xref: /linux/drivers/s390/cio/qdio_main.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Linux for s390 qdio support, buffer handling, qdio API and module support.
4  *
5  * Copyright IBM Corp. 2000, 2008
6  * Author(s): Utz Bacher <utz.bacher@de.ibm.com>
7  *	      Jan Glauber <jang@linux.vnet.ibm.com>
8  * 2.6 cio integration by Cornelia Huck <cornelia.huck@de.ibm.com>
9  */
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/kmemleak.h>
14 #include <linux/delay.h>
15 #include <linux/gfp.h>
16 #include <linux/io.h>
17 #include <linux/atomic.h>
18 #include <asm/debug.h>
19 #include <asm/qdio.h>
20 #include <asm/asm.h>
21 #include <asm/ipl.h>
22 
23 #include "cio.h"
24 #include "css.h"
25 #include "device.h"
26 #include "qdio.h"
27 #include "qdio_debug.h"
28 
29 MODULE_AUTHOR("Utz Bacher <utz.bacher@de.ibm.com>,"\
30 	"Jan Glauber <jang@linux.vnet.ibm.com>");
31 MODULE_DESCRIPTION("QDIO base support");
32 MODULE_LICENSE("GPL");
33 
34 static inline int do_siga_sync(unsigned long schid,
35 			       unsigned long out_mask, unsigned long in_mask,
36 			       unsigned int fc)
37 {
38 	int cc;
39 
40 	asm volatile(
41 		"	lgr	0,%[fc]\n"
42 		"	lgr	1,%[schid]\n"
43 		"	lgr	2,%[out]\n"
44 		"	lgr	3,%[in]\n"
45 		"	siga	0\n"
46 		CC_IPM(cc)
47 		: CC_OUT(cc, cc)
48 		: [fc] "d" (fc), [schid] "d" (schid),
49 		  [out] "d" (out_mask), [in] "d" (in_mask)
50 		: CC_CLOBBER_LIST("0", "1", "2", "3"));
51 	return CC_TRANSFORM(cc);
52 }
53 
54 static inline int do_siga_input(unsigned long schid, unsigned long mask,
55 				unsigned long fc)
56 {
57 	int cc;
58 
59 	asm volatile(
60 		"	lgr	0,%[fc]\n"
61 		"	lgr	1,%[schid]\n"
62 		"	lgr	2,%[mask]\n"
63 		"	siga	0\n"
64 		CC_IPM(cc)
65 		: CC_OUT(cc, cc)
66 		: [fc] "d" (fc), [schid] "d" (schid), [mask] "d" (mask)
67 		: CC_CLOBBER_LIST("0", "1", "2"));
68 	return CC_TRANSFORM(cc);
69 }
70 
71 /**
72  * do_siga_output - perform SIGA-w/wt function
73  * @schid: subchannel id or in case of QEBSM the subchannel token
74  * @mask: which output queues to process
75  * @bb: busy bit indicator, set only if SIGA-w/wt could not access a buffer
76  * @fc: function code to perform
77  * @aob: asynchronous operation block
78  *
79  * Returns condition code.
80  * Note: For IQDC unicast queues only the highest priority queue is processed.
81  */
82 static inline int do_siga_output(unsigned long schid, unsigned long mask,
83 				 unsigned int *bb, unsigned long fc,
84 				 dma64_t aob)
85 {
86 	int cc;
87 
88 	asm volatile(
89 		"	lgr	0,%[fc]\n"
90 		"	lgr	1,%[schid]\n"
91 		"	lgr	2,%[mask]\n"
92 		"	lgr	3,%[aob]\n"
93 		"	siga	0\n"
94 		"	lgr	%[fc],0\n"
95 		CC_IPM(cc)
96 		: CC_OUT(cc, cc), [fc] "+&d" (fc)
97 		: [schid] "d" (schid), [mask] "d" (mask), [aob] "d" (aob)
98 		: CC_CLOBBER_LIST("0", "1", "2", "3"));
99 	*bb = fc >> 31;
100 	return CC_TRANSFORM(cc);
101 }
102 
103 /**
104  * qdio_do_eqbs - extract buffer states for QEBSM
105  * @q: queue to manipulate
106  * @state: state of the extracted buffers
107  * @start: buffer number to start at
108  * @count: count of buffers to examine
109  * @auto_ack: automatically acknowledge buffers
110  *
111  * Returns the number of successfully extracted equal buffer states.
112  * Stops processing if a state is different from the last buffers state.
113  */
114 static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
115 			int start, int count, int auto_ack)
116 {
117 	int tmp_count = count, tmp_start = start, nr = q->nr;
118 	unsigned int ccq = 0;
119 
120 	qperf_inc(q, eqbs);
121 
122 	if (!q->is_input_q)
123 		nr += q->irq_ptr->nr_input_qs;
124 again:
125 	ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count,
126 		      auto_ack);
127 
128 	switch (ccq) {
129 	case 0:
130 	case 32:
131 		/* all done, or next buffer state different */
132 		return count - tmp_count;
133 	case 96:
134 		/* not all buffers processed */
135 		qperf_inc(q, eqbs_partial);
136 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "EQBS part:%02x",
137 			tmp_count);
138 		return count - tmp_count;
139 	case 97:
140 		/* no buffer processed */
141 		DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS again:%2d", ccq);
142 		goto again;
143 	default:
144 		DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);
145 		DBF_ERROR("%4x EQBS ERROR", SCH_NO(q));
146 		DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
147 		q->handler(q->irq_ptr->cdev, QDIO_ERROR_GET_BUF_STATE, q->nr,
148 			   q->first_to_check, count, q->irq_ptr->int_parm);
149 		return 0;
150 	}
151 }
152 
153 /**
154  * qdio_do_sqbs - set buffer states for QEBSM
155  * @q: queue to manipulate
156  * @state: new state of the buffers
157  * @start: first buffer number to change
158  * @count: how many buffers to change
159  *
160  * Returns the number of successfully changed buffers.
161  * Does retrying until the specified count of buffer states is set or an
162  * error occurs.
163  */
164 static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
165 			int count)
166 {
167 	unsigned int ccq = 0;
168 	int tmp_count = count, tmp_start = start;
169 	int nr = q->nr;
170 
171 	qperf_inc(q, sqbs);
172 
173 	if (!q->is_input_q)
174 		nr += q->irq_ptr->nr_input_qs;
175 again:
176 	ccq = do_sqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
177 
178 	switch (ccq) {
179 	case 0:
180 	case 32:
181 		/* all done, or active buffer adapter-owned */
182 		WARN_ON_ONCE(tmp_count);
183 		return count - tmp_count;
184 	case 96:
185 		/* not all buffers processed */
186 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "SQBS again:%2d", ccq);
187 		qperf_inc(q, sqbs_partial);
188 		goto again;
189 	default:
190 		DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);
191 		DBF_ERROR("%4x SQBS ERROR", SCH_NO(q));
192 		DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
193 		q->handler(q->irq_ptr->cdev, QDIO_ERROR_SET_BUF_STATE, q->nr,
194 			   q->first_to_check, count, q->irq_ptr->int_parm);
195 		return 0;
196 	}
197 }
198 
199 /*
200  * Returns number of examined buffers and their common state in *state.
201  * Requested number of buffers-to-examine must be > 0.
202  */
203 static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
204 				 unsigned char *state, unsigned int count,
205 				 int auto_ack)
206 {
207 	unsigned char __state = 0;
208 	int i = 1;
209 
210 	if (is_qebsm(q))
211 		return qdio_do_eqbs(q, state, bufnr, count, auto_ack);
212 
213 	/* get initial state: */
214 	__state = q->slsb.val[bufnr];
215 
216 	/* Bail out early if there is no work on the queue: */
217 	if (__state & SLSB_OWNER_CU)
218 		goto out;
219 
220 	for (; i < count; i++) {
221 		bufnr = next_buf(bufnr);
222 
223 		/* stop if next state differs from initial state: */
224 		if (q->slsb.val[bufnr] != __state)
225 			break;
226 	}
227 
228 out:
229 	*state = __state;
230 	return i;
231 }
232 
233 static inline int get_buf_state(struct qdio_q *q, unsigned int bufnr,
234 				unsigned char *state, int auto_ack)
235 {
236 	return get_buf_states(q, bufnr, state, 1, auto_ack);
237 }
238 
239 /* wrap-around safe setting of slsb states, returns number of changed buffers */
240 static inline int set_buf_states(struct qdio_q *q, int bufnr,
241 				 unsigned char state, int count)
242 {
243 	int i;
244 
245 	if (is_qebsm(q))
246 		return qdio_do_sqbs(q, state, bufnr, count);
247 
248 	/* Ensure that all preceding changes to the SBALs are visible: */
249 	mb();
250 
251 	for (i = 0; i < count; i++) {
252 		WRITE_ONCE(q->slsb.val[bufnr], state);
253 		bufnr = next_buf(bufnr);
254 	}
255 
256 	/* Make our SLSB changes visible: */
257 	mb();
258 
259 	return count;
260 }
261 
262 static inline int set_buf_state(struct qdio_q *q, int bufnr,
263 				unsigned char state)
264 {
265 	return set_buf_states(q, bufnr, state, 1);
266 }
267 
268 /* set slsb states to initial state */
269 static void qdio_init_buf_states(struct qdio_irq *irq_ptr)
270 {
271 	struct qdio_q *q;
272 	int i;
273 
274 	for_each_input_queue(irq_ptr, q, i)
275 		set_buf_states(q, 0, SLSB_P_INPUT_NOT_INIT,
276 			       QDIO_MAX_BUFFERS_PER_Q);
277 	for_each_output_queue(irq_ptr, q, i)
278 		set_buf_states(q, 0, SLSB_P_OUTPUT_NOT_INIT,
279 			       QDIO_MAX_BUFFERS_PER_Q);
280 }
281 
282 static inline int qdio_siga_sync(struct qdio_q *q, unsigned int output,
283 			  unsigned int input)
284 {
285 	unsigned long schid = *((u32 *) &q->irq_ptr->schid);
286 	unsigned int fc = QDIO_SIGA_SYNC;
287 	int cc;
288 
289 	DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-s:%1d", q->nr);
290 	qperf_inc(q, siga_sync);
291 
292 	if (is_qebsm(q)) {
293 		schid = q->irq_ptr->sch_token;
294 		fc |= QDIO_SIGA_QEBSM_FLAG;
295 	}
296 
297 	cc = do_siga_sync(schid, output, input, fc);
298 	if (unlikely(cc))
299 		DBF_ERROR("%4x SIGA-S:%2d", SCH_NO(q), cc);
300 	return (cc) ? -EIO : 0;
301 }
302 
303 static inline int qdio_sync_input_queue(struct qdio_q *q)
304 {
305 	return qdio_siga_sync(q, 0, q->mask);
306 }
307 
308 static inline int qdio_sync_output_queue(struct qdio_q *q)
309 {
310 	return qdio_siga_sync(q, q->mask, 0);
311 }
312 
313 static inline int qdio_siga_sync_q(struct qdio_q *q)
314 {
315 	if (q->is_input_q)
316 		return qdio_sync_input_queue(q);
317 	else
318 		return qdio_sync_output_queue(q);
319 }
320 
321 static int qdio_siga_output(struct qdio_q *q, unsigned int count,
322 			    unsigned int *busy_bit, dma64_t aob)
323 {
324 	unsigned long schid = *((u32 *) &q->irq_ptr->schid);
325 	unsigned int fc = QDIO_SIGA_WRITE;
326 	u64 start_time = 0;
327 	int retries = 0, cc;
328 
329 	if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q)) {
330 		if (count > 1)
331 			fc = QDIO_SIGA_WRITEM;
332 		else if (aob)
333 			fc = QDIO_SIGA_WRITEQ;
334 	}
335 
336 	if (is_qebsm(q)) {
337 		schid = q->irq_ptr->sch_token;
338 		fc |= QDIO_SIGA_QEBSM_FLAG;
339 	}
340 again:
341 	cc = do_siga_output(schid, q->mask, busy_bit, fc, aob);
342 
343 	/* hipersocket busy condition */
344 	if (unlikely(*busy_bit)) {
345 		retries++;
346 
347 		if (!start_time) {
348 			start_time = get_tod_clock_fast();
349 			goto again;
350 		}
351 		if (get_tod_clock_fast() - start_time < QDIO_BUSY_BIT_PATIENCE)
352 			goto again;
353 	}
354 	if (retries) {
355 		DBF_DEV_EVENT(DBF_WARN, q->irq_ptr,
356 			      "%4x cc2 BB1:%1d", SCH_NO(q), q->nr);
357 		DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "count:%u", retries);
358 	}
359 	return cc;
360 }
361 
362 static inline int qdio_siga_input(struct qdio_q *q)
363 {
364 	unsigned long schid = *((u32 *) &q->irq_ptr->schid);
365 	unsigned int fc = QDIO_SIGA_READ;
366 	int cc;
367 
368 	DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-r:%1d", q->nr);
369 	qperf_inc(q, siga_read);
370 
371 	if (is_qebsm(q)) {
372 		schid = q->irq_ptr->sch_token;
373 		fc |= QDIO_SIGA_QEBSM_FLAG;
374 	}
375 
376 	cc = do_siga_input(schid, q->mask, fc);
377 	if (unlikely(cc))
378 		DBF_ERROR("%4x SIGA-R:%2d", SCH_NO(q), cc);
379 	return (cc) ? -EIO : 0;
380 }
381 
382 int debug_get_buf_state(struct qdio_q *q, unsigned int bufnr,
383 			unsigned char *state)
384 {
385 	if (qdio_need_siga_sync(q->irq_ptr))
386 		qdio_siga_sync_q(q);
387 	return get_buf_state(q, bufnr, state, 0);
388 }
389 
390 static inline void qdio_stop_polling(struct qdio_q *q)
391 {
392 	if (!q->u.in.batch_count)
393 		return;
394 
395 	qperf_inc(q, stop_polling);
396 
397 	/* show the card that we are not polling anymore */
398 	set_buf_states(q, q->u.in.batch_start, SLSB_P_INPUT_NOT_INIT,
399 		       q->u.in.batch_count);
400 	q->u.in.batch_count = 0;
401 }
402 
403 static inline void account_sbals(struct qdio_q *q, unsigned int count)
404 {
405 	q->q_stats.nr_sbal_total += count;
406 	q->q_stats.nr_sbals[ilog2(count)]++;
407 }
408 
409 static void process_buffer_error(struct qdio_q *q, unsigned int start,
410 				 int count)
411 {
412 	/* special handling for no target buffer empty */
413 	if (queue_type(q) == QDIO_IQDIO_QFMT && !q->is_input_q &&
414 	    q->sbal[start]->element[15].sflags == 0x10) {
415 		qperf_inc(q, target_full);
416 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "OUTFULL FTC:%02x", start);
417 		return;
418 	}
419 
420 	DBF_ERROR("%4x BUF ERROR", SCH_NO(q));
421 	DBF_ERROR((q->is_input_q) ? "IN:%2d" : "OUT:%2d", q->nr);
422 	DBF_ERROR("FTC:%3d C:%3d", start, count);
423 	DBF_ERROR("F14:%2x F15:%2x",
424 		  q->sbal[start]->element[14].sflags,
425 		  q->sbal[start]->element[15].sflags);
426 }
427 
428 static inline void inbound_handle_work(struct qdio_q *q, unsigned int start,
429 				       int count, bool auto_ack)
430 {
431 	/* ACK the newest SBAL: */
432 	if (!auto_ack)
433 		set_buf_state(q, add_buf(start, count - 1), SLSB_P_INPUT_ACK);
434 
435 	if (!q->u.in.batch_count)
436 		q->u.in.batch_start = start;
437 	q->u.in.batch_count += count;
438 }
439 
440 static int get_inbound_buffer_frontier(struct qdio_q *q, unsigned int start,
441 				       unsigned int *error)
442 {
443 	unsigned char state = 0;
444 	int count;
445 
446 	q->timestamp = get_tod_clock_fast();
447 
448 	count = atomic_read(&q->nr_buf_used);
449 	if (!count)
450 		return 0;
451 
452 	if (qdio_need_siga_sync(q->irq_ptr))
453 		qdio_sync_input_queue(q);
454 
455 	count = get_buf_states(q, start, &state, count, 1);
456 	if (!count)
457 		return 0;
458 
459 	switch (state) {
460 	case SLSB_P_INPUT_PRIMED:
461 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim:%1d %02x", q->nr,
462 			      count);
463 
464 		inbound_handle_work(q, start, count, is_qebsm(q));
465 		if (atomic_sub_return(count, &q->nr_buf_used) == 0)
466 			qperf_inc(q, inbound_queue_full);
467 		if (q->irq_ptr->perf_stat_enabled)
468 			account_sbals(q, count);
469 		return count;
470 	case SLSB_P_INPUT_ERROR:
471 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in err:%1d %02x", q->nr,
472 			      count);
473 
474 		*error = QDIO_ERROR_SLSB_STATE;
475 		process_buffer_error(q, start, count);
476 		inbound_handle_work(q, start, count, false);
477 		if (atomic_sub_return(count, &q->nr_buf_used) == 0)
478 			qperf_inc(q, inbound_queue_full);
479 		if (q->irq_ptr->perf_stat_enabled)
480 			account_sbals_error(q, count);
481 		return count;
482 	case SLSB_CU_INPUT_EMPTY:
483 		if (q->irq_ptr->perf_stat_enabled)
484 			q->q_stats.nr_sbal_nop++;
485 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in nop:%1d %#02x",
486 			      q->nr, start);
487 		return 0;
488 	case SLSB_P_INPUT_NOT_INIT:
489 	case SLSB_P_INPUT_ACK:
490 		/* We should never see this state, throw a WARN: */
491 	default:
492 		dev_WARN_ONCE(&q->irq_ptr->cdev->dev, 1,
493 			      "found state %#x at index %u on queue %u\n",
494 			      state, start, q->nr);
495 		return 0;
496 	}
497 }
498 
499 int qdio_inspect_input_queue(struct ccw_device *cdev, unsigned int nr,
500 			     unsigned int *bufnr, unsigned int *error)
501 {
502 	struct qdio_irq *irq = cdev->private->qdio_data;
503 	unsigned int start;
504 	struct qdio_q *q;
505 	int count;
506 
507 	if (!irq)
508 		return -ENODEV;
509 
510 	q = irq->input_qs[nr];
511 	start = q->first_to_check;
512 	*error = 0;
513 
514 	count = get_inbound_buffer_frontier(q, start, error);
515 	if (count == 0)
516 		return 0;
517 
518 	*bufnr = start;
519 	q->first_to_check = add_buf(start, count);
520 	return count;
521 }
522 EXPORT_SYMBOL_GPL(qdio_inspect_input_queue);
523 
524 static inline int qdio_inbound_q_done(struct qdio_q *q, unsigned int start)
525 {
526 	unsigned char state = 0;
527 
528 	if (!atomic_read(&q->nr_buf_used))
529 		return 1;
530 
531 	if (qdio_need_siga_sync(q->irq_ptr))
532 		qdio_sync_input_queue(q);
533 	get_buf_state(q, start, &state, 0);
534 
535 	if (state == SLSB_P_INPUT_PRIMED || state == SLSB_P_INPUT_ERROR)
536 		/* more work coming */
537 		return 0;
538 
539 	return 1;
540 }
541 
542 static int get_outbound_buffer_frontier(struct qdio_q *q, unsigned int start,
543 					unsigned int *error)
544 {
545 	unsigned char state = 0;
546 	int count;
547 
548 	q->timestamp = get_tod_clock_fast();
549 
550 	count = atomic_read(&q->nr_buf_used);
551 	if (!count)
552 		return 0;
553 
554 	if (qdio_need_siga_sync(q->irq_ptr))
555 		qdio_sync_output_queue(q);
556 
557 	count = get_buf_states(q, start, &state, count, 0);
558 	if (!count)
559 		return 0;
560 
561 	switch (state) {
562 	case SLSB_P_OUTPUT_PENDING:
563 		*error = QDIO_ERROR_SLSB_PENDING;
564 		fallthrough;
565 	case SLSB_P_OUTPUT_EMPTY:
566 		/* the adapter got it */
567 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr,
568 			"out empty:%1d %02x", q->nr, count);
569 
570 		atomic_sub(count, &q->nr_buf_used);
571 		if (q->irq_ptr->perf_stat_enabled)
572 			account_sbals(q, count);
573 		return count;
574 	case SLSB_P_OUTPUT_ERROR:
575 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out error:%1d %02x",
576 			      q->nr, count);
577 
578 		*error = QDIO_ERROR_SLSB_STATE;
579 		process_buffer_error(q, start, count);
580 		atomic_sub(count, &q->nr_buf_used);
581 		if (q->irq_ptr->perf_stat_enabled)
582 			account_sbals_error(q, count);
583 		return count;
584 	case SLSB_CU_OUTPUT_PRIMED:
585 		/* the adapter has not fetched the output yet */
586 		if (q->irq_ptr->perf_stat_enabled)
587 			q->q_stats.nr_sbal_nop++;
588 		DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out primed:%1d",
589 			      q->nr);
590 		return 0;
591 	case SLSB_P_OUTPUT_HALTED:
592 		return 0;
593 	case SLSB_P_OUTPUT_NOT_INIT:
594 		/* We should never see this state, throw a WARN: */
595 	default:
596 		dev_WARN_ONCE(&q->irq_ptr->cdev->dev, 1,
597 			      "found state %#x at index %u on queue %u\n",
598 			      state, start, q->nr);
599 		return 0;
600 	}
601 }
602 
603 int qdio_inspect_output_queue(struct ccw_device *cdev, unsigned int nr,
604 			      unsigned int *bufnr, unsigned int *error)
605 {
606 	struct qdio_irq *irq = cdev->private->qdio_data;
607 	unsigned int start;
608 	struct qdio_q *q;
609 	int count;
610 
611 	if (!irq)
612 		return -ENODEV;
613 
614 	q = irq->output_qs[nr];
615 	start = q->first_to_check;
616 	*error = 0;
617 
618 	count = get_outbound_buffer_frontier(q, start, error);
619 	if (count == 0)
620 		return 0;
621 
622 	*bufnr = start;
623 	q->first_to_check = add_buf(start, count);
624 	return count;
625 }
626 EXPORT_SYMBOL_GPL(qdio_inspect_output_queue);
627 
628 static int qdio_kick_outbound_q(struct qdio_q *q, unsigned int count,
629 				dma64_t aob)
630 {
631 	int retries = 0, cc;
632 	unsigned int busy_bit;
633 
634 	if (!qdio_need_siga_out(q->irq_ptr))
635 		return 0;
636 
637 	DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-w:%1d", q->nr);
638 retry:
639 	qperf_inc(q, siga_write);
640 
641 	cc = qdio_siga_output(q, count, &busy_bit, aob);
642 	switch (cc) {
643 	case 0:
644 		break;
645 	case 2:
646 		if (busy_bit) {
647 			while (++retries < QDIO_BUSY_BIT_RETRIES) {
648 				mdelay(QDIO_BUSY_BIT_RETRY_DELAY);
649 				goto retry;
650 			}
651 			DBF_ERROR("%4x cc2 BBC:%1d", SCH_NO(q), q->nr);
652 			cc = -EBUSY;
653 		} else {
654 			DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-w cc2:%1d", q->nr);
655 			cc = -ENOBUFS;
656 		}
657 		break;
658 	case 1:
659 	case 3:
660 		DBF_ERROR("%4x SIGA-W:%1d", SCH_NO(q), cc);
661 		cc = -EIO;
662 		break;
663 	}
664 	if (retries) {
665 		DBF_ERROR("%4x cc2 BB2:%1d", SCH_NO(q), q->nr);
666 		DBF_ERROR("count:%u", retries);
667 	}
668 	return cc;
669 }
670 
671 static inline void qdio_set_state(struct qdio_irq *irq_ptr,
672 				  enum qdio_irq_states state)
673 {
674 	DBF_DEV_EVENT(DBF_INFO, irq_ptr, "newstate: %1d", state);
675 
676 	irq_ptr->state = state;
677 	mb();
678 }
679 
680 static void qdio_irq_check_sense(struct qdio_irq *irq_ptr, struct irb *irb)
681 {
682 	if (irb->esw.esw0.erw.cons) {
683 		DBF_ERROR("%4x sense:", irq_ptr->schid.sch_no);
684 		DBF_ERROR_HEX(irb, 64);
685 		DBF_ERROR_HEX(irb->ecw, 64);
686 	}
687 }
688 
689 /* PCI interrupt handler */
690 static void qdio_int_handler_pci(struct qdio_irq *irq_ptr)
691 {
692 	if (unlikely(irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
693 		return;
694 
695 	qdio_deliver_irq(irq_ptr);
696 	irq_ptr->last_data_irq_time = get_lowcore()->int_clock;
697 }
698 
699 static void qdio_handle_activate_check(struct qdio_irq *irq_ptr,
700 				       unsigned long intparm, int cstat,
701 				       int dstat)
702 {
703 	unsigned int first_to_check = 0;
704 
705 	DBF_ERROR("%4x ACT CHECK", irq_ptr->schid.sch_no);
706 	DBF_ERROR("intp :%lx", intparm);
707 	DBF_ERROR("ds: %2x cs:%2x", dstat, cstat);
708 
709 	/* zfcp wants this: */
710 	if (irq_ptr->nr_input_qs)
711 		first_to_check = irq_ptr->input_qs[0]->first_to_check;
712 
713 	irq_ptr->error_handler(irq_ptr->cdev, QDIO_ERROR_ACTIVATE, 0,
714 			       first_to_check, 0, irq_ptr->int_parm);
715 	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
716 	/*
717 	 * In case of z/VM LGR (Live Guest Migration) QDIO recovery will happen.
718 	 * Therefore we call the LGR detection function here.
719 	 */
720 	lgr_info_log();
721 }
722 
723 static int qdio_establish_handle_irq(struct qdio_irq *irq_ptr, int cstat,
724 				     int dstat, int dcc)
725 {
726 	DBF_DEV_EVENT(DBF_INFO, irq_ptr, "qest irq");
727 
728 	if (cstat)
729 		goto error;
730 	if (dstat & ~(DEV_STAT_DEV_END | DEV_STAT_CHN_END))
731 		goto error;
732 	if (dcc == 1)
733 		return -EAGAIN;
734 	if (!(dstat & DEV_STAT_DEV_END))
735 		goto error;
736 	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ESTABLISHED);
737 	return 0;
738 
739 error:
740 	DBF_ERROR("%4x EQ:error", irq_ptr->schid.sch_no);
741 	DBF_ERROR("ds: %2x cs:%2x", dstat, cstat);
742 	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);
743 	return -EIO;
744 }
745 
746 /* qdio interrupt handler */
747 void qdio_int_handler(struct ccw_device *cdev, unsigned long intparm,
748 		      struct irb *irb)
749 {
750 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
751 	struct subchannel_id schid;
752 	int cstat, dstat, rc, dcc;
753 
754 	if (!intparm || !irq_ptr) {
755 		ccw_device_get_schid(cdev, &schid);
756 		DBF_ERROR("qint:%4x", schid.sch_no);
757 		return;
758 	}
759 
760 	if (irq_ptr->perf_stat_enabled)
761 		irq_ptr->perf_stat.qdio_int++;
762 
763 	if (IS_ERR(irb)) {
764 		DBF_ERROR("%4x IO error", irq_ptr->schid.sch_no);
765 		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);
766 		wake_up(&cdev->private->wait_q);
767 		return;
768 	}
769 	qdio_irq_check_sense(irq_ptr, irb);
770 	cstat = irb->scsw.cmd.cstat;
771 	dstat = irb->scsw.cmd.dstat;
772 	dcc   = scsw_cmd_is_valid_cc(&irb->scsw) ? irb->scsw.cmd.cc : 0;
773 	rc    = 0;
774 
775 	switch (irq_ptr->state) {
776 	case QDIO_IRQ_STATE_INACTIVE:
777 		rc = qdio_establish_handle_irq(irq_ptr, cstat, dstat, dcc);
778 		break;
779 	case QDIO_IRQ_STATE_CLEANUP:
780 		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
781 		break;
782 	case QDIO_IRQ_STATE_ESTABLISHED:
783 	case QDIO_IRQ_STATE_ACTIVE:
784 		if (cstat & SCHN_STAT_PCI) {
785 			qdio_int_handler_pci(irq_ptr);
786 			return;
787 		}
788 		if (cstat || dstat)
789 			qdio_handle_activate_check(irq_ptr, intparm, cstat,
790 						   dstat);
791 		else if (dcc == 1)
792 			rc = -EAGAIN;
793 		break;
794 	case QDIO_IRQ_STATE_STOPPED:
795 		break;
796 	default:
797 		WARN_ON_ONCE(1);
798 	}
799 
800 	if (rc == -EAGAIN) {
801 		DBF_DEV_EVENT(DBF_INFO, irq_ptr, "qint retry");
802 		rc = ccw_device_start(cdev, irq_ptr->ccw, intparm, 0, 0);
803 		if (!rc)
804 			return;
805 		DBF_ERROR("%4x RETRY ERR", irq_ptr->schid.sch_no);
806 		DBF_ERROR("rc:%4x", rc);
807 		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);
808 	}
809 
810 	wake_up(&cdev->private->wait_q);
811 }
812 
813 /**
814  * qdio_get_ssqd_desc - get qdio subchannel description
815  * @cdev: ccw device to get description for
816  * @data: where to store the ssqd
817  *
818  * Returns 0 or an error code. The results of the chsc are stored in the
819  * specified structure.
820  */
821 int qdio_get_ssqd_desc(struct ccw_device *cdev,
822 		       struct qdio_ssqd_desc *data)
823 {
824 	struct subchannel_id schid;
825 
826 	if (!cdev || !cdev->private)
827 		return -EINVAL;
828 
829 	ccw_device_get_schid(cdev, &schid);
830 	DBF_EVENT("get ssqd:%4x", schid.sch_no);
831 	return qdio_setup_get_ssqd(NULL, &schid, data);
832 }
833 EXPORT_SYMBOL_GPL(qdio_get_ssqd_desc);
834 
835 static int qdio_cancel_ccw(struct qdio_irq *irq, int how)
836 {
837 	struct ccw_device *cdev = irq->cdev;
838 	long timeout;
839 	int rc;
840 
841 	spin_lock_irq(get_ccwdev_lock(cdev));
842 	qdio_set_state(irq, QDIO_IRQ_STATE_CLEANUP);
843 	if (how & QDIO_FLAG_CLEANUP_USING_CLEAR)
844 		rc = ccw_device_clear(cdev, QDIO_DOING_CLEANUP);
845 	else
846 		/* default behaviour is halt */
847 		rc = ccw_device_halt(cdev, QDIO_DOING_CLEANUP);
848 	spin_unlock_irq(get_ccwdev_lock(cdev));
849 	if (rc) {
850 		DBF_ERROR("%4x SHUTD ERR", irq->schid.sch_no);
851 		DBF_ERROR("rc:%4d", rc);
852 		return rc;
853 	}
854 
855 	timeout = wait_event_interruptible_timeout(cdev->private->wait_q,
856 						   irq->state == QDIO_IRQ_STATE_INACTIVE ||
857 						   irq->state == QDIO_IRQ_STATE_ERR,
858 						   10 * HZ);
859 	if (timeout <= 0)
860 		rc = (timeout == -ERESTARTSYS) ? -EINTR : -ETIME;
861 
862 	return rc;
863 }
864 
865 /**
866  * qdio_shutdown - shut down a qdio subchannel
867  * @cdev: associated ccw device
868  * @how: use halt or clear to shutdown
869  */
870 int qdio_shutdown(struct ccw_device *cdev, int how)
871 {
872 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
873 	struct subchannel_id schid;
874 	int rc;
875 
876 	if (!irq_ptr)
877 		return -ENODEV;
878 
879 	WARN_ON_ONCE(irqs_disabled());
880 	ccw_device_get_schid(cdev, &schid);
881 	DBF_EVENT("qshutdown:%4x", schid.sch_no);
882 
883 	mutex_lock(&irq_ptr->setup_mutex);
884 	/*
885 	 * Subchannel was already shot down. We cannot prevent being called
886 	 * twice since cio may trigger a shutdown asynchronously.
887 	 */
888 	if (irq_ptr->state == QDIO_IRQ_STATE_INACTIVE) {
889 		mutex_unlock(&irq_ptr->setup_mutex);
890 		return 0;
891 	}
892 
893 	/*
894 	 * Indicate that the device is going down.
895 	 */
896 	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
897 
898 	qdio_shutdown_debug_entries(irq_ptr);
899 
900 	rc = qdio_cancel_ccw(irq_ptr, how);
901 	qdio_shutdown_thinint(irq_ptr);
902 	qdio_shutdown_irq(irq_ptr);
903 
904 	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
905 	mutex_unlock(&irq_ptr->setup_mutex);
906 	if (rc)
907 		return rc;
908 	return 0;
909 }
910 EXPORT_SYMBOL_GPL(qdio_shutdown);
911 
912 /**
913  * qdio_free - free data structures for a qdio subchannel
914  * @cdev: associated ccw device
915  */
916 int qdio_free(struct ccw_device *cdev)
917 {
918 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
919 	struct subchannel_id schid;
920 
921 	if (!irq_ptr)
922 		return -ENODEV;
923 
924 	ccw_device_get_schid(cdev, &schid);
925 	DBF_EVENT("qfree:%4x", schid.sch_no);
926 	DBF_DEV_EVENT(DBF_ERR, irq_ptr, "dbf abandoned");
927 	mutex_lock(&irq_ptr->setup_mutex);
928 
929 	irq_ptr->debug_area = NULL;
930 	cdev->private->qdio_data = NULL;
931 	mutex_unlock(&irq_ptr->setup_mutex);
932 
933 	qdio_free_queues(irq_ptr);
934 	free_page((unsigned long) irq_ptr->qdr);
935 	free_page(irq_ptr->chsc_page);
936 	kfree(irq_ptr->ccw);
937 	free_page((unsigned long) irq_ptr);
938 	return 0;
939 }
940 EXPORT_SYMBOL_GPL(qdio_free);
941 
942 /**
943  * qdio_allocate - allocate qdio queues and associated data
944  * @cdev: associated ccw device
945  * @no_input_qs: allocate this number of Input Queues
946  * @no_output_qs: allocate this number of Output Queues
947  */
948 int qdio_allocate(struct ccw_device *cdev, unsigned int no_input_qs,
949 		  unsigned int no_output_qs)
950 {
951 	struct subchannel_id schid;
952 	struct qdio_irq *irq_ptr;
953 	int rc = -ENOMEM;
954 
955 	ccw_device_get_schid(cdev, &schid);
956 	DBF_EVENT("qallocate:%4x", schid.sch_no);
957 
958 	if (no_input_qs > QDIO_MAX_QUEUES_PER_IRQ ||
959 	    no_output_qs > QDIO_MAX_QUEUES_PER_IRQ)
960 		return -EINVAL;
961 
962 	irq_ptr = (void *) get_zeroed_page(GFP_KERNEL);
963 	if (!irq_ptr)
964 		return -ENOMEM;
965 
966 	irq_ptr->ccw = kmalloc(sizeof(*irq_ptr->ccw), GFP_KERNEL | GFP_DMA);
967 	if (!irq_ptr->ccw)
968 		goto err_ccw;
969 
970 	/* kmemleak doesn't scan the page-allocated irq_ptr: */
971 	kmemleak_not_leak(irq_ptr->ccw);
972 
973 	irq_ptr->cdev = cdev;
974 	mutex_init(&irq_ptr->setup_mutex);
975 	if (qdio_allocate_dbf(irq_ptr))
976 		goto err_dbf;
977 
978 	DBF_DEV_EVENT(DBF_ERR, irq_ptr, "alloc niq:%1u noq:%1u", no_input_qs,
979 		      no_output_qs);
980 
981 	/*
982 	 * Allocate a page for the chsc calls in qdio_establish.
983 	 * Must be pre-allocated since a zfcp recovery will call
984 	 * qdio_establish. In case of low memory and swap on a zfcp disk
985 	 * we may not be able to allocate memory otherwise.
986 	 */
987 	irq_ptr->chsc_page = get_zeroed_page(GFP_KERNEL);
988 	if (!irq_ptr->chsc_page)
989 		goto err_chsc;
990 
991 	/* qdr is used in ccw1.cda which is u32 */
992 	irq_ptr->qdr = (struct qdr *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
993 	if (!irq_ptr->qdr)
994 		goto err_qdr;
995 
996 	rc = qdio_allocate_qs(irq_ptr, no_input_qs, no_output_qs);
997 	if (rc)
998 		goto err_queues;
999 
1000 	cdev->private->qdio_data = irq_ptr;
1001 	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
1002 	return 0;
1003 
1004 err_queues:
1005 	free_page((unsigned long) irq_ptr->qdr);
1006 err_qdr:
1007 	free_page(irq_ptr->chsc_page);
1008 err_chsc:
1009 err_dbf:
1010 	kfree(irq_ptr->ccw);
1011 err_ccw:
1012 	free_page((unsigned long) irq_ptr);
1013 	return rc;
1014 }
1015 EXPORT_SYMBOL_GPL(qdio_allocate);
1016 
1017 static void qdio_trace_init_data(struct qdio_irq *irq,
1018 				 struct qdio_initialize *data)
1019 {
1020 	DBF_DEV_EVENT(DBF_ERR, irq, "qfmt:%1u", data->q_format);
1021 	DBF_DEV_EVENT(DBF_ERR, irq, "qpff%4x", data->qib_param_field_format);
1022 	DBF_DEV_HEX(irq, &data->qib_param_field, sizeof(void *), DBF_ERR);
1023 	DBF_DEV_EVENT(DBF_ERR, irq, "niq:%1u noq:%1u", data->no_input_qs,
1024 		      data->no_output_qs);
1025 	DBF_DEV_HEX(irq, &data->input_handler, sizeof(void *), DBF_ERR);
1026 	DBF_DEV_HEX(irq, &data->output_handler, sizeof(void *), DBF_ERR);
1027 	DBF_DEV_HEX(irq, &data->int_parm, sizeof(long), DBF_ERR);
1028 	DBF_DEV_HEX(irq, &data->input_sbal_addr_array, sizeof(void *), DBF_ERR);
1029 	DBF_DEV_HEX(irq, &data->output_sbal_addr_array, sizeof(void *),
1030 		    DBF_ERR);
1031 }
1032 
1033 /**
1034  * qdio_establish - establish queues on a qdio subchannel
1035  * @cdev: associated ccw device
1036  * @init_data: initialization data
1037  */
1038 int qdio_establish(struct ccw_device *cdev,
1039 		   struct qdio_initialize *init_data)
1040 {
1041 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
1042 	struct subchannel_id schid;
1043 	struct ciw *ciw;
1044 	long timeout;
1045 	int rc;
1046 
1047 	ccw_device_get_schid(cdev, &schid);
1048 	DBF_EVENT("qestablish:%4x", schid.sch_no);
1049 
1050 	if (!irq_ptr)
1051 		return -ENODEV;
1052 
1053 	if (init_data->no_input_qs > irq_ptr->max_input_qs ||
1054 	    init_data->no_output_qs > irq_ptr->max_output_qs)
1055 		return -EINVAL;
1056 
1057 	/* Needed as error_handler: */
1058 	if (!init_data->input_handler)
1059 		return -EINVAL;
1060 
1061 	if (init_data->no_output_qs && !init_data->output_handler)
1062 		return -EINVAL;
1063 
1064 	if (!init_data->input_sbal_addr_array ||
1065 	    !init_data->output_sbal_addr_array)
1066 		return -EINVAL;
1067 
1068 	if (!init_data->irq_poll)
1069 		return -EINVAL;
1070 
1071 	ciw = ccw_device_get_ciw(cdev, CIW_TYPE_EQUEUE);
1072 	if (!ciw) {
1073 		DBF_ERROR("%4x NO EQ", schid.sch_no);
1074 		return -EIO;
1075 	}
1076 
1077 	mutex_lock(&irq_ptr->setup_mutex);
1078 	qdio_trace_init_data(irq_ptr, init_data);
1079 	qdio_setup_irq(irq_ptr, init_data);
1080 
1081 	rc = qdio_establish_thinint(irq_ptr);
1082 	if (rc)
1083 		goto err_thinint;
1084 
1085 	/* establish q */
1086 	irq_ptr->ccw->cmd_code = ciw->cmd;
1087 	irq_ptr->ccw->flags = CCW_FLAG_SLI;
1088 	irq_ptr->ccw->count = ciw->count;
1089 	irq_ptr->ccw->cda = virt_to_dma32(irq_ptr->qdr);
1090 
1091 	spin_lock_irq(get_ccwdev_lock(cdev));
1092 	ccw_device_set_options_mask(cdev, 0);
1093 
1094 	rc = ccw_device_start(cdev, irq_ptr->ccw, QDIO_DOING_ESTABLISH, 0, 0);
1095 	spin_unlock_irq(get_ccwdev_lock(cdev));
1096 	if (rc) {
1097 		DBF_ERROR("%4x est IO ERR", irq_ptr->schid.sch_no);
1098 		DBF_ERROR("rc:%4x", rc);
1099 		goto err_ccw_start;
1100 	}
1101 
1102 	timeout = wait_event_interruptible_timeout(cdev->private->wait_q,
1103 						   irq_ptr->state == QDIO_IRQ_STATE_ESTABLISHED ||
1104 						   irq_ptr->state == QDIO_IRQ_STATE_ERR, HZ);
1105 	if (timeout <= 0) {
1106 		rc = (timeout == -ERESTARTSYS) ? -EINTR : -ETIME;
1107 		goto err_ccw_timeout;
1108 	}
1109 
1110 	if (irq_ptr->state != QDIO_IRQ_STATE_ESTABLISHED) {
1111 		rc = -EIO;
1112 		goto err_ccw_error;
1113 	}
1114 
1115 	qdio_setup_ssqd_info(irq_ptr);
1116 
1117 	/* qebsm is now setup if available, initialize buffer states */
1118 	qdio_init_buf_states(irq_ptr);
1119 
1120 	mutex_unlock(&irq_ptr->setup_mutex);
1121 	qdio_print_subchannel_info(irq_ptr);
1122 	qdio_setup_debug_entries(irq_ptr);
1123 	return 0;
1124 
1125 err_ccw_timeout:
1126 	qdio_cancel_ccw(irq_ptr, QDIO_FLAG_CLEANUP_USING_CLEAR);
1127 err_ccw_error:
1128 err_ccw_start:
1129 	qdio_shutdown_thinint(irq_ptr);
1130 err_thinint:
1131 	qdio_shutdown_irq(irq_ptr);
1132 	qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
1133 	mutex_unlock(&irq_ptr->setup_mutex);
1134 	return rc;
1135 }
1136 EXPORT_SYMBOL_GPL(qdio_establish);
1137 
1138 /**
1139  * qdio_activate - activate queues on a qdio subchannel
1140  * @cdev: associated cdev
1141  */
1142 int qdio_activate(struct ccw_device *cdev)
1143 {
1144 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
1145 	struct subchannel_id schid;
1146 	struct ciw *ciw;
1147 	int rc;
1148 
1149 	ccw_device_get_schid(cdev, &schid);
1150 	DBF_EVENT("qactivate:%4x", schid.sch_no);
1151 
1152 	if (!irq_ptr)
1153 		return -ENODEV;
1154 
1155 	ciw = ccw_device_get_ciw(cdev, CIW_TYPE_AQUEUE);
1156 	if (!ciw) {
1157 		DBF_ERROR("%4x NO AQ", schid.sch_no);
1158 		return -EIO;
1159 	}
1160 
1161 	mutex_lock(&irq_ptr->setup_mutex);
1162 	if (irq_ptr->state == QDIO_IRQ_STATE_INACTIVE) {
1163 		rc = -EBUSY;
1164 		goto out;
1165 	}
1166 
1167 	irq_ptr->ccw->cmd_code = ciw->cmd;
1168 	irq_ptr->ccw->flags = CCW_FLAG_SLI;
1169 	irq_ptr->ccw->count = ciw->count;
1170 	irq_ptr->ccw->cda = 0;
1171 
1172 	spin_lock_irq(get_ccwdev_lock(cdev));
1173 	ccw_device_set_options(cdev, CCWDEV_REPORT_ALL);
1174 
1175 	rc = ccw_device_start(cdev, irq_ptr->ccw, QDIO_DOING_ACTIVATE,
1176 			      0, DOIO_DENY_PREFETCH);
1177 	spin_unlock_irq(get_ccwdev_lock(cdev));
1178 	if (rc) {
1179 		DBF_ERROR("%4x act IO ERR", irq_ptr->schid.sch_no);
1180 		DBF_ERROR("rc:%4x", rc);
1181 		goto out;
1182 	}
1183 
1184 	/* wait for subchannel to become active */
1185 	msleep(5);
1186 
1187 	switch (irq_ptr->state) {
1188 	case QDIO_IRQ_STATE_STOPPED:
1189 	case QDIO_IRQ_STATE_ERR:
1190 		rc = -EIO;
1191 		break;
1192 	default:
1193 		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ACTIVE);
1194 		rc = 0;
1195 	}
1196 out:
1197 	mutex_unlock(&irq_ptr->setup_mutex);
1198 	return rc;
1199 }
1200 EXPORT_SYMBOL_GPL(qdio_activate);
1201 
1202 /**
1203  * handle_inbound - reset processed input buffers
1204  * @q: queue containing the buffers
1205  * @bufnr: first buffer to process
1206  * @count: how many buffers are emptied
1207  */
1208 static int handle_inbound(struct qdio_q *q, int bufnr, int count)
1209 {
1210 	int overlap;
1211 
1212 	qperf_inc(q, inbound_call);
1213 
1214 	/* If any processed SBALs are returned to HW, adjust our tracking: */
1215 	overlap = min_t(int, count - sub_buf(q->u.in.batch_start, bufnr),
1216 			     q->u.in.batch_count);
1217 	if (overlap > 0) {
1218 		q->u.in.batch_start = add_buf(q->u.in.batch_start, overlap);
1219 		q->u.in.batch_count -= overlap;
1220 	}
1221 
1222 	count = set_buf_states(q, bufnr, SLSB_CU_INPUT_EMPTY, count);
1223 	atomic_add(count, &q->nr_buf_used);
1224 
1225 	if (qdio_need_siga_in(q->irq_ptr))
1226 		return qdio_siga_input(q);
1227 
1228 	return 0;
1229 }
1230 
1231 /**
1232  * qdio_add_bufs_to_input_queue - process buffers on an Input Queue
1233  * @cdev: associated ccw_device for the qdio subchannel
1234  * @q_nr: queue number
1235  * @bufnr: buffer number
1236  * @count: how many buffers to process
1237  */
1238 int qdio_add_bufs_to_input_queue(struct ccw_device *cdev, unsigned int q_nr,
1239 				 unsigned int bufnr, unsigned int count)
1240 {
1241 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
1242 
1243 	if (bufnr >= QDIO_MAX_BUFFERS_PER_Q || count > QDIO_MAX_BUFFERS_PER_Q)
1244 		return -EINVAL;
1245 
1246 	if (!irq_ptr)
1247 		return -ENODEV;
1248 
1249 	DBF_DEV_EVENT(DBF_INFO, irq_ptr, "addi b:%02x c:%02x", bufnr, count);
1250 
1251 	if (irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)
1252 		return -EIO;
1253 	if (!count)
1254 		return 0;
1255 
1256 	return handle_inbound(irq_ptr->input_qs[q_nr], bufnr, count);
1257 }
1258 EXPORT_SYMBOL_GPL(qdio_add_bufs_to_input_queue);
1259 
1260 /**
1261  * handle_outbound - process filled outbound buffers
1262  * @q: queue containing the buffers
1263  * @bufnr: first buffer to process
1264  * @count: how many buffers are filled
1265  * @aob: asynchronous operation block
1266  */
1267 static int handle_outbound(struct qdio_q *q, unsigned int bufnr, unsigned int count,
1268 			   struct qaob *aob)
1269 {
1270 	unsigned char state = 0;
1271 	int used, rc = 0;
1272 
1273 	qperf_inc(q, outbound_call);
1274 
1275 	count = set_buf_states(q, bufnr, SLSB_CU_OUTPUT_PRIMED, count);
1276 	used = atomic_add_return(count, &q->nr_buf_used);
1277 
1278 	if (used == QDIO_MAX_BUFFERS_PER_Q)
1279 		qperf_inc(q, outbound_queue_full);
1280 
1281 	if (queue_type(q) == QDIO_IQDIO_QFMT) {
1282 		dma64_t phys_aob = aob ? virt_to_dma64(aob) : 0;
1283 
1284 		WARN_ON_ONCE(!IS_ALIGNED(dma64_to_u64(phys_aob), 256));
1285 		rc = qdio_kick_outbound_q(q, count, phys_aob);
1286 	} else if (qdio_need_siga_sync(q->irq_ptr)) {
1287 		rc = qdio_sync_output_queue(q);
1288 	} else if (count < QDIO_MAX_BUFFERS_PER_Q &&
1289 		   get_buf_state(q, prev_buf(bufnr), &state, 0) > 0 &&
1290 		   state == SLSB_CU_OUTPUT_PRIMED) {
1291 		/* The previous buffer is not processed yet, tack on. */
1292 		qperf_inc(q, fast_requeue);
1293 	} else {
1294 		rc = qdio_kick_outbound_q(q, count, 0);
1295 	}
1296 
1297 	return rc;
1298 }
1299 
1300 /**
1301  * qdio_add_bufs_to_output_queue - process buffers on an Output Queue
1302  * @cdev: associated ccw_device for the qdio subchannel
1303  * @q_nr: queue number
1304  * @bufnr: buffer number
1305  * @count: how many buffers to process
1306  * @aob: asynchronous operation block
1307  */
1308 int qdio_add_bufs_to_output_queue(struct ccw_device *cdev, unsigned int q_nr,
1309 				  unsigned int bufnr, unsigned int count,
1310 				  struct qaob *aob)
1311 {
1312 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
1313 
1314 	if (bufnr >= QDIO_MAX_BUFFERS_PER_Q || count > QDIO_MAX_BUFFERS_PER_Q)
1315 		return -EINVAL;
1316 
1317 	if (!irq_ptr)
1318 		return -ENODEV;
1319 
1320 	DBF_DEV_EVENT(DBF_INFO, irq_ptr, "addo b:%02x c:%02x", bufnr, count);
1321 
1322 	if (irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)
1323 		return -EIO;
1324 	if (!count)
1325 		return 0;
1326 
1327 	return handle_outbound(irq_ptr->output_qs[q_nr], bufnr, count, aob);
1328 }
1329 EXPORT_SYMBOL_GPL(qdio_add_bufs_to_output_queue);
1330 
1331 /**
1332  * qdio_start_irq - enable interrupt processing for the device
1333  * @cdev: associated ccw_device for the qdio subchannel
1334  *
1335  * Return codes
1336  *   0 - success
1337  *   1 - irqs not started since new data is available
1338  */
1339 int qdio_start_irq(struct ccw_device *cdev)
1340 {
1341 	struct qdio_q *q;
1342 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
1343 	unsigned int i;
1344 
1345 	if (!irq_ptr)
1346 		return -ENODEV;
1347 
1348 	for_each_input_queue(irq_ptr, q, i)
1349 		qdio_stop_polling(q);
1350 
1351 	clear_bit(QDIO_IRQ_DISABLED, &irq_ptr->poll_state);
1352 
1353 	/*
1354 	 * We need to check again to not lose initiative after
1355 	 * resetting the ACK state.
1356 	 */
1357 	if (test_nonshared_ind(irq_ptr))
1358 		goto rescan;
1359 
1360 	for_each_input_queue(irq_ptr, q, i) {
1361 		if (!qdio_inbound_q_done(q, q->first_to_check))
1362 			goto rescan;
1363 	}
1364 
1365 	return 0;
1366 
1367 rescan:
1368 	if (test_and_set_bit(QDIO_IRQ_DISABLED, &irq_ptr->poll_state))
1369 		return 0;
1370 	else
1371 		return 1;
1372 
1373 }
1374 EXPORT_SYMBOL(qdio_start_irq);
1375 
1376 /**
1377  * qdio_stop_irq - disable interrupt processing for the device
1378  * @cdev: associated ccw_device for the qdio subchannel
1379  *
1380  * Return codes
1381  *   0 - interrupts were already disabled
1382  *   1 - interrupts successfully disabled
1383  */
1384 int qdio_stop_irq(struct ccw_device *cdev)
1385 {
1386 	struct qdio_irq *irq_ptr = cdev->private->qdio_data;
1387 
1388 	if (!irq_ptr)
1389 		return -ENODEV;
1390 
1391 	if (test_and_set_bit(QDIO_IRQ_DISABLED, &irq_ptr->poll_state))
1392 		return 0;
1393 	else
1394 		return 1;
1395 }
1396 EXPORT_SYMBOL(qdio_stop_irq);
1397 
1398 static int __init init_QDIO(void)
1399 {
1400 	int rc;
1401 
1402 	rc = qdio_debug_init();
1403 	if (rc)
1404 		return rc;
1405 	rc = qdio_setup_init();
1406 	if (rc)
1407 		goto out_debug;
1408 	rc = qdio_thinint_init();
1409 	if (rc)
1410 		goto out_cache;
1411 	return 0;
1412 
1413 out_cache:
1414 	qdio_setup_exit();
1415 out_debug:
1416 	qdio_debug_exit();
1417 	return rc;
1418 }
1419 
1420 static void __exit exit_QDIO(void)
1421 {
1422 	qdio_thinint_exit();
1423 	qdio_setup_exit();
1424 	qdio_debug_exit();
1425 }
1426 
1427 module_init(init_QDIO);
1428 module_exit(exit_QDIO);
1429