xref: /openbmc/linux/drivers/s390/scsi/zfcp_qdio.c (revision 87c2ce3b)
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 #define ZFCP_QDIO_C_REVISION "$Revision: 1.20 $"
33 
34 #include "zfcp_ext.h"
35 
36 static inline void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *, int);
37 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_get
38 	(struct zfcp_qdio_queue *, int, int);
39 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_resp
40 	(struct zfcp_fsf_req *, int, int);
41 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
42 	(struct zfcp_fsf_req *, unsigned long);
43 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
44 	(struct zfcp_fsf_req *, unsigned long);
45 static inline int zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *, int, int);
46 static inline int zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *);
47 static inline void zfcp_qdio_sbale_fill
48 	(struct zfcp_fsf_req *, unsigned long, void *, int);
49 static inline int zfcp_qdio_sbals_from_segment
50 	(struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
51 static inline int zfcp_qdio_sbals_from_buffer
52 	(struct zfcp_fsf_req *, unsigned long, void *, unsigned long, int);
53 
54 static qdio_handler_t zfcp_qdio_request_handler;
55 static qdio_handler_t zfcp_qdio_response_handler;
56 static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
57 	unsigned int, unsigned int, unsigned int, int, int);
58 
59 #define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_QDIO
60 
61 /*
62  * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
63  * array in the adapter struct.
64  * Cur_buf is the pointer array and count can be any number of required
65  * buffers, the page-fitting arithmetic is done entirely within this funciton.
66  *
67  * returns:	number of buffers allocated
68  * locks:       must only be called with zfcp_data.config_sema taken
69  */
70 static int
71 zfcp_qdio_buffers_enqueue(struct qdio_buffer **cur_buf, int count)
72 {
73 	int buf_pos;
74 	int qdio_buffers_per_page;
75 	int page_pos = 0;
76 	struct qdio_buffer *first_in_page = NULL;
77 
78 	qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
79 	ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
80 
81 	for (buf_pos = 0; buf_pos < count; buf_pos++) {
82 		if (page_pos == 0) {
83 			cur_buf[buf_pos] = (struct qdio_buffer *)
84 			    get_zeroed_page(GFP_KERNEL);
85 			if (cur_buf[buf_pos] == NULL) {
86 				ZFCP_LOG_INFO("error: allocation of "
87 					      "QDIO buffer failed \n");
88 				goto out;
89 			}
90 			first_in_page = cur_buf[buf_pos];
91 		} else {
92 			cur_buf[buf_pos] = first_in_page + page_pos;
93 
94 		}
95 		/* was initialised to zero */
96 		page_pos++;
97 		page_pos %= qdio_buffers_per_page;
98 	}
99  out:
100 	return buf_pos;
101 }
102 
103 /*
104  * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
105  * in the adapter struct cur_buf is the pointer array and count can be any
106  * number of buffers in the array that should be freed starting from buffer 0
107  *
108  * locks:       must only be called with zfcp_data.config_sema taken
109  */
110 static void
111 zfcp_qdio_buffers_dequeue(struct qdio_buffer **cur_buf, int count)
112 {
113 	int buf_pos;
114 	int qdio_buffers_per_page;
115 
116 	qdio_buffers_per_page = PAGE_SIZE / sizeof (struct qdio_buffer);
117 	ZFCP_LOG_TRACE("buffers_per_page=%d\n", qdio_buffers_per_page);
118 
119 	for (buf_pos = 0; buf_pos < count; buf_pos += qdio_buffers_per_page)
120 		free_page((unsigned long) cur_buf[buf_pos]);
121 	return;
122 }
123 
124 /* locks:       must only be called with zfcp_data.config_sema taken */
125 int
126 zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
127 {
128 	int buffer_count;
129 	int retval = 0;
130 
131 	buffer_count =
132 	    zfcp_qdio_buffers_enqueue(&(adapter->request_queue.buffer[0]),
133 				      QDIO_MAX_BUFFERS_PER_Q);
134 	if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
135 		ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for request "
136 			       "queue\n", buffer_count);
137 		zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
138 					  buffer_count);
139 		retval = -ENOMEM;
140 		goto out;
141 	}
142 
143 	buffer_count =
144 	    zfcp_qdio_buffers_enqueue(&(adapter->response_queue.buffer[0]),
145 				      QDIO_MAX_BUFFERS_PER_Q);
146 	if (buffer_count < QDIO_MAX_BUFFERS_PER_Q) {
147 		ZFCP_LOG_DEBUG("only %d QDIO buffers allocated for response "
148 			       "queue", buffer_count);
149 		zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
150 					  buffer_count);
151 		ZFCP_LOG_TRACE("freeing request_queue buffers\n");
152 		zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
153 					  QDIO_MAX_BUFFERS_PER_Q);
154 		retval = -ENOMEM;
155 		goto out;
156 	}
157  out:
158 	return retval;
159 }
160 
161 /* locks:       must only be called with zfcp_data.config_sema taken */
162 void
163 zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
164 {
165 	ZFCP_LOG_TRACE("freeing request_queue buffers\n");
166 	zfcp_qdio_buffers_dequeue(&(adapter->request_queue.buffer[0]),
167 				  QDIO_MAX_BUFFERS_PER_Q);
168 
169 	ZFCP_LOG_TRACE("freeing response_queue buffers\n");
170 	zfcp_qdio_buffers_dequeue(&(adapter->response_queue.buffer[0]),
171 				  QDIO_MAX_BUFFERS_PER_Q);
172 }
173 
174 int
175 zfcp_qdio_allocate(struct zfcp_adapter *adapter)
176 {
177 	struct qdio_initialize *init_data;
178 
179 	init_data = &adapter->qdio_init_data;
180 
181 	init_data->cdev = adapter->ccw_device;
182 	init_data->q_format = QDIO_SCSI_QFMT;
183 	memcpy(init_data->adapter_name, &adapter->name, 8);
184 	init_data->qib_param_field_format = 0;
185 	init_data->qib_param_field = NULL;
186 	init_data->input_slib_elements = NULL;
187 	init_data->output_slib_elements = NULL;
188 	init_data->min_input_threshold = ZFCP_MIN_INPUT_THRESHOLD;
189 	init_data->max_input_threshold = ZFCP_MAX_INPUT_THRESHOLD;
190 	init_data->min_output_threshold = ZFCP_MIN_OUTPUT_THRESHOLD;
191 	init_data->max_output_threshold = ZFCP_MAX_OUTPUT_THRESHOLD;
192 	init_data->no_input_qs = 1;
193 	init_data->no_output_qs = 1;
194 	init_data->input_handler = zfcp_qdio_response_handler;
195 	init_data->output_handler = zfcp_qdio_request_handler;
196 	init_data->int_parm = (unsigned long) adapter;
197 	init_data->flags = QDIO_INBOUND_0COPY_SBALS |
198 	    QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
199 	init_data->input_sbal_addr_array =
200 	    (void **) (adapter->response_queue.buffer);
201 	init_data->output_sbal_addr_array =
202 	    (void **) (adapter->request_queue.buffer);
203 
204 	return qdio_allocate(init_data);
205 }
206 
207 /*
208  * function:   	zfcp_qdio_handler_error_check
209  *
210  * purpose:     called by the response handler to determine error condition
211  *
212  * returns:	error flag
213  *
214  */
215 static inline int
216 zfcp_qdio_handler_error_check(struct zfcp_adapter *adapter, unsigned int status,
217 			      unsigned int qdio_error, unsigned int siga_error,
218 			      int first_element, int elements_processed)
219 {
220 	int retval = 0;
221 
222 	if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
223 		retval = -EIO;
224 
225 		ZFCP_LOG_INFO("QDIO problem occurred (status=0x%x, "
226 			      "qdio_error=0x%x, siga_error=0x%x)\n",
227 			      status, qdio_error, siga_error);
228 
229 		zfcp_hba_dbf_event_qdio(adapter, status, qdio_error, siga_error,
230 				first_element, elements_processed);
231                /*
232                	* Restarting IO on the failed adapter from scratch.
233                 * Since we have been using this adapter, it is save to assume
234                 * that it is not failed but recoverable. The card seems to
235                 * report link-up events by self-initiated queue shutdown.
236                 * That is why we need to clear the the link-down flag
237                 * which is set again in case we have missed by a mile.
238                 */
239                zfcp_erp_adapter_reopen(
240                        adapter,
241                        ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
242                        ZFCP_STATUS_COMMON_ERP_FAILED);
243 	}
244 	return retval;
245 }
246 
247 /*
248  * function:    zfcp_qdio_request_handler
249  *
250  * purpose:	is called by QDIO layer for completed SBALs in request queue
251  *
252  * returns:	(void)
253  */
254 static void
255 zfcp_qdio_request_handler(struct ccw_device *ccw_device,
256 			  unsigned int status,
257 			  unsigned int qdio_error,
258 			  unsigned int siga_error,
259 			  unsigned int queue_number,
260 			  int first_element,
261 			  int elements_processed,
262 			  unsigned long int_parm)
263 {
264 	struct zfcp_adapter *adapter;
265 	struct zfcp_qdio_queue *queue;
266 
267 	adapter = (struct zfcp_adapter *) int_parm;
268 	queue = &adapter->request_queue;
269 
270 	ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
271 		       zfcp_get_busid_by_adapter(adapter),
272 		       first_element, elements_processed);
273 
274 	if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
275 						   siga_error, first_element,
276 						   elements_processed)))
277 		goto out;
278 	/*
279 	 * we stored address of struct zfcp_adapter  data structure
280 	 * associated with irq in int_parm
281 	 */
282 
283 	/* cleanup all SBALs being program-owned now */
284 	zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
285 
286 	/* increase free space in outbound queue */
287 	atomic_add(elements_processed, &queue->free_count);
288 	ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
289 	wake_up(&adapter->request_wq);
290 	ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
291 		       elements_processed, atomic_read(&queue->free_count));
292  out:
293 	return;
294 }
295 
296 /*
297  * function:   	zfcp_qdio_response_handler
298  *
299  * purpose:	is called by QDIO layer for completed SBALs in response queue
300  *
301  * returns:	(void)
302  */
303 static void
304 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
305 			   unsigned int status,
306 			   unsigned int qdio_error,
307 			   unsigned int siga_error,
308 			   unsigned int queue_number,
309 			   int first_element,
310 			   int elements_processed,
311 			   unsigned long int_parm)
312 {
313 	struct zfcp_adapter *adapter;
314 	struct zfcp_qdio_queue *queue;
315 	int buffer_index;
316 	int i;
317 	struct qdio_buffer *buffer;
318 	int retval = 0;
319 	u8 count;
320 	u8 start;
321 	volatile struct qdio_buffer_element *buffere = NULL;
322 	int buffere_index;
323 
324 	adapter = (struct zfcp_adapter *) int_parm;
325 	queue = &adapter->response_queue;
326 
327 	if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
328 						   siga_error, first_element,
329 						   elements_processed)))
330 		goto out;
331 
332 	/*
333 	 * we stored address of struct zfcp_adapter  data structure
334 	 * associated with irq in int_parm
335 	 */
336 
337 	buffere = &(queue->buffer[first_element]->element[0]);
338 	ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
339 	/*
340 	 * go through all SBALs from input queue currently
341 	 * returned by QDIO layer
342 	 */
343 
344 	for (i = 0; i < elements_processed; i++) {
345 
346 		buffer_index = first_element + i;
347 		buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
348 		buffer = queue->buffer[buffer_index];
349 
350 		/* go through all SBALEs of SBAL */
351 		for (buffere_index = 0;
352 		     buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
353 		     buffere_index++) {
354 
355 			/* look for QDIO request identifiers in SB */
356 			buffere = &buffer->element[buffere_index];
357 			retval = zfcp_qdio_reqid_check(adapter,
358 						       (void *) buffere->addr);
359 
360 			if (retval) {
361 				ZFCP_LOG_NORMAL("bug: unexpected inbound "
362 						"packet on adapter %s "
363 						"(reqid=0x%lx, "
364 						"first_element=%d, "
365 						"elements_processed=%d)\n",
366 						zfcp_get_busid_by_adapter(adapter),
367 						(unsigned long) buffere->addr,
368 						first_element,
369 						elements_processed);
370 				ZFCP_LOG_NORMAL("hex dump of inbound buffer "
371 						"at address %p "
372 						"(buffer_index=%d, "
373 						"buffere_index=%d)\n", buffer,
374 						buffer_index, buffere_index);
375 				ZFCP_HEX_DUMP(ZFCP_LOG_LEVEL_NORMAL,
376 					      (char *) buffer, SBAL_SIZE);
377 			}
378 			/*
379 			 * A single used SBALE per inbound SBALE has been
380 			 * implemented by QDIO so far. Hope they will
381 			 * do some optimisation. Will need to change to
382 			 * unlikely() then.
383 			 */
384 			if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
385 				break;
386 		};
387 
388 		if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
389 			ZFCP_LOG_NORMAL("bug: End of inbound data "
390 					"not marked!\n");
391 		}
392 	}
393 
394 	/*
395 	 * put range of SBALs back to response queue
396 	 * (including SBALs which have already been free before)
397 	 */
398 	count = atomic_read(&queue->free_count) + elements_processed;
399 	start = queue->free_index;
400 
401 	ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
402 		       "queue_no=%i, index_in_queue=%i, count=%i, "
403 		       "buffers=0x%lx\n",
404 		       zfcp_get_busid_by_adapter(adapter),
405 		       QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
406 		       0, start, count, (unsigned long) &queue->buffer[start]);
407 
408 	retval = do_QDIO(ccw_device,
409 			 QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
410 			 0, start, count, NULL);
411 
412 	if (unlikely(retval)) {
413 		atomic_set(&queue->free_count, count);
414 		ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
415 			       "queues may be down "
416 			       "(count=%d, start=%d, retval=%d)\n",
417 			       count, start, retval);
418 	} else {
419 		queue->free_index += count;
420 		queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
421 		atomic_set(&queue->free_count, 0);
422 		ZFCP_LOG_TRACE("%i buffers enqueued to response "
423 			       "queue at position %i\n", count, start);
424 	}
425  out:
426 	return;
427 }
428 
429 /*
430  * function:	zfcp_qdio_reqid_check
431  *
432  * purpose:	checks for valid reqids or unsolicited status
433  *
434  * returns:	0 - valid request id or unsolicited status
435  *		!0 - otherwise
436  */
437 int
438 zfcp_qdio_reqid_check(struct zfcp_adapter *adapter, void *sbale_addr)
439 {
440 	struct zfcp_fsf_req *fsf_req;
441 
442 	/* invalid (per convention used in this driver) */
443 	if (unlikely(!sbale_addr)) {
444 		ZFCP_LOG_NORMAL("bug: invalid reqid\n");
445 		return -EINVAL;
446 	}
447 
448 	/* valid request id and thus (hopefully :) valid fsf_req address */
449 	fsf_req = (struct zfcp_fsf_req *) sbale_addr;
450 
451 	/* serialize with zfcp_fsf_req_dismiss_all */
452 	spin_lock(&adapter->fsf_req_list_lock);
453 	if (list_empty(&adapter->fsf_req_list_head)) {
454 		spin_unlock(&adapter->fsf_req_list_lock);
455 		return 0;
456 	}
457 	list_del(&fsf_req->list);
458 	atomic_dec(&adapter->fsf_reqs_active);
459 	spin_unlock(&adapter->fsf_req_list_lock);
460 
461 	if (unlikely(adapter != fsf_req->adapter)) {
462 		ZFCP_LOG_NORMAL("bug: invalid reqid (fsf_req=%p, "
463 				"fsf_req->adapter=%p, adapter=%p)\n",
464 				fsf_req, fsf_req->adapter, adapter);
465 		return -EINVAL;
466 	}
467 
468 	/* finish the FSF request */
469 	zfcp_fsf_req_complete(fsf_req);
470 
471 	return 0;
472 }
473 
474 /**
475  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
476  * @queue: queue from which SBALE should be returned
477  * @sbal: specifies number of SBAL in queue
478  * @sbale: specifes number of SBALE in SBAL
479  */
480 static inline volatile struct qdio_buffer_element *
481 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
482 {
483 	return &queue->buffer[sbal]->element[sbale];
484 }
485 
486 /**
487  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
488  *	a struct zfcp_fsf_req
489  */
490 inline volatile struct qdio_buffer_element *
491 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
492 {
493 	return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
494 				   sbal, sbale);
495 }
496 
497 /**
498  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
499  *	a struct zfcp_fsf_req
500  */
501 static inline volatile struct qdio_buffer_element *
502 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
503 {
504 	return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
505 				   sbal, sbale);
506 }
507 
508 /**
509  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
510  *	a struct zfcp_fsf_req
511  */
512 inline volatile struct qdio_buffer_element *
513 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
514 {
515 	return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
516 				   fsf_req->sbale_curr);
517 }
518 
519 /**
520  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
521  *	on the request_queue for a struct zfcp_fsf_req
522  * @fsf_req: the number of the last SBAL that can be used is stored herein
523  * @max_sbals: used to pass an upper limit for the number of SBALs
524  *
525  * Note: We can assume at least one free SBAL in the request_queue when called.
526  */
527 static inline void
528 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
529 {
530 	int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
531 	count = min(count, max_sbals);
532 	fsf_req->sbal_last  = fsf_req->sbal_first;
533 	fsf_req->sbal_last += (count - 1);
534 	fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
535 }
536 
537 /**
538  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
539  *	request
540  * @fsf_req: zfcp_fsf_req to be processed
541  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
542  *
543  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
544  */
545 static inline volatile struct qdio_buffer_element *
546 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
547 {
548 	volatile struct qdio_buffer_element *sbale;
549 
550 	/* set last entry flag in current SBALE of current SBAL */
551 	sbale = zfcp_qdio_sbale_curr(fsf_req);
552 	sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
553 
554 	/* don't exceed last allowed SBAL */
555 	if (fsf_req->sbal_curr == fsf_req->sbal_last)
556 		return NULL;
557 
558 	/* set chaining flag in first SBALE of current SBAL */
559 	sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
560 	sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
561 
562 	/* calculate index of next SBAL */
563 	fsf_req->sbal_curr++;
564 	fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
565 
566 	/* keep this requests number of SBALs up-to-date */
567 	fsf_req->sbal_number++;
568 
569 	/* start at first SBALE of new SBAL */
570 	fsf_req->sbale_curr = 0;
571 
572 	/* set storage-block type for new SBAL */
573 	sbale = zfcp_qdio_sbale_curr(fsf_req);
574 	sbale->flags |= sbtype;
575 
576 	return sbale;
577 }
578 
579 /**
580  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
581  */
582 static inline volatile struct qdio_buffer_element *
583 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
584 {
585 	if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
586 		return zfcp_qdio_sbal_chain(fsf_req, sbtype);
587 
588 	fsf_req->sbale_curr++;
589 
590 	return zfcp_qdio_sbale_curr(fsf_req);
591 }
592 
593 /**
594  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
595  *	with zero from
596  */
597 static inline int
598 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
599 {
600 	struct qdio_buffer **buf = queue->buffer;
601 	int curr = first;
602 	int count = 0;
603 
604 	for(;;) {
605 		curr %= QDIO_MAX_BUFFERS_PER_Q;
606 		count++;
607 		memset(buf[curr], 0, sizeof(struct qdio_buffer));
608 		if (curr == last)
609 			break;
610 		curr++;
611 	}
612 	return count;
613 }
614 
615 
616 /**
617  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
618  */
619 static inline int
620 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
621 {
622 	return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
623 				    fsf_req->sbal_first, fsf_req->sbal_curr);
624 }
625 
626 
627 /**
628  * zfcp_qdio_sbale_fill - set address and lenght in current SBALE
629  *	on request_queue
630  */
631 static inline void
632 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
633 		     void *addr, int length)
634 {
635 	volatile struct qdio_buffer_element *sbale;
636 
637 	sbale = zfcp_qdio_sbale_curr(fsf_req);
638 	sbale->addr = addr;
639 	sbale->length = length;
640 }
641 
642 /**
643  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
644  * @fsf_req: request to be processed
645  * @sbtype: SBALE flags
646  * @start_addr: address of memory segment
647  * @total_length: length of memory segment
648  *
649  * Alignment and length of the segment determine how many SBALEs are needed
650  * for the memory segment.
651  */
652 static inline int
653 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
654 			     void *start_addr, unsigned long total_length)
655 {
656 	unsigned long remaining, length;
657 	void *addr;
658 
659 	/* split segment up heeding page boundaries */
660 	for (addr = start_addr, remaining = total_length; remaining > 0;
661 	     addr += length, remaining -= length) {
662 		/* get next free SBALE for new piece */
663 		if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
664 			/* no SBALE left, clean up and leave */
665 			zfcp_qdio_sbals_wipe(fsf_req);
666 			return -EINVAL;
667 		}
668 		/* calculate length of new piece */
669 		length = min(remaining,
670 			     (PAGE_SIZE - ((unsigned long) addr &
671 					   (PAGE_SIZE - 1))));
672 		/* fill current SBALE with calculated piece */
673 		zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
674 	}
675 	return total_length;
676 }
677 
678 
679 /**
680  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
681  * @fsf_req: request to be processed
682  * @sbtype: SBALE flags
683  * @sg: scatter-gather list
684  * @sg_count: number of elements in scatter-gather list
685  * @max_sbals: upper bound for number of SBALs to be used
686  */
687 inline int
688 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
689                         struct scatterlist *sg,	int sg_count, int max_sbals)
690 {
691 	int sg_index;
692 	struct scatterlist *sg_segment;
693 	int retval;
694 	volatile struct qdio_buffer_element *sbale;
695 	int bytes = 0;
696 
697 	/* figure out last allowed SBAL */
698 	zfcp_qdio_sbal_limit(fsf_req, max_sbals);
699 
700 	/* set storage-block type for current SBAL */
701 	sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
702 	sbale->flags |= sbtype;
703 
704 	/* process all segements of scatter-gather list */
705 	for (sg_index = 0, sg_segment = sg, bytes = 0;
706 	     sg_index < sg_count;
707 	     sg_index++, sg_segment++) {
708 		retval = zfcp_qdio_sbals_from_segment(
709 				fsf_req,
710 				sbtype,
711 				zfcp_sg_to_address(sg_segment),
712 				sg_segment->length);
713 		if (retval < 0) {
714 			bytes = retval;
715 			goto out;
716 		} else
717                         bytes += retval;
718 	}
719 	/* assume that no other SBALEs are to follow in the same SBAL */
720 	sbale = zfcp_qdio_sbale_curr(fsf_req);
721 	sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
722 out:
723 	return bytes;
724 }
725 
726 
727 /**
728  * zfcp_qdio_sbals_from_buffer - fill SBALs from buffer
729  * @fsf_req: request to be processed
730  * @sbtype: SBALE flags
731  * @buffer: data buffer
732  * @length: length of buffer
733  * @max_sbals: upper bound for number of SBALs to be used
734  */
735 static inline int
736 zfcp_qdio_sbals_from_buffer(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
737 			    void *buffer, unsigned long length, int max_sbals)
738 {
739 	struct scatterlist sg_segment;
740 
741 	zfcp_address_to_sg(buffer, &sg_segment);
742 	sg_segment.length = length;
743 
744 	return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, &sg_segment, 1,
745                                        max_sbals);
746 }
747 
748 
749 /**
750  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
751  * @fsf_req: request to be processed
752  * @sbtype: SBALE flags
753  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
754  *	to fill SBALs
755  */
756 inline int
757 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
758 			      unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
759 {
760 	if (scsi_cmnd->use_sg) {
761 		return zfcp_qdio_sbals_from_sg(fsf_req,	sbtype,
762                                                (struct scatterlist *)
763                                                scsi_cmnd->request_buffer,
764                                                scsi_cmnd->use_sg,
765                                                ZFCP_MAX_SBALS_PER_REQ);
766 	} else {
767                 return zfcp_qdio_sbals_from_buffer(fsf_req, sbtype,
768                                                    scsi_cmnd->request_buffer,
769                                                    scsi_cmnd->request_bufflen,
770                                                    ZFCP_MAX_SBALS_PER_REQ);
771 	}
772 }
773 
774 /**
775  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
776  */
777 int
778 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
779 			struct zfcp_fsf_req *fsf_req)
780 {
781 	int new_distance_from_int;
782 	int pci_pos;
783 	volatile struct qdio_buffer_element *sbale;
784 
785 	new_distance_from_int = req_queue->distance_from_int +
786                 fsf_req->sbal_number;
787 
788 	if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
789 		new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
790                 pci_pos  = fsf_req->sbal_first;
791 		pci_pos += fsf_req->sbal_number;
792 		pci_pos -= new_distance_from_int;
793 		pci_pos -= 1;
794 		pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
795 		sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
796 		sbale->flags |= SBAL_FLAGS0_PCI;
797 	}
798 	return new_distance_from_int;
799 }
800 
801 /*
802  * function:	zfcp_zero_sbals
803  *
804  * purpose:	zeros specified range of SBALs
805  *
806  * returns:
807  */
808 void
809 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
810 {
811 	int cur_pos;
812 	int index;
813 
814 	for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
815 		index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
816 		memset(buf[index], 0, sizeof (struct qdio_buffer));
817 		ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
818 			       index, buf[index]);
819 	}
820 }
821 
822 #undef ZFCP_LOG_AREA
823