xref: /freebsd/sys/dev/aic7xxx/aic7xxx_inline.h (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * Inline routines shareable across OS platforms.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 1994-2001 Justin T. Gibbs.
7  * Copyright (c) 2000-2001 Adaptec Inc.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions, and the following disclaimer,
15  *    without modification.
16  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
17  *    substantially similar to the "NO WARRANTY" disclaimer below
18  *    ("Disclaimer") and any redistribution must be conditioned upon
19  *    including a substantially similar Disclaimer requirement for further
20  *    binary redistribution.
21  * 3. Neither the names of the above-listed copyright holders nor the names
22  *    of any contributors may be used to endorse or promote products derived
23  *    from this software without specific prior written permission.
24  *
25  * Alternatively, this software may be distributed under the terms of the
26  * GNU General Public License ("GPL") version 2 as published by the Free
27  * Software Foundation.
28  *
29  * NO WARRANTY
30  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
33  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
38  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
39  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
40  * POSSIBILITY OF SUCH DAMAGES.
41  *
42  * $Id: //depot/aic7xxx/aic7xxx/aic7xxx_inline.h#47 $
43  *
44  * $FreeBSD$
45  */
46 
47 #ifndef _AIC7XXX_INLINE_H_
48 #define _AIC7XXX_INLINE_H_
49 
50 /************************* Sequencer Execution Control ************************/
51 static __inline void ahc_pause_bug_fix(struct ahc_softc *ahc);
52 static __inline int  ahc_is_paused(struct ahc_softc *ahc);
53 static __inline void ahc_pause(struct ahc_softc *ahc);
54 static __inline void ahc_unpause(struct ahc_softc *ahc);
55 
56 /*
57  * Work around any chip bugs related to halting sequencer execution.
58  * On Ultra2 controllers, we must clear the CIOBUS stretch signal by
59  * reading a register that will set this signal and deassert it.
60  * Without this workaround, if the chip is paused, by an interrupt or
61  * manual pause while accessing scb ram, accesses to certain registers
62  * will hang the system (infinite pci retries).
63  */
64 static __inline void
65 ahc_pause_bug_fix(struct ahc_softc *ahc)
66 {
67 	if ((ahc->features & AHC_ULTRA2) != 0)
68 		(void)ahc_inb(ahc, CCSCBCTL);
69 }
70 
71 /*
72  * Determine whether the sequencer has halted code execution.
73  * Returns non-zero status if the sequencer is stopped.
74  */
75 static __inline int
76 ahc_is_paused(struct ahc_softc *ahc)
77 {
78 	return ((ahc_inb(ahc, HCNTRL) & PAUSE) != 0);
79 }
80 
81 /*
82  * Request that the sequencer stop and wait, indefinitely, for it
83  * to stop.  The sequencer will only acknowledge that it is paused
84  * once it has reached an instruction boundary and PAUSEDIS is
85  * cleared in the SEQCTL register.  The sequencer may use PAUSEDIS
86  * for critical sections.
87  */
88 static __inline void
89 ahc_pause(struct ahc_softc *ahc)
90 {
91 	ahc_outb(ahc, HCNTRL, ahc->pause);
92 
93 	/*
94 	 * Since the sequencer can disable pausing in a critical section, we
95 	 * must loop until it actually stops.
96 	 */
97 	while (ahc_is_paused(ahc) == 0)
98 		;
99 
100 	ahc_pause_bug_fix(ahc);
101 }
102 
103 /*
104  * Allow the sequencer to continue program execution.
105  * We check here to ensure that no additional interrupt
106  * sources that would cause the sequencer to halt have been
107  * asserted.  If, for example, a SCSI bus reset is detected
108  * while we are fielding a different, pausing, interrupt type,
109  * we don't want to release the sequencer before going back
110  * into our interrupt handler and dealing with this new
111  * condition.
112  */
113 static __inline void
114 ahc_unpause(struct ahc_softc *ahc)
115 {
116 	if ((ahc_inb(ahc, INTSTAT) & (SCSIINT | SEQINT | BRKADRINT)) == 0)
117 		ahc_outb(ahc, HCNTRL, ahc->unpause);
118 }
119 
120 /*********************** Untagged Transaction Routines ************************/
121 static __inline void	ahc_freeze_untagged_queues(struct ahc_softc *ahc);
122 static __inline void	ahc_release_untagged_queues(struct ahc_softc *ahc);
123 
124 /*
125  * Block our completion routine from starting the next untagged
126  * transaction for this target or target lun.
127  */
128 static __inline void
129 ahc_freeze_untagged_queues(struct ahc_softc *ahc)
130 {
131 	if ((ahc->flags & AHC_SCB_BTT) == 0)
132 		ahc->untagged_queue_lock++;
133 }
134 
135 /*
136  * Allow the next untagged transaction for this target or target lun
137  * to be executed.  We use a counting semaphore to allow the lock
138  * to be acquired recursively.  Once the count drops to zero, the
139  * transaction queues will be run.
140  */
141 static __inline void
142 ahc_release_untagged_queues(struct ahc_softc *ahc)
143 {
144 	if ((ahc->flags & AHC_SCB_BTT) == 0) {
145 		ahc->untagged_queue_lock--;
146 		if (ahc->untagged_queue_lock == 0)
147 			ahc_run_untagged_queues(ahc);
148 	}
149 }
150 
151 /************************** Memory mapping routines ***************************/
152 static __inline struct ahc_dma_seg *
153 			ahc_sg_bus_to_virt(struct scb *scb,
154 					   uint32_t sg_busaddr);
155 static __inline uint32_t
156 			ahc_sg_virt_to_bus(struct scb *scb,
157 					   struct ahc_dma_seg *sg);
158 static __inline uint32_t
159 			ahc_hscb_busaddr(struct ahc_softc *ahc, u_int index);
160 static __inline void	ahc_sync_scb(struct ahc_softc *ahc,
161 				     struct scb *scb, int op);
162 static __inline void	ahc_sync_sglist(struct ahc_softc *ahc,
163 					struct scb *scb, int op);
164 static __inline uint32_t
165 			ahc_targetcmd_offset(struct ahc_softc *ahc,
166 					     u_int index);
167 
168 static __inline struct ahc_dma_seg *
169 ahc_sg_bus_to_virt(struct scb *scb, uint32_t sg_busaddr)
170 {
171 	int sg_index;
172 
173 	sg_index = (sg_busaddr - scb->sg_list_phys)/sizeof(struct ahc_dma_seg);
174 	/* sg_list_phys points to entry 1, not 0 */
175 	sg_index++;
176 
177 	return (&scb->sg_list[sg_index]);
178 }
179 
180 static __inline uint32_t
181 ahc_sg_virt_to_bus(struct scb *scb, struct ahc_dma_seg *sg)
182 {
183 	int sg_index;
184 
185 	/* sg_list_phys points to entry 1, not 0 */
186 	sg_index = sg - &scb->sg_list[1];
187 
188 	return (scb->sg_list_phys + (sg_index * sizeof(*scb->sg_list)));
189 }
190 
191 static __inline uint32_t
192 ahc_hscb_busaddr(struct ahc_softc *ahc, u_int index)
193 {
194 	return (ahc->scb_data->hscb_busaddr
195 		+ (sizeof(struct hardware_scb) * index));
196 }
197 
198 static __inline void
199 ahc_sync_scb(struct ahc_softc *ahc, struct scb *scb, int op)
200 {
201 	aic_dmamap_sync(ahc, ahc->scb_data->hscb_dmat,
202 			ahc->scb_data->hscb_dmamap,
203 			/*offset*/(scb->hscb - ahc->hscbs) * sizeof(*scb->hscb),
204 			/*len*/sizeof(*scb->hscb), op);
205 }
206 
207 static __inline void
208 ahc_sync_sglist(struct ahc_softc *ahc, struct scb *scb, int op)
209 {
210 	if (scb->sg_count == 0)
211 		return;
212 
213 	aic_dmamap_sync(ahc, ahc->scb_data->sg_dmat, scb->sg_map->sg_dmamap,
214 			/*offset*/(scb->sg_list - scb->sg_map->sg_vaddr)
215 				* sizeof(struct ahc_dma_seg),
216 			/*len*/sizeof(struct ahc_dma_seg) * scb->sg_count, op);
217 }
218 
219 static __inline uint32_t
220 ahc_targetcmd_offset(struct ahc_softc *ahc, u_int index)
221 {
222 	return (((uint8_t *)&ahc->targetcmds[index]) - ahc->qoutfifo);
223 }
224 
225 /******************************** Debugging ***********************************/
226 static __inline char *ahc_name(struct ahc_softc *ahc);
227 
228 static __inline char *
229 ahc_name(struct ahc_softc *ahc)
230 {
231 	return (ahc->name);
232 }
233 
234 /********************** Miscellaneous Support Functions ***********************/
235 
236 static __inline void	ahc_update_residual(struct ahc_softc *ahc,
237 					    struct scb *scb);
238 static __inline struct ahc_initiator_tinfo *
239 			ahc_fetch_transinfo(struct ahc_softc *ahc,
240 					    char channel, u_int our_id,
241 					    u_int remote_id,
242 					    struct ahc_tmode_tstate **tstate);
243 static __inline uint16_t
244 			ahc_inw(struct ahc_softc *ahc, u_int port);
245 static __inline void	ahc_outw(struct ahc_softc *ahc, u_int port,
246 				 u_int value);
247 static __inline uint32_t
248 			ahc_inl(struct ahc_softc *ahc, u_int port);
249 static __inline void	ahc_outl(struct ahc_softc *ahc, u_int port,
250 				 uint32_t value);
251 static __inline uint64_t
252 			ahc_inq(struct ahc_softc *ahc, u_int port);
253 static __inline void	ahc_outq(struct ahc_softc *ahc, u_int port,
254 				 uint64_t value);
255 static __inline struct scb*
256 			ahc_get_scb(struct ahc_softc *ahc);
257 static __inline void	ahc_free_scb(struct ahc_softc *ahc, struct scb *scb);
258 static __inline void	ahc_swap_with_next_hscb(struct ahc_softc *ahc,
259 						struct scb *scb);
260 static __inline void	ahc_queue_scb(struct ahc_softc *ahc, struct scb *scb);
261 static __inline struct scsi_sense_data *
262 			ahc_get_sense_buf(struct ahc_softc *ahc,
263 					  struct scb *scb);
264 static __inline uint32_t
265 			ahc_get_sense_bufaddr(struct ahc_softc *ahc,
266 					      struct scb *scb);
267 
268 /*
269  * Determine whether the sequencer reported a residual
270  * for this SCB/transaction.
271  */
272 static __inline void
273 ahc_update_residual(struct ahc_softc *ahc, struct scb *scb)
274 {
275 	uint32_t sgptr;
276 
277 	sgptr = aic_le32toh(scb->hscb->sgptr);
278 	if ((sgptr & SG_RESID_VALID) != 0)
279 		ahc_calc_residual(ahc, scb);
280 }
281 
282 /*
283  * Return pointers to the transfer negotiation information
284  * for the specified our_id/remote_id pair.
285  */
286 static __inline struct ahc_initiator_tinfo *
287 ahc_fetch_transinfo(struct ahc_softc *ahc, char channel, u_int our_id,
288 		    u_int remote_id, struct ahc_tmode_tstate **tstate)
289 {
290 	/*
291 	 * Transfer data structures are stored from the perspective
292 	 * of the target role.  Since the parameters for a connection
293 	 * in the initiator role to a given target are the same as
294 	 * when the roles are reversed, we pretend we are the target.
295 	 */
296 	if (channel == 'B')
297 		our_id += 8;
298 	*tstate = ahc->enabled_targets[our_id];
299 	return (&(*tstate)->transinfo[remote_id]);
300 }
301 
302 static __inline uint16_t
303 ahc_inw(struct ahc_softc *ahc, u_int port)
304 {
305 	return ((ahc_inb(ahc, port+1) << 8) | ahc_inb(ahc, port));
306 }
307 
308 static __inline void
309 ahc_outw(struct ahc_softc *ahc, u_int port, u_int value)
310 {
311 	ahc_outb(ahc, port, value & 0xFF);
312 	ahc_outb(ahc, port+1, (value >> 8) & 0xFF);
313 }
314 
315 static __inline uint32_t
316 ahc_inl(struct ahc_softc *ahc, u_int port)
317 {
318 	return ((ahc_inb(ahc, port))
319 	      | (ahc_inb(ahc, port+1) << 8)
320 	      | (ahc_inb(ahc, port+2) << 16)
321 	      | (ahc_inb(ahc, port+3) << 24));
322 }
323 
324 static __inline void
325 ahc_outl(struct ahc_softc *ahc, u_int port, uint32_t value)
326 {
327 	ahc_outb(ahc, port, (value) & 0xFF);
328 	ahc_outb(ahc, port+1, ((value) >> 8) & 0xFF);
329 	ahc_outb(ahc, port+2, ((value) >> 16) & 0xFF);
330 	ahc_outb(ahc, port+3, ((value) >> 24) & 0xFF);
331 }
332 
333 static __inline uint64_t
334 ahc_inq(struct ahc_softc *ahc, u_int port)
335 {
336 	return ((ahc_inb(ahc, port))
337 	      | (ahc_inb(ahc, port+1) << 8)
338 	      | (ahc_inb(ahc, port+2) << 16)
339 	      | (ahc_inb(ahc, port+3) << 24)
340 	      | (((uint64_t)ahc_inb(ahc, port+4)) << 32)
341 	      | (((uint64_t)ahc_inb(ahc, port+5)) << 40)
342 	      | (((uint64_t)ahc_inb(ahc, port+6)) << 48)
343 	      | (((uint64_t)ahc_inb(ahc, port+7)) << 56));
344 }
345 
346 static __inline void
347 ahc_outq(struct ahc_softc *ahc, u_int port, uint64_t value)
348 {
349 	ahc_outb(ahc, port, value & 0xFF);
350 	ahc_outb(ahc, port+1, (value >> 8) & 0xFF);
351 	ahc_outb(ahc, port+2, (value >> 16) & 0xFF);
352 	ahc_outb(ahc, port+3, (value >> 24) & 0xFF);
353 	ahc_outb(ahc, port+4, (value >> 32) & 0xFF);
354 	ahc_outb(ahc, port+5, (value >> 40) & 0xFF);
355 	ahc_outb(ahc, port+6, (value >> 48) & 0xFF);
356 	ahc_outb(ahc, port+7, (value >> 56) & 0xFF);
357 }
358 
359 /*
360  * Get a free scb. If there are none, see if we can allocate a new SCB.
361  */
362 static __inline struct scb *
363 ahc_get_scb(struct ahc_softc *ahc)
364 {
365 	struct scb *scb;
366 
367 	if ((scb = SLIST_FIRST(&ahc->scb_data->free_scbs)) == NULL) {
368 		if (ahc_alloc_scbs(ahc) == 0)
369 			return (NULL);
370 		scb = SLIST_FIRST(&ahc->scb_data->free_scbs);
371 		if (scb == NULL)
372 			return (NULL);
373 	}
374 	SLIST_REMOVE_HEAD(&ahc->scb_data->free_scbs, links.sle);
375 	return (scb);
376 }
377 
378 /*
379  * Return an SCB resource to the free list.
380  */
381 static __inline void
382 ahc_free_scb(struct ahc_softc *ahc, struct scb *scb)
383 {
384 	struct hardware_scb *hscb;
385 
386 	hscb = scb->hscb;
387 	/* Clean up for the next user */
388 	ahc->scb_data->scbindex[hscb->tag] = NULL;
389 	scb->flags = SCB_FLAG_NONE;
390 	hscb->control = 0;
391 
392 	SLIST_INSERT_HEAD(&ahc->scb_data->free_scbs, scb, links.sle);
393 
394 	/* Notify the OSM that a resource is now available. */
395 	aic_platform_scb_free(ahc, scb);
396 }
397 
398 static __inline struct scb *
399 ahc_lookup_scb(struct ahc_softc *ahc, u_int tag)
400 {
401 	struct scb* scb;
402 
403 	scb = ahc->scb_data->scbindex[tag];
404 	if (scb != NULL)
405 		ahc_sync_scb(ahc, scb,
406 			     BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
407 	return (scb);
408 }
409 
410 static __inline void
411 ahc_swap_with_next_hscb(struct ahc_softc *ahc, struct scb *scb)
412 {
413 	struct hardware_scb *q_hscb;
414 	u_int  saved_tag;
415 
416 	/*
417 	 * Our queuing method is a bit tricky.  The card
418 	 * knows in advance which HSCB to download, and we
419 	 * can't disappoint it.  To achieve this, the next
420 	 * SCB to download is saved off in ahc->next_queued_scb.
421 	 * When we are called to queue "an arbitrary scb",
422 	 * we copy the contents of the incoming HSCB to the one
423 	 * the sequencer knows about, swap HSCB pointers and
424 	 * finally assign the SCB to the tag indexed location
425 	 * in the scb_array.  This makes sure that we can still
426 	 * locate the correct SCB by SCB_TAG.
427 	 */
428 	q_hscb = ahc->next_queued_scb->hscb;
429 	saved_tag = q_hscb->tag;
430 	memcpy(q_hscb, scb->hscb, sizeof(*scb->hscb));
431 	if ((scb->flags & SCB_CDB32_PTR) != 0) {
432 		q_hscb->shared_data.cdb_ptr =
433 		    aic_htole32(ahc_hscb_busaddr(ahc, q_hscb->tag)
434 			      + offsetof(struct hardware_scb, cdb32));
435 	}
436 	q_hscb->tag = saved_tag;
437 	q_hscb->next = scb->hscb->tag;
438 
439 	/* Now swap HSCB pointers. */
440 	ahc->next_queued_scb->hscb = scb->hscb;
441 	scb->hscb = q_hscb;
442 
443 	/* Now define the mapping from tag to SCB in the scbindex */
444 	ahc->scb_data->scbindex[scb->hscb->tag] = scb;
445 }
446 
447 /*
448  * Tell the sequencer about a new transaction to execute.
449  */
450 static __inline void
451 ahc_queue_scb(struct ahc_softc *ahc, struct scb *scb)
452 {
453 	ahc_swap_with_next_hscb(ahc, scb);
454 
455 	if (scb->hscb->tag == SCB_LIST_NULL
456 	 || scb->hscb->next == SCB_LIST_NULL)
457 		panic("Attempt to queue invalid SCB tag %x:%x\n",
458 		      scb->hscb->tag, scb->hscb->next);
459 
460 	/*
461 	 * Setup data "oddness".
462 	 */
463 	scb->hscb->lun &= LID;
464 	if (aic_get_transfer_length(scb) & 0x1)
465 		scb->hscb->lun |= SCB_XFERLEN_ODD;
466 
467 	/*
468 	 * Keep a history of SCBs we've downloaded in the qinfifo.
469 	 */
470 	ahc->qinfifo[ahc->qinfifonext++] = scb->hscb->tag;
471 
472 	/*
473 	 * Make sure our data is consistent from the
474 	 * perspective of the adapter.
475 	 */
476 	ahc_sync_scb(ahc, scb, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
477 
478 	/* Tell the adapter about the newly queued SCB */
479 	if ((ahc->features & AHC_QUEUE_REGS) != 0) {
480 		ahc_outb(ahc, HNSCB_QOFF, ahc->qinfifonext);
481 	} else {
482 		if ((ahc->features & AHC_AUTOPAUSE) == 0)
483 			ahc_pause(ahc);
484 		ahc_outb(ahc, KERNEL_QINPOS, ahc->qinfifonext);
485 		if ((ahc->features & AHC_AUTOPAUSE) == 0)
486 			ahc_unpause(ahc);
487 	}
488 }
489 
490 static __inline struct scsi_sense_data *
491 ahc_get_sense_buf(struct ahc_softc *ahc, struct scb *scb)
492 {
493 	int offset;
494 
495 	offset = scb - ahc->scb_data->scbarray;
496 	return (&ahc->scb_data->sense[offset]);
497 }
498 
499 static __inline uint32_t
500 ahc_get_sense_bufaddr(struct ahc_softc *ahc, struct scb *scb)
501 {
502 	int offset;
503 
504 	offset = scb - ahc->scb_data->scbarray;
505 	return (ahc->scb_data->sense_busaddr
506 	      + (offset * sizeof(struct scsi_sense_data)));
507 }
508 
509 /************************** Interrupt Processing ******************************/
510 static __inline void	ahc_sync_qoutfifo(struct ahc_softc *ahc, int op);
511 static __inline void	ahc_sync_tqinfifo(struct ahc_softc *ahc, int op);
512 static __inline u_int	ahc_check_cmdcmpltqueues(struct ahc_softc *ahc);
513 static __inline int	ahc_intr(struct ahc_softc *ahc);
514 
515 static __inline void
516 ahc_sync_qoutfifo(struct ahc_softc *ahc, int op)
517 {
518 	aic_dmamap_sync(ahc, ahc->shared_data_dmat, ahc->shared_data_dmamap,
519 			/*offset*/0, /*len*/256, op);
520 }
521 
522 static __inline void
523 ahc_sync_tqinfifo(struct ahc_softc *ahc, int op)
524 {
525 #ifdef AHC_TARGET_MODE
526 	if ((ahc->flags & AHC_TARGETROLE) != 0) {
527 		aic_dmamap_sync(ahc, ahc->shared_data_dmat,
528 				ahc->shared_data_dmamap,
529 				ahc_targetcmd_offset(ahc, 0),
530 				sizeof(struct target_cmd) * AHC_TMODE_CMDS,
531 				op);
532 	}
533 #endif
534 }
535 
536 /*
537  * See if the firmware has posted any completed commands
538  * into our in-core command complete fifos.
539  */
540 #define AHC_RUN_QOUTFIFO 0x1
541 #define AHC_RUN_TQINFIFO 0x2
542 static __inline u_int
543 ahc_check_cmdcmpltqueues(struct ahc_softc *ahc)
544 {
545 	u_int retval;
546 
547 	retval = 0;
548 	aic_dmamap_sync(ahc, ahc->shared_data_dmat, ahc->shared_data_dmamap,
549 			/*offset*/ahc->qoutfifonext, /*len*/1,
550 			BUS_DMASYNC_POSTREAD);
551 	if (ahc->qoutfifo[ahc->qoutfifonext] != SCB_LIST_NULL)
552 		retval |= AHC_RUN_QOUTFIFO;
553 #ifdef AHC_TARGET_MODE
554 	if ((ahc->flags & AHC_TARGETROLE) != 0
555 	 && (ahc->flags & AHC_TQINFIFO_BLOCKED) == 0) {
556 		aic_dmamap_sync(ahc, ahc->shared_data_dmat,
557 				ahc->shared_data_dmamap,
558 				ahc_targetcmd_offset(ahc, ahc->tqinfifofnext),
559 				/*len*/sizeof(struct target_cmd),
560 				BUS_DMASYNC_POSTREAD);
561 		if (ahc->targetcmds[ahc->tqinfifonext].cmd_valid != 0)
562 			retval |= AHC_RUN_TQINFIFO;
563 	}
564 #endif
565 	return (retval);
566 }
567 
568 /*
569  * Catch an interrupt from the adapter
570  */
571 static __inline int
572 ahc_intr(struct ahc_softc *ahc)
573 {
574 	u_int	intstat;
575 
576 	if ((ahc->pause & INTEN) == 0) {
577 		/*
578 		 * Our interrupt is not enabled on the chip
579 		 * and may be disabled for re-entrancy reasons,
580 		 * so just return.  This is likely just a shared
581 		 * interrupt.
582 		 */
583 		return (0);
584 	}
585 	/*
586 	 * Instead of directly reading the interrupt status register,
587 	 * infer the cause of the interrupt by checking our in-core
588 	 * completion queues.  This avoids a costly PCI bus read in
589 	 * most cases.
590 	 */
591 	if ((ahc->flags & (AHC_ALL_INTERRUPTS|AHC_EDGE_INTERRUPT)) == 0
592 	 && (ahc_check_cmdcmpltqueues(ahc) != 0))
593 		intstat = CMDCMPLT;
594 	else {
595 		intstat = ahc_inb(ahc, INTSTAT);
596 	}
597 
598 	if ((intstat & INT_PEND) == 0) {
599 #if AIC_PCI_CONFIG > 0
600 		if (ahc->unsolicited_ints > 500) {
601 			ahc->unsolicited_ints = 0;
602 			if ((ahc->chip & AHC_PCI) != 0
603 			 && (ahc_inb(ahc, ERROR) & PCIERRSTAT) != 0)
604 				ahc->bus_intr(ahc);
605 		}
606 #endif
607 		ahc->unsolicited_ints++;
608 		return (0);
609 	}
610 	ahc->unsolicited_ints = 0;
611 
612 	if (intstat & CMDCMPLT) {
613 		ahc_outb(ahc, CLRINT, CLRCMDINT);
614 
615 		/*
616 		 * Ensure that the chip sees that we've cleared
617 		 * this interrupt before we walk the output fifo.
618 		 * Otherwise, we may, due to posted bus writes,
619 		 * clear the interrupt after we finish the scan,
620 		 * and after the sequencer has added new entries
621 		 * and asserted the interrupt again.
622 		 */
623 		ahc_flush_device_writes(ahc);
624 		ahc_run_qoutfifo(ahc);
625 #ifdef AHC_TARGET_MODE
626 		if ((ahc->flags & AHC_TARGETROLE) != 0)
627 			ahc_run_tqinfifo(ahc, /*paused*/FALSE);
628 #endif
629 	}
630 
631 	/*
632 	 * Handle statuses that may invalidate our cached
633 	 * copy of INTSTAT separately.
634 	 */
635 	if (intstat == 0xFF && (ahc->features & AHC_REMOVABLE) != 0) {
636 		/* Hot eject.  Do nothing */
637 	} else if (intstat & BRKADRINT) {
638 		ahc_handle_brkadrint(ahc);
639 	} else if ((intstat & (SEQINT|SCSIINT)) != 0) {
640 		ahc_pause_bug_fix(ahc);
641 
642 		if ((intstat & SEQINT) != 0)
643 			ahc_handle_seqint(ahc, intstat);
644 
645 		if ((intstat & SCSIINT) != 0)
646 			ahc_handle_scsiint(ahc, intstat);
647 	}
648 	return (1);
649 }
650 
651 #endif  /* _AIC7XXX_INLINE_H_ */
652