdata = NULL;
2421 }
2422 
2423 static int esp_eh_abort_handler(struct scsi_cmnd *cmd)
2424 {
2425 	struct esp *esp = host_to_esp(cmd->device->host);
2426 	struct esp_cmd_entry *ent, *tmp;
2427 	struct completion eh_done;
2428 	unsigned long flags;
2429 
2430 	/* XXX This helps a lot with debugging but might be a bit
2431 	 * XXX much for the final driver.
2432 	 */
2433 	spin_lock_irqsave(esp->host->host_lock, flags);
2434 	printk(KERN_ERR PFX "esp%d: Aborting command [%p:%02x]\n",
2435 	       esp->host->unique_id, cmd, cmd->cmnd[0]);
2436 	ent = esp->active_cmd;
2437 	if (ent)
2438 		printk(KERN_ERR PFX "esp%d: Current command [%p:%02x]\n",
2439 		       esp->host->unique_id, ent->cmd, ent->cmd->cmnd[0]);
2440 	list_for_each_entry(ent, &esp->queued_cmds, list) {
2441 		printk(KERN_ERR PFX "esp%d: Queued command [%p:%02x]\n",
2442 		       esp->host->unique_id, ent->cmd, ent->cmd->cmnd[0]);
2443 	}
2444 	list_for_each_entry(ent, &esp->active_cmds, list) {
2445 		printk(KERN_ERR PFX "esp%d: Active command [%p:%02x]\n",
2446 		       esp->host->unique_id, ent->cmd, ent->cmd->cmnd[0]);
2447 	}
2448 	esp_dump_cmd_log(esp);
2449 	spin_unlock_irqrestore(esp->host->host_lock, flags);
2450 
2451 	spin_lock_irqsave(esp->host->host_lock, flags);
2452 
2453 	ent = NULL;
2454 	list_for_each_entry(tmp, &esp->queued_cmds, list) {
2455 		if (tmp->cmd == cmd) {
2456 			ent = tmp;
2457 			break;
2458 		}
2459 	}
2460 
2461 	if (ent) {
2462 		/* Easiest case, we didn't even issue the command
2463 		 * yet so it is trivial to abort.
2464 		 */
2465 		list_del(&ent->list);
2466 
2467 		cmd->result = DID_ABORT << 16;
2468 		cmd->scsi_done(cmd);
2469 
2470 		esp_put_ent(esp, ent);
2471 
2472 		goto out_success;
2473 	}
2474 
2475 	init_completion(&eh_done);
2476 
2477 	ent = esp->active_cmd;
2478 	if (ent && ent->cmd == cmd) {
2479 		/* Command is the currently active command on
2480 		 * the bus.  If we already have an output message
2481 		 * pending, no dice.
2482 		 */
2483 		if (esp->msg_out_len)
2484 			goto out_failure;
2485 
2486 		/* Send out an abort, encouraging the target to
2487 		 * go to MSGOUT phase by asserting ATN.
2488 		 */
2489 		esp->msg_out[0] = ABORT_TASK_SET;
2490 		esp->msg_out_len = 1;
2491 		ent->eh_done = &eh_done;
2492 
2493 		scsi_esp_cmd(esp, ESP_CMD_SATN);
2494 	} else {
2495 		/* The command is disconnected.  This is not easy to
2496 		 * abort.  For now we fail and let the scsi error
2497 		 * handling layer go try a scsi bus reset or host
2498 		 * reset.
2499 		 *
2500 		 * What we could do is put together a scsi command
2501 		 * solely for the purpose of sending an abort message
2502 		 * to the target.  Coming up with all the code to
2503 		 * cook up scsi commands, special case them everywhere,
2504 		 * etc. is for questionable gain and it would be better
2505 		 * if the generic scsi error handling layer could do at
2506 		 * least some of that for us.
2507 		 *
2508 		 * Anyways this is an area for potential future improvement
2509 		 * in this driver.
2510 		 */
2511 		goto out_failure;
2512 	}
2513 
2514 	spin_unlock_irqrestore(esp->host->host_lock, flags);
2515 
2516 	if (!wait_for_completion_timeout(&eh_done, 5 * HZ)) {
2517 		spin_lock_irqsave(esp->host->host_lock, flags);
2518 		ent->eh_done = NULL;
2519 		spin_unlock_irqrestore(esp->host->host_lock, flags);
2520 
2521 		return FAILED;
2522 	}
2523 
2524 	return SUCCESS;
2525 
2526 out_success:
2527 	spin_unlock_irqrestore(esp->host->host_lock, flags);
2528 	return SUCCESS;
2529 
2530 out_failure:
2531 	/* XXX This might be a good location to set ESP_TGT_BROKEN
2532 	 * XXX since we know which target/lun in particular is
2533 	 * XXX causing trouble.
2534 	 */
2535 	spin_unlock_irqrestore(esp->host->host_lock, flags);
2536 	return FAILED;
2537 }
2538 
2539 static int esp_eh_bus_reset_handler(struct scsi_cmnd *cmd)
2540 {
2541 	struct esp *esp = host_to_esp(cmd->device->host);
2542 	struct completion eh_reset;
2543 	unsigned long flags;
2544 
2545 	init_completion(&eh_reset);
2546 
2547 	spin_lock_irqsave(esp->host->host_lock, flags);
2548 
2549 	esp->eh_reset = &eh_reset;
2550 
2551 	/* XXX This is too simple... We should add lots of
2552 	 * XXX checks here so that if we find that the chip is
2553 	 * XXX very wedged we return failure immediately so
2554 	 * XXX that we can perform a full chip reset.
2555 	 */
2556 	esp->flags |= ESP_FLAG_RESETTING;
2557 	scsi_esp_cmd(esp, ESP_CMD_RS);
2558 
2559 	spin_unlock_irqrestore(esp->host->host_lock, flags);
2560 
2561 	ssleep(esp_bus_reset_settle);
2562 
2563 	if (!wait_for_completion_timeout(&eh_reset, 5 * HZ)) {
2564 		spin_lock_irqsave(esp->host->host_lock, flags);
2565 		esp->eh_reset = NULL;
2566 		spin_unlock_irqrestore(esp->host->host_lock, flags);
2567 
2568 		return FAILED;
2569 	}
2570 
2571 	return SUCCESS;
2572 }
2573 
2574 /* All bets are off, reset the entire device.  */
2575 static int esp_eh_host_reset_handler(struct scsi_cmnd *cmd)
2576 {
2577 	struct esp *esp = host_to_esp(cmd->device->host);
2578 	unsigned long flags;
2579 
2580 	spin_lock_irqsave(esp->host->host_lock, flags);
2581 	esp_bootup_reset(esp);
2582 	esp_reset_cleanup(esp);
2583 	spin_unlock_irqrestore(esp->host->host_lock, flags);
2584 
2585 	ssleep(esp_bus_reset_settle);
2586 
2587 	return SUCCESS;
2588 }
2589 
2590 static const char *esp_info(struct Scsi_Host *host)
2591 {
2592 	return "esp";
2593 }
2594 
2595 struct scsi_host_template scsi_esp_template = {
2596 	.module			= THIS_MODULE,
2597 	.name			= "esp",
2598 	.info			= esp_info,
2599 	.queuecommand		= esp_queuecommand,
2600 	.slave_alloc		= esp_slave_alloc,
2601 	.slave_configure	= esp_slave_configure,
2602 	.slave_destroy		= esp_slave_destroy,
2603 	.eh_abort_handler	= esp_eh_abort_handler,
2604 	.eh_bus_reset_handler	= esp_eh_bus_reset_handler,
2605 	.eh_host_reset_handler	= esp_eh_host_reset_handler,
2606 	.can_queue		= 7,
2607 	.this_id		= 7,
2608 	.sg_tablesize		= SG_ALL,
2609 	.use_clustering		= ENABLE_CLUSTERING,
2610 	.max_sectors		= 0xffff,
2611 	.skip_settle_delay	= 1,
2612 };
2613 EXPORT_SYMBOL(scsi_esp_template);
2614 
2615 static void esp_get_signalling(struct Scsi_Host *host)
2616 {
2617 	struct esp *esp = host_to_esp(host);
2618 	enum spi_signal_type type;
2619 
2620 	if (esp->flags & ESP_FLAG_DIFFERENTIAL)
2621 		type = SPI_SIGNAL_HVD;
2622 	else
2623 		type = SPI_SIGNAL_SE;
2624 
2625 	spi_signalling(host) = type;
2626 }
2627 
2628 static void esp_set_offset(struct scsi_target *target, int offset)
2629 {
2630 	struct Scsi_Host *host = dev_to_shost(target->dev.parent);
2631 	struct esp *esp = host_to_esp(host);
2632 	struct esp_target_data *tp = &esp->target[target->id];
2633 
2634 	tp->nego_goal_offset = offset;
2635 	tp->flags |= ESP_TGT_CHECK_NEGO;
2636 }
2637 
2638 static void esp_set_period(struct scsi_target *target, int period)
2639 {
2640 	struct Scsi_Host *host = dev_to_shost(target->dev.parent);
2641 	struct esp *esp = host_to_esp(host);
2642 	struct esp_target_data *tp = &esp->target[target->id];
2643 
2644 	tp->nego_goal_period = period;
2645 	tp->flags |= ESP_TGT_CHECK_NEGO;
2646 }
2647 
2648 static void esp_set_width(struct scsi_target *target, int width)
2649 {
2650 	struct Scsi_Host *host = dev_to_shost(target->dev.parent);
2651 	struct esp *esp = host_to_esp(host);
2652 	struct esp_target_data *tp = &esp->target[target->id];
2653 
2654 	tp->nego_goal_width = (width ? 1 : 0);
2655 	tp->flags |= ESP_TGT_CHECK_NEGO;
2656 }
2657 
2658 static struct spi_function_template esp_transport_ops = {
2659 	.set_offset		= esp_set_offset,
2660 	.show_offset		= 1,
2661 	.set_period		= esp_set_period,
2662 	.show_period		= 1,
2663 	.set_width		= esp_set_width,
2664 	.show_width		= 1,
2665 	.get_signalling		= esp_get_signalling,
2666 };
2667 
2668 static int __init esp_init(void)
2669 {
2670 	BUILD_BUG_ON(sizeof(struct scsi_pointer) <
2671 		     sizeof(struct esp_cmd_priv));
2672 
2673 	esp_transport_template = spi_attach_transport(&esp_transport_ops);
2674 	if (!esp_transport_template)
2675 		return -ENODEV;
2676 
2677 	return 0;
2678 }
2679 
2680 static void __exit esp_exit(void)
2681 {
2682 	spi_release_transport(esp_transport_template);
2683 }
2684 
2685 MODULE_DESCRIPTION("ESP SCSI driver core");
2686 MODULE_AUTHOR("David S. Miller (davem@davemloft.net)");
2687 MODULE_LICENSE("GPL");
2688 MODULE_VERSION(DRV_VERSION);
2689 
2690 module_param(esp_bus_reset_settle, int, 0);
2691 MODULE_PARM_DESC(esp_bus_reset_settle,
2692 		 "ESP scsi bus reset delay in seconds");
2693 
2694 module_param(esp_debug, int, 0);
2695 MODULE_PARM_DESC(esp_debug,
2696 "ESP bitmapped debugging message enable value:\n"
2697 "	0x00000001	Log interrupt events\n"
2698 "	0x00000002	Log scsi commands\n"
2699 "	0x00000004	Log resets\n"
2700 "	0x00000008	Log message in events\n"
2701 "	0x00000010	Log message out events\n"
2702 "	0x00000020	Log command completion\n"
2703 "	0x00000040	Log disconnects\n"
2704 "	0x00000080	Log data start\n"
2705 "	0x00000100	Log data done\n"
2706 "	0x00000200	Log reconnects\n"
2707 "	0x00000400	Log auto-sense data\n"
2708 );
2709 
2710 module_init(esp_init);
2711 module_exit(esp_exit);
2712