xref: /openbmc/linux/drivers/s390/scsi/zfcp_qdio.c (revision 8b030a57)
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, 2017
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 *dbftag,
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, dbftag);
32 		return;
33 	}
34 	zfcp_erp_adapter_reopen(adapter,
35 				ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
36 				ZFCP_STATUS_COMMON_ERP_FAILED, dbftag);
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  * Returns: zero or -EINVAL on error
184  */
185 int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
186 			    struct scatterlist *sg)
187 {
188 	struct qdio_buffer_element *sbale;
189 
190 	/* set storage-block type for this request */
191 	sbale = zfcp_qdio_sbale_req(qdio, q_req);
192 	sbale->sflags |= q_req->sbtype;
193 
194 	for (; sg; sg = sg_next(sg)) {
195 		sbale = zfcp_qdio_sbale_next(qdio, q_req);
196 		if (!sbale) {
197 			atomic_inc(&qdio->req_q_full);
198 			zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
199 					     q_req->sbal_number);
200 			return -EINVAL;
201 		}
202 		sbale->addr = sg_virt(sg);
203 		sbale->length = sg->length;
204 	}
205 	return 0;
206 }
207 
208 static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
209 {
210 	if (atomic_read(&qdio->req_q_free) ||
211 	    !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
212 		return 1;
213 	return 0;
214 }
215 
216 /**
217  * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary
218  * @qdio: pointer to struct zfcp_qdio
219  *
220  * The req_q_lock must be held by the caller of this function, and
221  * this function may only be called from process context; it will
222  * sleep when waiting for a free sbal.
223  *
224  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
225  */
226 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
227 {
228 	long ret;
229 
230 	ret = wait_event_interruptible_lock_irq_timeout(qdio->req_q_wq,
231 		       zfcp_qdio_sbal_check(qdio), qdio->req_q_lock, 5 * HZ);
232 
233 	if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
234 		return -EIO;
235 
236 	if (ret > 0)
237 		return 0;
238 
239 	if (!ret) {
240 		atomic_inc(&qdio->req_q_full);
241 		/* assume hanging outbound queue, try queue recovery */
242 		zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1");
243 	}
244 
245 	return -EIO;
246 }
247 
248 /**
249  * zfcp_qdio_send - set PCI flag in first SBALE and send req to QDIO
250  * @qdio: pointer to struct zfcp_qdio
251  * @q_req: pointer to struct zfcp_qdio_req
252  * Returns: 0 on success, error otherwise
253  */
254 int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
255 {
256 	int retval;
257 	u8 sbal_number = q_req->sbal_number;
258 
259 	spin_lock(&qdio->stat_lock);
260 	zfcp_qdio_account(qdio);
261 	spin_unlock(&qdio->stat_lock);
262 
263 	retval = do_QDIO(qdio->adapter->ccw_device, QDIO_FLAG_SYNC_OUTPUT, 0,
264 			 q_req->sbal_first, sbal_number);
265 
266 	if (unlikely(retval)) {
267 		zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first,
268 				     sbal_number);
269 		return retval;
270 	}
271 
272 	/* account for transferred buffers */
273 	atomic_sub(sbal_number, &qdio->req_q_free);
274 	qdio->req_q_idx += sbal_number;
275 	qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q;
276 
277 	return 0;
278 }
279 
280 
281 static void zfcp_qdio_setup_init_data(struct qdio_initialize *id,
282 				      struct zfcp_qdio *qdio)
283 {
284 	memset(id, 0, sizeof(*id));
285 	id->cdev = qdio->adapter->ccw_device;
286 	id->q_format = QDIO_ZFCP_QFMT;
287 	memcpy(id->adapter_name, dev_name(&id->cdev->dev), 8);
288 	ASCEBC(id->adapter_name, 8);
289 	id->qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
290 	if (enable_multibuffer)
291 		id->qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
292 	id->no_input_qs = 1;
293 	id->no_output_qs = 1;
294 	id->input_handler = zfcp_qdio_int_resp;
295 	id->output_handler = zfcp_qdio_int_req;
296 	id->int_parm = (unsigned long) qdio;
297 	id->input_sbal_addr_array = (void **) (qdio->res_q);
298 	id->output_sbal_addr_array = (void **) (qdio->req_q);
299 	id->scan_threshold =
300 		QDIO_MAX_BUFFERS_PER_Q - ZFCP_QDIO_MAX_SBALS_PER_REQ * 2;
301 }
302 
303 /**
304  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
305  * @qdio: pointer to struct zfcp_qdio
306  * Returns: -ENOMEM on memory allocation error or return value from
307  *          qdio_allocate
308  */
309 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
310 {
311 	struct qdio_initialize init_data;
312 	int ret;
313 
314 	ret = qdio_alloc_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
315 	if (ret)
316 		return -ENOMEM;
317 
318 	ret = qdio_alloc_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
319 	if (ret)
320 		goto free_req_q;
321 
322 	zfcp_qdio_setup_init_data(&init_data, qdio);
323 	init_waitqueue_head(&qdio->req_q_wq);
324 
325 	ret = qdio_allocate(&init_data);
326 	if (ret)
327 		goto free_res_q;
328 
329 	return 0;
330 
331 free_res_q:
332 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
333 free_req_q:
334 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
335 	return ret;
336 }
337 
338 /**
339  * zfcp_close_qdio - close qdio queues for an adapter
340  * @qdio: pointer to structure zfcp_qdio
341  */
342 void zfcp_qdio_close(struct zfcp_qdio *qdio)
343 {
344 	struct zfcp_adapter *adapter = qdio->adapter;
345 	int idx, count;
346 
347 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
348 		return;
349 
350 	/* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
351 	spin_lock_irq(&qdio->req_q_lock);
352 	atomic_andnot(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
353 	spin_unlock_irq(&qdio->req_q_lock);
354 
355 	wake_up(&qdio->req_q_wq);
356 
357 	qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
358 
359 	/* cleanup used outbound sbals */
360 	count = atomic_read(&qdio->req_q_free);
361 	if (count < QDIO_MAX_BUFFERS_PER_Q) {
362 		idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
363 		count = QDIO_MAX_BUFFERS_PER_Q - count;
364 		zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
365 	}
366 	qdio->req_q_idx = 0;
367 	atomic_set(&qdio->req_q_free, 0);
368 }
369 
370 /**
371  * zfcp_qdio_open - prepare and initialize response queue
372  * @qdio: pointer to struct zfcp_qdio
373  * Returns: 0 on success, otherwise -EIO
374  */
375 int zfcp_qdio_open(struct zfcp_qdio *qdio)
376 {
377 	struct qdio_buffer_element *sbale;
378 	struct qdio_initialize init_data;
379 	struct zfcp_adapter *adapter = qdio->adapter;
380 	struct ccw_device *cdev = adapter->ccw_device;
381 	struct qdio_ssqd_desc ssqd;
382 	int cc;
383 
384 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
385 		return -EIO;
386 
387 	atomic_andnot(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
388 			  &qdio->adapter->status);
389 
390 	zfcp_qdio_setup_init_data(&init_data, qdio);
391 
392 	if (qdio_establish(&init_data))
393 		goto failed_establish;
394 
395 	if (qdio_get_ssqd_desc(init_data.cdev, &ssqd))
396 		goto failed_qdio;
397 
398 	if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
399 		atomic_or(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
400 				&qdio->adapter->status);
401 
402 	if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
403 		atomic_or(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
404 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
405 	} else {
406 		atomic_andnot(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
407 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1;
408 	}
409 
410 	qdio->max_sbale_per_req =
411 		ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal
412 		- 2;
413 	if (qdio_activate(cdev))
414 		goto failed_qdio;
415 
416 	for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
417 		sbale = &(qdio->res_q[cc]->element[0]);
418 		sbale->length = 0;
419 		sbale->eflags = SBAL_EFLAGS_LAST_ENTRY;
420 		sbale->sflags = 0;
421 		sbale->addr = NULL;
422 	}
423 
424 	if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
425 		goto failed_qdio;
426 
427 	/* set index of first available SBALS / number of available SBALS */
428 	qdio->req_q_idx = 0;
429 	atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
430 	atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
431 
432 	if (adapter->scsi_host) {
433 		adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
434 		adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
435 	}
436 
437 	return 0;
438 
439 failed_qdio:
440 	qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
441 failed_establish:
442 	dev_err(&cdev->dev,
443 		"Setting up the QDIO connection to the FCP adapter failed\n");
444 	return -EIO;
445 }
446 
447 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
448 {
449 	if (!qdio)
450 		return;
451 
452 	if (qdio->adapter->ccw_device)
453 		qdio_free(qdio->adapter->ccw_device);
454 
455 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
456 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
457 	kfree(qdio);
458 }
459 
460 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
461 {
462 	struct zfcp_qdio *qdio;
463 
464 	qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
465 	if (!qdio)
466 		return -ENOMEM;
467 
468 	qdio->adapter = adapter;
469 
470 	if (zfcp_qdio_allocate(qdio)) {
471 		kfree(qdio);
472 		return -ENOMEM;
473 	}
474 
475 	spin_lock_init(&qdio->req_q_lock);
476 	spin_lock_init(&qdio->stat_lock);
477 
478 	adapter->qdio = qdio;
479 	return 0;
480 }
481 
482 /**
483  * zfcp_qdio_siosl - Trigger logging in FCP channel
484  * @adapter: The zfcp_adapter where to trigger logging
485  *
486  * Call the cio siosl function to trigger hardware logging.  This
487  * wrapper function sets a flag to ensure hardware logging is only
488  * triggered once before going through qdio shutdown.
489  *
490  * The triggers are always run from qdio tasklet context, so no
491  * additional synchronization is necessary.
492  */
493 void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
494 {
495 	int rc;
496 
497 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
498 		return;
499 
500 	rc = ccw_device_siosl(adapter->ccw_device);
501 	if (!rc)
502 		atomic_or(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
503 				&adapter->status);
504 }
505