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