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