xref: /openbmc/linux/drivers/s390/scsi/zfcp_qdio.c (revision 15e3ae36)
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 = 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_phys(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  * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data
282  * @qdio: pointer to struct zfcp_qdio
283  * Returns: -ENOMEM on memory allocation error or return value from
284  *          qdio_allocate
285  */
286 static int zfcp_qdio_allocate(struct zfcp_qdio *qdio)
287 {
288 	int ret;
289 
290 	ret = qdio_alloc_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
291 	if (ret)
292 		return -ENOMEM;
293 
294 	ret = qdio_alloc_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
295 	if (ret)
296 		goto free_req_q;
297 
298 	init_waitqueue_head(&qdio->req_q_wq);
299 
300 	ret = qdio_allocate(qdio->adapter->ccw_device, 1, 1);
301 	if (ret)
302 		goto free_res_q;
303 
304 	return 0;
305 
306 free_res_q:
307 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
308 free_req_q:
309 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
310 	return ret;
311 }
312 
313 /**
314  * zfcp_close_qdio - close qdio queues for an adapter
315  * @qdio: pointer to structure zfcp_qdio
316  */
317 void zfcp_qdio_close(struct zfcp_qdio *qdio)
318 {
319 	struct zfcp_adapter *adapter = qdio->adapter;
320 	int idx, count;
321 
322 	if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP))
323 		return;
324 
325 	/* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
326 	spin_lock_irq(&qdio->req_q_lock);
327 	atomic_andnot(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
328 	spin_unlock_irq(&qdio->req_q_lock);
329 
330 	wake_up(&qdio->req_q_wq);
331 
332 	qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR);
333 
334 	/* cleanup used outbound sbals */
335 	count = atomic_read(&qdio->req_q_free);
336 	if (count < QDIO_MAX_BUFFERS_PER_Q) {
337 		idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q;
338 		count = QDIO_MAX_BUFFERS_PER_Q - count;
339 		zfcp_qdio_zero_sbals(qdio->req_q, idx, count);
340 	}
341 	qdio->req_q_idx = 0;
342 	atomic_set(&qdio->req_q_free, 0);
343 }
344 
345 /**
346  * zfcp_qdio_open - prepare and initialize response queue
347  * @qdio: pointer to struct zfcp_qdio
348  * Returns: 0 on success, otherwise -EIO
349  */
350 int zfcp_qdio_open(struct zfcp_qdio *qdio)
351 {
352 	struct qdio_buffer **input_sbals[1] = {qdio->res_q};
353 	struct qdio_buffer **output_sbals[1] = {qdio->req_q};
354 	struct qdio_buffer_element *sbale;
355 	struct qdio_initialize init_data = {0};
356 	struct zfcp_adapter *adapter = qdio->adapter;
357 	struct ccw_device *cdev = adapter->ccw_device;
358 	struct qdio_ssqd_desc ssqd;
359 	int cc;
360 
361 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)
362 		return -EIO;
363 
364 	atomic_andnot(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
365 			  &qdio->adapter->status);
366 
367 	init_data.q_format = QDIO_ZFCP_QFMT;
368 	memcpy(init_data.adapter_name, dev_name(&cdev->dev), 8);
369 	ASCEBC(init_data.adapter_name, 8);
370 	init_data.qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV;
371 	if (enable_multibuffer)
372 		init_data.qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE;
373 	init_data.no_input_qs = 1;
374 	init_data.no_output_qs = 1;
375 	init_data.input_handler = zfcp_qdio_int_resp;
376 	init_data.output_handler = zfcp_qdio_int_req;
377 	init_data.int_parm = (unsigned long) qdio;
378 	init_data.input_sbal_addr_array = input_sbals;
379 	init_data.output_sbal_addr_array = output_sbals;
380 	init_data.scan_threshold =
381 		QDIO_MAX_BUFFERS_PER_Q - ZFCP_QDIO_MAX_SBALS_PER_REQ * 2;
382 
383 	if (qdio_establish(cdev, &init_data))
384 		goto failed_establish;
385 
386 	if (qdio_get_ssqd_desc(cdev, &ssqd))
387 		goto failed_qdio;
388 
389 	if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED)
390 		atomic_or(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED,
391 				&qdio->adapter->status);
392 
393 	if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) {
394 		atomic_or(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
395 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER;
396 	} else {
397 		atomic_andnot(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status);
398 		qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1;
399 	}
400 
401 	qdio->max_sbale_per_req =
402 		ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal
403 		- 2;
404 	if (qdio_activate(cdev))
405 		goto failed_qdio;
406 
407 	for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) {
408 		sbale = &(qdio->res_q[cc]->element[0]);
409 		sbale->length = 0;
410 		sbale->eflags = SBAL_EFLAGS_LAST_ENTRY;
411 		sbale->sflags = 0;
412 		sbale->addr = 0;
413 	}
414 
415 	if (do_QDIO(cdev, QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q))
416 		goto failed_qdio;
417 
418 	/* set index of first available SBALS / number of available SBALS */
419 	qdio->req_q_idx = 0;
420 	atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q);
421 	atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status);
422 
423 	if (adapter->scsi_host) {
424 		adapter->scsi_host->sg_tablesize = qdio->max_sbale_per_req;
425 		adapter->scsi_host->max_sectors = qdio->max_sbale_per_req * 8;
426 	}
427 
428 	return 0;
429 
430 failed_qdio:
431 	qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
432 failed_establish:
433 	dev_err(&cdev->dev,
434 		"Setting up the QDIO connection to the FCP adapter failed\n");
435 	return -EIO;
436 }
437 
438 void zfcp_qdio_destroy(struct zfcp_qdio *qdio)
439 {
440 	if (!qdio)
441 		return;
442 
443 	if (qdio->adapter->ccw_device)
444 		qdio_free(qdio->adapter->ccw_device);
445 
446 	qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q);
447 	qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q);
448 	kfree(qdio);
449 }
450 
451 int zfcp_qdio_setup(struct zfcp_adapter *adapter)
452 {
453 	struct zfcp_qdio *qdio;
454 
455 	qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL);
456 	if (!qdio)
457 		return -ENOMEM;
458 
459 	qdio->adapter = adapter;
460 
461 	if (zfcp_qdio_allocate(qdio)) {
462 		kfree(qdio);
463 		return -ENOMEM;
464 	}
465 
466 	spin_lock_init(&qdio->req_q_lock);
467 	spin_lock_init(&qdio->stat_lock);
468 
469 	adapter->qdio = qdio;
470 	return 0;
471 }
472 
473 /**
474  * zfcp_qdio_siosl - Trigger logging in FCP channel
475  * @adapter: The zfcp_adapter where to trigger logging
476  *
477  * Call the cio siosl function to trigger hardware logging.  This
478  * wrapper function sets a flag to ensure hardware logging is only
479  * triggered once before going through qdio shutdown.
480  *
481  * The triggers are always run from qdio tasklet context, so no
482  * additional synchronization is necessary.
483  */
484 void zfcp_qdio_siosl(struct zfcp_adapter *adapter)
485 {
486 	int rc;
487 
488 	if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED)
489 		return;
490 
491 	rc = ccw_device_siosl(adapter->ccw_device);
492 	if (!rc)
493 		atomic_or(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED,
494 				&adapter->status);
495 }
496