Merge branches 'release', 'cpuidle-2.6.25' and 'idle' into release
[linux-2.6] / drivers / s390 / scsi / zfcp_qdio.c
1 /*
2  * This file is part of the zfcp device driver for
3  * FCP adapters for IBM System z9 and zSeries.
4  *
5  * (C) Copyright IBM Corp. 2002, 2006
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2, or (at your option)
10  * any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21
22 #include "zfcp_ext.h"
23
24 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *, int);
25 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_get
26         (struct zfcp_qdio_queue *, int, int);
27 static inline volatile struct qdio_buffer_element *zfcp_qdio_sbale_resp
28         (struct zfcp_fsf_req *, int, int);
29 static volatile struct qdio_buffer_element *zfcp_qdio_sbal_chain
30         (struct zfcp_fsf_req *, unsigned long);
31 static volatile struct qdio_buffer_element *zfcp_qdio_sbale_next
32         (struct zfcp_fsf_req *, unsigned long);
33 static int zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *, int, int);
34 static inline int zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *);
35 static void zfcp_qdio_sbale_fill
36         (struct zfcp_fsf_req *, unsigned long, void *, int);
37 static int zfcp_qdio_sbals_from_segment
38         (struct zfcp_fsf_req *, unsigned long, void *, unsigned long);
39
40 static qdio_handler_t zfcp_qdio_request_handler;
41 static qdio_handler_t zfcp_qdio_response_handler;
42 static int zfcp_qdio_handler_error_check(struct zfcp_adapter *,
43         unsigned int, unsigned int, unsigned int, int, int);
44
45 #define ZFCP_LOG_AREA                   ZFCP_LOG_AREA_QDIO
46
47 /*
48  * Frees BUFFER memory for each of the pointers of the struct qdio_buffer array
49  * in the adapter struct sbuf is the pointer array.
50  *
51  * locks:       must only be called with zfcp_data.config_sema taken
52  */
53 static void
54 zfcp_qdio_buffers_dequeue(struct qdio_buffer **sbuf)
55 {
56         int pos;
57
58         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE)
59                 free_page((unsigned long) sbuf[pos]);
60 }
61
62 /*
63  * Allocates BUFFER memory to each of the pointers of the qdio_buffer_t
64  * array in the adapter struct.
65  * Cur_buf is the pointer array
66  *
67  * returns:     zero on success else -ENOMEM
68  * locks:       must only be called with zfcp_data.config_sema taken
69  */
70 static int
71 zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbuf)
72 {
73         int pos;
74
75         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
76                 sbuf[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
77                 if (!sbuf[pos]) {
78                         zfcp_qdio_buffers_dequeue(sbuf);
79                         return -ENOMEM;
80                 }
81         }
82         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
83                 if (pos % QBUFF_PER_PAGE)
84                         sbuf[pos] = sbuf[pos - 1] + 1;
85         return 0;
86 }
87
88 /* locks:       must only be called with zfcp_data.config_sema taken */
89 int
90 zfcp_qdio_allocate_queues(struct zfcp_adapter *adapter)
91 {
92         int ret;
93
94         ret = zfcp_qdio_buffers_enqueue(adapter->request_queue.buffer);
95         if (ret)
96                 return ret;
97         return zfcp_qdio_buffers_enqueue(adapter->response_queue.buffer);
98 }
99
100 /* locks:       must only be called with zfcp_data.config_sema taken */
101 void
102 zfcp_qdio_free_queues(struct zfcp_adapter *adapter)
103 {
104         ZFCP_LOG_TRACE("freeing request_queue buffers\n");
105         zfcp_qdio_buffers_dequeue(adapter->request_queue.buffer);
106
107         ZFCP_LOG_TRACE("freeing response_queue buffers\n");
108         zfcp_qdio_buffers_dequeue(adapter->response_queue.buffer);
109 }
110
111 int
112 zfcp_qdio_allocate(struct zfcp_adapter *adapter)
113 {
114         struct qdio_initialize *init_data;
115
116         init_data = &adapter->qdio_init_data;
117
118         init_data->cdev = adapter->ccw_device;
119         init_data->q_format = QDIO_SCSI_QFMT;
120         memcpy(init_data->adapter_name, zfcp_get_busid_by_adapter(adapter), 8);
121         ASCEBC(init_data->adapter_name, 8);
122         init_data->qib_param_field_format = 0;
123         init_data->qib_param_field = NULL;
124         init_data->input_slib_elements = NULL;
125         init_data->output_slib_elements = NULL;
126         init_data->min_input_threshold = ZFCP_MIN_INPUT_THRESHOLD;
127         init_data->max_input_threshold = ZFCP_MAX_INPUT_THRESHOLD;
128         init_data->min_output_threshold = ZFCP_MIN_OUTPUT_THRESHOLD;
129         init_data->max_output_threshold = ZFCP_MAX_OUTPUT_THRESHOLD;
130         init_data->no_input_qs = 1;
131         init_data->no_output_qs = 1;
132         init_data->input_handler = zfcp_qdio_response_handler;
133         init_data->output_handler = zfcp_qdio_request_handler;
134         init_data->int_parm = (unsigned long) adapter;
135         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
136             QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
137         init_data->input_sbal_addr_array =
138             (void **) (adapter->response_queue.buffer);
139         init_data->output_sbal_addr_array =
140             (void **) (adapter->request_queue.buffer);
141
142         return qdio_allocate(init_data);
143 }
144
145 /*
146  * function:    zfcp_qdio_handler_error_check
147  *
148  * purpose:     called by the response handler to determine error condition
149  *
150  * returns:     error flag
151  *
152  */
153 static int
154 zfcp_qdio_handler_error_check(struct zfcp_adapter *adapter, unsigned int status,
155                               unsigned int qdio_error, unsigned int siga_error,
156                               int first_element, int elements_processed)
157 {
158         int retval = 0;
159
160         if (unlikely(status & QDIO_STATUS_LOOK_FOR_ERROR)) {
161                 retval = -EIO;
162
163                 ZFCP_LOG_INFO("QDIO problem occurred (status=0x%x, "
164                               "qdio_error=0x%x, siga_error=0x%x)\n",
165                               status, qdio_error, siga_error);
166
167                 zfcp_hba_dbf_event_qdio(adapter, status, qdio_error, siga_error,
168                                 first_element, elements_processed);
169                /*
170                 * Restarting IO on the failed adapter from scratch.
171                 * Since we have been using this adapter, it is save to assume
172                 * that it is not failed but recoverable. The card seems to
173                 * report link-up events by self-initiated queue shutdown.
174                 * That is why we need to clear the link-down flag
175                 * which is set again in case we have missed by a mile.
176                 */
177                 zfcp_erp_adapter_reopen(adapter,
178                                        ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
179                                        ZFCP_STATUS_COMMON_ERP_FAILED);
180         }
181         return retval;
182 }
183
184 /*
185  * function:    zfcp_qdio_request_handler
186  *
187  * purpose:     is called by QDIO layer for completed SBALs in request queue
188  *
189  * returns:     (void)
190  */
191 static void
192 zfcp_qdio_request_handler(struct ccw_device *ccw_device,
193                           unsigned int status,
194                           unsigned int qdio_error,
195                           unsigned int siga_error,
196                           unsigned int queue_number,
197                           int first_element,
198                           int elements_processed,
199                           unsigned long int_parm)
200 {
201         struct zfcp_adapter *adapter;
202         struct zfcp_qdio_queue *queue;
203
204         adapter = (struct zfcp_adapter *) int_parm;
205         queue = &adapter->request_queue;
206
207         ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
208                        zfcp_get_busid_by_adapter(adapter),
209                        first_element, elements_processed);
210
211         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
212                                                    siga_error, first_element,
213                                                    elements_processed)))
214                 goto out;
215         /*
216          * we stored address of struct zfcp_adapter  data structure
217          * associated with irq in int_parm
218          */
219
220         /* cleanup all SBALs being program-owned now */
221         zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
222
223         /* increase free space in outbound queue */
224         atomic_add(elements_processed, &queue->free_count);
225         ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
226         wake_up(&adapter->request_wq);
227         ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
228                        elements_processed, atomic_read(&queue->free_count));
229  out:
230         return;
231 }
232
233 /**
234  * zfcp_qdio_reqid_check - checks for valid reqids.
235  */
236 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
237                                   unsigned long req_id)
238 {
239         struct zfcp_fsf_req *fsf_req;
240         unsigned long flags;
241
242         debug_long_event(adapter->erp_dbf, 4, req_id);
243
244         spin_lock_irqsave(&adapter->req_list_lock, flags);
245         fsf_req = zfcp_reqlist_find(adapter, req_id);
246
247         if (!fsf_req)
248                 /*
249                  * Unknown request means that we have potentially memory
250                  * corruption and must stop the machine immediatly.
251                  */
252                 panic("error: unknown request id (%ld) on adapter %s.\n",
253                       req_id, zfcp_get_busid_by_adapter(adapter));
254
255         zfcp_reqlist_remove(adapter, fsf_req);
256         atomic_dec(&adapter->reqs_active);
257         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
258
259         /* finish the FSF request */
260         zfcp_fsf_req_complete(fsf_req);
261 }
262
263 /*
264  * function:    zfcp_qdio_response_handler
265  *
266  * purpose:     is called by QDIO layer for completed SBALs in response queue
267  *
268  * returns:     (void)
269  */
270 static void
271 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
272                            unsigned int status,
273                            unsigned int qdio_error,
274                            unsigned int siga_error,
275                            unsigned int queue_number,
276                            int first_element,
277                            int elements_processed,
278                            unsigned long int_parm)
279 {
280         struct zfcp_adapter *adapter;
281         struct zfcp_qdio_queue *queue;
282         int buffer_index;
283         int i;
284         struct qdio_buffer *buffer;
285         int retval = 0;
286         u8 count;
287         u8 start;
288         volatile struct qdio_buffer_element *buffere = NULL;
289         int buffere_index;
290
291         adapter = (struct zfcp_adapter *) int_parm;
292         queue = &adapter->response_queue;
293
294         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
295                                                    siga_error, first_element,
296                                                    elements_processed)))
297                 goto out;
298
299         /*
300          * we stored address of struct zfcp_adapter  data structure
301          * associated with irq in int_parm
302          */
303
304         buffere = &(queue->buffer[first_element]->element[0]);
305         ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
306         /*
307          * go through all SBALs from input queue currently
308          * returned by QDIO layer
309          */
310
311         for (i = 0; i < elements_processed; i++) {
312
313                 buffer_index = first_element + i;
314                 buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
315                 buffer = queue->buffer[buffer_index];
316
317                 /* go through all SBALEs of SBAL */
318                 for (buffere_index = 0;
319                      buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
320                      buffere_index++) {
321
322                         /* look for QDIO request identifiers in SB */
323                         buffere = &buffer->element[buffere_index];
324                         zfcp_qdio_reqid_check(adapter,
325                                               (unsigned long) buffere->addr);
326
327                         /*
328                          * A single used SBALE per inbound SBALE has been
329                          * implemented by QDIO so far. Hope they will
330                          * do some optimisation. Will need to change to
331                          * unlikely() then.
332                          */
333                         if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
334                                 break;
335                 };
336
337                 if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
338                         ZFCP_LOG_NORMAL("bug: End of inbound data "
339                                         "not marked!\n");
340                 }
341         }
342
343         /*
344          * put range of SBALs back to response queue
345          * (including SBALs which have already been free before)
346          */
347         count = atomic_read(&queue->free_count) + elements_processed;
348         start = queue->free_index;
349
350         ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
351                        "queue_no=%i, index_in_queue=%i, count=%i, "
352                        "buffers=0x%lx\n",
353                        zfcp_get_busid_by_adapter(adapter),
354                        QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
355                        0, start, count, (unsigned long) &queue->buffer[start]);
356
357         retval = do_QDIO(ccw_device,
358                          QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
359                          0, start, count, NULL);
360
361         if (unlikely(retval)) {
362                 atomic_set(&queue->free_count, count);
363                 ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
364                                "queues may be down "
365                                "(count=%d, start=%d, retval=%d)\n",
366                                count, start, retval);
367         } else {
368                 queue->free_index += count;
369                 queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
370                 atomic_set(&queue->free_count, 0);
371                 ZFCP_LOG_TRACE("%i buffers enqueued to response "
372                                "queue at position %i\n", count, start);
373         }
374  out:
375         return;
376 }
377
378 /**
379  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
380  * @queue: queue from which SBALE should be returned
381  * @sbal: specifies number of SBAL in queue
382  * @sbale: specifes number of SBALE in SBAL
383  */
384 static inline volatile struct qdio_buffer_element *
385 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
386 {
387         return &queue->buffer[sbal]->element[sbale];
388 }
389
390 /**
391  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
392  *      a struct zfcp_fsf_req
393  */
394 volatile struct qdio_buffer_element *
395 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
396 {
397         return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
398                                    sbal, sbale);
399 }
400
401 /**
402  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
403  *      a struct zfcp_fsf_req
404  */
405 static inline volatile struct qdio_buffer_element *
406 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
407 {
408         return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
409                                    sbal, sbale);
410 }
411
412 /**
413  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
414  *      a struct zfcp_fsf_req
415  */
416 volatile struct qdio_buffer_element *
417 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
418 {
419         return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
420                                    fsf_req->sbale_curr);
421 }
422
423 /**
424  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
425  *      on the request_queue for a struct zfcp_fsf_req
426  * @fsf_req: the number of the last SBAL that can be used is stored herein
427  * @max_sbals: used to pass an upper limit for the number of SBALs
428  *
429  * Note: We can assume at least one free SBAL in the request_queue when called.
430  */
431 static void
432 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
433 {
434         int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
435         count = min(count, max_sbals);
436         fsf_req->sbal_last  = fsf_req->sbal_first;
437         fsf_req->sbal_last += (count - 1);
438         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
439 }
440
441 /**
442  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
443  *      request
444  * @fsf_req: zfcp_fsf_req to be processed
445  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
446  *
447  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
448  */
449 static volatile struct qdio_buffer_element *
450 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
451 {
452         volatile struct qdio_buffer_element *sbale;
453
454         /* set last entry flag in current SBALE of current SBAL */
455         sbale = zfcp_qdio_sbale_curr(fsf_req);
456         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
457
458         /* don't exceed last allowed SBAL */
459         if (fsf_req->sbal_curr == fsf_req->sbal_last)
460                 return NULL;
461
462         /* set chaining flag in first SBALE of current SBAL */
463         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
464         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
465
466         /* calculate index of next SBAL */
467         fsf_req->sbal_curr++;
468         fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
469
470         /* keep this requests number of SBALs up-to-date */
471         fsf_req->sbal_number++;
472
473         /* start at first SBALE of new SBAL */
474         fsf_req->sbale_curr = 0;
475
476         /* set storage-block type for new SBAL */
477         sbale = zfcp_qdio_sbale_curr(fsf_req);
478         sbale->flags |= sbtype;
479
480         return sbale;
481 }
482
483 /**
484  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
485  */
486 static volatile struct qdio_buffer_element *
487 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
488 {
489         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
490                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
491
492         fsf_req->sbale_curr++;
493
494         return zfcp_qdio_sbale_curr(fsf_req);
495 }
496
497 /**
498  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
499  *      with zero from
500  */
501 static int
502 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
503 {
504         struct qdio_buffer **buf = queue->buffer;
505         int curr = first;
506         int count = 0;
507
508         for(;;) {
509                 curr %= QDIO_MAX_BUFFERS_PER_Q;
510                 count++;
511                 memset(buf[curr], 0, sizeof(struct qdio_buffer));
512                 if (curr == last)
513                         break;
514                 curr++;
515         }
516         return count;
517 }
518
519
520 /**
521  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
522  */
523 static inline int
524 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
525 {
526         return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
527                                     fsf_req->sbal_first, fsf_req->sbal_curr);
528 }
529
530
531 /**
532  * zfcp_qdio_sbale_fill - set address and length in current SBALE
533  *      on request_queue
534  */
535 static void
536 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
537                      void *addr, int length)
538 {
539         volatile struct qdio_buffer_element *sbale;
540
541         sbale = zfcp_qdio_sbale_curr(fsf_req);
542         sbale->addr = addr;
543         sbale->length = length;
544 }
545
546 /**
547  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
548  * @fsf_req: request to be processed
549  * @sbtype: SBALE flags
550  * @start_addr: address of memory segment
551  * @total_length: length of memory segment
552  *
553  * Alignment and length of the segment determine how many SBALEs are needed
554  * for the memory segment.
555  */
556 static int
557 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
558                              void *start_addr, unsigned long total_length)
559 {
560         unsigned long remaining, length;
561         void *addr;
562
563         /* split segment up heeding page boundaries */
564         for (addr = start_addr, remaining = total_length; remaining > 0;
565              addr += length, remaining -= length) {
566                 /* get next free SBALE for new piece */
567                 if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
568                         /* no SBALE left, clean up and leave */
569                         zfcp_qdio_sbals_wipe(fsf_req);
570                         return -EINVAL;
571                 }
572                 /* calculate length of new piece */
573                 length = min(remaining,
574                              (PAGE_SIZE - ((unsigned long) addr &
575                                            (PAGE_SIZE - 1))));
576                 /* fill current SBALE with calculated piece */
577                 zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
578         }
579         return total_length;
580 }
581
582
583 /**
584  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
585  * @fsf_req: request to be processed
586  * @sbtype: SBALE flags
587  * @sg: scatter-gather list
588  * @sg_count: number of elements in scatter-gather list
589  * @max_sbals: upper bound for number of SBALs to be used
590  */
591 int
592 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
593                         struct scatterlist *sgl, int sg_count, int max_sbals)
594 {
595         int sg_index;
596         struct scatterlist *sg_segment;
597         int retval;
598         volatile struct qdio_buffer_element *sbale;
599         int bytes = 0;
600
601         /* figure out last allowed SBAL */
602         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
603
604         /* set storage-block type for current SBAL */
605         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
606         sbale->flags |= sbtype;
607
608         /* process all segements of scatter-gather list */
609         for_each_sg(sgl, sg_segment, sg_count, sg_index) {
610                 retval = zfcp_qdio_sbals_from_segment(
611                                 fsf_req,
612                                 sbtype,
613                                 zfcp_sg_to_address(sg_segment),
614                                 sg_segment->length);
615                 if (retval < 0) {
616                         bytes = retval;
617                         goto out;
618                 } else
619                         bytes += retval;
620         }
621         /* assume that no other SBALEs are to follow in the same SBAL */
622         sbale = zfcp_qdio_sbale_curr(fsf_req);
623         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
624 out:
625         return bytes;
626 }
627
628
629 /**
630  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
631  * @fsf_req: request to be processed
632  * @sbtype: SBALE flags
633  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
634  *      to fill SBALs
635  */
636 int
637 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
638                               unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
639 {
640         return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, scsi_sglist(scsi_cmnd),
641                                        scsi_sg_count(scsi_cmnd),
642                                        ZFCP_MAX_SBALS_PER_REQ);
643 }
644
645 /**
646  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
647  */
648 int
649 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
650                         struct zfcp_fsf_req *fsf_req)
651 {
652         int new_distance_from_int;
653         int pci_pos;
654         volatile struct qdio_buffer_element *sbale;
655
656         new_distance_from_int = req_queue->distance_from_int +
657                 fsf_req->sbal_number;
658
659         if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
660                 new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
661                 pci_pos  = fsf_req->sbal_first;
662                 pci_pos += fsf_req->sbal_number;
663                 pci_pos -= new_distance_from_int;
664                 pci_pos -= 1;
665                 pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
666                 sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
667                 sbale->flags |= SBAL_FLAGS0_PCI;
668         }
669         return new_distance_from_int;
670 }
671
672 /*
673  * function:    zfcp_zero_sbals
674  *
675  * purpose:     zeros specified range of SBALs
676  *
677  * returns:
678  */
679 void
680 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
681 {
682         int cur_pos;
683         int index;
684
685         for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
686                 index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
687                 memset(buf[index], 0, sizeof (struct qdio_buffer));
688                 ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
689                                index, buf[index]);
690         }
691 }
692
693 #undef ZFCP_LOG_AREA