xref: /netbsd-src/sys/arch/atari/dev/atari5380.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
1 /*	$NetBSD: atari5380.c,v 1.64 2019/12/27 09:41:49 msaitoh Exp $	*/
2 
3 /*
4  * Copyright (c) 1995 Leo Weppelman.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: atari5380.c,v 1.64 2019/12/27 09:41:49 msaitoh Exp $");
30 
31 #include "opt_atariscsi.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/device.h>
37 #include <sys/buf.h>
38 #include <dev/scsipi/scsi_all.h>
39 #include <dev/scsipi/scsipi_all.h>
40 #include <dev/scsipi/scsi_message.h>
41 #include <dev/scsipi/scsiconf.h>
42 
43 #include <uvm/uvm_extern.h>
44 
45 #include <m68k/asm_single.h>
46 #include <m68k/cpu.h>
47 #include <m68k/cacheops.h>
48 
49 #include <atari/atari/stalloc.h>
50 
51 /*
52  * Include the driver definitions
53  */
54 #include <atari/dev/ncr5380reg.h>
55 
56 #include <machine/iomap.h>
57 #include <machine/mfp.h>
58 #include <machine/intr.h>
59 
60 #if defined(FALCON_SCSI)
61 #include <machine/dma.h>
62 #endif
63 
64 /*
65  * Set the various driver options
66  */
67 #define	NREQ		18	/* Size of issue queue			*/
68 #define	AUTO_SENSE	1	/* Automatically issue a request-sense 	*/
69 
70 #define	DRNAME		ncrscsi	/* used in various prints		*/
71 #undef	DBG_SEL			/* Show the selection process		*/
72 #undef	DBG_REQ			/* Show enqueued/ready requests		*/
73 #undef	DBG_ERR_RET		/* Show requests with != 0 return code	*/
74 #undef	DBG_NOWRITE		/* Do not allow writes to the targets	*/
75 #undef	DBG_PIO			/* Show the polled-I/O process		*/
76 #undef	DBG_INF			/* Show information transfer process	*/
77 #define	DBG_NOSTATIC		/* No static functions, all in DDB trace*/
78 #define	DBG_PID		15	/* Keep track of driver			*/
79 #define	REAL_DMA		/* Use DMA if sensible			*/
80 #if defined(FALCON_SCSI)
81 #define	REAL_DMA_POLL	1	/* 1: Poll for end of DMA-transfer	*/
82 #else
83 #define	REAL_DMA_POLL	0	/* 1: Poll for end of DMA-transfer	*/
84 #endif
85 #undef	USE_PDMA		/* Use special pdma-transfer function	*/
86 #define MIN_PHYS	65536	/*BARF!!!!*/
87 
88 /*
89  * Include more driver definitions
90  */
91 #include <atari/dev/ncr5380var.h>
92 
93 /*
94  * The atari specific driver options
95  */
96 #undef	NO_TTRAM_DMA		/* Do not use DMA to TT-ram. This	*/
97 				/*    fails on older atari's		*/
98 #define	ENABLE_NCR5380(sc)	cur_softc = sc;
99 
100 static uint8_t	*alloc_bounceb(u_long);
101 static void	free_bounceb(uint8_t *);
102 static int	machine_match(device_t, cfdata_t, void *, struct cfdriver *);
103 
104 void	scsi_ctrl(int);
105 void	scsi_dma(int);
106 
107 /*
108  * Functions that do nothing on the atari
109  */
110 #define	pdma_ready()		0
111 
112 #if defined(TT_SCSI)
113 
114 void	ncr5380_drq_intr(int);
115 
116 /*
117  * Define all the things we need of the DMA-controller
118  */
119 #define	SCSI_DMA	((struct scsi_dma *)AD_SCSI_DMA)
120 #define	SCSI_5380	((struct scsi_5380 *)AD_NCR5380)
121 
122 struct scsi_dma {
123 	volatile uint8_t	s_dma_ptr[8];	/* use only the odd bytes */
124 	volatile uint8_t	s_dma_cnt[8];	/* use only the odd bytes */
125 	volatile uint8_t	s_dma_res[4];	/* data residue register  */
126 	volatile uint8_t	s_dma_gap;	/* not used		  */
127 	volatile uint8_t	s_dma_ctrl;	/* control register	  */
128 	volatile uint8_t	s_dma_gap2;	/* not used		  */
129 	volatile uint8_t	s_hdma_ctrl;	/* Hades control register */
130 };
131 
132 static inline void set_scsi_dma(volatile uint8_t *, u_long);
133 static inline u_long get_scsi_dma(volatile uint8_t *);
134 
135 static inline void
136 set_scsi_dma(volatile uint8_t *addr, u_long val)
137 {
138 	volatile uint8_t *address;
139 
140 	address = addr + 1;
141 	__asm("movepl	%0, %1@(0)": :"d" (val), "a" (address));
142 }
143 
144 static inline u_long
145 get_scsi_dma(volatile uint8_t *addr)
146 {
147 	volatile uint8_t *address;
148 	u_long	nval;
149 
150 	address = addr + 1;
151 	__asm("movepl	%1@(0), %0": "=d" (nval) : "a" (address));
152 
153 	return nval;
154 }
155 
156 /*
157  * Defines for TT-DMA control register
158  */
159 #define	SD_BUSERR	0x80		/* 1 = transfer caused bus error*/
160 #define	SD_ZERO		0x40		/* 1 = byte counter is zero	*/
161 #define	SD_ENABLE	0x02		/* 1 = Enable DMA		*/
162 #define	SD_OUT		0x01		/* Direction: memory to SCSI	*/
163 #define	SD_IN		0x00		/* Direction: SCSI to memory	*/
164 
165 /*
166  * Defines for Hades-DMA control register
167  */
168 #define	SDH_BUSERR	0x02		/* 1 = Bus error		*/
169 #define SDH_EOP		0x01		/* 1 = Signal EOP on 5380	*/
170 #define	SDH_ZERO	0x40		/* 1 = Byte counter is zero	*/
171 
172 /*
173  * Define the 5380 register set
174  */
175 struct scsi_5380 {
176 	volatile uint8_t scsi_5380[16];	/* use only the odd bytes	*/
177 };
178 #endif /* TT_SCSI */
179 
180 /**********************************************
181  * Variables present for both TT and Falcon.  *
182  **********************************************/
183 
184 /*
185  * Softc of currently active controller (a bit of fake; we only have one)
186  */
187 static struct ncr_softc	*cur_softc;
188 
189 #if defined(TT_SCSI) && !defined(FALCON_SCSI)
190 /*
191  * We can be more efficient for some functions when only TT_SCSI is selected
192  */
193 #define	GET_5380_REG(rnum)	SCSI_5380->scsi_5380[(rnum << 1) | 1]
194 #define	SET_5380_REG(rnum,val)	(SCSI_5380->scsi_5380[(rnum << 1) | 1] = val)
195 
196 #define scsi_mach_init(sc)	scsi_tt_init(sc)
197 #define scsi_ienable()		scsi_tt_ienable()
198 #define scsi_idisable()		scsi_tt_idisable()
199 #define	scsi_clr_ipend()	scsi_tt_clr_ipend()
200 #define scsi_ipending()		(GET_5380_REG(NCR5380_DMSTAT) & SC_IRQ_SET)
201 #define scsi_dma_setup(r,p,m)	scsi_tt_dmasetup(r, p, m)
202 #define wrong_dma_range(r,d)	tt_wrong_dma_range(r, d)
203 #define poll_edma(reqp)		tt_poll_edma(reqp)
204 #define get_dma_result(r, b)	tt_get_dma_result(r, b)
205 #define	can_access_5380()	1
206 #define emulated_dma()		((machineid & ATARI_HADES) ? 1 : 0)
207 
208 #define fair_to_keep_dma()	1
209 #define claimed_dma()		1
210 #define reconsider_dma()
211 
212 #endif /* defined(TT_SCSI) && !defined(FALCON_SCSI) */
213 
214 #if defined(TT_SCSI)
215 
216 /*
217  * Prototype functions defined below
218  */
219 #ifdef NO_TTRAM_DMA
220 static int tt_wrong_dma_range(SC_REQ *, struct dma_chain *);
221 #endif
222 static void	scsi_tt_init(struct ncr_softc *);
223 static uint8_t	get_tt_5380_reg(u_short);
224 static void	set_tt_5380_reg(u_short, u_short);
225 static void	scsi_tt_dmasetup(SC_REQ *, u_int, uint8_t);
226 static int	tt_poll_edma(SC_REQ *);
227 static uint8_t	*ptov(SC_REQ *, u_long*);
228 static int	tt_get_dma_result(SC_REQ *, u_long *);
229 
230 void	scsi_tt_ienable(void);
231 void	scsi_tt_idisable(void);
232 void	scsi_tt_clr_ipend(void);
233 
234 /*
235  * Define these too, so we can use them locally...
236  */
237 #define	GET_TT_REG(rnum)	SCSI_5380->scsi_5380[(rnum << 1) | 1]
238 #define	SET_TT_REG(rnum,val)	(SCSI_5380->scsi_5380[(rnum << 1) | 1] = val)
239 
240 #ifdef NO_TTRAM_DMA
241 static int
242 tt_wrong_dma_range(SC_REQ *reqp, struct dma_chain *dm)
243 {
244 
245 	if (dm->dm_addr & 0xff000000) {
246 		reqp->dr_flag |= DRIVER_BOUNCING;
247 		return 1;
248 	}
249 	return 0;
250 }
251 #else
252 #define	tt_wrong_dma_range(reqp, dm)	0
253 #endif
254 
255 static void
256 scsi_tt_init(struct ncr_softc *sc)
257 {
258 
259 	/*
260 	 * Enable SCSI-related interrupts
261 	 */
262 	MFP2->mf_aer  |= 0x80;		/* SCSI IRQ goes HIGH!!!!!	*/
263 
264 	if (machineid & ATARI_TT) {
265 		/* SCSI-DMA interrupts		*/
266 		MFP2->mf_ierb |= IB_SCDM;
267 		MFP2->mf_iprb  = (uint8_t)~IB_SCDM;
268 		MFP2->mf_imrb |= IB_SCDM;
269 	} else if (machineid & ATARI_HADES) {
270 		SCSI_DMA->s_hdma_ctrl = 0;
271 
272 		if (intr_establish(2, AUTO_VEC, 0,
273 		    (hw_ifun_t)ncr5380_drq_intr, NULL) == NULL)
274 		panic("scsi_tt_init: Can't establish drq-interrupt");
275 	} else
276 		panic("scsi_tt_init: should not come here");
277 
278 	MFP2->mf_iera |= IA_SCSI;	/* SCSI-5380 interrupts		*/
279 	MFP2->mf_ipra  = (uint8_t)~IA_SCSI;
280 	MFP2->mf_imra |= IA_SCSI;
281 
282 	/*
283 	 * LWP: DMA transfers to TT-ram causes data to be garbled
284 	 * without notice on some TT-mainboard revisions.
285 	 * If programs generate mysterious Segmentations faults,
286 	 * try enabling NO_TTRAM_DMA.
287 	 */
288 #ifdef NO_TTRAM_DMA
289 	printf(": DMA to TT-RAM is disabled!");
290 #endif
291 }
292 
293 static uint8_t
294 get_tt_5380_reg(u_short rnum)
295 {
296 
297 	return SCSI_5380->scsi_5380[(rnum << 1) | 1];
298 }
299 
300 static void
301 set_tt_5380_reg(u_short rnum, u_short val)
302 {
303 
304 	SCSI_5380->scsi_5380[(rnum << 1) | 1] = val;
305 }
306 
307 static inline void
308 scsi_tt_ienable(void)
309 {
310 
311 	if (machineid & ATARI_TT)
312 		single_inst_bset_b(MFP2->mf_imrb, IB_SCDM);
313 	single_inst_bset_b(MFP2->mf_imra, IA_SCSI);
314 }
315 
316 static inline void
317 scsi_tt_idisable(void)
318 {
319 
320 	if (machineid & ATARI_TT)
321 		single_inst_bclr_b(MFP2->mf_imrb, IB_SCDM);
322 	single_inst_bclr_b(MFP2->mf_imra, IA_SCSI);
323 }
324 
325 static inline void
326 scsi_tt_clr_ipend(void)
327 {
328 	SCSI_DMA->s_dma_ctrl = 0;
329 	GET_TT_REG(NCR5380_IRCV);
330 	if (machineid & ATARI_TT)
331 		MFP2->mf_iprb = (uint8_t)~IB_SCDM;
332 	MFP2->mf_ipra = (uint8_t)~IA_SCSI;
333 
334 	/*
335 	 * Remove interrupts already scheduled.
336 	 */
337 	rem_sicallback((si_farg)ncr_ctrl_intr);
338 	rem_sicallback((si_farg)ncr_dma_intr);
339 }
340 
341 static void
342 scsi_tt_dmasetup(SC_REQ *reqp, u_int phase, uint8_t mode)
343 {
344 
345 	if (PH_IN(phase)) {
346 		SCSI_DMA->s_dma_ctrl = SD_IN;
347 		if (machineid & ATARI_HADES)
348 			SCSI_DMA->s_hdma_ctrl &= ~(SDH_BUSERR|SDH_EOP);
349 		set_scsi_dma(SCSI_DMA->s_dma_ptr, reqp->dm_cur->dm_addr);
350 		set_scsi_dma(SCSI_DMA->s_dma_cnt, reqp->dm_cur->dm_count);
351 		SET_TT_REG(NCR5380_ICOM, 0);
352 		SET_TT_REG(NCR5380_MODE, mode);
353 		SCSI_DMA->s_dma_ctrl = SD_ENABLE;
354 		SET_TT_REG(NCR5380_IRCV, 0);
355 	} else {
356 		SCSI_DMA->s_dma_ctrl = SD_OUT;
357 		if (machineid & ATARI_HADES)
358 			SCSI_DMA->s_hdma_ctrl &= ~(SDH_BUSERR|SDH_EOP);
359 		set_scsi_dma(SCSI_DMA->s_dma_ptr, reqp->dm_cur->dm_addr);
360 		set_scsi_dma(SCSI_DMA->s_dma_cnt, reqp->dm_cur->dm_count);
361 		SET_TT_REG(NCR5380_MODE, mode);
362 		SET_TT_REG(NCR5380_ICOM, SC_ADTB);
363 		SET_TT_REG(NCR5380_DMSTAT, 0);
364 		SCSI_DMA->s_dma_ctrl = SD_ENABLE|SD_OUT;
365 	}
366 }
367 
368 static int
369 tt_poll_edma(SC_REQ *reqp)
370 {
371 	uint8_t	dmstat, dmastat;
372 	int	timeout = 9000; /* XXX */
373 
374 	/*
375 	 * We wait here until the DMA has finished. This can be
376 	 * achieved by checking the following conditions:
377 	 *   - 5380:
378 	 *	- End of DMA flag is set
379 	 *	- We lost BSY (error!!)
380 	 *	- A phase mismatch has occurred (partial transfer)
381 	 *   - DMA-controller:
382 	 *	- A bus error occurred (Kernel error!!)
383 	 *	- All bytes are transferred
384 	 * If one of the terminating conditions was met, we call
385 	 * 'dma_ready' to check errors and perform the bookkeeping.
386 	 */
387 
388 	scsi_tt_idisable();
389 	for (;;) {
390 		delay(20);
391 		if (--timeout <= 0) {
392 			ncr_tprint(reqp, "timeout on polled transfer\n");
393 			reqp->xs->error = XS_TIMEOUT;
394 			scsi_tt_ienable();
395 			return 0;
396 		}
397 		dmstat  = GET_TT_REG(NCR5380_DMSTAT);
398 
399 		if ((machineid & ATARI_HADES) && (dmstat & SC_DMA_REQ)) {
400 			ncr5380_drq_intr(1);
401 			dmstat  = GET_TT_REG(NCR5380_DMSTAT);
402 		}
403 
404 		dmastat = SCSI_DMA->s_dma_ctrl;
405 		if (dmstat & (SC_END_DMA|SC_BSY_ERR|SC_IRQ_SET))
406 			break;
407 		if ((dmstat & SC_PHS_MTCH) == 0)
408 			break;
409 		if (dmastat & (SD_BUSERR|SD_ZERO))
410 			break;
411 	}
412 	scsi_tt_ienable();
413 	return 1;
414 }
415 
416 /*
417  * Convert physical DMA address to a virtual address.
418  */
419 static uint8_t *
420 ptov(SC_REQ *reqp, u_long *phaddr)
421 {
422 	struct dma_chain	*dm;
423 	uint8_t			*vaddr;
424 
425 	dm = reqp->dm_chain;
426 	vaddr = reqp->xdata_ptr;
427 	for (; dm < reqp->dm_cur; dm++)
428 		vaddr += dm->dm_count;
429 	vaddr += (u_long)phaddr - dm->dm_addr;
430 	return vaddr;
431 }
432 
433 static int
434 tt_get_dma_result(SC_REQ *reqp, u_long *bytes_left)
435 {
436 	int	dmastat, dmstat;
437 	uint8_t	*byte_p;
438 	u_long	leftover;
439 
440 	dmastat = SCSI_DMA->s_dma_ctrl;
441 	dmstat  = GET_TT_REG(NCR5380_DMSTAT);
442 	leftover = get_scsi_dma(SCSI_DMA->s_dma_cnt);
443 	byte_p = (uint8_t *)get_scsi_dma(SCSI_DMA->s_dma_ptr);
444 
445 	if (dmastat & SD_BUSERR) {
446 		/*
447 		 * The DMA-controller seems to access 8 bytes beyond
448 		 * its limits on output. Therefore check also the byte
449 		 * count. If it's zero, ignore the bus error.
450 		 */
451 		if (leftover != 0) {
452 			ncr_tprint(reqp,
453 			    "SCSI-DMA buserror - accessing 0x%x\n", byte_p);
454 			reqp->xs->error = XS_DRIVER_STUFFUP;
455 		}
456 	}
457 
458 	/*
459 	 * We handle the following special condition below:
460 	 *  -- The device disconnects in the middle of a write operation --
461 	 * In this case, the 5380 has already pre-fetched the next byte from
462 	 * the DMA-controller before the phase mismatch occurs. Therefore,
463 	 * leftover is 1 too low.
464 	 * This does not always happen! Therefore, we only do this when
465 	 * leftover is odd. This assumes that DMA transfers are _even_! This
466 	 * is normally the case on disks and types but might not always be.
467 	 * XXX: Check if ACK is consistently high on these occasions LWP
468 	 */
469 	if ((leftover & 1) &&
470 	    (dmstat & SC_PHS_MTCH) == 0 && PH_OUT(reqp->phase))
471 		leftover++;
472 
473 	/*
474 	 * Check if there are some 'restbytes' left in the DMA-controller.
475 	 */
476 	if ((machineid & ATARI_TT) &&
477 	    ((u_long)byte_p & 3) && PH_IN(reqp->phase)) {
478 		uint8_t	*p;
479 		volatile uint8_t *q;
480 
481 		p = ptov(reqp, (u_long *)((u_long)byte_p & ~3));
482 		q = SCSI_DMA->s_dma_res;
483 		switch ((u_long)byte_p & 3) {
484 			case 3: *p++ = *q++;
485 			case 2: *p++ = *q++;
486 			case 1: *p++ = *q++;
487 		}
488 	}
489 	*bytes_left = leftover;
490 	return (dmastat & (SD_BUSERR|SD_ZERO)) ? 1 : 0;
491 }
492 
493 static uint8_t *dma_ptr;
494 void
495 ncr5380_drq_intr(int poll)
496 {
497 	extern int *nofault;
498 	label_t faultbuf;
499 	int write;
500 	u_long count;
501 	volatile uint8_t *data_p = (volatile uint8_t *)(stio_addr + 0x741);
502 
503 	/*
504 	 * Block SCSI interrupts while emulating DMA. They come
505 	 * at a higher priority.
506 	 */
507 	single_inst_bclr_b(MFP2->mf_imra, IA_SCSI);
508 
509 	/*
510 	 * Setup for a possible bus error caused by SCSI controller
511 	 * switching out of DATA-IN/OUT before we're done with the
512 	 * current transfer.
513 	 */
514 	nofault = (int *)&faultbuf;
515 
516 	if (setjmp((label_t *) nofault)) {
517 		u_long cnt, tmp;
518 
519 		PID("drq berr");
520 		nofault = (int *)0;
521 
522 		/*
523 		 * Determine number of bytes transferred
524 		 */
525 		cnt = (u_long)dma_ptr - get_scsi_dma(SCSI_DMA->s_dma_ptr);
526 
527 		if (cnt != 0) {
528 			/*
529 			 * Update the DMA pointer/count fields
530 			 */
531 			set_scsi_dma(SCSI_DMA->s_dma_ptr, (u_long)dma_ptr);
532 			tmp = get_scsi_dma(SCSI_DMA->s_dma_cnt);
533 			set_scsi_dma(SCSI_DMA->s_dma_cnt, tmp - cnt);
534 
535 			if (tmp > cnt) {
536 				/*
537 				 * Still more to transfer
538 				 */
539 				if (!poll)
540 					single_inst_bset_b(MFP2->mf_imra,
541 					    IA_SCSI);
542 				return;
543 			}
544 
545 			/*
546 			 * Signal EOP to 5380
547 			 */
548 			SCSI_DMA->s_hdma_ctrl |= SDH_EOP;
549 		} else {
550 			nofault = (int *)&faultbuf;
551 
552 			/*
553 			 * Try to figure out if the byte-count was
554 			 * zero because there was no (more) data or
555 			 * because the dma_ptr is bogus.
556 			 */
557 			if (setjmp((label_t *) nofault)) {
558 				/*
559 				 * Set the bus-error bit
560 				 */
561 				SCSI_DMA->s_hdma_ctrl |= SDH_BUSERR;
562 			}
563 			__asm volatile ("tstb	%0@(0)": : "a" (dma_ptr));
564 			nofault = (int *)0;
565 		}
566 
567 		/*
568 		 * Schedule an interrupt
569 		 */
570 		if (!poll && (SCSI_DMA->s_dma_ctrl & SD_ENABLE))
571 			add_sicallback((si_farg)ncr_dma_intr,
572 			    (void *)cur_softc, 0);
573 
574 		/*
575 		 * Clear DMA-mode
576 		 */
577 		SCSI_DMA->s_dma_ctrl &= ~SD_ENABLE;
578 		if (!poll)
579 			single_inst_bset_b(MFP2->mf_imra, IA_SCSI);
580 
581 		return;
582 	}
583 
584 	write = (SCSI_DMA->s_dma_ctrl & SD_OUT) ? 1 : 0;
585 #if DBG_PID
586 	if (write) {
587 		PID("drq (in)");
588 	} else {
589 		PID("drq (out)");
590 	}
591 #endif
592 
593 	count = get_scsi_dma(SCSI_DMA->s_dma_cnt);
594 	dma_ptr = (uint8_t *)get_scsi_dma(SCSI_DMA->s_dma_ptr);
595 
596 	/*
597 	 * Keep pushing bytes until we're done or a bus-error
598 	 * signals that the SCSI controller is not ready.
599 	 * NOTE: I tried some optimalizations in these loops,
600 	 *       but they had no effect on transfer speed.
601 	 */
602 	if (write) {
603 		while (count--) {
604 			*data_p = *dma_ptr++;
605 		}
606 	} else {
607 		while (count--) {
608 			*dma_ptr++ = *data_p;
609 		}
610 	}
611 
612 	/*
613 	 * OK.  No bus error occurred above.  Clear the nofault flag
614 	 * so we no longer short-circuit bus errors.
615 	 */
616 	nofault = (int *)0;
617 
618 	/*
619 	 * Schedule an interrupt
620 	 */
621 	if (!poll && (SCSI_DMA->s_dma_ctrl & SD_ENABLE))
622 		add_sicallback((si_farg)ncr_dma_intr, (void *)cur_softc, 0);
623 
624 	/*
625 	 * Clear DMA-mode
626 	 */
627 	SCSI_DMA->s_dma_ctrl &= ~SD_ENABLE;
628 
629 	/*
630 	 * Update the DMA 'registers' to reflect that all bytes
631 	 * have been transferred and tell this to the 5380 too.
632 	 */
633 	set_scsi_dma(SCSI_DMA->s_dma_ptr, (u_long)dma_ptr);
634 	set_scsi_dma(SCSI_DMA->s_dma_cnt, 0);
635 	SCSI_DMA->s_hdma_ctrl |= SDH_EOP;
636 
637 	PID("end drq");
638 	if (!poll)
639 		single_inst_bset_b(MFP2->mf_imra, IA_SCSI);
640 
641 }
642 
643 #endif /* defined(TT_SCSI) */
644 
645 #if defined(FALCON_SCSI) && !defined(TT_SCSI)
646 
647 #define	GET_5380_REG(rnum)	get_falcon_5380_reg(rnum)
648 #define	SET_5380_REG(rnum,val)	set_falcon_5380_reg(rnum, val)
649 #define scsi_mach_init(sc)	scsi_falcon_init(sc)
650 #define scsi_ienable()		scsi_falcon_ienable()
651 #define scsi_idisable()		scsi_falcon_idisable()
652 #define	scsi_clr_ipend()	scsi_falcon_clr_ipend()
653 #define	scsi_ipending()		scsi_falcon_ipending()
654 #define scsi_dma_setup(r,p,m)	scsi_falcon_dmasetup(r, p, m)
655 #define wrong_dma_range(r,d)	falcon_wrong_dma_range(r, d)
656 #define poll_edma(reqp)		falcon_poll_edma(reqp)
657 #define get_dma_result(r, b)	falcon_get_dma_result(r, b)
658 #define	can_access_5380()	falcon_can_access_5380()
659 #define	emulated_dma()		0
660 
661 #define fair_to_keep_dma()	(!st_dmawanted())
662 #define claimed_dma()		falcon_claimed_dma()
663 #define reconsider_dma()	falcon_reconsider_dma()
664 
665 #endif /* defined(FALCON_SCSI) && !defined(TT_SCSI) */
666 
667 #if defined(FALCON_SCSI)
668 
669 /*
670  * Prototype functions defined below
671  */
672 static void	scsi_falcon_init(struct ncr_softc *);
673 static uint8_t	get_falcon_5380_reg(u_short);
674 static void	set_falcon_5380_reg(u_short, u_short);
675 static int	falcon_wrong_dma_range(SC_REQ *, struct dma_chain *);
676 static void	fal1_dma(u_int, u_int, SC_REQ *);
677 static void	scsi_falcon_dmasetup(SC_REQ  *, u_int, uint8_t);
678 static int	falcon_poll_edma(SC_REQ  *);
679 static int	falcon_get_dma_result(SC_REQ  *, u_long *);
680 
681 int	falcon_can_access_5380(void);
682 void	scsi_falcon_clr_ipend(void);
683 void	scsi_falcon_idisable(void);
684 void	scsi_falcon_ienable(void);
685 int	scsi_falcon_ipending(void);
686 int	falcon_claimed_dma(void);
687 void	falcon_reconsider_dma(void);
688 
689 static void
690 scsi_falcon_init(struct ncr_softc *sc)
691 {
692 
693 	/*
694 	 * Enable disk related interrupts
695 	 */
696 	MFP->mf_ierb  |= IB_DINT;
697 	MFP->mf_iprb   = (uint8_t)~IB_DINT;
698 	MFP->mf_imrb  |= IB_DINT;
699 }
700 
701 static uint8_t
702 get_falcon_5380_reg(u_short rnum)
703 {
704 
705 	DMA->dma_mode = DMA_SCSI + rnum;
706 	return DMA->dma_data;
707 }
708 
709 static void
710 set_falcon_5380_reg(u_short rnum, u_short val)
711 {
712 
713 	DMA->dma_mode = DMA_SCSI + rnum;
714 	DMA->dma_data = val;
715 }
716 
717 static inline void
718 scsi_falcon_ienable(void)
719 {
720 
721 	single_inst_bset_b(MFP->mf_imrb, IB_DINT);
722 }
723 
724 static inline void
725 scsi_falcon_idisable(void)
726 {
727 
728 	single_inst_bclr_b(MFP->mf_imrb, IB_DINT);
729 }
730 
731 static inline void
732 scsi_falcon_clr_ipend(void)
733 {
734 
735 	(void)get_falcon_5380_reg(NCR5380_IRCV);
736 	rem_sicallback((si_farg)ncr_ctrl_intr);
737 }
738 
739 static inline int
740 scsi_falcon_ipending(void)
741 {
742 
743 	if (connected && (connected->dr_flag & DRIVER_IN_DMA)) {
744 		/*
745 		 *  XXX: When DMA is running, we are only allowed to
746 		 *       check the 5380 when DMA _might_ be finished.
747 		 */
748 		if (MFP->mf_gpip & IO_DINT)
749 			/* XXX: Actually: we're not allowed to check */
750 			return 0;
751 
752 		/* LWP: 28-06, must be a DMA interrupt! should the
753 		 * ST-DMA unit be taken out of DMA mode?????
754 		 */
755 		DMA->dma_mode = 0x90;
756 
757 	}
758 	return get_falcon_5380_reg(NCR5380_DMSTAT) & SC_IRQ_SET;
759 }
760 
761 static int
762 falcon_wrong_dma_range(SC_REQ *reqp, struct dma_chain *dm)
763 {
764 
765 	/*
766 	 * Do not allow chains yet! See also comment with
767 	 * falcon_poll_edma() !!!
768 	 */
769 	if (((dm - reqp->dm_chain) > 0) || (dm->dm_addr & 0xff000000)) {
770 		reqp->dr_flag |= DRIVER_BOUNCING;
771 		return 1;
772 	}
773 	/*
774 	 * Never allow DMA to happen on a Falcon when the transfer
775 	 * size is no multiple of 512. This is the transfer unit of the
776 	 * ST DMA-controller.
777 	 */
778 	if (dm->dm_count & 511)
779 		return 1;
780 	return 0;
781 }
782 
783 static	int falcon_lock = 0;
784 
785 static inline int
786 falcon_claimed_dma(void)
787 {
788 
789 	if (falcon_lock != DMA_LOCK_GRANT) {
790 		if (falcon_lock == DMA_LOCK_REQ) {
791 			/*
792 			 * DMA access is being claimed.
793 			 */
794 			return 0;
795 		}
796 		if (st_dmagrab((dma_farg)ncr_ctrl_intr, (dma_farg)run_main,
797 		    cur_softc, &falcon_lock, 1, NULL) == 0)
798 			return 0;
799 	}
800 	return 1;
801 }
802 
803 static inline void
804 falcon_reconsider_dma(void)
805 {
806 
807 	if (falcon_lock && (connected == NULL) && (discon_q == NULL)) {
808 		/*
809 		 * No need to keep DMA locked by us as we are not currently
810 		 * connected and no disconnected jobs are pending.
811 		 */
812 		rem_sicallback((si_farg)ncr_ctrl_intr);
813 		st_dmafree(cur_softc, &falcon_lock);
814 	}
815 
816 	if (!falcon_lock && (issue_q != NULL)) {
817 		/*
818 		 * We must (re)claim DMA access as there are jobs
819 		 * waiting in the issue queue.
820 		 */
821 		st_dmagrab((dma_farg)ncr_ctrl_intr, (dma_farg)run_main,
822 		    cur_softc, &falcon_lock, 0, NULL);
823 	}
824 }
825 
826 static void
827 fal1_dma(u_int dir, u_int nsects, SC_REQ *reqp)
828 {
829 
830 	dir <<= 8;
831 	st_dmaaddr_set((void *)reqp->dm_cur->dm_addr);
832 	DMA->dma_mode = 0x90 | dir;
833 	DMA->dma_mode = 0x90 | (dir ^ DMA_WRBIT);
834 	DMA->dma_mode = 0x90 | dir;
835 	DMA->dma_data = nsects;
836 	delay(2);	/* _really_ needed (Thomas Gerner) */
837 	DMA->dma_mode = 0x10 | dir;
838 }
839 
840 static void
841 scsi_falcon_dmasetup(SC_REQ *reqp, u_int phase, uint8_t mode)
842 {
843 	int nsects = reqp->dm_cur->dm_count / 512; /* XXX */
844 
845 	/*
846 	 * XXX: We should probably clear the fifo before putting the
847 	 *      5380 into DMA-mode.
848 	 */
849 	if (PH_IN(phase)) {
850 		set_falcon_5380_reg(NCR5380_ICOM, 0);
851 		set_falcon_5380_reg(NCR5380_MODE, mode);
852 		set_falcon_5380_reg(NCR5380_IRCV, 0);
853 		fal1_dma(0, nsects, reqp);
854 	} else {
855 		set_falcon_5380_reg(NCR5380_MODE, mode);
856 		set_falcon_5380_reg(NCR5380_ICOM, SC_ADTB);
857 		set_falcon_5380_reg(NCR5380_DMSTAT, 0);
858 		fal1_dma(1, nsects, reqp);
859 	}
860 }
861 
862 static int
863 falcon_poll_edma(SC_REQ *reqp)
864 {
865 	int timeout = 9000; /* XXX */
866 
867 	/*
868 	 * Because of the Falcon hardware, it is impossible to reach
869 	 * the 5380 while doing DMA-transfers. So we have to rely on
870 	 * the interrupt line to determine if DMA-has finished. the
871 	 * DMA-controller itself will never fire an interrupt. This means
872 	 * that 'broken-up' DMA transfers are not (yet) possible on the
873 	 * Falcon.
874 	 */
875 	for (;;) {
876 		delay(20);
877 		if (--timeout <= 0) {
878 			ncr_tprint(reqp, "Timeout on polled transfer\n");
879 			reqp->xs->error = XS_TIMEOUT;
880 			return 0;
881 		}
882 		if ((MFP->mf_gpip & IO_DINT) == 0)
883 			break;
884 	}
885 	return 1;
886 }
887 
888 static int
889 falcon_get_dma_result(SC_REQ *reqp, u_long *bytes_left)
890 {
891 	int	rv = 0;
892 	int	st_dmastat;
893 	u_long	bytes_done;
894 
895 	/*
896 	 * Select sector counter register first (See Atari docu.)
897 	 */
898 	DMA->dma_mode = 0x90;
899 	if (!(st_dmastat = DMA->dma_stat) & 0x01) {
900 		/*
901 		 * Misc. DMA-error according to Atari...
902 		 */
903 		ncr_tprint(reqp, "Unknow ST-SCSI error near 0x%x\n",
904 		    st_dmaaddr_get());
905 		reqp->xs->error = XS_DRIVER_STUFFUP;
906 		rv = 1;
907 	}
908 	/*
909 	 * Because we NEVER start DMA on the Falcon when the data size
910 	 * is not a multiple of 512 bytes, we can safely round down the
911 	 * byte count on writes. We need to because in case of a disconnect,
912 	 * the DMA has already prefetched the next couple of bytes.
913 	 * On read, these byte counts are an error. They are logged and
914 	 * should be handled by the mi-part of the driver.
915 	 * NOTE: We formerly did this by using the 'byte-count-zero' bit
916 	 *       of the DMA controller, but this didn't seem to work???
917          *       [lwp 29/06/96]
918 	 */
919 	bytes_done = st_dmaaddr_get() - reqp->dm_cur->dm_addr;
920 	if (bytes_done & 511) {
921 		if (PH_IN(reqp->phase)) {
922 			ncr_tprint(reqp, "Byte count on read not a multiple "
923 			    "of 512 (%ld)\n", bytes_done);
924 		}
925 		bytes_done &= ~511;
926 	}
927 	if ((*bytes_left = reqp->dm_cur->dm_count - bytes_done) == 0)
928 		rv = 1;
929 	return rv;
930 }
931 
932 static int
933 falcon_can_access_5380(void)
934 {
935 
936 	if (connected && (connected->dr_flag & DRIVER_IN_DMA) &&
937 	    (MFP->mf_gpip & IO_DINT))
938 		return 0;
939 	return 1;
940 }
941 
942 #endif /* defined(FALCON_SCSI) */
943 
944 #if defined(TT_SCSI) && defined(FALCON_SCSI)
945 /*
946  * Define some functions to support _both_ TT and Falcon SCSI
947  */
948 
949 /*
950  * The prototypes first...
951  */
952 static void	scsi_mach_init(struct ncr_softc *);
953 
954 void	scsi_ienable(void);
955 void	scsi_idisable(void);
956 void	scsi_clr_ipend(void);
957 int	scsi_ipending(void);
958 void	scsi_dma_setup(SC_REQ *, u_int, uint8_t);
959 int	wrong_dma_range(SC_REQ *, struct dma_chain *);
960 int	poll_edma(SC_REQ *);
961 int	get_dma_result(SC_REQ *, u_long *);
962 int	can_access_5380(void);
963 
964 /*
965  * Register access will be done through the following 2 function pointers.
966  */
967 static uint8_t	(*get_5380_reg)(u_short);
968 static void	(*set_5380_reg)(u_short, u_short);
969 
970 #define	GET_5380_REG	(*get_5380_reg)
971 #define	SET_5380_REG	(*set_5380_reg)
972 
973 static void
974 scsi_mach_init(struct ncr_softc *sc)
975 {
976 
977 	if (machineid & ATARI_FALCON) {
978 		get_5380_reg = get_falcon_5380_reg;
979 		set_5380_reg = set_falcon_5380_reg;
980 		scsi_falcon_init(sc);
981 	} else {
982 		get_5380_reg = get_tt_5380_reg;
983 		set_5380_reg = set_tt_5380_reg;
984 		scsi_tt_init(sc);
985 	}
986 }
987 
988 static inline void
989 scsi_ienable(void)
990 {
991 
992 	if (machineid & ATARI_FALCON)
993 		scsi_falcon_ienable();
994 	else
995 		scsi_tt_ienable();
996 }
997 
998 static inline void
999 scsi_idisable(void)
1000 {
1001 
1002 	if (machineid & ATARI_FALCON)
1003 		scsi_falcon_idisable();
1004 	else
1005 		scsi_tt_idisable();
1006 }
1007 
1008 static inline void
1009 scsi_clr_ipend(void)
1010 {
1011 
1012 	if (machineid & ATARI_FALCON)
1013 		scsi_falcon_clr_ipend();
1014 	else
1015 		scsi_tt_clr_ipend();
1016 }
1017 
1018 static inline int
1019 scsi_ipending(void)
1020 {
1021 
1022 	if (machineid & ATARI_FALCON)
1023 		return scsi_falcon_ipending();
1024 	else
1025 		return GET_TT_REG(NCR5380_DMSTAT) & SC_IRQ_SET;
1026 }
1027 
1028 static inline void
1029 scsi_dma_setup(SC_REQ *reqp, u_int phase, uint8_t mbase)
1030 {
1031 
1032 	if (machineid & ATARI_FALCON)
1033 		scsi_falcon_dmasetup(reqp, phase, mbase);
1034 	else
1035 		scsi_tt_dmasetup(reqp, phase, mbase);
1036 }
1037 
1038 static inline int
1039 wrong_dma_range(SC_REQ *reqp, struct dma_chain *dm)
1040 {
1041 
1042 	if (machineid & ATARI_FALCON)
1043 		return falcon_wrong_dma_range(reqp, dm);
1044 	else
1045 		return tt_wrong_dma_range(reqp, dm);
1046 }
1047 
1048 static inline int
1049 poll_edma(SC_REQ *reqp)
1050 {
1051 
1052 	if (machineid & ATARI_FALCON)
1053 		return falcon_poll_edma(reqp);
1054 	else
1055 		return tt_poll_edma(reqp);
1056 }
1057 
1058 static inline int
1059 get_dma_result(SC_REQ *reqp, u_long *bytes_left)
1060 {
1061 
1062 	if (machineid & ATARI_FALCON)
1063 		return falcon_get_dma_result(reqp, bytes_left);
1064 	else
1065 		return tt_get_dma_result(reqp, bytes_left);
1066 }
1067 
1068 static inline int
1069 can_access_5380(void)
1070 {
1071 
1072 	if (machineid & ATARI_FALCON)
1073 		return falcon_can_access_5380();
1074 	return 1;
1075 }
1076 
1077 #define emulated_dma()		((machineid & ATARI_HADES) ? 1 : 0)
1078 
1079 /*
1080  * Locking stuff. All turns into NOP's on the TT.
1081  */
1082 #define	fair_to_keep_dma()						\
1083 	((machineid & ATARI_FALCON) ? !st_dmawanted() : 1)
1084 #define	claimed_dma()							\
1085 	((machineid & ATARI_FALCON) ? falcon_claimed_dma() : 1)
1086 #define reconsider_dma()						\
1087 	do {								\
1088 		if (machineid & ATARI_FALCON)				\
1089 			falcon_reconsider_dma();			\
1090 	} while (/* CONSTCOND */ 0)
1091 #endif /* defined(TT_SCSI) && defined(FALCON_SCSI) */
1092 
1093 /**********************************************
1094  * Functions present for both TT and Falcon.  *
1095  **********************************************/
1096 /*
1097  * Our autoconfig matching function
1098  */
1099 static int
1100 machine_match(device_t parent, cfdata_t cf, void *aux, struct cfdriver *cd)
1101 {
1102 	static int we_matched = 0; /* Only one unit	*/
1103 
1104 	if (strcmp(aux, cd->cd_name) || we_matched)
1105 		return 0;
1106 
1107 	we_matched = 1;
1108 	return 1;
1109 }
1110 
1111 /*
1112  * Bounce buffer (de)allocation. Those buffers are gotten from the ST-mem
1113  * pool. Allocation here is both contiguous and in the lower 16Mb of
1114  * the address space. Thus being DMA-able for all controllers.
1115  */
1116 static uint8_t *
1117 alloc_bounceb(u_long len)
1118 {
1119 	void *tmp;
1120 
1121 	return (uint8_t *)alloc_stmem(len, &tmp);
1122 }
1123 
1124 static void
1125 free_bounceb(uint8_t *bounceb)
1126 {
1127 
1128 	free_stmem(bounceb);
1129 }
1130 
1131 /*
1132  * 5380 interrupt.
1133  */
1134 void
1135 scsi_ctrl(int sr)
1136 {
1137 
1138 	if (GET_5380_REG(NCR5380_DMSTAT) & SC_IRQ_SET) {
1139 		scsi_idisable();
1140 		add_sicallback((si_farg)ncr_ctrl_intr, (void *)cur_softc, 0);
1141 	}
1142 }
1143 
1144 /*
1145  * DMA controller interrupt
1146  */
1147 void
1148 scsi_dma(int sr)
1149 {
1150 	SC_REQ	*reqp;
1151 
1152 	if ((reqp = connected) && (reqp->dr_flag & DRIVER_IN_DMA)) {
1153 		scsi_idisable();
1154 		add_sicallback((si_farg)ncr_dma_intr, (void *)cur_softc, 0);
1155 	}
1156 }
1157 
1158 /*
1159  * Last but not least... Include the general driver code
1160  */
1161 #include <atari/dev/ncr5380.c>
1162