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. 14 2002  - BenH		Rework bus reset code for new error handler
11  *                              Add delay after initial bus reset
12  *                              Add module parameters
13  * To do:
14  * - handle aborts correctly
15  * - retry arbitration if lost (unless higher levels do this for us)
16  */
17 #include <linux/config.h>
18 #include <linux/module.h>
19 #include <linux/kernel.h>
20 #include <linux/delay.h>
21 #include <linux/types.h>
22 #include <linux/string.h>
23 #include <linux/slab.h>
24 #include <linux/blk.h>
25 #include <linux/proc_fs.h>
26 #include <linux/stat.h>
27 #include <linux/tqueue.h>
28 #include <linux/interrupt.h>
29 #include <linux/reboot.h>
30 #include <linux/spinlock.h>
31 #include <linux/pci.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 #ifdef CONFIG_PMAC_PBOOK
44 #include <linux/adb.h>
45 #include <linux/pmu.h>
46 #endif
47 
48 #include "scsi.h"
49 #include "hosts.h"
50 #include "mesh.h"
51 
52 #if 1
53 #undef KERN_DEBUG
54 #define KERN_DEBUG KERN_WARNING
55 #endif
56 
57 MODULE_AUTHOR("Paul Mackerras (paulus@samba.org)");
58 MODULE_DESCRIPTION("PowerMac MESH SCSI driver");
59 MODULE_LICENSE("GPL");
60 
61 MODULE_PARM(sync_rate, "i");
62 MODULE_PARM_DESC(sync_rate, "Synchronous rate (0..10, 0=async)");
63 MODULE_PARM(sync_targets, "i");
64 MODULE_PARM_DESC(sync_targets, "Bitmask of targets allowed to set synchronous");
65 MODULE_PARM(resel_targets, "i");
66 MODULE_PARM_DESC(resel_targets, "Bitmask of targets allowed to set disconnect");
67 MODULE_PARM(debug_targets, "i");
68 MODULE_PARM_DESC(debug_targets, "Bitmask of debugged targets");
69 MODULE_PARM(init_reset_delay, "i");
70 MODULE_PARM_DESC(init_reset_delay, "Initial bus reset delay (0=no reset)");
71 
72 static int sync_rate = CONFIG_SCSI_MESH_SYNC_RATE;
73 static int sync_targets = 0xff;
74 static int resel_targets = 0xff;
75 static int debug_targets = 0;	/* print debug for these targets */
76 static int init_reset_delay = CONFIG_SCSI_MESH_RESET_DELAY_MS;
77 
78 static int mesh_sync_period = 100;
79 static int mesh_sync_offset = 0;
80 static unsigned char use_active_neg = 0;  /* bit mask for SEQ_ACTIVE_NEG if used */
81 
82 #define ALLOW_SYNC(tgt)		((sync_targets >> (tgt)) & 1)
83 #define ALLOW_RESEL(tgt)	((resel_targets >> (tgt)) & 1)
84 #define ALLOW_DEBUG(tgt)	((debug_targets >> (tgt)) & 1)
85 #define DEBUG_TARGET(cmd)	((cmd) && ALLOW_DEBUG((cmd)->target))
86 
87 #undef MESH_DBG
88 #define N_DBG_LOG	50
89 #define N_DBG_SLOG	20
90 #define NUM_DBG_EVENTS	13
91 #undef	DBG_USE_TB		/* bombs on 601 */
92 
93 struct dbglog {
94 	char	*fmt;
95 	u32	tb;
96 	u8	phase;
97 	u8	bs0;
98 	u8	bs1;
99 	u8	tgt;
100 	int	d;
101 };
102 
103 enum mesh_phase {
104 	idle,
105 	arbitrating,
106 	selecting,
107 	commanding,
108 	dataing,
109 	statusing,
110 	busfreeing,
111 	disconnecting,
112 	reselecting,
113 	sleeping
114 };
115 
116 enum msg_phase {
117 	msg_none,
118 	msg_out,
119 	msg_out_xxx,
120 	msg_out_last,
121 	msg_in,
122 	msg_in_bad,
123 };
124 
125 enum sdtr_phase {
126 	do_sdtr,
127 	sdtr_sent,
128 	sdtr_done
129 };
130 
131 struct mesh_target {
132 	enum sdtr_phase sdtr_state;
133 	int	sync_params;
134 	int	data_goes_out;		/* guess as to data direction */
135 	Scsi_Cmnd *current_req;
136 	u32	saved_ptr;
137 #ifdef MESH_DBG
138 	int	log_ix;
139 	int	n_log;
140 	struct dbglog log[N_DBG_LOG];
141 #endif
142 };
143 
144 struct mesh_state {
145 	volatile struct	mesh_regs *mesh;
146 	int	meshintr;
147 	volatile struct	dbdma_regs *dma;
148 	int	dmaintr;
149 	struct	Scsi_Host *host;
150 	struct	mesh_state *next;
151 	Scsi_Cmnd *request_q;
152 	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 	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 	int	clk_freq;
170 	struct mesh_target tgts[8];
171 	void	*dma_cmd_space;
172 	struct device_node *ofnode;
173 	struct pci_dev* pdev;
174 #ifdef MESH_DBG
175 	int	log_ix;
176 	int	n_log;
177 	struct dbglog log[N_DBG_SLOG];
178 #endif
179 };
180 
181 #ifdef MESH_DBG
182 
183 static void dlog(struct mesh_state *ms, char *fmt, int a);
184 static void dumplog(struct mesh_state *ms, int tgt);
185 static void dumpslog(struct mesh_state *ms);
186 
187 #else
dlog(struct mesh_state * ms,char * fmt,int a)188 static inline void dlog(struct mesh_state *ms, char *fmt, int a)
189 {}
dumplog(struct mesh_state * ms,int tgt)190 static inline void dumplog(struct mesh_state *ms, int tgt)
191 {}
dumpslog(struct mesh_state * ms)192 static inline void dumpslog(struct mesh_state *ms)
193 {}
194 
195 #endif /* MESH_DBG */
196 #define MKWORD(a, b, c, d)	(((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
197 
198 static struct mesh_state *all_meshes;
199 
200 static void mesh_init(struct mesh_state *);
201 static int mesh_notify_reboot(struct notifier_block *, unsigned long, void *);
202 static void mesh_dump_regs(struct mesh_state *);
203 static void mesh_start(struct mesh_state *);
204 static void mesh_start_cmd(struct mesh_state *, Scsi_Cmnd *);
205 static void add_sdtr_msg(struct mesh_state *);
206 static void set_sdtr(struct mesh_state *, int, int);
207 static void start_phase(struct mesh_state *);
208 static void get_msgin(struct mesh_state *);
209 static int msgin_length(struct mesh_state *);
210 static void cmd_complete(struct mesh_state *);
211 static void phase_mismatch(struct mesh_state *);
212 static void reselected(struct mesh_state *);
213 static void handle_reset(struct mesh_state *);
214 static void handle_error(struct mesh_state *);
215 static void handle_exception(struct mesh_state *);
216 static void mesh_interrupt(int, void *, struct pt_regs *);
217 static void do_mesh_interrupt(int, void *, struct pt_regs *);
218 static void handle_msgin(struct mesh_state *);
219 static void mesh_done(struct mesh_state *, int);
220 static void mesh_completed(struct mesh_state *, Scsi_Cmnd *);
221 static void set_dma_cmds(struct mesh_state *, Scsi_Cmnd *);
222 static void halt_dma(struct mesh_state *);
223 static int data_goes_out(Scsi_Cmnd *);
224 static void do_abort(struct mesh_state *ms);
225 static void set_mesh_power(struct mesh_state *ms, int state);
226 
227 #ifdef CONFIG_PMAC_PBOOK
228 static int mesh_notify_sleep(struct pmu_sleep_notifier *self, int when);
229 static struct pmu_sleep_notifier mesh_sleep_notifier = {
230 	mesh_notify_sleep,
231 	SLEEP_LEVEL_BLOCK,
232 };
233 #endif
234 
235 static struct notifier_block mesh_notifier = {
236 	mesh_notify_reboot,
237 	NULL,
238 	0
239 };
240 
241 int
mesh_detect(Scsi_Host_Template * tp)242 mesh_detect(Scsi_Host_Template *tp)
243 {
244 	struct device_node *mesh;
245 	int nmeshes, tgt, *cfp, minper;
246 	struct mesh_state *ms, **prev_statep;
247 	struct Scsi_Host *mesh_host;
248 	void *dma_cmd_space;
249 
250 	/* The SCSI layer is dumb ! It calls us with the IO request
251 	 * lock held and interrupts disabled here... This doesn't happen
252 	 * in 2.5
253 	 */
254 	spin_unlock_irq(&io_request_lock);
255 
256 	if (_machine == _MACH_Pmac) {
257 	    use_active_neg = (find_devices("mac-io") ? 0 : SEQ_ACTIVE_NEG);
258 	} else {
259 	    /* CHRP mac-io */
260 	    use_active_neg = SEQ_ACTIVE_NEG;
261 	}
262 
263 	/* Calculate sync rate from module parameters */
264 	if (sync_rate > 10)
265 		sync_rate = 10;
266 	if (sync_rate > 0) {
267 		printk(KERN_INFO "mesh: configured for synchronous %d MB/s\n", sync_rate);
268 		mesh_sync_period = 1000 / sync_rate;	/* ns */
269 		mesh_sync_offset = 15;
270 	} else
271 		printk(KERN_INFO "mesh: configured for asynchronous\n");
272 
273 	nmeshes = 0;
274 	prev_statep = &all_meshes;
275 	/*
276 	 * On powermacs, the MESH node has device_type "mesh".
277 	 * On chrp machines, its device_type is "scsi" with
278 	 * "chrp,mesh0" as its `compatible' property.
279 	 */
280 	mesh = find_devices("mesh");
281 	if (mesh == 0)
282 		mesh = find_compatible_devices("scsi", "chrp,mesh0");
283 	for (; mesh != 0; mesh = mesh->next) {
284 		u8 pci_bus, pci_devfn;
285 		struct pci_dev* pdev = NULL;
286 
287 		if (mesh->n_addrs != 2 || mesh->n_intrs != 2) {
288 			printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
289 			       " (got %d,%d)\n", mesh->n_addrs, mesh->n_intrs);
290 			continue;
291 		}
292 		if (mesh->parent != NULL
293 		    && pci_device_from_OF_node(mesh->parent, &pci_bus,
294 					       &pci_devfn) == 0)
295 			pdev = pci_find_slot(pci_bus, pci_devfn);
296 		if (pdev == NULL) {
297 			printk(KERN_ERR "mesh: Can't locate PCI entry\n");
298 			continue;
299 		}
300 
301 		mesh_host = scsi_register(tp, sizeof(struct mesh_state));
302 		if (mesh_host == 0) {
303 			printk(KERN_ERR "mesh: couldn't register host");
304 			continue;
305 		}
306 		mesh_host->unique_id = nmeshes;
307 #if !defined(MODULE)
308 		note_scsi_host(mesh, mesh_host);
309 #endif
310 
311 		ms = (struct mesh_state *) mesh_host->hostdata;
312 		if (ms == 0)
313 			panic("no mesh state");
314 		memset(ms, 0, sizeof(*ms));
315 		ms->host = mesh_host;
316 		ms->ofnode = mesh;
317 		ms->pdev = pdev;
318 		ms->mesh = (volatile struct mesh_regs *)
319 			ioremap(mesh->addrs[0].address, 0x1000);
320 		ms->dma = (volatile struct dbdma_regs *)
321 			ioremap(mesh->addrs[1].address, 0x1000);
322 		ms->meshintr = mesh->intrs[0].line;
323 		ms->dmaintr = mesh->intrs[1].line;
324 
325 		/* Space for dma command list: +1 for stop command,
326 		   +1 to allow for aligning. */
327 		dma_cmd_space = kmalloc((mesh_host->sg_tablesize + 2) *
328 					sizeof(struct dbdma_cmd), GFP_KERNEL);
329 		if (dma_cmd_space == 0)
330 			panic("mesh: couldn't allocate dma command space");
331 		ms->dma_cmds = (struct dbdma_cmd *) DBDMA_ALIGN(dma_cmd_space);
332 		memset(ms->dma_cmds, 0, (mesh_host->sg_tablesize + 1)
333 		       * sizeof(struct dbdma_cmd));
334 		ms->dma_cmd_space = dma_cmd_space;
335 
336 		ms->current_req = 0;
337 		for (tgt = 0; tgt < 8; ++tgt) {
338 			ms->tgts[tgt].sdtr_state = do_sdtr;
339 			ms->tgts[tgt].sync_params = ASYNC_PARAMS;
340 			ms->tgts[tgt].current_req = 0;
341 		}
342 		*prev_statep = ms;
343 		prev_statep = &ms->next;
344 
345 		if ((cfp = (int *) get_property(mesh, "clock-frequency",
346 						NULL))) {
347 			ms->clk_freq = *cfp;
348 		} else {
349 			printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
350 			ms->clk_freq = 50000000;
351 		}
352 		/* The maximum sync rate is clock / 5; increase
353 		   mesh_sync_period if necessary. */
354 		minper = 1000000000 / (ms->clk_freq / 5);	/* ns */
355 		if (mesh_sync_period < minper)
356 			mesh_sync_period = minper;
357 
358 		set_mesh_power(ms, 1);
359 
360 		mesh_init(ms);
361 
362 		if (request_irq(ms->meshintr, do_mesh_interrupt, 0, "MESH", ms)) {
363 			printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
364 		}
365 
366 		++nmeshes;
367 	}
368 
369 	if ((_machine == _MACH_Pmac) && (nmeshes > 0)) {
370 #ifdef CONFIG_PMAC_PBOOK
371 		pmu_register_sleep_notifier(&mesh_sleep_notifier);
372 #endif /* CONFIG_PMAC_PBOOK */
373 		register_reboot_notifier(&mesh_notifier);
374 	}
375 
376 	/* Return to the SCSI layer in the same state we got called */
377 	spin_lock_irq(&io_request_lock);
378 
379 	return nmeshes;
380 }
381 
382 int
mesh_release(struct Scsi_Host * host)383 mesh_release(struct Scsi_Host *host)
384 {
385 	struct mesh_state *ms = (struct mesh_state *) host->hostdata;
386 
387 	if (ms == 0)
388 		return 0;
389 	if (ms->mesh)
390 		iounmap((void *) ms->mesh);
391 	if (ms->dma)
392 		iounmap((void *) ms->dma);
393 	kfree(ms->dma_cmd_space);
394 	free_irq(ms->meshintr, ms);
395 	pmac_call_feature(PMAC_FTR_MESH_ENABLE, ms->ofnode, 0, 0);
396 	return 0;
397 }
398 
399 static void
set_mesh_power(struct mesh_state * ms,int state)400 set_mesh_power(struct mesh_state *ms, int state)
401 {
402 	if (_machine != _MACH_Pmac)
403 		return;
404 	if (state) {
405 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, ms->ofnode, 0, 1);
406 		mdelay(200);
407 	} else {
408 		pmac_call_feature(PMAC_FTR_MESH_ENABLE, ms->ofnode, 0, 0);
409 		mdelay(10);
410 	}
411 }
412 
413 #ifdef CONFIG_PMAC_PBOOK
414 /*
415  * notify clients before sleep and reset bus afterwards
416  */
417 int
mesh_notify_sleep(struct pmu_sleep_notifier * self,int when)418 mesh_notify_sleep(struct pmu_sleep_notifier *self, int when)
419 {
420 	struct mesh_state *ms;
421 
422 	switch (when) {
423 	case PBOOK_SLEEP_REQUEST:
424 		/* XXX We should wait for current transactions and queue
425 		 * new ones that would be posted beyond this point
426 		 */
427 		break;
428 	case PBOOK_SLEEP_REJECT:
429 		break;
430 
431 	case PBOOK_SLEEP_NOW:
432 		for (ms = all_meshes; ms != 0; ms = ms->next) {
433 			unsigned long flags;
434 
435 			scsi_block_requests(ms->host);
436 			spin_lock_irqsave(&io_request_lock, flags);
437 			while(ms->phase != idle) {
438 				spin_unlock_irqrestore(&io_request_lock, flags);
439 				current->state = TASK_UNINTERRUPTIBLE;
440 				schedule_timeout(1);
441 				spin_lock_irqsave(&io_request_lock, flags);
442 			}
443 			ms->phase = sleeping;
444 			spin_unlock_irqrestore(&io_request_lock, flags);
445 			disable_irq(ms->meshintr);
446 			set_mesh_power(ms, 0);
447 		}
448 		break;
449 	case PBOOK_WAKE:
450 		for (ms = all_meshes; ms != 0; ms = ms->next) {
451 			unsigned long flags;
452 
453 			set_mesh_power(ms, 1);
454 			mesh_init(ms);
455 			spin_lock_irqsave(&io_request_lock, flags);
456 			mesh_start(ms);
457 			spin_unlock_irqrestore(&io_request_lock, flags);
458 			enable_irq(ms->meshintr);
459 			scsi_unblock_requests(ms->host);
460 		}
461 		break;
462 	}
463 	return PBOOK_SLEEP_OK;
464 }
465 #endif /* CONFIG_PMAC_PBOOK */
466 
467 /*
468  * Called by midlayer with host locked to queue a new
469  * request
470  */
471 int
mesh_queue(Scsi_Cmnd * cmd,void (* done)(Scsi_Cmnd *))472 mesh_queue(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
473 {
474 	struct mesh_state *ms;
475 
476 	cmd->scsi_done = done;
477 	cmd->host_scribble = NULL;
478 
479 	ms = (struct mesh_state *) cmd->host->hostdata;
480 
481 	if (ms->request_q == NULL)
482 		ms->request_q = cmd;
483 	else
484 		ms->request_qtail->host_scribble = (void *) cmd;
485 	ms->request_qtail = cmd;
486 
487 	if (ms->phase == idle)
488 		mesh_start(ms);
489 
490 	return 0;
491 }
492 
493 /* Todo: here we can at least try to remove the command from the
494  * queue if it isn't connected yet, and for pending command, assert
495  * ATN until the bus gets freed.
496  */
497 int
mesh_abort(Scsi_Cmnd * cmd)498 mesh_abort(Scsi_Cmnd *cmd)
499 {
500 	struct mesh_state *ms = (struct mesh_state *) cmd->host->hostdata;
501 
502 	printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
503 	mesh_dump_regs(ms);
504 	dumplog(ms, cmd->target);
505 	dumpslog(ms);
506 	return SCSI_ABORT_SNOOZE;
507 }
508 
509 static void
mesh_dump_regs(struct mesh_state * ms)510 mesh_dump_regs(struct mesh_state *ms)
511 {
512 	volatile struct mesh_regs *mr = ms->mesh;
513 	volatile struct dbdma_regs *md = ms->dma;
514 	int t;
515 	struct mesh_target *tp;
516 
517 	printk(KERN_DEBUG "mesh: state at %p, regs at %p, dma at %p\n",
518 	       ms, mr, md);
519 	printk(KERN_DEBUG "    ct=%4x seq=%2x bs=%4x fc=%2x "
520 	       "exc=%2x err=%2x im=%2x int=%2x sp=%2x\n",
521 	       (mr->count_hi << 8) + mr->count_lo, mr->sequence,
522 	       (mr->bus_status1 << 8) + mr->bus_status0, mr->fifo_count,
523 	       mr->exception, mr->error, mr->intr_mask, mr->interrupt,
524 	       mr->sync_params);
525 	while(in_8(&mr->fifo_count))
526 		printk(KERN_DEBUG " fifo data=%.2x\n",in_8(&mr->fifo));
527 	printk(KERN_DEBUG "    dma stat=%x cmdptr=%x\n",
528 	       in_le32(&md->status), in_le32(&md->cmdptr));
529 	printk(KERN_DEBUG "    phase=%d msgphase=%d conn_tgt=%d data_ptr=%d\n",
530 	       ms->phase, ms->msgphase, ms->conn_tgt, ms->data_ptr);
531 	printk(KERN_DEBUG "    dma_st=%d dma_ct=%d n_msgout=%d\n",
532 	       ms->dma_started, ms->dma_count, ms->n_msgout);
533 	for (t = 0; t < 8; ++t) {
534 		tp = &ms->tgts[t];
535 		if (tp->current_req == NULL)
536 			continue;
537 		printk(KERN_DEBUG "    target %d: req=%p goes_out=%d saved_ptr=%d\n",
538 		       t, tp->current_req, tp->data_goes_out, tp->saved_ptr);
539 	}
540 }
541 
542 /*
543  * Called by the midlayer with the lock held to reset the
544  * SCSI host and bus.
545  * The midlayer will wait for devices to come back, we don't need
546  * to do that ourselves
547  */
548 int
mesh_host_reset(Scsi_Cmnd * cmd)549 mesh_host_reset(Scsi_Cmnd *cmd)
550 {
551 	struct mesh_state *ms = (struct mesh_state *) cmd->host->hostdata;
552 	volatile struct mesh_regs *mr = ms->mesh;
553 	volatile struct dbdma_regs *md = ms->dma;
554 
555 	printk(KERN_DEBUG "mesh_host_reset\n");
556 
557 	/* Reset the controller & dbdma channel */
558 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
559 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
560 	out_8(&mr->error, 0xff);	/* clear all error bits */
561 	out_8(&mr->sequence, SEQ_RESETMESH);
562 	udelay(1);
563 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
564 	out_8(&mr->source_id, ms->host->this_id);
565 	out_8(&mr->sel_timeout, 25);	/* 250ms */
566 	out_8(&mr->sync_params, ASYNC_PARAMS);
567 
568 	/* Reset the bus */
569 	out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
570 	udelay(30);			/* leave it on for >= 25us */
571 	out_8(&mr->bus_status1, 0);	/* negate RST */
572 
573 	/* Complete pending commands */
574 	handle_reset(ms);
575 
576 	return SUCCESS;
577 }
578 
579 /*
580  * If we leave drives set for synchronous transfers (especially
581  * CDROMs), and reboot to MacOS, it gets confused, poor thing.
582  * So, on reboot we reset the SCSI bus.
583  */
584 static int
mesh_notify_reboot(struct notifier_block * this,unsigned long code,void * x)585 mesh_notify_reboot(struct notifier_block *this, unsigned long code, void *x)
586 {
587 	struct mesh_state *ms;
588 	volatile struct mesh_regs *mr;
589 
590 	if (code == SYS_DOWN) {
591 		printk(KERN_INFO "resetting MESH scsi bus(es)\n");
592 		for (ms = all_meshes; ms != 0; ms = ms->next) {
593 			mr = ms->mesh;
594 			out_8(&mr->intr_mask, 0);
595 			out_8(&mr->interrupt,
596 			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
597 			out_8(&mr->bus_status1, BS1_RST);
598 			udelay(30);
599 			out_8(&mr->bus_status1, 0);
600 		}
601 	}
602 	return NOTIFY_DONE;
603 }
604 
605 /* Called with  meshinterrupt disabled, initialize the chipset
606  * and eventually do the initial bus reset. The lock must not be
607  * held since we can schedule.
608  */
609 static void
mesh_init(struct mesh_state * ms)610 mesh_init(struct mesh_state *ms)
611 {
612 	volatile struct mesh_regs *mr = ms->mesh;
613 	volatile struct dbdma_regs *md = ms->dma;
614 
615 	udelay(100);
616 
617 	/* Reset controller */
618 	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
619 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
620 	out_8(&mr->error, 0xff);	/* clear all error bits */
621 	out_8(&mr->sequence, SEQ_RESETMESH);
622 	udelay(10);
623 	out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
624 	out_8(&mr->source_id, ms->host->this_id);
625 	out_8(&mr->sel_timeout, 25);	/* 250ms */
626 	out_8(&mr->sync_params, ASYNC_PARAMS);
627 
628 	if (init_reset_delay) {
629 		printk(KERN_INFO "mesh: performing initial bus reset...\n");
630 
631 		/* Reset bus */
632 		out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
633 		udelay(30);			/* leave it on for >= 25us */
634 		out_8(&mr->bus_status1, 0);	/* negate RST */
635 
636 		/* Wait for bus to come back */
637 		current->state = TASK_UNINTERRUPTIBLE;
638 		schedule_timeout((init_reset_delay * HZ) / 1000);
639 	}
640 
641 	/* Reconfigure controller */
642 	out_8(&mr->interrupt, 0xff);	/* clear all interrupt bits */
643 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
644 	udelay(1);
645 	out_8(&mr->sync_params, ASYNC_PARAMS);
646 	out_8(&mr->sequence, SEQ_ENBRESEL);
647 
648 	ms->phase = idle;
649 	ms->msgphase = msg_none;
650 }
651 
652 /*
653  * Start the next command for a MESH.
654  * Should be called with interrupts disabled.
655  */
656 static void
mesh_start(struct mesh_state * ms)657 mesh_start(struct mesh_state *ms)
658 {
659 	Scsi_Cmnd *cmd, *prev, *next;
660 
661 	if (ms->phase != idle || ms->current_req != NULL) {
662 		printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
663 		       ms->phase, ms);
664 		return;
665 	}
666 
667 	while (ms->phase == idle) {
668 		prev = NULL;
669 		for (cmd = ms->request_q; ; cmd = (Scsi_Cmnd *) cmd->host_scribble) {
670 			if (cmd == NULL)
671 				return;
672 			if (ms->tgts[cmd->target].current_req == NULL)
673 				break;
674 			prev = cmd;
675 		}
676 		next = (Scsi_Cmnd *) cmd->host_scribble;
677 		if (prev == NULL)
678 			ms->request_q = next;
679 		else
680 			prev->host_scribble = (void *) next;
681 		if (next == NULL)
682 			ms->request_qtail = prev;
683 
684 		mesh_start_cmd(ms, cmd);
685 	}
686 }
687 
688 static void
mesh_start_cmd(struct mesh_state * ms,Scsi_Cmnd * cmd)689 mesh_start_cmd(struct mesh_state *ms, Scsi_Cmnd *cmd)
690 {
691 	volatile struct mesh_regs *mr = ms->mesh;
692 	int t;
693 
694 	ms->current_req = cmd;
695 	ms->tgts[cmd->target].data_goes_out = data_goes_out(cmd);
696 	ms->tgts[cmd->target].current_req = cmd;
697 
698 #if 1
699 	if (DEBUG_TARGET(cmd)) {
700 		int i;
701 		printk(KERN_DEBUG "mesh_start: %p ser=%lu tgt=%d cmd=",
702 		       cmd, cmd->serial_number, cmd->target);
703 		for (i = 0; i < cmd->cmd_len; ++i)
704 			printk(" %x", cmd->cmnd[i]);
705 		printk(" use_sg=%d buffer=%p bufflen=%u\n",
706 		       cmd->use_sg, cmd->request_buffer, cmd->request_bufflen);
707 	}
708 #endif
709 	if (ms->dma_started)
710 		panic("mesh: double DMA start !\n");
711 
712 	ms->phase = arbitrating;
713 	ms->msgphase = msg_none;
714 	ms->data_ptr = 0;
715 	ms->dma_started = 0;
716 	ms->n_msgout = 0;
717 	ms->last_n_msgout = 0;
718 	ms->expect_reply = 0;
719 	ms->conn_tgt = cmd->target;
720 	ms->tgts[cmd->target].saved_ptr = 0;
721 	ms->stat = DID_OK;
722 	ms->aborting = 0;
723 #ifdef MESH_DBG
724 	ms->tgts[cmd->target].n_log = 0;
725 	dlog(ms, "start cmd=%x", (int) cmd);
726 #endif
727 
728 	/* Off we go */
729 	dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
730 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
731 	out_8(&mr->interrupt, INT_CMDDONE);
732 	out_8(&mr->sequence, SEQ_ENBRESEL);
733 	udelay(1);
734 
735 	if (mr->bus_status1 & (BS1_BSY | BS1_SEL)) {
736 		/*
737 		 * Some other device has the bus or is arbitrating for it -
738 		 * probably a target which is about to reselect us.
739 		 */
740 		dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
741 		     MKWORD(mr->interrupt, mr->exception,
742 			    mr->error, mr->fifo_count));
743 		for (t = 100; t > 0; --t) {
744 			if ((mr->bus_status1 & (BS1_BSY | BS1_SEL)) == 0)
745 				break;
746 			if (in_8(&mr->interrupt) != 0) {
747 				dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
748 				     MKWORD(mr->interrupt, mr->exception,
749 					    mr->error, mr->fifo_count));
750 				mesh_interrupt(0, (void *)ms, 0);
751 				if (ms->phase != arbitrating)
752 					return;
753 			}
754 			udelay(1);
755 		}
756 		if (mr->bus_status1 & (BS1_BSY | BS1_SEL)) {
757 			/* XXX should try again in a little while */
758 			ms->stat = DID_BUS_BUSY;
759 			ms->phase = idle;
760 			mesh_done(ms, 0);
761 			return;
762 		}
763 	}
764 
765 	/*
766 	 * Apparently the mesh has a bug where it will assert both its
767 	 * own bit and the target's bit on the bus during arbitration.
768 	 */
769 	out_8(&mr->dest_id, mr->source_id);
770 
771 	/*
772 	 * There appears to be a race with reselection sometimes,
773 	 * where a target reselects us just as we issue the
774 	 * arbitrate command.  It seems that then the arbitrate
775 	 * command just hangs waiting for the bus to be free
776 	 * without giving us a reselection exception.
777 	 * The only way I have found to get it to respond correctly
778 	 * is this: disable reselection before issuing the arbitrate
779 	 * command, then after issuing it, if it looks like a target
780 	 * is trying to reselect us, reset the mesh and then enable
781 	 * reselection.
782 	 */
783 	out_8(&mr->sequence, SEQ_DISRESEL);
784 	if (in_8(&mr->interrupt) != 0) {
785 		dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
786 		     MKWORD(mr->interrupt, mr->exception,
787 			    mr->error, mr->fifo_count));
788 		mesh_interrupt(0, (void *)ms, 0);
789 		if (ms->phase != arbitrating)
790 			return;
791 		dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
792 		     MKWORD(mr->interrupt, mr->exception,
793 			    mr->error, mr->fifo_count));
794 	}
795 
796 	out_8(&mr->sequence, SEQ_ARBITRATE);
797 
798 	for (t = 230; t > 0; --t) {
799 		if (in_8(&mr->interrupt) != 0)
800 			break;
801 		udelay(1);
802 	}
803 	dlog(ms, "after arb, intr/exc/err/fc=%.8x",
804 	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
805 	if (mr->interrupt == 0 && (mr->bus_status1 & BS1_SEL)
806 	    && (mr->bus_status0 & BS0_IO)) {
807 		/* looks like a reselection - try resetting the mesh */
808 		dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
809 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
810 		out_8(&mr->sequence, SEQ_RESETMESH);
811 		udelay(10);
812 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
813 		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
814 		out_8(&mr->sequence, SEQ_ENBRESEL);
815 		for (t = 10; t > 0 && mr->interrupt == 0; --t)
816 			udelay(1);
817 		dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
818 		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
819 #ifndef MESH_MULTIPLE_HOSTS
820 		if (mr->interrupt == 0 && (mr->bus_status1 & BS1_SEL)
821 		    && (mr->bus_status0 & BS0_IO)) {
822 			printk(KERN_ERR "mesh: controller not responding"
823 			       " to reselection!\n");
824 			/*
825 			 * If this is a target reselecting us, and the
826 			 * mesh isn't responding, the higher levels of
827 			 * the scsi code will eventually time out and
828 			 * reset the bus.
829 			 */
830 		}
831 #endif
832 	}
833 }
834 
835 static inline void
add_sdtr_msg(struct mesh_state * ms)836 add_sdtr_msg(struct mesh_state *ms)
837 {
838 	int i = ms->n_msgout;
839 
840 	ms->msgout[i] = EXTENDED_MESSAGE;
841 	ms->msgout[i+1] = 3;
842 	ms->msgout[i+2] = EXTENDED_SDTR;
843 	ms->msgout[i+3] = mesh_sync_period/4;
844 	ms->msgout[i+4] = (ALLOW_SYNC(ms->conn_tgt)? mesh_sync_offset: 0);
845 	ms->n_msgout = i + 5;
846 }
847 
848 static void
set_sdtr(struct mesh_state * ms,int period,int offset)849 set_sdtr(struct mesh_state *ms, int period, int offset)
850 {
851 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
852 	volatile struct mesh_regs *mr = ms->mesh;
853 	int v, tr;
854 
855 	tp->sdtr_state = sdtr_done;
856 	if (offset == 0) {
857 		/* asynchronous */
858 		if (SYNC_OFF(tp->sync_params))
859 			printk(KERN_INFO "mesh: target %d now asynchronous\n",
860 			       ms->conn_tgt);
861 		tp->sync_params = ASYNC_PARAMS;
862 		out_8(&mr->sync_params, ASYNC_PARAMS);
863 		return;
864 	}
865 	/*
866 	 * We need to compute ceil(clk_freq * period / 500e6) - 2
867 	 * without incurring overflow.
868 	 */
869 	v = (ms->clk_freq / 5000) * period;
870 	if (v <= 250000) {
871 		/* special case: sync_period == 5 * clk_period */
872 		v = 0;
873 		/* units of tr are 100kB/s */
874 		tr = (ms->clk_freq + 250000) / 500000;
875 	} else {
876 		/* sync_period == (v + 2) * 2 * clk_period */
877 		v = (v + 99999) / 100000 - 2;
878 		if (v > 15)
879 			v = 15;	/* oops */
880 		tr = ((ms->clk_freq / (v + 2)) + 199999) / 200000;
881 	}
882 	if (offset > 15)
883 		offset = 15;	/* can't happen */
884 	tp->sync_params = SYNC_PARAMS(offset, v);
885 	out_8(&mr->sync_params, tp->sync_params);
886 	printk(KERN_INFO "mesh: target %d synchronous at %d.%d MB/s\n",
887 	       ms->conn_tgt, tr/10, tr%10);
888 }
889 
890 static void
start_phase(struct mesh_state * ms)891 start_phase(struct mesh_state *ms)
892 {
893 	int i, seq, nb;
894 	volatile struct mesh_regs *mr = ms->mesh;
895 	volatile struct dbdma_regs *md = ms->dma;
896 	Scsi_Cmnd *cmd = ms->current_req;
897 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
898 
899 	dlog(ms, "start_phase nmo/exc/fc/seq = %.8x",
900 	     MKWORD(ms->n_msgout, mr->exception, mr->fifo_count, mr->sequence));
901 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
902 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
903 	switch (ms->msgphase) {
904 	case msg_none:
905 		break;
906 
907 	case msg_in:
908 		out_8(&mr->count_hi, 0);
909 		out_8(&mr->count_lo, 1);
910 		out_8(&mr->sequence, SEQ_MSGIN + seq);
911 		ms->n_msgin = 0;
912 		return;
913 
914 	case msg_out:
915 		/*
916 		 * To make sure ATN drops before we assert ACK for
917 		 * the last byte of the message, we have to do the
918 		 * last byte specially.
919 		 */
920 		if (ms->n_msgout <= 0) {
921 			printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
922 			       ms->n_msgout);
923 			mesh_dump_regs(ms);
924 			ms->msgphase = msg_none;
925 			break;
926 		}
927 		if (ALLOW_DEBUG(ms->conn_tgt)) {
928 			printk(KERN_DEBUG "mesh: sending %d msg bytes:",
929 			       ms->n_msgout);
930 			for (i = 0; i < ms->n_msgout; ++i)
931 				printk(" %x", ms->msgout[i]);
932 			printk("\n");
933 		}
934 		dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
935 						ms->msgout[1], ms->msgout[2]));
936 		out_8(&mr->count_hi, 0);
937 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
938 		udelay(1);
939 		/*
940 		 * If ATN is not already asserted, we assert it, then
941 		 * issue a SEQ_MSGOUT to get the mesh to drop ACK.
942 		 */
943 		if ((mr->bus_status0 & BS0_ATN) == 0) {
944 			dlog(ms, "bus0 was %.2x explictly asserting ATN", mr->bus_status0);
945 			out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
946 			udelay(1);
947 			out_8(&mr->count_lo, 1);
948 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
949 			out_8(&mr->bus_status0, 0); /* release explicit ATN */
950 			dlog(ms,"hace: after explicit ATN bus0=%.2x",mr->bus_status0);
951 		}
952 		if (ms->n_msgout == 1) {
953 			/*
954 			 * We can't issue the SEQ_MSGOUT without ATN
955 			 * until the target has asserted REQ.  The logic
956 			 * in cmd_complete handles both situations:
957 			 * REQ already asserted or not.
958 			 */
959 			cmd_complete(ms);
960 		} else {
961 			out_8(&mr->count_lo, ms->n_msgout - 1);
962 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
963 			for (i = 0; i < ms->n_msgout - 1; ++i)
964 				out_8(&mr->fifo, ms->msgout[i]);
965 		}
966 		return;
967 
968 	default:
969 		printk(KERN_ERR "mesh bug: start_phase msgphase=%d\n",
970 		       ms->msgphase);
971 	}
972 
973 	switch (ms->phase) {
974 	case selecting:
975 		out_8(&mr->dest_id, ms->conn_tgt);
976 		out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
977 		break;
978 	case commanding:
979 		out_8(&mr->sync_params, tp->sync_params);
980 		out_8(&mr->count_hi, 0);
981 		if (cmd) {
982 			out_8(&mr->count_lo, cmd->cmd_len);
983 			out_8(&mr->sequence, SEQ_COMMAND + seq);
984 			for (i = 0; i < cmd->cmd_len; ++i)
985 				out_8(&mr->fifo, cmd->cmnd[i]);
986 		} else {
987 			out_8(&mr->count_lo, 6);
988 			out_8(&mr->sequence, SEQ_COMMAND + seq);
989 			for (i = 0; i < 6; ++i)
990 				out_8(&mr->fifo, 0);
991 		}
992 		break;
993 	case dataing:
994 		/* transfer data, if any */
995 		if (!ms->dma_started) {
996 			set_dma_cmds(ms, cmd);
997 			out_le32(&md->cmdptr, virt_to_phys(ms->dma_cmds));
998 			out_le32(&md->control, (RUN << 16) | RUN);
999 			ms->dma_started = 1;
1000 		}
1001 		nb = ms->dma_count;
1002 		if (nb > 0xfff0)
1003 			nb = 0xfff0;
1004 		ms->dma_count -= nb;
1005 		ms->data_ptr += nb;
1006 		out_8(&mr->count_lo, nb);
1007 		out_8(&mr->count_hi, nb >> 8);
1008 		out_8(&mr->sequence, (tp->data_goes_out?
1009 				SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
1010 		break;
1011 	case statusing:
1012 		out_8(&mr->count_hi, 0);
1013 		out_8(&mr->count_lo, 1);
1014 		out_8(&mr->sequence, SEQ_STATUS + seq);
1015 		break;
1016 	case busfreeing:
1017 	case disconnecting:
1018 		out_8(&mr->sequence, SEQ_ENBRESEL);
1019 		udelay(1);
1020 		dlog(ms, "enbresel intr/exc/err/fc=%.8x",
1021 		     MKWORD(mr->interrupt, mr->exception, mr->error,
1022 			    mr->fifo_count));
1023 		out_8(&mr->sequence, SEQ_BUSFREE);
1024 		break;
1025 	default:
1026 		printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
1027 		       ms->phase);
1028 		dumpslog(ms);
1029 	}
1030 
1031 }
1032 
1033 static inline void
get_msgin(struct mesh_state * ms)1034 get_msgin(struct mesh_state *ms)
1035 {
1036 	volatile struct mesh_regs *mr = ms->mesh;
1037 	int i, n;
1038 
1039 	n = mr->fifo_count;
1040 	if (n != 0) {
1041 		i = ms->n_msgin;
1042 		ms->n_msgin = i + n;
1043 		for (; n > 0; --n)
1044 			ms->msgin[i++] = in_8(&mr->fifo);
1045 	}
1046 }
1047 
1048 static inline int
msgin_length(struct mesh_state * ms)1049 msgin_length(struct mesh_state *ms)
1050 {
1051 	int b, n;
1052 
1053 	n = 1;
1054 	if (ms->n_msgin > 0) {
1055 		b = ms->msgin[0];
1056 		if (b == 1) {
1057 			/* extended message */
1058 			n = ms->n_msgin < 2? 2: ms->msgin[1] + 2;
1059 		} else if (0x20 <= b && b <= 0x2f) {
1060 			/* 2-byte message */
1061 			n = 2;
1062 		}
1063 	}
1064 	return n;
1065 }
1066 
1067 static void
cmd_complete(struct mesh_state * ms)1068 cmd_complete(struct mesh_state *ms)
1069 {
1070 	volatile struct mesh_regs *mr = ms->mesh;
1071 	Scsi_Cmnd *cmd = ms->current_req;
1072 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1073 	int seq, n, t;
1074 
1075 	dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
1076 	seq = use_active_neg + (ms->n_msgout? SEQ_ATN: 0);
1077 	switch (ms->msgphase) {
1078 	case msg_out_xxx:
1079 		/* huh?  we expected a phase mismatch */
1080 		ms->n_msgin = 0;
1081 		ms->msgphase = msg_in;
1082 		/* fall through */
1083 
1084 	case msg_in:
1085 		/* should have some message bytes in fifo */
1086 		get_msgin(ms);
1087 		n = msgin_length(ms);
1088 		if (ms->n_msgin < n) {
1089 			out_8(&mr->count_lo, n - ms->n_msgin);
1090 			out_8(&mr->sequence, SEQ_MSGIN + seq);
1091 		} else {
1092 			ms->msgphase = msg_none;
1093 			handle_msgin(ms);
1094 			start_phase(ms);
1095 		}
1096 		break;
1097 
1098 	case msg_in_bad:
1099 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1100 		udelay(1);
1101 		out_8(&mr->count_lo, 1);
1102 		out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + use_active_neg);
1103 		break;
1104 
1105 	case msg_out:
1106 		/*
1107 		 * To get the right timing on ATN wrt ACK, we have
1108 		 * to get the MESH to drop ACK, wait until REQ gets
1109 		 * asserted, then drop ATN.  To do this we first
1110 		 * issue a SEQ_MSGOUT with ATN and wait for REQ,
1111 		 * then change the command to a SEQ_MSGOUT w/o ATN.
1112 		 * If we don't see REQ in a reasonable time, we
1113 		 * change the command to SEQ_MSGIN with ATN,
1114 		 * wait for the phase mismatch interrupt, then
1115 		 * issue the SEQ_MSGOUT without ATN.
1116 		 */
1117 		out_8(&mr->count_lo, 1);
1118 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg + SEQ_ATN);
1119 		t = 30;		/* wait up to 30us */
1120 		while ((mr->bus_status0 & BS0_REQ) == 0 && --t >= 0)
1121 			udelay(1);
1122 		dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
1123 		     MKWORD(mr->error, mr->exception,
1124 			    mr->fifo_count, mr->count_lo));
1125 		if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
1126 			/* whoops, target didn't do what we expected */
1127 			ms->last_n_msgout = ms->n_msgout;
1128 			ms->n_msgout = 0;
1129 			if (in_8(&mr->interrupt) & INT_ERROR) {
1130 				printk(KERN_ERR "mesh: error %x in msg_out\n",
1131 				       in_8(&mr->error));
1132 				handle_error(ms);
1133 				return;
1134 			}
1135 			if (in_8(&mr->exception) != EXC_PHASEMM)
1136 				printk(KERN_ERR "mesh: exc %x in msg_out\n",
1137 				       in_8(&mr->exception));
1138 			else
1139 				printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
1140 				       in_8(&mr->bus_status0));
1141 			handle_exception(ms);
1142 			return;
1143 		}
1144 		if (mr->bus_status0 & BS0_REQ) {
1145 			out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1146 			udelay(1);
1147 			out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1148 			ms->msgphase = msg_out_last;
1149 		} else {
1150 			out_8(&mr->sequence, SEQ_MSGIN + use_active_neg + SEQ_ATN);
1151 			ms->msgphase = msg_out_xxx;
1152 		}
1153 		break;
1154 
1155 	case msg_out_last:
1156 		ms->last_n_msgout = ms->n_msgout;
1157 		ms->n_msgout = 0;
1158 		ms->msgphase = ms->expect_reply? msg_in: msg_none;
1159 		start_phase(ms);
1160 		break;
1161 
1162 	case msg_none:
1163 		switch (ms->phase) {
1164 		case idle:
1165 			printk(KERN_ERR "mesh: interrupt in idle phase?\n");
1166 			dumpslog(ms);
1167 			return;
1168 		case selecting:
1169 			dlog(ms, "Selecting phase at command completion",0);
1170 			ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
1171 						 (cmd? cmd->lun: 0));
1172 			ms->n_msgout = 1;
1173 			ms->expect_reply = 0;
1174 			if (ms->aborting) {
1175 				ms->msgout[0] = ABORT;
1176 				ms->n_msgout++;
1177 			} else if (tp->sdtr_state == do_sdtr) {
1178 				/* add SDTR message */
1179 				add_sdtr_msg(ms);
1180 				ms->expect_reply = 1;
1181 				tp->sdtr_state = sdtr_sent;
1182 			}
1183 			ms->msgphase = msg_out;
1184 			/*
1185 			 * We need to wait for REQ before dropping ATN.
1186 			 * We wait for at most 30us, then fall back to
1187 			 * a scheme where we issue a SEQ_COMMAND with ATN,
1188 			 * which will give us a phase mismatch interrupt
1189 			 * when REQ does come, and then we send the message.
1190 			 */
1191 			t = 230;		/* wait up to 230us */
1192 			while ((mr->bus_status0 & BS0_REQ) == 0) {
1193 				if (--t < 0) {
1194 					dlog(ms, "impatient for req", ms->n_msgout);
1195 					ms->msgphase = msg_none;
1196 					break;
1197 				}
1198 				udelay(1);
1199 			}
1200 			break;
1201 		case dataing:
1202 			if (ms->dma_count != 0) {
1203 				start_phase(ms);
1204 				return;
1205 			}
1206 			/*
1207 			 * We can get a phase mismatch here if the target
1208 			 * changes to the status phase, even though we have
1209 			 * had a command complete interrupt.  Then, if we
1210 			 * issue the SEQ_STATUS command, we'll get a sequence
1211 			 * error interrupt.  Which isn't so bad except that
1212 			 * occasionally the mesh actually executes the
1213 			 * SEQ_STATUS *as well as* giving us the sequence
1214 			 * error and phase mismatch exception.
1215 			 */
1216 			out_8(&mr->sequence, 0);
1217 			out_8(&mr->interrupt,
1218 			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1219 			halt_dma(ms);
1220 			break;
1221 		case statusing:
1222 			if (cmd) {
1223 				cmd->SCp.Status = mr->fifo;
1224 				if (DEBUG_TARGET(cmd))
1225 					printk(KERN_DEBUG "mesh: status is %x\n",
1226 					       cmd->SCp.Status);
1227 			}
1228 			ms->msgphase = msg_in;
1229 			break;
1230 		case busfreeing:
1231 			mesh_done(ms, 1);
1232 			return;
1233 		case disconnecting:
1234 			ms->current_req = 0;
1235 			ms->phase = idle;
1236 			mesh_start(ms);
1237 			return;
1238 		default:
1239 			break;
1240 		}
1241 		++ms->phase;
1242 		start_phase(ms);
1243 		break;
1244 	}
1245 }
1246 
phase_mismatch(struct mesh_state * ms)1247 static void phase_mismatch(struct mesh_state *ms)
1248 {
1249 	volatile struct mesh_regs *mr = ms->mesh;
1250 	int phase;
1251 
1252 	dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
1253 	     MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
1254 	phase = mr->bus_status0 & BS0_PHASE;
1255 	if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
1256 		/* output the last byte of the message, without ATN */
1257 		out_8(&mr->count_lo, 1);
1258 		out_8(&mr->sequence, SEQ_MSGOUT + use_active_neg);
1259 		udelay(1);
1260 		out_8(&mr->fifo, ms->msgout[ms->n_msgout-1]);
1261 		ms->msgphase = msg_out_last;
1262 		return;
1263 	}
1264 
1265 	if (ms->msgphase == msg_in) {
1266 		get_msgin(ms);
1267 		if (ms->n_msgin)
1268 			handle_msgin(ms);
1269 	}
1270 
1271 	if (ms->dma_started)
1272 		halt_dma(ms);
1273 	if (mr->fifo_count) {
1274 		out_8(&mr->sequence, SEQ_FLUSHFIFO);
1275 		udelay(1);
1276 	}
1277 
1278 	ms->msgphase = msg_none;
1279 	switch (phase) {
1280 	case BP_DATAIN:
1281 		ms->tgts[ms->conn_tgt].data_goes_out = 0;
1282 		ms->phase = dataing;
1283 		break;
1284 	case BP_DATAOUT:
1285 		ms->tgts[ms->conn_tgt].data_goes_out = 1;
1286 		ms->phase = dataing;
1287 		break;
1288 	case BP_COMMAND:
1289 		ms->phase = commanding;
1290 		break;
1291 	case BP_STATUS:
1292 		ms->phase = statusing;
1293 		break;
1294 	case BP_MSGIN:
1295 		ms->msgphase = msg_in;
1296 		ms->n_msgin = 0;
1297 		break;
1298 	case BP_MSGOUT:
1299 		ms->msgphase = msg_out;
1300 		if (ms->n_msgout == 0) {
1301 			if (ms->aborting) {
1302 				do_abort(ms);
1303 			} else {
1304 				if (ms->last_n_msgout == 0) {
1305 					printk(KERN_DEBUG
1306 					       "mesh: no msg to repeat\n");
1307 					ms->msgout[0] = NOP;
1308 					ms->last_n_msgout = 1;
1309 				}
1310 				ms->n_msgout = ms->last_n_msgout;
1311 			}
1312 		}
1313 		break;
1314 	default:
1315 		printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
1316 		ms->stat = DID_ERROR;
1317 		mesh_done(ms, 1);
1318 		return;
1319 	}
1320 
1321 	start_phase(ms);
1322 }
1323 
1324 static void
reselected(struct mesh_state * ms)1325 reselected(struct mesh_state *ms)
1326 {
1327 	volatile struct mesh_regs *mr = ms->mesh;
1328 	Scsi_Cmnd *cmd;
1329 	struct mesh_target *tp;
1330 	int b, t, prev;
1331 
1332 	switch (ms->phase) {
1333 	case idle:
1334 		break;
1335 	case arbitrating:
1336 		if ((cmd = ms->current_req) != NULL) {
1337 			/* put the command back on the queue */
1338 			cmd->host_scribble = (void *) ms->request_q;
1339 			if (ms->request_q == NULL)
1340 				ms->request_qtail = cmd;
1341 			ms->request_q = cmd;
1342 			tp = &ms->tgts[cmd->target];
1343 			tp->current_req = NULL;
1344 		}
1345 		break;
1346 	case busfreeing:
1347 		ms->phase = reselecting;
1348 		mesh_done(ms, 0);
1349 		break;
1350 	case disconnecting:
1351 		break;
1352 	default:
1353 		printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
1354 		       ms->msgphase, ms->phase, ms->conn_tgt);
1355 		dumplog(ms, ms->conn_tgt);
1356 		dumpslog(ms);
1357 	}
1358 
1359 	if (ms->dma_started) {
1360 		printk(KERN_ERR "mesh: reselected with DMA started !\n");
1361 		halt_dma(ms);
1362 	}
1363 	ms->current_req = NULL;
1364 	ms->phase = dataing;
1365 	ms->msgphase = msg_in;
1366 	ms->n_msgout = 0;
1367 	ms->last_n_msgout = 0;
1368 	prev = ms->conn_tgt;
1369 
1370 	/*
1371 	 * We seem to get abortive reselections sometimes.
1372 	 */
1373 	while ((mr->bus_status1 & BS1_BSY) == 0) {
1374 		static int mesh_aborted_resels;
1375 		mesh_aborted_resels++;
1376 		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1377 		udelay(1);
1378 		out_8(&mr->sequence, SEQ_ENBRESEL);
1379 		udelay(5);
1380 		dlog(ms, "extra resel err/exc/fc = %.6x",
1381 		     MKWORD(0, mr->error, mr->exception, mr->fifo_count));
1382 	}
1383 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1384 	udelay(1);
1385 	out_8(&mr->sequence, SEQ_ENBRESEL);
1386 	udelay(1);
1387 	out_8(&mr->sync_params, ASYNC_PARAMS);
1388 
1389 	/*
1390 	 * Find out who reselected us.
1391 	 */
1392 	if (mr->fifo_count == 0) {
1393 		printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
1394 		ms->conn_tgt = ms->host->this_id;
1395 		goto bogus;
1396 	}
1397 	/* get the last byte in the fifo */
1398 	do {
1399 		b = in_8(&mr->fifo);
1400 		dlog(ms, "reseldata %x", b);
1401 	} while (in_8(&mr->fifo_count));
1402 	for (t = 0; t < 8; ++t)
1403 		if ((b & (1 << t)) != 0 && t != ms->host->this_id)
1404 			break;
1405 	if (b != (1 << t) + (1 << ms->host->this_id)) {
1406 		printk(KERN_ERR "mesh: bad reselection data %x\n", b);
1407 		ms->conn_tgt = ms->host->this_id;
1408 		goto bogus;
1409 	}
1410 
1411 
1412 	/*
1413 	 * Set up to continue with that target's transfer.
1414 	 */
1415 	ms->conn_tgt = t;
1416 	tp = &ms->tgts[t];
1417 	out_8(&mr->sync_params, tp->sync_params);
1418 	if (ALLOW_DEBUG(t)) {
1419 		printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
1420 		printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
1421 		       tp->saved_ptr, tp->data_goes_out, tp->current_req);
1422 	}
1423 	ms->current_req = tp->current_req;
1424 	if (tp->current_req == NULL) {
1425 		printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
1426 		goto bogus;
1427 	}
1428 	ms->data_ptr = tp->saved_ptr;
1429 	dlog(ms, "resel prev tgt=%d", prev);
1430 	dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
1431 	start_phase(ms);
1432 	return;
1433 
1434 bogus:
1435 	dumplog(ms, ms->conn_tgt);
1436 	dumpslog(ms);
1437 	ms->data_ptr = 0;
1438 	ms->aborting = 1;
1439 	start_phase(ms);
1440 }
1441 
do_abort(struct mesh_state * ms)1442 static void do_abort(struct mesh_state *ms)
1443 {
1444 	ms->msgout[0] = ABORT;
1445 	ms->n_msgout = 1;
1446 	ms->aborting = 1;
1447 	ms->stat = DID_ABORT;
1448 	dlog(ms, "abort", 0);
1449 }
1450 
1451 static void
handle_reset(struct mesh_state * ms)1452 handle_reset(struct mesh_state *ms)
1453 {
1454 	int tgt;
1455 	struct mesh_target *tp;
1456 	Scsi_Cmnd *cmd;
1457 	volatile struct mesh_regs *mr = ms->mesh;
1458 
1459 	for (tgt = 0; tgt < 8; ++tgt) {
1460 		tp = &ms->tgts[tgt];
1461 		if ((cmd = tp->current_req) != NULL) {
1462 			cmd->result = DID_RESET << 16;
1463 			tp->current_req = NULL;
1464 			mesh_completed(ms, cmd);
1465 		}
1466 		ms->tgts[tgt].sdtr_state = do_sdtr;
1467 		ms->tgts[tgt].sync_params = ASYNC_PARAMS;
1468 	}
1469 	ms->current_req = NULL;
1470 	while ((cmd = ms->request_q) != NULL) {
1471 		ms->request_q = (Scsi_Cmnd *) cmd->host_scribble;
1472 		cmd->result = DID_RESET << 16;
1473 		mesh_completed(ms, cmd);
1474 	}
1475 	ms->phase = idle;
1476 	ms->msgphase = msg_none;
1477 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1478 	out_8(&mr->sequence, SEQ_FLUSHFIFO);
1479 	udelay(1);
1480 	out_8(&mr->sync_params, ASYNC_PARAMS);
1481 	out_8(&mr->sequence, SEQ_ENBRESEL);
1482 }
1483 
1484 static void
do_mesh_interrupt(int irq,void * dev_id,struct pt_regs * ptregs)1485 do_mesh_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
1486 {
1487 	unsigned long flags;
1488 
1489 	spin_lock_irqsave(&io_request_lock, flags);
1490 	mesh_interrupt(irq, dev_id, ptregs);
1491 	spin_unlock_irqrestore(&io_request_lock, flags);
1492 }
1493 
handle_error(struct mesh_state * ms)1494 static void handle_error(struct mesh_state *ms)
1495 {
1496 	int err, exc, count;
1497 	volatile struct mesh_regs *mr = ms->mesh;
1498 
1499 	err = in_8(&mr->error);
1500 	exc = in_8(&mr->exception);
1501 	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
1502 	dlog(ms, "error err/exc/fc/cl=%.8x",
1503 	     MKWORD(err, exc, mr->fifo_count, mr->count_lo));
1504 	if (err & ERR_SCSIRESET) {
1505 		/* SCSI bus was reset */
1506 		printk(KERN_INFO "mesh: SCSI bus reset detected: "
1507 		       "waiting for end...");
1508 		while ((mr->bus_status1 & BS1_RST) != 0)
1509 			udelay(1);
1510 		printk("done\n");
1511 		handle_reset(ms);
1512 		/* request_q is empty, no point in mesh_start() */
1513 		return;
1514 	}
1515 	if (err & ERR_UNEXPDISC) {
1516 		/* Unexpected disconnect */
1517 		if (exc & EXC_RESELECTED) {
1518 			reselected(ms);
1519 			return;
1520 		}
1521 		if (!ms->aborting) {
1522 			printk(KERN_WARNING "mesh: target %d aborted\n",
1523 			       ms->conn_tgt);
1524 			dumplog(ms, ms->conn_tgt);
1525 			dumpslog(ms);
1526 		}
1527 		out_8(&mr->interrupt, INT_CMDDONE);
1528 		ms->stat = DID_ABORT;
1529 		mesh_done(ms, 1);
1530 		return;
1531 	}
1532 	if (err & ERR_PARITY) {
1533 		if (ms->msgphase == msg_in) {
1534 			printk(KERN_ERR "mesh: msg parity error, target %d\n",
1535 			       ms->conn_tgt);
1536 			ms->msgout[0] = MSG_PARITY_ERROR;
1537 			ms->n_msgout = 1;
1538 			ms->msgphase = msg_in_bad;
1539 			cmd_complete(ms);
1540 			return;
1541 		}
1542 		if (ms->stat == DID_OK) {
1543 			printk(KERN_ERR "mesh: parity error, target %d\n",
1544 			       ms->conn_tgt);
1545 			ms->stat = DID_PARITY;
1546 		}
1547 		count = (mr->count_hi << 8) + mr->count_lo;
1548 		if (count == 0) {
1549 			cmd_complete(ms);
1550 		} else {
1551 			/* reissue the data transfer command */
1552 			out_8(&mr->sequence, mr->sequence);
1553 		}
1554 		return;
1555 	}
1556 	if (err & ERR_SEQERR) {
1557 		if (exc & EXC_RESELECTED) {
1558 			/* This can happen if we issue a command to
1559 			   get the bus just after the target reselects us. */
1560 			static int mesh_resel_seqerr;
1561 			mesh_resel_seqerr++;
1562 			reselected(ms);
1563 			return;
1564 		}
1565 		if (exc == EXC_PHASEMM) {
1566 			static int mesh_phasemm_seqerr;
1567 			mesh_phasemm_seqerr++;
1568 			phase_mismatch(ms);
1569 			return;
1570 		}
1571 		printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
1572 		       err, exc);
1573 	} else {
1574 		printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
1575 	}
1576 	mesh_dump_regs(ms);
1577 	dumplog(ms, ms->conn_tgt);
1578 	if (ms->phase > selecting && (mr->bus_status1 & BS1_BSY)) {
1579 		/* try to do what the target wants */
1580 		do_abort(ms);
1581 		phase_mismatch(ms);
1582 		return;
1583 	}
1584 	ms->stat = DID_ERROR;
1585 	mesh_done(ms, 1);
1586 }
1587 
handle_exception(struct mesh_state * ms)1588 static void handle_exception(struct mesh_state *ms)
1589 {
1590 	int exc;
1591 	volatile struct mesh_regs *mr = ms->mesh;
1592 
1593 	exc = in_8(&mr->exception);
1594 	out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
1595 	if (exc & EXC_RESELECTED) {
1596 		static int mesh_resel_exc;
1597 		mesh_resel_exc++;
1598 		reselected(ms);
1599 	} else if (exc == EXC_ARBLOST) {
1600 		printk(KERN_DEBUG "mesh: lost arbitration\n");
1601 		ms->stat = DID_BUS_BUSY;
1602 		mesh_done(ms, 1);
1603 	} else if (exc == EXC_SELTO) {
1604 		/* selection timed out */
1605 		ms->stat = DID_BAD_TARGET;
1606 		mesh_done(ms, 1);
1607 	} else if (exc == EXC_PHASEMM) {
1608 		/* target wants to do something different:
1609 		   find out what it wants and do it. */
1610 		phase_mismatch(ms);
1611 	} else {
1612 		printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
1613 		mesh_dump_regs(ms);
1614 		dumplog(ms, ms->conn_tgt);
1615 		do_abort(ms);
1616 		phase_mismatch(ms);
1617 	}
1618 }
1619 
1620 static void
mesh_interrupt(int irq,void * dev_id,struct pt_regs * ptregs)1621 mesh_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
1622 {
1623 	struct mesh_state *ms = (struct mesh_state *) dev_id;
1624 	volatile struct mesh_regs *mr = ms->mesh;
1625 	int intr;
1626 
1627 #if 0
1628 	if (ALLOW_DEBUG(ms->conn_tgt))
1629 		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
1630 		       "phase=%d msgphase=%d\n", mr->bus_status0,
1631 		       mr->interrupt, mr->exception, mr->error,
1632 		       ms->phase, ms->msgphase);
1633 #endif
1634 	while ((intr = in_8(&mr->interrupt)) != 0) {
1635 		dlog(ms, "interrupt intr/err/exc/seq=%.8x",
1636 		     MKWORD(intr, mr->error, mr->exception, mr->sequence));
1637 		if (intr & INT_ERROR) {
1638 			handle_error(ms);
1639 		} else if (intr & INT_EXCEPTION) {
1640 			handle_exception(ms);
1641 		} else if (intr & INT_CMDDONE) {
1642 			out_8(&mr->interrupt, INT_CMDDONE);
1643 			cmd_complete(ms);
1644 		}
1645 	}
1646 }
1647 
1648 static void
handle_msgin(struct mesh_state * ms)1649 handle_msgin(struct mesh_state *ms)
1650 {
1651 	int i, code;
1652 	Scsi_Cmnd *cmd = ms->current_req;
1653 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1654 
1655 	if (ms->n_msgin == 0)
1656 		return;
1657 	code = ms->msgin[0];
1658 	if (ALLOW_DEBUG(ms->conn_tgt)) {
1659 		printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
1660 		for (i = 0; i < ms->n_msgin; ++i)
1661 			printk(" %x", ms->msgin[i]);
1662 		printk("\n");
1663 	}
1664 	dlog(ms, "msgin msg=%.8x",
1665 	     MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
1666 
1667 	ms->expect_reply = 0;
1668 	ms->n_msgout = 0;
1669 	if (ms->n_msgin < msgin_length(ms))
1670 		goto reject;
1671 	if (cmd)
1672 		cmd->SCp.Message = code;
1673 	switch (code) {
1674 	case COMMAND_COMPLETE:
1675 		break;
1676 	case EXTENDED_MESSAGE:
1677 		switch (ms->msgin[2]) {
1678 		case EXTENDED_MODIFY_DATA_POINTER:
1679 			ms->data_ptr += (ms->msgin[3] << 24) + ms->msgin[6]
1680 				+ (ms->msgin[4] << 16) + (ms->msgin[5] << 8);
1681 			break;
1682 		case EXTENDED_SDTR:
1683 			if (tp->sdtr_state != sdtr_sent) {
1684 				/* reply with an SDTR */
1685 				add_sdtr_msg(ms);
1686 				/* limit period to at least his value,
1687 				   offset to no more than his */
1688 				if (ms->msgout[3] < ms->msgin[3])
1689 					ms->msgout[3] = ms->msgin[3];
1690 				if (ms->msgout[4] > ms->msgin[4])
1691 					ms->msgout[4] = ms->msgin[4];
1692 				set_sdtr(ms, ms->msgout[3], ms->msgout[4]);
1693 				ms->msgphase = msg_out;
1694 			} else {
1695 				set_sdtr(ms, ms->msgin[3], ms->msgin[4]);
1696 			}
1697 			break;
1698 		default:
1699 			goto reject;
1700 		}
1701 		break;
1702 	case SAVE_POINTERS:
1703 		tp->saved_ptr = ms->data_ptr;
1704 		break;
1705 	case RESTORE_POINTERS:
1706 		ms->data_ptr = tp->saved_ptr;
1707 		break;
1708 	case DISCONNECT:
1709 		ms->phase = disconnecting;
1710 		break;
1711 	case ABORT:
1712 		break;
1713 	case MESSAGE_REJECT:
1714 		if (tp->sdtr_state == sdtr_sent)
1715 			set_sdtr(ms, 0, 0);
1716 		break;
1717 	case NOP:
1718 		break;
1719 	default:
1720 		if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
1721 			if (cmd == NULL) {
1722 				do_abort(ms);
1723 				ms->msgphase = msg_out;
1724 			} else if (code != cmd->lun + IDENTIFY_BASE) {
1725 				printk(KERN_WARNING "mesh: lun mismatch "
1726 				       "(%d != %d) on reselection from "
1727 				       "target %d\n", i, cmd->lun,
1728 				       ms->conn_tgt);
1729 			}
1730 			break;
1731 		}
1732 		goto reject;
1733 	}
1734 	return;
1735 
1736  reject:
1737 	printk(KERN_WARNING "mesh: rejecting message from target %d:",
1738 	       ms->conn_tgt);
1739 	for (i = 0; i < ms->n_msgin; ++i)
1740 		printk(" %x", ms->msgin[i]);
1741 	printk("\n");
1742 	ms->msgout[0] = MESSAGE_REJECT;
1743 	ms->n_msgout = 1;
1744 	ms->msgphase = msg_out;
1745 }
1746 
1747 static void
mesh_done(struct mesh_state * ms,int start_next)1748 mesh_done(struct mesh_state *ms, int start_next)
1749 {
1750 	Scsi_Cmnd *cmd;
1751 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1752 
1753 	cmd = ms->current_req;
1754 	ms->current_req = 0;
1755 	tp->current_req = 0;
1756 	if (cmd) {
1757 		cmd->result = (ms->stat << 16) + cmd->SCp.Status;
1758 		if (ms->stat == DID_OK)
1759 			cmd->result += (cmd->SCp.Message << 8);
1760 		if (DEBUG_TARGET(cmd)) {
1761 			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
1762 			       cmd->result, ms->data_ptr, cmd->request_bufflen);
1763 			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
1764 			    && cmd->request_buffer != 0) {
1765 				unsigned char *b = cmd->request_buffer;
1766 				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
1767 				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
1768 			}
1769 		}
1770 		cmd->SCp.this_residual -= ms->data_ptr;
1771 		mesh_completed(ms, cmd);
1772 	}
1773 	if (start_next) {
1774 		out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
1775 		udelay(1);
1776 		ms->phase = idle;
1777 		mesh_start(ms);
1778 	}
1779 }
1780 
1781 static void
mesh_completed(struct mesh_state * ms,Scsi_Cmnd * cmd)1782 mesh_completed(struct mesh_state *ms, Scsi_Cmnd *cmd)
1783 {
1784 	(*cmd->scsi_done)(cmd);
1785 }
1786 
1787 /*
1788  * Set up DMA commands for transferring data.
1789  */
1790 static void
set_dma_cmds(struct mesh_state * ms,Scsi_Cmnd * cmd)1791 set_dma_cmds(struct mesh_state *ms, Scsi_Cmnd *cmd)
1792 {
1793 	int i, dma_cmd, total, off, dtot;
1794 	struct scatterlist *scl;
1795 	struct dbdma_cmd *dcmds;
1796 
1797 	dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
1798 		OUTPUT_MORE: INPUT_MORE;
1799 	dcmds = ms->dma_cmds;
1800 	dtot = 0;
1801 	if (cmd) {
1802 		cmd->SCp.this_residual = cmd->request_bufflen;
1803 		if (cmd->use_sg > 0) {
1804 			int nseg;
1805 			total = 0;
1806 			scl = (struct scatterlist *) cmd->buffer;
1807 			off = ms->data_ptr;
1808 			nseg = pci_map_sg(ms->pdev, scl, cmd->use_sg,
1809 				 scsi_to_pci_dma_dir(cmd ->sc_data_direction));
1810 			for (i = 0; i <nseg; ++i, ++scl) {
1811 				u32 dma_addr = sg_dma_address(scl);
1812 				u32 dma_len = sg_dma_len(scl);
1813 
1814 				total += scl->length;
1815 				if (off >= dma_len) {
1816 					off -= dma_len;
1817 					continue;
1818 				}
1819 				if (dma_len > 0xffff)
1820 					panic("mesh: scatterlist element >= 64k");
1821 				st_le16(&dcmds->req_count, dma_len - off);
1822 				st_le16(&dcmds->command, dma_cmd);
1823 				st_le32(&dcmds->phy_addr, dma_addr + off);
1824 				dcmds->xfer_status = 0;
1825 				++dcmds;
1826 				dtot += dma_len - off;
1827 				off = 0;
1828 			}
1829 		} else if (ms->data_ptr < cmd->request_bufflen) {
1830 			dtot = cmd->request_bufflen - ms->data_ptr;
1831 			if (dtot > 0xffff)
1832 				panic("mesh: transfer size >= 64k");
1833 			st_le16(&dcmds->req_count, dtot);
1834 			/* XXX Use pci DMA API here ... */
1835 			st_le32(&dcmds->phy_addr,
1836 				virt_to_phys(cmd->request_buffer) + ms->data_ptr);
1837 			dcmds->xfer_status = 0;
1838 			++dcmds;
1839 		}
1840 	}
1841 	if (dtot == 0) {
1842 		/* Either the target has overrun our buffer,
1843 		   or the caller didn't provide a buffer. */
1844 		static char mesh_extra_buf[64];
1845 
1846 		dtot = sizeof(mesh_extra_buf);
1847 		st_le16(&dcmds->req_count, dtot);
1848 		st_le32(&dcmds->phy_addr, virt_to_phys(mesh_extra_buf));
1849 		dcmds->xfer_status = 0;
1850 		++dcmds;
1851 	}
1852 	dma_cmd += OUTPUT_LAST - OUTPUT_MORE;
1853 	st_le16(&dcmds[-1].command, dma_cmd);
1854 	memset(dcmds, 0, sizeof(*dcmds));
1855 	st_le16(&dcmds->command, DBDMA_STOP);
1856 	ms->dma_count = dtot;
1857 }
1858 
1859 static void
halt_dma(struct mesh_state * ms)1860 halt_dma(struct mesh_state *ms)
1861 {
1862 	volatile struct dbdma_regs *md = ms->dma;
1863 	volatile struct mesh_regs *mr = ms->mesh;
1864 	Scsi_Cmnd *cmd = ms->current_req;
1865 	int t, nb;
1866 
1867 	if (!ms->tgts[ms->conn_tgt].data_goes_out) {
1868 		/* wait a little while until the fifo drains */
1869 		t = 50;
1870 		while (t > 0 && mr->fifo_count != 0
1871 		       && (in_le32(&md->status) & ACTIVE) != 0) {
1872 			--t;
1873 			udelay(1);
1874 		}
1875 	}
1876 	out_le32(&md->control, RUN << 16);	/* turn off RUN bit */
1877 	nb = (mr->count_hi << 8) + mr->count_lo;
1878 	dlog(ms, "halt_dma fc/count=%.6x",
1879 	     MKWORD(0, mr->fifo_count, 0, nb));
1880 	if (ms->tgts[ms->conn_tgt].data_goes_out)
1881 		nb += mr->fifo_count;
1882 	/* nb is the number of bytes not yet transferred
1883 	   to/from the target. */
1884 	ms->data_ptr -= nb;
1885 	dlog(ms, "data_ptr %x", ms->data_ptr);
1886 	if (ms->data_ptr < 0) {
1887 		printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
1888 		       ms->data_ptr, nb, ms);
1889 		ms->data_ptr = 0;
1890 #ifdef MESH_DBG
1891 		dumplog(ms, ms->conn_tgt);
1892 		dumpslog(ms);
1893 #endif /* MESH_DBG */
1894 	} else if (cmd && cmd->request_bufflen != 0 &&
1895 		   ms->data_ptr > cmd->request_bufflen) {
1896 		printk(KERN_DEBUG "mesh: target %d overrun, "
1897 		       "data_ptr=%x total=%x goes_out=%d\n",
1898 		       ms->conn_tgt, ms->data_ptr, cmd->request_bufflen,
1899 		       ms->tgts[ms->conn_tgt].data_goes_out);
1900 	}
1901 	if (cmd->use_sg != 0) {
1902 		struct scatterlist *sg;
1903 		sg = (struct scatterlist *)cmd->request_buffer;
1904 		pci_unmap_sg(ms->pdev, sg, cmd->use_sg,
1905 			     scsi_to_pci_dma_dir(cmd->sc_data_direction));
1906 	}
1907 	ms->dma_started = 0;
1908 }
1909 
1910 /*
1911  * Work out whether we expect data to go out from the host adaptor or into it.
1912  * (If this information is available from somewhere else in the scsi
1913  * code, somebody please let me know :-)
1914  */
1915 static int
data_goes_out(Scsi_Cmnd * cmd)1916 data_goes_out(Scsi_Cmnd *cmd)
1917 {
1918 	switch (cmd->cmnd[0]) {
1919 	case CHANGE_DEFINITION:
1920 	case COMPARE:
1921 	case COPY:
1922 	case COPY_VERIFY:
1923 	case FORMAT_UNIT:
1924 	case LOG_SELECT:
1925 	case MEDIUM_SCAN:
1926 	case MODE_SELECT:
1927 	case MODE_SELECT_10:
1928 	case REASSIGN_BLOCKS:
1929 	case RESERVE:
1930 	case SEARCH_EQUAL:
1931 	case SEARCH_EQUAL_12:
1932 	case SEARCH_HIGH:
1933 	case SEARCH_HIGH_12:
1934 	case SEARCH_LOW:
1935 	case SEARCH_LOW_12:
1936 	case SEND_DIAGNOSTIC:
1937 	case SEND_VOLUME_TAG:
1938 	case SET_WINDOW:
1939 	case UPDATE_BLOCK:
1940 	case WRITE_BUFFER:
1941  	case WRITE_6:
1942 	case WRITE_10:
1943 	case WRITE_12:
1944 	case WRITE_LONG:
1945 	case WRITE_LONG_2:      /* alternate code for WRITE_LONG */
1946 	case WRITE_SAME:
1947 	case WRITE_VERIFY:
1948 	case WRITE_VERIFY_12:
1949 		return 1;
1950 	default:
1951 		return 0;
1952 	}
1953 }
1954 
1955 #ifdef MESH_DBG
readtb(void)1956 static inline u32 readtb(void)
1957 {
1958 	u32 tb;
1959 
1960 #ifdef DBG_USE_TB
1961 	/* Beware: if you enable this, it will crash on 601s. */
1962 	asm ("mftb %0" : "=r" (tb) : );
1963 #else
1964 	tb = 0;
1965 #endif
1966 	return tb;
1967 }
1968 
dlog(struct mesh_state * ms,char * fmt,int a)1969 static void dlog(struct mesh_state *ms, char *fmt, int a)
1970 {
1971 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
1972 	struct dbglog *tlp, *slp;
1973 
1974 	tlp = &tp->log[tp->log_ix];
1975 	slp = &ms->log[ms->log_ix];
1976 	tlp->fmt = fmt;
1977 	tlp->tb = readtb();
1978 	tlp->phase = (ms->msgphase << 4) + ms->phase;
1979 	tlp->bs0 = ms->mesh->bus_status0;
1980 	tlp->bs1 = ms->mesh->bus_status1;
1981 	tlp->tgt = ms->conn_tgt;
1982 	tlp->d = a;
1983 	*slp = *tlp;
1984 	if (++tp->log_ix >= N_DBG_LOG)
1985 		tp->log_ix = 0;
1986 	if (tp->n_log < N_DBG_LOG)
1987 		++tp->n_log;
1988 	if (++ms->log_ix >= N_DBG_SLOG)
1989 		ms->log_ix = 0;
1990 	if (ms->n_log < N_DBG_SLOG)
1991 		++ms->n_log;
1992 }
1993 
dumplog(struct mesh_state * ms,int t)1994 static void dumplog(struct mesh_state *ms, int t)
1995 {
1996 	struct mesh_target *tp = &ms->tgts[t];
1997 	struct dbglog *lp;
1998 	int i;
1999 
2000 	if (tp->n_log == 0)
2001 		return;
2002 	i = tp->log_ix - tp->n_log;
2003 	if (i < 0)
2004 		i += N_DBG_LOG;
2005 	tp->n_log = 0;
2006 	do {
2007 		lp = &tp->log[i];
2008 		printk(KERN_DEBUG "mesh log %d: bs=%.2x%.2x ph=%.2x ",
2009 		       t, lp->bs1, lp->bs0, lp->phase);
2010 #ifdef DBG_USE_TB
2011 		printk("tb=%10u ", lp->tb);
2012 #endif
2013 		printk(lp->fmt, lp->d);
2014 		printk("\n");
2015 		if (++i >= N_DBG_LOG)
2016 			i = 0;
2017 	} while (i != tp->log_ix);
2018 }
2019 
dumpslog(struct mesh_state * ms)2020 static void dumpslog(struct mesh_state *ms)
2021 {
2022 	struct dbglog *lp;
2023 	int i;
2024 
2025 	if (ms->n_log == 0)
2026 		return;
2027 	i = ms->log_ix - ms->n_log;
2028 	if (i < 0)
2029 		i += N_DBG_SLOG;
2030 	ms->n_log = 0;
2031 	do {
2032 		lp = &ms->log[i];
2033 		printk(KERN_DEBUG "mesh log: bs=%.2x%.2x ph=%.2x t%d ",
2034 		       lp->bs1, lp->bs0, lp->phase, lp->tgt);
2035 #ifdef DBG_USE_TB
2036 		printk("tb=%10u ", lp->tb);
2037 #endif
2038 		printk(lp->fmt, lp->d);
2039 		printk("\n");
2040 		if (++i >= N_DBG_SLOG)
2041 			i = 0;
2042 	} while (i != ms->log_ix);
2043 }
2044 #endif /* MESH_DBG */
2045 
2046 static Scsi_Host_Template driver_template = SCSI_MESH;
2047 
2048 #include "scsi_module.c"
2049