xref: /linux/drivers/scsi/mesh.c (revision 61cb9ac66b30374c7fd8a8b2a3c4f8f432c72e36)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * SCSI low-level driver for the MESH (Macintosh Enhanced SCSI Hardware)
4  * bus adaptor found on Power Macintosh computers.
5  * We assume the MESH is connected to a DBDMA (descriptor-based DMA)
6  * controller.
7  *
8  * Paul Mackerras, August 1996.
9  * Copyright (C) 1996 Paul Mackerras.
10  *
11  * Apr. 21 2002  - BenH		Rework bus reset code for new error handler
12  *                              Add delay after initial bus reset
13  *                              Add module parameters
14  *
15  * Sep. 27 2003  - BenH		Move to new driver model, fix some write posting
16  *				issues
17  * To do:
18  * - handle aborts correctly
19  * - retry arbitration if lost (unless higher levels do this for us)
20  * - power down the chip when no device is detected
21  */
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/delay.h>
25 #include <linux/types.h>
26 #include <linux/string.h>
27 #include <linux/blkdev.h>
28 #include <linux/proc_fs.h>
29 #include <linux/stat.h>
30 #include <linux/interrupt.h>
31 #include <linux/reboot.h>
32 #include <linux/spinlock.h>
33 #include <linux/pci.h>
34 #include <linux/pgtable.h>
35 #include <asm/dbdma.h>
36 #include <asm/io.h>
37 #include <asm/prom.h>
38 #include <asm/irq.h>
39 #include <asm/hydra.h>
40 #include <asm/processor.h>
41 #include <asm/machdep.h>
42 #include <asm/pmac_feature.h>
43 #include <asm/macio.h>
44 
45 #include <scsi/scsi.h>
46 #include <scsi/scsi_cmnd.h>
47 #include <scsi/scsi_device.h>
48 #include <scsi/scsi_host.h>
49 
50 #include "mesh.h"
51 
52 #if 1
53 #undef KERN_DEBUG
54 #define KERN_DEBUG KERN_WARNING
55 #endif
56 
57 MODULE_AUTHOR("Paul Mackerras (paulus@samba.org)");
58 MODULE_DESCRIPTION("PowerMac MESH SCSI driver");
59 MODULE_LICENSE("GPL");
60 
61 static int sync_rate = CONFIG_SCSI_MESH_SYNC_RATE;
62 static int sync_targets = 0xff;
63 static int resel_targets = 0xff;
64 static int debug_targets = 0;	/* print debug for these targets */
65 static int init_reset_delay = CONFIG_SCSI_MESH_RESET_DELAY_MS;
66 
67 module_param(sync_rate, int, 0);
68 MODULE_PARM_DESC(sync_rate, "Synchronous rate (0..10, 0=async)");
69 module_param(sync_targets, int, 0);
70 MODULE_PARM_DESC(sync_targets, "Bitmask of targets allowed to set synchronous");
71 module_param(resel_targets, int, 0);
72 MODULE_PARM_DESC(resel_targets, "Bitmask of targets allowed to set disconnect");
73 module_param(debug_targets, int, 0644);
74 MODULE_PARM_DESC(debug_targets, "Bitmask of debugged targets");
75 module_param(init_reset_delay, int, 0);
76 MODULE_PARM_DESC(init_reset_delay, "Initial bus reset delay (0=no reset)");
77 
78 static int mesh_sync_period = 100;
79 static int mesh_sync_offset = 0;
80 static unsigned char use_active_neg = 0;  /* bit mask for SEQ_ACTIVE_NEG if used */
81 
82 #define ALLOW_SYNC(tgt)		((sync_targets >> (tgt)) & 1)
83 #define ALLOW_RESEL(tgt)	((resel_targets >> (tgt)) & 1)
84 #define ALLOW_DEBUG(tgt)	((debug_targets >> (tgt)) & 1)
85 #define DEBUG_TARGET(cmd)	((cmd) && ALLOW_DEBUG((cmd)->device->id))
86 
87 #undef MESH_DBG
88 #define N_DBG_LOG	50
89 #define N_DBG_SLOG	20
90 #define NUM_DBG_EVENTS	13
91 #undef	DBG_USE_TB		/* bombs on 601 */
92 
93 struct dbglog {
94 	char	*fmt;
95 	u32	tb;
96 	u8	phase;
97 	u8	bs0;
98 	u8	bs1;
99 	u8	tgt;
100 	int	d;
101 };
102 
103 enum mesh_phase {
104 	idle,
105 	arbitrating,
106 	selecting,
107 	commanding,
108 	dataing,
109 	statusing,
110 	busfreeing,
111 	disconnecting,
112 	reselecting,
113 	sleeping
114 };
115 
116 enum msg_phase {
117 	msg_none,
118 	msg_out,
119 	msg_out_xxx,
120 	msg_out_last,
121 	msg_in,
122 	msg_in_bad,
123 };
124 
125 enum sdtr_phase {
126 	do_sdtr,
127 	sdtr_sent,
128 	sdtr_done
129 };
130 
131 struct mesh_target {
132 	enum sdtr_phase sdtr_state;
133 	int	sync_params;
134 	int	data_goes_out;		/* guess as to data direction */
135 	struct scsi_cmnd *current_req;
136 	u32	saved_ptr;
137 #ifdef MESH_DBG
138 	int	log_ix;
139 	int	n_log;
140 	struct dbglog log[N_DBG_LOG];
141 #endif
142 };
143 
144 struct mesh_state {
145 	volatile struct	mesh_regs __iomem *mesh;
146 	int	meshintr;
147 	volatile struct	dbdma_regs __iomem *dma;
148 	int	dmaintr;
149 	struct	Scsi_Host *host;
150 	struct	mesh_state *next;
151 	struct scsi_cmnd *request_q;
152 	struct scsi_cmnd *request_qtail;
153 	enum mesh_phase phase;		/* what we're currently trying to do */
154 	enum msg_phase msgphase;
155 	int	conn_tgt;		/* target we're connected to */
156 	struct scsi_cmnd *current_req;		/* req we're currently working on */
157 	int	data_ptr;
158 	int	dma_started;
159 	int	dma_count;
160 	int	stat;
161 	int	aborting;
162 	int	expect_reply;
163 	int	n_msgin;
164 	u8	msgin[16];
165 	int	n_msgout;
166 	int	last_n_msgout;
167 	u8	msgout[16];
168 	struct dbdma_cmd *dma_cmds;	/* space for dbdma commands, aligned */
169 	dma_addr_t dma_cmd_bus;
170 	void	*dma_cmd_space;
171 	int	dma_cmd_size;
172 	int	clk_freq;
173 	struct mesh_target tgts[8];
174 	struct macio_dev *mdev;
175 	struct pci_dev* pdev;
176 #ifdef MESH_DBG
177 	int	log_ix;
178 	int	n_log;
179 	struct dbglog log[N_DBG_SLOG];
180 #endif
181 };
182 
183 /*
184  * Driver is too messy, we need a few prototypes...
185  */
186 static void mesh_done(struct mesh_state *ms, int start_next);
187 static void mesh_interrupt(struct mesh_state *ms);
188 static void cmd_complete(struct mesh_state *ms);
189 static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd);
190 static void halt_dma(struct mesh_state *ms);
191 static void phase_mismatch(struct mesh_state *ms);
192 
193 
194 /*
195  * Some debugging & logging routines
196  */
197 
198 #ifdef MESH_DBG
199 
200 static inline u32 readtb(void)
201 {
202 	u32 tb;
203 
204 #ifdef DBG_USE_TB
205 	/* Beware: if you enable this, it will crash on 601s. */
206 	asm ("mftb %0" : "=r" (tb) : );
207 #else
208 	tb = 0;
209 #endif
210 	return tb;
211 }
212 
213 static void dlog(struct mesh_state *ms, char *fmt, int a)
214 {
215 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
216 	struct dbglog *tlp, *slp;
217 
218 	tlp = &tp->log[tp->log_ix];
219 	slp = &ms->log[ms->log_ix];
220 	tlp->fmt = fmt;
221 	tlp->tb = readtb();
222 	tlp->phase = (ms->msgphase << 4) + ms->phase;
223 	tlp->bs0 = ms->mesh->bus_status0;
224 	tlp->bs1 = ms->mesh->bus_status1;
225 	tlp->tgt = ms->conn_tgt;
226 	tlp->d = a;
227 	*slp = *tlp;
228 	if (++tp->log_ix >= N_DBG_LOG)
229 		tp->log_ix = 0;
230 	if (tp->n_log < N_DBG_LOG)
231 		++tp->n_log;
232 	if (++ms->log_ix >= N_DBG_SLOG)
233 		ms->log_ix = 0;
234 	if (ms->n_log < N_DBG_SLOG)
235 		++ms->n_log;
236 }
237 
238 static void dumplog(struct mesh_state *ms, int t)
239 {
240 	struct mesh_target *tp = &ms->tgts[t];
241 	struct dbglog *lp;
242 	int i;
243 
244 	if (tp->n_log == 0)
245 		return;
246 	i = tp->log_ix - tp->n_log;
247 	if (i < 0)
248 		i += N_DBG_LOG;
249 	tp->n_log = 0;
250 	do {
251 		lp = &tp->log[i];
252 		printk(KERN_DEBUG "mesh log %d: bs=%.2x%.2x ph=%.2x ",
253 		       t, lp->bs1, lp->bs0, lp->phase);
254 #ifdef DBG_USE_TB
255 		printk("tb=%10u ", lp->tb);
256 #endif
257 		printk(lp->fmt, lp->d);
258 		printk("\n");
259 		if (++i >= N_DBG_LOG)
260 			i = 0;
261 	} while (i != tp->log_ix);
262 }
263 
264 static void dumpslog(struct mesh_state *ms)
265 {
266 	struct dbglog *lp;
267 	int i;
268 
269 	if (ms->n_log == 0)
270 		return;
271 	i = ms->log_ix - ms->n_log;
272 	if (i < 0)
273 		i += N_DBG_SLOG;
274 	ms->n_log = 0;
275 	do {
276 		lp = &ms->log[i];
277 		printk(KERN_DEBUG "mesh log: bs=%.2x%.2x ph=%.2x t%d ",
278 		       lp->bs1, lp->bs0, lp->phase, lp->tgt);
279 #ifdef DBG_USE_TB
280 		printk("tb=%10u ", lp->tb);
281 #endif
282 		printk(lp->fmt, lp->d);
283 		printk("\n");
284 		if (++i >= N_DBG_SLOG)
285 			i = 0;
286 	} while (i != ms->log_ix);
287 }
288 
289 #else
290 
291 static inline void dlog(struct mesh_state *ms, char *fmt, int a)
292 {}
293 static inline void dumplog(struct mesh_state *ms, int tgt)
294 {}
295 static inline void dumpslog(struct mesh_state *ms)
296 {}
297 
298 #endif /* MESH_DBG */
299 
300 #define MKWORD(a, b, c, d)	(((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
301 
302 static void
303 mesh_dump_regs(struct mesh_state *ms)
304 {
305 	volatile struct mesh_regs __iomem *mr = ms->mesh;
306 	volatile struct dbdma_regs __iomem *md = ms->dma;
307 	int t;
308 	struct mesh_target *tp;
309 
310 	printk(KERN_DEBUG "mesh: state at %p, regs at %p, dma at %p\n",
311 	       ms, mr, md);
312 	printk(KERN_DEBUG "    ct=%4x seq=%2x bs=%4x fc=%2x "
313 	       "exc=%2x err=%2x im=%2x int=%2x sp=%2x\n",
314 	       (mr->count_hi << 8) + mr->count_lo, mr->sequence,
315 	       (mr->bus_status1 << 8) + mr->bus_status0, mr->fifo_count,
316 	       mr->exception, mr->error, mr->intr_mask, mr->interrupt,
317 	       mr->sync_params);
318 	while(in_8(&mr->fifo_count))
319 		printk(KERN_DEBUG " fifo data=%.2x\n",in_8(&mr->fifo));
320 	printk(KERN_DEBUG "    dma stat=%x cmdptr=%x\n",
321 	       in_le32(&md->status), in_le32(&md->cmdptr));
322 	printk(KERN_DEBUG "    phase=%d msgphase=%d conn_tgt=%d data_ptr=%d\n",
323 	       ms->phase, ms->msgphase, ms->conn_tgt, ms->data_ptr);
324 	printk(KERN_DEBUG "    dma_st=%d dma_ct=%d n_msgout=%d\n",
325 	       ms->dma_started, ms->dma_count, ms->n_msgout);
326 	for (t = 0; t < 8; ++t) {
327 		tp = &ms->tgts[t];
328 		if (tp->current_req == NULL)
329 			continue;
330 		printk(KERN_DEBUG "    target %d: req=%p goes_out=%d saved_ptr=%d\n",
331 		       t, tp->current_req, tp->data_goes_out, tp->saved_ptr);
332 	}
333 }
334 
335 
336 /*
337  * Flush write buffers on the bus path to the mesh
338  */
339 static inline void mesh_flush_io(volatile struct mesh_regs __iomem *mr)
340 {
341 	(void)in_8(&mr->mesh_id);
342 }
343 
344 
345 /*
346  * Complete a SCSI command
347  */
348 static void mesh_completed(struct mesh_state *ms, struct scsi_cmnd *cmd)
349 {
350 	(*cmd->scsi_done)(cmd);
351 }
352 
353 
354 /* Called with  meshinterrupt disabled, initialize the chipset
355  * and eventually do the initial bus reset. The lock must not be
356  * held since we can schedule.
357  */
358 static void mesh_init(struct mesh_state *ms)
359 {
360 	volatile struct mesh_regs __iomem *mr = ms->mesh;
361 	volatile struct dbdma_regs __iomem *md = ms->dma;
362 
363 	mesh_flush_io(mr);
364 	udelay(100);
365 
366 	/* Reset controller */
367 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
368 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
369 	out_8(&mr->error, 0xff);	/* clear all error bits */
370 	out_8(&mr->sequence, SEQ_RESETMESH);
371 	mesh_flush_io(mr);
372 	udelay(10);
373 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
374 	out_8(&mr->source_id, ms->host->this_id);
375 	out_8(&mr->sel_timeout, 25);	/* 250ms */
376 	out_8(&mr->sync_params, ASYNC_PARAMS);
377 
378 	if (init_reset_delay) {
379 		printk(KERN_INFO "mesh: performing initial bus reset...\n");
380 
381 		/* Reset bus */
382 		out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
383 		mesh_flush_io(mr);
384 		udelay(30);			/* leave it on for >= 25us */
385 		out_8(&mr->bus_status1, 0);	/* negate RST */
386 		mesh_flush_io(mr);
387 
388 		/* Wait for bus to come back */
389 		msleep(init_reset_delay);
390 	}
391 
392 	/* Reconfigure controller */
393 	out_8(&mr->interrupt, 0xff);	/* clear all interrupt bits */
394 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
395 	mesh_flush_io(mr);
396 	udelay(1);
397 	out_8(&mr->sync_params, ASYNC_PARAMS);
398 	out_8(&mr->sequence, SEQ_ENBRESEL);
399 
400 	ms->phase = idle;
401 	ms->msgphase = msg_none;
402 }
403 
404 
405 static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
406 {
407 	volatile struct mesh_regs __iomem *mr = ms->mesh;
408 	int t, id;
409 
410 	id = cmd->device->id;
411 	ms->current_req = cmd;
412 	ms->tgts[id].data_goes_out = cmd->sc_data_direction == DMA_TO_DEVICE;
413 	ms->tgts[id].current_req = cmd;
414 
415 #if 1
416 	if (DEBUG_TARGET(cmd)) {
417 		int i;
418 		printk(KERN_DEBUG "mesh_start: %p tgt=%d cmd=", cmd, id);
419 		for (i = 0; i < cmd->cmd_len; ++i)
420 			printk(" %x", cmd->cmnd[i]);
421 		printk(" use_sg=%d buffer=%p bufflen=%u\n",
422 		       scsi_sg_count(cmd), scsi_sglist(cmd), scsi_bufflen(cmd));
423 	}
424 #endif
425 	if (ms->dma_started)
426 		panic("mesh: double DMA start !\n");
427 
428 	ms->phase = arbitrating;
429 	ms->msgphase = msg_none;
430 	ms->data_ptr = 0;
431 	ms->dma_started = 0;
432 	ms->n_msgout = 0;
433 	ms->last_n_msgout = 0;
434 	ms->expect_reply = 0;
435 	ms->conn_tgt = id;
436 	ms->tgts[id].saved_ptr = 0;
437 	ms->stat = DID_OK;
438 	ms->aborting = 0;
439 #ifdef MESH_DBG
440 	ms->tgts[id].n_log = 0;
441 	dlog(ms, "start cmd=%x", (int) cmd);
442 #endif
443 
444 	/* Off we go */
445 	dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
446 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
447 	out_8(&mr->interrupt, INT_CMDDONE);
448 	out_8(&mr->sequence, SEQ_ENBRESEL);
449 	mesh_flush_io(mr);
450 	udelay(1);
451 
452 	if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
453 		/*
454 		 * Some other device has the bus or is arbitrating for it -
455 		 * probably a target which is about to reselect us.
456 		 */
457 		dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
458 		     MKWORD(mr->interrupt, mr->exception,
459 			    mr->error, mr->fifo_count));
460 		for (t = 100; t > 0; --t) {
461 			if ((in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) == 0)
462 				break;
463 			if (in_8(&mr->interrupt) != 0) {
464 				dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
465 				     MKWORD(mr->interrupt, mr->exception,
466 					    mr->error, mr->fifo_count));
467 				mesh_interrupt(ms);
468 				if (ms->phase != arbitrating)
469 					return;
470 			}
471 			udelay(1);
472 		}
473 		if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
474 			/* XXX should try again in a little while */
475 			ms->stat = DID_BUS_BUSY;
476 			ms->phase = idle;
477 			mesh_done(ms, 0);
478 			return;
479 		}
480 	}
481 
482 	/*
483 	 * Apparently the mesh has a bug where it will assert both its
484 	 * own bit and the target's bit on the bus during arbitration.
485 	 */
486 	out_8(&mr->dest_id, mr->source_id);
487 
488 	/*
489 	 * There appears to be a race with reselection sometimes,
490 	 * where a target reselects us just as we issue the
491 	 * arbitrate command.  It seems that then the arbitrate
492 	 * command just hangs waiting for the bus to be free
493 	 * without giving us a reselection exception.
494 	 * The only way I have found to get it to respond correctly
495 	 * is this: disable reselection before issuing the arbitrate
496 	 * command, then after issuing it, if it looks like a target
497 	 * is trying to reselect us, reset the mesh and then enable
498 	 * reselection.
499 	 */
500 	out_8(&mr->sequence, SEQ_DISRESEL);
501 	if (in_8(&mr->interrupt) != 0) {
502 		dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
503 		     MKWORD(mr->interrupt, mr->exception,
504 			    mr->error, mr->fifo_count));
505 		mesh_interrupt(ms);
506 		if (ms->phase != arbitrating)
507 			return;
508 		dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
509 		     MKWORD(mr->interrupt, mr->exception,
510 			    mr->error, mr->fifo_count));
511 	}
512 
513 	out_8(&mr->sequence, SEQ_ARBITRATE);
514 
515 	for (t = 230; t > 0; --t) {
516 		if (in_8(&mr->interrupt) != 0)
517 			break;
518 		udelay(1);
519 	}
520 	dlog(ms, "after arb, intr/exc/err/fc=%.8x",
521 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
522 	if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
523 	    && (in_8(&mr->bus_status0) & BS0_IO)) {
524 		/* looks like a reselection - try resetting the mesh */
525 		dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
526 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
527 		out_8(&mr->sequence, SEQ_RESETMESH);
528 		mesh_flush_io(mr);
529 		udelay(10);
530 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
531 		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
532 		out_8(&mr->sequence, SEQ_ENBRESEL);
533 		mesh_flush_io(mr);
534 		for (t = 10; t > 0 && in_8(&mr->interrupt) == 0; --t)
535 			udelay(1);
536 		dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
537 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
538 #ifndef MESH_MULTIPLE_HOSTS
539 		if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
540 		    && (in_8(&mr->bus_status0) & BS0_IO)) {
541 			printk(KERN_ERR "mesh: controller not responding"
542 			       " to reselection!\n");
543 			/*
544 			 * If this is a target reselecting us, and the
545 			 * mesh isn't responding, the higher levels of
546 			 * the scsi code will eventually time out and
547 			 * reset the bus.
548 			 */
549 		}
550 #endif
551 	}
552 }
553 
554 /*
555  * Start the next command for a MESH.
556  * Should be called with interrupts disabled.
557  */
558 static void mesh_start(struct mesh_state *ms)
559 {
560 	struct scsi_cmnd *cmd, *prev, *next;
561 
562 	if (ms->phase != idle || ms->current_req != NULL) {
563 		printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
564 		       ms->phase, ms);
565 		return;
566 	}
567 
568 	while (ms->phase == idle) {
569 		prev = NULL;
570 		for (cmd = ms->request_q; ; cmd = (struct scsi_cmnd *) cmd->host_scribble) {
571 			if (cmd == NULL)
572 				return;
573 			if (ms->tgts[cmd->device->id].current_req == NULL)
574 				break;
575 			prev = cmd;
576 		}
577 		next = (struct scsi_cmnd *) cmd->host_scribble;
578 		if (prev == NULL)
579 			ms->request_q = next;
580 		else
581 			prev->host_scribble = (void *) next;
582 		if (next == NULL)
583 			ms->request_qtail = prev;
584 
585 		mesh_start_cmd(ms, cmd);
586 	}
587 }
588 
589 static void mesh_done(struct mesh_state *ms, int start_next)
590 {
591 	struct scsi_cmnd *cmd;
592 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
593 
594 	cmd = ms->current_req;
595 	ms->current_req = NULL;
596 	tp->current_req = NULL;
597 	if (cmd) {
598 		set_host_byte(cmd, ms->stat);
599 		set_status_byte(cmd, cmd->SCp.Status);
600 		if (ms->stat == DID_OK)
601 			scsi_msg_to_host_byte(cmd, cmd->SCp.Message);
602 		if (DEBUG_TARGET(cmd)) {
603 			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
604 			       cmd->result, ms->data_ptr, scsi_bufflen(cmd));
605 #if 0
606 			/* needs to use sg? */
607 			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
608 			    && cmd->request_buffer != 0) {
609 				unsigned char *b = cmd->request_buffer;
610 				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
611 				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
612 			}
613 #endif
614 		}
615 		cmd->SCp.this_residual -= ms->data_ptr;
616 		mesh_completed(ms, cmd);
617 	}
618 	if (start_next) {
619 		out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
620 		mesh_flush_io(ms->mesh);
621 		udelay(1);
622 		ms->phase = idle;
623 		mesh_start(ms);
624 	}
625 }
626 
627 static inline void add_sdtr_msg(struct mesh_state *ms)
628 {
629 	int i = ms->n_msgout;
630 
631 	ms->msgout[i] = EXTENDED_MESSAGE;
632 	ms->msgout[i+1] = 3;
633 	ms->msgout[i+2] = EXTENDED_SDTR;
634 	ms->msgout[i+3] = mesh_sync_period/4;
635 	ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
636 	ms->n_msgout = i + 5;
637 }
638 
639 static void set_sdtr(struct mesh_state *ms, int period, int offset)
640 {
641 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
642 	volatile struct mesh_regs __iomem *mr = ms->mesh;
643 	int v, tr;
644 
645 	tp->sdtr_state = sdtr_done;
646 	if (offset == 0) {
647 		/* asynchronous */
648 		if (SYNC_OFF(tp->sync_params))
649 			printk(KERN_INFO "mesh: target %d now asynchronous\n",
650 			       ms->conn_tgt);
651 		tp->sync_params = ASYNC_PARAMS;
652 		out_8(&mr->sync_params, ASYNC_PARAMS);
653 		return;
654 	}
655 	/*
656 	 * We need to compute ceil(clk_freq * period / 500e6) - 2
657 	 * without incurring overflow.
658 	 */
659 	v = (ms->clk_freq / 5000) * period;
660 	if (v <= 250000) {
661 		/* special case: sync_period == 5 * clk_period */
662 		v = 0;
663 		/* units of tr are 100kB/s */
664 		tr = (ms->clk_freq + 250000) / 500000;
665 	} else {
666 		/* sync_period == (v + 2) * 2 * clk_period */
667 		v = (v + 99999) / 100000 - 2;
668 		if (v > 15)
669 			v = 15;	/* oops */
670 		tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
671 	}
672 	if (offset > 15)
673 		offset = 15;	/* can't happen */
674 	tp->sync_params = SYNC_PARAMS(offset, v);
675 	out_8(&mr->sync_params, tp->sync_params);
676 	printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
677 	       ms->conn_tgt, tr/10, tr%10);
678 }
679 
680 static void start_phase(struct mesh_state *ms)
681 {
682 	int i, seq, nb;
683 	volatile struct mesh_regs __iomem *mr = ms->mesh;
684 	volatile struct dbdma_regs __iomem *md = ms->dma;
685 	struct scsi_cmnd *cmd = ms->current_req;
686 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
687 
688 	dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
689 	     MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
690 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
691 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
692 	switch (ms->msgphase) {
693 	case msg_none:
694 		break;
695 
696 	case msg_in:
697 		out_8(&mr->count_hi, 0);
698 		out_8(&mr->count_lo, 1);
699 		out_8(&mr->sequence, SEQ_MSGIN + seq);
700 		ms->n_msgin = 0;
701 		return;
702 
703 	case msg_out:
704 		/*
705 		 * To make sure ATN drops before we assert ACK for
706 		 * the last byte of the message, we have to do the
707 		 * last byte specially.
708 		 */
709 		if (ms->n_msgout <= 0) {
710 			printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
711 			       ms->n_msgout);
712 			mesh_dump_regs(ms);
713 			ms->msgphase = msg_none;
714 			break;
715 		}
716 		if (ALLOW_DEBUG(ms->conn_tgt)) {
717 			printk(KERN_DEBUG "mesh: sending %d msg bytes:",
718 			       ms->n_msgout);
719 			for (i = 0; i < ms->n_msgout; ++i)
720 				printk(" %x", ms->msgout[i]);
721 			printk("\n");
722 		}
723 		dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
724 						ms->msgout[1], ms->msgout[2]));
725 		out_8(&mr->count_hi, 0);
726 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
727 		mesh_flush_io(mr);
728 		udelay(1);
729 		/*
730 		 * If ATN is not already asserted, we assert it, then
731 		 * issue a SEQ_MSGOUT to get the mesh to drop ACK.
732 		 */
733 		if ((in_8(&mr->bus_status0) & BS0_ATN) == 0) {
734 			dlog(ms, "bus0 was %.2x explicitly asserting ATN", mr->bus_status0);
735 			out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
736 			mesh_flush_io(mr);
737 			udelay(1);
738 			out_8(&mr->count_lo, 1);
739 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
740 			out_8(&mr->bus_status0, 0); /* release explicit ATN */
741 			dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
742 		}
743 		if (ms->n_msgout == 1) {
744 			/*
745 			 * We can't issue the SEQ_MSGOUT without ATN
746 			 * until the target has asserted REQ.  The logic
747 			 * in cmd_complete handles both situations:
748 			 * REQ already asserted or not.
749 			 */
750 			cmd_complete(ms);
751 		} else {
752 			out_8(&mr->count_lo, ms->n_msgout - 1);
753 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
754 			for (i = 0; i < ms->n_msgout - 1; ++i)
755 				out_8(&mr->fifo, ms->msgout[i]);
756 		}
757 		return;
758 
759 	default:
760 		printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
761 		       ms->msgphase);
762 	}
763 
764 	switch (ms->phase) {
765 	case selecting:
766 		out_8(&mr->dest_id, ms->conn_tgt);
767 		out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
768 		break;
769 	case commanding:
770 		out_8(&mr->sync_params, tp->sync_params);
771 		out_8(&mr->count_hi, 0);
772 		if (cmd) {
773 			out_8(&mr->count_lo, cmd->cmd_len);
774 			out_8(&mr->sequence, SEQ_COMMAND + seq);
775 			for (i = 0; i < cmd->cmd_len; ++i)
776 				out_8(&mr->fifo, cmd->cmnd[i]);
777 		} else {
778 			out_8(&mr->count_lo, 6);
779 			out_8(&mr->sequence, SEQ_COMMAND + seq);
780 			for (i = 0; i < 6; ++i)
781 				out_8(&mr->fifo, 0);
782 		}
783 		break;
784 	case dataing:
785 		/* transfer data, if any */
786 		if (!ms->dma_started) {
787 			set_dma_cmds(ms, cmd);
788 			out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
789 			out_le32(&md->control, (RUN << 16) | RUN);
790 			ms->dma_started = 1;
791 		}
792 		nb = ms->dma_count;
793 		if (nb > 0xfff0)
794 			nb = 0xfff0;
795 		ms->dma_count -= nb;
796 		ms->data_ptr += nb;
797 		out_8(&mr->count_lo, nb);
798 		out_8(&mr->count_hi, nb >> 8);
799 		out_8(&mr->sequence, (tp->data_goes_out?
800 				SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
801 		break;
802 	case statusing:
803 		out_8(&mr->count_hi, 0);
804 		out_8(&mr->count_lo, 1);
805 		out_8(&mr->sequence, SEQ_STATUS + seq);
806 		break;
807 	case busfreeing:
808 	case disconnecting:
809 		out_8(&mr->sequence, SEQ_ENBRESEL);
810 		mesh_flush_io(mr);
811 		udelay(1);
812 		dlog(ms, "enbresel intr/exc/err/fc=%.8x",
813 		     MKWORD(mr->interrupt, mr->exception, mr->error,
814 			    mr->fifo_count));
815 		out_8(&mr->sequence, SEQ_BUSFREE);
816 		break;
817 	default:
818 		printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
819 		       ms->phase);
820 		dumpslog(ms);
821 	}
822 
823 }
824 
825 static inline void get_msgin(struct mesh_state *ms)
826 {
827 	volatile struct mesh_regs __iomem *mr = ms->mesh;
828 	int i, n;
829 
830 	n = mr->fifo_count;
831 	if (n != 0) {
832 		i = ms->n_msgin;
833 		ms->n_msgin = i + n;
834 		for (; n > 0; --n)
835 			ms->msgin[i++] = in_8(&mr->fifo);
836 	}
837 }
838 
839 static inline int msgin_length(struct mesh_state *ms)
840 {
841 	int b, n;
842 
843 	n = 1;
844 	if (ms->n_msgin > 0) {
845 		b = ms->msgin[0];
846 		if (b == 1) {
847 			/* extended message */
848 			n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
849 		} else if (0x20 <= b && b <= 0x2f) {
850 			/* 2-byte message */
851 			n = 2;
852 		}
853 	}
854 	return n;
855 }
856 
857 static void reselected(struct mesh_state *ms)
858 {
859 	volatile struct mesh_regs __iomem *mr = ms->mesh;
860 	struct scsi_cmnd *cmd;
861 	struct mesh_target *tp;
862 	int b, t, prev;
863 
864 	switch (ms->phase) {
865 	case idle:
866 		break;
867 	case arbitrating:
868 		if ((cmd = ms->current_req) != NULL) {
869 			/* put the command back on the queue */
870 			cmd->host_scribble = (void *) ms->request_q;
871 			if (ms->request_q == NULL)
872 				ms->request_qtail = cmd;
873 			ms->request_q = cmd;
874 			tp = &ms->tgts[cmd->device->id];
875 			tp->current_req = NULL;
876 		}
877 		break;
878 	case busfreeing:
879 		ms->phase = reselecting;
880 		mesh_done(ms, 0);
881 		break;
882 	case disconnecting:
883 		break;
884 	default:
885 		printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
886 		       ms->msgphase, ms->phase, ms->conn_tgt);
887 		dumplog(ms, ms->conn_tgt);
888 		dumpslog(ms);
889 	}
890 
891 	if (ms->dma_started) {
892 		printk(KERN_ERR "mesh: reselected with DMA started !\n");
893 		halt_dma(ms);
894 	}
895 	ms->current_req = NULL;
896 	ms->phase = dataing;
897 	ms->msgphase = msg_in;
898 	ms->n_msgout = 0;
899 	ms->last_n_msgout = 0;
900 	prev = ms->conn_tgt;
901 
902 	/*
903 	 * We seem to get abortive reselections sometimes.
904 	 */
905 	while ((in_8(&mr->bus_status1) & BS1_BSY) == 0) {
906 		static int mesh_aborted_resels;
907 		mesh_aborted_resels++;
908 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
909 		mesh_flush_io(mr);
910 		udelay(1);
911 		out_8(&mr->sequence, SEQ_ENBRESEL);
912 		mesh_flush_io(mr);
913 		udelay(5);
914 		dlog(ms, "extra resel err/exc/fc = %.6x",
915 		     MKWORD(0, mr->error, mr->exception, mr->fifo_count));
916 	}
917 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
918        	mesh_flush_io(mr);
919 	udelay(1);
920 	out_8(&mr->sequence, SEQ_ENBRESEL);
921        	mesh_flush_io(mr);
922 	udelay(1);
923 	out_8(&mr->sync_params, ASYNC_PARAMS);
924 
925 	/*
926 	 * Find out who reselected us.
927 	 */
928 	if (in_8(&mr->fifo_count) == 0) {
929 		printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
930 		ms->conn_tgt = ms->host->this_id;
931 		goto bogus;
932 	}
933 	/* get the last byte in the fifo */
934 	do {
935 		b = in_8(&mr->fifo);
936 		dlog(ms, "reseldata %x", b);
937 	} while (in_8(&mr->fifo_count));
938 	for (t = 0; t < 8; ++t)
939 		if ((b & (1 << t)) != 0 && t != ms->host->this_id)
940 			break;
941 	if (b != (1 << t) + (1 << ms->host->this_id)) {
942 		printk(KERN_ERR "mesh: bad reselection data %x\n", b);
943 		ms->conn_tgt = ms->host->this_id;
944 		goto bogus;
945 	}
946 
947 
948 	/*
949 	 * Set up to continue with that target's transfer.
950 	 */
951 	ms->conn_tgt = t;
952 	tp = &ms->tgts[t];
953 	out_8(&mr->sync_params, tp->sync_params);
954 	if (ALLOW_DEBUG(t)) {
955 		printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
956 		printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
957 		       tp->saved_ptr, tp->data_goes_out, tp->current_req);
958 	}
959 	ms->current_req = tp->current_req;
960 	if (tp->current_req == NULL) {
961 		printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
962 		goto bogus;
963 	}
964 	ms->data_ptr = tp->saved_ptr;
965 	dlog(ms, "resel prev tgt=%d", prev);
966 	dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
967 	start_phase(ms);
968 	return;
969 
970 bogus:
971 	dumplog(ms, ms->conn_tgt);
972 	dumpslog(ms);
973 	ms->data_ptr = 0;
974 	ms->aborting = 1;
975 	start_phase(ms);
976 }
977 
978 static void do_abort(struct mesh_state *ms)
979 {
980 	ms->msgout[0] = ABORT;
981 	ms->n_msgout = 1;
982 	ms->aborting = 1;
983 	ms->stat = DID_ABORT;
984 	dlog(ms, "abort", 0);
985 }
986 
987 static void handle_reset(struct mesh_state *ms)
988 {
989 	int tgt;
990 	struct mesh_target *tp;
991 	struct scsi_cmnd *cmd;
992 	volatile struct mesh_regs __iomem *mr = ms->mesh;
993 
994 	for (tgt = 0; tgt < 8; ++tgt) {
995 		tp = &ms->tgts[tgt];
996 		if ((cmd = tp->current_req) != NULL) {
997 			set_host_byte(cmd, DID_RESET);
998 			tp->current_req = NULL;
999 			mesh_completed(ms, cmd);
1000 		}
1001 		ms->tgts[tgt].sdtr_state = do_sdtr;
1002 		ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1003 	}
1004 	ms->current_req = NULL;
1005 	while ((cmd = ms->request_q) != NULL) {
1006 		ms->request_q = (struct scsi_cmnd *) cmd->host_scribble;
1007 		set_host_byte(cmd, DID_RESET);
1008 		mesh_completed(ms, cmd);
1009 	}
1010 	ms->phase = idle;
1011 	ms->msgphase = msg_none;
1012 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1013 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
1014        	mesh_flush_io(mr);
1015 	udelay(1);
1016 	out_8(&mr->sync_params, ASYNC_PARAMS);
1017 	out_8(&mr->sequence, SEQ_ENBRESEL);
1018 }
1019 
1020 static irqreturn_t do_mesh_interrupt(int irq, void *dev_id)
1021 {
1022 	unsigned long flags;
1023 	struct mesh_state *ms = dev_id;
1024 	struct Scsi_Host *dev = ms->host;
1025 
1026 	spin_lock_irqsave(dev->host_lock, flags);
1027 	mesh_interrupt(ms);
1028 	spin_unlock_irqrestore(dev->host_lock, flags);
1029 	return IRQ_HANDLED;
1030 }
1031 
1032 static void handle_error(struct mesh_state *ms)
1033 {
1034 	int err, exc, count;
1035 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1036 
1037 	err = in_8(&mr->error);
1038 	exc = in_8(&mr->exception);
1039 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1040 	dlog(ms, "error err/exc/fc/cl=%.8x",
1041 	     MKWORD(err, exc, mr->fifo_count, mr->count_lo));
1042 	if (err & ERR_SCSIRESET) {
1043 		/* SCSI bus was reset */
1044 		printk(KERN_INFO "mesh: SCSI bus reset detected: "
1045 		       "waiting for end...");
1046 		while ((in_8(&mr->bus_status1) & BS1_RST) != 0)
1047 			udelay(1);
1048 		printk("done\n");
1049 		if (ms->dma_started)
1050 			halt_dma(ms);
1051 		handle_reset(ms);
1052 		/* request_q is empty, no point in mesh_start() */
1053 		return;
1054 	}
1055 	if (err & ERR_UNEXPDISC) {
1056 		/* Unexpected disconnect */
1057 		if (exc & EXC_RESELECTED) {
1058 			reselected(ms);
1059 			return;
1060 		}
1061 		if (!ms->aborting) {
1062 			printk(KERN_WARNING "mesh: target %d aborted\n",
1063 			       ms->conn_tgt);
1064 			dumplog(ms, ms->conn_tgt);
1065 			dumpslog(ms);
1066 		}
1067 		out_8(&mr->interrupt, INT_CMDDONE);
1068 		ms->stat = DID_ABORT;
1069 		mesh_done(ms, 1);
1070 		return;
1071 	}
1072 	if (err & ERR_PARITY) {
1073 		if (ms->msgphase == msg_in) {
1074 			printk(KERN_ERR "mesh: msg parity error, target %d\n",
1075 			       ms->conn_tgt);
1076 			ms->msgout[0] = MSG_PARITY_ERROR;
1077 			ms->n_msgout = 1;
1078 			ms->msgphase = msg_in_bad;
1079 			cmd_complete(ms);
1080 			return;
1081 		}
1082 		if (ms->stat == DID_OK) {
1083 			printk(KERN_ERR "mesh: parity error, target %d\n",
1084 			       ms->conn_tgt);
1085 			ms->stat = DID_PARITY;
1086 		}
1087 		count = (mr->count_hi << 8) + mr->count_lo;
1088 		if (count == 0) {
1089 			cmd_complete(ms);
1090 		} else {
1091 			/* reissue the data transfer command */
1092 			out_8(&mr->sequence, mr->sequence);
1093 		}
1094 		return;
1095 	}
1096 	if (err & ERR_SEQERR) {
1097 		if (exc & EXC_RESELECTED) {
1098 			/* This can happen if we issue a command to
1099 			   get the bus just after the target reselects us. */
1100 			static int mesh_resel_seqerr;
1101 			mesh_resel_seqerr++;
1102 			reselected(ms);
1103 			return;
1104 		}
1105 		if (exc == EXC_PHASEMM) {
1106 			static int mesh_phasemm_seqerr;
1107 			mesh_phasemm_seqerr++;
1108 			phase_mismatch(ms);
1109 			return;
1110 		}
1111 		printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
1112 		       err, exc);
1113 	} else {
1114 		printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
1115 	}
1116 	mesh_dump_regs(ms);
1117 	dumplog(ms, ms->conn_tgt);
1118 	if (ms->phase > selecting && (in_8(&mr->bus_status1) & BS1_BSY)) {
1119 		/* try to do what the target wants */
1120 		do_abort(ms);
1121 		phase_mismatch(ms);
1122 		return;
1123 	}
1124 	ms->stat = DID_ERROR;
1125 	mesh_done(ms, 1);
1126 }
1127 
1128 static void handle_exception(struct mesh_state *ms)
1129 {
1130 	int exc;
1131 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1132 
1133 	exc = in_8(&mr->exception);
1134 	out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
1135 	if (exc & EXC_RESELECTED) {
1136 		static int mesh_resel_exc;
1137 		mesh_resel_exc++;
1138 		reselected(ms);
1139 	} else if (exc == EXC_ARBLOST) {
1140 		printk(KERN_DEBUG "mesh: lost arbitration\n");
1141 		ms->stat = DID_BUS_BUSY;
1142 		mesh_done(ms, 1);
1143 	} else if (exc == EXC_SELTO) {
1144 		/* selection timed out */
1145 		ms->stat = DID_BAD_TARGET;
1146 		mesh_done(ms, 1);
1147 	} else if (exc == EXC_PHASEMM) {
1148 		/* target wants to do something different:
1149 		   find out what it wants and do it. */
1150 		phase_mismatch(ms);
1151 	} else {
1152 		printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
1153 		mesh_dump_regs(ms);
1154 		dumplog(ms, ms->conn_tgt);
1155 		do_abort(ms);
1156 		phase_mismatch(ms);
1157 	}
1158 }
1159 
1160 static void handle_msgin(struct mesh_state *ms)
1161 {
1162 	int i, code;
1163 	struct scsi_cmnd *cmd = ms->current_req;
1164 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1165 
1166 	if (ms->n_msgin == 0)
1167 		return;
1168 	code = ms->msgin[0];
1169 	if (ALLOW_DEBUG(ms->conn_tgt)) {
1170 		printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
1171 		for (i = 0; i < ms->n_msgin; ++i)
1172 			printk(" %x", ms->msgin[i]);
1173 		printk("\n");
1174 	}
1175 	dlog(ms, "msgin msg=%.8x",
1176 	     MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
1177 
1178 	ms->expect_reply = 0;
1179 	ms->n_msgout = 0;
1180 	if (ms->n_msgin < msgin_length(ms))
1181 		goto reject;
1182 	if (cmd)
1183 		cmd->SCp.Message = code;
1184 	switch (code) {
1185 	case COMMAND_COMPLETE:
1186 		break;
1187 	case EXTENDED_MESSAGE:
1188 		switch (ms->msgin[2]) {
1189 		case EXTENDED_MODIFY_DATA_POINTER:
1190 			ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
1191 				+ (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
1192 			break;
1193 		case EXTENDED_SDTR:
1194 			if (tp->sdtr_state != sdtr_sent) {
1195 				/* reply with an SDTR */
1196 				add_sdtr_msg(ms);
1197 				/* limit period to at least his value,
1198 				   offset to no more than his */
1199 				if (ms->msgout[3] < ms->msgin[3])
1200 					ms->msgout[3] = ms->msgin[3];
1201 				if (ms->msgout[4] > ms->msgin[4])
1202 					ms->msgout[4] = ms->msgin[4];
1203 				set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
1204 				ms->msgphase = msg_out;
1205 			} else {
1206 				set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
1207 			}
1208 			break;
1209 		default:
1210 			goto reject;
1211 		}
1212 		break;
1213 	case SAVE_POINTERS:
1214 		tp->saved_ptr = ms->data_ptr;
1215 		break;
1216 	case RESTORE_POINTERS:
1217 		ms->data_ptr = tp->saved_ptr;
1218 		break;
1219 	case DISCONNECT:
1220 		ms->phase = disconnecting;
1221 		break;
1222 	case ABORT:
1223 		break;
1224 	case MESSAGE_REJECT:
1225 		if (tp->sdtr_state == sdtr_sent)
1226 			set_sdtr(ms, 0, 0);
1227 		break;
1228 	case NOP:
1229 		break;
1230 	default:
1231 		if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
1232 			if (cmd == NULL) {
1233 				do_abort(ms);
1234 				ms->msgphase = msg_out;
1235 			} else if (code != cmd->device->lun + IDENTIFY_BASE) {
1236 				printk(KERN_WARNING "mesh: lun mismatch "
1237 				       "(%d != %llu) on reselection from "
1238 				       "target %d\n", code - IDENTIFY_BASE,
1239 				       cmd->device->lun, ms->conn_tgt);
1240 			}
1241 			break;
1242 		}
1243 		goto reject;
1244 	}
1245 	return;
1246 
1247  reject:
1248 	printk(KERN_WARNING "mesh: rejecting message from target %d:",
1249 	       ms->conn_tgt);
1250 	for (i = 0; i < ms->n_msgin; ++i)
1251 		printk(" %x", ms->msgin[i]);
1252 	printk("\n");
1253 	ms->msgout[0] = MESSAGE_REJECT;
1254 	ms->n_msgout = 1;
1255 	ms->msgphase = msg_out;
1256 }
1257 
1258 /*
1259  * Set up DMA commands for transferring data.
1260  */
1261 static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
1262 {
1263 	int i, dma_cmd, total, off, dtot;
1264 	struct scatterlist *scl;
1265 	struct dbdma_cmd *dcmds;
1266 
1267 	dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
1268 		OUTPUT_MORE: INPUT_MORE;
1269 	dcmds = ms->dma_cmds;
1270 	dtot = 0;
1271 	if (cmd) {
1272 		int nseg;
1273 
1274 		cmd->SCp.this_residual = scsi_bufflen(cmd);
1275 
1276 		nseg = scsi_dma_map(cmd);
1277 		BUG_ON(nseg < 0);
1278 
1279 		if (nseg) {
1280 			total = 0;
1281 			off = ms->data_ptr;
1282 
1283 			scsi_for_each_sg(cmd, scl, nseg, i) {
1284 				u32 dma_addr = sg_dma_address(scl);
1285 				u32 dma_len = sg_dma_len(scl);
1286 
1287 				total += scl->length;
1288 				if (off >= dma_len) {
1289 					off -= dma_len;
1290 					continue;
1291 				}
1292 				if (dma_len > 0xffff)
1293 					panic("mesh: scatterlist element >= 64k");
1294 				dcmds->req_count = cpu_to_le16(dma_len - off);
1295 				dcmds->command = cpu_to_le16(dma_cmd);
1296 				dcmds->phy_addr = cpu_to_le32(dma_addr + off);
1297 				dcmds->xfer_status = 0;
1298 				++dcmds;
1299 				dtot += dma_len - off;
1300 				off = 0;
1301 			}
1302 		}
1303 	}
1304 	if (dtot == 0) {
1305 		/* Either the target has overrun our buffer,
1306 		   or the caller didn't provide a buffer. */
1307 		static char mesh_extra_buf[64];
1308 
1309 		dtot = sizeof(mesh_extra_buf);
1310 		dcmds->req_count = cpu_to_le16(dtot);
1311 		dcmds->phy_addr = cpu_to_le32(virt_to_phys(mesh_extra_buf));
1312 		dcmds->xfer_status = 0;
1313 		++dcmds;
1314 	}
1315 	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
1316 	dcmds[-1].command = cpu_to_le16(dma_cmd);
1317 	memset(dcmds, 0, sizeof(*dcmds));
1318 	dcmds->command = cpu_to_le16(DBDMA_STOP);
1319 	ms->dma_count = dtot;
1320 }
1321 
1322 static void halt_dma(struct mesh_state *ms)
1323 {
1324 	volatile struct dbdma_regs __iomem *md = ms->dma;
1325 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1326 	struct scsi_cmnd *cmd = ms->current_req;
1327 	int t, nb;
1328 
1329 	if (!ms->tgts[ms->conn_tgt].data_goes_out) {
1330 		/* wait a little while until the fifo drains */
1331 		t = 50;
1332 		while (t > 0 && in_8(&mr->fifo_count) != 0
1333 		       && (in_le32(&md->status) & ACTIVE) != 0) {
1334 			--t;
1335 			udelay(1);
1336 		}
1337 	}
1338 	out_le32(&md->control, RUN << 16);	/* turn off RUN bit */
1339 	nb = (mr->count_hi << 8) + mr->count_lo;
1340 	dlog(ms, "halt_dma fc/count=%.6x",
1341 	     MKWORD(0, mr->fifo_count, 0, nb));
1342 	if (ms->tgts[ms->conn_tgt].data_goes_out)
1343 		nb += mr->fifo_count;
1344 	/* nb is the number of bytes not yet transferred
1345 	   to/from the target. */
1346 	ms->data_ptr -= nb;
1347 	dlog(ms, "data_ptr %x", ms->data_ptr);
1348 	if (ms->data_ptr < 0) {
1349 		printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
1350 		       ms->data_ptr, nb, ms);
1351 		ms->data_ptr = 0;
1352 #ifdef MESH_DBG
1353 		dumplog(ms, ms->conn_tgt);
1354 		dumpslog(ms);
1355 #endif /* MESH_DBG */
1356 	} else if (cmd && scsi_bufflen(cmd) &&
1357 		   ms->data_ptr > scsi_bufflen(cmd)) {
1358 		printk(KERN_DEBUG "mesh: target %d overrun, "
1359 		       "data_ptr=%x total=%x goes_out=%d\n",
1360 		       ms->conn_tgt, ms->data_ptr, scsi_bufflen(cmd),
1361 		       ms->tgts[ms->conn_tgt].data_goes_out);
1362 	}
1363 	if (cmd)
1364 		scsi_dma_unmap(cmd);
1365 	ms->dma_started = 0;
1366 }
1367 
1368 static void phase_mismatch(struct mesh_state *ms)
1369 {
1370 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1371 	int phase;
1372 
1373 	dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
1374 	     MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
1375 	phase = in_8(&mr->bus_status0) & BS0_PHASE;
1376 	if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
1377 		/* output the last byte of the message, without ATN */
1378 		out_8(&mr->count_lo, 1);
1379 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1380 		mesh_flush_io(mr);
1381 		udelay(1);
1382 		out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1383 		ms->msgphase = msg_out_last;
1384 		return;
1385 	}
1386 
1387 	if (ms->msgphase == msg_in) {
1388 		get_msgin(ms);
1389 		if (ms->n_msgin)
1390 			handle_msgin(ms);
1391 	}
1392 
1393 	if (ms->dma_started)
1394 		halt_dma(ms);
1395 	if (mr->fifo_count) {
1396 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1397 		mesh_flush_io(mr);
1398 		udelay(1);
1399 	}
1400 
1401 	ms->msgphase = msg_none;
1402 	switch (phase) {
1403 	case BP_DATAIN:
1404 		ms->tgts[ms->conn_tgt].data_goes_out = 0;
1405 		ms->phase = dataing;
1406 		break;
1407 	case BP_DATAOUT:
1408 		ms->tgts[ms->conn_tgt].data_goes_out = 1;
1409 		ms->phase = dataing;
1410 		break;
1411 	case BP_COMMAND:
1412 		ms->phase = commanding;
1413 		break;
1414 	case BP_STATUS:
1415 		ms->phase = statusing;
1416 		break;
1417 	case BP_MSGIN:
1418 		ms->msgphase = msg_in;
1419 		ms->n_msgin = 0;
1420 		break;
1421 	case BP_MSGOUT:
1422 		ms->msgphase = msg_out;
1423 		if (ms->n_msgout == 0) {
1424 			if (ms->aborting) {
1425 				do_abort(ms);
1426 			} else {
1427 				if (ms->last_n_msgout == 0) {
1428 					printk(KERN_DEBUG
1429 					       "mesh: no msg to repeat\n");
1430 					ms->msgout[0] = NOP;
1431 					ms->last_n_msgout = 1;
1432 				}
1433 				ms->n_msgout = ms->last_n_msgout;
1434 			}
1435 		}
1436 		break;
1437 	default:
1438 		printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
1439 		ms->stat = DID_ERROR;
1440 		mesh_done(ms, 1);
1441 		return;
1442 	}
1443 
1444 	start_phase(ms);
1445 }
1446 
1447 static void cmd_complete(struct mesh_state *ms)
1448 {
1449 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1450 	struct scsi_cmnd *cmd = ms->current_req;
1451 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1452 	int seq, n, t;
1453 
1454 	dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
1455 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
1456 	switch (ms->msgphase) {
1457 	case msg_out_xxx:
1458 		/* huh?  we expected a phase mismatch */
1459 		ms->n_msgin = 0;
1460 		ms->msgphase = msg_in;
1461 		fallthrough;
1462 
1463 	case msg_in:
1464 		/* should have some message bytes in fifo */
1465 		get_msgin(ms);
1466 		n = msgin_length(ms);
1467 		if (ms->n_msgin < n) {
1468 			out_8(&mr->count_lo, n - ms->n_msgin);
1469 			out_8(&mr->sequence, SEQ_MSGIN + seq);
1470 		} else {
1471 			ms->msgphase = msg_none;
1472 			handle_msgin(ms);
1473 			start_phase(ms);
1474 		}
1475 		break;
1476 
1477 	case msg_in_bad:
1478 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1479 		mesh_flush_io(mr);
1480 		udelay(1);
1481 		out_8(&mr->count_lo, 1);
1482 		out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
1483 		break;
1484 
1485 	case msg_out:
1486 		/*
1487 		 * To get the right timing on ATN wrt ACK, we have
1488 		 * to get the MESH to drop ACK, wait until REQ gets
1489 		 * asserted, then drop ATN.  To do this we first
1490 		 * issue a SEQ_MSGOUT with ATN and wait for REQ,
1491 		 * then change the command to a SEQ_MSGOUT w/o ATN.
1492 		 * If we don't see REQ in a reasonable time, we
1493 		 * change the command to SEQ_MSGIN with ATN,
1494 		 * wait for the phase mismatch interrupt, then
1495 		 * issue the SEQ_MSGOUT without ATN.
1496 		 */
1497 		out_8(&mr->count_lo, 1);
1498 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
1499 		t = 30;		/* wait up to 30us */
1500 		while ((in_8(&mr->bus_status0) & BS0_REQ) == 0 && --t >= 0)
1501 			udelay(1);
1502 		dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
1503 		     MKWORD(mr->error, mr->exception,
1504 			    mr->fifo_count, mr->count_lo));
1505 		if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
1506 			/* whoops, target didn't do what we expected */
1507 			ms->last_n_msgout = ms->n_msgout;
1508 			ms->n_msgout = 0;
1509 			if (in_8(&mr->interrupt) & INT_ERROR) {
1510 				printk(KERN_ERR "mesh: error %x in msg_out\n",
1511 				       in_8(&mr->error));
1512 				handle_error(ms);
1513 				return;
1514 			}
1515 			if (in_8(&mr->exception) != EXC_PHASEMM)
1516 				printk(KERN_ERR "mesh: exc %x in msg_out\n",
1517 				       in_8(&mr->exception));
1518 			else
1519 				printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
1520 				       in_8(&mr->bus_status0));
1521 			handle_exception(ms);
1522 			return;
1523 		}
1524 		if (in_8(&mr->bus_status0) & BS0_REQ) {
1525 			out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1526 			mesh_flush_io(mr);
1527 			udelay(1);
1528 			out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1529 			ms->msgphase = msg_out_last;
1530 		} else {
1531 			out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
1532 			ms->msgphase = msg_out_xxx;
1533 		}
1534 		break;
1535 
1536 	case msg_out_last:
1537 		ms->last_n_msgout = ms->n_msgout;
1538 		ms->n_msgout = 0;
1539 		ms->msgphase = ms->expect_reply? msg_in: msg_none;
1540 		start_phase(ms);
1541 		break;
1542 
1543 	case msg_none:
1544 		switch (ms->phase) {
1545 		case idle:
1546 			printk(KERN_ERR "mesh: interrupt in idle phase?\n");
1547 			dumpslog(ms);
1548 			return;
1549 		case selecting:
1550 			dlog(ms, "Selecting phase at command completion",0);
1551 			ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
1552 						 (cmd? cmd->device->lun: 0));
1553 			ms->n_msgout = 1;
1554 			ms->expect_reply = 0;
1555 			if (ms->aborting) {
1556 				ms->msgout[0] = ABORT;
1557 				ms->n_msgout++;
1558 			} else if (tp->sdtr_state == do_sdtr) {
1559 				/* add SDTR message */
1560 				add_sdtr_msg(ms);
1561 				ms->expect_reply = 1;
1562 				tp->sdtr_state = sdtr_sent;
1563 			}
1564 			ms->msgphase = msg_out;
1565 			/*
1566 			 * We need to wait for REQ before dropping ATN.
1567 			 * We wait for at most 30us, then fall back to
1568 			 * a scheme where we issue a SEQ_COMMAND with ATN,
1569 			 * which will give us a phase mismatch interrupt
1570 			 * when REQ does come, and then we send the message.
1571 			 */
1572 			t = 230;		/* wait up to 230us */
1573 			while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
1574 				if (--t < 0) {
1575 					dlog(ms, "impatient for req", ms->n_msgout);
1576 					ms->msgphase = msg_none;
1577 					break;
1578 				}
1579 				udelay(1);
1580 			}
1581 			break;
1582 		case dataing:
1583 			if (ms->dma_count != 0) {
1584 				start_phase(ms);
1585 				return;
1586 			}
1587 			/*
1588 			 * We can get a phase mismatch here if the target
1589 			 * changes to the status phase, even though we have
1590 			 * had a command complete interrupt.  Then, if we
1591 			 * issue the SEQ_STATUS command, we'll get a sequence
1592 			 * error interrupt.  Which isn't so bad except that
1593 			 * occasionally the mesh actually executes the
1594 			 * SEQ_STATUS *as well as* giving us the sequence
1595 			 * error and phase mismatch exception.
1596 			 */
1597 			out_8(&mr->sequence, 0);
1598 			out_8(&mr->interrupt,
1599 			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1600 			halt_dma(ms);
1601 			break;
1602 		case statusing:
1603 			if (cmd) {
1604 				cmd->SCp.Status = mr->fifo;
1605 				if (DEBUG_TARGET(cmd))
1606 					printk(KERN_DEBUG "mesh: status is %x\n",
1607 					       cmd->SCp.Status);
1608 			}
1609 			ms->msgphase = msg_in;
1610 			break;
1611 		case busfreeing:
1612 			mesh_done(ms, 1);
1613 			return;
1614 		case disconnecting:
1615 			ms->current_req = NULL;
1616 			ms->phase = idle;
1617 			mesh_start(ms);
1618 			return;
1619 		default:
1620 			break;
1621 		}
1622 		++ms->phase;
1623 		start_phase(ms);
1624 		break;
1625 	}
1626 }
1627 
1628 
1629 /*
1630  * Called by midlayer with host locked to queue a new
1631  * request
1632  */
1633 static int mesh_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
1634 {
1635 	struct mesh_state *ms;
1636 
1637 	cmd->scsi_done = done;
1638 	cmd->host_scribble = NULL;
1639 
1640 	ms = (struct mesh_state *) cmd->device->host->hostdata;
1641 
1642 	if (ms->request_q == NULL)
1643 		ms->request_q = cmd;
1644 	else
1645 		ms->request_qtail->host_scribble = (void *) cmd;
1646 	ms->request_qtail = cmd;
1647 
1648 	if (ms->phase == idle)
1649 		mesh_start(ms);
1650 
1651 	return 0;
1652 }
1653 
1654 static DEF_SCSI_QCMD(mesh_queue)
1655 
1656 /*
1657  * Called to handle interrupts, either call by the interrupt
1658  * handler (do_mesh_interrupt) or by other functions in
1659  * exceptional circumstances
1660  */
1661 static void mesh_interrupt(struct mesh_state *ms)
1662 {
1663 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1664 	int intr;
1665 
1666 #if 0
1667 	if (ALLOW_DEBUG(ms->conn_tgt))
1668 		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
1669 		       "phase=%d msgphase=%d\n", mr->bus_status0,
1670 		       mr->interrupt, mr->exception, mr->error,
1671 		       ms->phase, ms->msgphase);
1672 #endif
1673 	while ((intr = in_8(&mr->interrupt)) != 0) {
1674 		dlog(ms, "interrupt intr/err/exc/seq=%.8x",
1675 		     MKWORD(intr, mr->error, mr->exception, mr->sequence));
1676 		if (intr & INT_ERROR) {
1677 			handle_error(ms);
1678 		} else if (intr & INT_EXCEPTION) {
1679 			handle_exception(ms);
1680 		} else if (intr & INT_CMDDONE) {
1681 			out_8(&mr->interrupt, INT_CMDDONE);
1682 			cmd_complete(ms);
1683 		}
1684 	}
1685 }
1686 
1687 /* Todo: here we can at least try to remove the command from the
1688  * queue if it isn't connected yet, and for pending command, assert
1689  * ATN until the bus gets freed.
1690  */
1691 static int mesh_abort(struct scsi_cmnd *cmd)
1692 {
1693 	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1694 
1695 	printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
1696 	mesh_dump_regs(ms);
1697 	dumplog(ms, cmd->device->id);
1698 	dumpslog(ms);
1699 	return FAILED;
1700 }
1701 
1702 /*
1703  * Called by the midlayer with the lock held to reset the
1704  * SCSI host and bus.
1705  * The midlayer will wait for devices to come back, we don't need
1706  * to do that ourselves
1707  */
1708 static int mesh_host_reset(struct scsi_cmnd *cmd)
1709 {
1710 	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1711 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1712 	volatile struct dbdma_regs __iomem *md = ms->dma;
1713 	unsigned long flags;
1714 
1715 	printk(KERN_DEBUG "mesh_host_reset\n");
1716 
1717 	spin_lock_irqsave(ms->host->host_lock, flags);
1718 
1719 	if (ms->dma_started)
1720 		halt_dma(ms);
1721 
1722 	/* Reset the controller & dbdma channel */
1723 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
1724 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
1725 	out_8(&mr->error, 0xff);	/* clear all error bits */
1726 	out_8(&mr->sequence, SEQ_RESETMESH);
1727        	mesh_flush_io(mr);
1728 	udelay(1);
1729 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1730 	out_8(&mr->source_id, ms->host->this_id);
1731 	out_8(&mr->sel_timeout, 25);	/* 250ms */
1732 	out_8(&mr->sync_params, ASYNC_PARAMS);
1733 
1734 	/* Reset the bus */
1735 	out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
1736        	mesh_flush_io(mr);
1737 	udelay(30);			/* leave it on for >= 25us */
1738 	out_8(&mr->bus_status1, 0);	/* negate RST */
1739 
1740 	/* Complete pending commands */
1741 	handle_reset(ms);
1742 
1743 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1744 	return SUCCESS;
1745 }
1746 
1747 static void set_mesh_power(struct mesh_state *ms, int state)
1748 {
1749 	if (!machine_is(powermac))
1750 		return;
1751 	if (state) {
1752 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
1753 		msleep(200);
1754 	} else {
1755 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
1756 		msleep(10);
1757 	}
1758 }
1759 
1760 
1761 #ifdef CONFIG_PM
1762 static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
1763 {
1764 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1765 	unsigned long flags;
1766 
1767 	switch (mesg.event) {
1768 	case PM_EVENT_SUSPEND:
1769 	case PM_EVENT_HIBERNATE:
1770 	case PM_EVENT_FREEZE:
1771 		break;
1772 	default:
1773 		return 0;
1774 	}
1775 	if (ms->phase == sleeping)
1776 		return 0;
1777 
1778 	scsi_block_requests(ms->host);
1779 	spin_lock_irqsave(ms->host->host_lock, flags);
1780 	while(ms->phase != idle) {
1781 		spin_unlock_irqrestore(ms->host->host_lock, flags);
1782 		msleep(10);
1783 		spin_lock_irqsave(ms->host->host_lock, flags);
1784 	}
1785 	ms->phase = sleeping;
1786 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1787 	disable_irq(ms->meshintr);
1788 	set_mesh_power(ms, 0);
1789 
1790 	return 0;
1791 }
1792 
1793 static int mesh_resume(struct macio_dev *mdev)
1794 {
1795 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1796 	unsigned long flags;
1797 
1798 	if (ms->phase != sleeping)
1799 		return 0;
1800 
1801 	set_mesh_power(ms, 1);
1802 	mesh_init(ms);
1803 	spin_lock_irqsave(ms->host->host_lock, flags);
1804 	mesh_start(ms);
1805 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1806 	enable_irq(ms->meshintr);
1807 	scsi_unblock_requests(ms->host);
1808 
1809 	return 0;
1810 }
1811 
1812 #endif /* CONFIG_PM */
1813 
1814 /*
1815  * If we leave drives set for synchronous transfers (especially
1816  * CDROMs), and reboot to MacOS, it gets confused, poor thing.
1817  * So, on reboot we reset the SCSI bus.
1818  */
1819 static int mesh_shutdown(struct macio_dev *mdev)
1820 {
1821 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1822 	volatile struct mesh_regs __iomem *mr;
1823 	unsigned long flags;
1824 
1825        	printk(KERN_INFO "resetting MESH scsi bus(es)\n");
1826 	spin_lock_irqsave(ms->host->host_lock, flags);
1827        	mr = ms->mesh;
1828 	out_8(&mr->intr_mask, 0);
1829 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1830 	out_8(&mr->bus_status1, BS1_RST);
1831 	mesh_flush_io(mr);
1832 	udelay(30);
1833 	out_8(&mr->bus_status1, 0);
1834 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1835 
1836 	return 0;
1837 }
1838 
1839 static struct scsi_host_template mesh_template = {
1840 	.proc_name			= "mesh",
1841 	.name				= "MESH",
1842 	.queuecommand			= mesh_queue,
1843 	.eh_abort_handler		= mesh_abort,
1844 	.eh_host_reset_handler		= mesh_host_reset,
1845 	.can_queue			= 20,
1846 	.this_id			= 7,
1847 	.sg_tablesize			= SG_ALL,
1848 	.cmd_per_lun			= 2,
1849 	.max_segment_size		= 65535,
1850 };
1851 
1852 static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
1853 {
1854 	struct device_node *mesh = macio_get_of_node(mdev);
1855 	struct pci_dev* pdev = macio_get_pci_dev(mdev);
1856 	int tgt, minper;
1857 	const int *cfp;
1858 	struct mesh_state *ms;
1859 	struct Scsi_Host *mesh_host;
1860 	void *dma_cmd_space;
1861 	dma_addr_t dma_cmd_bus;
1862 
1863 	switch (mdev->bus->chip->type) {
1864 	case macio_heathrow:
1865 	case macio_gatwick:
1866 	case macio_paddington:
1867 		use_active_neg = 0;
1868 		break;
1869 	default:
1870 		use_active_neg = SEQ_ACTIVE_NEG;
1871 	}
1872 
1873 	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
1874        		printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
1875 	       	       " (got %d,%d)\n", macio_resource_count(mdev),
1876 		       macio_irq_count(mdev));
1877 		return -ENODEV;
1878 	}
1879 
1880 	if (macio_request_resources(mdev, "mesh") != 0) {
1881        		printk(KERN_ERR "mesh: unable to request memory resources");
1882 		return -EBUSY;
1883 	}
1884        	mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
1885 	if (mesh_host == NULL) {
1886 		printk(KERN_ERR "mesh: couldn't register host");
1887 		goto out_release;
1888 	}
1889 
1890 	/* Old junk for root discovery, that will die ultimately */
1891 #if !defined(MODULE)
1892        	note_scsi_host(mesh, mesh_host);
1893 #endif
1894 
1895 	mesh_host->base = macio_resource_start(mdev, 0);
1896 	mesh_host->irq = macio_irq(mdev, 0);
1897        	ms = (struct mesh_state *) mesh_host->hostdata;
1898 	macio_set_drvdata(mdev, ms);
1899 	ms->host = mesh_host;
1900 	ms->mdev = mdev;
1901 	ms->pdev = pdev;
1902 
1903 	ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
1904 	if (ms->mesh == NULL) {
1905 		printk(KERN_ERR "mesh: can't map registers\n");
1906 		goto out_free;
1907 	}
1908 	ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
1909 	if (ms->dma == NULL) {
1910 		printk(KERN_ERR "mesh: can't map registers\n");
1911 		iounmap(ms->mesh);
1912 		goto out_free;
1913 	}
1914 
1915        	ms->meshintr = macio_irq(mdev, 0);
1916        	ms->dmaintr = macio_irq(mdev, 1);
1917 
1918        	/* Space for dma command list: +1 for stop command,
1919        	 * +1 to allow for aligning.
1920 	 */
1921 	ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);
1922 
1923 	/* We use the PCI APIs for now until the generic one gets fixed
1924 	 * enough or until we get some macio-specific versions
1925 	 */
1926 	dma_cmd_space = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev,
1927 					   ms->dma_cmd_size, &dma_cmd_bus,
1928 					   GFP_KERNEL);
1929 	if (dma_cmd_space == NULL) {
1930 		printk(KERN_ERR "mesh: can't allocate DMA table\n");
1931 		goto out_unmap;
1932 	}
1933 
1934 	ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
1935        	ms->dma_cmd_space = dma_cmd_space;
1936 	ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
1937 		- (unsigned long)dma_cmd_space;
1938 	ms->current_req = NULL;
1939        	for (tgt = 0; tgt < 8; ++tgt) {
1940 	       	ms->tgts[tgt].sdtr_state = do_sdtr;
1941 	       	ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1942 	       	ms->tgts[tgt].current_req = NULL;
1943        	}
1944 
1945 	if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
1946        		ms->clk_freq = *cfp;
1947 	else {
1948        		printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
1949 	       	ms->clk_freq = 50000000;
1950        	}
1951 
1952        	/* The maximum sync rate is clock / 5; increase
1953        	 * mesh_sync_period if necessary.
1954 	 */
1955 	minper = 1000000000 / (ms->clk_freq / 5); /* ns */
1956 	if (mesh_sync_period < minper)
1957 		mesh_sync_period = minper;
1958 
1959 	/* Power up the chip */
1960 	set_mesh_power(ms, 1);
1961 
1962 	/* Set it up */
1963        	mesh_init(ms);
1964 
1965 	/* Request interrupt */
1966        	if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
1967 	       	printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
1968 		goto out_shutdown;
1969 	}
1970 
1971 	/* Add scsi host & scan */
1972 	if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
1973 		goto out_release_irq;
1974 	scsi_scan_host(mesh_host);
1975 
1976 	return 0;
1977 
1978  out_release_irq:
1979 	free_irq(ms->meshintr, ms);
1980  out_shutdown:
1981 	/* shutdown & reset bus in case of error or macos can be confused
1982 	 * at reboot if the bus was set to synchronous mode already
1983 	 */
1984 	mesh_shutdown(mdev);
1985 	set_mesh_power(ms, 0);
1986 	dma_free_coherent(&macio_get_pci_dev(mdev)->dev, ms->dma_cmd_size,
1987 			    ms->dma_cmd_space, ms->dma_cmd_bus);
1988  out_unmap:
1989 	iounmap(ms->dma);
1990 	iounmap(ms->mesh);
1991  out_free:
1992 	scsi_host_put(mesh_host);
1993  out_release:
1994 	macio_release_resources(mdev);
1995 
1996 	return -ENODEV;
1997 }
1998 
1999 static int mesh_remove(struct macio_dev *mdev)
2000 {
2001 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
2002 	struct Scsi_Host *mesh_host = ms->host;
2003 
2004 	scsi_remove_host(mesh_host);
2005 
2006 	free_irq(ms->meshintr, ms);
2007 
2008 	/* Reset scsi bus */
2009 	mesh_shutdown(mdev);
2010 
2011 	/* Shut down chip & termination */
2012 	set_mesh_power(ms, 0);
2013 
2014 	/* Unmap registers & dma controller */
2015 	iounmap(ms->mesh);
2016        	iounmap(ms->dma);
2017 
2018 	/* Free DMA commands memory */
2019 	dma_free_coherent(&macio_get_pci_dev(mdev)->dev, ms->dma_cmd_size,
2020 			    ms->dma_cmd_space, ms->dma_cmd_bus);
2021 
2022 	/* Release memory resources */
2023 	macio_release_resources(mdev);
2024 
2025 	scsi_host_put(mesh_host);
2026 
2027 	return 0;
2028 }
2029 
2030 
2031 static struct of_device_id mesh_match[] =
2032 {
2033 	{
2034 	.name 		= "mesh",
2035 	},
2036 	{
2037 	.type		= "scsi",
2038 	.compatible	= "chrp,mesh0"
2039 	},
2040 	{},
2041 };
2042 MODULE_DEVICE_TABLE (of, mesh_match);
2043 
2044 static struct macio_driver mesh_driver =
2045 {
2046 	.driver = {
2047 		.name 		= "mesh",
2048 		.owner		= THIS_MODULE,
2049 		.of_match_table	= mesh_match,
2050 	},
2051 	.probe		= mesh_probe,
2052 	.remove		= mesh_remove,
2053 	.shutdown	= mesh_shutdown,
2054 #ifdef CONFIG_PM
2055 	.suspend	= mesh_suspend,
2056 	.resume		= mesh_resume,
2057 #endif
2058 };
2059 
2060 
2061 static int __init init_mesh(void)
2062 {
2063 
2064 	/* Calculate sync rate from module parameters */
2065 	if (sync_rate > 10)
2066 		sync_rate = 10;
2067 	if (sync_rate > 0) {
2068 		printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
2069 		mesh_sync_period = 1000 / sync_rate;	/* ns */
2070 		mesh_sync_offset = 15;
2071 	} else
2072 		printk(KERN_INFO "mesh: configured for asynchronous\n");
2073 
2074 	return macio_register_driver(&mesh_driver);
2075 }
2076 
2077 static void __exit exit_mesh(void)
2078 {
2079 	return macio_unregister_driver(&mesh_driver);
2080 }
2081 
2082 module_init(init_mesh);
2083 module_exit(exit_mesh);
2084