xref: /openbmc/linux/drivers/s390/scsi/zfcp_qdio.c (revision 6d99a79c)
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, 2010
8  */
9 
10 #define KMSG_COMPONENT "zfcp"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/slab.h>
14 #include <linux/module.h>
15 #include "zfcp_ext.h"
16 #include "zfcp_qdio.h"
17 
18 static bool enable_multibuffer = true;
19 module_param_named(datarouter, enable_multibuffer, bool, 0400);
20 MODULE_PARM_DESC(datarouter, "Enable hardware data router support (default on)");
21 
22 static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *id,
23 				    unsigned int qdio_err)
24 {
25 	struct zfcp_adapter *adapter = qdio->adapter;
26 
27 	dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n");
28 
29 	if (qdio_err & QDIO_ERROR_SLSB_STATE) {
30 		zfcp_qdio_siosl(adapter);
31 		zfcp_erp_adapter_shutdown(adapter, 0, id);
32 		return;
33 	}
34 	zfcp_erp_adapter_reopen(adapter,
35 				ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
36 				ZFCP_STATUS_COMMON_ERP_FAILED, id);
37 }
38 
39 static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt)
40 {
41 	int i, sbal_idx;
42 
43 	for (i = first; i < first + cnt; i++) {
44 		sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q;
45 		memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer));
46 	}
47 }
48 
49 /* this needs to be called prior to updating the queue fill level */
50 static inline void zfcp_qdio_account(struct zfcp_qdio *qdio)
51 {
52 	unsigned long long now, span;
53 	int used;
54 
55 	now = get_tod_clock_monotonic();
56 	span = (now - qdio->req_q_time) >> 12;
57 	used = QDIO_MAX_BUFFERS_PER_Q - atomic_read(&qdio->req_q_free);
58 	qdio->req_q_util += used * span;
59 	qdio->req_q_time = now;
60 }
61 
62 static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err,
63 			      int queue_no, int idx, int count,
64 			      unsigned long parm)
65 {
66 	struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
67 
68 	if (unlikely(qdio_err)) {
69 		zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err);
70 		return;
71 	}
72 
73 	/* cleanup all SBALs being program-owned now */
74 	zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
75 
76 	spin_lock_irq(&qdio->stat_lock);
77 	zfcp_qdio_account(qdio);
78 	spin_unlock_irq(&qdio->stat_lock);
79 	atomic_add(count, &qdio->req_q_free);
80 	wake_up(&qdio->req_q_wq);
81 }
82 
83 static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err,
84 			       int queue_no, int idx, int count,
85 			       unsigned long parm)
86 {
87 	struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm;
88 	struct zfcp_adapter *adapter = qdio->adapter;
89 	int sbal_no, sbal_idx;
90 
91 	if (unlikely(qdio_err)) {
92 		if (zfcp_adapter_multi_buffer_active(adapter)) {
93 			void *pl[ZFCP_QDIO_MAX_SBALS_PER_REQ + 1];
94 			struct qdio_buffer_element *sbale;
95 			u64 req_id;
96 			u8 scount;
97 
98 			memset(pl, 0,
99 			       ZFCP_QDIO_MAX_SBALS_PER_REQ * sizeof(void *));
100 			sbale = qdio->res_q[idx]->element;
101 			req_id = (u64) sbale->addr;
102 			scount = min(sbale->scount + 1,
103 				     ZFCP_QDIO_MAX_SBALS_PER_REQ + 1);
104 				     /* incl. signaling SBAL */
105 
106 			for (sbal_no = 0; sbal_no < scount; sbal_no++) {
107 				sbal_idx = (idx + sbal_no) %
108 					QDIO_MAX_BUFFERS_PER_Q;
109 				pl[sbal_no] = qdio->res_q[sbal_idx];
110 			}
111 			zfcp_dbf_hba_def_err(adapter, req_id, scount, pl);
112 		}
113 		zfcp_qdio_handler_error(qdio, "qdires1", qdio_err);
114 		return;
115 	}
116 
117 	/*
118 	 * go through all SBALs from input queue currently
119 	 * returned by QDIO layer
120 	 */
121 	for (sbal_no = 0; sbal_no < count; sbal_no++) {
122 		sbal_idx = (idx + sbal_no) % QDIO_MAX_BUFFERS_PER_Q;
123 		/* go through all SBALEs of SBAL */
124 		zfcp_fsf_reqid_check(qdio, sbal_idx);
125 	}
126 
127 	/*
128 	 * put SBALs back to response queue
129 	 */
130 	if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, idx, count))
131 		zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdires2");
132 }
133 
134 static struct qdio_buffer_element *
135 zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
136 {
137 	struct qdio_buffer_element *sbale;
138 
139 	/* set last entry flag in current SBALE of current SBAL */
140 	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
141 	sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
142 
143 	/* don't exceed last allowed SBAL */
144 	if (q_req->sbal_last == q_req->sbal_limit)
145 		return NULL;
146 
147 	/* set chaining flag in first SBALE of current SBAL */
148 	sbale = zfcp_qdio_sbale_req(qdio, q_req);
149 	sbale->sflags |= SBAL_SFLAGS0_MORE_SBALS;
150 
151 	/* calculate index of next SBAL */
152 	q_req->sbal_last++;
153 	q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q;
154 
155 	/* keep this requests number of SBALs up-to-date */
156 	q_req->sbal_number++;
157 	BUG_ON(q_req->sbal_number > ZFCP_QDIO_MAX_SBALS_PER_REQ);
158 
159 	/* start at first SBALE of new SBAL */
160 	q_req->sbale_curr = 0;
161 
162 	/* set storage-block type for new SBAL */
163 	sbale = zfcp_qdio_sbale_curr(qdio, q_req);
164 	sbale->sflags |= q_req->sbtype;
165 
166 	return sbale;
167 }
168 
169 static struct qdio_buffer_element *
170 zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
171 {
172 	if (q_req->sbale_curr == qdio->max_sbale_per_sbal - 1)
173 		return zfcp_qdio_sbal_chain(qdio, q_req);
174 	q_req->sbale_curr++;
175 	return zfcp_qdio_sbale_curr(qdio, q_req);
176 }
177 
178 /**
179  * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list
180  * @qdio: pointer to struct zfcp_qdio
181  * @q_req: pointer to struct zfcp_qdio_req
182  * @sg: scatter-gather list
183  * @max_sbals: upper bound for number of SBALs to be used
184  * Returns: zero or -EINVAL on error
185  */
186 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
187 			    struct scatterlist *sg)
188 {
189 	struct qdio_buffer_element *sbale;
190 
191 	/* set storage-block type for this request */
192 	sbale = zfcp_qdio_sbale_req(qdio, q_req);
193 	sbale->sflags |= q_req->sbtype;
194 
195 	for (; sg; sg = sg_next(sg)) {
196 		sbale = zfcp_qdio_sbale_next(qdio, q_req);
197 		if (!sbale) {
198 			atomic_inc(&qdio->req_q_full);
199 			zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
200 					     q_req->sbal_number);
201 			return -EINVAL;
202 		}
203 		sbale->addr = sg_virt(sg);
204 		sbale->length = sg->length;
205 	}
206 	return 0;
207 }
208 
209 static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
210 {
211 	if (atomic_read(&qdio->req_q_free) ||
212 	    !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
213 		return 1;
214 	return 0;
215 }
216 
217 /**
218  * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
219  * @qdio: pointer to struct zfcp_qdio
220  *
221  * The req_q_lock must be held by the caller of this function, and
222  * this function may only be called from process context; it will
223  * sleep when waiting for a free sbal.
224  *
225  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
226  */
227 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
228 {
229 	long ret;
230 
231 	ret = wait_event_interruptible_lock_irq_timeout(qdio->req_q_wq,
232 		       zfcp_qdio_sbal_check(qdio), qdio->req_q_lock, 5 * HZ);
233 
234 	if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
235 		return -EIO;
236 
237 	if (ret > 0)
238 		return 0;
239 
240 	if (!ret) {
241 		atomic_inc(&qdio->req_q_full);
242 		/* assume hanging outbound queue, try queue recovery */
243 		zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1");
244 	}
245 
246 	return -EIO;
247 }
248 
249 /**
250  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
251  * @qdio: pointer to struct zfcp_qdio
252  * @q_req: pointer to struct zfcp_qdio_req
253  * Returns: 0 on success, error otherwise
254  */
255 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
256 {
257 	int retval;
258 	u8 sbal_number = q_req->sbal_number;
259 
260 	spin_lock(&qdio->stat_lock);
261 	zfcp_qdio_account(qdio);
262 	spin_unlock(&qdio->stat_lock);
263 
264 	retval = do_QDIO(qdio->adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0,
265 			 q_req->sbal_first, sbal_number);
266 
267 	if (unlikely(retval)) {
268 		zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
269 				     sbal_number);
270 		return retval;
271 	}
272 
273 	/* account for transferred buffers */
274 	atomic_sub(sbal_number, &qdio->req_q_free);
275 	qdio->req_q_idx += sbal_number;
276 	qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
277 
278 	return 0;
279 }
280 
281 
282 static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
283 				      struct zfcp_qdio *qdio)
284 {
285 	memset(id, 0, sizeof(*id));
286 	id->cdev = qdio->adapter->ccw_device;
287 	id->q_format = QDIO_ZFCP_QFMT;
288 	memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
289 	ASCEBC(id->adapter_name, 8);
290 	id->qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
291 	if (enable_multibuffer)
292 		id->qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
293 	id->no_input_qs = 1;
294 	id->no_output_qs = 1;
295 	id->input_handler = zfcp_qdio_int_resp;
296 	id->output_handler = zfcp_qdio_int_req;
297 	id->int_parm = (unsigned long) qdio;
298 	id->input_sbal_addr_array = (void **) (qdio->res_q);
299 	id->output_sbal_addr_array = (void **) (qdio->req_q);
300 	id->scan_threshold =
301 		QDIO_MAX_BUFFERS_PER_Q - ZFCP_QDIO_MAX_SBALS_PER_REQ * 2;
302 }
303 
304 /**
305  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
306  * @adapter: pointer to struct zfcp_adapter
307  * Returns: -ENOMEM on memory allocation error or return value from
308  *          qdio_allocate
309  */
310 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
311 {
312 	struct qdio_initialize init_data;
313 	int ret;
314 
315 	ret = qdio_alloc_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
316 	if (ret)
317 		return -ENOMEM;
318 
319 	ret = qdio_alloc_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
320 	if (ret)
321 		goto free_req_q;
322 
323 	zfcp_qdio_setup_init_data(&init_data, qdio);
324 	init_waitqueue_head(&qdio->req_q_wq);
325 
326 	ret = qdio_allocate(&init_data);
327 	if (ret)
328 		goto free_res_q;
329 
330 	return 0;
331 
332 free_res_q:
333 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
334 free_req_q:
335 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
336 	return ret;
337 }
338 
339 /**
340  * zfcp_close_qdio - close qdio queues for an adapter
341  * @qdio: pointer to structure zfcp_qdio
342  */
343 void zfcp_qdio_close(struct zfcp_qdio *qdio)
344 {
345 	struct zfcp_adapter *adapter = qdio->adapter;
346 	int idx, count;
347 
348 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
349 		return;
350 
351 	/* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
352 	spin_lock_irq(&qdio->req_q_lock);
353 	atomic_andnot(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
354 	spin_unlock_irq(&qdio->req_q_lock);
355 
356 	wake_up(&qdio->req_q_wq);
357 
358 	qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
359 
360 	/* cleanup used outbound sbals */
361 	count = atomic_read(&qdio->req_q_free);
362 	if (count < QDIO_MAX_BUFFERS_PER_Q) {
363 		idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
364 		count = QDIO_MAX_BUFFERS_PER_Q - count;
365 		zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
366 	}
367 	qdio->req_q_idx = 0;
368 	atomic_set(&qdio->req_q_free, 0);
369 }
370 
371 /**
372  * zfcp_qdio_open - prepare and initialize response queue
373  * @qdio: pointer to struct zfcp_qdio
374  * Returns: 0 on success, otherwise -EIO
375  */
376 int zfcp_qdio_open(struct zfcp_qdio *qdio)
377 {
378 	struct qdio_buffer_element *sbale;
379 	struct qdio_initialize init_data;
380 	struct zfcp_adapter *adapter = qdio->adapter;
381 	struct ccw_device *cdev = adapter->ccw_device;
382 	struct qdio_ssqd_desc ssqd;
383 	int cc;
384 
385 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
386 		return -EIO;
387 
388 	atomic_andnot(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
389 			  &qdio->adapter->status);
390 
391 	zfcp_qdio_setup_init_data(&init_data, qdio);
392 
393 	if (qdio_establish(&init_data))
394 		goto failed_establish;
395 
396 	if (qdio_get_ssqd_desc(init_data.cdev, &ssqd))
397 		goto failed_qdio;
398 
399 	if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
400 		atomic_or(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
401 				&qdio->adapter->status);
402 
403 	if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
404 		atomic_or(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
405 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
406 	} else {
407 		atomic_andnot(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
408 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1;
409 	}
410 
411 	qdio->max_sbale_per_req =
412 		ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal
413 		- 2;
414 	if (qdio_activate(cdev))
415 		goto failed_qdio;
416 
417 	for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
418 		sbale = &(qdio->res_q[cc]->element[0]);
419 		sbale->length = 0;
420 		sbale->eflags = SBAL_EFLAGS_LAST_ENTRY;
421 		sbale->sflags = 0;
422 		sbale->addr = NULL;
423 	}
424 
425 	if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
426 		goto failed_qdio;
427 
428 	/* set index of first available SBALS / number of available SBALS */
429 	qdio->req_q_idx = 0;
430 	atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
431 	atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
432 
433 	if (adapter->scsi_host) {
434 		adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
435 		adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
436 	}
437 
438 	return 0;
439 
440 failed_qdio:
441 	qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
442 failed_establish:
443 	dev_err(&cdev->dev,
444 		"Setting up the QDIO connection to the FCP adapter failed\n");
445 	return -EIO;
446 }
447 
448 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
449 {
450 	if (!qdio)
451 		return;
452 
453 	if (qdio->adapter->ccw_device)
454 		qdio_free(qdio->adapter->ccw_device);
455 
456 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
457 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
458 	kfree(qdio);
459 }
460 
461 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
462 {
463 	struct zfcp_qdio *qdio;
464 
465 	qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
466 	if (!qdio)
467 		return -ENOMEM;
468 
469 	qdio->adapter = adapter;
470 
471 	if (zfcp_qdio_allocate(qdio)) {
472 		kfree(qdio);
473 		return -ENOMEM;
474 	}
475 
476 	spin_lock_init(&qdio->req_q_lock);
477 	spin_lock_init(&qdio->stat_lock);
478 
479 	adapter->qdio = qdio;
480 	return 0;
481 }
482 
483 /**
484  * zfcp_qdio_siosl - Trigger logging in FCP channel
485  * @adapter: The zfcp_adapter where to trigger logging
486  *
487  * Call the cio siosl function to trigger hardware logging.  This
488  * wrapper function sets a flag to ensure hardware logging is only
489  * triggered once before going through qdio shutdown.
490  *
491  * The triggers are always run from qdio tasklet context, so no
492  * additional synchronization is necessary.
493  */
494 void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
495 {
496 	int rc;
497 
498 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
499 		return;
500 
501 	rc = ccw_device_siosl(adapter->ccw_device);
502 	if (!rc)
503 		atomic_or(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
504 				&adapter->status);
505 }
506