xref: /linux/drivers/s390/scsi/zfcp_qdio.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 /*
2  * linux/drivers/s390/scsi/zfcp_qdio.c
3  *
4  * FCP adapter driver for IBM eServer zSeries
5  *
6  * QDIO related routines
7  *
8  * (C) Copyright IBM Corp. 2002, 2004
9  *
10  * Authors:
11  *      Martin Peschke <mpeschke@de.ibm.com>
12  *      Raimund Schroeder <raimund.schroeder@de.ibm.com>
13  *      Wolfgang Taphorn
14  *      Heiko Carstens <heiko.carstens@de.ibm.com>
15  *      Andreas Herrmann <aherrman@de.ibm.com>
16  *
17  * This program is free software; you can redistribute it and/or modify
18  * it under the terms of the GNU General Public License as published by
19  * the Free Software Foundation; either version 2, or (at your option)
20  * any later version.
21  *
22  * This program is distributed in the hope that it will be useful,
23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25  * GNU General Public License for more details.
26  *
27  * You should have received a copy of the GNU General Public License
28  * along with this program; if not, write to the Free Software
29  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
30  */
31 
32 #include "zfcp_ext.h"
33 
34 static inline void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *, int);
35 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_get
36 	(struct zfcp_qdio_queue *, int, int);
37 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_resp
38 	(struct zfcp_fsf_req *, int, int);
39 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
40 	(struct zfcp_fsf_req *, unsigned long);
41 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
42 	(struct zfcp_fsf_req *, unsigned long);
43 static inline int zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *, int, int);
44 static inline int zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *);
45 static inline void zfcp_qdio_sbale_fill
46 	(struct zfcp_fsf_req *, unsigned long, void *, int);
47 static inline int zfcp_qdio_sbals_from_segment
48 	(struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
49 static inline int zfcp_qdio_sbals_from_buffer
50 	(struct zfcp_fsf_req *, unsigned long, void *, unsigned long, int);
51 
52 static qdio_handler_t zfcp_qdio_request_handler;
53 static qdio_handler_t zfcp_qdio_response_handler;
54 static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
55 	unsigned int, unsigned int, unsigned int, int, int);
56 
57 #define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_QDIO
58 
59 /*
60  * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
61  * array in the adapter struct.
62  * Cur_buf is the pointer array and count can be any number of required
63  * buffers, the page-fitting arithmetic is done entirely within this funciton.
64  *
65  * returns:	number of buffers allocated
66  * locks:       must only be called with zfcp_data.config_sema taken
67  */
68 static int
69 zfcp_qdio_buffers_enqueue(struct qdio_buffer **cur_buf, int count)
70 {
71 	int buf_pos;
72 	int qdio_buffers_per_page;
73 	int page_pos = 0;
74 	struct qdio_buffer *first_in_page = NULL;
75 
76 	qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
77 	ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
78 
79 	for (buf_pos = 0; buf_pos < count; buf_pos++) {
80 		if (page_pos == 0) {
81 			cur_buf[buf_pos] = (struct qdio_buffer *)
82 			    get_zeroed_page(GFP_KERNEL);
83 			if (cur_buf[buf_pos] == NULL) {
84 				ZFCP_LOG_INFO("error: allocation of "
85 					      "QDIO buffer failed \n");
86 				goto out;
87 			}
88 			first_in_page = cur_buf[buf_pos];
89 		} else {
90 			cur_buf[buf_pos] = first_in_page + page_pos;
91 
92 		}
93 		/* was initialised to zero */
94 		page_pos++;
95 		page_pos %= qdio_buffers_per_page;
96 	}
97  out:
98 	return buf_pos;
99 }
100 
101 /*
102  * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
103  * in the adapter struct cur_buf is the pointer array and count can be any
104  * number of buffers in the array that should be freed starting from buffer 0
105  *
106  * locks:       must only be called with zfcp_data.config_sema taken
107  */
108 static void
109 zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count)
110 {
111 	int buf_pos;
112 	int qdio_buffers_per_page;
113 
114 	qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
115 	ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
116 
117 	for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page)
118 		free_page((unsigned long) cur_buf[buf_pos]);
119 	return;
120 }
121 
122 /* locks:       must only be called with zfcp_data.config_sema taken */
123 int
124 zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
125 {
126 	int buffer_count;
127 	int retval = 0;
128 
129 	buffer_count =
130 	    zfcp_qdio_buffers_enqueue(&(adapter->request_queue.buffer[0]),
131 				      QDIO_MAX_BUFFERS_PER_Q);
132 	if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
133 		ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for request "
134 			       "queue\n", buffer_count);
135 		zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
136 					  buffer_count);
137 		retval = -ENOMEM;
138 		goto out;
139 	}
140 
141 	buffer_count =
142 	    zfcp_qdio_buffers_enqueue(&(adapter->response_queue.buffer[0]),
143 				      QDIO_MAX_BUFFERS_PER_Q);
144 	if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
145 		ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for response "
146 			       "queue", buffer_count);
147 		zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
148 					  buffer_count);
149 		ZFCP_LOG_TRACE("freeing request_queue buffers\n");
150 		zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
151 					  QDIO_MAX_BUFFERS_PER_Q);
152 		retval = -ENOMEM;
153 		goto out;
154 	}
155  out:
156 	return retval;
157 }
158 
159 /* locks:       must only be called with zfcp_data.config_sema taken */
160 void
161 zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
162 {
163 	ZFCP_LOG_TRACE("freeing request_queue buffers\n");
164 	zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
165 				  QDIO_MAX_BUFFERS_PER_Q);
166 
167 	ZFCP_LOG_TRACE("freeing response_queue buffers\n");
168 	zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
169 				  QDIO_MAX_BUFFERS_PER_Q);
170 }
171 
172 int
173 zfcp_qdio_allocate(struct zfcp_adapter *adapter)
174 {
175 	struct qdio_initialize *init_data;
176 
177 	init_data = &adapter->qdio_init_data;
178 
179 	init_data->cdev = adapter->ccw_device;
180 	init_data->q_format = QDIO_SCSI_QFMT;
181 	memcpy(init_data->adapter_name, &adapter->name, 8);
182 	init_data->qib_param_field_format = 0;
183 	init_data->qib_param_field = NULL;
184 	init_data->input_slib_elements = NULL;
185 	init_data->output_slib_elements = NULL;
186 	init_data->min_input_threshold = ZFCP_MIN_INPUT_THRESHOLD;
187 	init_data->max_input_threshold = ZFCP_MAX_INPUT_THRESHOLD;
188 	init_data->min_output_threshold = ZFCP_MIN_OUTPUT_THRESHOLD;
189 	init_data->max_output_threshold = ZFCP_MAX_OUTPUT_THRESHOLD;
190 	init_data->no_input_qs = 1;
191 	init_data->no_output_qs = 1;
192 	init_data->input_handler = zfcp_qdio_response_handler;
193 	init_data->output_handler = zfcp_qdio_request_handler;
194 	init_data->int_parm = (unsigned long) adapter;
195 	init_data->flags = QDIO_INBOUND_0COPY_SBALS |
196 	    QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
197 	init_data->input_sbal_addr_array =
198 	    (void **) (adapter->response_queue.buffer);
199 	init_data->output_sbal_addr_array =
200 	    (void **) (adapter->request_queue.buffer);
201 
202 	return qdio_allocate(init_data);
203 }
204 
205 /*
206  * function:   	zfcp_qdio_handler_error_check
207  *
208  * purpose:     called by the response handler to determine error condition
209  *
210  * returns:	error flag
211  *
212  */
213 static inline int
214 zfcp_qdio_handler_error_check(struct zfcp_adapter *adapter, unsigned int status,
215 			      unsigned int qdio_error, unsigned int siga_error,
216 			      int first_element, int elements_processed)
217 {
218 	int retval = 0;
219 
220 	if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
221 		retval = -EIO;
222 
223 		ZFCP_LOG_INFO("QDIO problem occurred (status=0x%x, "
224 			      "qdio_error=0x%x, siga_error=0x%x)\n",
225 			      status, qdio_error, siga_error);
226 
227 		zfcp_hba_dbf_event_qdio(adapter, status, qdio_error, siga_error,
228 				first_element, elements_processed);
229                /*
230                	* Restarting IO on the failed adapter from scratch.
231                 * Since we have been using this adapter, it is save to assume
232                 * that it is not failed but recoverable. The card seems to
233                 * report link-up events by self-initiated queue shutdown.
234                 * That is why we need to clear the the link-down flag
235                 * which is set again in case we have missed by a mile.
236                 */
237                zfcp_erp_adapter_reopen(
238                        adapter,
239                        ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
240                        ZFCP_STATUS_COMMON_ERP_FAILED);
241 	}
242 	return retval;
243 }
244 
245 /*
246  * function:    zfcp_qdio_request_handler
247  *
248  * purpose:	is called by QDIO layer for completed SBALs in request queue
249  *
250  * returns:	(void)
251  */
252 static void
253 zfcp_qdio_request_handler(struct ccw_device *ccw_device,
254 			  unsigned int status,
255 			  unsigned int qdio_error,
256 			  unsigned int siga_error,
257 			  unsigned int queue_number,
258 			  int first_element,
259 			  int elements_processed,
260 			  unsigned long int_parm)
261 {
262 	struct zfcp_adapter *adapter;
263 	struct zfcp_qdio_queue *queue;
264 
265 	adapter = (struct zfcp_adapter *) int_parm;
266 	queue = &adapter->request_queue;
267 
268 	ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
269 		       zfcp_get_busid_by_adapter(adapter),
270 		       first_element, elements_processed);
271 
272 	if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
273 						   siga_error, first_element,
274 						   elements_processed)))
275 		goto out;
276 	/*
277 	 * we stored address of struct zfcp_adapter  data structure
278 	 * associated with irq in int_parm
279 	 */
280 
281 	/* cleanup all SBALs being program-owned now */
282 	zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
283 
284 	/* increase free space in outbound queue */
285 	atomic_add(elements_processed, &queue->free_count);
286 	ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
287 	wake_up(&adapter->request_wq);
288 	ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
289 		       elements_processed, atomic_read(&queue->free_count));
290  out:
291 	return;
292 }
293 
294 /*
295  * function:   	zfcp_qdio_response_handler
296  *
297  * purpose:	is called by QDIO layer for completed SBALs in response queue
298  *
299  * returns:	(void)
300  */
301 static void
302 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
303 			   unsigned int status,
304 			   unsigned int qdio_error,
305 			   unsigned int siga_error,
306 			   unsigned int queue_number,
307 			   int first_element,
308 			   int elements_processed,
309 			   unsigned long int_parm)
310 {
311 	struct zfcp_adapter *adapter;
312 	struct zfcp_qdio_queue *queue;
313 	int buffer_index;
314 	int i;
315 	struct qdio_buffer *buffer;
316 	int retval = 0;
317 	u8 count;
318 	u8 start;
319 	volatile struct qdio_buffer_element *buffere = NULL;
320 	int buffere_index;
321 
322 	adapter = (struct zfcp_adapter *) int_parm;
323 	queue = &adapter->response_queue;
324 
325 	if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
326 						   siga_error, first_element,
327 						   elements_processed)))
328 		goto out;
329 
330 	/*
331 	 * we stored address of struct zfcp_adapter  data structure
332 	 * associated with irq in int_parm
333 	 */
334 
335 	buffere = &(queue->buffer[first_element]->element[0]);
336 	ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
337 	/*
338 	 * go through all SBALs from input queue currently
339 	 * returned by QDIO layer
340 	 */
341 
342 	for (i = 0; i < elements_processed; i++) {
343 
344 		buffer_index = first_element + i;
345 		buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
346 		buffer = queue->buffer[buffer_index];
347 
348 		/* go through all SBALEs of SBAL */
349 		for (buffere_index = 0;
350 		     buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
351 		     buffere_index++) {
352 
353 			/* look for QDIO request identifiers in SB */
354 			buffere = &buffer->element[buffere_index];
355 			retval = zfcp_qdio_reqid_check(adapter,
356 						       (void *) buffere->addr);
357 
358 			if (retval) {
359 				ZFCP_LOG_NORMAL("bug: unexpected inbound "
360 						"packet on adapter %s "
361 						"(reqid=0x%lx, "
362 						"first_element=%d, "
363 						"elements_processed=%d)\n",
364 						zfcp_get_busid_by_adapter(adapter),
365 						(unsigned long) buffere->addr,
366 						first_element,
367 						elements_processed);
368 				ZFCP_LOG_NORMAL("hex dump of inbound buffer "
369 						"at address %p "
370 						"(buffer_index=%d, "
371 						"buffere_index=%d)\n", buffer,
372 						buffer_index, buffere_index);
373 				ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
374 					      (char *) buffer, SBAL_SIZE);
375 			}
376 			/*
377 			 * A single used SBALE per inbound SBALE has been
378 			 * implemented by QDIO so far. Hope they will
379 			 * do some optimisation. Will need to change to
380 			 * unlikely() then.
381 			 */
382 			if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
383 				break;
384 		};
385 
386 		if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
387 			ZFCP_LOG_NORMAL("bug: End of inbound data "
388 					"not marked!\n");
389 		}
390 	}
391 
392 	/*
393 	 * put range of SBALs back to response queue
394 	 * (including SBALs which have already been free before)
395 	 */
396 	count = atomic_read(&queue->free_count) + elements_processed;
397 	start = queue->free_index;
398 
399 	ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
400 		       "queue_no=%i, index_in_queue=%i, count=%i, "
401 		       "buffers=0x%lx\n",
402 		       zfcp_get_busid_by_adapter(adapter),
403 		       QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
404 		       0, start, count, (unsigned long) &queue->buffer[start]);
405 
406 	retval = do_QDIO(ccw_device,
407 			 QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
408 			 0, start, count, NULL);
409 
410 	if (unlikely(retval)) {
411 		atomic_set(&queue->free_count, count);
412 		ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
413 			       "queues may be down "
414 			       "(count=%d, start=%d, retval=%d)\n",
415 			       count, start, retval);
416 	} else {
417 		queue->free_index += count;
418 		queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
419 		atomic_set(&queue->free_count, 0);
420 		ZFCP_LOG_TRACE("%i buffers enqueued to response "
421 			       "queue at position %i\n", count, start);
422 	}
423  out:
424 	return;
425 }
426 
427 /*
428  * function:	zfcp_qdio_reqid_check
429  *
430  * purpose:	checks for valid reqids or unsolicited status
431  *
432  * returns:	0 - valid request id or unsolicited status
433  *		!0 - otherwise
434  */
435 int
436 zfcp_qdio_reqid_check(struct zfcp_adapter *adapter, void *sbale_addr)
437 {
438 	struct zfcp_fsf_req *fsf_req;
439 
440 	/* invalid (per convention used in this driver) */
441 	if (unlikely(!sbale_addr)) {
442 		ZFCP_LOG_NORMAL("bug: invalid reqid\n");
443 		return -EINVAL;
444 	}
445 
446 	/* valid request id and thus (hopefully :) valid fsf_req address */
447 	fsf_req = (struct zfcp_fsf_req *) sbale_addr;
448 
449 	/* serialize with zfcp_fsf_req_dismiss_all */
450 	spin_lock(&adapter->fsf_req_list_lock);
451 	if (list_empty(&adapter->fsf_req_list_head)) {
452 		spin_unlock(&adapter->fsf_req_list_lock);
453 		return 0;
454 	}
455 	list_del(&fsf_req->list);
456 	atomic_dec(&adapter->fsf_reqs_active);
457 	spin_unlock(&adapter->fsf_req_list_lock);
458 
459 	if (unlikely(adapter != fsf_req->adapter)) {
460 		ZFCP_LOG_NORMAL("bug: invalid reqid (fsf_req=%p, "
461 				"fsf_req->adapter=%p, adapter=%p)\n",
462 				fsf_req, fsf_req->adapter, adapter);
463 		return -EINVAL;
464 	}
465 
466 	/* finish the FSF request */
467 	zfcp_fsf_req_complete(fsf_req);
468 
469 	return 0;
470 }
471 
472 /**
473  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
474  * @queue: queue from which SBALE should be returned
475  * @sbal: specifies number of SBAL in queue
476  * @sbale: specifes number of SBALE in SBAL
477  */
478 static inline volatile struct qdio_buffer_element *
479 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
480 {
481 	return &queue->buffer[sbal]->element[sbale];
482 }
483 
484 /**
485  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
486  *	a struct zfcp_fsf_req
487  */
488 inline volatile struct qdio_buffer_element *
489 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
490 {
491 	return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
492 				   sbal, sbale);
493 }
494 
495 /**
496  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
497  *	a struct zfcp_fsf_req
498  */
499 static inline volatile struct qdio_buffer_element *
500 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
501 {
502 	return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
503 				   sbal, sbale);
504 }
505 
506 /**
507  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
508  *	a struct zfcp_fsf_req
509  */
510 inline volatile struct qdio_buffer_element *
511 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
512 {
513 	return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
514 				   fsf_req->sbale_curr);
515 }
516 
517 /**
518  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
519  *	on the request_queue for a struct zfcp_fsf_req
520  * @fsf_req: the number of the last SBAL that can be used is stored herein
521  * @max_sbals: used to pass an upper limit for the number of SBALs
522  *
523  * Note: We can assume at least one free SBAL in the request_queue when called.
524  */
525 static inline void
526 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
527 {
528 	int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
529 	count = min(count, max_sbals);
530 	fsf_req->sbal_last  = fsf_req->sbal_first;
531 	fsf_req->sbal_last += (count - 1);
532 	fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
533 }
534 
535 /**
536  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
537  *	request
538  * @fsf_req: zfcp_fsf_req to be processed
539  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
540  *
541  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
542  */
543 static inline volatile struct qdio_buffer_element *
544 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
545 {
546 	volatile struct qdio_buffer_element *sbale;
547 
548 	/* set last entry flag in current SBALE of current SBAL */
549 	sbale = zfcp_qdio_sbale_curr(fsf_req);
550 	sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
551 
552 	/* don't exceed last allowed SBAL */
553 	if (fsf_req->sbal_curr == fsf_req->sbal_last)
554 		return NULL;
555 
556 	/* set chaining flag in first SBALE of current SBAL */
557 	sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
558 	sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
559 
560 	/* calculate index of next SBAL */
561 	fsf_req->sbal_curr++;
562 	fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
563 
564 	/* keep this requests number of SBALs up-to-date */
565 	fsf_req->sbal_number++;
566 
567 	/* start at first SBALE of new SBAL */
568 	fsf_req->sbale_curr = 0;
569 
570 	/* set storage-block type for new SBAL */
571 	sbale = zfcp_qdio_sbale_curr(fsf_req);
572 	sbale->flags |= sbtype;
573 
574 	return sbale;
575 }
576 
577 /**
578  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
579  */
580 static inline volatile struct qdio_buffer_element *
581 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
582 {
583 	if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
584 		return zfcp_qdio_sbal_chain(fsf_req, sbtype);
585 
586 	fsf_req->sbale_curr++;
587 
588 	return zfcp_qdio_sbale_curr(fsf_req);
589 }
590 
591 /**
592  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
593  *	with zero from
594  */
595 static inline int
596 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
597 {
598 	struct qdio_buffer **buf = queue->buffer;
599 	int curr = first;
600 	int count = 0;
601 
602 	for(;;) {
603 		curr %= QDIO_MAX_BUFFERS_PER_Q;
604 		count++;
605 		memset(buf[curr], 0, sizeof(struct qdio_buffer));
606 		if (curr == last)
607 			break;
608 		curr++;
609 	}
610 	return count;
611 }
612 
613 
614 /**
615  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
616  */
617 static inline int
618 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
619 {
620 	return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
621 				    fsf_req->sbal_first, fsf_req->sbal_curr);
622 }
623 
624 
625 /**
626  * zfcp_qdio_sbale_fill - set address and lenght in current SBALE
627  *	on request_queue
628  */
629 static inline void
630 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
631 		     void *addr, int length)
632 {
633 	volatile struct qdio_buffer_element *sbale;
634 
635 	sbale = zfcp_qdio_sbale_curr(fsf_req);
636 	sbale->addr = addr;
637 	sbale->length = length;
638 }
639 
640 /**
641  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
642  * @fsf_req: request to be processed
643  * @sbtype: SBALE flags
644  * @start_addr: address of memory segment
645  * @total_length: length of memory segment
646  *
647  * Alignment and length of the segment determine how many SBALEs are needed
648  * for the memory segment.
649  */
650 static inline int
651 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
652 			     void *start_addr, unsigned long total_length)
653 {
654 	unsigned long remaining, length;
655 	void *addr;
656 
657 	/* split segment up heeding page boundaries */
658 	for (addr = start_addr, remaining = total_length; remaining > 0;
659 	     addr += length, remaining -= length) {
660 		/* get next free SBALE for new piece */
661 		if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
662 			/* no SBALE left, clean up and leave */
663 			zfcp_qdio_sbals_wipe(fsf_req);
664 			return -EINVAL;
665 		}
666 		/* calculate length of new piece */
667 		length = min(remaining,
668 			     (PAGE_SIZE - ((unsigned long) addr &
669 					   (PAGE_SIZE - 1))));
670 		/* fill current SBALE with calculated piece */
671 		zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
672 	}
673 	return total_length;
674 }
675 
676 
677 /**
678  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
679  * @fsf_req: request to be processed
680  * @sbtype: SBALE flags
681  * @sg: scatter-gather list
682  * @sg_count: number of elements in scatter-gather list
683  * @max_sbals: upper bound for number of SBALs to be used
684  */
685 inline int
686 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
687                         struct scatterlist *sg,	int sg_count, int max_sbals)
688 {
689 	int sg_index;
690 	struct scatterlist *sg_segment;
691 	int retval;
692 	volatile struct qdio_buffer_element *sbale;
693 	int bytes = 0;
694 
695 	/* figure out last allowed SBAL */
696 	zfcp_qdio_sbal_limit(fsf_req, max_sbals);
697 
698 	/* set storage-block type for current SBAL */
699 	sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
700 	sbale->flags |= sbtype;
701 
702 	/* process all segements of scatter-gather list */
703 	for (sg_index = 0, sg_segment = sg, bytes = 0;
704 	     sg_index < sg_count;
705 	     sg_index++, sg_segment++) {
706 		retval = zfcp_qdio_sbals_from_segment(
707 				fsf_req,
708 				sbtype,
709 				zfcp_sg_to_address(sg_segment),
710 				sg_segment->length);
711 		if (retval < 0) {
712 			bytes = retval;
713 			goto out;
714 		} else
715                         bytes += retval;
716 	}
717 	/* assume that no other SBALEs are to follow in the same SBAL */
718 	sbale = zfcp_qdio_sbale_curr(fsf_req);
719 	sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
720 out:
721 	return bytes;
722 }
723 
724 
725 /**
726  * zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
727  * @fsf_req: request to be processed
728  * @sbtype: SBALE flags
729  * @buffer: data buffer
730  * @length: length of buffer
731  * @max_sbals: upper bound for number of SBALs to be used
732  */
733 static inline int
734 zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
735 			    void *buffer, unsigned long length, int max_sbals)
736 {
737 	struct scatterlist sg_segment;
738 
739 	zfcp_address_to_sg(buffer, &sg_segment);
740 	sg_segment.length = length;
741 
742 	return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
743                                        max_sbals);
744 }
745 
746 
747 /**
748  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
749  * @fsf_req: request to be processed
750  * @sbtype: SBALE flags
751  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
752  *	to fill SBALs
753  */
754 inline int
755 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
756 			      unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
757 {
758 	if (scsi_cmnd->use_sg) {
759 		return zfcp_qdio_sbals_from_sg(fsf_req,	sbtype,
760                                                (struct scatterlist *)
761                                                scsi_cmnd->request_buffer,
762                                                scsi_cmnd->use_sg,
763                                                ZFCP_MAX_SBALS_PER_REQ);
764 	} else {
765                 return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
766                                                    scsi_cmnd->request_buffer,
767                                                    scsi_cmnd->request_bufflen,
768                                                    ZFCP_MAX_SBALS_PER_REQ);
769 	}
770 }
771 
772 /**
773  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
774  */
775 int
776 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
777 			struct zfcp_fsf_req *fsf_req)
778 {
779 	int new_distance_from_int;
780 	int pci_pos;
781 	volatile struct qdio_buffer_element *sbale;
782 
783 	new_distance_from_int = req_queue->distance_from_int +
784                 fsf_req->sbal_number;
785 
786 	if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
787 		new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
788                 pci_pos  = fsf_req->sbal_first;
789 		pci_pos += fsf_req->sbal_number;
790 		pci_pos -= new_distance_from_int;
791 		pci_pos -= 1;
792 		pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
793 		sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
794 		sbale->flags |= SBAL_FLAGS0_PCI;
795 	}
796 	return new_distance_from_int;
797 }
798 
799 /*
800  * function:	zfcp_zero_sbals
801  *
802  * purpose:	zeros specified range of SBALs
803  *
804  * returns:
805  */
806 void
807 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
808 {
809 	int cur_pos;
810 	int index;
811 
812 	for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
813 		index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
814 		memset(buf[index], 0, sizeof (struct qdio_buffer));
815 		ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
816 			       index, buf[index]);
817 	}
818 }
819 
820 #undef ZFCP_LOG_AREA
821