xref: /openbmc/linux/drivers/s390/scsi/zfcp_qdio.c (revision 545e4006)
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(&req_q->lock);
427 	atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
428 	spin_unlock(&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 }
496