summaryrefslogtreecommitdiffstats
path: root/drivers/s390/scsi/zfcp_qdio.c
blob: 3d0687090274e5d18d31aeedbb751c25aff9d71a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
/*
 * zfcp device driver
 *
 * Setup and helper functions to access QDIO.
 *
 * Copyright IBM Corporation 2002, 2008
 */

#define KMSG_COMPONENT "zfcp"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include "zfcp_ext.h"

/* FIXME(tune): free space should be one max. SBAL chain plus what? */
#define ZFCP_QDIO_PCI_INTERVAL	(QDIO_MAX_BUFFERS_PER_Q \
				- (FSF_MAX_SBALS_PER_REQ + 4))
#define QBUFF_PER_PAGE		(PAGE_SIZE / sizeof(struct qdio_buffer))

static int zfcp_qdio_buffers_enqueue(struct qdio_buffer **sbal)
{
	int pos;

	for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos += QBUFF_PER_PAGE) {
		sbal[pos] = (struct qdio_buffer *) get_zeroed_page(GFP_KERNEL);
		if (!sbal[pos])
			return -ENOMEM;
	}
	for (pos = 0; pos < QDIO_MAX_BUFFERS_PER_Q; pos++)
		if (pos % QBUFF_PER_PAGE)
			sbal[pos] = sbal[pos - 1] + 1;
	return 0;
}

static struct qdio_buffer_element *
zfcp_qdio_sbale(struct zfcp_qdio_queue *q, int sbal_idx, int sbale_idx)
{
	return &q->sbal[sbal_idx]->element[sbale_idx];
}

/**
 * zfcp_qdio_free - free memory used by request- and resposne queue
 * @adapter: pointer to the zfcp_adapter structure
 */
void zfcp_qdio_free(struct zfcp_adapter *adapter)
{
	struct qdio_buffer **sbal_req, **sbal_resp;
	int p;

	if (adapter->ccw_device)
		qdio_free(adapter->ccw_device);

	sbal_req = adapter->req_q.sbal;
	sbal_resp = adapter->resp_q.sbal;

	for (p = 0; p < QDIO_MAX_BUFFERS_PER_Q; p += QBUFF_PER_PAGE) {
		free_page((unsigned long) sbal_req[p]);
		free_page((unsigned long) sbal_resp[p]);
	}
}

static void zfcp_qdio_handler_error(struct zfcp_adapter *adapter, u8 id)
{
	dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");

	zfcp_erp_adapter_reopen(adapter,
				ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
				ZFCP_STATUS_COMMON_ERP_FAILED, id, NULL);
}

static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
{
	int i, sbal_idx;

	for (i = first; i < first + cnt; i++) {
		sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
		memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
	}
}

/* this needs to be called prior to updating the queue fill level */
static void zfcp_qdio_account(struct zfcp_adapter *adapter)
{
	ktime_t now;
	s64 span;
	int free, used;

	spin_lock(&adapter->qdio_stat_lock);
	now = ktime_get();
	span = ktime_us_delta(now, adapter->req_q_time);
	free = max(0, atomic_read(&adapter->req_q.count));
	used = QDIO_MAX_BUFFERS_PER_Q - free;
	adapter->req_q_util += used * span;
	adapter->req_q_time = now;
	spin_unlock(&adapter->qdio_stat_lock);
}

static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
			      int queue_no, int first, int count,
			      unsigned long parm)
{
	struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
	struct zfcp_qdio_queue *queue = &adapter->req_q;

	if (unlikely(qdio_err)) {
		zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
		zfcp_qdio_handler_error(adapter, 140);
		return;
	}

	/* cleanup all SBALs being program-owned now */
	zfcp_qdio_zero_sbals(queue->sbal, first, count);

	zfcp_qdio_account(adapter);
	atomic_add(count, &queue->count);
	wake_up(&adapter->request_wq);
}

static void zfcp_qdio_reqid_check(struct zfcp_adapter *adapter,
				  unsigned long req_id, int sbal_idx)
{
	struct zfcp_fsf_req *fsf_req;
	unsigned long flags;

	spin_lock_irqsave(&adapter->req_list_lock, flags);
	fsf_req = zfcp_reqlist_find(adapter, req_id);

	if (!fsf_req)
		/*
		 * Unknown request means that we have potentially memory
		 * corruption and must stop the machine immediatly.
		 */
		panic("error: unknown request id (%lx) on adapter %s.\n",
		      req_id, dev_name(&adapter->ccw_device->dev));

	zfcp_reqlist_remove(adapter, fsf_req);
	spin_unlock_irqrestore(&adapter->req_list_lock, flags);

	fsf_req->sbal_response = sbal_idx;
	fsf_req->qdio_inb_usage = atomic_read(&adapter->resp_q.count);
	zfcp_fsf_req_complete(fsf_req);
}

static void zfcp_qdio_resp_put_back(struct zfcp_adapter *adapter, int processed)
{
	struct zfcp_qdio_queue *queue = &adapter->resp_q;
	struct ccw_device *cdev = adapter->ccw_device;
	u8 count, start = queue->first;
	unsigned int retval;

	count = atomic_read(&queue->count) + processed;

	retval = do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, start, count);

	if (unlikely(retval)) {
		atomic_set(&queue->count, count);
		/* FIXME: Recover this with an adapter reopen? */
	} else {
		queue->first += count;
		queue->first %= QDIO_MAX_BUFFERS_PER_Q;
		atomic_set(&queue->count, 0);
	}
}

static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
			       int queue_no, int first, int count,
			       unsigned long parm)
{
	struct zfcp_adapter *adapter = (struct zfcp_adapter *) parm;
	struct zfcp_qdio_queue *queue = &adapter->resp_q;
	struct qdio_buffer_element *sbale;
	int sbal_idx, sbale_idx, sbal_no;

	if (unlikely(qdio_err)) {
		zfcp_hba_dbf_event_qdio(adapter, qdio_err, first, count);
		zfcp_qdio_handler_error(adapter, 147);
		return;
	}

	/*
	 * go through all SBALs from input queue currently
	 * returned by QDIO layer
	 */
	for (sbal_no = 0; sbal_no < count; sbal_no++) {
		sbal_idx = (first + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;

		/* go through all SBALEs of SBAL */
		for (sbale_idx = 0; sbale_idx < QDIO_MAX_ELEMENTS_PER_BUFFER;
		     sbale_idx++) {
			sbale = zfcp_qdio_sbale(queue, sbal_idx, sbale_idx);
			zfcp_qdio_reqid_check(adapter,
					      (unsigned long) sbale->addr,
					      sbal_idx);
			if (likely(sbale->flags & SBAL_FLAGS_LAST_ENTRY))
				break;
		};

		if (unlikely(!(sbale->flags & SBAL_FLAGS_LAST_ENTRY)))
			dev_warn(&adapter->ccw_device->dev,
				 "A QDIO protocol error occurred, "
				 "operations continue\n");
	}

	/*
	 * put range of SBALs back to response queue
	 * (including SBALs which have already been free before)
	 */
	zfcp_qdio_resp_put_back(adapter, count);
}

/**
 * zfcp_qdio_sbale_req - return ptr to SBALE of req_q for a struct zfcp_fsf_req
 * @fsf_req: pointer to struct fsf_req
 * Returns: pointer to qdio_buffer_element (SBALE) structure
 */
struct qdio_buffer_element *zfcp_qdio_sbale_req(struct zfcp_fsf_req *req)
{
	return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last, 0);
}

/**
 * zfcp_qdio_sbale_curr - return curr SBALE on req_q for a struct zfcp_fsf_req
 * @fsf_req: pointer to struct fsf_req
 * Returns: pointer to qdio_buffer_element (SBALE) structure
 */
struct qdio_buffer_element *zfcp_qdio_sbale_curr(struct zfcp_fsf_req *req)
{
	return zfcp_qdio_sbale(&req->adapter->req_q, req->sbal_last,
			       req->sbale_curr);
}

static void zfcp_qdio_sbal_limit(struct zfcp_fsf_req *fsf_req, int max_sbals)
{
	int count = atomic_read(&fsf_req->adapter->req_q.count);
	count = min(count, max_sbals);
	fsf_req->sbal_limit = (fsf_req->sbal_first + count - 1)
					% QDIO_MAX_BUFFERS_PER_Q;
}

static struct qdio_buffer_element *
zfcp_qdio_sbal_chain(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
{
	struct qdio_buffer_element *sbale;

	/* set last entry flag in current SBALE of current SBAL */
	sbale = zfcp_qdio_sbale_curr(fsf_req);
	sbale->flags |= SBAL_FLAGS_LAST_ENTRY;

	/* don't exceed last allowed SBAL */
	if (fsf_req->sbal_last == fsf_req->sbal_limit)
		return NULL;

	/* set chaining flag in first SBALE of current SBAL */
	sbale = zfcp_qdio_sbale_req(fsf_req);
	sbale->flags |= SBAL_FLAGS0_MORE_SBALS;

	/* calculate index of next SBAL */
	fsf_req->sbal_last++;
	fsf_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;

	/* keep this requests number of SBALs up-to-date */
	fsf_req->sbal_number++;

	/* start at first SBALE of new SBAL */
	fsf_req->sbale_curr = 0;

	/* set storage-block type for new SBAL */
	sbale = zfcp_qdio_sbale_curr(fsf_req);
	sbale->flags |= sbtype;

	return sbale;
}

static struct qdio_buffer_element *
zfcp_qdio_sbale_next(struct zfcp_fsf_req *fsf_req, unsigned long sbtype)
{
	if (fsf_req->sbale_curr == ZFCP_LAST_SBALE_PER_SBAL)
		return zfcp_qdio_sbal_chain(fsf_req, sbtype);
	fsf_req->sbale_curr++;
	return zfcp_qdio_sbale_curr(fsf_req);
}

static void zfcp_qdio_undo_sbals(struct zfcp_fsf_req *fsf_req)
{
	struct qdio_buffer **sbal = fsf_req->adapter->req_q.sbal;
	int first = fsf_req->sbal_first;
	int last = fsf_req->sbal_last;
	int count = (last - first + QDIO_MAX_BUFFERS_PER_Q) %
		QDIO_MAX_BUFFERS_PER_Q + 1;
	zfcp_qdio_zero_sbals(sbal, first, count);
}

static int zfcp_qdio_fill_sbals(struct zfcp_fsf_req *fsf_req,
				unsigned int sbtype, void *start_addr,
				unsigned int total_length)
{
	struct qdio_buffer_element *sbale;
	unsigned long remaining, length;
	void *addr;

	/* split segment up */
	for (addr = start_addr, remaining = total_length; remaining > 0;
	     addr += length, remaining -= length) {
		sbale = zfcp_qdio_sbale_next(fsf_req, sbtype);
		if (!sbale) {
			atomic_inc(&fsf_req->adapter->qdio_outb_full);
			zfcp_qdio_undo_sbals(fsf_req);
			return -EINVAL;
		}

		/* new piece must not exceed next page boundary */
		length = min(remaining,
			     (PAGE_SIZE - ((unsigned long)addr &
					   (PAGE_SIZE - 1))));
		sbale->addr = addr;
		sbale->length = length;
	}
	return 0;
}

/**
 * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
 * @fsf_req: request to be processed
 * @sbtype: SBALE flags
 * @sg: scatter-gather list
 * @max_sbals: upper bound for number of SBALs to be used
 * Returns: number of bytes, or error (negativ)
 */
int zfcp_qdio_sbals_from_sg(struct zfcp_fsf_req *fsf_req, unsigned long sbtype,
			    struct scatterlist *sg, int max_sbals)
{
	struct qdio_buffer_element *sbale;
	int retval, bytes = 0;

	/* figure out last allowed SBAL */
	zfcp_qdio_sbal_limit(fsf_req, max_sbals);

	/* set storage-block type for this request */
	sbale = zfcp_qdio_sbale_req(fsf_req);
	sbale->flags |= sbtype;

	for (; sg; sg = sg_next(sg)) {
		retval = zfcp_qdio_fill_sbals(fsf_req, sbtype, sg_virt(sg),
					      sg->length);
		if (retval < 0)
			return retval;
		bytes += sg->length;
	}

	/* assume that no other SBALEs are to follow in the same SBAL */
	sbale = zfcp_qdio_sbale_curr(fsf_req);
	sbale->flags |= SBAL_FLAGS_LAST_ENTRY;

	return bytes;
}

/**
 * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
 * @fsf_req: pointer to struct zfcp_fsf_req
 * Returns: 0 on success, error otherwise
 */
int zfcp_qdio_send(struct zfcp_fsf_req *fsf_req)
{
	struct zfcp_adapter *adapter = fsf_req->adapter;
	struct zfcp_qdio_queue *req_q = &adapter->req_q;
	int first = fsf_req->sbal_first;
	int count = fsf_req->sbal_number;
	int retval, pci, pci_batch;
	struct qdio_buffer_element *sbale;

	/* acknowledgements for transferred buffers */
	pci_batch = adapter->req_q_pci_batch + count;
	if (unlikely(pci_batch >= ZFCP_QDIO_PCI_INTERVAL)) {
		pci_batch %= ZFCP_QDIO_PCI_INTERVAL;
		pci = first + count - (pci_batch + 1);
		pci %= QDIO_MAX_BUFFERS_PER_Q;
		sbale = zfcp_qdio_sbale(req_q, pci, 0);
		sbale->flags |= SBAL_FLAGS0_PCI;
	}

	zfcp_qdio_account(adapter);

	retval = do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0, first,
			 count);
	if (unlikely(retval)) {
		zfcp_qdio_zero_sbals(req_q->sbal, first, count);
		return retval;
	}

	/* account for transferred buffers */
	atomic_sub(count, &req_q->count);
	req_q->first += count;
	req_q->first %= QDIO_MAX_BUFFERS_PER_Q;
	adapter->req_q_pci_batch = pci_batch;
	return 0;
}

/**
 * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
 * @adapter: pointer to struct zfcp_adapter
 * Returns: -ENOMEM on memory allocation error or return value from
 *          qdio_allocate
 */
int zfcp_qdio_allocate(struct zfcp_adapter *adapter)
{
	struct qdio_initialize *init_data;

	if (zfcp_qdio_buffers_enqueue(adapter->req_q.sbal) ||
		   zfcp_qdio_buffers_enqueue(adapter->resp_q.sbal))
		return -ENOMEM;

	init_data = &adapter->qdio_init_data;

	init_data->cdev = adapter->ccw_device;
	init_data->q_format = QDIO_ZFCP_QFMT;
	memcpy(init_data->adapter_name, dev_name(&adapter->ccw_device->dev), 8);
	ASCEBC(init_data->adapter_name, 8);
	init_data->qib_param_field_format = 0;
	init_data->qib_param_field = NULL;
	init_data->input_slib_elements = NULL;
	init_data->output_slib_elements = NULL;
	init_data->no_input_qs = 1;
	init_data->no_output_qs = 1;
	init_data->input_handler = zfcp_qdio_int_resp;
	init_data->output_handler = zfcp_qdio_int_req;
	init_data->int_parm = (unsigned long) adapter;
	init_data->flags = QDIO_INBOUND_0COPY_SBALS |
			QDIO_OUTBOUND_0COPY_SBALS | QDIO_USE_OUTBOUND_PCIS;
	init_data->input_sbal_addr_array =
			(void **) (adapter->resp_q.sbal);
	init_data->output_sbal_addr_array =
			(void **) (adapter->req_q.sbal);

	return qdio_allocate(init_data);
}

/**
 * zfcp_close_qdio - close qdio queues for an adapter
 */
void zfcp_qdio_close(struct zfcp_adapter *adapter)
{
	struct zfcp_qdio_queue *req_q;
	int first, count;

	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
		return;

	/* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
	req_q = &adapter->req_q;
	spin_lock_bh(&adapter->req_q_lock);
	atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
	spin_unlock_bh(&adapter->req_q_lock);

	qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);

	/* cleanup used outbound sbals */
	count = atomic_read(&req_q->count);
	if (count < QDIO_MAX_BUFFERS_PER_Q) {
		first = (req_q->first + count) % QDIO_MAX_BUFFERS_PER_Q;
		count = QDIO_MAX_BUFFERS_PER_Q - count;
		zfcp_qdio_zero_sbals(req_q->sbal, first, count);
	}
	req_q->first = 0;
	atomic_set(&req_q->count, 0);
	adapter->req_q_pci_batch = 0;
	adapter->resp_q.first = 0;
	atomic_set(&adapter->resp_q.count, 0);
}

/**
 * zfcp_qdio_open - prepare and initialize response queue
 * @adapter: pointer to struct zfcp_adapter
 * Returns: 0 on success, otherwise -EIO
 */
int zfcp_qdio_open(struct zfcp_adapter *adapter)
{
	struct qdio_buffer_element *sbale;
	int cc;

	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
		return -EIO;

	if (qdio_establish(&adapter->qdio_init_data))
		goto failed_establish;

	if (qdio_activate(adapter->ccw_device))
		goto failed_qdio;

	for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
		sbale = &(adapter->resp_q.sbal[cc]->element[0]);
		sbale->length = 0;
		sbale->flags = SBAL_FLAGS_LAST_ENTRY;
		sbale->addr = NULL;
	}

	if (do_QDIO(adapter->ccw_device, QDIO_FLAG_SYNC_INPUT, 0, 0,
		     QDIO_MAX_BUFFERS_PER_Q))
		goto failed_qdio;

	/* set index of first avalable SBALS / number of available SBALS */
	adapter->req_q.first = 0;
	atomic_set(&adapter->req_q.count, QDIO_MAX_BUFFERS_PER_Q);
	adapter->req_q_pci_batch = 0;

	return 0;

failed_qdio:
	qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
failed_establish:
	dev_err(&adapter->ccw_device->dev,
		"Setting up the QDIO connection to the FCP adapter failed\n");
	return -EIO;
}