xref: /openbmc/linux/drivers/s390/scsi/zfcp_qdio.c (revision 2326f3cd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * zfcp device driver
4  *
5  * Setup and helper functions to access QDIO.
6  *
7  * Copyright IBM Corp. 2002, 2020
8  */
9 
10 #define KMSG_COMPONENT "zfcp"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/lockdep.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include "zfcp_ext.h"
17 #include "zfcp_qdio.h"
18 
19 static bool enable_multibuffer = true;
20 module_param_named(datarouter, enable_multibuffer, bool, 0400);
21 MODULE_PARM_DESC(datarouter, "Enable hardware data router support (default on)");
22 
23 #define ZFCP_QDIO_REQUEST_RESCAN_MSECS	(MSEC_PER_SEC * 10)
24 #define ZFCP_QDIO_REQUEST_SCAN_MSECS	MSEC_PER_SEC
25 
26 static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *dbftag,
27 				    unsigned int qdio_err)
28 {
29 	struct zfcp_adapter *adapter = qdio->adapter;
30 
31 	dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
32 
33 	if (qdio_err & QDIO_ERROR_SLSB_STATE) {
34 		zfcp_qdio_siosl(adapter);
35 		zfcp_erp_adapter_shutdown(adapter, 0, dbftag);
36 		return;
37 	}
38 	zfcp_erp_adapter_reopen(adapter,
39 				ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
40 				ZFCP_STATUS_COMMON_ERP_FAILED, dbftag);
41 }
42 
43 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
44 {
45 	int i, sbal_idx;
46 
47 	for (i = first; i < first + cnt; i++) {
48 		sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
49 		memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
50 	}
51 }
52 
53 /* this needs to be called prior to updating the queue fill level */
54 static inline void zfcp_qdio_account(struct zfcp_qdio *qdio)
55 {
56 	unsigned long long now, span;
57 	int used;
58 
59 	now = get_tod_clock_monotonic();
60 	span = (now - qdio->req_q_time) >> 12;
61 	used = QDIO_MAX_BUFFERS_PER_Q - atomic_read(&qdio->req_q_free);
62 	qdio->req_q_util += used * span;
63 	qdio->req_q_time = now;
64 }
65 
66 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
67 			      int queue_no, int idx, int count,
68 			      unsigned long parm)
69 {
70 	struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
71 
72 	zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err);
73 }
74 
75 static void zfcp_qdio_request_tasklet(struct tasklet_struct *tasklet)
76 {
77 	struct zfcp_qdio *qdio = from_tasklet(qdio, tasklet, request_tasklet);
78 	struct ccw_device *cdev = qdio->adapter->ccw_device;
79 	unsigned int start, error;
80 	int completed;
81 
82 	completed = qdio_inspect_queue(cdev, 0, false, &start, &error);
83 	if (completed > 0) {
84 		if (error) {
85 			zfcp_qdio_handler_error(qdio, "qdreqt1", error);
86 		} else {
87 			/* cleanup all SBALs being program-owned now */
88 			zfcp_qdio_zero_sbals(qdio->req_q, start, completed);
89 
90 			spin_lock_irq(&qdio->stat_lock);
91 			zfcp_qdio_account(qdio);
92 			spin_unlock_irq(&qdio->stat_lock);
93 			atomic_add(completed, &qdio->req_q_free);
94 			wake_up(&qdio->req_q_wq);
95 		}
96 	}
97 
98 	if (atomic_read(&qdio->req_q_free) < QDIO_MAX_BUFFERS_PER_Q)
99 		timer_reduce(&qdio->request_timer,
100 			     jiffies + msecs_to_jiffies(ZFCP_QDIO_REQUEST_RESCAN_MSECS));
101 }
102 
103 static void zfcp_qdio_request_timer(struct timer_list *timer)
104 {
105 	struct zfcp_qdio *qdio = from_timer(qdio, timer, request_timer);
106 
107 	tasklet_schedule(&qdio->request_tasklet);
108 }
109 
110 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
111 			       int queue_no, int idx, int count,
112 			       unsigned long parm)
113 {
114 	struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
115 	struct zfcp_adapter *adapter = qdio->adapter;
116 	int sbal_no, sbal_idx;
117 
118 	if (unlikely(qdio_err)) {
119 		if (zfcp_adapter_multi_buffer_active(adapter)) {
120 			void *pl[ZFCP_QDIO_MAX_SBALS_PER_REQ + 1];
121 			struct qdio_buffer_element *sbale;
122 			u64 req_id;
123 			u8 scount;
124 
125 			memset(pl, 0,
126 			       ZFCP_QDIO_MAX_SBALS_PER_REQ * sizeof(void *));
127 			sbale = qdio->res_q[idx]->element;
128 			req_id = sbale->addr;
129 			scount = min(sbale->scount + 1,
130 				     ZFCP_QDIO_MAX_SBALS_PER_REQ + 1);
131 				     /* incl. signaling SBAL */
132 
133 			for (sbal_no = 0; sbal_no < scount; sbal_no++) {
134 				sbal_idx = (idx + sbal_no) %
135 					QDIO_MAX_BUFFERS_PER_Q;
136 				pl[sbal_no] = qdio->res_q[sbal_idx];
137 			}
138 			zfcp_dbf_hba_def_err(adapter, req_id, scount, pl);
139 		}
140 		zfcp_qdio_handler_error(qdio, "qdires1", qdio_err);
141 		return;
142 	}
143 
144 	/*
145 	 * go through all SBALs from input queue currently
146 	 * returned by QDIO layer
147 	 */
148 	for (sbal_no = 0; sbal_no < count; sbal_no++) {
149 		sbal_idx = (idx + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
150 		/* go through all SBALEs of SBAL */
151 		zfcp_fsf_reqid_check(qdio, sbal_idx);
152 	}
153 
154 	/*
155 	 * put SBALs back to response queue
156 	 */
157 	if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, idx, count, NULL))
158 		zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdires2");
159 }
160 
161 static void zfcp_qdio_irq_tasklet(struct tasklet_struct *tasklet)
162 {
163 	struct zfcp_qdio *qdio = from_tasklet(qdio, tasklet, irq_tasklet);
164 	struct ccw_device *cdev = qdio->adapter->ccw_device;
165 	unsigned int start, error;
166 	int completed;
167 
168 	if (atomic_read(&qdio->req_q_free) < QDIO_MAX_BUFFERS_PER_Q)
169 		tasklet_schedule(&qdio->request_tasklet);
170 
171 	/* Check the Response Queue: */
172 	completed = qdio_inspect_queue(cdev, 0, true, &start, &error);
173 	if (completed < 0)
174 		return;
175 	if (completed > 0)
176 		zfcp_qdio_int_resp(cdev, error, 0, start, completed,
177 				   (unsigned long) qdio);
178 
179 	if (qdio_start_irq(cdev))
180 		/* More work pending: */
181 		tasklet_schedule(&qdio->irq_tasklet);
182 }
183 
184 static void zfcp_qdio_poll(struct ccw_device *cdev, unsigned long data)
185 {
186 	struct zfcp_qdio *qdio = (struct zfcp_qdio *) data;
187 
188 	tasklet_schedule(&qdio->irq_tasklet);
189 }
190 
191 static struct qdio_buffer_element *
192 zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
193 {
194 	struct qdio_buffer_element *sbale;
195 
196 	/* set last entry flag in current SBALE of current SBAL */
197 	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
198 	sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
199 
200 	/* don't exceed last allowed SBAL */
201 	if (q_req->sbal_last == q_req->sbal_limit)
202 		return NULL;
203 
204 	/* set chaining flag in first SBALE of current SBAL */
205 	sbale = zfcp_qdio_sbale_req(qdio, q_req);
206 	sbale->sflags |= SBAL_SFLAGS0_MORE_SBALS;
207 
208 	/* calculate index of next SBAL */
209 	q_req->sbal_last++;
210 	q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
211 
212 	/* keep this requests number of SBALs up-to-date */
213 	q_req->sbal_number++;
214 	BUG_ON(q_req->sbal_number > ZFCP_QDIO_MAX_SBALS_PER_REQ);
215 
216 	/* start at first SBALE of new SBAL */
217 	q_req->sbale_curr = 0;
218 
219 	/* set storage-block type for new SBAL */
220 	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
221 	sbale->sflags |= q_req->sbtype;
222 
223 	return sbale;
224 }
225 
226 static struct qdio_buffer_element *
227 zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
228 {
229 	if (q_req->sbale_curr == qdio->max_sbale_per_sbal - 1)
230 		return zfcp_qdio_sbal_chain(qdio, q_req);
231 	q_req->sbale_curr++;
232 	return zfcp_qdio_sbale_curr(qdio, q_req);
233 }
234 
235 /**
236  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
237  * @qdio: pointer to struct zfcp_qdio
238  * @q_req: pointer to struct zfcp_qdio_req
239  * @sg: scatter-gather list
240  * Returns: zero or -EINVAL on error
241  */
242 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
243 			    struct scatterlist *sg)
244 {
245 	struct qdio_buffer_element *sbale;
246 
247 	/* set storage-block type for this request */
248 	sbale = zfcp_qdio_sbale_req(qdio, q_req);
249 	sbale->sflags |= q_req->sbtype;
250 
251 	for (; sg; sg = sg_next(sg)) {
252 		sbale = zfcp_qdio_sbale_next(qdio, q_req);
253 		if (!sbale) {
254 			atomic_inc(&qdio->req_q_full);
255 			zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
256 					     q_req->sbal_number);
257 			return -EINVAL;
258 		}
259 		sbale->addr = sg_phys(sg);
260 		sbale->length = sg->length;
261 	}
262 	return 0;
263 }
264 
265 static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
266 {
267 	if (atomic_read(&qdio->req_q_free) ||
268 	    !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
269 		return 1;
270 	return 0;
271 }
272 
273 /**
274  * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
275  * @qdio: pointer to struct zfcp_qdio
276  *
277  * The req_q_lock must be held by the caller of this function, and
278  * this function may only be called from process context; it will
279  * sleep when waiting for a free sbal.
280  *
281  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
282  */
283 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
284 {
285 	long ret;
286 
287 	ret = wait_event_interruptible_lock_irq_timeout(qdio->req_q_wq,
288 		       zfcp_qdio_sbal_check(qdio), qdio->req_q_lock, 5 * HZ);
289 
290 	if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
291 		return -EIO;
292 
293 	if (ret > 0)
294 		return 0;
295 
296 	if (!ret) {
297 		atomic_inc(&qdio->req_q_full);
298 		/* assume hanging outbound queue, try queue recovery */
299 		zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1");
300 	}
301 
302 	return -EIO;
303 }
304 
305 /**
306  * zfcp_qdio_send - send req to QDIO
307  * @qdio: pointer to struct zfcp_qdio
308  * @q_req: pointer to struct zfcp_qdio_req
309  * Returns: 0 on success, error otherwise
310  */
311 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
312 {
313 	int retval;
314 	u8 sbal_number = q_req->sbal_number;
315 
316 	/*
317 	 * This should actually be a spin_lock_bh(stat_lock), to protect against
318 	 * Request Queue completion processing in tasklet context.
319 	 * But we can't do so (and are safe), as we always get called with IRQs
320 	 * disabled by spin_lock_irq[save](req_q_lock).
321 	 */
322 	lockdep_assert_irqs_disabled();
323 	spin_lock(&qdio->stat_lock);
324 	zfcp_qdio_account(qdio);
325 	spin_unlock(&qdio->stat_lock);
326 
327 	atomic_sub(sbal_number, &qdio->req_q_free);
328 
329 	retval = do_QDIO(qdio->adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0,
330 			 q_req->sbal_first, sbal_number, NULL);
331 
332 	if (unlikely(retval)) {
333 		/* Failed to submit the IO, roll back our modifications. */
334 		atomic_add(sbal_number, &qdio->req_q_free);
335 		zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
336 				     sbal_number);
337 		return retval;
338 	}
339 
340 	if (atomic_read(&qdio->req_q_free) <= 2 * ZFCP_QDIO_MAX_SBALS_PER_REQ)
341 		tasklet_schedule(&qdio->request_tasklet);
342 	else
343 		timer_reduce(&qdio->request_timer,
344 			     jiffies + msecs_to_jiffies(ZFCP_QDIO_REQUEST_SCAN_MSECS));
345 
346 	/* account for transferred buffers */
347 	qdio->req_q_idx += sbal_number;
348 	qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
349 
350 	return 0;
351 }
352 
353 /**
354  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
355  * @qdio: pointer to struct zfcp_qdio
356  * Returns: -ENOMEM on memory allocation error or return value from
357  *          qdio_allocate
358  */
359 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
360 {
361 	int ret;
362 
363 	ret = qdio_alloc_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
364 	if (ret)
365 		return -ENOMEM;
366 
367 	ret = qdio_alloc_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
368 	if (ret)
369 		goto free_req_q;
370 
371 	init_waitqueue_head(&qdio->req_q_wq);
372 
373 	ret = qdio_allocate(qdio->adapter->ccw_device, 1, 1);
374 	if (ret)
375 		goto free_res_q;
376 
377 	return 0;
378 
379 free_res_q:
380 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
381 free_req_q:
382 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
383 	return ret;
384 }
385 
386 /**
387  * zfcp_qdio_close - close qdio queues for an adapter
388  * @qdio: pointer to structure zfcp_qdio
389  */
390 void zfcp_qdio_close(struct zfcp_qdio *qdio)
391 {
392 	struct zfcp_adapter *adapter = qdio->adapter;
393 	int idx, count;
394 
395 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
396 		return;
397 
398 	/* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
399 	spin_lock_irq(&qdio->req_q_lock);
400 	atomic_andnot(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
401 	spin_unlock_irq(&qdio->req_q_lock);
402 
403 	wake_up(&qdio->req_q_wq);
404 
405 	tasklet_disable(&qdio->irq_tasklet);
406 	tasklet_disable(&qdio->request_tasklet);
407 	del_timer_sync(&qdio->request_timer);
408 	qdio_stop_irq(adapter->ccw_device);
409 	qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
410 
411 	/* cleanup used outbound sbals */
412 	count = atomic_read(&qdio->req_q_free);
413 	if (count < QDIO_MAX_BUFFERS_PER_Q) {
414 		idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
415 		count = QDIO_MAX_BUFFERS_PER_Q - count;
416 		zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
417 	}
418 	qdio->req_q_idx = 0;
419 	atomic_set(&qdio->req_q_free, 0);
420 }
421 
422 void zfcp_qdio_shost_update(struct zfcp_adapter *const adapter,
423 			    const struct zfcp_qdio *const qdio)
424 {
425 	struct Scsi_Host *const shost = adapter->scsi_host;
426 
427 	if (shost == NULL)
428 		return;
429 
430 	shost->sg_tablesize = qdio->max_sbale_per_req;
431 	shost->max_sectors = qdio->max_sbale_per_req * 8;
432 }
433 
434 /**
435  * zfcp_qdio_open - prepare and initialize response queue
436  * @qdio: pointer to struct zfcp_qdio
437  * Returns: 0 on success, otherwise -EIO
438  */
439 int zfcp_qdio_open(struct zfcp_qdio *qdio)
440 {
441 	struct qdio_buffer **input_sbals[1] = {qdio->res_q};
442 	struct qdio_buffer **output_sbals[1] = {qdio->req_q};
443 	struct qdio_buffer_element *sbale;
444 	struct qdio_initialize init_data = {0};
445 	struct zfcp_adapter *adapter = qdio->adapter;
446 	struct ccw_device *cdev = adapter->ccw_device;
447 	struct qdio_ssqd_desc ssqd;
448 	int cc;
449 
450 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
451 		return -EIO;
452 
453 	atomic_andnot(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
454 			  &qdio->adapter->status);
455 
456 	init_data.q_format = QDIO_ZFCP_QFMT;
457 	init_data.qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
458 	if (enable_multibuffer)
459 		init_data.qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
460 	init_data.no_input_qs = 1;
461 	init_data.no_output_qs = 1;
462 	init_data.input_handler = zfcp_qdio_int_resp;
463 	init_data.output_handler = zfcp_qdio_int_req;
464 	init_data.irq_poll = zfcp_qdio_poll;
465 	init_data.int_parm = (unsigned long) qdio;
466 	init_data.input_sbal_addr_array = input_sbals;
467 	init_data.output_sbal_addr_array = output_sbals;
468 
469 	if (qdio_establish(cdev, &init_data))
470 		goto failed_establish;
471 
472 	if (qdio_get_ssqd_desc(cdev, &ssqd))
473 		goto failed_qdio;
474 
475 	if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
476 		atomic_or(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
477 				&qdio->adapter->status);
478 
479 	if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
480 		atomic_or(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
481 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
482 	} else {
483 		atomic_andnot(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
484 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1;
485 	}
486 
487 	qdio->max_sbale_per_req =
488 		ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal
489 		- 2;
490 	if (qdio_activate(cdev))
491 		goto failed_qdio;
492 
493 	for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
494 		sbale = &(qdio->res_q[cc]->element[0]);
495 		sbale->length = 0;
496 		sbale->eflags = SBAL_EFLAGS_LAST_ENTRY;
497 		sbale->sflags = 0;
498 		sbale->addr = 0;
499 	}
500 
501 	if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q,
502 		    NULL))
503 		goto failed_qdio;
504 
505 	/* set index of first available SBALS / number of available SBALS */
506 	qdio->req_q_idx = 0;
507 	atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
508 	atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
509 
510 	/* Enable processing for Request Queue completions: */
511 	tasklet_enable(&qdio->request_tasklet);
512 	/* Enable processing for QDIO interrupts: */
513 	tasklet_enable(&qdio->irq_tasklet);
514 	/* This results in a qdio_start_irq(): */
515 	tasklet_schedule(&qdio->irq_tasklet);
516 
517 	zfcp_qdio_shost_update(adapter, qdio);
518 
519 	return 0;
520 
521 failed_qdio:
522 	qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
523 failed_establish:
524 	dev_err(&cdev->dev,
525 		"Setting up the QDIO connection to the FCP adapter failed\n");
526 	return -EIO;
527 }
528 
529 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
530 {
531 	if (!qdio)
532 		return;
533 
534 	tasklet_kill(&qdio->irq_tasklet);
535 	tasklet_kill(&qdio->request_tasklet);
536 
537 	if (qdio->adapter->ccw_device)
538 		qdio_free(qdio->adapter->ccw_device);
539 
540 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
541 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
542 	kfree(qdio);
543 }
544 
545 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
546 {
547 	struct zfcp_qdio *qdio;
548 
549 	qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
550 	if (!qdio)
551 		return -ENOMEM;
552 
553 	qdio->adapter = adapter;
554 
555 	if (zfcp_qdio_allocate(qdio)) {
556 		kfree(qdio);
557 		return -ENOMEM;
558 	}
559 
560 	spin_lock_init(&qdio->req_q_lock);
561 	spin_lock_init(&qdio->stat_lock);
562 	timer_setup(&qdio->request_timer, zfcp_qdio_request_timer, 0);
563 	tasklet_setup(&qdio->irq_tasklet, zfcp_qdio_irq_tasklet);
564 	tasklet_setup(&qdio->request_tasklet, zfcp_qdio_request_tasklet);
565 	tasklet_disable(&qdio->irq_tasklet);
566 	tasklet_disable(&qdio->request_tasklet);
567 
568 	adapter->qdio = qdio;
569 	return 0;
570 }
571 
572 /**
573  * zfcp_qdio_siosl - Trigger logging in FCP channel
574  * @adapter: The zfcp_adapter where to trigger logging
575  *
576  * Call the cio siosl function to trigger hardware logging.  This
577  * wrapper function sets a flag to ensure hardware logging is only
578  * triggered once before going through qdio shutdown.
579  *
580  * The triggers are always run from qdio tasklet context, so no
581  * additional synchronization is necessary.
582  */
583 void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
584 {
585 	int rc;
586 
587 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
588 		return;
589 
590 	rc = ccw_device_siosl(adapter->ccw_device);
591 	if (!rc)
592 		atomic_or(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
593 				&adapter->status);
594 }
595