Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6] / drivers / s390 / scsi / zfcp_qdio.c
1 /*
2  * zfcp device driver
3  *
4  * Setup and helper functions to access QDIO.
5  *
6  * Copyright IBM Corporation 2002, 2008
7  */
8
9 #include "zfcp_ext.h"
10
11 /* FIXME(tune): free space should be one max. SBAL chain plus what? */
12 #define ZFCP_QDIO_PCI_INTERVAL  (QDIO_MAX_BUFFERS_PER_Q \
13                                 - (FSF_MAX_SBALS_PER_REQ + 4))
14 #define QBUFF_PER_PAGE          (PAGE_SIZE / sizeof(struct qdio_buffer))
15
16 static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
17 {
18         int pos;
19
20         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
21                 sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
22                 if (!sbal[pos])
23                         return -ENOMEM;
24         }
25         for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
26                 if (pos % QBUFF_PER_PAGE)
27                         sbal[pos] = sbal[pos - 1] + 1;
28         return 0;
29 }
30
31 static volatile struct qdio_buffer_element *
32 zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
33 {
34         return &q->sbal[sbal_idx]->element[sbale_idx];
35 }
36
37 /**
38  * zfcp_qdio_free - free memory used by request- and resposne queue
39  * @adapter: pointer to the zfcp_adapter structure
40  */
41 void zfcp_qdio_free(struct zfcp_adapter *adapter)
42 {
43         struct qdio_buffer **sbal_req, **sbal_resp;
44         int p;
45
46         if (adapter->ccw_device)
47                 qdio_free(adapter->ccw_device);
48
49         sbal_req = adapter->req_q.sbal;
50         sbal_resp = adapter->resp_q.sbal;
51
52         for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
53                 free_page((unsigned long) sbal_req[p]);
54                 free_page((unsigned long) sbal_resp[p]);
55         }
56 }
57
58 static void zfcp_qdio_handler_error(struct zfcp_adapter *adapter, u8 id)
59 {
60         dev_warn(&adapter->ccw_device->dev, "QDIO problem occurred.\n");
61
62         zfcp_erp_adapter_reopen(adapter,
63                                 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
64                                 ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
65 }
66
67 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
68 {
69         int i, sbal_idx;
70
71         for (i = first; i < first + cnt; i++) {
72                 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
73                 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
74         }
75 }
76
77 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
78                               int queue_no, int first, int count,
79                               unsigned long parm)
80 {
81         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
82         struct zfcp_qdio_queue *queue = &adapter->req_q;
83
84         if (unlikely(qdio_err)) {
85                 zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
86                 zfcp_qdio_handler_error(adapter, 140);
87                 return;
88         }
89
90         /* cleanup all SBALs being program-owned now */
91         zfcp_qdio_zero_sbals(queue->sbal, first, count);
92
93         atomic_add(count, &queue->count);
94         wake_up(&adapter->request_wq);
95 }
96
97 static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
98                                   unsigned long req_id, int sbal_idx)
99 {
100         struct zfcp_fsf_req *fsf_req;
101         unsigned long flags;
102
103         spin_lock_irqsave(&adapter->req_list_lock, flags);
104         fsf_req = zfcp_reqlist_find(adapter, req_id);
105
106         if (!fsf_req)
107                 /*
108                  * Unknown request means that we have potentially memory
109                  * corruption and must stop the machine immediatly.
110                  */
111                 panic("error: unknown request id (%lx) on adapter %s.\n",
112                       req_id, zfcp_get_busid_by_adapter(adapter));
113
114         zfcp_reqlist_remove(adapter, fsf_req);
115         spin_unlock_irqrestore(&adapter->req_list_lock, flags);
116
117         fsf_req->sbal_response = sbal_idx;
118         zfcp_fsf_req_complete(fsf_req);
119 }
120
121 static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
122 {
123         struct zfcp_qdio_queue *queue = &adapter->resp_q;
124         struct ccw_device *cdev = adapter->ccw_device;
125         u8 count, start = queue->first;
126         unsigned int retval;
127
128         count = atomic_read(&queue->count) + processed;
129
130         retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);
131
132         if (unlikely(retval)) {
133                 atomic_set(&queue->count, count);
134                 /* FIXME: Recover this with an adapter reopen? */
135         } else {
136                 queue->first += count;
137                 queue->first %= QDIO_MAX_BUFFERS_PER_Q;
138                 atomic_set(&queue->count, 0);
139         }
140 }
141
142 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
143                                int queue_no, int first, int count,
144                                unsigned long parm)
145 {
146         struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
147         struct zfcp_qdio_queue *queue = &adapter->resp_q;
148         volatile struct qdio_buffer_element *sbale;
149         int sbal_idx, sbale_idx, sbal_no;
150
151         if (unlikely(qdio_err)) {
152                 zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
153                 zfcp_qdio_handler_error(adapter, 147);
154                 return;
155         }
156
157         /*
158          * go through all SBALs from input queue currently
159          * returned by QDIO layer
160          */
161         for (sbal_no = 0; sbal_no < count; sbal_no++) {
162                 sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
163
164                 /* go through all SBALEs of SBAL */
165                 for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
166                      sbale_idx++) {
167                         sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
168                         zfcp_qdio_reqid_check(adapter,
169                                               (unsigned long) sbale->addr,
170                                               sbal_idx);
171                         if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
172                                 break;
173                 };
174
175                 if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
176                         dev_warn(&adapter->ccw_device->dev,
177                                  "Protocol violation by adapter. "
178                                  "Continuing operations.\n");
179         }
180
181         /*
182          * put range of SBALs back to response queue
183          * (including SBALs which have already been free before)
184          */
185         zfcp_qdio_resp_put_back(adapter, count);
186 }
187
188 /**
189  * zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
190  * @fsf_req: pointer to struct fsf_req
191  * Returns: pointer to qdio_buffer_element (SBALE) structure
192  */
193 volatile struct qdio_buffer_element *
194 zfcp_qdio_sbale_req(struct zfcp_fsf_req *req)
195 {
196         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
197 }
198
199 /**
200  * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
201  * @fsf_req: pointer to struct fsf_req
202  * Returns: pointer to qdio_buffer_element (SBALE) structure
203  */
204 volatile struct qdio_buffer_element *
205 zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
206 {
207         return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
208                                req->sbale_curr);
209 }
210
211 static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
212 {
213         int count = atomic_read(&fsf_req->adapter->req_q.count);
214         count = min(count, max_sbals);
215         fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
216                                         % QDIO_MAX_BUFFERS_PER_Q;
217 }
218
219 static volatile struct qdio_buffer_element *
220 zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
221 {
222         volatile struct qdio_buffer_element *sbale;
223
224         /* set last entry flag in current SBALE of current SBAL */
225         sbale = zfcp_qdio_sbale_curr(fsf_req);
226         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
227
228         /* don't exceed last allowed SBAL */
229         if (fsf_req->sbal_last == fsf_req->sbal_limit)
230                 return NULL;
231
232         /* set chaining flag in first SBALE of current SBAL */
233         sbale = zfcp_qdio_sbale_req(fsf_req);
234         sbale->flags |= SBAL_FLAGS0_MORE_SBALS;
235
236         /* calculate index of next SBAL */
237         fsf_req->sbal_last++;
238         fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
239
240         /* keep this requests number of SBALs up-to-date */
241         fsf_req->sbal_number++;
242
243         /* start at first SBALE of new SBAL */
244         fsf_req->sbale_curr = 0;
245
246         /* set storage-block type for new SBAL */
247         sbale = zfcp_qdio_sbale_curr(fsf_req);
248         sbale->flags |= sbtype;
249
250         return sbale;
251 }
252
253 static volatile struct qdio_buffer_element *
254 zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
255 {
256         if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
257                 return zfcp_qdio_sbal_chain(fsf_req, sbtype);
258         fsf_req->sbale_curr++;
259         return zfcp_qdio_sbale_curr(fsf_req);
260 }
261
262 static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
263 {
264         struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
265         int first = fsf_req->sbal_first;
266         int last = fsf_req->sbal_last;
267         int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
268                 QDIO_MAX_BUFFERS_PER_Q + 1;
269         zfcp_qdio_zero_sbals(sbal, first, count);
270 }
271
272 static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
273                                 unsigned int sbtype, void *start_addr,
274                                 unsigned int total_length)
275 {
276         volatile struct qdio_buffer_element *sbale;
277         unsigned long remaining, length;
278         void *addr;
279
280         /* split segment up */
281         for (addr = start_addr, remaining = total_length; remaining > 0;
282              addr += length, remaining -= length) {
283                 sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
284                 if (!sbale) {
285                         zfcp_qdio_undo_sbals(fsf_req);
286                         return -EINVAL;
287                 }
288
289                 /* new piece must not exceed next page boundary */
290                 length = min(remaining,
291                              (PAGE_SIZE - ((unsigned long)addr &
292                                            (PAGE_SIZE - 1))));
293                 sbale->addr = addr;
294                 sbale->length = length;
295         }
296         return 0;
297 }
298
299 /**
300  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
301  * @fsf_req: request to be processed
302  * @sbtype: SBALE flags
303  * @sg: scatter-gather list
304  * @max_sbals: upper bound for number of SBALs to be used
305  * Returns: number of bytes, or error (negativ)
306  */
307 int zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
308                             struct scatterlist *sg, int max_sbals)
309 {
310         volatile struct qdio_buffer_element *sbale;
311         int retval, bytes = 0;
312
313         /* figure out last allowed SBAL */
314         zfcp_qdio_sbal_limit(fsf_req, max_sbals);
315
316         /* set storage-block type for this request */
317         sbale = zfcp_qdio_sbale_req(fsf_req);
318         sbale->flags |= sbtype;
319
320         for (; sg; sg = sg_next(sg)) {
321                 retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
322                                               sg->length);
323                 if (retval < 0)
324                         return retval;
325                 bytes += sg->length;
326         }
327
328         /* assume that no other SBALEs are to follow in the same SBAL */
329         sbale = zfcp_qdio_sbale_curr(fsf_req);
330         sbale->flags |= SBAL_FLAGS_LAST_ENTRY;
331
332         return bytes;
333 }
334
335 /**
336  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
337  * @fsf_req: pointer to struct zfcp_fsf_req
338  * Returns: 0 on success, error otherwise
339  */
340 int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
341 {
342         struct zfcp_adapter *adapter = fsf_req->adapter;
343         struct zfcp_qdio_queue *req_q = &adapter->req_q;
344         int first = fsf_req->sbal_first;
345         int count = fsf_req->sbal_number;
346         int retval, pci, pci_batch;
347         volatile struct qdio_buffer_element *sbale;
348
349         /* acknowledgements for transferred buffers */
350         pci_batch = req_q->pci_batch + count;
351         if (unlikely(pci_batch >= ZFCP_QDIO_PCI_INTERVAL)) {
352                 pci_batch %= ZFCP_QDIO_PCI_INTERVAL;
353                 pci = first + count - (pci_batch + 1);
354                 pci %= QDIO_MAX_BUFFERS_PER_Q;
355                 sbale = zfcp_qdio_sbale(req_q, pci, 0);
356                 sbale->flags |= SBAL_FLAGS0_PCI;
357         }
358
359         retval = do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0, first,
360                          count);
361         if (unlikely(retval)) {
362                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
363                 return retval;
364         }
365
366         /* account for transferred buffers */
367         atomic_sub(count, &req_q->count);
368         req_q->first += count;
369         req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
370         req_q->pci_batch = pci_batch;
371         return 0;
372 }
373
374 /**
375  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
376  * @adapter: pointer to struct zfcp_adapter
377  * Returns: -ENOMEM on memory allocation error or return value from
378  *          qdio_allocate
379  */
380 int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
381 {
382         struct qdio_initialize *init_data;
383
384         if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
385                    zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
386                 return -ENOMEM;
387
388         init_data = &adapter->qdio_init_data;
389
390         init_data->cdev = adapter->ccw_device;
391         init_data->q_format = QDIO_ZFCP_QFMT;
392         memcpy(init_data->adapter_name, zfcp_get_busid_by_adapter(adapter), 8);
393         ASCEBC(init_data->adapter_name, 8);
394         init_data->qib_param_field_format = 0;
395         init_data->qib_param_field = NULL;
396         init_data->input_slib_elements = NULL;
397         init_data->output_slib_elements = NULL;
398         init_data->no_input_qs = 1;
399         init_data->no_output_qs = 1;
400         init_data->input_handler = zfcp_qdio_int_resp;
401         init_data->output_handler = zfcp_qdio_int_req;
402         init_data->int_parm = (unsigned long) adapter;
403         init_data->flags = QDIO_INBOUND_0COPY_SBALS |
404                         QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
405         init_data->input_sbal_addr_array =
406                         (void **) (adapter->resp_q.sbal);
407         init_data->output_sbal_addr_array =
408                         (void **) (adapter->req_q.sbal);
409
410         return qdio_allocate(init_data);
411 }
412
413 /**
414  * zfcp_close_qdio - close qdio queues for an adapter
415  */
416 void zfcp_qdio_close(struct zfcp_adapter *adapter)
417 {
418         struct zfcp_qdio_queue *req_q;
419         int first, count;
420
421         if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status))
422                 return;
423
424         /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
425         req_q = &adapter->req_q;
426         spin_lock_bh(&req_q->lock);
427         atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
428         spin_unlock_bh(&req_q->lock);
429
430         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
431
432         /* cleanup used outbound sbals */
433         count = atomic_read(&req_q->count);
434         if (count < QDIO_MAX_BUFFERS_PER_Q) {
435                 first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
436                 count = QDIO_MAX_BUFFERS_PER_Q - count;
437                 zfcp_qdio_zero_sbals(req_q->sbal, first, count);
438         }
439         req_q->first = 0;
440         atomic_set(&req_q->count, 0);
441         req_q->pci_batch = 0;
442         adapter->resp_q.first = 0;
443         atomic_set(&adapter->resp_q.count, 0);
444 }
445
446 /**
447  * zfcp_qdio_open - prepare and initialize response queue
448  * @adapter: pointer to struct zfcp_adapter
449  * Returns: 0 on success, otherwise -EIO
450  */
451 int zfcp_qdio_open(struct zfcp_adapter *adapter)
452 {
453         volatile struct qdio_buffer_element *sbale;
454         int cc;
455
456         if (atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status))
457                 return -EIO;
458
459         if (qdio_establish(&adapter->qdio_init_data)) {
460                 dev_err(&adapter->ccw_device->dev,
461                          "Establish of QDIO queues failed.\n");
462                 return -EIO;
463         }
464
465         if (qdio_activate(adapter->ccw_device)) {
466                 dev_err(&adapter->ccw_device->dev,
467                          "Activate of QDIO queues failed.\n");
468                 goto failed_qdio;
469         }
470
471         for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
472                 sbale = &(adapter->resp_q.sbal[cc]->element[0]);
473                 sbale->length = 0;
474                 sbale->flags = SBAL_FLAGS_LAST_ENTRY;
475                 sbale->addr = NULL;
476         }
477
478         if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
479                      QDIO_MAX_BUFFERS_PER_Q)) {
480                 dev_err(&adapter->ccw_device->dev,
481                          "Init of QDIO response queue failed.\n");
482                 goto failed_qdio;
483         }
484
485         /* set index of first avalable SBALS / number of available SBALS */
486         adapter->req_q.first = 0;
487         atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
488         adapter->req_q.pci_batch = 0;
489
490         return 0;
491
492 failed_qdio:
493         qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
494         return -EIO;
495 }