xref: /linux/drivers/scsi/mesh.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
1 /*
2  * SCSI low-level driver for the MESH (Macintosh Enhanced SCSI Hardware)
3  * bus adaptor found on Power Macintosh computers.
4  * We assume the MESH is connected to a DBDMA (descriptor-based DMA)
5  * controller.
6  *
7  * Paul Mackerras, August 1996.
8  * Copyright (C) 1996 Paul Mackerras.
9  *
10  * Apr. 21 2002  - BenH		Rework bus reset code for new error handler
11  *                              Add delay after initial bus reset
12  *                              Add module parameters
13  *
14  * Sep. 27 2003  - BenH		Move to new driver model, fix some write posting
15  *				issues
16  * To do:
17  * - handle aborts correctly
18  * - retry arbitration if lost (unless higher levels do this for us)
19  * - power down the chip when no device is detected
20  */
21 #include <linux/module.h>
22 #include <linux/kernel.h>
23 #include <linux/delay.h>
24 #include <linux/types.h>
25 #include <linux/string.h>
26 #include <linux/slab.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 <asm/dbdma.h>
34 #include <asm/io.h>
35 #include <asm/pgtable.h>
36 #include <asm/prom.h>
37 #include <asm/system.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/pci-bridge.h>
44 #include <asm/macio.h>
45 
46 #include <scsi/scsi.h>
47 #include <scsi/scsi_cmnd.h>
48 #include <scsi/scsi_device.h>
49 #include <scsi/scsi_host.h>
50 
51 #include "mesh.h"
52 
53 #if 1
54 #undef KERN_DEBUG
55 #define KERN_DEBUG KERN_WARNING
56 #endif
57 
58 MODULE_AUTHOR("Paul Mackerras (paulus@samba.org)");
59 MODULE_DESCRIPTION("PowerMac MESH SCSI driver");
60 MODULE_LICENSE("GPL");
61 
62 static int sync_rate = CONFIG_SCSI_MESH_SYNC_RATE;
63 static int sync_targets = 0xff;
64 static int resel_targets = 0xff;
65 static int debug_targets = 0;	/* print debug for these targets */
66 static int init_reset_delay = CONFIG_SCSI_MESH_RESET_DELAY_MS;
67 
68 module_param(sync_rate, int, 0);
69 MODULE_PARM_DESC(sync_rate, "Synchronous rate (0..10, 0=async)");
70 module_param(sync_targets, int, 0);
71 MODULE_PARM_DESC(sync_targets, "Bitmask of targets allowed to set synchronous");
72 module_param(resel_targets, int, 0);
73 MODULE_PARM_DESC(resel_targets, "Bitmask of targets allowed to set disconnect");
74 module_param(debug_targets, int, 0644);
75 MODULE_PARM_DESC(debug_targets, "Bitmask of debugged targets");
76 module_param(init_reset_delay, int, 0);
77 MODULE_PARM_DESC(init_reset_delay, "Initial bus reset delay (0=no reset)");
78 
79 static int mesh_sync_period = 100;
80 static int mesh_sync_offset = 0;
81 static unsigned char use_active_neg = 0;  /* bit mask for SEQ_ACTIVE_NEG if used */
82 
83 #define ALLOW_SYNC(tgt)		((sync_targets >> (tgt)) & 1)
84 #define ALLOW_RESEL(tgt)	((resel_targets >> (tgt)) & 1)
85 #define ALLOW_DEBUG(tgt)	((debug_targets >> (tgt)) & 1)
86 #define DEBUG_TARGET(cmd)	((cmd) && ALLOW_DEBUG((cmd)->device->id))
87 
88 #undef MESH_DBG
89 #define N_DBG_LOG	50
90 #define N_DBG_SLOG	20
91 #define NUM_DBG_EVENTS	13
92 #undef	DBG_USE_TB		/* bombs on 601 */
93 
94 struct dbglog {
95 	char	*fmt;
96 	u32	tb;
97 	u8	phase;
98 	u8	bs0;
99 	u8	bs1;
100 	u8	tgt;
101 	int	d;
102 };
103 
104 enum mesh_phase {
105 	idle,
106 	arbitrating,
107 	selecting,
108 	commanding,
109 	dataing,
110 	statusing,
111 	busfreeing,
112 	disconnecting,
113 	reselecting,
114 	sleeping
115 };
116 
117 enum msg_phase {
118 	msg_none,
119 	msg_out,
120 	msg_out_xxx,
121 	msg_out_last,
122 	msg_in,
123 	msg_in_bad,
124 };
125 
126 enum sdtr_phase {
127 	do_sdtr,
128 	sdtr_sent,
129 	sdtr_done
130 };
131 
132 struct mesh_target {
133 	enum sdtr_phase sdtr_state;
134 	int	sync_params;
135 	int	data_goes_out;		/* guess as to data direction */
136 	struct scsi_cmnd *current_req;
137 	u32	saved_ptr;
138 #ifdef MESH_DBG
139 	int	log_ix;
140 	int	n_log;
141 	struct dbglog log[N_DBG_LOG];
142 #endif
143 };
144 
145 struct mesh_state {
146 	volatile struct	mesh_regs __iomem *mesh;
147 	int	meshintr;
148 	volatile struct	dbdma_regs __iomem *dma;
149 	int	dmaintr;
150 	struct	Scsi_Host *host;
151 	struct	mesh_state *next;
152 	struct scsi_cmnd *request_q;
153 	struct scsi_cmnd *request_qtail;
154 	enum mesh_phase phase;		/* what we're currently trying to do */
155 	enum msg_phase msgphase;
156 	int	conn_tgt;		/* target we're connected to */
157 	struct scsi_cmnd *current_req;		/* req we're currently working on */
158 	int	data_ptr;
159 	int	dma_started;
160 	int	dma_count;
161 	int	stat;
162 	int	aborting;
163 	int	expect_reply;
164 	int	n_msgin;
165 	u8	msgin[16];
166 	int	n_msgout;
167 	int	last_n_msgout;
168 	u8	msgout[16];
169 	struct dbdma_cmd *dma_cmds;	/* space for dbdma commands, aligned */
170 	dma_addr_t dma_cmd_bus;
171 	void	*dma_cmd_space;
172 	int	dma_cmd_size;
173 	int	clk_freq;
174 	struct mesh_target tgts[8];
175 	struct macio_dev *mdev;
176 	struct pci_dev* pdev;
177 #ifdef MESH_DBG
178 	int	log_ix;
179 	int	n_log;
180 	struct dbglog log[N_DBG_SLOG];
181 #endif
182 };
183 
184 /*
185  * Driver is too messy, we need a few prototypes...
186  */
187 static void mesh_done(struct mesh_state *ms, int start_next);
188 static void mesh_interrupt(struct mesh_state *ms);
189 static void cmd_complete(struct mesh_state *ms);
190 static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd);
191 static void halt_dma(struct mesh_state *ms);
192 static void phase_mismatch(struct mesh_state *ms);
193 
194 
195 /*
196  * Some debugging & logging routines
197  */
198 
199 #ifdef MESH_DBG
200 
201 static inline u32 readtb(void)
202 {
203 	u32 tb;
204 
205 #ifdef DBG_USE_TB
206 	/* Beware: if you enable this, it will crash on 601s. */
207 	asm ("mftb %0" : "=r" (tb) : );
208 #else
209 	tb = 0;
210 #endif
211 	return tb;
212 }
213 
214 static void dlog(struct mesh_state *ms, char *fmt, int a)
215 {
216 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
217 	struct dbglog *tlp, *slp;
218 
219 	tlp = &tp->log[tp->log_ix];
220 	slp = &ms->log[ms->log_ix];
221 	tlp->fmt = fmt;
222 	tlp->tb = readtb();
223 	tlp->phase = (ms->msgphase << 4) + ms->phase;
224 	tlp->bs0 = ms->mesh->bus_status0;
225 	tlp->bs1 = ms->mesh->bus_status1;
226 	tlp->tgt = ms->conn_tgt;
227 	tlp->d = a;
228 	*slp = *tlp;
229 	if (++tp->log_ix >= N_DBG_LOG)
230 		tp->log_ix = 0;
231 	if (tp->n_log < N_DBG_LOG)
232 		++tp->n_log;
233 	if (++ms->log_ix >= N_DBG_SLOG)
234 		ms->log_ix = 0;
235 	if (ms->n_log < N_DBG_SLOG)
236 		++ms->n_log;
237 }
238 
239 static void dumplog(struct mesh_state *ms, int t)
240 {
241 	struct mesh_target *tp = &ms->tgts[t];
242 	struct dbglog *lp;
243 	int i;
244 
245 	if (tp->n_log == 0)
246 		return;
247 	i = tp->log_ix - tp->n_log;
248 	if (i < 0)
249 		i += N_DBG_LOG;
250 	tp->n_log = 0;
251 	do {
252 		lp = &tp->log[i];
253 		printk(KERN_DEBUG "mesh log %d: bs=%.2x%.2x ph=%.2x ",
254 		       t, lp->bs1, lp->bs0, lp->phase);
255 #ifdef DBG_USE_TB
256 		printk("tb=%10u ", lp->tb);
257 #endif
258 		printk(lp->fmt, lp->d);
259 		printk("\n");
260 		if (++i >= N_DBG_LOG)
261 			i = 0;
262 	} while (i != tp->log_ix);
263 }
264 
265 static void dumpslog(struct mesh_state *ms)
266 {
267 	struct dbglog *lp;
268 	int i;
269 
270 	if (ms->n_log == 0)
271 		return;
272 	i = ms->log_ix - ms->n_log;
273 	if (i < 0)
274 		i += N_DBG_SLOG;
275 	ms->n_log = 0;
276 	do {
277 		lp = &ms->log[i];
278 		printk(KERN_DEBUG "mesh log: bs=%.2x%.2x ph=%.2x t%d ",
279 		       lp->bs1, lp->bs0, lp->phase, lp->tgt);
280 #ifdef DBG_USE_TB
281 		printk("tb=%10u ", lp->tb);
282 #endif
283 		printk(lp->fmt, lp->d);
284 		printk("\n");
285 		if (++i >= N_DBG_SLOG)
286 			i = 0;
287 	} while (i != ms->log_ix);
288 }
289 
290 #else
291 
292 static inline void dlog(struct mesh_state *ms, char *fmt, int a)
293 {}
294 static inline void dumplog(struct mesh_state *ms, int tgt)
295 {}
296 static inline void dumpslog(struct mesh_state *ms)
297 {}
298 
299 #endif /* MESH_DBG */
300 
301 #define MKWORD(a, b, c, d)	(((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
302 
303 static void
304 mesh_dump_regs(struct mesh_state *ms)
305 {
306 	volatile struct mesh_regs __iomem *mr = ms->mesh;
307 	volatile struct dbdma_regs __iomem *md = ms->dma;
308 	int t;
309 	struct mesh_target *tp;
310 
311 	printk(KERN_DEBUG "mesh: state at %p, regs at %p, dma at %p\n",
312 	       ms, mr, md);
313 	printk(KERN_DEBUG "    ct=%4x seq=%2x bs=%4x fc=%2x "
314 	       "exc=%2x err=%2x im=%2x int=%2x sp=%2x\n",
315 	       (mr->count_hi << 8) + mr->count_lo, mr->sequence,
316 	       (mr->bus_status1 << 8) + mr->bus_status0, mr->fifo_count,
317 	       mr->exception, mr->error, mr->intr_mask, mr->interrupt,
318 	       mr->sync_params);
319 	while(in_8(&mr->fifo_count))
320 		printk(KERN_DEBUG " fifo data=%.2x\n",in_8(&mr->fifo));
321 	printk(KERN_DEBUG "    dma stat=%x cmdptr=%x\n",
322 	       in_le32(&md->status), in_le32(&md->cmdptr));
323 	printk(KERN_DEBUG "    phase=%d msgphase=%d conn_tgt=%d data_ptr=%d\n",
324 	       ms->phase, ms->msgphase, ms->conn_tgt, ms->data_ptr);
325 	printk(KERN_DEBUG "    dma_st=%d dma_ct=%d n_msgout=%d\n",
326 	       ms->dma_started, ms->dma_count, ms->n_msgout);
327 	for (t = 0; t < 8; ++t) {
328 		tp = &ms->tgts[t];
329 		if (tp->current_req == NULL)
330 			continue;
331 		printk(KERN_DEBUG "    target %d: req=%p goes_out=%d saved_ptr=%d\n",
332 		       t, tp->current_req, tp->data_goes_out, tp->saved_ptr);
333 	}
334 }
335 
336 
337 /*
338  * Flush write buffers on the bus path to the mesh
339  */
340 static inline void mesh_flush_io(volatile struct mesh_regs __iomem *mr)
341 {
342 	(void)in_8(&mr->mesh_id);
343 }
344 
345 
346 /*
347  * Complete a SCSI command
348  */
349 static void mesh_completed(struct mesh_state *ms, struct scsi_cmnd *cmd)
350 {
351 	(*cmd->scsi_done)(cmd);
352 }
353 
354 
355 /* Called with  meshinterrupt disabled, initialize the chipset
356  * and eventually do the initial bus reset. The lock must not be
357  * held since we can schedule.
358  */
359 static void mesh_init(struct mesh_state *ms)
360 {
361 	volatile struct mesh_regs __iomem *mr = ms->mesh;
362 	volatile struct dbdma_regs __iomem *md = ms->dma;
363 
364 	mesh_flush_io(mr);
365 	udelay(100);
366 
367 	/* Reset controller */
368 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
369 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
370 	out_8(&mr->error, 0xff);	/* clear all error bits */
371 	out_8(&mr->sequence, SEQ_RESETMESH);
372 	mesh_flush_io(mr);
373 	udelay(10);
374 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
375 	out_8(&mr->source_id, ms->host->this_id);
376 	out_8(&mr->sel_timeout, 25);	/* 250ms */
377 	out_8(&mr->sync_params, ASYNC_PARAMS);
378 
379 	if (init_reset_delay) {
380 		printk(KERN_INFO "mesh: performing initial bus reset...\n");
381 
382 		/* Reset bus */
383 		out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
384 		mesh_flush_io(mr);
385 		udelay(30);			/* leave it on for >= 25us */
386 		out_8(&mr->bus_status1, 0);	/* negate RST */
387 		mesh_flush_io(mr);
388 
389 		/* Wait for bus to come back */
390 		msleep(init_reset_delay);
391 	}
392 
393 	/* Reconfigure controller */
394 	out_8(&mr->interrupt, 0xff);	/* clear all interrupt bits */
395 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
396 	mesh_flush_io(mr);
397 	udelay(1);
398 	out_8(&mr->sync_params, ASYNC_PARAMS);
399 	out_8(&mr->sequence, SEQ_ENBRESEL);
400 
401 	ms->phase = idle;
402 	ms->msgphase = msg_none;
403 }
404 
405 
406 static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
407 {
408 	volatile struct mesh_regs __iomem *mr = ms->mesh;
409 	int t, id;
410 
411 	id = cmd->device->id;
412 	ms->current_req = cmd;
413 	ms->tgts[id].data_goes_out = cmd->sc_data_direction == DMA_TO_DEVICE;
414 	ms->tgts[id].current_req = cmd;
415 
416 #if 1
417 	if (DEBUG_TARGET(cmd)) {
418 		int i;
419 		printk(KERN_DEBUG "mesh_start: %p ser=%lu tgt=%d cmd=",
420 		       cmd, cmd->serial_number, id);
421 		for (i = 0; i < cmd->cmd_len; ++i)
422 			printk(" %x", cmd->cmnd[i]);
423 		printk(" use_sg=%d buffer=%p bufflen=%u\n",
424 		       scsi_sg_count(cmd), scsi_sglist(cmd), scsi_bufflen(cmd));
425 	}
426 #endif
427 	if (ms->dma_started)
428 		panic("mesh: double DMA start !\n");
429 
430 	ms->phase = arbitrating;
431 	ms->msgphase = msg_none;
432 	ms->data_ptr = 0;
433 	ms->dma_started = 0;
434 	ms->n_msgout = 0;
435 	ms->last_n_msgout = 0;
436 	ms->expect_reply = 0;
437 	ms->conn_tgt = id;
438 	ms->tgts[id].saved_ptr = 0;
439 	ms->stat = DID_OK;
440 	ms->aborting = 0;
441 #ifdef MESH_DBG
442 	ms->tgts[id].n_log = 0;
443 	dlog(ms, "start cmd=%x", (int) cmd);
444 #endif
445 
446 	/* Off we go */
447 	dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
448 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
449 	out_8(&mr->interrupt, INT_CMDDONE);
450 	out_8(&mr->sequence, SEQ_ENBRESEL);
451 	mesh_flush_io(mr);
452 	udelay(1);
453 
454 	if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
455 		/*
456 		 * Some other device has the bus or is arbitrating for it -
457 		 * probably a target which is about to reselect us.
458 		 */
459 		dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
460 		     MKWORD(mr->interrupt, mr->exception,
461 			    mr->error, mr->fifo_count));
462 		for (t = 100; t > 0; --t) {
463 			if ((in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) == 0)
464 				break;
465 			if (in_8(&mr->interrupt) != 0) {
466 				dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
467 				     MKWORD(mr->interrupt, mr->exception,
468 					    mr->error, mr->fifo_count));
469 				mesh_interrupt(ms);
470 				if (ms->phase != arbitrating)
471 					return;
472 			}
473 			udelay(1);
474 		}
475 		if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
476 			/* XXX should try again in a little while */
477 			ms->stat = DID_BUS_BUSY;
478 			ms->phase = idle;
479 			mesh_done(ms, 0);
480 			return;
481 		}
482 	}
483 
484 	/*
485 	 * Apparently the mesh has a bug where it will assert both its
486 	 * own bit and the target's bit on the bus during arbitration.
487 	 */
488 	out_8(&mr->dest_id, mr->source_id);
489 
490 	/*
491 	 * There appears to be a race with reselection sometimes,
492 	 * where a target reselects us just as we issue the
493 	 * arbitrate command.  It seems that then the arbitrate
494 	 * command just hangs waiting for the bus to be free
495 	 * without giving us a reselection exception.
496 	 * The only way I have found to get it to respond correctly
497 	 * is this: disable reselection before issuing the arbitrate
498 	 * command, then after issuing it, if it looks like a target
499 	 * is trying to reselect us, reset the mesh and then enable
500 	 * reselection.
501 	 */
502 	out_8(&mr->sequence, SEQ_DISRESEL);
503 	if (in_8(&mr->interrupt) != 0) {
504 		dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
505 		     MKWORD(mr->interrupt, mr->exception,
506 			    mr->error, mr->fifo_count));
507 		mesh_interrupt(ms);
508 		if (ms->phase != arbitrating)
509 			return;
510 		dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
511 		     MKWORD(mr->interrupt, mr->exception,
512 			    mr->error, mr->fifo_count));
513 	}
514 
515 	out_8(&mr->sequence, SEQ_ARBITRATE);
516 
517 	for (t = 230; t > 0; --t) {
518 		if (in_8(&mr->interrupt) != 0)
519 			break;
520 		udelay(1);
521 	}
522 	dlog(ms, "after arb, intr/exc/err/fc=%.8x",
523 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
524 	if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
525 	    && (in_8(&mr->bus_status0) & BS0_IO)) {
526 		/* looks like a reselection - try resetting the mesh */
527 		dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
528 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
529 		out_8(&mr->sequence, SEQ_RESETMESH);
530 		mesh_flush_io(mr);
531 		udelay(10);
532 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
533 		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
534 		out_8(&mr->sequence, SEQ_ENBRESEL);
535 		mesh_flush_io(mr);
536 		for (t = 10; t > 0 && in_8(&mr->interrupt) == 0; --t)
537 			udelay(1);
538 		dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
539 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
540 #ifndef MESH_MULTIPLE_HOSTS
541 		if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
542 		    && (in_8(&mr->bus_status0) & BS0_IO)) {
543 			printk(KERN_ERR "mesh: controller not responding"
544 			       " to reselection!\n");
545 			/*
546 			 * If this is a target reselecting us, and the
547 			 * mesh isn't responding, the higher levels of
548 			 * the scsi code will eventually time out and
549 			 * reset the bus.
550 			 */
551 		}
552 #endif
553 	}
554 }
555 
556 /*
557  * Start the next command for a MESH.
558  * Should be called with interrupts disabled.
559  */
560 static void mesh_start(struct mesh_state *ms)
561 {
562 	struct scsi_cmnd *cmd, *prev, *next;
563 
564 	if (ms->phase != idle || ms->current_req != NULL) {
565 		printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
566 		       ms->phase, ms);
567 		return;
568 	}
569 
570 	while (ms->phase == idle) {
571 		prev = NULL;
572 		for (cmd = ms->request_q; ; cmd = (struct scsi_cmnd *) cmd->host_scribble) {
573 			if (cmd == NULL)
574 				return;
575 			if (ms->tgts[cmd->device->id].current_req == NULL)
576 				break;
577 			prev = cmd;
578 		}
579 		next = (struct scsi_cmnd *) cmd->host_scribble;
580 		if (prev == NULL)
581 			ms->request_q = next;
582 		else
583 			prev->host_scribble = (void *) next;
584 		if (next == NULL)
585 			ms->request_qtail = prev;
586 
587 		mesh_start_cmd(ms, cmd);
588 	}
589 }
590 
591 static void mesh_done(struct mesh_state *ms, int start_next)
592 {
593 	struct scsi_cmnd *cmd;
594 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
595 
596 	cmd = ms->current_req;
597 	ms->current_req = NULL;
598 	tp->current_req = NULL;
599 	if (cmd) {
600 		cmd->result = (ms->stat << 16) + cmd->SCp.Status;
601 		if (ms->stat == DID_OK)
602 			cmd->result += (cmd->SCp.Message << 8);
603 		if (DEBUG_TARGET(cmd)) {
604 			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
605 			       cmd->result, ms->data_ptr, scsi_bufflen(cmd));
606 #if 0
607 			/* needs to use sg? */
608 			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
609 			    && cmd->request_buffer != 0) {
610 				unsigned char *b = cmd->request_buffer;
611 				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
612 				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
613 			}
614 #endif
615 		}
616 		cmd->SCp.this_residual -= ms->data_ptr;
617 		mesh_completed(ms, cmd);
618 	}
619 	if (start_next) {
620 		out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
621 		mesh_flush_io(ms->mesh);
622 		udelay(1);
623 		ms->phase = idle;
624 		mesh_start(ms);
625 	}
626 }
627 
628 static inline void add_sdtr_msg(struct mesh_state *ms)
629 {
630 	int i = ms->n_msgout;
631 
632 	ms->msgout[i] = EXTENDED_MESSAGE;
633 	ms->msgout[i+1] = 3;
634 	ms->msgout[i+2] = EXTENDED_SDTR;
635 	ms->msgout[i+3] = mesh_sync_period/4;
636 	ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
637 	ms->n_msgout = i + 5;
638 }
639 
640 static void set_sdtr(struct mesh_state *ms, int period, int offset)
641 {
642 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
643 	volatile struct mesh_regs __iomem *mr = ms->mesh;
644 	int v, tr;
645 
646 	tp->sdtr_state = sdtr_done;
647 	if (offset == 0) {
648 		/* asynchronous */
649 		if (SYNC_OFF(tp->sync_params))
650 			printk(KERN_INFO "mesh: target %d now asynchronous\n",
651 			       ms->conn_tgt);
652 		tp->sync_params = ASYNC_PARAMS;
653 		out_8(&mr->sync_params, ASYNC_PARAMS);
654 		return;
655 	}
656 	/*
657 	 * We need to compute ceil(clk_freq * period / 500e6) - 2
658 	 * without incurring overflow.
659 	 */
660 	v = (ms->clk_freq / 5000) * period;
661 	if (v <= 250000) {
662 		/* special case: sync_period == 5 * clk_period */
663 		v = 0;
664 		/* units of tr are 100kB/s */
665 		tr = (ms->clk_freq + 250000) / 500000;
666 	} else {
667 		/* sync_period == (v + 2) * 2 * clk_period */
668 		v = (v + 99999) / 100000 - 2;
669 		if (v > 15)
670 			v = 15;	/* oops */
671 		tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
672 	}
673 	if (offset > 15)
674 		offset = 15;	/* can't happen */
675 	tp->sync_params = SYNC_PARAMS(offset, v);
676 	out_8(&mr->sync_params, tp->sync_params);
677 	printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
678 	       ms->conn_tgt, tr/10, tr%10);
679 }
680 
681 static void start_phase(struct mesh_state *ms)
682 {
683 	int i, seq, nb;
684 	volatile struct mesh_regs __iomem *mr = ms->mesh;
685 	volatile struct dbdma_regs __iomem *md = ms->dma;
686 	struct scsi_cmnd *cmd = ms->current_req;
687 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
688 
689 	dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
690 	     MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
691 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
692 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
693 	switch (ms->msgphase) {
694 	case msg_none:
695 		break;
696 
697 	case msg_in:
698 		out_8(&mr->count_hi, 0);
699 		out_8(&mr->count_lo, 1);
700 		out_8(&mr->sequence, SEQ_MSGIN + seq);
701 		ms->n_msgin = 0;
702 		return;
703 
704 	case msg_out:
705 		/*
706 		 * To make sure ATN drops before we assert ACK for
707 		 * the last byte of the message, we have to do the
708 		 * last byte specially.
709 		 */
710 		if (ms->n_msgout <= 0) {
711 			printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
712 			       ms->n_msgout);
713 			mesh_dump_regs(ms);
714 			ms->msgphase = msg_none;
715 			break;
716 		}
717 		if (ALLOW_DEBUG(ms->conn_tgt)) {
718 			printk(KERN_DEBUG "mesh: sending %d msg bytes:",
719 			       ms->n_msgout);
720 			for (i = 0; i < ms->n_msgout; ++i)
721 				printk(" %x", ms->msgout[i]);
722 			printk("\n");
723 		}
724 		dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
725 						ms->msgout[1], ms->msgout[2]));
726 		out_8(&mr->count_hi, 0);
727 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
728 		mesh_flush_io(mr);
729 		udelay(1);
730 		/*
731 		 * If ATN is not already asserted, we assert it, then
732 		 * issue a SEQ_MSGOUT to get the mesh to drop ACK.
733 		 */
734 		if ((in_8(&mr->bus_status0) & BS0_ATN) == 0) {
735 			dlog(ms, "bus0 was %.2x explicitly asserting ATN", mr->bus_status0);
736 			out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
737 			mesh_flush_io(mr);
738 			udelay(1);
739 			out_8(&mr->count_lo, 1);
740 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
741 			out_8(&mr->bus_status0, 0); /* release explicit ATN */
742 			dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
743 		}
744 		if (ms->n_msgout == 1) {
745 			/*
746 			 * We can't issue the SEQ_MSGOUT without ATN
747 			 * until the target has asserted REQ.  The logic
748 			 * in cmd_complete handles both situations:
749 			 * REQ already asserted or not.
750 			 */
751 			cmd_complete(ms);
752 		} else {
753 			out_8(&mr->count_lo, ms->n_msgout - 1);
754 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
755 			for (i = 0; i < ms->n_msgout - 1; ++i)
756 				out_8(&mr->fifo, ms->msgout[i]);
757 		}
758 		return;
759 
760 	default:
761 		printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
762 		       ms->msgphase);
763 	}
764 
765 	switch (ms->phase) {
766 	case selecting:
767 		out_8(&mr->dest_id, ms->conn_tgt);
768 		out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
769 		break;
770 	case commanding:
771 		out_8(&mr->sync_params, tp->sync_params);
772 		out_8(&mr->count_hi, 0);
773 		if (cmd) {
774 			out_8(&mr->count_lo, cmd->cmd_len);
775 			out_8(&mr->sequence, SEQ_COMMAND + seq);
776 			for (i = 0; i < cmd->cmd_len; ++i)
777 				out_8(&mr->fifo, cmd->cmnd[i]);
778 		} else {
779 			out_8(&mr->count_lo, 6);
780 			out_8(&mr->sequence, SEQ_COMMAND + seq);
781 			for (i = 0; i < 6; ++i)
782 				out_8(&mr->fifo, 0);
783 		}
784 		break;
785 	case dataing:
786 		/* transfer data, if any */
787 		if (!ms->dma_started) {
788 			set_dma_cmds(ms, cmd);
789 			out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
790 			out_le32(&md->control, (RUN << 16) | RUN);
791 			ms->dma_started = 1;
792 		}
793 		nb = ms->dma_count;
794 		if (nb > 0xfff0)
795 			nb = 0xfff0;
796 		ms->dma_count -= nb;
797 		ms->data_ptr += nb;
798 		out_8(&mr->count_lo, nb);
799 		out_8(&mr->count_hi, nb >> 8);
800 		out_8(&mr->sequence, (tp->data_goes_out?
801 				SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
802 		break;
803 	case statusing:
804 		out_8(&mr->count_hi, 0);
805 		out_8(&mr->count_lo, 1);
806 		out_8(&mr->sequence, SEQ_STATUS + seq);
807 		break;
808 	case busfreeing:
809 	case disconnecting:
810 		out_8(&mr->sequence, SEQ_ENBRESEL);
811 		mesh_flush_io(mr);
812 		udelay(1);
813 		dlog(ms, "enbresel intr/exc/err/fc=%.8x",
814 		     MKWORD(mr->interrupt, mr->exception, mr->error,
815 			    mr->fifo_count));
816 		out_8(&mr->sequence, SEQ_BUSFREE);
817 		break;
818 	default:
819 		printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
820 		       ms->phase);
821 		dumpslog(ms);
822 	}
823 
824 }
825 
826 static inline void get_msgin(struct mesh_state *ms)
827 {
828 	volatile struct mesh_regs __iomem *mr = ms->mesh;
829 	int i, n;
830 
831 	n = mr->fifo_count;
832 	if (n != 0) {
833 		i = ms->n_msgin;
834 		ms->n_msgin = i + n;
835 		for (; n > 0; --n)
836 			ms->msgin[i++] = in_8(&mr->fifo);
837 	}
838 }
839 
840 static inline int msgin_length(struct mesh_state *ms)
841 {
842 	int b, n;
843 
844 	n = 1;
845 	if (ms->n_msgin > 0) {
846 		b = ms->msgin[0];
847 		if (b == 1) {
848 			/* extended message */
849 			n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
850 		} else if (0x20 <= b && b <= 0x2f) {
851 			/* 2-byte message */
852 			n = 2;
853 		}
854 	}
855 	return n;
856 }
857 
858 static void reselected(struct mesh_state *ms)
859 {
860 	volatile struct mesh_regs __iomem *mr = ms->mesh;
861 	struct scsi_cmnd *cmd;
862 	struct mesh_target *tp;
863 	int b, t, prev;
864 
865 	switch (ms->phase) {
866 	case idle:
867 		break;
868 	case arbitrating:
869 		if ((cmd = ms->current_req) != NULL) {
870 			/* put the command back on the queue */
871 			cmd->host_scribble = (void *) ms->request_q;
872 			if (ms->request_q == NULL)
873 				ms->request_qtail = cmd;
874 			ms->request_q = cmd;
875 			tp = &ms->tgts[cmd->device->id];
876 			tp->current_req = NULL;
877 		}
878 		break;
879 	case busfreeing:
880 		ms->phase = reselecting;
881 		mesh_done(ms, 0);
882 		break;
883 	case disconnecting:
884 		break;
885 	default:
886 		printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
887 		       ms->msgphase, ms->phase, ms->conn_tgt);
888 		dumplog(ms, ms->conn_tgt);
889 		dumpslog(ms);
890 	}
891 
892 	if (ms->dma_started) {
893 		printk(KERN_ERR "mesh: reselected with DMA started !\n");
894 		halt_dma(ms);
895 	}
896 	ms->current_req = NULL;
897 	ms->phase = dataing;
898 	ms->msgphase = msg_in;
899 	ms->n_msgout = 0;
900 	ms->last_n_msgout = 0;
901 	prev = ms->conn_tgt;
902 
903 	/*
904 	 * We seem to get abortive reselections sometimes.
905 	 */
906 	while ((in_8(&mr->bus_status1) & BS1_BSY) == 0) {
907 		static int mesh_aborted_resels;
908 		mesh_aborted_resels++;
909 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
910 		mesh_flush_io(mr);
911 		udelay(1);
912 		out_8(&mr->sequence, SEQ_ENBRESEL);
913 		mesh_flush_io(mr);
914 		udelay(5);
915 		dlog(ms, "extra resel err/exc/fc = %.6x",
916 		     MKWORD(0, mr->error, mr->exception, mr->fifo_count));
917 	}
918 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
919        	mesh_flush_io(mr);
920 	udelay(1);
921 	out_8(&mr->sequence, SEQ_ENBRESEL);
922        	mesh_flush_io(mr);
923 	udelay(1);
924 	out_8(&mr->sync_params, ASYNC_PARAMS);
925 
926 	/*
927 	 * Find out who reselected us.
928 	 */
929 	if (in_8(&mr->fifo_count) == 0) {
930 		printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
931 		ms->conn_tgt = ms->host->this_id;
932 		goto bogus;
933 	}
934 	/* get the last byte in the fifo */
935 	do {
936 		b = in_8(&mr->fifo);
937 		dlog(ms, "reseldata %x", b);
938 	} while (in_8(&mr->fifo_count));
939 	for (t = 0; t < 8; ++t)
940 		if ((b & (1 << t)) != 0 && t != ms->host->this_id)
941 			break;
942 	if (b != (1 << t) + (1 << ms->host->this_id)) {
943 		printk(KERN_ERR "mesh: bad reselection data %x\n", b);
944 		ms->conn_tgt = ms->host->this_id;
945 		goto bogus;
946 	}
947 
948 
949 	/*
950 	 * Set up to continue with that target's transfer.
951 	 */
952 	ms->conn_tgt = t;
953 	tp = &ms->tgts[t];
954 	out_8(&mr->sync_params, tp->sync_params);
955 	if (ALLOW_DEBUG(t)) {
956 		printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
957 		printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
958 		       tp->saved_ptr, tp->data_goes_out, tp->current_req);
959 	}
960 	ms->current_req = tp->current_req;
961 	if (tp->current_req == NULL) {
962 		printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
963 		goto bogus;
964 	}
965 	ms->data_ptr = tp->saved_ptr;
966 	dlog(ms, "resel prev tgt=%d", prev);
967 	dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
968 	start_phase(ms);
969 	return;
970 
971 bogus:
972 	dumplog(ms, ms->conn_tgt);
973 	dumpslog(ms);
974 	ms->data_ptr = 0;
975 	ms->aborting = 1;
976 	start_phase(ms);
977 }
978 
979 static void do_abort(struct mesh_state *ms)
980 {
981 	ms->msgout[0] = ABORT;
982 	ms->n_msgout = 1;
983 	ms->aborting = 1;
984 	ms->stat = DID_ABORT;
985 	dlog(ms, "abort", 0);
986 }
987 
988 static void handle_reset(struct mesh_state *ms)
989 {
990 	int tgt;
991 	struct mesh_target *tp;
992 	struct scsi_cmnd *cmd;
993 	volatile struct mesh_regs __iomem *mr = ms->mesh;
994 
995 	for (tgt = 0; tgt < 8; ++tgt) {
996 		tp = &ms->tgts[tgt];
997 		if ((cmd = tp->current_req) != NULL) {
998 			cmd->result = DID_RESET << 16;
999 			tp->current_req = NULL;
1000 			mesh_completed(ms, cmd);
1001 		}
1002 		ms->tgts[tgt].sdtr_state = do_sdtr;
1003 		ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1004 	}
1005 	ms->current_req = NULL;
1006 	while ((cmd = ms->request_q) != NULL) {
1007 		ms->request_q = (struct scsi_cmnd *) cmd->host_scribble;
1008 		cmd->result = DID_RESET << 16;
1009 		mesh_completed(ms, cmd);
1010 	}
1011 	ms->phase = idle;
1012 	ms->msgphase = msg_none;
1013 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1014 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
1015        	mesh_flush_io(mr);
1016 	udelay(1);
1017 	out_8(&mr->sync_params, ASYNC_PARAMS);
1018 	out_8(&mr->sequence, SEQ_ENBRESEL);
1019 }
1020 
1021 static irqreturn_t do_mesh_interrupt(int irq, void *dev_id)
1022 {
1023 	unsigned long flags;
1024 	struct mesh_state *ms = dev_id;
1025 	struct Scsi_Host *dev = ms->host;
1026 
1027 	spin_lock_irqsave(dev->host_lock, flags);
1028 	mesh_interrupt(ms);
1029 	spin_unlock_irqrestore(dev->host_lock, flags);
1030 	return IRQ_HANDLED;
1031 }
1032 
1033 static void handle_error(struct mesh_state *ms)
1034 {
1035 	int err, exc, count;
1036 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1037 
1038 	err = in_8(&mr->error);
1039 	exc = in_8(&mr->exception);
1040 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1041 	dlog(ms, "error err/exc/fc/cl=%.8x",
1042 	     MKWORD(err, exc, mr->fifo_count, mr->count_lo));
1043 	if (err & ERR_SCSIRESET) {
1044 		/* SCSI bus was reset */
1045 		printk(KERN_INFO "mesh: SCSI bus reset detected: "
1046 		       "waiting for end...");
1047 		while ((in_8(&mr->bus_status1) & BS1_RST) != 0)
1048 			udelay(1);
1049 		printk("done\n");
1050 		handle_reset(ms);
1051 		/* request_q is empty, no point in mesh_start() */
1052 		return;
1053 	}
1054 	if (err & ERR_UNEXPDISC) {
1055 		/* Unexpected disconnect */
1056 		if (exc & EXC_RESELECTED) {
1057 			reselected(ms);
1058 			return;
1059 		}
1060 		if (!ms->aborting) {
1061 			printk(KERN_WARNING "mesh: target %d aborted\n",
1062 			       ms->conn_tgt);
1063 			dumplog(ms, ms->conn_tgt);
1064 			dumpslog(ms);
1065 		}
1066 		out_8(&mr->interrupt, INT_CMDDONE);
1067 		ms->stat = DID_ABORT;
1068 		mesh_done(ms, 1);
1069 		return;
1070 	}
1071 	if (err & ERR_PARITY) {
1072 		if (ms->msgphase == msg_in) {
1073 			printk(KERN_ERR "mesh: msg parity error, target %d\n",
1074 			       ms->conn_tgt);
1075 			ms->msgout[0] = MSG_PARITY_ERROR;
1076 			ms->n_msgout = 1;
1077 			ms->msgphase = msg_in_bad;
1078 			cmd_complete(ms);
1079 			return;
1080 		}
1081 		if (ms->stat == DID_OK) {
1082 			printk(KERN_ERR "mesh: parity error, target %d\n",
1083 			       ms->conn_tgt);
1084 			ms->stat = DID_PARITY;
1085 		}
1086 		count = (mr->count_hi << 8) + mr->count_lo;
1087 		if (count == 0) {
1088 			cmd_complete(ms);
1089 		} else {
1090 			/* reissue the data transfer command */
1091 			out_8(&mr->sequence, mr->sequence);
1092 		}
1093 		return;
1094 	}
1095 	if (err & ERR_SEQERR) {
1096 		if (exc & EXC_RESELECTED) {
1097 			/* This can happen if we issue a command to
1098 			   get the bus just after the target reselects us. */
1099 			static int mesh_resel_seqerr;
1100 			mesh_resel_seqerr++;
1101 			reselected(ms);
1102 			return;
1103 		}
1104 		if (exc == EXC_PHASEMM) {
1105 			static int mesh_phasemm_seqerr;
1106 			mesh_phasemm_seqerr++;
1107 			phase_mismatch(ms);
1108 			return;
1109 		}
1110 		printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
1111 		       err, exc);
1112 	} else {
1113 		printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
1114 	}
1115 	mesh_dump_regs(ms);
1116 	dumplog(ms, ms->conn_tgt);
1117 	if (ms->phase > selecting && (in_8(&mr->bus_status1) & BS1_BSY)) {
1118 		/* try to do what the target wants */
1119 		do_abort(ms);
1120 		phase_mismatch(ms);
1121 		return;
1122 	}
1123 	ms->stat = DID_ERROR;
1124 	mesh_done(ms, 1);
1125 }
1126 
1127 static void handle_exception(struct mesh_state *ms)
1128 {
1129 	int exc;
1130 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1131 
1132 	exc = in_8(&mr->exception);
1133 	out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
1134 	if (exc & EXC_RESELECTED) {
1135 		static int mesh_resel_exc;
1136 		mesh_resel_exc++;
1137 		reselected(ms);
1138 	} else if (exc == EXC_ARBLOST) {
1139 		printk(KERN_DEBUG "mesh: lost arbitration\n");
1140 		ms->stat = DID_BUS_BUSY;
1141 		mesh_done(ms, 1);
1142 	} else if (exc == EXC_SELTO) {
1143 		/* selection timed out */
1144 		ms->stat = DID_BAD_TARGET;
1145 		mesh_done(ms, 1);
1146 	} else if (exc == EXC_PHASEMM) {
1147 		/* target wants to do something different:
1148 		   find out what it wants and do it. */
1149 		phase_mismatch(ms);
1150 	} else {
1151 		printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
1152 		mesh_dump_regs(ms);
1153 		dumplog(ms, ms->conn_tgt);
1154 		do_abort(ms);
1155 		phase_mismatch(ms);
1156 	}
1157 }
1158 
1159 static void handle_msgin(struct mesh_state *ms)
1160 {
1161 	int i, code;
1162 	struct scsi_cmnd *cmd = ms->current_req;
1163 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1164 
1165 	if (ms->n_msgin == 0)
1166 		return;
1167 	code = ms->msgin[0];
1168 	if (ALLOW_DEBUG(ms->conn_tgt)) {
1169 		printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
1170 		for (i = 0; i < ms->n_msgin; ++i)
1171 			printk(" %x", ms->msgin[i]);
1172 		printk("\n");
1173 	}
1174 	dlog(ms, "msgin msg=%.8x",
1175 	     MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
1176 
1177 	ms->expect_reply = 0;
1178 	ms->n_msgout = 0;
1179 	if (ms->n_msgin < msgin_length(ms))
1180 		goto reject;
1181 	if (cmd)
1182 		cmd->SCp.Message = code;
1183 	switch (code) {
1184 	case COMMAND_COMPLETE:
1185 		break;
1186 	case EXTENDED_MESSAGE:
1187 		switch (ms->msgin[2]) {
1188 		case EXTENDED_MODIFY_DATA_POINTER:
1189 			ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
1190 				+ (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
1191 			break;
1192 		case EXTENDED_SDTR:
1193 			if (tp->sdtr_state != sdtr_sent) {
1194 				/* reply with an SDTR */
1195 				add_sdtr_msg(ms);
1196 				/* limit period to at least his value,
1197 				   offset to no more than his */
1198 				if (ms->msgout[3] < ms->msgin[3])
1199 					ms->msgout[3] = ms->msgin[3];
1200 				if (ms->msgout[4] > ms->msgin[4])
1201 					ms->msgout[4] = ms->msgin[4];
1202 				set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
1203 				ms->msgphase = msg_out;
1204 			} else {
1205 				set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
1206 			}
1207 			break;
1208 		default:
1209 			goto reject;
1210 		}
1211 		break;
1212 	case SAVE_POINTERS:
1213 		tp->saved_ptr = ms->data_ptr;
1214 		break;
1215 	case RESTORE_POINTERS:
1216 		ms->data_ptr = tp->saved_ptr;
1217 		break;
1218 	case DISCONNECT:
1219 		ms->phase = disconnecting;
1220 		break;
1221 	case ABORT:
1222 		break;
1223 	case MESSAGE_REJECT:
1224 		if (tp->sdtr_state == sdtr_sent)
1225 			set_sdtr(ms, 0, 0);
1226 		break;
1227 	case NOP:
1228 		break;
1229 	default:
1230 		if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
1231 			if (cmd == NULL) {
1232 				do_abort(ms);
1233 				ms->msgphase = msg_out;
1234 			} else if (code != cmd->device->lun + IDENTIFY_BASE) {
1235 				printk(KERN_WARNING "mesh: lun mismatch "
1236 				       "(%d != %d) on reselection from "
1237 				       "target %d\n", code - IDENTIFY_BASE,
1238 				       cmd->device->lun, ms->conn_tgt);
1239 			}
1240 			break;
1241 		}
1242 		goto reject;
1243 	}
1244 	return;
1245 
1246  reject:
1247 	printk(KERN_WARNING "mesh: rejecting message from target %d:",
1248 	       ms->conn_tgt);
1249 	for (i = 0; i < ms->n_msgin; ++i)
1250 		printk(" %x", ms->msgin[i]);
1251 	printk("\n");
1252 	ms->msgout[0] = MESSAGE_REJECT;
1253 	ms->n_msgout = 1;
1254 	ms->msgphase = msg_out;
1255 }
1256 
1257 /*
1258  * Set up DMA commands for transferring data.
1259  */
1260 static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
1261 {
1262 	int i, dma_cmd, total, off, dtot;
1263 	struct scatterlist *scl;
1264 	struct dbdma_cmd *dcmds;
1265 
1266 	dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
1267 		OUTPUT_MORE: INPUT_MORE;
1268 	dcmds = ms->dma_cmds;
1269 	dtot = 0;
1270 	if (cmd) {
1271 		int nseg;
1272 
1273 		cmd->SCp.this_residual = scsi_bufflen(cmd);
1274 
1275 		nseg = scsi_dma_map(cmd);
1276 		BUG_ON(nseg < 0);
1277 
1278 		if (nseg) {
1279 			total = 0;
1280 			off = ms->data_ptr;
1281 
1282 			scsi_for_each_sg(cmd, scl, nseg, i) {
1283 				u32 dma_addr = sg_dma_address(scl);
1284 				u32 dma_len = sg_dma_len(scl);
1285 
1286 				total += scl->length;
1287 				if (off >= dma_len) {
1288 					off -= dma_len;
1289 					continue;
1290 				}
1291 				if (dma_len > 0xffff)
1292 					panic("mesh: scatterlist element >= 64k");
1293 				st_le16(&dcmds->req_count, dma_len - off);
1294 				st_le16(&dcmds->command, dma_cmd);
1295 				st_le32(&dcmds->phy_addr, dma_addr + off);
1296 				dcmds->xfer_status = 0;
1297 				++dcmds;
1298 				dtot += dma_len - off;
1299 				off = 0;
1300 			}
1301 		}
1302 	}
1303 	if (dtot == 0) {
1304 		/* Either the target has overrun our buffer,
1305 		   or the caller didn't provide a buffer. */
1306 		static char mesh_extra_buf[64];
1307 
1308 		dtot = sizeof(mesh_extra_buf);
1309 		st_le16(&dcmds->req_count, dtot);
1310 		st_le32(&dcmds->phy_addr, virt_to_phys(mesh_extra_buf));
1311 		dcmds->xfer_status = 0;
1312 		++dcmds;
1313 	}
1314 	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
1315 	st_le16(&dcmds[-1].command, dma_cmd);
1316 	memset(dcmds, 0, sizeof(*dcmds));
1317 	st_le16(&dcmds->command, DBDMA_STOP);
1318 	ms->dma_count = dtot;
1319 }
1320 
1321 static void halt_dma(struct mesh_state *ms)
1322 {
1323 	volatile struct dbdma_regs __iomem *md = ms->dma;
1324 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1325 	struct scsi_cmnd *cmd = ms->current_req;
1326 	int t, nb;
1327 
1328 	if (!ms->tgts[ms->conn_tgt].data_goes_out) {
1329 		/* wait a little while until the fifo drains */
1330 		t = 50;
1331 		while (t > 0 && in_8(&mr->fifo_count) != 0
1332 		       && (in_le32(&md->status) & ACTIVE) != 0) {
1333 			--t;
1334 			udelay(1);
1335 		}
1336 	}
1337 	out_le32(&md->control, RUN << 16);	/* turn off RUN bit */
1338 	nb = (mr->count_hi << 8) + mr->count_lo;
1339 	dlog(ms, "halt_dma fc/count=%.6x",
1340 	     MKWORD(0, mr->fifo_count, 0, nb));
1341 	if (ms->tgts[ms->conn_tgt].data_goes_out)
1342 		nb += mr->fifo_count;
1343 	/* nb is the number of bytes not yet transferred
1344 	   to/from the target. */
1345 	ms->data_ptr -= nb;
1346 	dlog(ms, "data_ptr %x", ms->data_ptr);
1347 	if (ms->data_ptr < 0) {
1348 		printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
1349 		       ms->data_ptr, nb, ms);
1350 		ms->data_ptr = 0;
1351 #ifdef MESH_DBG
1352 		dumplog(ms, ms->conn_tgt);
1353 		dumpslog(ms);
1354 #endif /* MESH_DBG */
1355 	} else if (cmd && scsi_bufflen(cmd) &&
1356 		   ms->data_ptr > scsi_bufflen(cmd)) {
1357 		printk(KERN_DEBUG "mesh: target %d overrun, "
1358 		       "data_ptr=%x total=%x goes_out=%d\n",
1359 		       ms->conn_tgt, ms->data_ptr, scsi_bufflen(cmd),
1360 		       ms->tgts[ms->conn_tgt].data_goes_out);
1361 	}
1362 	scsi_dma_unmap(cmd);
1363 	ms->dma_started = 0;
1364 }
1365 
1366 static void phase_mismatch(struct mesh_state *ms)
1367 {
1368 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1369 	int phase;
1370 
1371 	dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
1372 	     MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
1373 	phase = in_8(&mr->bus_status0) & BS0_PHASE;
1374 	if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
1375 		/* output the last byte of the message, without ATN */
1376 		out_8(&mr->count_lo, 1);
1377 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1378 		mesh_flush_io(mr);
1379 		udelay(1);
1380 		out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1381 		ms->msgphase = msg_out_last;
1382 		return;
1383 	}
1384 
1385 	if (ms->msgphase == msg_in) {
1386 		get_msgin(ms);
1387 		if (ms->n_msgin)
1388 			handle_msgin(ms);
1389 	}
1390 
1391 	if (ms->dma_started)
1392 		halt_dma(ms);
1393 	if (mr->fifo_count) {
1394 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1395 		mesh_flush_io(mr);
1396 		udelay(1);
1397 	}
1398 
1399 	ms->msgphase = msg_none;
1400 	switch (phase) {
1401 	case BP_DATAIN:
1402 		ms->tgts[ms->conn_tgt].data_goes_out = 0;
1403 		ms->phase = dataing;
1404 		break;
1405 	case BP_DATAOUT:
1406 		ms->tgts[ms->conn_tgt].data_goes_out = 1;
1407 		ms->phase = dataing;
1408 		break;
1409 	case BP_COMMAND:
1410 		ms->phase = commanding;
1411 		break;
1412 	case BP_STATUS:
1413 		ms->phase = statusing;
1414 		break;
1415 	case BP_MSGIN:
1416 		ms->msgphase = msg_in;
1417 		ms->n_msgin = 0;
1418 		break;
1419 	case BP_MSGOUT:
1420 		ms->msgphase = msg_out;
1421 		if (ms->n_msgout == 0) {
1422 			if (ms->aborting) {
1423 				do_abort(ms);
1424 			} else {
1425 				if (ms->last_n_msgout == 0) {
1426 					printk(KERN_DEBUG
1427 					       "mesh: no msg to repeat\n");
1428 					ms->msgout[0] = NOP;
1429 					ms->last_n_msgout = 1;
1430 				}
1431 				ms->n_msgout = ms->last_n_msgout;
1432 			}
1433 		}
1434 		break;
1435 	default:
1436 		printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
1437 		ms->stat = DID_ERROR;
1438 		mesh_done(ms, 1);
1439 		return;
1440 	}
1441 
1442 	start_phase(ms);
1443 }
1444 
1445 static void cmd_complete(struct mesh_state *ms)
1446 {
1447 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1448 	struct scsi_cmnd *cmd = ms->current_req;
1449 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1450 	int seq, n, t;
1451 
1452 	dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
1453 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
1454 	switch (ms->msgphase) {
1455 	case msg_out_xxx:
1456 		/* huh?  we expected a phase mismatch */
1457 		ms->n_msgin = 0;
1458 		ms->msgphase = msg_in;
1459 		/* fall through */
1460 
1461 	case msg_in:
1462 		/* should have some message bytes in fifo */
1463 		get_msgin(ms);
1464 		n = msgin_length(ms);
1465 		if (ms->n_msgin < n) {
1466 			out_8(&mr->count_lo, n - ms->n_msgin);
1467 			out_8(&mr->sequence, SEQ_MSGIN + seq);
1468 		} else {
1469 			ms->msgphase = msg_none;
1470 			handle_msgin(ms);
1471 			start_phase(ms);
1472 		}
1473 		break;
1474 
1475 	case msg_in_bad:
1476 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1477 		mesh_flush_io(mr);
1478 		udelay(1);
1479 		out_8(&mr->count_lo, 1);
1480 		out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
1481 		break;
1482 
1483 	case msg_out:
1484 		/*
1485 		 * To get the right timing on ATN wrt ACK, we have
1486 		 * to get the MESH to drop ACK, wait until REQ gets
1487 		 * asserted, then drop ATN.  To do this we first
1488 		 * issue a SEQ_MSGOUT with ATN and wait for REQ,
1489 		 * then change the command to a SEQ_MSGOUT w/o ATN.
1490 		 * If we don't see REQ in a reasonable time, we
1491 		 * change the command to SEQ_MSGIN with ATN,
1492 		 * wait for the phase mismatch interrupt, then
1493 		 * issue the SEQ_MSGOUT without ATN.
1494 		 */
1495 		out_8(&mr->count_lo, 1);
1496 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
1497 		t = 30;		/* wait up to 30us */
1498 		while ((in_8(&mr->bus_status0) & BS0_REQ) == 0 && --t >= 0)
1499 			udelay(1);
1500 		dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
1501 		     MKWORD(mr->error, mr->exception,
1502 			    mr->fifo_count, mr->count_lo));
1503 		if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
1504 			/* whoops, target didn't do what we expected */
1505 			ms->last_n_msgout = ms->n_msgout;
1506 			ms->n_msgout = 0;
1507 			if (in_8(&mr->interrupt) & INT_ERROR) {
1508 				printk(KERN_ERR "mesh: error %x in msg_out\n",
1509 				       in_8(&mr->error));
1510 				handle_error(ms);
1511 				return;
1512 			}
1513 			if (in_8(&mr->exception) != EXC_PHASEMM)
1514 				printk(KERN_ERR "mesh: exc %x in msg_out\n",
1515 				       in_8(&mr->exception));
1516 			else
1517 				printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
1518 				       in_8(&mr->bus_status0));
1519 			handle_exception(ms);
1520 			return;
1521 		}
1522 		if (in_8(&mr->bus_status0) & BS0_REQ) {
1523 			out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1524 			mesh_flush_io(mr);
1525 			udelay(1);
1526 			out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1527 			ms->msgphase = msg_out_last;
1528 		} else {
1529 			out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
1530 			ms->msgphase = msg_out_xxx;
1531 		}
1532 		break;
1533 
1534 	case msg_out_last:
1535 		ms->last_n_msgout = ms->n_msgout;
1536 		ms->n_msgout = 0;
1537 		ms->msgphase = ms->expect_reply? msg_in: msg_none;
1538 		start_phase(ms);
1539 		break;
1540 
1541 	case msg_none:
1542 		switch (ms->phase) {
1543 		case idle:
1544 			printk(KERN_ERR "mesh: interrupt in idle phase?\n");
1545 			dumpslog(ms);
1546 			return;
1547 		case selecting:
1548 			dlog(ms, "Selecting phase at command completion",0);
1549 			ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
1550 						 (cmd? cmd->device->lun: 0));
1551 			ms->n_msgout = 1;
1552 			ms->expect_reply = 0;
1553 			if (ms->aborting) {
1554 				ms->msgout[0] = ABORT;
1555 				ms->n_msgout++;
1556 			} else if (tp->sdtr_state == do_sdtr) {
1557 				/* add SDTR message */
1558 				add_sdtr_msg(ms);
1559 				ms->expect_reply = 1;
1560 				tp->sdtr_state = sdtr_sent;
1561 			}
1562 			ms->msgphase = msg_out;
1563 			/*
1564 			 * We need to wait for REQ before dropping ATN.
1565 			 * We wait for at most 30us, then fall back to
1566 			 * a scheme where we issue a SEQ_COMMAND with ATN,
1567 			 * which will give us a phase mismatch interrupt
1568 			 * when REQ does come, and then we send the message.
1569 			 */
1570 			t = 230;		/* wait up to 230us */
1571 			while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
1572 				if (--t < 0) {
1573 					dlog(ms, "impatient for req", ms->n_msgout);
1574 					ms->msgphase = msg_none;
1575 					break;
1576 				}
1577 				udelay(1);
1578 			}
1579 			break;
1580 		case dataing:
1581 			if (ms->dma_count != 0) {
1582 				start_phase(ms);
1583 				return;
1584 			}
1585 			/*
1586 			 * We can get a phase mismatch here if the target
1587 			 * changes to the status phase, even though we have
1588 			 * had a command complete interrupt.  Then, if we
1589 			 * issue the SEQ_STATUS command, we'll get a sequence
1590 			 * error interrupt.  Which isn't so bad except that
1591 			 * occasionally the mesh actually executes the
1592 			 * SEQ_STATUS *as well as* giving us the sequence
1593 			 * error and phase mismatch exception.
1594 			 */
1595 			out_8(&mr->sequence, 0);
1596 			out_8(&mr->interrupt,
1597 			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1598 			halt_dma(ms);
1599 			break;
1600 		case statusing:
1601 			if (cmd) {
1602 				cmd->SCp.Status = mr->fifo;
1603 				if (DEBUG_TARGET(cmd))
1604 					printk(KERN_DEBUG "mesh: status is %x\n",
1605 					       cmd->SCp.Status);
1606 			}
1607 			ms->msgphase = msg_in;
1608 			break;
1609 		case busfreeing:
1610 			mesh_done(ms, 1);
1611 			return;
1612 		case disconnecting:
1613 			ms->current_req = NULL;
1614 			ms->phase = idle;
1615 			mesh_start(ms);
1616 			return;
1617 		default:
1618 			break;
1619 		}
1620 		++ms->phase;
1621 		start_phase(ms);
1622 		break;
1623 	}
1624 }
1625 
1626 
1627 /*
1628  * Called by midlayer with host locked to queue a new
1629  * request
1630  */
1631 static int mesh_queue(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
1632 {
1633 	struct mesh_state *ms;
1634 
1635 	cmd->scsi_done = done;
1636 	cmd->host_scribble = NULL;
1637 
1638 	ms = (struct mesh_state *) cmd->device->host->hostdata;
1639 
1640 	if (ms->request_q == NULL)
1641 		ms->request_q = cmd;
1642 	else
1643 		ms->request_qtail->host_scribble = (void *) cmd;
1644 	ms->request_qtail = cmd;
1645 
1646 	if (ms->phase == idle)
1647 		mesh_start(ms);
1648 
1649 	return 0;
1650 }
1651 
1652 /*
1653  * Called to handle interrupts, either call by the interrupt
1654  * handler (do_mesh_interrupt) or by other functions in
1655  * exceptional circumstances
1656  */
1657 static void mesh_interrupt(struct mesh_state *ms)
1658 {
1659 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1660 	int intr;
1661 
1662 #if 0
1663 	if (ALLOW_DEBUG(ms->conn_tgt))
1664 		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
1665 		       "phase=%d msgphase=%d\n", mr->bus_status0,
1666 		       mr->interrupt, mr->exception, mr->error,
1667 		       ms->phase, ms->msgphase);
1668 #endif
1669 	while ((intr = in_8(&mr->interrupt)) != 0) {
1670 		dlog(ms, "interrupt intr/err/exc/seq=%.8x",
1671 		     MKWORD(intr, mr->error, mr->exception, mr->sequence));
1672 		if (intr & INT_ERROR) {
1673 			handle_error(ms);
1674 		} else if (intr & INT_EXCEPTION) {
1675 			handle_exception(ms);
1676 		} else if (intr & INT_CMDDONE) {
1677 			out_8(&mr->interrupt, INT_CMDDONE);
1678 			cmd_complete(ms);
1679 		}
1680 	}
1681 }
1682 
1683 /* Todo: here we can at least try to remove the command from the
1684  * queue if it isn't connected yet, and for pending command, assert
1685  * ATN until the bus gets freed.
1686  */
1687 static int mesh_abort(struct scsi_cmnd *cmd)
1688 {
1689 	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1690 
1691 	printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
1692 	mesh_dump_regs(ms);
1693 	dumplog(ms, cmd->device->id);
1694 	dumpslog(ms);
1695 	return FAILED;
1696 }
1697 
1698 /*
1699  * Called by the midlayer with the lock held to reset the
1700  * SCSI host and bus.
1701  * The midlayer will wait for devices to come back, we don't need
1702  * to do that ourselves
1703  */
1704 static int mesh_host_reset(struct scsi_cmnd *cmd)
1705 {
1706 	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1707 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1708 	volatile struct dbdma_regs __iomem *md = ms->dma;
1709 	unsigned long flags;
1710 
1711 	printk(KERN_DEBUG "mesh_host_reset\n");
1712 
1713 	spin_lock_irqsave(ms->host->host_lock, flags);
1714 
1715 	/* Reset the controller & dbdma channel */
1716 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
1717 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
1718 	out_8(&mr->error, 0xff);	/* clear all error bits */
1719 	out_8(&mr->sequence, SEQ_RESETMESH);
1720        	mesh_flush_io(mr);
1721 	udelay(1);
1722 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1723 	out_8(&mr->source_id, ms->host->this_id);
1724 	out_8(&mr->sel_timeout, 25);	/* 250ms */
1725 	out_8(&mr->sync_params, ASYNC_PARAMS);
1726 
1727 	/* Reset the bus */
1728 	out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
1729        	mesh_flush_io(mr);
1730 	udelay(30);			/* leave it on for >= 25us */
1731 	out_8(&mr->bus_status1, 0);	/* negate RST */
1732 
1733 	/* Complete pending commands */
1734 	handle_reset(ms);
1735 
1736 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1737 	return SUCCESS;
1738 }
1739 
1740 static void set_mesh_power(struct mesh_state *ms, int state)
1741 {
1742 	if (!machine_is(powermac))
1743 		return;
1744 	if (state) {
1745 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
1746 		msleep(200);
1747 	} else {
1748 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
1749 		msleep(10);
1750 	}
1751 }
1752 
1753 
1754 #ifdef CONFIG_PM
1755 static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
1756 {
1757 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1758 	unsigned long flags;
1759 
1760 	switch (mesg.event) {
1761 	case PM_EVENT_SUSPEND:
1762 	case PM_EVENT_HIBERNATE:
1763 	case PM_EVENT_FREEZE:
1764 		break;
1765 	default:
1766 		return 0;
1767 	}
1768 	if (ms->phase == sleeping)
1769 		return 0;
1770 
1771 	scsi_block_requests(ms->host);
1772 	spin_lock_irqsave(ms->host->host_lock, flags);
1773 	while(ms->phase != idle) {
1774 		spin_unlock_irqrestore(ms->host->host_lock, flags);
1775 		msleep(10);
1776 		spin_lock_irqsave(ms->host->host_lock, flags);
1777 	}
1778 	ms->phase = sleeping;
1779 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1780 	disable_irq(ms->meshintr);
1781 	set_mesh_power(ms, 0);
1782 
1783 	return 0;
1784 }
1785 
1786 static int mesh_resume(struct macio_dev *mdev)
1787 {
1788 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1789 	unsigned long flags;
1790 
1791 	if (ms->phase != sleeping)
1792 		return 0;
1793 
1794 	set_mesh_power(ms, 1);
1795 	mesh_init(ms);
1796 	spin_lock_irqsave(ms->host->host_lock, flags);
1797 	mesh_start(ms);
1798 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1799 	enable_irq(ms->meshintr);
1800 	scsi_unblock_requests(ms->host);
1801 
1802 	return 0;
1803 }
1804 
1805 #endif /* CONFIG_PM */
1806 
1807 /*
1808  * If we leave drives set for synchronous transfers (especially
1809  * CDROMs), and reboot to MacOS, it gets confused, poor thing.
1810  * So, on reboot we reset the SCSI bus.
1811  */
1812 static int mesh_shutdown(struct macio_dev *mdev)
1813 {
1814 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1815 	volatile struct mesh_regs __iomem *mr;
1816 	unsigned long flags;
1817 
1818        	printk(KERN_INFO "resetting MESH scsi bus(es)\n");
1819 	spin_lock_irqsave(ms->host->host_lock, flags);
1820        	mr = ms->mesh;
1821 	out_8(&mr->intr_mask, 0);
1822 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1823 	out_8(&mr->bus_status1, BS1_RST);
1824 	mesh_flush_io(mr);
1825 	udelay(30);
1826 	out_8(&mr->bus_status1, 0);
1827 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1828 
1829 	return 0;
1830 }
1831 
1832 static struct scsi_host_template mesh_template = {
1833 	.proc_name			= "mesh",
1834 	.name				= "MESH",
1835 	.queuecommand			= mesh_queue,
1836 	.eh_abort_handler		= mesh_abort,
1837 	.eh_host_reset_handler		= mesh_host_reset,
1838 	.can_queue			= 20,
1839 	.this_id			= 7,
1840 	.sg_tablesize			= SG_ALL,
1841 	.cmd_per_lun			= 2,
1842 	.use_clustering			= DISABLE_CLUSTERING,
1843 };
1844 
1845 static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
1846 {
1847 	struct device_node *mesh = macio_get_of_node(mdev);
1848 	struct pci_dev* pdev = macio_get_pci_dev(mdev);
1849 	int tgt, minper;
1850 	const int *cfp;
1851 	struct mesh_state *ms;
1852 	struct Scsi_Host *mesh_host;
1853 	void *dma_cmd_space;
1854 	dma_addr_t dma_cmd_bus;
1855 
1856 	switch (mdev->bus->chip->type) {
1857 	case macio_heathrow:
1858 	case macio_gatwick:
1859 	case macio_paddington:
1860 		use_active_neg = 0;
1861 		break;
1862 	default:
1863 		use_active_neg = SEQ_ACTIVE_NEG;
1864 	}
1865 
1866 	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
1867        		printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
1868 	       	       " (got %d,%d)\n", macio_resource_count(mdev),
1869 		       macio_irq_count(mdev));
1870 		return -ENODEV;
1871 	}
1872 
1873 	if (macio_request_resources(mdev, "mesh") != 0) {
1874        		printk(KERN_ERR "mesh: unable to request memory resources");
1875 		return -EBUSY;
1876 	}
1877        	mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
1878 	if (mesh_host == NULL) {
1879 		printk(KERN_ERR "mesh: couldn't register host");
1880 		goto out_release;
1881 	}
1882 
1883 	/* Old junk for root discovery, that will die ultimately */
1884 #if !defined(MODULE)
1885        	note_scsi_host(mesh, mesh_host);
1886 #endif
1887 
1888 	mesh_host->base = macio_resource_start(mdev, 0);
1889 	mesh_host->irq = macio_irq(mdev, 0);
1890        	ms = (struct mesh_state *) mesh_host->hostdata;
1891 	macio_set_drvdata(mdev, ms);
1892 	ms->host = mesh_host;
1893 	ms->mdev = mdev;
1894 	ms->pdev = pdev;
1895 
1896 	ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
1897 	if (ms->mesh == NULL) {
1898 		printk(KERN_ERR "mesh: can't map registers\n");
1899 		goto out_free;
1900 	}
1901 	ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
1902 	if (ms->dma == NULL) {
1903 		printk(KERN_ERR "mesh: can't map registers\n");
1904 		iounmap(ms->mesh);
1905 		goto out_free;
1906 	}
1907 
1908        	ms->meshintr = macio_irq(mdev, 0);
1909        	ms->dmaintr = macio_irq(mdev, 1);
1910 
1911        	/* Space for dma command list: +1 for stop command,
1912        	 * +1 to allow for aligning.
1913 	 */
1914 	ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);
1915 
1916 	/* We use the PCI APIs for now until the generic one gets fixed
1917 	 * enough or until we get some macio-specific versions
1918 	 */
1919 	dma_cmd_space = pci_alloc_consistent(macio_get_pci_dev(mdev),
1920 					     ms->dma_cmd_size,
1921 					     &dma_cmd_bus);
1922 	if (dma_cmd_space == NULL) {
1923 		printk(KERN_ERR "mesh: can't allocate DMA table\n");
1924 		goto out_unmap;
1925 	}
1926 	memset(dma_cmd_space, 0, ms->dma_cmd_size);
1927 
1928 	ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
1929        	ms->dma_cmd_space = dma_cmd_space;
1930 	ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
1931 		- (unsigned long)dma_cmd_space;
1932 	ms->current_req = NULL;
1933        	for (tgt = 0; tgt < 8; ++tgt) {
1934 	       	ms->tgts[tgt].sdtr_state = do_sdtr;
1935 	       	ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1936 	       	ms->tgts[tgt].current_req = NULL;
1937        	}
1938 
1939 	if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
1940        		ms->clk_freq = *cfp;
1941 	else {
1942        		printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
1943 	       	ms->clk_freq = 50000000;
1944        	}
1945 
1946        	/* The maximum sync rate is clock / 5; increase
1947        	 * mesh_sync_period if necessary.
1948 	 */
1949 	minper = 1000000000 / (ms->clk_freq / 5); /* ns */
1950 	if (mesh_sync_period < minper)
1951 		mesh_sync_period = minper;
1952 
1953 	/* Power up the chip */
1954 	set_mesh_power(ms, 1);
1955 
1956 	/* Set it up */
1957        	mesh_init(ms);
1958 
1959 	/* Request interrupt */
1960        	if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
1961 	       	printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
1962 		goto out_shutdown;
1963 	}
1964 
1965 	/* Add scsi host & scan */
1966 	if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
1967 		goto out_release_irq;
1968 	scsi_scan_host(mesh_host);
1969 
1970 	return 0;
1971 
1972  out_release_irq:
1973 	free_irq(ms->meshintr, ms);
1974  out_shutdown:
1975 	/* shutdown & reset bus in case of error or macos can be confused
1976 	 * at reboot if the bus was set to synchronous mode already
1977 	 */
1978 	mesh_shutdown(mdev);
1979 	set_mesh_power(ms, 0);
1980 	pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
1981 			    ms->dma_cmd_space, ms->dma_cmd_bus);
1982  out_unmap:
1983 	iounmap(ms->dma);
1984 	iounmap(ms->mesh);
1985  out_free:
1986 	scsi_host_put(mesh_host);
1987  out_release:
1988 	macio_release_resources(mdev);
1989 
1990 	return -ENODEV;
1991 }
1992 
1993 static int mesh_remove(struct macio_dev *mdev)
1994 {
1995 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1996 	struct Scsi_Host *mesh_host = ms->host;
1997 
1998 	scsi_remove_host(mesh_host);
1999 
2000 	free_irq(ms->meshintr, ms);
2001 
2002 	/* Reset scsi bus */
2003 	mesh_shutdown(mdev);
2004 
2005 	/* Shut down chip & termination */
2006 	set_mesh_power(ms, 0);
2007 
2008 	/* Unmap registers & dma controller */
2009 	iounmap(ms->mesh);
2010        	iounmap(ms->dma);
2011 
2012 	/* Free DMA commands memory */
2013 	pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
2014 			    ms->dma_cmd_space, ms->dma_cmd_bus);
2015 
2016 	/* Release memory resources */
2017 	macio_release_resources(mdev);
2018 
2019 	scsi_host_put(mesh_host);
2020 
2021 	return 0;
2022 }
2023 
2024 
2025 static struct of_device_id mesh_match[] =
2026 {
2027 	{
2028 	.name 		= "mesh",
2029 	},
2030 	{
2031 	.type		= "scsi",
2032 	.compatible	= "chrp,mesh0"
2033 	},
2034 	{},
2035 };
2036 MODULE_DEVICE_TABLE (of, mesh_match);
2037 
2038 static struct macio_driver mesh_driver =
2039 {
2040 	.name 		= "mesh",
2041 	.match_table	= mesh_match,
2042 	.probe		= mesh_probe,
2043 	.remove		= mesh_remove,
2044 	.shutdown	= mesh_shutdown,
2045 #ifdef CONFIG_PM
2046 	.suspend	= mesh_suspend,
2047 	.resume		= mesh_resume,
2048 #endif
2049 };
2050 
2051 
2052 static int __init init_mesh(void)
2053 {
2054 
2055 	/* Calculate sync rate from module parameters */
2056 	if (sync_rate > 10)
2057 		sync_rate = 10;
2058 	if (sync_rate > 0) {
2059 		printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
2060 		mesh_sync_period = 1000 / sync_rate;	/* ns */
2061 		mesh_sync_offset = 15;
2062 	} else
2063 		printk(KERN_INFO "mesh: configured for asynchronous\n");
2064 
2065 	return macio_register_driver(&mesh_driver);
2066 }
2067 
2068 static void __exit exit_mesh(void)
2069 {
2070 	return macio_unregister_driver(&mesh_driver);
2071 }
2072 
2073 module_init(init_mesh);
2074 module_exit(exit_mesh);
2075