Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[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, 140,
180                                         NULL);
181         }
182         return retval;
183 }
184
185 /*
186  * function:    zfcp_qdio_request_handler
187  *
188  * purpose:     is called by QDIO layer for completed SBALs in request queue
189  *
190  * returns:     (void)
191  */
192 static void
193 zfcp_qdio_request_handler(struct ccw_device *ccw_device,
194                           unsigned int status,
195                           unsigned int qdio_error,
196                           unsigned int siga_error,
197                           unsigned int queue_number,
198                           int first_element,
199                           int elements_processed,
200                           unsigned long int_parm)
201 {
202         struct zfcp_adapter *adapter;
203         struct zfcp_qdio_queue *queue;
204
205         adapter = (struct zfcp_adapter *) int_parm;
206         queue = &adapter->request_queue;
207
208         ZFCP_LOG_DEBUG("adapter %s, first=%d, elements_processed=%d\n",
209                        zfcp_get_busid_by_adapter(adapter),
210                        first_element, elements_processed);
211
212         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
213                                                    siga_error, first_element,
214                                                    elements_processed)))
215                 goto out;
216         /*
217          * we stored address of struct zfcp_adapter  data structure
218          * associated with irq in int_parm
219          */
220
221         /* cleanup all SBALs being program-owned now */
222         zfcp_qdio_zero_sbals(queue->buffer, first_element, elements_processed);
223
224         /* increase free space in outbound queue */
225         atomic_add(elements_processed, &queue->free_count);
226         ZFCP_LOG_DEBUG("free_count=%d\n", atomic_read(&queue->free_count));
227         wake_up(&adapter->request_wq);
228         ZFCP_LOG_DEBUG("elements_processed=%d, free count=%d\n",
229                        elements_processed, atomic_read(&queue->free_count));
230  out:
231         return;
232 }
233
234 /**
235  * zfcp_qdio_reqid_check - checks for valid reqids.
236  */
237 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
238                                   unsigned long req_id)
239 {
240         struct zfcp_fsf_req *fsf_req;
241         unsigned long flags;
242
243         spin_lock_irqsave(&adapter->req_list_lock, flags);
244         fsf_req = zfcp_reqlist_find(adapter, req_id);
245
246         if (!fsf_req)
247                 /*
248                  * Unknown request means that we have potentially memory
249                  * corruption and must stop the machine immediatly.
250                  */
251                 panic("error: unknown request id (%ld) on adapter %s.\n",
252                       req_id, zfcp_get_busid_by_adapter(adapter));
253
254         zfcp_reqlist_remove(adapter, fsf_req);
255         atomic_dec(&adapter->reqs_active);
256         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
257
258         /* finish the FSF request */
259         zfcp_fsf_req_complete(fsf_req);
260 }
261
262 /*
263  * function:    zfcp_qdio_response_handler
264  *
265  * purpose:     is called by QDIO layer for completed SBALs in response queue
266  *
267  * returns:     (void)
268  */
269 static void
270 zfcp_qdio_response_handler(struct ccw_device *ccw_device,
271                            unsigned int status,
272                            unsigned int qdio_error,
273                            unsigned int siga_error,
274                            unsigned int queue_number,
275                            int first_element,
276                            int elements_processed,
277                            unsigned long int_parm)
278 {
279         struct zfcp_adapter *adapter;
280         struct zfcp_qdio_queue *queue;
281         int buffer_index;
282         int i;
283         struct qdio_buffer *buffer;
284         int retval = 0;
285         u8 count;
286         u8 start;
287         volatile struct qdio_buffer_element *buffere = NULL;
288         int buffere_index;
289
290         adapter = (struct zfcp_adapter *) int_parm;
291         queue = &adapter->response_queue;
292
293         if (unlikely(zfcp_qdio_handler_error_check(adapter, status, qdio_error,
294                                                    siga_error, first_element,
295                                                    elements_processed)))
296                 goto out;
297
298         /*
299          * we stored address of struct zfcp_adapter  data structure
300          * associated with irq in int_parm
301          */
302
303         buffere = &(queue->buffer[first_element]->element[0]);
304         ZFCP_LOG_DEBUG("first BUFFERE flags=0x%x\n", buffere->flags);
305         /*
306          * go through all SBALs from input queue currently
307          * returned by QDIO layer
308          */
309
310         for (i = 0; i < elements_processed; i++) {
311
312                 buffer_index = first_element + i;
313                 buffer_index %= QDIO_MAX_BUFFERS_PER_Q;
314                 buffer = queue->buffer[buffer_index];
315
316                 /* go through all SBALEs of SBAL */
317                 for (buffere_index = 0;
318                      buffere_index < QDIO_MAX_ELEMENTS_PER_BUFFER;
319                      buffere_index++) {
320
321                         /* look for QDIO request identifiers in SB */
322                         buffere = &buffer->element[buffere_index];
323                         zfcp_qdio_reqid_check(adapter,
324                                               (unsigned long) buffere->addr);
325
326                         /*
327                          * A single used SBALE per inbound SBALE has been
328                          * implemented by QDIO so far. Hope they will
329                          * do some optimisation. Will need to change to
330                          * unlikely() then.
331                          */
332                         if (likely(buffere->flags & SBAL_FLAGS_LAST_ENTRY))
333                                 break;
334                 };
335
336                 if (unlikely(!(buffere->flags & SBAL_FLAGS_LAST_ENTRY))) {
337                         ZFCP_LOG_NORMAL("bug: End of inbound data "
338                                         "not marked!\n");
339                 }
340         }
341
342         /*
343          * put range of SBALs back to response queue
344          * (including SBALs which have already been free before)
345          */
346         count = atomic_read(&queue->free_count) + elements_processed;
347         start = queue->free_index;
348
349         ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
350                        "queue_no=%i, index_in_queue=%i, count=%i, "
351                        "buffers=0x%lx\n",
352                        zfcp_get_busid_by_adapter(adapter),
353                        QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
354                        0, start, count, (unsigned long) &queue->buffer[start]);
355
356         retval = do_QDIO(ccw_device,
357                          QDIO_FLAG_SYNC_INPUT | QDIO_FLAG_UNDER_INTERRUPT,
358                          0, start, count, NULL);
359
360         if (unlikely(retval)) {
361                 atomic_set(&queue->free_count, count);
362                 ZFCP_LOG_DEBUG("clearing of inbound data regions failed, "
363                                "queues may be down "
364                                "(count=%d, start=%d, retval=%d)\n",
365                                count, start, retval);
366         } else {
367                 queue->free_index += count;
368                 queue->free_index %= QDIO_MAX_BUFFERS_PER_Q;
369                 atomic_set(&queue->free_count, 0);
370                 ZFCP_LOG_TRACE("%i buffers enqueued to response "
371                                "queue at position %i\n", count, start);
372         }
373  out:
374         return;
375 }
376
377 /**
378  * zfcp_qdio_sbale_get - return pointer to SBALE of qdio_queue
379  * @queue: queue from which SBALE should be returned
380  * @sbal: specifies number of SBAL in queue
381  * @sbale: specifes number of SBALE in SBAL
382  */
383 static inline volatile struct qdio_buffer_element *
384 zfcp_qdio_sbale_get(struct zfcp_qdio_queue *queue, int sbal, int sbale)
385 {
386         return &queue->buffer[sbal]->element[sbale];
387 }
388
389 /**
390  * zfcp_qdio_sbale_req - return pointer to SBALE of request_queue for
391  *      a struct zfcp_fsf_req
392  */
393 volatile struct qdio_buffer_element *
394 zfcp_qdio_sbale_req(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
395 {
396         return zfcp_qdio_sbale_get(&fsf_req->adapter->request_queue,
397                                    sbal, sbale);
398 }
399
400 /**
401  * zfcp_qdio_sbale_resp - return pointer to SBALE of response_queue for
402  *      a struct zfcp_fsf_req
403  */
404 static inline volatile struct qdio_buffer_element *
405 zfcp_qdio_sbale_resp(struct zfcp_fsf_req *fsf_req, int sbal, int sbale)
406 {
407         return zfcp_qdio_sbale_get(&fsf_req->adapter->response_queue,
408                                    sbal, sbale);
409 }
410
411 /**
412  * zfcp_qdio_sbale_curr - return current SBALE on request_queue for
413  *      a struct zfcp_fsf_req
414  */
415 volatile struct qdio_buffer_element *
416 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *fsf_req)
417 {
418         return zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr,
419                                    fsf_req->sbale_curr);
420 }
421
422 /**
423  * zfcp_qdio_sbal_limit - determine maximum number of SBALs that can be used
424  *      on the request_queue for a struct zfcp_fsf_req
425  * @fsf_req: the number of the last SBAL that can be used is stored herein
426  * @max_sbals: used to pass an upper limit for the number of SBALs
427  *
428  * Note: We can assume at least one free SBAL in the request_queue when called.
429  */
430 static void
431 zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
432 {
433         int count = atomic_read(&fsf_req->adapter->request_queue.free_count);
434         count = min(count, max_sbals);
435         fsf_req->sbal_last  = fsf_req->sbal_first;
436         fsf_req->sbal_last += (count - 1);
437         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
438 }
439
440 /**
441  * zfcp_qdio_sbal_chain - chain SBALs if more than one SBAL is needed for a
442  *      request
443  * @fsf_req: zfcp_fsf_req to be processed
444  * @sbtype: SBAL flags which have to be set in first SBALE of new SBAL
445  *
446  * This function changes sbal_curr, sbale_curr, sbal_number of fsf_req.
447  */
448 static volatile struct qdio_buffer_element *
449 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
450 {
451         volatile struct qdio_buffer_element *sbale;
452
453         /* set last entry flag in current SBALE of current SBAL */
454         sbale = zfcp_qdio_sbale_curr(fsf_req);
455         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
456
457         /* don't exceed last allowed SBAL */
458         if (fsf_req->sbal_curr == fsf_req->sbal_last)
459                 return NULL;
460
461         /* set chaining flag in first SBALE of current SBAL */
462         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
463         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
464
465         /* calculate index of next SBAL */
466         fsf_req->sbal_curr++;
467         fsf_req->sbal_curr %= QDIO_MAX_BUFFERS_PER_Q;
468
469         /* keep this requests number of SBALs up-to-date */
470         fsf_req->sbal_number++;
471
472         /* start at first SBALE of new SBAL */
473         fsf_req->sbale_curr = 0;
474
475         /* set storage-block type for new SBAL */
476         sbale = zfcp_qdio_sbale_curr(fsf_req);
477         sbale->flags |= sbtype;
478
479         return sbale;
480 }
481
482 /**
483  * zfcp_qdio_sbale_next - switch to next SBALE, chain SBALs if needed
484  */
485 static volatile struct qdio_buffer_element *
486 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
487 {
488         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
489                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
490
491         fsf_req->sbale_curr++;
492
493         return zfcp_qdio_sbale_curr(fsf_req);
494 }
495
496 /**
497  * zfcp_qdio_sbals_zero - initialize SBALs between first and last in queue
498  *      with zero from
499  */
500 static int
501 zfcp_qdio_sbals_zero(struct zfcp_qdio_queue *queue, int first, int last)
502 {
503         struct qdio_buffer **buf = queue->buffer;
504         int curr = first;
505         int count = 0;
506
507         for(;;) {
508                 curr %= QDIO_MAX_BUFFERS_PER_Q;
509                 count++;
510                 memset(buf[curr], 0, sizeof(struct qdio_buffer));
511                 if (curr == last)
512                         break;
513                 curr++;
514         }
515         return count;
516 }
517
518
519 /**
520  * zfcp_qdio_sbals_wipe - reset all changes in SBALs for an fsf_req
521  */
522 static inline int
523 zfcp_qdio_sbals_wipe(struct zfcp_fsf_req *fsf_req)
524 {
525         return zfcp_qdio_sbals_zero(&fsf_req->adapter->request_queue,
526                                     fsf_req->sbal_first, fsf_req->sbal_curr);
527 }
528
529
530 /**
531  * zfcp_qdio_sbale_fill - set address and length in current SBALE
532  *      on request_queue
533  */
534 static void
535 zfcp_qdio_sbale_fill(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
536                      void *addr, int length)
537 {
538         volatile struct qdio_buffer_element *sbale;
539
540         sbale = zfcp_qdio_sbale_curr(fsf_req);
541         sbale->addr = addr;
542         sbale->length = length;
543 }
544
545 /**
546  * zfcp_qdio_sbals_from_segment - map memory segment to SBALE(s)
547  * @fsf_req: request to be processed
548  * @sbtype: SBALE flags
549  * @start_addr: address of memory segment
550  * @total_length: length of memory segment
551  *
552  * Alignment and length of the segment determine how many SBALEs are needed
553  * for the memory segment.
554  */
555 static int
556 zfcp_qdio_sbals_from_segment(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
557                              void *start_addr, unsigned long total_length)
558 {
559         unsigned long remaining, length;
560         void *addr;
561
562         /* split segment up heeding page boundaries */
563         for (addr = start_addr, remaining = total_length; remaining > 0;
564              addr += length, remaining -= length) {
565                 /* get next free SBALE for new piece */
566                 if (NULL == zfcp_qdio_sbale_next(fsf_req, sbtype)) {
567                         /* no SBALE left, clean up and leave */
568                         zfcp_qdio_sbals_wipe(fsf_req);
569                         return -EINVAL;
570                 }
571                 /* calculate length of new piece */
572                 length = min(remaining,
573                              (PAGE_SIZE - ((unsigned long) addr &
574                                            (PAGE_SIZE - 1))));
575                 /* fill current SBALE with calculated piece */
576                 zfcp_qdio_sbale_fill(fsf_req, sbtype, addr, length);
577         }
578         return total_length;
579 }
580
581
582 /**
583  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
584  * @fsf_req: request to be processed
585  * @sbtype: SBALE flags
586  * @sg: scatter-gather list
587  * @sg_count: number of elements in scatter-gather list
588  * @max_sbals: upper bound for number of SBALs to be used
589  */
590 int
591 zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
592                         struct scatterlist *sgl, int sg_count, int max_sbals)
593 {
594         int sg_index;
595         struct scatterlist *sg_segment;
596         int retval;
597         volatile struct qdio_buffer_element *sbale;
598         int bytes = 0;
599
600         /* figure out last allowed SBAL */
601         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
602
603         /* set storage-block type for current SBAL */
604         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
605         sbale->flags |= sbtype;
606
607         /* process all segements of scatter-gather list */
608         for_each_sg(sgl, sg_segment, sg_count, sg_index) {
609                 retval = zfcp_qdio_sbals_from_segment(
610                                 fsf_req,
611                                 sbtype,
612                                 zfcp_sg_to_address(sg_segment),
613                                 sg_segment->length);
614                 if (retval < 0) {
615                         bytes = retval;
616                         goto out;
617                 } else
618                         bytes += retval;
619         }
620         /* assume that no other SBALEs are to follow in the same SBAL */
621         sbale = zfcp_qdio_sbale_curr(fsf_req);
622         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
623 out:
624         return bytes;
625 }
626
627
628 /**
629  * zfcp_qdio_sbals_from_scsicmnd - fill SBALs from scsi command
630  * @fsf_req: request to be processed
631  * @sbtype: SBALE flags
632  * @scsi_cmnd: either scatter-gather list or buffer contained herein is used
633  *      to fill SBALs
634  */
635 int
636 zfcp_qdio_sbals_from_scsicmnd(struct zfcp_fsf_req *fsf_req,
637                               unsigned long sbtype, struct scsi_cmnd *scsi_cmnd)
638 {
639         return zfcp_qdio_sbals_from_sg(fsf_req, sbtype, scsi_sglist(scsi_cmnd),
640                                        scsi_sg_count(scsi_cmnd),
641                                        ZFCP_MAX_SBALS_PER_REQ);
642 }
643
644 /**
645  * zfcp_qdio_determine_pci - set PCI flag in first SBALE on qdio queue if needed
646  */
647 int
648 zfcp_qdio_determine_pci(struct zfcp_qdio_queue *req_queue,
649                         struct zfcp_fsf_req *fsf_req)
650 {
651         int new_distance_from_int;
652         int pci_pos;
653         volatile struct qdio_buffer_element *sbale;
654
655         new_distance_from_int = req_queue->distance_from_int +
656                 fsf_req->sbal_number;
657
658         if (unlikely(new_distance_from_int >= ZFCP_QDIO_PCI_INTERVAL)) {
659                 new_distance_from_int %= ZFCP_QDIO_PCI_INTERVAL;
660                 pci_pos  = fsf_req->sbal_first;
661                 pci_pos += fsf_req->sbal_number;
662                 pci_pos -= new_distance_from_int;
663                 pci_pos -= 1;
664                 pci_pos %= QDIO_MAX_BUFFERS_PER_Q;
665                 sbale = zfcp_qdio_sbale_req(fsf_req, pci_pos, 0);
666                 sbale->flags |= SBAL_FLAGS0_PCI;
667         }
668         return new_distance_from_int;
669 }
670
671 /*
672  * function:    zfcp_zero_sbals
673  *
674  * purpose:     zeros specified range of SBALs
675  *
676  * returns:
677  */
678 void
679 zfcp_qdio_zero_sbals(struct qdio_buffer *buf[], int first, int clean_count)
680 {
681         int cur_pos;
682         int index;
683
684         for (cur_pos = first; cur_pos < (first + clean_count); cur_pos++) {
685                 index = cur_pos % QDIO_MAX_BUFFERS_PER_Q;
686                 memset(buf[index], 0, sizeof (struct qdio_buffer));
687                 ZFCP_LOG_TRACE("zeroing BUFFER %d at address %p\n",
688                                index, buf[index]);
689         }
690 }
691
692 #undef ZFCP_LOG_AREA