xref: /openbmc/linux/drivers/scsi/mesh.c (revision 7a7621df)
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/setup.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 /* Called with  meshinterrupt disabled, initialize the chipset
346  * and eventually do the initial bus reset. The lock must not be
347  * held since we can schedule.
348  */
349 static void mesh_init(struct mesh_state *ms)
350 {
351 	volatile struct mesh_regs __iomem *mr = ms->mesh;
352 	volatile struct dbdma_regs __iomem *md = ms->dma;
353 
354 	mesh_flush_io(mr);
355 	udelay(100);
356 
357 	/* Reset controller */
358 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
359 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
360 	out_8(&mr->error, 0xff);	/* clear all error bits */
361 	out_8(&mr->sequence, SEQ_RESETMESH);
362 	mesh_flush_io(mr);
363 	udelay(10);
364 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
365 	out_8(&mr->source_id, ms->host->this_id);
366 	out_8(&mr->sel_timeout, 25);	/* 250ms */
367 	out_8(&mr->sync_params, ASYNC_PARAMS);
368 
369 	if (init_reset_delay) {
370 		printk(KERN_INFO "mesh: performing initial bus reset...\n");
371 
372 		/* Reset bus */
373 		out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
374 		mesh_flush_io(mr);
375 		udelay(30);			/* leave it on for >= 25us */
376 		out_8(&mr->bus_status1, 0);	/* negate RST */
377 		mesh_flush_io(mr);
378 
379 		/* Wait for bus to come back */
380 		msleep(init_reset_delay);
381 	}
382 
383 	/* Reconfigure controller */
384 	out_8(&mr->interrupt, 0xff);	/* clear all interrupt bits */
385 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
386 	mesh_flush_io(mr);
387 	udelay(1);
388 	out_8(&mr->sync_params, ASYNC_PARAMS);
389 	out_8(&mr->sequence, SEQ_ENBRESEL);
390 
391 	ms->phase = idle;
392 	ms->msgphase = msg_none;
393 }
394 
395 
396 static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
397 {
398 	volatile struct mesh_regs __iomem *mr = ms->mesh;
399 	int t, id;
400 
401 	id = cmd->device->id;
402 	ms->current_req = cmd;
403 	ms->tgts[id].data_goes_out = cmd->sc_data_direction == DMA_TO_DEVICE;
404 	ms->tgts[id].current_req = cmd;
405 
406 #if 1
407 	if (DEBUG_TARGET(cmd)) {
408 		int i;
409 		printk(KERN_DEBUG "mesh_start: %p tgt=%d cmd=", cmd, id);
410 		for (i = 0; i < cmd->cmd_len; ++i)
411 			printk(" %x", cmd->cmnd[i]);
412 		printk(" use_sg=%d buffer=%p bufflen=%u\n",
413 		       scsi_sg_count(cmd), scsi_sglist(cmd), scsi_bufflen(cmd));
414 	}
415 #endif
416 	if (ms->dma_started)
417 		panic("mesh: double DMA start !\n");
418 
419 	ms->phase = arbitrating;
420 	ms->msgphase = msg_none;
421 	ms->data_ptr = 0;
422 	ms->dma_started = 0;
423 	ms->n_msgout = 0;
424 	ms->last_n_msgout = 0;
425 	ms->expect_reply = 0;
426 	ms->conn_tgt = id;
427 	ms->tgts[id].saved_ptr = 0;
428 	ms->stat = DID_OK;
429 	ms->aborting = 0;
430 #ifdef MESH_DBG
431 	ms->tgts[id].n_log = 0;
432 	dlog(ms, "start cmd=%x", (int) cmd);
433 #endif
434 
435 	/* Off we go */
436 	dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
437 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
438 	out_8(&mr->interrupt, INT_CMDDONE);
439 	out_8(&mr->sequence, SEQ_ENBRESEL);
440 	mesh_flush_io(mr);
441 	udelay(1);
442 
443 	if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
444 		/*
445 		 * Some other device has the bus or is arbitrating for it -
446 		 * probably a target which is about to reselect us.
447 		 */
448 		dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
449 		     MKWORD(mr->interrupt, mr->exception,
450 			    mr->error, mr->fifo_count));
451 		for (t = 100; t > 0; --t) {
452 			if ((in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) == 0)
453 				break;
454 			if (in_8(&mr->interrupt) != 0) {
455 				dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
456 				     MKWORD(mr->interrupt, mr->exception,
457 					    mr->error, mr->fifo_count));
458 				mesh_interrupt(ms);
459 				if (ms->phase != arbitrating)
460 					return;
461 			}
462 			udelay(1);
463 		}
464 		if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
465 			/* XXX should try again in a little while */
466 			ms->stat = DID_BUS_BUSY;
467 			ms->phase = idle;
468 			mesh_done(ms, 0);
469 			return;
470 		}
471 	}
472 
473 	/*
474 	 * Apparently the mesh has a bug where it will assert both its
475 	 * own bit and the target's bit on the bus during arbitration.
476 	 */
477 	out_8(&mr->dest_id, mr->source_id);
478 
479 	/*
480 	 * There appears to be a race with reselection sometimes,
481 	 * where a target reselects us just as we issue the
482 	 * arbitrate command.  It seems that then the arbitrate
483 	 * command just hangs waiting for the bus to be free
484 	 * without giving us a reselection exception.
485 	 * The only way I have found to get it to respond correctly
486 	 * is this: disable reselection before issuing the arbitrate
487 	 * command, then after issuing it, if it looks like a target
488 	 * is trying to reselect us, reset the mesh and then enable
489 	 * reselection.
490 	 */
491 	out_8(&mr->sequence, SEQ_DISRESEL);
492 	if (in_8(&mr->interrupt) != 0) {
493 		dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
494 		     MKWORD(mr->interrupt, mr->exception,
495 			    mr->error, mr->fifo_count));
496 		mesh_interrupt(ms);
497 		if (ms->phase != arbitrating)
498 			return;
499 		dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
500 		     MKWORD(mr->interrupt, mr->exception,
501 			    mr->error, mr->fifo_count));
502 	}
503 
504 	out_8(&mr->sequence, SEQ_ARBITRATE);
505 
506 	for (t = 230; t > 0; --t) {
507 		if (in_8(&mr->interrupt) != 0)
508 			break;
509 		udelay(1);
510 	}
511 	dlog(ms, "after arb, intr/exc/err/fc=%.8x",
512 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
513 	if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
514 	    && (in_8(&mr->bus_status0) & BS0_IO)) {
515 		/* looks like a reselection - try resetting the mesh */
516 		dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
517 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
518 		out_8(&mr->sequence, SEQ_RESETMESH);
519 		mesh_flush_io(mr);
520 		udelay(10);
521 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
522 		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
523 		out_8(&mr->sequence, SEQ_ENBRESEL);
524 		mesh_flush_io(mr);
525 		for (t = 10; t > 0 && in_8(&mr->interrupt) == 0; --t)
526 			udelay(1);
527 		dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
528 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
529 #ifndef MESH_MULTIPLE_HOSTS
530 		if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
531 		    && (in_8(&mr->bus_status0) & BS0_IO)) {
532 			printk(KERN_ERR "mesh: controller not responding"
533 			       " to reselection!\n");
534 			/*
535 			 * If this is a target reselecting us, and the
536 			 * mesh isn't responding, the higher levels of
537 			 * the scsi code will eventually time out and
538 			 * reset the bus.
539 			 */
540 		}
541 #endif
542 	}
543 }
544 
545 /*
546  * Start the next command for a MESH.
547  * Should be called with interrupts disabled.
548  */
549 static void mesh_start(struct mesh_state *ms)
550 {
551 	struct scsi_cmnd *cmd, *prev, *next;
552 
553 	if (ms->phase != idle || ms->current_req != NULL) {
554 		printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
555 		       ms->phase, ms);
556 		return;
557 	}
558 
559 	while (ms->phase == idle) {
560 		prev = NULL;
561 		for (cmd = ms->request_q; ; cmd = (struct scsi_cmnd *) cmd->host_scribble) {
562 			if (cmd == NULL)
563 				return;
564 			if (ms->tgts[cmd->device->id].current_req == NULL)
565 				break;
566 			prev = cmd;
567 		}
568 		next = (struct scsi_cmnd *) cmd->host_scribble;
569 		if (prev == NULL)
570 			ms->request_q = next;
571 		else
572 			prev->host_scribble = (void *) next;
573 		if (next == NULL)
574 			ms->request_qtail = prev;
575 
576 		mesh_start_cmd(ms, cmd);
577 	}
578 }
579 
580 static void mesh_done(struct mesh_state *ms, int start_next)
581 {
582 	struct scsi_cmnd *cmd;
583 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
584 
585 	cmd = ms->current_req;
586 	ms->current_req = NULL;
587 	tp->current_req = NULL;
588 	if (cmd) {
589 		struct mesh_cmd_priv *mcmd = mesh_priv(cmd);
590 
591 		set_host_byte(cmd, ms->stat);
592 		set_status_byte(cmd, mcmd->status);
593 		if (ms->stat == DID_OK)
594 			scsi_msg_to_host_byte(cmd, mcmd->message);
595 		if (DEBUG_TARGET(cmd)) {
596 			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
597 			       cmd->result, ms->data_ptr, scsi_bufflen(cmd));
598 #if 0
599 			/* needs to use sg? */
600 			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
601 			    && cmd->request_buffer != 0) {
602 				unsigned char *b = cmd->request_buffer;
603 				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
604 				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
605 			}
606 #endif
607 		}
608 		mcmd->this_residual -= ms->data_ptr;
609 		scsi_done(cmd);
610 	}
611 	if (start_next) {
612 		out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
613 		mesh_flush_io(ms->mesh);
614 		udelay(1);
615 		ms->phase = idle;
616 		mesh_start(ms);
617 	}
618 }
619 
620 static inline void add_sdtr_msg(struct mesh_state *ms)
621 {
622 	int i = ms->n_msgout;
623 
624 	ms->msgout[i] = EXTENDED_MESSAGE;
625 	ms->msgout[i+1] = 3;
626 	ms->msgout[i+2] = EXTENDED_SDTR;
627 	ms->msgout[i+3] = mesh_sync_period/4;
628 	ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
629 	ms->n_msgout = i + 5;
630 }
631 
632 static void set_sdtr(struct mesh_state *ms, int period, int offset)
633 {
634 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
635 	volatile struct mesh_regs __iomem *mr = ms->mesh;
636 	int v, tr;
637 
638 	tp->sdtr_state = sdtr_done;
639 	if (offset == 0) {
640 		/* asynchronous */
641 		if (SYNC_OFF(tp->sync_params))
642 			printk(KERN_INFO "mesh: target %d now asynchronous\n",
643 			       ms->conn_tgt);
644 		tp->sync_params = ASYNC_PARAMS;
645 		out_8(&mr->sync_params, ASYNC_PARAMS);
646 		return;
647 	}
648 	/*
649 	 * We need to compute ceil(clk_freq * period / 500e6) - 2
650 	 * without incurring overflow.
651 	 */
652 	v = (ms->clk_freq / 5000) * period;
653 	if (v <= 250000) {
654 		/* special case: sync_period == 5 * clk_period */
655 		v = 0;
656 		/* units of tr are 100kB/s */
657 		tr = (ms->clk_freq + 250000) / 500000;
658 	} else {
659 		/* sync_period == (v + 2) * 2 * clk_period */
660 		v = (v + 99999) / 100000 - 2;
661 		if (v > 15)
662 			v = 15;	/* oops */
663 		tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
664 	}
665 	if (offset > 15)
666 		offset = 15;	/* can't happen */
667 	tp->sync_params = SYNC_PARAMS(offset, v);
668 	out_8(&mr->sync_params, tp->sync_params);
669 	printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
670 	       ms->conn_tgt, tr/10, tr%10);
671 }
672 
673 static void start_phase(struct mesh_state *ms)
674 {
675 	int i, seq, nb;
676 	volatile struct mesh_regs __iomem *mr = ms->mesh;
677 	volatile struct dbdma_regs __iomem *md = ms->dma;
678 	struct scsi_cmnd *cmd = ms->current_req;
679 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
680 
681 	dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
682 	     MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
683 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
684 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
685 	switch (ms->msgphase) {
686 	case msg_none:
687 		break;
688 
689 	case msg_in:
690 		out_8(&mr->count_hi, 0);
691 		out_8(&mr->count_lo, 1);
692 		out_8(&mr->sequence, SEQ_MSGIN + seq);
693 		ms->n_msgin = 0;
694 		return;
695 
696 	case msg_out:
697 		/*
698 		 * To make sure ATN drops before we assert ACK for
699 		 * the last byte of the message, we have to do the
700 		 * last byte specially.
701 		 */
702 		if (ms->n_msgout <= 0) {
703 			printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
704 			       ms->n_msgout);
705 			mesh_dump_regs(ms);
706 			ms->msgphase = msg_none;
707 			break;
708 		}
709 		if (ALLOW_DEBUG(ms->conn_tgt)) {
710 			printk(KERN_DEBUG "mesh: sending %d msg bytes:",
711 			       ms->n_msgout);
712 			for (i = 0; i < ms->n_msgout; ++i)
713 				printk(" %x", ms->msgout[i]);
714 			printk("\n");
715 		}
716 		dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
717 						ms->msgout[1], ms->msgout[2]));
718 		out_8(&mr->count_hi, 0);
719 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
720 		mesh_flush_io(mr);
721 		udelay(1);
722 		/*
723 		 * If ATN is not already asserted, we assert it, then
724 		 * issue a SEQ_MSGOUT to get the mesh to drop ACK.
725 		 */
726 		if ((in_8(&mr->bus_status0) & BS0_ATN) == 0) {
727 			dlog(ms, "bus0 was %.2x explicitly asserting ATN", mr->bus_status0);
728 			out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
729 			mesh_flush_io(mr);
730 			udelay(1);
731 			out_8(&mr->count_lo, 1);
732 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
733 			out_8(&mr->bus_status0, 0); /* release explicit ATN */
734 			dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
735 		}
736 		if (ms->n_msgout == 1) {
737 			/*
738 			 * We can't issue the SEQ_MSGOUT without ATN
739 			 * until the target has asserted REQ.  The logic
740 			 * in cmd_complete handles both situations:
741 			 * REQ already asserted or not.
742 			 */
743 			cmd_complete(ms);
744 		} else {
745 			out_8(&mr->count_lo, ms->n_msgout - 1);
746 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
747 			for (i = 0; i < ms->n_msgout - 1; ++i)
748 				out_8(&mr->fifo, ms->msgout[i]);
749 		}
750 		return;
751 
752 	default:
753 		printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
754 		       ms->msgphase);
755 	}
756 
757 	switch (ms->phase) {
758 	case selecting:
759 		out_8(&mr->dest_id, ms->conn_tgt);
760 		out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
761 		break;
762 	case commanding:
763 		out_8(&mr->sync_params, tp->sync_params);
764 		out_8(&mr->count_hi, 0);
765 		if (cmd) {
766 			out_8(&mr->count_lo, cmd->cmd_len);
767 			out_8(&mr->sequence, SEQ_COMMAND + seq);
768 			for (i = 0; i < cmd->cmd_len; ++i)
769 				out_8(&mr->fifo, cmd->cmnd[i]);
770 		} else {
771 			out_8(&mr->count_lo, 6);
772 			out_8(&mr->sequence, SEQ_COMMAND + seq);
773 			for (i = 0; i < 6; ++i)
774 				out_8(&mr->fifo, 0);
775 		}
776 		break;
777 	case dataing:
778 		/* transfer data, if any */
779 		if (!ms->dma_started) {
780 			set_dma_cmds(ms, cmd);
781 			out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
782 			out_le32(&md->control, (RUN << 16) | RUN);
783 			ms->dma_started = 1;
784 		}
785 		nb = ms->dma_count;
786 		if (nb > 0xfff0)
787 			nb = 0xfff0;
788 		ms->dma_count -= nb;
789 		ms->data_ptr += nb;
790 		out_8(&mr->count_lo, nb);
791 		out_8(&mr->count_hi, nb >> 8);
792 		out_8(&mr->sequence, (tp->data_goes_out?
793 				SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
794 		break;
795 	case statusing:
796 		out_8(&mr->count_hi, 0);
797 		out_8(&mr->count_lo, 1);
798 		out_8(&mr->sequence, SEQ_STATUS + seq);
799 		break;
800 	case busfreeing:
801 	case disconnecting:
802 		out_8(&mr->sequence, SEQ_ENBRESEL);
803 		mesh_flush_io(mr);
804 		udelay(1);
805 		dlog(ms, "enbresel intr/exc/err/fc=%.8x",
806 		     MKWORD(mr->interrupt, mr->exception, mr->error,
807 			    mr->fifo_count));
808 		out_8(&mr->sequence, SEQ_BUSFREE);
809 		break;
810 	default:
811 		printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
812 		       ms->phase);
813 		dumpslog(ms);
814 	}
815 
816 }
817 
818 static inline void get_msgin(struct mesh_state *ms)
819 {
820 	volatile struct mesh_regs __iomem *mr = ms->mesh;
821 	int i, n;
822 
823 	n = mr->fifo_count;
824 	if (n != 0) {
825 		i = ms->n_msgin;
826 		ms->n_msgin = i + n;
827 		for (; n > 0; --n)
828 			ms->msgin[i++] = in_8(&mr->fifo);
829 	}
830 }
831 
832 static inline int msgin_length(struct mesh_state *ms)
833 {
834 	int b, n;
835 
836 	n = 1;
837 	if (ms->n_msgin > 0) {
838 		b = ms->msgin[0];
839 		if (b == 1) {
840 			/* extended message */
841 			n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
842 		} else if (0x20 <= b && b <= 0x2f) {
843 			/* 2-byte message */
844 			n = 2;
845 		}
846 	}
847 	return n;
848 }
849 
850 static void reselected(struct mesh_state *ms)
851 {
852 	volatile struct mesh_regs __iomem *mr = ms->mesh;
853 	struct scsi_cmnd *cmd;
854 	struct mesh_target *tp;
855 	int b, t, prev;
856 
857 	switch (ms->phase) {
858 	case idle:
859 		break;
860 	case arbitrating:
861 		if ((cmd = ms->current_req) != NULL) {
862 			/* put the command back on the queue */
863 			cmd->host_scribble = (void *) ms->request_q;
864 			if (ms->request_q == NULL)
865 				ms->request_qtail = cmd;
866 			ms->request_q = cmd;
867 			tp = &ms->tgts[cmd->device->id];
868 			tp->current_req = NULL;
869 		}
870 		break;
871 	case busfreeing:
872 		ms->phase = reselecting;
873 		mesh_done(ms, 0);
874 		break;
875 	case disconnecting:
876 		break;
877 	default:
878 		printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
879 		       ms->msgphase, ms->phase, ms->conn_tgt);
880 		dumplog(ms, ms->conn_tgt);
881 		dumpslog(ms);
882 	}
883 
884 	if (ms->dma_started) {
885 		printk(KERN_ERR "mesh: reselected with DMA started !\n");
886 		halt_dma(ms);
887 	}
888 	ms->current_req = NULL;
889 	ms->phase = dataing;
890 	ms->msgphase = msg_in;
891 	ms->n_msgout = 0;
892 	ms->last_n_msgout = 0;
893 	prev = ms->conn_tgt;
894 
895 	/*
896 	 * We seem to get abortive reselections sometimes.
897 	 */
898 	while ((in_8(&mr->bus_status1) & BS1_BSY) == 0) {
899 		static int mesh_aborted_resels;
900 		mesh_aborted_resels++;
901 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
902 		mesh_flush_io(mr);
903 		udelay(1);
904 		out_8(&mr->sequence, SEQ_ENBRESEL);
905 		mesh_flush_io(mr);
906 		udelay(5);
907 		dlog(ms, "extra resel err/exc/fc = %.6x",
908 		     MKWORD(0, mr->error, mr->exception, mr->fifo_count));
909 	}
910 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
911        	mesh_flush_io(mr);
912 	udelay(1);
913 	out_8(&mr->sequence, SEQ_ENBRESEL);
914        	mesh_flush_io(mr);
915 	udelay(1);
916 	out_8(&mr->sync_params, ASYNC_PARAMS);
917 
918 	/*
919 	 * Find out who reselected us.
920 	 */
921 	if (in_8(&mr->fifo_count) == 0) {
922 		printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
923 		ms->conn_tgt = ms->host->this_id;
924 		goto bogus;
925 	}
926 	/* get the last byte in the fifo */
927 	do {
928 		b = in_8(&mr->fifo);
929 		dlog(ms, "reseldata %x", b);
930 	} while (in_8(&mr->fifo_count));
931 	for (t = 0; t < 8; ++t)
932 		if ((b & (1 << t)) != 0 && t != ms->host->this_id)
933 			break;
934 	if (b != (1 << t) + (1 << ms->host->this_id)) {
935 		printk(KERN_ERR "mesh: bad reselection data %x\n", b);
936 		ms->conn_tgt = ms->host->this_id;
937 		goto bogus;
938 	}
939 
940 
941 	/*
942 	 * Set up to continue with that target's transfer.
943 	 */
944 	ms->conn_tgt = t;
945 	tp = &ms->tgts[t];
946 	out_8(&mr->sync_params, tp->sync_params);
947 	if (ALLOW_DEBUG(t)) {
948 		printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
949 		printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
950 		       tp->saved_ptr, tp->data_goes_out, tp->current_req);
951 	}
952 	ms->current_req = tp->current_req;
953 	if (tp->current_req == NULL) {
954 		printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
955 		goto bogus;
956 	}
957 	ms->data_ptr = tp->saved_ptr;
958 	dlog(ms, "resel prev tgt=%d", prev);
959 	dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
960 	start_phase(ms);
961 	return;
962 
963 bogus:
964 	dumplog(ms, ms->conn_tgt);
965 	dumpslog(ms);
966 	ms->data_ptr = 0;
967 	ms->aborting = 1;
968 	start_phase(ms);
969 }
970 
971 static void do_abort(struct mesh_state *ms)
972 {
973 	ms->msgout[0] = ABORT;
974 	ms->n_msgout = 1;
975 	ms->aborting = 1;
976 	ms->stat = DID_ABORT;
977 	dlog(ms, "abort", 0);
978 }
979 
980 static void handle_reset(struct mesh_state *ms)
981 {
982 	int tgt;
983 	struct mesh_target *tp;
984 	struct scsi_cmnd *cmd;
985 	volatile struct mesh_regs __iomem *mr = ms->mesh;
986 
987 	for (tgt = 0; tgt < 8; ++tgt) {
988 		tp = &ms->tgts[tgt];
989 		if ((cmd = tp->current_req) != NULL) {
990 			set_host_byte(cmd, DID_RESET);
991 			tp->current_req = NULL;
992 			scsi_done(cmd);
993 		}
994 		ms->tgts[tgt].sdtr_state = do_sdtr;
995 		ms->tgts[tgt].sync_params = ASYNC_PARAMS;
996 	}
997 	ms->current_req = NULL;
998 	while ((cmd = ms->request_q) != NULL) {
999 		ms->request_q = (struct scsi_cmnd *) cmd->host_scribble;
1000 		set_host_byte(cmd, DID_RESET);
1001 		scsi_done(cmd);
1002 	}
1003 	ms->phase = idle;
1004 	ms->msgphase = msg_none;
1005 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1006 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
1007        	mesh_flush_io(mr);
1008 	udelay(1);
1009 	out_8(&mr->sync_params, ASYNC_PARAMS);
1010 	out_8(&mr->sequence, SEQ_ENBRESEL);
1011 }
1012 
1013 static irqreturn_t do_mesh_interrupt(int irq, void *dev_id)
1014 {
1015 	unsigned long flags;
1016 	struct mesh_state *ms = dev_id;
1017 	struct Scsi_Host *dev = ms->host;
1018 
1019 	spin_lock_irqsave(dev->host_lock, flags);
1020 	mesh_interrupt(ms);
1021 	spin_unlock_irqrestore(dev->host_lock, flags);
1022 	return IRQ_HANDLED;
1023 }
1024 
1025 static void handle_error(struct mesh_state *ms)
1026 {
1027 	int err, exc, count;
1028 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1029 
1030 	err = in_8(&mr->error);
1031 	exc = in_8(&mr->exception);
1032 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1033 	dlog(ms, "error err/exc/fc/cl=%.8x",
1034 	     MKWORD(err, exc, mr->fifo_count, mr->count_lo));
1035 	if (err & ERR_SCSIRESET) {
1036 		/* SCSI bus was reset */
1037 		printk(KERN_INFO "mesh: SCSI bus reset detected: "
1038 		       "waiting for end...");
1039 		while ((in_8(&mr->bus_status1) & BS1_RST) != 0)
1040 			udelay(1);
1041 		printk("done\n");
1042 		if (ms->dma_started)
1043 			halt_dma(ms);
1044 		handle_reset(ms);
1045 		/* request_q is empty, no point in mesh_start() */
1046 		return;
1047 	}
1048 	if (err & ERR_UNEXPDISC) {
1049 		/* Unexpected disconnect */
1050 		if (exc & EXC_RESELECTED) {
1051 			reselected(ms);
1052 			return;
1053 		}
1054 		if (!ms->aborting) {
1055 			printk(KERN_WARNING "mesh: target %d aborted\n",
1056 			       ms->conn_tgt);
1057 			dumplog(ms, ms->conn_tgt);
1058 			dumpslog(ms);
1059 		}
1060 		out_8(&mr->interrupt, INT_CMDDONE);
1061 		ms->stat = DID_ABORT;
1062 		mesh_done(ms, 1);
1063 		return;
1064 	}
1065 	if (err & ERR_PARITY) {
1066 		if (ms->msgphase == msg_in) {
1067 			printk(KERN_ERR "mesh: msg parity error, target %d\n",
1068 			       ms->conn_tgt);
1069 			ms->msgout[0] = MSG_PARITY_ERROR;
1070 			ms->n_msgout = 1;
1071 			ms->msgphase = msg_in_bad;
1072 			cmd_complete(ms);
1073 			return;
1074 		}
1075 		if (ms->stat == DID_OK) {
1076 			printk(KERN_ERR "mesh: parity error, target %d\n",
1077 			       ms->conn_tgt);
1078 			ms->stat = DID_PARITY;
1079 		}
1080 		count = (mr->count_hi << 8) + mr->count_lo;
1081 		if (count == 0) {
1082 			cmd_complete(ms);
1083 		} else {
1084 			/* reissue the data transfer command */
1085 			out_8(&mr->sequence, mr->sequence);
1086 		}
1087 		return;
1088 	}
1089 	if (err & ERR_SEQERR) {
1090 		if (exc & EXC_RESELECTED) {
1091 			/* This can happen if we issue a command to
1092 			   get the bus just after the target reselects us. */
1093 			static int mesh_resel_seqerr;
1094 			mesh_resel_seqerr++;
1095 			reselected(ms);
1096 			return;
1097 		}
1098 		if (exc == EXC_PHASEMM) {
1099 			static int mesh_phasemm_seqerr;
1100 			mesh_phasemm_seqerr++;
1101 			phase_mismatch(ms);
1102 			return;
1103 		}
1104 		printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
1105 		       err, exc);
1106 	} else {
1107 		printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
1108 	}
1109 	mesh_dump_regs(ms);
1110 	dumplog(ms, ms->conn_tgt);
1111 	if (ms->phase > selecting && (in_8(&mr->bus_status1) & BS1_BSY)) {
1112 		/* try to do what the target wants */
1113 		do_abort(ms);
1114 		phase_mismatch(ms);
1115 		return;
1116 	}
1117 	ms->stat = DID_ERROR;
1118 	mesh_done(ms, 1);
1119 }
1120 
1121 static void handle_exception(struct mesh_state *ms)
1122 {
1123 	int exc;
1124 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1125 
1126 	exc = in_8(&mr->exception);
1127 	out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
1128 	if (exc & EXC_RESELECTED) {
1129 		static int mesh_resel_exc;
1130 		mesh_resel_exc++;
1131 		reselected(ms);
1132 	} else if (exc == EXC_ARBLOST) {
1133 		printk(KERN_DEBUG "mesh: lost arbitration\n");
1134 		ms->stat = DID_BUS_BUSY;
1135 		mesh_done(ms, 1);
1136 	} else if (exc == EXC_SELTO) {
1137 		/* selection timed out */
1138 		ms->stat = DID_BAD_TARGET;
1139 		mesh_done(ms, 1);
1140 	} else if (exc == EXC_PHASEMM) {
1141 		/* target wants to do something different:
1142 		   find out what it wants and do it. */
1143 		phase_mismatch(ms);
1144 	} else {
1145 		printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
1146 		mesh_dump_regs(ms);
1147 		dumplog(ms, ms->conn_tgt);
1148 		do_abort(ms);
1149 		phase_mismatch(ms);
1150 	}
1151 }
1152 
1153 static void handle_msgin(struct mesh_state *ms)
1154 {
1155 	int i, code;
1156 	struct scsi_cmnd *cmd = ms->current_req;
1157 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1158 
1159 	if (ms->n_msgin == 0)
1160 		return;
1161 	code = ms->msgin[0];
1162 	if (ALLOW_DEBUG(ms->conn_tgt)) {
1163 		printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
1164 		for (i = 0; i < ms->n_msgin; ++i)
1165 			printk(" %x", ms->msgin[i]);
1166 		printk("\n");
1167 	}
1168 	dlog(ms, "msgin msg=%.8x",
1169 	     MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
1170 
1171 	ms->expect_reply = 0;
1172 	ms->n_msgout = 0;
1173 	if (ms->n_msgin < msgin_length(ms))
1174 		goto reject;
1175 	if (cmd)
1176 		mesh_priv(cmd)->message = code;
1177 	switch (code) {
1178 	case COMMAND_COMPLETE:
1179 		break;
1180 	case EXTENDED_MESSAGE:
1181 		switch (ms->msgin[2]) {
1182 		case EXTENDED_MODIFY_DATA_POINTER:
1183 			ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
1184 				+ (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
1185 			break;
1186 		case EXTENDED_SDTR:
1187 			if (tp->sdtr_state != sdtr_sent) {
1188 				/* reply with an SDTR */
1189 				add_sdtr_msg(ms);
1190 				/* limit period to at least his value,
1191 				   offset to no more than his */
1192 				if (ms->msgout[3] < ms->msgin[3])
1193 					ms->msgout[3] = ms->msgin[3];
1194 				if (ms->msgout[4] > ms->msgin[4])
1195 					ms->msgout[4] = ms->msgin[4];
1196 				set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
1197 				ms->msgphase = msg_out;
1198 			} else {
1199 				set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
1200 			}
1201 			break;
1202 		default:
1203 			goto reject;
1204 		}
1205 		break;
1206 	case SAVE_POINTERS:
1207 		tp->saved_ptr = ms->data_ptr;
1208 		break;
1209 	case RESTORE_POINTERS:
1210 		ms->data_ptr = tp->saved_ptr;
1211 		break;
1212 	case DISCONNECT:
1213 		ms->phase = disconnecting;
1214 		break;
1215 	case ABORT:
1216 		break;
1217 	case MESSAGE_REJECT:
1218 		if (tp->sdtr_state == sdtr_sent)
1219 			set_sdtr(ms, 0, 0);
1220 		break;
1221 	case NOP:
1222 		break;
1223 	default:
1224 		if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
1225 			if (cmd == NULL) {
1226 				do_abort(ms);
1227 				ms->msgphase = msg_out;
1228 			} else if (code != cmd->device->lun + IDENTIFY_BASE) {
1229 				printk(KERN_WARNING "mesh: lun mismatch "
1230 				       "(%d != %llu) on reselection from "
1231 				       "target %d\n", code - IDENTIFY_BASE,
1232 				       cmd->device->lun, ms->conn_tgt);
1233 			}
1234 			break;
1235 		}
1236 		goto reject;
1237 	}
1238 	return;
1239 
1240  reject:
1241 	printk(KERN_WARNING "mesh: rejecting message from target %d:",
1242 	       ms->conn_tgt);
1243 	for (i = 0; i < ms->n_msgin; ++i)
1244 		printk(" %x", ms->msgin[i]);
1245 	printk("\n");
1246 	ms->msgout[0] = MESSAGE_REJECT;
1247 	ms->n_msgout = 1;
1248 	ms->msgphase = msg_out;
1249 }
1250 
1251 /*
1252  * Set up DMA commands for transferring data.
1253  */
1254 static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
1255 {
1256 	int i, dma_cmd, total, off, dtot;
1257 	struct scatterlist *scl;
1258 	struct dbdma_cmd *dcmds;
1259 
1260 	dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
1261 		OUTPUT_MORE: INPUT_MORE;
1262 	dcmds = ms->dma_cmds;
1263 	dtot = 0;
1264 	if (cmd) {
1265 		int nseg;
1266 
1267 		mesh_priv(cmd)->this_residual = scsi_bufflen(cmd);
1268 
1269 		nseg = scsi_dma_map(cmd);
1270 		BUG_ON(nseg < 0);
1271 
1272 		if (nseg) {
1273 			total = 0;
1274 			off = ms->data_ptr;
1275 
1276 			scsi_for_each_sg(cmd, scl, nseg, i) {
1277 				u32 dma_addr = sg_dma_address(scl);
1278 				u32 dma_len = sg_dma_len(scl);
1279 
1280 				total += scl->length;
1281 				if (off >= dma_len) {
1282 					off -= dma_len;
1283 					continue;
1284 				}
1285 				if (dma_len > 0xffff)
1286 					panic("mesh: scatterlist element >= 64k");
1287 				dcmds->req_count = cpu_to_le16(dma_len - off);
1288 				dcmds->command = cpu_to_le16(dma_cmd);
1289 				dcmds->phy_addr = cpu_to_le32(dma_addr + off);
1290 				dcmds->xfer_status = 0;
1291 				++dcmds;
1292 				dtot += dma_len - off;
1293 				off = 0;
1294 			}
1295 		}
1296 	}
1297 	if (dtot == 0) {
1298 		/* Either the target has overrun our buffer,
1299 		   or the caller didn't provide a buffer. */
1300 		static char mesh_extra_buf[64];
1301 
1302 		dtot = sizeof(mesh_extra_buf);
1303 		dcmds->req_count = cpu_to_le16(dtot);
1304 		dcmds->phy_addr = cpu_to_le32(virt_to_phys(mesh_extra_buf));
1305 		dcmds->xfer_status = 0;
1306 		++dcmds;
1307 	}
1308 	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
1309 	dcmds[-1].command = cpu_to_le16(dma_cmd);
1310 	memset(dcmds, 0, sizeof(*dcmds));
1311 	dcmds->command = cpu_to_le16(DBDMA_STOP);
1312 	ms->dma_count = dtot;
1313 }
1314 
1315 static void halt_dma(struct mesh_state *ms)
1316 {
1317 	volatile struct dbdma_regs __iomem *md = ms->dma;
1318 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1319 	struct scsi_cmnd *cmd = ms->current_req;
1320 	int t, nb;
1321 
1322 	if (!ms->tgts[ms->conn_tgt].data_goes_out) {
1323 		/* wait a little while until the fifo drains */
1324 		t = 50;
1325 		while (t > 0 && in_8(&mr->fifo_count) != 0
1326 		       && (in_le32(&md->status) & ACTIVE) != 0) {
1327 			--t;
1328 			udelay(1);
1329 		}
1330 	}
1331 	out_le32(&md->control, RUN << 16);	/* turn off RUN bit */
1332 	nb = (mr->count_hi << 8) + mr->count_lo;
1333 	dlog(ms, "halt_dma fc/count=%.6x",
1334 	     MKWORD(0, mr->fifo_count, 0, nb));
1335 	if (ms->tgts[ms->conn_tgt].data_goes_out)
1336 		nb += mr->fifo_count;
1337 	/* nb is the number of bytes not yet transferred
1338 	   to/from the target. */
1339 	ms->data_ptr -= nb;
1340 	dlog(ms, "data_ptr %x", ms->data_ptr);
1341 	if (ms->data_ptr < 0) {
1342 		printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
1343 		       ms->data_ptr, nb, ms);
1344 		ms->data_ptr = 0;
1345 #ifdef MESH_DBG
1346 		dumplog(ms, ms->conn_tgt);
1347 		dumpslog(ms);
1348 #endif /* MESH_DBG */
1349 	} else if (cmd && scsi_bufflen(cmd) &&
1350 		   ms->data_ptr > scsi_bufflen(cmd)) {
1351 		printk(KERN_DEBUG "mesh: target %d overrun, "
1352 		       "data_ptr=%x total=%x goes_out=%d\n",
1353 		       ms->conn_tgt, ms->data_ptr, scsi_bufflen(cmd),
1354 		       ms->tgts[ms->conn_tgt].data_goes_out);
1355 	}
1356 	if (cmd)
1357 		scsi_dma_unmap(cmd);
1358 	ms->dma_started = 0;
1359 }
1360 
1361 static void phase_mismatch(struct mesh_state *ms)
1362 {
1363 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1364 	int phase;
1365 
1366 	dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
1367 	     MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
1368 	phase = in_8(&mr->bus_status0) & BS0_PHASE;
1369 	if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
1370 		/* output the last byte of the message, without ATN */
1371 		out_8(&mr->count_lo, 1);
1372 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1373 		mesh_flush_io(mr);
1374 		udelay(1);
1375 		out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1376 		ms->msgphase = msg_out_last;
1377 		return;
1378 	}
1379 
1380 	if (ms->msgphase == msg_in) {
1381 		get_msgin(ms);
1382 		if (ms->n_msgin)
1383 			handle_msgin(ms);
1384 	}
1385 
1386 	if (ms->dma_started)
1387 		halt_dma(ms);
1388 	if (mr->fifo_count) {
1389 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1390 		mesh_flush_io(mr);
1391 		udelay(1);
1392 	}
1393 
1394 	ms->msgphase = msg_none;
1395 	switch (phase) {
1396 	case BP_DATAIN:
1397 		ms->tgts[ms->conn_tgt].data_goes_out = 0;
1398 		ms->phase = dataing;
1399 		break;
1400 	case BP_DATAOUT:
1401 		ms->tgts[ms->conn_tgt].data_goes_out = 1;
1402 		ms->phase = dataing;
1403 		break;
1404 	case BP_COMMAND:
1405 		ms->phase = commanding;
1406 		break;
1407 	case BP_STATUS:
1408 		ms->phase = statusing;
1409 		break;
1410 	case BP_MSGIN:
1411 		ms->msgphase = msg_in;
1412 		ms->n_msgin = 0;
1413 		break;
1414 	case BP_MSGOUT:
1415 		ms->msgphase = msg_out;
1416 		if (ms->n_msgout == 0) {
1417 			if (ms->aborting) {
1418 				do_abort(ms);
1419 			} else {
1420 				if (ms->last_n_msgout == 0) {
1421 					printk(KERN_DEBUG
1422 					       "mesh: no msg to repeat\n");
1423 					ms->msgout[0] = NOP;
1424 					ms->last_n_msgout = 1;
1425 				}
1426 				ms->n_msgout = ms->last_n_msgout;
1427 			}
1428 		}
1429 		break;
1430 	default:
1431 		printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
1432 		ms->stat = DID_ERROR;
1433 		mesh_done(ms, 1);
1434 		return;
1435 	}
1436 
1437 	start_phase(ms);
1438 }
1439 
1440 static void cmd_complete(struct mesh_state *ms)
1441 {
1442 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1443 	struct scsi_cmnd *cmd = ms->current_req;
1444 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1445 	int seq, n, t;
1446 
1447 	dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
1448 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
1449 	switch (ms->msgphase) {
1450 	case msg_out_xxx:
1451 		/* huh?  we expected a phase mismatch */
1452 		ms->n_msgin = 0;
1453 		ms->msgphase = msg_in;
1454 		fallthrough;
1455 
1456 	case msg_in:
1457 		/* should have some message bytes in fifo */
1458 		get_msgin(ms);
1459 		n = msgin_length(ms);
1460 		if (ms->n_msgin < n) {
1461 			out_8(&mr->count_lo, n - ms->n_msgin);
1462 			out_8(&mr->sequence, SEQ_MSGIN + seq);
1463 		} else {
1464 			ms->msgphase = msg_none;
1465 			handle_msgin(ms);
1466 			start_phase(ms);
1467 		}
1468 		break;
1469 
1470 	case msg_in_bad:
1471 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1472 		mesh_flush_io(mr);
1473 		udelay(1);
1474 		out_8(&mr->count_lo, 1);
1475 		out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
1476 		break;
1477 
1478 	case msg_out:
1479 		/*
1480 		 * To get the right timing on ATN wrt ACK, we have
1481 		 * to get the MESH to drop ACK, wait until REQ gets
1482 		 * asserted, then drop ATN.  To do this we first
1483 		 * issue a SEQ_MSGOUT with ATN and wait for REQ,
1484 		 * then change the command to a SEQ_MSGOUT w/o ATN.
1485 		 * If we don't see REQ in a reasonable time, we
1486 		 * change the command to SEQ_MSGIN with ATN,
1487 		 * wait for the phase mismatch interrupt, then
1488 		 * issue the SEQ_MSGOUT without ATN.
1489 		 */
1490 		out_8(&mr->count_lo, 1);
1491 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
1492 		t = 30;		/* wait up to 30us */
1493 		while ((in_8(&mr->bus_status0) & BS0_REQ) == 0 && --t >= 0)
1494 			udelay(1);
1495 		dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
1496 		     MKWORD(mr->error, mr->exception,
1497 			    mr->fifo_count, mr->count_lo));
1498 		if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
1499 			/* whoops, target didn't do what we expected */
1500 			ms->last_n_msgout = ms->n_msgout;
1501 			ms->n_msgout = 0;
1502 			if (in_8(&mr->interrupt) & INT_ERROR) {
1503 				printk(KERN_ERR "mesh: error %x in msg_out\n",
1504 				       in_8(&mr->error));
1505 				handle_error(ms);
1506 				return;
1507 			}
1508 			if (in_8(&mr->exception) != EXC_PHASEMM)
1509 				printk(KERN_ERR "mesh: exc %x in msg_out\n",
1510 				       in_8(&mr->exception));
1511 			else
1512 				printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
1513 				       in_8(&mr->bus_status0));
1514 			handle_exception(ms);
1515 			return;
1516 		}
1517 		if (in_8(&mr->bus_status0) & BS0_REQ) {
1518 			out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1519 			mesh_flush_io(mr);
1520 			udelay(1);
1521 			out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1522 			ms->msgphase = msg_out_last;
1523 		} else {
1524 			out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
1525 			ms->msgphase = msg_out_xxx;
1526 		}
1527 		break;
1528 
1529 	case msg_out_last:
1530 		ms->last_n_msgout = ms->n_msgout;
1531 		ms->n_msgout = 0;
1532 		ms->msgphase = ms->expect_reply? msg_in: msg_none;
1533 		start_phase(ms);
1534 		break;
1535 
1536 	case msg_none:
1537 		switch (ms->phase) {
1538 		case idle:
1539 			printk(KERN_ERR "mesh: interrupt in idle phase?\n");
1540 			dumpslog(ms);
1541 			return;
1542 		case selecting:
1543 			dlog(ms, "Selecting phase at command completion",0);
1544 			ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
1545 						 (cmd? cmd->device->lun: 0));
1546 			ms->n_msgout = 1;
1547 			ms->expect_reply = 0;
1548 			if (ms->aborting) {
1549 				ms->msgout[0] = ABORT;
1550 				ms->n_msgout++;
1551 			} else if (tp->sdtr_state == do_sdtr) {
1552 				/* add SDTR message */
1553 				add_sdtr_msg(ms);
1554 				ms->expect_reply = 1;
1555 				tp->sdtr_state = sdtr_sent;
1556 			}
1557 			ms->msgphase = msg_out;
1558 			/*
1559 			 * We need to wait for REQ before dropping ATN.
1560 			 * We wait for at most 30us, then fall back to
1561 			 * a scheme where we issue a SEQ_COMMAND with ATN,
1562 			 * which will give us a phase mismatch interrupt
1563 			 * when REQ does come, and then we send the message.
1564 			 */
1565 			t = 230;		/* wait up to 230us */
1566 			while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
1567 				if (--t < 0) {
1568 					dlog(ms, "impatient for req", ms->n_msgout);
1569 					ms->msgphase = msg_none;
1570 					break;
1571 				}
1572 				udelay(1);
1573 			}
1574 			break;
1575 		case dataing:
1576 			if (ms->dma_count != 0) {
1577 				start_phase(ms);
1578 				return;
1579 			}
1580 			/*
1581 			 * We can get a phase mismatch here if the target
1582 			 * changes to the status phase, even though we have
1583 			 * had a command complete interrupt.  Then, if we
1584 			 * issue the SEQ_STATUS command, we'll get a sequence
1585 			 * error interrupt.  Which isn't so bad except that
1586 			 * occasionally the mesh actually executes the
1587 			 * SEQ_STATUS *as well as* giving us the sequence
1588 			 * error and phase mismatch exception.
1589 			 */
1590 			out_8(&mr->sequence, 0);
1591 			out_8(&mr->interrupt,
1592 			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1593 			halt_dma(ms);
1594 			break;
1595 		case statusing:
1596 			if (cmd) {
1597 				struct mesh_cmd_priv *mcmd = mesh_priv(cmd);
1598 
1599 				mcmd->status = mr->fifo;
1600 				if (DEBUG_TARGET(cmd))
1601 					printk(KERN_DEBUG "mesh: status is %x\n",
1602 					       mcmd->status);
1603 			}
1604 			ms->msgphase = msg_in;
1605 			break;
1606 		case busfreeing:
1607 			mesh_done(ms, 1);
1608 			return;
1609 		case disconnecting:
1610 			ms->current_req = NULL;
1611 			ms->phase = idle;
1612 			mesh_start(ms);
1613 			return;
1614 		default:
1615 			break;
1616 		}
1617 		++ms->phase;
1618 		start_phase(ms);
1619 		break;
1620 	}
1621 }
1622 
1623 
1624 /*
1625  * Called by midlayer with host locked to queue a new
1626  * request
1627  */
1628 static int mesh_queue_lck(struct scsi_cmnd *cmd)
1629 {
1630 	struct mesh_state *ms;
1631 
1632 	cmd->host_scribble = NULL;
1633 
1634 	ms = (struct mesh_state *) cmd->device->host->hostdata;
1635 
1636 	if (ms->request_q == NULL)
1637 		ms->request_q = cmd;
1638 	else
1639 		ms->request_qtail->host_scribble = (void *) cmd;
1640 	ms->request_qtail = cmd;
1641 
1642 	if (ms->phase == idle)
1643 		mesh_start(ms);
1644 
1645 	return 0;
1646 }
1647 
1648 static DEF_SCSI_QCMD(mesh_queue)
1649 
1650 /*
1651  * Called to handle interrupts, either call by the interrupt
1652  * handler (do_mesh_interrupt) or by other functions in
1653  * exceptional circumstances
1654  */
1655 static void mesh_interrupt(struct mesh_state *ms)
1656 {
1657 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1658 	int intr;
1659 
1660 #if 0
1661 	if (ALLOW_DEBUG(ms->conn_tgt))
1662 		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
1663 		       "phase=%d msgphase=%d\n", mr->bus_status0,
1664 		       mr->interrupt, mr->exception, mr->error,
1665 		       ms->phase, ms->msgphase);
1666 #endif
1667 	while ((intr = in_8(&mr->interrupt)) != 0) {
1668 		dlog(ms, "interrupt intr/err/exc/seq=%.8x",
1669 		     MKWORD(intr, mr->error, mr->exception, mr->sequence));
1670 		if (intr & INT_ERROR) {
1671 			handle_error(ms);
1672 		} else if (intr & INT_EXCEPTION) {
1673 			handle_exception(ms);
1674 		} else if (intr & INT_CMDDONE) {
1675 			out_8(&mr->interrupt, INT_CMDDONE);
1676 			cmd_complete(ms);
1677 		}
1678 	}
1679 }
1680 
1681 /* Todo: here we can at least try to remove the command from the
1682  * queue if it isn't connected yet, and for pending command, assert
1683  * ATN until the bus gets freed.
1684  */
1685 static int mesh_abort(struct scsi_cmnd *cmd)
1686 {
1687 	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1688 
1689 	printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
1690 	mesh_dump_regs(ms);
1691 	dumplog(ms, cmd->device->id);
1692 	dumpslog(ms);
1693 	return FAILED;
1694 }
1695 
1696 /*
1697  * Called by the midlayer with the lock held to reset the
1698  * SCSI host and bus.
1699  * The midlayer will wait for devices to come back, we don't need
1700  * to do that ourselves
1701  */
1702 static int mesh_host_reset(struct scsi_cmnd *cmd)
1703 {
1704 	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1705 	volatile struct mesh_regs __iomem *mr = ms->mesh;
1706 	volatile struct dbdma_regs __iomem *md = ms->dma;
1707 	unsigned long flags;
1708 
1709 	printk(KERN_DEBUG "mesh_host_reset\n");
1710 
1711 	spin_lock_irqsave(ms->host->host_lock, flags);
1712 
1713 	if (ms->dma_started)
1714 		halt_dma(ms);
1715 
1716 	/* Reset the controller & dbdma channel */
1717 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
1718 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
1719 	out_8(&mr->error, 0xff);	/* clear all error bits */
1720 	out_8(&mr->sequence, SEQ_RESETMESH);
1721        	mesh_flush_io(mr);
1722 	udelay(1);
1723 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1724 	out_8(&mr->source_id, ms->host->this_id);
1725 	out_8(&mr->sel_timeout, 25);	/* 250ms */
1726 	out_8(&mr->sync_params, ASYNC_PARAMS);
1727 
1728 	/* Reset the bus */
1729 	out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
1730        	mesh_flush_io(mr);
1731 	udelay(30);			/* leave it on for >= 25us */
1732 	out_8(&mr->bus_status1, 0);	/* negate RST */
1733 
1734 	/* Complete pending commands */
1735 	handle_reset(ms);
1736 
1737 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1738 	return SUCCESS;
1739 }
1740 
1741 static void set_mesh_power(struct mesh_state *ms, int state)
1742 {
1743 	if (!machine_is(powermac))
1744 		return;
1745 	if (state) {
1746 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
1747 		msleep(200);
1748 	} else {
1749 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
1750 		msleep(10);
1751 	}
1752 }
1753 
1754 
1755 #ifdef CONFIG_PM
1756 static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
1757 {
1758 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1759 	unsigned long flags;
1760 
1761 	switch (mesg.event) {
1762 	case PM_EVENT_SUSPEND:
1763 	case PM_EVENT_HIBERNATE:
1764 	case PM_EVENT_FREEZE:
1765 		break;
1766 	default:
1767 		return 0;
1768 	}
1769 	if (ms->phase == sleeping)
1770 		return 0;
1771 
1772 	scsi_block_requests(ms->host);
1773 	spin_lock_irqsave(ms->host->host_lock, flags);
1774 	while(ms->phase != idle) {
1775 		spin_unlock_irqrestore(ms->host->host_lock, flags);
1776 		msleep(10);
1777 		spin_lock_irqsave(ms->host->host_lock, flags);
1778 	}
1779 	ms->phase = sleeping;
1780 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1781 	disable_irq(ms->meshintr);
1782 	set_mesh_power(ms, 0);
1783 
1784 	return 0;
1785 }
1786 
1787 static int mesh_resume(struct macio_dev *mdev)
1788 {
1789 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1790 	unsigned long flags;
1791 
1792 	if (ms->phase != sleeping)
1793 		return 0;
1794 
1795 	set_mesh_power(ms, 1);
1796 	mesh_init(ms);
1797 	spin_lock_irqsave(ms->host->host_lock, flags);
1798 	mesh_start(ms);
1799 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1800 	enable_irq(ms->meshintr);
1801 	scsi_unblock_requests(ms->host);
1802 
1803 	return 0;
1804 }
1805 
1806 #endif /* CONFIG_PM */
1807 
1808 /*
1809  * If we leave drives set for synchronous transfers (especially
1810  * CDROMs), and reboot to MacOS, it gets confused, poor thing.
1811  * So, on reboot we reset the SCSI bus.
1812  */
1813 static int mesh_shutdown(struct macio_dev *mdev)
1814 {
1815 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1816 	volatile struct mesh_regs __iomem *mr;
1817 	unsigned long flags;
1818 
1819        	printk(KERN_INFO "resetting MESH scsi bus(es)\n");
1820 	spin_lock_irqsave(ms->host->host_lock, flags);
1821        	mr = ms->mesh;
1822 	out_8(&mr->intr_mask, 0);
1823 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1824 	out_8(&mr->bus_status1, BS1_RST);
1825 	mesh_flush_io(mr);
1826 	udelay(30);
1827 	out_8(&mr->bus_status1, 0);
1828 	spin_unlock_irqrestore(ms->host->host_lock, flags);
1829 
1830 	return 0;
1831 }
1832 
1833 static struct scsi_host_template mesh_template = {
1834 	.proc_name			= "mesh",
1835 	.name				= "MESH",
1836 	.queuecommand			= mesh_queue,
1837 	.eh_abort_handler		= mesh_abort,
1838 	.eh_host_reset_handler		= mesh_host_reset,
1839 	.can_queue			= 20,
1840 	.this_id			= 7,
1841 	.sg_tablesize			= SG_ALL,
1842 	.cmd_per_lun			= 2,
1843 	.max_segment_size		= 65535,
1844 	.cmd_size			= sizeof(struct mesh_cmd_priv),
1845 };
1846 
1847 static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
1848 {
1849 	struct device_node *mesh = macio_get_of_node(mdev);
1850 	struct pci_dev* pdev = macio_get_pci_dev(mdev);
1851 	int tgt, minper;
1852 	const int *cfp;
1853 	struct mesh_state *ms;
1854 	struct Scsi_Host *mesh_host;
1855 	void *dma_cmd_space;
1856 	dma_addr_t dma_cmd_bus;
1857 
1858 	switch (mdev->bus->chip->type) {
1859 	case macio_heathrow:
1860 	case macio_gatwick:
1861 	case macio_paddington:
1862 		use_active_neg = 0;
1863 		break;
1864 	default:
1865 		use_active_neg = SEQ_ACTIVE_NEG;
1866 	}
1867 
1868 	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
1869        		printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
1870 	       	       " (got %d,%d)\n", macio_resource_count(mdev),
1871 		       macio_irq_count(mdev));
1872 		return -ENODEV;
1873 	}
1874 
1875 	if (macio_request_resources(mdev, "mesh") != 0) {
1876        		printk(KERN_ERR "mesh: unable to request memory resources");
1877 		return -EBUSY;
1878 	}
1879        	mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
1880 	if (mesh_host == NULL) {
1881 		printk(KERN_ERR "mesh: couldn't register host");
1882 		goto out_release;
1883 	}
1884 
1885 	mesh_host->base = macio_resource_start(mdev, 0);
1886 	mesh_host->irq = macio_irq(mdev, 0);
1887        	ms = (struct mesh_state *) mesh_host->hostdata;
1888 	macio_set_drvdata(mdev, ms);
1889 	ms->host = mesh_host;
1890 	ms->mdev = mdev;
1891 	ms->pdev = pdev;
1892 
1893 	ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
1894 	if (ms->mesh == NULL) {
1895 		printk(KERN_ERR "mesh: can't map registers\n");
1896 		goto out_free;
1897 	}
1898 	ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
1899 	if (ms->dma == NULL) {
1900 		printk(KERN_ERR "mesh: can't map registers\n");
1901 		iounmap(ms->mesh);
1902 		goto out_free;
1903 	}
1904 
1905        	ms->meshintr = macio_irq(mdev, 0);
1906        	ms->dmaintr = macio_irq(mdev, 1);
1907 
1908        	/* Space for dma command list: +1 for stop command,
1909        	 * +1 to allow for aligning.
1910 	 */
1911 	ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);
1912 
1913 	/* We use the PCI APIs for now until the generic one gets fixed
1914 	 * enough or until we get some macio-specific versions
1915 	 */
1916 	dma_cmd_space = dma_alloc_coherent(&macio_get_pci_dev(mdev)->dev,
1917 					   ms->dma_cmd_size, &dma_cmd_bus,
1918 					   GFP_KERNEL);
1919 	if (dma_cmd_space == NULL) {
1920 		printk(KERN_ERR "mesh: can't allocate DMA table\n");
1921 		goto out_unmap;
1922 	}
1923 
1924 	ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
1925        	ms->dma_cmd_space = dma_cmd_space;
1926 	ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
1927 		- (unsigned long)dma_cmd_space;
1928 	ms->current_req = NULL;
1929        	for (tgt = 0; tgt < 8; ++tgt) {
1930 	       	ms->tgts[tgt].sdtr_state = do_sdtr;
1931 	       	ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1932 	       	ms->tgts[tgt].current_req = NULL;
1933        	}
1934 
1935 	if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
1936        		ms->clk_freq = *cfp;
1937 	else {
1938        		printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
1939 	       	ms->clk_freq = 50000000;
1940        	}
1941 
1942        	/* The maximum sync rate is clock / 5; increase
1943        	 * mesh_sync_period if necessary.
1944 	 */
1945 	minper = 1000000000 / (ms->clk_freq / 5); /* ns */
1946 	if (mesh_sync_period < minper)
1947 		mesh_sync_period = minper;
1948 
1949 	/* Power up the chip */
1950 	set_mesh_power(ms, 1);
1951 
1952 	/* Set it up */
1953        	mesh_init(ms);
1954 
1955 	/* Request interrupt */
1956        	if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
1957 	       	printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
1958 		goto out_shutdown;
1959 	}
1960 
1961 	/* Add scsi host & scan */
1962 	if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
1963 		goto out_release_irq;
1964 	scsi_scan_host(mesh_host);
1965 
1966 	return 0;
1967 
1968  out_release_irq:
1969 	free_irq(ms->meshintr, ms);
1970  out_shutdown:
1971 	/* shutdown & reset bus in case of error or macos can be confused
1972 	 * at reboot if the bus was set to synchronous mode already
1973 	 */
1974 	mesh_shutdown(mdev);
1975 	set_mesh_power(ms, 0);
1976 	dma_free_coherent(&macio_get_pci_dev(mdev)->dev, ms->dma_cmd_size,
1977 			    ms->dma_cmd_space, ms->dma_cmd_bus);
1978  out_unmap:
1979 	iounmap(ms->dma);
1980 	iounmap(ms->mesh);
1981  out_free:
1982 	scsi_host_put(mesh_host);
1983  out_release:
1984 	macio_release_resources(mdev);
1985 
1986 	return -ENODEV;
1987 }
1988 
1989 static int mesh_remove(struct macio_dev *mdev)
1990 {
1991 	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1992 	struct Scsi_Host *mesh_host = ms->host;
1993 
1994 	scsi_remove_host(mesh_host);
1995 
1996 	free_irq(ms->meshintr, ms);
1997 
1998 	/* Reset scsi bus */
1999 	mesh_shutdown(mdev);
2000 
2001 	/* Shut down chip & termination */
2002 	set_mesh_power(ms, 0);
2003 
2004 	/* Unmap registers & dma controller */
2005 	iounmap(ms->mesh);
2006        	iounmap(ms->dma);
2007 
2008 	/* Free DMA commands memory */
2009 	dma_free_coherent(&macio_get_pci_dev(mdev)->dev, ms->dma_cmd_size,
2010 			    ms->dma_cmd_space, ms->dma_cmd_bus);
2011 
2012 	/* Release memory resources */
2013 	macio_release_resources(mdev);
2014 
2015 	scsi_host_put(mesh_host);
2016 
2017 	return 0;
2018 }
2019 
2020 
2021 static struct of_device_id mesh_match[] =
2022 {
2023 	{
2024 	.name 		= "mesh",
2025 	},
2026 	{
2027 	.type		= "scsi",
2028 	.compatible	= "chrp,mesh0"
2029 	},
2030 	{},
2031 };
2032 MODULE_DEVICE_TABLE (of, mesh_match);
2033 
2034 static struct macio_driver mesh_driver =
2035 {
2036 	.driver = {
2037 		.name 		= "mesh",
2038 		.owner		= THIS_MODULE,
2039 		.of_match_table	= mesh_match,
2040 	},
2041 	.probe		= mesh_probe,
2042 	.remove		= mesh_remove,
2043 	.shutdown	= mesh_shutdown,
2044 #ifdef CONFIG_PM
2045 	.suspend	= mesh_suspend,
2046 	.resume		= mesh_resume,
2047 #endif
2048 };
2049 
2050 
2051 static int __init init_mesh(void)
2052 {
2053 
2054 	/* Calculate sync rate from module parameters */
2055 	if (sync_rate > 10)
2056 		sync_rate = 10;
2057 	if (sync_rate > 0) {
2058 		printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
2059 		mesh_sync_period = 1000 / sync_rate;	/* ns */
2060 		mesh_sync_offset = 15;
2061 	} else
2062 		printk(KERN_INFO "mesh: configured for asynchronous\n");
2063 
2064 	return macio_register_driver(&mesh_driver);
2065 }
2066 
2067 static void __exit exit_mesh(void)
2068 {
2069 	return macio_unregister_driver(&mesh_driver);
2070 }
2071 
2072 module_init(init_mesh);
2073 module_exit(exit_mesh);
2074