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/system.h>
  37#include <asm/irq.h>
  38#include <asm/hydra.h>
  39#include <asm/processor.h>
  40#include <asm/machdep.h>
  41#include <asm/pmac_feature.h>
  42#include <asm/pci-bridge.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
  57MODULE_AUTHOR("Paul Mackerras (paulus@samba.org)");
  58MODULE_DESCRIPTION("PowerMac MESH SCSI driver");
  59MODULE_LICENSE("GPL");
  60
  61static int sync_rate = CONFIG_SCSI_MESH_SYNC_RATE;
  62static int sync_targets = 0xff;
  63static int resel_targets = 0xff;
  64static int debug_targets = 0;	/* print debug for these targets */
  65static int init_reset_delay = CONFIG_SCSI_MESH_RESET_DELAY_MS;
  66
  67module_param(sync_rate, int, 0);
  68MODULE_PARM_DESC(sync_rate, "Synchronous rate (0..10, 0=async)");
  69module_param(sync_targets, int, 0);
  70MODULE_PARM_DESC(sync_targets, "Bitmask of targets allowed to set synchronous");
  71module_param(resel_targets, int, 0);
  72MODULE_PARM_DESC(resel_targets, "Bitmask of targets allowed to set disconnect");
  73module_param(debug_targets, int, 0644);
  74MODULE_PARM_DESC(debug_targets, "Bitmask of debugged targets");
  75module_param(init_reset_delay, int, 0);
  76MODULE_PARM_DESC(init_reset_delay, "Initial bus reset delay (0=no reset)");
  77
  78static int mesh_sync_period = 100;
  79static int mesh_sync_offset = 0;
  80static 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
  93struct dbglog {
  94	char	*fmt;
  95	u32	tb;
  96	u8	phase;
  97	u8	bs0;
  98	u8	bs1;
  99	u8	tgt;
 100	int	d;
 101};
 102
 103enum mesh_phase {
 104	idle,
 105	arbitrating,
 106	selecting,
 107	commanding,
 108	dataing,
 109	statusing,
 110	busfreeing,
 111	disconnecting,
 112	reselecting,
 113	sleeping
 114};
 115
 116enum 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
 125enum sdtr_phase {
 126	do_sdtr,
 127	sdtr_sent,
 128	sdtr_done
 129};
 130
 131struct 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
 144struct 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 */
 186static void mesh_done(struct mesh_state *ms, int start_next);
 187static void mesh_interrupt(struct mesh_state *ms);
 188static void cmd_complete(struct mesh_state *ms);
 189static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd);
 190static void halt_dma(struct mesh_state *ms);
 191static void phase_mismatch(struct mesh_state *ms);
 192
 193
 194/*
 195 * Some debugging & logging routines
 196 */
 197
 198#ifdef MESH_DBG
 199
 200static 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
 213static 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
 238static 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
 264static 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
 291static inline void dlog(struct mesh_state *ms, char *fmt, int a)
 292{}
 293static inline void dumplog(struct mesh_state *ms, int tgt)
 294{}
 295static 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
 302static void
 303mesh_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 */
 339static inline void mesh_flush_io(volatile struct mesh_regs __iomem *mr)
 340{
 341	(void)in_8(&mr->mesh_id);
 342}
 343
 344
 345/*
 346 * Complete a SCSI command
 347 */
 348static void mesh_completed(struct mesh_state *ms, struct scsi_cmnd *cmd)
 349{
 350	(*cmd->scsi_done)(cmd);
 351}
 352
 353
 354/* Called with  meshinterrupt disabled, initialize the chipset
 355 * and eventually do the initial bus reset. The lock must not be
 356 * held since we can schedule.
 357 */
 358static void mesh_init(struct mesh_state *ms)
 359{
 360	volatile struct mesh_regs __iomem *mr = ms->mesh;
 361	volatile struct dbdma_regs __iomem *md = ms->dma;
 362
 363	mesh_flush_io(mr);
 364	udelay(100);
 365
 366	/* Reset controller */
 367	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
 368	out_8(&mr->exception, 0xff);	/* clear all exception bits */
 369	out_8(&mr->error, 0xff);	/* clear all error bits */
 370	out_8(&mr->sequence, SEQ_RESETMESH);
 371	mesh_flush_io(mr);
 372	udelay(10);
 373	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 374	out_8(&mr->source_id, ms->host->this_id);
 375	out_8(&mr->sel_timeout, 25);	/* 250ms */
 376	out_8(&mr->sync_params, ASYNC_PARAMS);
 377
 378	if (init_reset_delay) {
 379		printk(KERN_INFO "mesh: performing initial bus reset...\n");
 380		
 381		/* Reset bus */
 382		out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
 383		mesh_flush_io(mr);
 384		udelay(30);			/* leave it on for >= 25us */
 385		out_8(&mr->bus_status1, 0);	/* negate RST */
 386		mesh_flush_io(mr);
 387
 388		/* Wait for bus to come back */
 389		msleep(init_reset_delay);
 390	}
 391	
 392	/* Reconfigure controller */
 393	out_8(&mr->interrupt, 0xff);	/* clear all interrupt bits */
 394	out_8(&mr->sequence, SEQ_FLUSHFIFO);
 395	mesh_flush_io(mr);
 396	udelay(1);
 397	out_8(&mr->sync_params, ASYNC_PARAMS);
 398	out_8(&mr->sequence, SEQ_ENBRESEL);
 399
 400	ms->phase = idle;
 401	ms->msgphase = msg_none;
 402}
 403
 404
 405static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
 406{
 407	volatile struct mesh_regs __iomem *mr = ms->mesh;
 408	int t, id;
 409
 410	id = cmd->device->id;
 411	ms->current_req = cmd;
 412	ms->tgts[id].data_goes_out = cmd->sc_data_direction == DMA_TO_DEVICE;
 413	ms->tgts[id].current_req = cmd;
 414
 415#if 1
 416	if (DEBUG_TARGET(cmd)) {
 417		int i;
 418		printk(KERN_DEBUG "mesh_start: %p tgt=%d cmd=", cmd, id);
 419		for (i = 0; i < cmd->cmd_len; ++i)
 420			printk(" %x", cmd->cmnd[i]);
 421		printk(" use_sg=%d buffer=%p bufflen=%u\n",
 422		       scsi_sg_count(cmd), scsi_sglist(cmd), scsi_bufflen(cmd));
 423	}
 424#endif
 425	if (ms->dma_started)
 426		panic("mesh: double DMA start !\n");
 427
 428	ms->phase = arbitrating;
 429	ms->msgphase = msg_none;
 430	ms->data_ptr = 0;
 431	ms->dma_started = 0;
 432	ms->n_msgout = 0;
 433	ms->last_n_msgout = 0;
 434	ms->expect_reply = 0;
 435	ms->conn_tgt = id;
 436	ms->tgts[id].saved_ptr = 0;
 437	ms->stat = DID_OK;
 438	ms->aborting = 0;
 439#ifdef MESH_DBG
 440	ms->tgts[id].n_log = 0;
 441	dlog(ms, "start cmd=%x", (int) cmd);
 442#endif
 443
 444	/* Off we go */
 445	dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
 446	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 447	out_8(&mr->interrupt, INT_CMDDONE);
 448	out_8(&mr->sequence, SEQ_ENBRESEL);
 449	mesh_flush_io(mr);
 450	udelay(1);
 451
 452	if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
 453		/*
 454		 * Some other device has the bus or is arbitrating for it -
 455		 * probably a target which is about to reselect us.
 456		 */
 457		dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
 458		     MKWORD(mr->interrupt, mr->exception,
 459			    mr->error, mr->fifo_count));
 460		for (t = 100; t > 0; --t) {
 461			if ((in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) == 0)
 462				break;
 463			if (in_8(&mr->interrupt) != 0) {
 464				dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
 465				     MKWORD(mr->interrupt, mr->exception,
 466					    mr->error, mr->fifo_count));
 467				mesh_interrupt(ms);
 468				if (ms->phase != arbitrating)
 469					return;
 470			}
 471			udelay(1);
 472		}
 473		if (in_8(&mr->bus_status1) & (BS1_BSY | BS1_SEL)) {
 474			/* XXX should try again in a little while */
 475			ms->stat = DID_BUS_BUSY;
 476			ms->phase = idle;
 477			mesh_done(ms, 0);
 478			return;
 479		}
 480	}
 481
 482	/*
 483	 * Apparently the mesh has a bug where it will assert both its
 484	 * own bit and the target's bit on the bus during arbitration.
 485	 */
 486	out_8(&mr->dest_id, mr->source_id);
 487
 488	/*
 489	 * There appears to be a race with reselection sometimes,
 490	 * where a target reselects us just as we issue the
 491	 * arbitrate command.  It seems that then the arbitrate
 492	 * command just hangs waiting for the bus to be free
 493	 * without giving us a reselection exception.
 494	 * The only way I have found to get it to respond correctly
 495	 * is this: disable reselection before issuing the arbitrate
 496	 * command, then after issuing it, if it looks like a target
 497	 * is trying to reselect us, reset the mesh and then enable
 498	 * reselection.
 499	 */
 500	out_8(&mr->sequence, SEQ_DISRESEL);
 501	if (in_8(&mr->interrupt) != 0) {
 502		dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
 503		     MKWORD(mr->interrupt, mr->exception,
 504			    mr->error, mr->fifo_count));
 505		mesh_interrupt(ms);
 506		if (ms->phase != arbitrating)
 507			return;
 508		dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
 509		     MKWORD(mr->interrupt, mr->exception,
 510			    mr->error, mr->fifo_count));
 511	}
 512
 513	out_8(&mr->sequence, SEQ_ARBITRATE);
 514
 515	for (t = 230; t > 0; --t) {
 516		if (in_8(&mr->interrupt) != 0)
 517			break;
 518		udelay(1);
 519	}
 520	dlog(ms, "after arb, intr/exc/err/fc=%.8x",
 521	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 522	if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
 523	    && (in_8(&mr->bus_status0) & BS0_IO)) {
 524		/* looks like a reselection - try resetting the mesh */
 525		dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
 526		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 527		out_8(&mr->sequence, SEQ_RESETMESH);
 528		mesh_flush_io(mr);
 529		udelay(10);
 530		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 531		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 532		out_8(&mr->sequence, SEQ_ENBRESEL);
 533		mesh_flush_io(mr);
 534		for (t = 10; t > 0 && in_8(&mr->interrupt) == 0; --t)
 535			udelay(1);
 536		dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
 537		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
 538#ifndef MESH_MULTIPLE_HOSTS
 539		if (in_8(&mr->interrupt) == 0 && (in_8(&mr->bus_status1) & BS1_SEL)
 540		    && (in_8(&mr->bus_status0) & BS0_IO)) {
 541			printk(KERN_ERR "mesh: controller not responding"
 542			       " to reselection!\n");
 543			/*
 544			 * If this is a target reselecting us, and the
 545			 * mesh isn't responding, the higher levels of
 546			 * the scsi code will eventually time out and
 547			 * reset the bus.
 548			 */
 549		}
 550#endif
 551	}
 552}
 553
 554/*
 555 * Start the next command for a MESH.
 556 * Should be called with interrupts disabled.
 557 */
 558static void mesh_start(struct mesh_state *ms)
 559{
 560	struct scsi_cmnd *cmd, *prev, *next;
 561
 562	if (ms->phase != idle || ms->current_req != NULL) {
 563		printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
 564		       ms->phase, ms);
 565		return;
 566	}
 567
 568	while (ms->phase == idle) {
 569		prev = NULL;
 570		for (cmd = ms->request_q; ; cmd = (struct scsi_cmnd *) cmd->host_scribble) {
 571			if (cmd == NULL)
 572				return;
 573			if (ms->tgts[cmd->device->id].current_req == NULL)
 574				break;
 575			prev = cmd;
 576		}
 577		next = (struct scsi_cmnd *) cmd->host_scribble;
 578		if (prev == NULL)
 579			ms->request_q = next;
 580		else
 581			prev->host_scribble = (void *) next;
 582		if (next == NULL)
 583			ms->request_qtail = prev;
 584
 585		mesh_start_cmd(ms, cmd);
 586	}
 587}
 588
 589static void mesh_done(struct mesh_state *ms, int start_next)
 590{
 591	struct scsi_cmnd *cmd;
 592	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 593
 594	cmd = ms->current_req;
 595	ms->current_req = NULL;
 596	tp->current_req = NULL;
 597	if (cmd) {
 598		cmd->result = (ms->stat << 16) + cmd->SCp.Status;
 599		if (ms->stat == DID_OK)
 600			cmd->result += (cmd->SCp.Message << 8);
 601		if (DEBUG_TARGET(cmd)) {
 602			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
 603			       cmd->result, ms->data_ptr, scsi_bufflen(cmd));
 604#if 0
 605			/* needs to use sg? */
 606			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
 607			    && cmd->request_buffer != 0) {
 608				unsigned char *b = cmd->request_buffer;
 609				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
 610				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
 611			}
 612#endif
 613		}
 614		cmd->SCp.this_residual -= ms->data_ptr;
 615		mesh_completed(ms, cmd);
 616	}
 617	if (start_next) {
 618		out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
 619		mesh_flush_io(ms->mesh);
 620		udelay(1);
 621		ms->phase = idle;
 622		mesh_start(ms);
 623	}
 624}
 625
 626static inline void add_sdtr_msg(struct mesh_state *ms)
 627{
 628	int i = ms->n_msgout;
 629
 630	ms->msgout[i] = EXTENDED_MESSAGE;
 631	ms->msgout[i+1] = 3;
 632	ms->msgout[i+2] = EXTENDED_SDTR;
 633	ms->msgout[i+3] = mesh_sync_period/4;
 634	ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
 635	ms->n_msgout = i + 5;
 636}
 637
 638static void set_sdtr(struct mesh_state *ms, int period, int offset)
 639{
 640	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 641	volatile struct mesh_regs __iomem *mr = ms->mesh;
 642	int v, tr;
 643
 644	tp->sdtr_state = sdtr_done;
 645	if (offset == 0) {
 646		/* asynchronous */
 647		if (SYNC_OFF(tp->sync_params))
 648			printk(KERN_INFO "mesh: target %d now asynchronous\n",
 649			       ms->conn_tgt);
 650		tp->sync_params = ASYNC_PARAMS;
 651		out_8(&mr->sync_params, ASYNC_PARAMS);
 652		return;
 653	}
 654	/*
 655	 * We need to compute ceil(clk_freq * period / 500e6) - 2
 656	 * without incurring overflow.
 657	 */
 658	v = (ms->clk_freq / 5000) * period;
 659	if (v <= 250000) {
 660		/* special case: sync_period == 5 * clk_period */
 661		v = 0;
 662		/* units of tr are 100kB/s */
 663		tr = (ms->clk_freq + 250000) / 500000;
 664	} else {
 665		/* sync_period == (v + 2) * 2 * clk_period */
 666		v = (v + 99999) / 100000 - 2;
 667		if (v > 15)
 668			v = 15;	/* oops */
 669		tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
 670	}
 671	if (offset > 15)
 672		offset = 15;	/* can't happen */
 673	tp->sync_params = SYNC_PARAMS(offset, v);
 674	out_8(&mr->sync_params, tp->sync_params);
 675	printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
 676	       ms->conn_tgt, tr/10, tr%10);
 677}
 678
 679static void start_phase(struct mesh_state *ms)
 680{
 681	int i, seq, nb;
 682	volatile struct mesh_regs __iomem *mr = ms->mesh;
 683	volatile struct dbdma_regs __iomem *md = ms->dma;
 684	struct scsi_cmnd *cmd = ms->current_req;
 685	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 686
 687	dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
 688	     MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
 689	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 690	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
 691	switch (ms->msgphase) {
 692	case msg_none:
 693		break;
 694
 695	case msg_in:
 696		out_8(&mr->count_hi, 0);
 697		out_8(&mr->count_lo, 1);
 698		out_8(&mr->sequence, SEQ_MSGIN + seq);
 699		ms->n_msgin = 0;
 700		return;
 701
 702	case msg_out:
 703		/*
 704		 * To make sure ATN drops before we assert ACK for
 705		 * the last byte of the message, we have to do the
 706		 * last byte specially.
 707		 */
 708		if (ms->n_msgout <= 0) {
 709			printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
 710			       ms->n_msgout);
 711			mesh_dump_regs(ms);
 712			ms->msgphase = msg_none;
 713			break;
 714		}
 715		if (ALLOW_DEBUG(ms->conn_tgt)) {
 716			printk(KERN_DEBUG "mesh: sending %d msg bytes:",
 717			       ms->n_msgout);
 718			for (i = 0; i < ms->n_msgout; ++i)
 719				printk(" %x", ms->msgout[i]);
 720			printk("\n");
 721		}
 722		dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
 723						ms->msgout[1], ms->msgout[2]));
 724		out_8(&mr->count_hi, 0);
 725		out_8(&mr->sequence, SEQ_FLUSHFIFO);
 726		mesh_flush_io(mr);
 727		udelay(1);
 728		/*
 729		 * If ATN is not already asserted, we assert it, then
 730		 * issue a SEQ_MSGOUT to get the mesh to drop ACK.
 731		 */
 732		if ((in_8(&mr->bus_status0) & BS0_ATN) == 0) {
 733			dlog(ms, "bus0 was %.2x explicitly asserting ATN", mr->bus_status0);
 734			out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
 735			mesh_flush_io(mr);
 736			udelay(1);
 737			out_8(&mr->count_lo, 1);
 738			out_8(&mr->sequence, SEQ_MSGOUT + seq);
 739			out_8(&mr->bus_status0, 0); /* release explicit ATN */
 740			dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
 741		}
 742		if (ms->n_msgout == 1) {
 743			/*
 744			 * We can't issue the SEQ_MSGOUT without ATN
 745			 * until the target has asserted REQ.  The logic
 746			 * in cmd_complete handles both situations:
 747			 * REQ already asserted or not.
 748			 */
 749			cmd_complete(ms);
 750		} else {
 751			out_8(&mr->count_lo, ms->n_msgout - 1);
 752			out_8(&mr->sequence, SEQ_MSGOUT + seq);
 753			for (i = 0; i < ms->n_msgout - 1; ++i)
 754				out_8(&mr->fifo, ms->msgout[i]);
 755		}
 756		return;
 757
 758	default:
 759		printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
 760		       ms->msgphase);
 761	}
 762
 763	switch (ms->phase) {
 764	case selecting:
 765		out_8(&mr->dest_id, ms->conn_tgt);
 766		out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
 767		break;
 768	case commanding:
 769		out_8(&mr->sync_params, tp->sync_params);
 770		out_8(&mr->count_hi, 0);
 771		if (cmd) {
 772			out_8(&mr->count_lo, cmd->cmd_len);
 773			out_8(&mr->sequence, SEQ_COMMAND + seq);
 774			for (i = 0; i < cmd->cmd_len; ++i)
 775				out_8(&mr->fifo, cmd->cmnd[i]);
 776		} else {
 777			out_8(&mr->count_lo, 6);
 778			out_8(&mr->sequence, SEQ_COMMAND + seq);
 779			for (i = 0; i < 6; ++i)
 780				out_8(&mr->fifo, 0);
 781		}
 782		break;
 783	case dataing:
 784		/* transfer data, if any */
 785		if (!ms->dma_started) {
 786			set_dma_cmds(ms, cmd);
 787			out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
 788			out_le32(&md->control, (RUN << 16) | RUN);
 789			ms->dma_started = 1;
 790		}
 791		nb = ms->dma_count;
 792		if (nb > 0xfff0)
 793			nb = 0xfff0;
 794		ms->dma_count -= nb;
 795		ms->data_ptr += nb;
 796		out_8(&mr->count_lo, nb);
 797		out_8(&mr->count_hi, nb >> 8);
 798		out_8(&mr->sequence, (tp->data_goes_out?
 799				SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
 800		break;
 801	case statusing:
 802		out_8(&mr->count_hi, 0);
 803		out_8(&mr->count_lo, 1);
 804		out_8(&mr->sequence, SEQ_STATUS + seq);
 805		break;
 806	case busfreeing:
 807	case disconnecting:
 808		out_8(&mr->sequence, SEQ_ENBRESEL);
 809		mesh_flush_io(mr);
 810		udelay(1);
 811		dlog(ms, "enbresel intr/exc/err/fc=%.8x",
 812		     MKWORD(mr->interrupt, mr->exception, mr->error,
 813			    mr->fifo_count));
 814		out_8(&mr->sequence, SEQ_BUSFREE);
 815		break;
 816	default:
 817		printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
 818		       ms->phase);
 819		dumpslog(ms);
 820	}
 821
 822}
 823
 824static inline void get_msgin(struct mesh_state *ms)
 825{
 826	volatile struct mesh_regs __iomem *mr = ms->mesh;
 827	int i, n;
 828
 829	n = mr->fifo_count;
 830	if (n != 0) {
 831		i = ms->n_msgin;
 832		ms->n_msgin = i + n;
 833		for (; n > 0; --n)
 834			ms->msgin[i++] = in_8(&mr->fifo);
 835	}
 836}
 837
 838static inline int msgin_length(struct mesh_state *ms)
 839{
 840	int b, n;
 841
 842	n = 1;
 843	if (ms->n_msgin > 0) {
 844		b = ms->msgin[0];
 845		if (b == 1) {
 846			/* extended message */
 847			n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
 848		} else if (0x20 <= b && b <= 0x2f) {
 849			/* 2-byte message */
 850			n = 2;
 851		}
 852	}
 853	return n;
 854}
 855
 856static void reselected(struct mesh_state *ms)
 857{
 858	volatile struct mesh_regs __iomem *mr = ms->mesh;
 859	struct scsi_cmnd *cmd;
 860	struct mesh_target *tp;
 861	int b, t, prev;
 862
 863	switch (ms->phase) {
 864	case idle:
 865		break;
 866	case arbitrating:
 867		if ((cmd = ms->current_req) != NULL) {
 868			/* put the command back on the queue */
 869			cmd->host_scribble = (void *) ms->request_q;
 870			if (ms->request_q == NULL)
 871				ms->request_qtail = cmd;
 872			ms->request_q = cmd;
 873			tp = &ms->tgts[cmd->device->id];
 874			tp->current_req = NULL;
 875		}
 876		break;
 877	case busfreeing:
 878		ms->phase = reselecting;
 879		mesh_done(ms, 0);
 880		break;
 881	case disconnecting:
 882		break;
 883	default:
 884		printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
 885		       ms->msgphase, ms->phase, ms->conn_tgt);
 886		dumplog(ms, ms->conn_tgt);
 887		dumpslog(ms);
 888	}
 889
 890	if (ms->dma_started) {
 891		printk(KERN_ERR "mesh: reselected with DMA started !\n");
 892		halt_dma(ms);
 893	}
 894	ms->current_req = NULL;
 895	ms->phase = dataing;
 896	ms->msgphase = msg_in;
 897	ms->n_msgout = 0;
 898	ms->last_n_msgout = 0;
 899	prev = ms->conn_tgt;
 900
 901	/*
 902	 * We seem to get abortive reselections sometimes.
 903	 */
 904	while ((in_8(&mr->bus_status1) & BS1_BSY) == 0) {
 905		static int mesh_aborted_resels;
 906		mesh_aborted_resels++;
 907		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 908		mesh_flush_io(mr);
 909		udelay(1);
 910		out_8(&mr->sequence, SEQ_ENBRESEL);
 911		mesh_flush_io(mr);
 912		udelay(5);
 913		dlog(ms, "extra resel err/exc/fc = %.6x",
 914		     MKWORD(0, mr->error, mr->exception, mr->fifo_count));
 915	}
 916	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 917       	mesh_flush_io(mr);
 918	udelay(1);
 919	out_8(&mr->sequence, SEQ_ENBRESEL);
 920       	mesh_flush_io(mr);
 921	udelay(1);
 922	out_8(&mr->sync_params, ASYNC_PARAMS);
 923
 924	/*
 925	 * Find out who reselected us.
 926	 */
 927	if (in_8(&mr->fifo_count) == 0) {
 928		printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
 929		ms->conn_tgt = ms->host->this_id;
 930		goto bogus;
 931	}
 932	/* get the last byte in the fifo */
 933	do {
 934		b = in_8(&mr->fifo);
 935		dlog(ms, "reseldata %x", b);
 936	} while (in_8(&mr->fifo_count));
 937	for (t = 0; t < 8; ++t)
 938		if ((b & (1 << t)) != 0 && t != ms->host->this_id)
 939			break;
 940	if (b != (1 << t) + (1 << ms->host->this_id)) {
 941		printk(KERN_ERR "mesh: bad reselection data %x\n", b);
 942		ms->conn_tgt = ms->host->this_id;
 943		goto bogus;
 944	}
 945
 946
 947	/*
 948	 * Set up to continue with that target's transfer.
 949	 */
 950	ms->conn_tgt = t;
 951	tp = &ms->tgts[t];
 952	out_8(&mr->sync_params, tp->sync_params);
 953	if (ALLOW_DEBUG(t)) {
 954		printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
 955		printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
 956		       tp->saved_ptr, tp->data_goes_out, tp->current_req);
 957	}
 958	ms->current_req = tp->current_req;
 959	if (tp->current_req == NULL) {
 960		printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
 961		goto bogus;
 962	}
 963	ms->data_ptr = tp->saved_ptr;
 964	dlog(ms, "resel prev tgt=%d", prev);
 965	dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
 966	start_phase(ms);
 967	return;
 968
 969bogus:
 970	dumplog(ms, ms->conn_tgt);
 971	dumpslog(ms);
 972	ms->data_ptr = 0;
 973	ms->aborting = 1;
 974	start_phase(ms);
 975}
 976
 977static void do_abort(struct mesh_state *ms)
 978{
 979	ms->msgout[0] = ABORT;
 980	ms->n_msgout = 1;
 981	ms->aborting = 1;
 982	ms->stat = DID_ABORT;
 983	dlog(ms, "abort", 0);
 984}
 985
 986static void handle_reset(struct mesh_state *ms)
 987{
 988	int tgt;
 989	struct mesh_target *tp;
 990	struct scsi_cmnd *cmd;
 991	volatile struct mesh_regs __iomem *mr = ms->mesh;
 992
 993	for (tgt = 0; tgt < 8; ++tgt) {
 994		tp = &ms->tgts[tgt];
 995		if ((cmd = tp->current_req) != NULL) {
 996			cmd->result = DID_RESET << 16;
 997			tp->current_req = NULL;
 998			mesh_completed(ms, cmd);
 999		}
1000		ms->tgts[tgt].sdtr_state = do_sdtr;
1001		ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1002	}
1003	ms->current_req = NULL;
1004	while ((cmd = ms->request_q) != NULL) {
1005		ms->request_q = (struct scsi_cmnd *) cmd->host_scribble;
1006		cmd->result = DID_RESET << 16;
1007		mesh_completed(ms, cmd);
1008	}
1009	ms->phase = idle;
1010	ms->msgphase = msg_none;
1011	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1012	out_8(&mr->sequence, SEQ_FLUSHFIFO);
1013       	mesh_flush_io(mr);
1014	udelay(1);
1015	out_8(&mr->sync_params, ASYNC_PARAMS);
1016	out_8(&mr->sequence, SEQ_ENBRESEL);
1017}
1018
1019static irqreturn_t do_mesh_interrupt(int irq, void *dev_id)
1020{
1021	unsigned long flags;
1022	struct mesh_state *ms = dev_id;
1023	struct Scsi_Host *dev = ms->host;
1024	
1025	spin_lock_irqsave(dev->host_lock, flags);
1026	mesh_interrupt(ms);
1027	spin_unlock_irqrestore(dev->host_lock, flags);
1028	return IRQ_HANDLED;
1029}
1030
1031static void handle_error(struct mesh_state *ms)
1032{
1033	int err, exc, count;
1034	volatile struct mesh_regs __iomem *mr = ms->mesh;
1035
1036	err = in_8(&mr->error);
1037	exc = in_8(&mr->exception);
1038	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1039	dlog(ms, "error err/exc/fc/cl=%.8x",
1040	     MKWORD(err, exc, mr->fifo_count, mr->count_lo));
1041	if (err & ERR_SCSIRESET) {
1042		/* SCSI bus was reset */
1043		printk(KERN_INFO "mesh: SCSI bus reset detected: "
1044		       "waiting for end...");
1045		while ((in_8(&mr->bus_status1) & BS1_RST) != 0)
1046			udelay(1);
1047		printk("done\n");
1048		handle_reset(ms);
1049		/* request_q is empty, no point in mesh_start() */
1050		return;
1051	}
1052	if (err & ERR_UNEXPDISC) {
1053		/* Unexpected disconnect */
1054		if (exc & EXC_RESELECTED) {
1055			reselected(ms);
1056			return;
1057		}
1058		if (!ms->aborting) {
1059			printk(KERN_WARNING "mesh: target %d aborted\n",
1060			       ms->conn_tgt);
1061			dumplog(ms, ms->conn_tgt);
1062			dumpslog(ms);
1063		}
1064		out_8(&mr->interrupt, INT_CMDDONE);
1065		ms->stat = DID_ABORT;
1066		mesh_done(ms, 1);
1067		return;
1068	}
1069	if (err & ERR_PARITY) {
1070		if (ms->msgphase == msg_in) {
1071			printk(KERN_ERR "mesh: msg parity error, target %d\n",
1072			       ms->conn_tgt);
1073			ms->msgout[0] = MSG_PARITY_ERROR;
1074			ms->n_msgout = 1;
1075			ms->msgphase = msg_in_bad;
1076			cmd_complete(ms);
1077			return;
1078		}
1079		if (ms->stat == DID_OK) {
1080			printk(KERN_ERR "mesh: parity error, target %d\n",
1081			       ms->conn_tgt);
1082			ms->stat = DID_PARITY;
1083		}
1084		count = (mr->count_hi << 8) + mr->count_lo;
1085		if (count == 0) {
1086			cmd_complete(ms);
1087		} else {
1088			/* reissue the data transfer command */
1089			out_8(&mr->sequence, mr->sequence);
1090		}
1091		return;
1092	}
1093	if (err & ERR_SEQERR) {
1094		if (exc & EXC_RESELECTED) {
1095			/* This can happen if we issue a command to
1096			   get the bus just after the target reselects us. */
1097			static int mesh_resel_seqerr;
1098			mesh_resel_seqerr++;
1099			reselected(ms);
1100			return;
1101		}
1102		if (exc == EXC_PHASEMM) {
1103			static int mesh_phasemm_seqerr;
1104			mesh_phasemm_seqerr++;
1105			phase_mismatch(ms);
1106			return;
1107		}
1108		printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
1109		       err, exc);
1110	} else {
1111		printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
1112	}
1113	mesh_dump_regs(ms);
1114	dumplog(ms, ms->conn_tgt);
1115	if (ms->phase > selecting && (in_8(&mr->bus_status1) & BS1_BSY)) {
1116		/* try to do what the target wants */
1117		do_abort(ms);
1118		phase_mismatch(ms);
1119		return;
1120	}
1121	ms->stat = DID_ERROR;
1122	mesh_done(ms, 1);
1123}
1124
1125static void handle_exception(struct mesh_state *ms)
1126{
1127	int exc;
1128	volatile struct mesh_regs __iomem *mr = ms->mesh;
1129
1130	exc = in_8(&mr->exception);
1131	out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
1132	if (exc & EXC_RESELECTED) {
1133		static int mesh_resel_exc;
1134		mesh_resel_exc++;
1135		reselected(ms);
1136	} else if (exc == EXC_ARBLOST) {
1137		printk(KERN_DEBUG "mesh: lost arbitration\n");
1138		ms->stat = DID_BUS_BUSY;
1139		mesh_done(ms, 1);
1140	} else if (exc == EXC_SELTO) {
1141		/* selection timed out */
1142		ms->stat = DID_BAD_TARGET;
1143		mesh_done(ms, 1);
1144	} else if (exc == EXC_PHASEMM) {
1145		/* target wants to do something different:
1146		   find out what it wants and do it. */
1147		phase_mismatch(ms);
1148	} else {
1149		printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
1150		mesh_dump_regs(ms);
1151		dumplog(ms, ms->conn_tgt);
1152		do_abort(ms);
1153		phase_mismatch(ms);
1154	}
1155}
1156
1157static void handle_msgin(struct mesh_state *ms)
1158{
1159	int i, code;
1160	struct scsi_cmnd *cmd = ms->current_req;
1161	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1162
1163	if (ms->n_msgin == 0)
1164		return;
1165	code = ms->msgin[0];
1166	if (ALLOW_DEBUG(ms->conn_tgt)) {
1167		printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
1168		for (i = 0; i < ms->n_msgin; ++i)
1169			printk(" %x", ms->msgin[i]);
1170		printk("\n");
1171	}
1172	dlog(ms, "msgin msg=%.8x",
1173	     MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
1174
1175	ms->expect_reply = 0;
1176	ms->n_msgout = 0;
1177	if (ms->n_msgin < msgin_length(ms))
1178		goto reject;
1179	if (cmd)
1180		cmd->SCp.Message = code;
1181	switch (code) {
1182	case COMMAND_COMPLETE:
1183		break;
1184	case EXTENDED_MESSAGE:
1185		switch (ms->msgin[2]) {
1186		case EXTENDED_MODIFY_DATA_POINTER:
1187			ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
1188				+ (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
1189			break;
1190		case EXTENDED_SDTR:
1191			if (tp->sdtr_state != sdtr_sent) {
1192				/* reply with an SDTR */
1193				add_sdtr_msg(ms);
1194				/* limit period to at least his value,
1195				   offset to no more than his */
1196				if (ms->msgout[3] < ms->msgin[3])
1197					ms->msgout[3] = ms->msgin[3];
1198				if (ms->msgout[4] > ms->msgin[4])
1199					ms->msgout[4] = ms->msgin[4];
1200				set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
1201				ms->msgphase = msg_out;
1202			} else {
1203				set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
1204			}
1205			break;
1206		default:
1207			goto reject;
1208		}
1209		break;
1210	case SAVE_POINTERS:
1211		tp->saved_ptr = ms->data_ptr;
1212		break;
1213	case RESTORE_POINTERS:
1214		ms->data_ptr = tp->saved_ptr;
1215		break;
1216	case DISCONNECT:
1217		ms->phase = disconnecting;
1218		break;
1219	case ABORT:
1220		break;
1221	case MESSAGE_REJECT:
1222		if (tp->sdtr_state == sdtr_sent)
1223			set_sdtr(ms, 0, 0);
1224		break;
1225	case NOP:
1226		break;
1227	default:
1228		if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
1229			if (cmd == NULL) {
1230				do_abort(ms);
1231				ms->msgphase = msg_out;
1232			} else if (code != cmd->device->lun + IDENTIFY_BASE) {
1233				printk(KERN_WARNING "mesh: lun mismatch "
1234				       "(%d != %d) on reselection from "
1235				       "target %d\n", code - IDENTIFY_BASE,
1236				       cmd->device->lun, ms->conn_tgt);
1237			}
1238			break;
1239		}
1240		goto reject;
1241	}
1242	return;
1243
1244 reject:
1245	printk(KERN_WARNING "mesh: rejecting message from target %d:",
1246	       ms->conn_tgt);
1247	for (i = 0; i < ms->n_msgin; ++i)
1248		printk(" %x", ms->msgin[i]);
1249	printk("\n");
1250	ms->msgout[0] = MESSAGE_REJECT;
1251	ms->n_msgout = 1;
1252	ms->msgphase = msg_out;
1253}
1254
1255/*
1256 * Set up DMA commands for transferring data.
1257 */
1258static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
1259{
1260	int i, dma_cmd, total, off, dtot;
1261	struct scatterlist *scl;
1262	struct dbdma_cmd *dcmds;
1263
1264	dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
1265		OUTPUT_MORE: INPUT_MORE;
1266	dcmds = ms->dma_cmds;
1267	dtot = 0;
1268	if (cmd) {
1269		int nseg;
1270
1271		cmd->SCp.this_residual = scsi_bufflen(cmd);
1272
1273		nseg = scsi_dma_map(cmd);
1274		BUG_ON(nseg < 0);
1275
1276		if (nseg) {
1277			total = 0;
1278			off = ms->data_ptr;
1279
1280			scsi_for_each_sg(cmd, scl, nseg, i) {
1281				u32 dma_addr = sg_dma_address(scl);
1282				u32 dma_len = sg_dma_len(scl);
1283				
1284				total += scl->length;
1285				if (off >= dma_len) {
1286					off -= dma_len;
1287					continue;
1288				}
1289				if (dma_len > 0xffff)
1290					panic("mesh: scatterlist element >= 64k");
1291				st_le16(&dcmds->req_count, dma_len - off);
1292				st_le16(&dcmds->command, dma_cmd);
1293				st_le32(&dcmds->phy_addr, dma_addr + off);
1294				dcmds->xfer_status = 0;
1295				++dcmds;
1296				dtot += dma_len - off;
1297				off = 0;
1298			}
1299		}
1300	}
1301	if (dtot == 0) {
1302		/* Either the target has overrun our buffer,
1303		   or the caller didn't provide a buffer. */
1304		static char mesh_extra_buf[64];
1305
1306		dtot = sizeof(mesh_extra_buf);
1307		st_le16(&dcmds->req_count, dtot);
1308		st_le32(&dcmds->phy_addr, virt_to_phys(mesh_extra_buf));
1309		dcmds->xfer_status = 0;
1310		++dcmds;
1311	}
1312	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
1313	st_le16(&dcmds[-1].command, dma_cmd);
1314	memset(dcmds, 0, sizeof(*dcmds));
1315	st_le16(&dcmds->command, DBDMA_STOP);
1316	ms->dma_count = dtot;
1317}
1318
1319static void halt_dma(struct mesh_state *ms)
1320{
1321	volatile struct dbdma_regs __iomem *md = ms->dma;
1322	volatile struct mesh_regs __iomem *mr = ms->mesh;
1323	struct scsi_cmnd *cmd = ms->current_req;
1324	int t, nb;
1325
1326	if (!ms->tgts[ms->conn_tgt].data_goes_out) {
1327		/* wait a little while until the fifo drains */
1328		t = 50;
1329		while (t > 0 && in_8(&mr->fifo_count) != 0
1330		       && (in_le32(&md->status) & ACTIVE) != 0) {
1331			--t;
1332			udelay(1);
1333		}
1334	}
1335	out_le32(&md->control, RUN << 16);	/* turn off RUN bit */
1336	nb = (mr->count_hi << 8) + mr->count_lo;
1337	dlog(ms, "halt_dma fc/count=%.6x",
1338	     MKWORD(0, mr->fifo_count, 0, nb));
1339	if (ms->tgts[ms->conn_tgt].data_goes_out)
1340		nb += mr->fifo_count;
1341	/* nb is the number of bytes not yet transferred
1342	   to/from the target. */
1343	ms->data_ptr -= nb;
1344	dlog(ms, "data_ptr %x", ms->data_ptr);
1345	if (ms->data_ptr < 0) {
1346		printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
1347		       ms->data_ptr, nb, ms);
1348		ms->data_ptr = 0;
1349#ifdef MESH_DBG
1350		dumplog(ms, ms->conn_tgt);
1351		dumpslog(ms);
1352#endif /* MESH_DBG */
1353	} else if (cmd && scsi_bufflen(cmd) &&
1354		   ms->data_ptr > scsi_bufflen(cmd)) {
1355		printk(KERN_DEBUG "mesh: target %d overrun, "
1356		       "data_ptr=%x total=%x goes_out=%d\n",
1357		       ms->conn_tgt, ms->data_ptr, scsi_bufflen(cmd),
1358		       ms->tgts[ms->conn_tgt].data_goes_out);
1359	}
1360	scsi_dma_unmap(cmd);
1361	ms->dma_started = 0;
1362}
1363
1364static void phase_mismatch(struct mesh_state *ms)
1365{
1366	volatile struct mesh_regs __iomem *mr = ms->mesh;
1367	int phase;
1368
1369	dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
1370	     MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
1371	phase = in_8(&mr->bus_status0) & BS0_PHASE;
1372	if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
1373		/* output the last byte of the message, without ATN */
1374		out_8(&mr->count_lo, 1);
1375		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1376		mesh_flush_io(mr);
1377		udelay(1);
1378		out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1379		ms->msgphase = msg_out_last;
1380		return;
1381	}
1382
1383	if (ms->msgphase == msg_in) {
1384		get_msgin(ms);
1385		if (ms->n_msgin)
1386			handle_msgin(ms);
1387	}
1388
1389	if (ms->dma_started)
1390		halt_dma(ms);
1391	if (mr->fifo_count) {
1392		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1393		mesh_flush_io(mr);
1394		udelay(1);
1395	}
1396
1397	ms->msgphase = msg_none;
1398	switch (phase) {
1399	case BP_DATAIN:
1400		ms->tgts[ms->conn_tgt].data_goes_out = 0;
1401		ms->phase = dataing;
1402		break;
1403	case BP_DATAOUT:
1404		ms->tgts[ms->conn_tgt].data_goes_out = 1;
1405		ms->phase = dataing;
1406		break;
1407	case BP_COMMAND:
1408		ms->phase = commanding;
1409		break;
1410	case BP_STATUS:
1411		ms->phase = statusing;
1412		break;
1413	case BP_MSGIN:
1414		ms->msgphase = msg_in;
1415		ms->n_msgin = 0;
1416		break;
1417	case BP_MSGOUT:
1418		ms->msgphase = msg_out;
1419		if (ms->n_msgout == 0) {
1420			if (ms->aborting) {
1421				do_abort(ms);
1422			} else {
1423				if (ms->last_n_msgout == 0) {
1424					printk(KERN_DEBUG
1425					       "mesh: no msg to repeat\n");
1426					ms->msgout[0] = NOP;
1427					ms->last_n_msgout = 1;
1428				}
1429				ms->n_msgout = ms->last_n_msgout;
1430			}
1431		}
1432		break;
1433	default:
1434		printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
1435		ms->stat = DID_ERROR;
1436		mesh_done(ms, 1);
1437		return;
1438	}
1439
1440	start_phase(ms);
1441}
1442
1443static void cmd_complete(struct mesh_state *ms)
1444{
1445	volatile struct mesh_regs __iomem *mr = ms->mesh;
1446	struct scsi_cmnd *cmd = ms->current_req;
1447	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1448	int seq, n, t;
1449
1450	dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
1451	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
1452	switch (ms->msgphase) {
1453	case msg_out_xxx:
1454		/* huh?  we expected a phase mismatch */
1455		ms->n_msgin = 0;
1456		ms->msgphase = msg_in;
1457		/* fall through */
1458
1459	case msg_in:
1460		/* should have some message bytes in fifo */
1461		get_msgin(ms);
1462		n = msgin_length(ms);
1463		if (ms->n_msgin < n) {
1464			out_8(&mr->count_lo, n - ms->n_msgin);
1465			out_8(&mr->sequence, SEQ_MSGIN + seq);
1466		} else {
1467			ms->msgphase = msg_none;
1468			handle_msgin(ms);
1469			start_phase(ms);
1470		}
1471		break;
1472
1473	case msg_in_bad:
1474		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1475		mesh_flush_io(mr);
1476		udelay(1);
1477		out_8(&mr->count_lo, 1);
1478		out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
1479		break;
1480
1481	case msg_out:
1482		/*
1483		 * To get the right timing on ATN wrt ACK, we have
1484		 * to get the MESH to drop ACK, wait until REQ gets
1485		 * asserted, then drop ATN.  To do this we first
1486		 * issue a SEQ_MSGOUT with ATN and wait for REQ,
1487		 * then change the command to a SEQ_MSGOUT w/o ATN.
1488		 * If we don't see REQ in a reasonable time, we
1489		 * change the command to SEQ_MSGIN with ATN,
1490		 * wait for the phase mismatch interrupt, then
1491		 * issue the SEQ_MSGOUT without ATN.
1492		 */
1493		out_8(&mr->count_lo, 1);
1494		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
1495		t = 30;		/* wait up to 30us */
1496		while ((in_8(&mr->bus_status0) & BS0_REQ) == 0 && --t >= 0)
1497			udelay(1);
1498		dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
1499		     MKWORD(mr->error, mr->exception,
1500			    mr->fifo_count, mr->count_lo));
1501		if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
1502			/* whoops, target didn't do what we expected */
1503			ms->last_n_msgout = ms->n_msgout;
1504			ms->n_msgout = 0;
1505			if (in_8(&mr->interrupt) & INT_ERROR) {
1506				printk(KERN_ERR "mesh: error %x in msg_out\n",
1507				       in_8(&mr->error));
1508				handle_error(ms);
1509				return;
1510			}
1511			if (in_8(&mr->exception) != EXC_PHASEMM)
1512				printk(KERN_ERR "mesh: exc %x in msg_out\n",
1513				       in_8(&mr->exception));
1514			else
1515				printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
1516				       in_8(&mr->bus_status0));
1517			handle_exception(ms);
1518			return;
1519		}
1520		if (in_8(&mr->bus_status0) & BS0_REQ) {
1521			out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1522			mesh_flush_io(mr);
1523			udelay(1);
1524			out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1525			ms->msgphase = msg_out_last;
1526		} else {
1527			out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
1528			ms->msgphase = msg_out_xxx;
1529		}
1530		break;
1531
1532	case msg_out_last:
1533		ms->last_n_msgout = ms->n_msgout;
1534		ms->n_msgout = 0;
1535		ms->msgphase = ms->expect_reply? msg_in: msg_none;
1536		start_phase(ms);
1537		break;
1538
1539	case msg_none:
1540		switch (ms->phase) {
1541		case idle:
1542			printk(KERN_ERR "mesh: interrupt in idle phase?\n");
1543			dumpslog(ms);
1544			return;
1545		case selecting:
1546			dlog(ms, "Selecting phase at command completion",0);
1547			ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
1548						 (cmd? cmd->device->lun: 0));
1549			ms->n_msgout = 1;
1550			ms->expect_reply = 0;
1551			if (ms->aborting) {
1552				ms->msgout[0] = ABORT;
1553				ms->n_msgout++;
1554			} else if (tp->sdtr_state == do_sdtr) {
1555				/* add SDTR message */
1556				add_sdtr_msg(ms);
1557				ms->expect_reply = 1;
1558				tp->sdtr_state = sdtr_sent;
1559			}
1560			ms->msgphase = msg_out;
1561			/*
1562			 * We need to wait for REQ before dropping ATN.
1563			 * We wait for at most 30us, then fall back to
1564			 * a scheme where we issue a SEQ_COMMAND with ATN,
1565			 * which will give us a phase mismatch interrupt
1566			 * when REQ does come, and then we send the message.
1567			 */
1568			t = 230;		/* wait up to 230us */
1569			while ((in_8(&mr->bus_status0) & BS0_REQ) == 0) {
1570				if (--t < 0) {
1571					dlog(ms, "impatient for req", ms->n_msgout);
1572					ms->msgphase = msg_none;
1573					break;
1574				}
1575				udelay(1);
1576			}
1577			break;
1578		case dataing:
1579			if (ms->dma_count != 0) {
1580				start_phase(ms);
1581				return;
1582			}
1583			/*
1584			 * We can get a phase mismatch here if the target
1585			 * changes to the status phase, even though we have
1586			 * had a command complete interrupt.  Then, if we
1587			 * issue the SEQ_STATUS command, we'll get a sequence
1588			 * error interrupt.  Which isn't so bad except that
1589			 * occasionally the mesh actually executes the
1590			 * SEQ_STATUS *as well as* giving us the sequence
1591			 * error and phase mismatch exception.
1592			 */
1593			out_8(&mr->sequence, 0);
1594			out_8(&mr->interrupt,
1595			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1596			halt_dma(ms);
1597			break;
1598		case statusing:
1599			if (cmd) {
1600				cmd->SCp.Status = mr->fifo;
1601				if (DEBUG_TARGET(cmd))
1602					printk(KERN_DEBUG "mesh: status is %x\n",
1603					       cmd->SCp.Status);
1604			}
1605			ms->msgphase = msg_in;
1606			break;
1607		case busfreeing:
1608			mesh_done(ms, 1);
1609			return;
1610		case disconnecting:
1611			ms->current_req = NULL;
1612			ms->phase = idle;
1613			mesh_start(ms);
1614			return;
1615		default:
1616			break;
1617		}
1618		++ms->phase;
1619		start_phase(ms);
1620		break;
1621	}
1622}
1623
1624
1625/*
1626 * Called by midlayer with host locked to queue a new
1627 * request
1628 */
1629static int mesh_queue_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
1630{
1631	struct mesh_state *ms;
1632
1633	cmd->scsi_done = done;
1634	cmd->host_scribble = NULL;
1635
1636	ms = (struct mesh_state *) cmd->device->host->hostdata;
1637
1638	if (ms->request_q == NULL)
1639		ms->request_q = cmd;
1640	else
1641		ms->request_qtail->host_scribble = (void *) cmd;
1642	ms->request_qtail = cmd;
1643
1644	if (ms->phase == idle)
1645		mesh_start(ms);
1646
1647	return 0;
1648}
1649
1650static DEF_SCSI_QCMD(mesh_queue)
1651
1652/*
1653 * Called to handle interrupts, either call by the interrupt
1654 * handler (do_mesh_interrupt) or by other functions in
1655 * exceptional circumstances
1656 */
1657static void mesh_interrupt(struct mesh_state *ms)
1658{
1659	volatile struct mesh_regs __iomem *mr = ms->mesh;
1660	int intr;
1661
1662#if 0
1663	if (ALLOW_DEBUG(ms->conn_tgt))
1664		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
1665		       "phase=%d msgphase=%d\n", mr->bus_status0,
1666		       mr->interrupt, mr->exception, mr->error,
1667		       ms->phase, ms->msgphase);
1668#endif
1669	while ((intr = in_8(&mr->interrupt)) != 0) {
1670		dlog(ms, "interrupt intr/err/exc/seq=%.8x", 
1671		     MKWORD(intr, mr->error, mr->exception, mr->sequence));
1672		if (intr & INT_ERROR) {
1673			handle_error(ms);
1674		} else if (intr & INT_EXCEPTION) {
1675			handle_exception(ms);
1676		} else if (intr & INT_CMDDONE) {
1677			out_8(&mr->interrupt, INT_CMDDONE);
1678			cmd_complete(ms);
1679		}
1680	}
1681}
1682
1683/* Todo: here we can at least try to remove the command from the
1684 * queue if it isn't connected yet, and for pending command, assert
1685 * ATN until the bus gets freed.
1686 */
1687static int mesh_abort(struct scsi_cmnd *cmd)
1688{
1689	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1690
1691	printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
1692	mesh_dump_regs(ms);
1693	dumplog(ms, cmd->device->id);
1694	dumpslog(ms);
1695	return FAILED;
1696}
1697
1698/*
1699 * Called by the midlayer with the lock held to reset the
1700 * SCSI host and bus.
1701 * The midlayer will wait for devices to come back, we don't need
1702 * to do that ourselves
1703 */
1704static int mesh_host_reset(struct scsi_cmnd *cmd)
1705{
1706	struct mesh_state *ms = (struct mesh_state *) cmd->device->host->hostdata;
1707	volatile struct mesh_regs __iomem *mr = ms->mesh;
1708	volatile struct dbdma_regs __iomem *md = ms->dma;
1709	unsigned long flags;
1710
1711	printk(KERN_DEBUG "mesh_host_reset\n");
1712
1713	spin_lock_irqsave(ms->host->host_lock, flags);
1714
1715	/* Reset the controller & dbdma channel */
1716	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
1717	out_8(&mr->exception, 0xff);	/* clear all exception bits */
1718	out_8(&mr->error, 0xff);	/* clear all error bits */
1719	out_8(&mr->sequence, SEQ_RESETMESH);
1720       	mesh_flush_io(mr);
1721	udelay(1);
1722	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1723	out_8(&mr->source_id, ms->host->this_id);
1724	out_8(&mr->sel_timeout, 25);	/* 250ms */
1725	out_8(&mr->sync_params, ASYNC_PARAMS);
1726
1727	/* Reset the bus */
1728	out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
1729       	mesh_flush_io(mr);
1730	udelay(30);			/* leave it on for >= 25us */
1731	out_8(&mr->bus_status1, 0);	/* negate RST */
1732
1733	/* Complete pending commands */
1734	handle_reset(ms);
1735	
1736	spin_unlock_irqrestore(ms->host->host_lock, flags);
1737	return SUCCESS;
1738}
1739
1740static void set_mesh_power(struct mesh_state *ms, int state)
1741{
1742	if (!machine_is(powermac))
1743		return;
1744	if (state) {
1745		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 1);
1746		msleep(200);
1747	} else {
1748		pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
1749		msleep(10);
1750	}
1751}
1752
1753
1754#ifdef CONFIG_PM
1755static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
1756{
1757	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1758	unsigned long flags;
1759
1760	switch (mesg.event) {
1761	case PM_EVENT_SUSPEND:
1762	case PM_EVENT_HIBERNATE:
1763	case PM_EVENT_FREEZE:
1764		break;
1765	default:
1766		return 0;
1767	}
1768	if (ms->phase == sleeping)
1769		return 0;
1770
1771	scsi_block_requests(ms->host);
1772	spin_lock_irqsave(ms->host->host_lock, flags);
1773	while(ms->phase != idle) {
1774		spin_unlock_irqrestore(ms->host->host_lock, flags);
1775		msleep(10);
1776		spin_lock_irqsave(ms->host->host_lock, flags);
1777	}
1778	ms->phase = sleeping;
1779	spin_unlock_irqrestore(ms->host->host_lock, flags);
1780	disable_irq(ms->meshintr);
1781	set_mesh_power(ms, 0);
1782
1783	return 0;
1784}
1785
1786static int mesh_resume(struct macio_dev *mdev)
1787{
1788	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1789	unsigned long flags;
1790
1791	if (ms->phase != sleeping)
1792		return 0;
1793
1794	set_mesh_power(ms, 1);
1795	mesh_init(ms);
1796	spin_lock_irqsave(ms->host->host_lock, flags);
1797	mesh_start(ms);
1798	spin_unlock_irqrestore(ms->host->host_lock, flags);
1799	enable_irq(ms->meshintr);
1800	scsi_unblock_requests(ms->host);
1801
1802	return 0;
1803}
1804
1805#endif /* CONFIG_PM */
1806
1807/*
1808 * If we leave drives set for synchronous transfers (especially
1809 * CDROMs), and reboot to MacOS, it gets confused, poor thing.
1810 * So, on reboot we reset the SCSI bus.
1811 */
1812static int mesh_shutdown(struct macio_dev *mdev)
1813{
1814	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1815	volatile struct mesh_regs __iomem *mr;
1816	unsigned long flags;
1817
1818       	printk(KERN_INFO "resetting MESH scsi bus(es)\n");
1819	spin_lock_irqsave(ms->host->host_lock, flags);
1820       	mr = ms->mesh;
1821	out_8(&mr->intr_mask, 0);
1822	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1823	out_8(&mr->bus_status1, BS1_RST);
1824	mesh_flush_io(mr);
1825	udelay(30);
1826	out_8(&mr->bus_status1, 0);
1827	spin_unlock_irqrestore(ms->host->host_lock, flags);
1828
1829	return 0;
1830}
1831
1832static struct scsi_host_template mesh_template = {
1833	.proc_name			= "mesh",
1834	.name				= "MESH",
1835	.queuecommand			= mesh_queue,
1836	.eh_abort_handler		= mesh_abort,
1837	.eh_host_reset_handler		= mesh_host_reset,
1838	.can_queue			= 20,
1839	.this_id			= 7,
1840	.sg_tablesize			= SG_ALL,
1841	.cmd_per_lun			= 2,
1842	.use_clustering			= DISABLE_CLUSTERING,
1843};
1844
1845static int mesh_probe(struct macio_dev *mdev, const struct of_device_id *match)
1846{
1847	struct device_node *mesh = macio_get_of_node(mdev);
1848	struct pci_dev* pdev = macio_get_pci_dev(mdev);
1849	int tgt, minper;
1850	const int *cfp;
1851	struct mesh_state *ms;
1852	struct Scsi_Host *mesh_host;
1853	void *dma_cmd_space;
1854	dma_addr_t dma_cmd_bus;
1855
1856	switch (mdev->bus->chip->type) {
1857	case macio_heathrow:
1858	case macio_gatwick:
1859	case macio_paddington:
1860		use_active_neg = 0;
1861		break;
1862	default:
1863		use_active_neg = SEQ_ACTIVE_NEG;
1864	}
1865
1866	if (macio_resource_count(mdev) != 2 || macio_irq_count(mdev) != 2) {
1867       		printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
1868	       	       " (got %d,%d)\n", macio_resource_count(mdev),
1869		       macio_irq_count(mdev));
1870		return -ENODEV;
1871	}
1872
1873	if (macio_request_resources(mdev, "mesh") != 0) {
1874       		printk(KERN_ERR "mesh: unable to request memory resources");
1875		return -EBUSY;
1876	}
1877       	mesh_host = scsi_host_alloc(&mesh_template, sizeof(struct mesh_state));
1878	if (mesh_host == NULL) {
1879		printk(KERN_ERR "mesh: couldn't register host");
1880		goto out_release;
1881	}
1882	
1883	/* Old junk for root discovery, that will die ultimately */
1884#if !defined(MODULE)
1885       	note_scsi_host(mesh, mesh_host);
1886#endif
1887
1888	mesh_host->base = macio_resource_start(mdev, 0);
1889	mesh_host->irq = macio_irq(mdev, 0);
1890       	ms = (struct mesh_state *) mesh_host->hostdata;
1891	macio_set_drvdata(mdev, ms);
1892	ms->host = mesh_host;
1893	ms->mdev = mdev;
1894	ms->pdev = pdev;
1895	
1896	ms->mesh = ioremap(macio_resource_start(mdev, 0), 0x1000);
1897	if (ms->mesh == NULL) {
1898		printk(KERN_ERR "mesh: can't map registers\n");
1899		goto out_free;
1900	}		
1901	ms->dma = ioremap(macio_resource_start(mdev, 1), 0x1000);
1902	if (ms->dma == NULL) {
1903		printk(KERN_ERR "mesh: can't map registers\n");
1904		iounmap(ms->mesh);
1905		goto out_free;
1906	}
1907
1908       	ms->meshintr = macio_irq(mdev, 0);
1909       	ms->dmaintr = macio_irq(mdev, 1);
1910
1911       	/* Space for dma command list: +1 for stop command,
1912       	 * +1 to allow for aligning.
1913	 */
1914	ms->dma_cmd_size = (mesh_host->sg_tablesize + 2) * sizeof(struct dbdma_cmd);
1915
1916	/* We use the PCI APIs for now until the generic one gets fixed
1917	 * enough or until we get some macio-specific versions
1918	 */
1919	dma_cmd_space = pci_alloc_consistent(macio_get_pci_dev(mdev),
1920					     ms->dma_cmd_size,
1921					     &dma_cmd_bus);
1922	if (dma_cmd_space == NULL) {
1923		printk(KERN_ERR "mesh: can't allocate DMA table\n");
1924		goto out_unmap;
1925	}
1926	memset(dma_cmd_space, 0, ms->dma_cmd_size);
1927
1928	ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
1929       	ms->dma_cmd_space = dma_cmd_space;
1930	ms->dma_cmd_bus = dma_cmd_bus + ((unsigned long)ms->dma_cmds)
1931		- (unsigned long)dma_cmd_space;
1932	ms->current_req = NULL;
1933       	for (tgt = 0; tgt < 8; ++tgt) {
1934	       	ms->tgts[tgt].sdtr_state = do_sdtr;
1935	       	ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1936	       	ms->tgts[tgt].current_req = NULL;
1937       	}
1938
1939	if ((cfp = of_get_property(mesh, "clock-frequency", NULL)))
1940       		ms->clk_freq = *cfp;
1941	else {
1942       		printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
1943	       	ms->clk_freq = 50000000;
1944       	}
1945
1946       	/* The maximum sync rate is clock / 5; increase
1947       	 * mesh_sync_period if necessary.
1948	 */
1949	minper = 1000000000 / (ms->clk_freq / 5); /* ns */
1950	if (mesh_sync_period < minper)
1951		mesh_sync_period = minper;
1952
1953	/* Power up the chip */
1954	set_mesh_power(ms, 1);
1955
1956	/* Set it up */
1957       	mesh_init(ms);
1958
1959	/* Request interrupt */
1960       	if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
1961	       	printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
1962		goto out_shutdown;
1963	}
1964
1965	/* Add scsi host & scan */
1966	if (scsi_add_host(mesh_host, &mdev->ofdev.dev))
1967		goto out_release_irq;
1968	scsi_scan_host(mesh_host);
1969
1970	return 0;
1971
1972 out_release_irq:
1973	free_irq(ms->meshintr, ms);
1974 out_shutdown:
1975	/* shutdown & reset bus in case of error or macos can be confused
1976	 * at reboot if the bus was set to synchronous mode already
1977	 */
1978	mesh_shutdown(mdev);
1979	set_mesh_power(ms, 0);
1980	pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
1981			    ms->dma_cmd_space, ms->dma_cmd_bus);
1982 out_unmap:
1983	iounmap(ms->dma);
1984	iounmap(ms->mesh);
1985 out_free:
1986	scsi_host_put(mesh_host);
1987 out_release:
1988	macio_release_resources(mdev);
1989
1990	return -ENODEV;
1991}
1992
1993static int mesh_remove(struct macio_dev *mdev)
1994{
1995	struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
1996	struct Scsi_Host *mesh_host = ms->host;
1997
1998	scsi_remove_host(mesh_host);
1999
2000	free_irq(ms->meshintr, ms);
2001
2002	/* Reset scsi bus */
2003	mesh_shutdown(mdev);
2004
2005	/* Shut down chip & termination */
2006	set_mesh_power(ms, 0);
2007
2008	/* Unmap registers & dma controller */
2009	iounmap(ms->mesh);
2010       	iounmap(ms->dma);
2011
2012	/* Free DMA commands memory */
2013	pci_free_consistent(macio_get_pci_dev(mdev), ms->dma_cmd_size,
2014			    ms->dma_cmd_space, ms->dma_cmd_bus);
2015
2016	/* Release memory resources */
2017	macio_release_resources(mdev);
2018
2019	scsi_host_put(mesh_host);
2020
2021	return 0;
2022}
2023
2024
2025static struct of_device_id mesh_match[] = 
2026{
2027	{
2028	.name 		= "mesh",
2029	},
2030	{
2031	.type		= "scsi",
2032	.compatible	= "chrp,mesh0"
2033	},
2034	{},
2035};
2036MODULE_DEVICE_TABLE (of, mesh_match);
2037
2038static struct macio_driver mesh_driver = 
2039{
2040	.driver = {
2041		.name 		= "mesh",
2042		.owner		= THIS_MODULE,
2043		.of_match_table	= mesh_match,
2044	},
2045	.probe		= mesh_probe,
2046	.remove		= mesh_remove,
2047	.shutdown	= mesh_shutdown,
2048#ifdef CONFIG_PM
2049	.suspend	= mesh_suspend,
2050	.resume		= mesh_resume,
2051#endif
2052};
2053
2054
2055static int __init init_mesh(void)
2056{
2057
2058	/* Calculate sync rate from module parameters */
2059	if (sync_rate > 10)
2060		sync_rate = 10;
2061	if (sync_rate > 0) {
2062		printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
2063		mesh_sync_period = 1000 / sync_rate;	/* ns */
2064		mesh_sync_offset = 15;
2065	} else
2066		printk(KERN_INFO "mesh: configured for asynchronous\n");
2067
2068	return macio_register_driver(&mesh_driver);
2069}
2070
2071static void __exit exit_mesh(void)
2072{
2073	return macio_unregister_driver(&mesh_driver);
2074}
2075
2076module_init(init_mesh);
2077module_exit(exit_mesh);