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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Driver for the NXP SAA7164 PCIe bridge
4  *
5  *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
6  */
7 
8 #include <linux/wait.h>
9 
10 #include "saa7164.h"
11 
saa7164_cmd_alloc_seqno(struct saa7164_dev * dev)12 static int saa7164_cmd_alloc_seqno(struct saa7164_dev *dev)
13 {
14 	int i, ret = -1;
15 
16 	mutex_lock(&dev->lock);
17 	for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
18 		if (dev->cmds[i].inuse == 0) {
19 			dev->cmds[i].inuse = 1;
20 			dev->cmds[i].signalled = 0;
21 			dev->cmds[i].timeout = 0;
22 			ret = dev->cmds[i].seqno;
23 			break;
24 		}
25 	}
26 	mutex_unlock(&dev->lock);
27 
28 	return ret;
29 }
30 
saa7164_cmd_free_seqno(struct saa7164_dev * dev,u8 seqno)31 static void saa7164_cmd_free_seqno(struct saa7164_dev *dev, u8 seqno)
32 {
33 	mutex_lock(&dev->lock);
34 	if ((dev->cmds[seqno].inuse == 1) &&
35 		(dev->cmds[seqno].seqno == seqno)) {
36 		dev->cmds[seqno].inuse = 0;
37 		dev->cmds[seqno].signalled = 0;
38 		dev->cmds[seqno].timeout = 0;
39 	}
40 	mutex_unlock(&dev->lock);
41 }
42 
saa7164_cmd_timeout_seqno(struct saa7164_dev * dev,u8 seqno)43 static void saa7164_cmd_timeout_seqno(struct saa7164_dev *dev, u8 seqno)
44 {
45 	mutex_lock(&dev->lock);
46 	if ((dev->cmds[seqno].inuse == 1) &&
47 		(dev->cmds[seqno].seqno == seqno)) {
48 		dev->cmds[seqno].timeout = 1;
49 	}
50 	mutex_unlock(&dev->lock);
51 }
52 
saa7164_cmd_timeout_get(struct saa7164_dev * dev,u8 seqno)53 static u32 saa7164_cmd_timeout_get(struct saa7164_dev *dev, u8 seqno)
54 {
55 	int ret = 0;
56 
57 	mutex_lock(&dev->lock);
58 	if ((dev->cmds[seqno].inuse == 1) &&
59 		(dev->cmds[seqno].seqno == seqno)) {
60 		ret = dev->cmds[seqno].timeout;
61 	}
62 	mutex_unlock(&dev->lock);
63 
64 	return ret;
65 }
66 
67 /* Commands to the f/w get marshelled to/from this code then onto the PCI
68  * -bus/c running buffer. */
saa7164_irq_dequeue(struct saa7164_dev * dev)69 int saa7164_irq_dequeue(struct saa7164_dev *dev)
70 {
71 	int ret = SAA_OK, i = 0;
72 	u32 timeout;
73 	wait_queue_head_t *q = NULL;
74 	u8 tmp[512];
75 	dprintk(DBGLVL_CMD, "%s()\n", __func__);
76 
77 	/* While any outstand message on the bus exists... */
78 	do {
79 
80 		/* Peek the msg bus */
81 		struct tmComResInfo tRsp = { 0, 0, 0, 0, 0, 0 };
82 		ret = saa7164_bus_get(dev, &tRsp, NULL, 1);
83 		if (ret != SAA_OK)
84 			break;
85 
86 		q = &dev->cmds[tRsp.seqno].wait;
87 		timeout = saa7164_cmd_timeout_get(dev, tRsp.seqno);
88 		dprintk(DBGLVL_CMD, "%s() timeout = %d\n", __func__, timeout);
89 		if (!timeout) {
90 			dprintk(DBGLVL_CMD,
91 				"%s() signalled seqno(%d) (for dequeue)\n",
92 				__func__, tRsp.seqno);
93 			dev->cmds[tRsp.seqno].signalled = 1;
94 			wake_up(q);
95 		} else {
96 			printk(KERN_ERR
97 				"%s() found timed out command on the bus\n",
98 					__func__);
99 
100 			/* Clean the bus */
101 			ret = saa7164_bus_get(dev, &tRsp, &tmp, 0);
102 			printk(KERN_ERR "%s() ret = %x\n", __func__, ret);
103 			if (ret == SAA_ERR_EMPTY)
104 				/* Someone else already fetched the response */
105 				return SAA_OK;
106 
107 			if (ret != SAA_OK)
108 				return ret;
109 		}
110 
111 		/* It's unlikely to have more than 4 or 5 pending messages,
112 		 * ensure we exit at some point regardless.
113 		 */
114 	} while (i++ < 32);
115 
116 	return ret;
117 }
118 
119 /* Commands to the f/w get marshelled to/from this code then onto the PCI
120  * -bus/c running buffer. */
saa7164_cmd_dequeue(struct saa7164_dev * dev)121 static int saa7164_cmd_dequeue(struct saa7164_dev *dev)
122 {
123 	int ret;
124 	u32 timeout;
125 	wait_queue_head_t *q = NULL;
126 	u8 tmp[512];
127 	dprintk(DBGLVL_CMD, "%s()\n", __func__);
128 
129 	while (true) {
130 
131 		struct tmComResInfo tRsp = { 0, 0, 0, 0, 0, 0 };
132 		ret = saa7164_bus_get(dev, &tRsp, NULL, 1);
133 		if (ret == SAA_ERR_EMPTY)
134 			return SAA_OK;
135 
136 		if (ret != SAA_OK)
137 			return ret;
138 
139 		q = &dev->cmds[tRsp.seqno].wait;
140 		timeout = saa7164_cmd_timeout_get(dev, tRsp.seqno);
141 		dprintk(DBGLVL_CMD, "%s() timeout = %d\n", __func__, timeout);
142 		if (timeout) {
143 			printk(KERN_ERR "found timed out command on the bus\n");
144 
145 			/* Clean the bus */
146 			ret = saa7164_bus_get(dev, &tRsp, &tmp, 0);
147 			printk(KERN_ERR "ret = %x\n", ret);
148 			if (ret == SAA_ERR_EMPTY)
149 				/* Someone else already fetched the response */
150 				return SAA_OK;
151 
152 			if (ret != SAA_OK)
153 				return ret;
154 
155 			if (tRsp.flags & PVC_CMDFLAG_CONTINUE)
156 				printk(KERN_ERR "split response\n");
157 			else
158 				saa7164_cmd_free_seqno(dev, tRsp.seqno);
159 
160 			printk(KERN_ERR " timeout continue\n");
161 			continue;
162 		}
163 
164 		dprintk(DBGLVL_CMD, "%s() signalled seqno(%d) (for dequeue)\n",
165 			__func__, tRsp.seqno);
166 		dev->cmds[tRsp.seqno].signalled = 1;
167 		wake_up(q);
168 		return SAA_OK;
169 	}
170 }
171 
saa7164_cmd_set(struct saa7164_dev * dev,struct tmComResInfo * msg,void * buf)172 static int saa7164_cmd_set(struct saa7164_dev *dev, struct tmComResInfo *msg,
173 			   void *buf)
174 {
175 	struct tmComResBusInfo *bus = &dev->bus;
176 	u8 cmd_sent;
177 	u16 size, idx;
178 	u32 cmds;
179 	void *tmp;
180 	int ret = -1;
181 
182 	if (!msg) {
183 		printk(KERN_ERR "%s() !msg\n", __func__);
184 		return SAA_ERR_BAD_PARAMETER;
185 	}
186 
187 	mutex_lock(&dev->cmds[msg->id].lock);
188 
189 	size = msg->size;
190 	idx = 0;
191 	cmds = size / bus->m_wMaxReqSize;
192 	if (size % bus->m_wMaxReqSize == 0)
193 		cmds -= 1;
194 
195 	cmd_sent = 0;
196 
197 	/* Split the request into smaller chunks */
198 	for (idx = 0; idx < cmds; idx++) {
199 
200 		msg->flags |= SAA_CMDFLAG_CONTINUE;
201 		msg->size = bus->m_wMaxReqSize;
202 		tmp = buf + idx * bus->m_wMaxReqSize;
203 
204 		ret = saa7164_bus_set(dev, msg, tmp);
205 		if (ret != SAA_OK) {
206 			printk(KERN_ERR "%s() set failed %d\n", __func__, ret);
207 
208 			if (cmd_sent) {
209 				ret = SAA_ERR_BUSY;
210 				goto out;
211 			}
212 			ret = SAA_ERR_OVERFLOW;
213 			goto out;
214 		}
215 		cmd_sent = 1;
216 	}
217 
218 	/* If not the last command... */
219 	if (idx != 0)
220 		msg->flags &= ~SAA_CMDFLAG_CONTINUE;
221 
222 	msg->size = size - idx * bus->m_wMaxReqSize;
223 
224 	ret = saa7164_bus_set(dev, msg, buf + idx * bus->m_wMaxReqSize);
225 	if (ret != SAA_OK) {
226 		printk(KERN_ERR "%s() set last failed %d\n", __func__, ret);
227 
228 		if (cmd_sent) {
229 			ret = SAA_ERR_BUSY;
230 			goto out;
231 		}
232 		ret = SAA_ERR_OVERFLOW;
233 		goto out;
234 	}
235 	ret = SAA_OK;
236 
237 out:
238 	mutex_unlock(&dev->cmds[msg->id].lock);
239 	return ret;
240 }
241 
242 /* Wait for a signal event, without holding a mutex. Either return TIMEOUT if
243  * the event never occurred, or SAA_OK if it was signaled during the wait.
244  */
saa7164_cmd_wait(struct saa7164_dev * dev,u8 seqno)245 static int saa7164_cmd_wait(struct saa7164_dev *dev, u8 seqno)
246 {
247 	wait_queue_head_t *q = NULL;
248 	int ret = SAA_BUS_TIMEOUT;
249 	unsigned long stamp;
250 	int r;
251 
252 	if (saa_debug >= 4)
253 		saa7164_bus_dump(dev);
254 
255 	dprintk(DBGLVL_CMD, "%s(seqno=%d)\n", __func__, seqno);
256 
257 	mutex_lock(&dev->lock);
258 	if ((dev->cmds[seqno].inuse == 1) &&
259 		(dev->cmds[seqno].seqno == seqno)) {
260 		q = &dev->cmds[seqno].wait;
261 	}
262 	mutex_unlock(&dev->lock);
263 
264 	if (q) {
265 		/* If we haven't been signalled we need to wait */
266 		if (dev->cmds[seqno].signalled == 0) {
267 			stamp = jiffies;
268 			dprintk(DBGLVL_CMD,
269 				"%s(seqno=%d) Waiting (signalled=%d)\n",
270 				__func__, seqno, dev->cmds[seqno].signalled);
271 
272 			/* Wait for signalled to be flagged or timeout */
273 			/* In a highly stressed system this can easily extend
274 			 * into multiple seconds before the deferred worker
275 			 * is scheduled, and we're woken up via signal.
276 			 * We typically are signalled in < 50ms but it can
277 			 * take MUCH longer.
278 			 */
279 			wait_event_timeout(*q, dev->cmds[seqno].signalled,
280 				(HZ * waitsecs));
281 			r = time_before(jiffies, stamp + (HZ * waitsecs));
282 			if (r)
283 				ret = SAA_OK;
284 			else
285 				saa7164_cmd_timeout_seqno(dev, seqno);
286 
287 			dprintk(DBGLVL_CMD, "%s(seqno=%d) Waiting res = %d (signalled=%d)\n",
288 				__func__, seqno, r,
289 				dev->cmds[seqno].signalled);
290 		} else
291 			ret = SAA_OK;
292 	} else
293 		printk(KERN_ERR "%s(seqno=%d) seqno is invalid\n",
294 			__func__, seqno);
295 
296 	return ret;
297 }
298 
saa7164_cmd_signal(struct saa7164_dev * dev,u8 seqno)299 void saa7164_cmd_signal(struct saa7164_dev *dev, u8 seqno)
300 {
301 	int i;
302 	dprintk(DBGLVL_CMD, "%s()\n", __func__);
303 
304 	mutex_lock(&dev->lock);
305 	for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
306 		if (dev->cmds[i].inuse == 1) {
307 			dprintk(DBGLVL_CMD,
308 				"seqno %d inuse, sig = %d, t/out = %d\n",
309 				dev->cmds[i].seqno,
310 				dev->cmds[i].signalled,
311 				dev->cmds[i].timeout);
312 		}
313 	}
314 
315 	for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
316 		if ((dev->cmds[i].inuse == 1) && ((i == 0) ||
317 			(dev->cmds[i].signalled) || (dev->cmds[i].timeout))) {
318 			dprintk(DBGLVL_CMD, "%s(seqno=%d) calling wake_up\n",
319 				__func__, i);
320 			dev->cmds[i].signalled = 1;
321 			wake_up(&dev->cmds[i].wait);
322 		}
323 	}
324 	mutex_unlock(&dev->lock);
325 }
326 
saa7164_cmd_send(struct saa7164_dev * dev,u8 id,enum tmComResCmd command,u16 controlselector,u16 size,void * buf)327 int saa7164_cmd_send(struct saa7164_dev *dev, u8 id, enum tmComResCmd command,
328 	u16 controlselector, u16 size, void *buf)
329 {
330 	struct tmComResInfo command_t, *pcommand_t;
331 	struct tmComResInfo response_t, *presponse_t;
332 	u8 errdata[256];
333 	u16 resp_dsize;
334 	u16 data_recd;
335 	u32 loop;
336 	int ret;
337 	int safety = 0;
338 
339 	dprintk(DBGLVL_CMD, "%s(unitid = %s (%d) , command = 0x%x, sel = 0x%x)\n",
340 		__func__, saa7164_unitid_name(dev, id), id,
341 		command, controlselector);
342 
343 	if ((size == 0) || (buf == NULL)) {
344 		printk(KERN_ERR "%s() Invalid param\n", __func__);
345 		return SAA_ERR_BAD_PARAMETER;
346 	}
347 
348 	/* Prepare some basic command/response structures */
349 	memset(&command_t, 0, sizeof(command_t));
350 	memset(&response_t, 0, sizeof(response_t));
351 	pcommand_t = &command_t;
352 	presponse_t = &response_t;
353 	command_t.id = id;
354 	command_t.command = command;
355 	command_t.controlselector = controlselector;
356 	command_t.size = size;
357 
358 	/* Allocate a unique sequence number */
359 	ret = saa7164_cmd_alloc_seqno(dev);
360 	if (ret < 0) {
361 		printk(KERN_ERR "%s() No free sequences\n", __func__);
362 		ret = SAA_ERR_NO_RESOURCES;
363 		goto out;
364 	}
365 
366 	command_t.seqno = (u8)ret;
367 
368 	/* Send Command */
369 	resp_dsize = size;
370 	pcommand_t->size = size;
371 
372 	dprintk(DBGLVL_CMD, "%s() pcommand_t.seqno = %d\n",
373 		__func__, pcommand_t->seqno);
374 
375 	dprintk(DBGLVL_CMD, "%s() pcommand_t.size = %d\n",
376 		__func__, pcommand_t->size);
377 
378 	ret = saa7164_cmd_set(dev, pcommand_t, buf);
379 	if (ret != SAA_OK) {
380 		printk(KERN_ERR "%s() set command failed %d\n", __func__, ret);
381 
382 		if (ret != SAA_ERR_BUSY)
383 			saa7164_cmd_free_seqno(dev, pcommand_t->seqno);
384 		else
385 			/* Flag a timeout, because at least one
386 			 * command was sent */
387 			saa7164_cmd_timeout_seqno(dev, pcommand_t->seqno);
388 
389 		goto out;
390 	}
391 
392 	/* With split responses we have to collect the msgs piece by piece */
393 	data_recd = 0;
394 	loop = 1;
395 	while (loop) {
396 		dprintk(DBGLVL_CMD, "%s() loop\n", __func__);
397 
398 		ret = saa7164_cmd_wait(dev, pcommand_t->seqno);
399 		dprintk(DBGLVL_CMD, "%s() loop ret = %d\n", __func__, ret);
400 
401 		/* if power is down and this is not a power command ... */
402 
403 		if (ret == SAA_BUS_TIMEOUT) {
404 			printk(KERN_ERR "Event timed out\n");
405 			saa7164_cmd_timeout_seqno(dev, pcommand_t->seqno);
406 			return ret;
407 		}
408 
409 		if (ret != SAA_OK) {
410 			printk(KERN_ERR "spurious error\n");
411 			return ret;
412 		}
413 
414 		/* Peek response */
415 		ret = saa7164_bus_get(dev, presponse_t, NULL, 1);
416 		if (ret == SAA_ERR_EMPTY) {
417 			dprintk(4, "%s() SAA_ERR_EMPTY\n", __func__);
418 			continue;
419 		}
420 		if (ret != SAA_OK) {
421 			printk(KERN_ERR "peek failed\n");
422 			return ret;
423 		}
424 
425 		dprintk(DBGLVL_CMD, "%s() presponse_t->seqno = %d\n",
426 			__func__, presponse_t->seqno);
427 
428 		dprintk(DBGLVL_CMD, "%s() presponse_t->flags = 0x%x\n",
429 			__func__, presponse_t->flags);
430 
431 		dprintk(DBGLVL_CMD, "%s() presponse_t->size = %d\n",
432 			__func__, presponse_t->size);
433 
434 		/* Check if the response was for our command */
435 		if (presponse_t->seqno != pcommand_t->seqno) {
436 
437 			dprintk(DBGLVL_CMD,
438 				"wrong event: seqno = %d, expected seqno = %d, will dequeue regardless\n",
439 				presponse_t->seqno, pcommand_t->seqno);
440 
441 			ret = saa7164_cmd_dequeue(dev);
442 			if (ret != SAA_OK) {
443 				printk(KERN_ERR "dequeue failed, ret = %d\n",
444 					ret);
445 				if (safety++ > 16) {
446 					printk(KERN_ERR
447 					"dequeue exceeded, safety exit\n");
448 					return SAA_ERR_BUSY;
449 				}
450 			}
451 
452 			continue;
453 		}
454 
455 		if ((presponse_t->flags & PVC_RESPONSEFLAG_ERROR) != 0) {
456 
457 			memset(&errdata[0], 0, sizeof(errdata));
458 
459 			ret = saa7164_bus_get(dev, presponse_t, &errdata[0], 0);
460 			if (ret != SAA_OK) {
461 				printk(KERN_ERR "get error(2)\n");
462 				return ret;
463 			}
464 
465 			saa7164_cmd_free_seqno(dev, pcommand_t->seqno);
466 
467 			dprintk(DBGLVL_CMD, "%s() errdata %02x%02x%02x%02x\n",
468 				__func__, errdata[0], errdata[1], errdata[2],
469 				errdata[3]);
470 
471 			/* Map error codes */
472 			dprintk(DBGLVL_CMD, "%s() cmd, error code  = 0x%x\n",
473 				__func__, errdata[0]);
474 
475 			switch (errdata[0]) {
476 			case PVC_ERRORCODE_INVALID_COMMAND:
477 				dprintk(DBGLVL_CMD, "%s() INVALID_COMMAND\n",
478 					__func__);
479 				ret = SAA_ERR_INVALID_COMMAND;
480 				break;
481 			case PVC_ERRORCODE_INVALID_DATA:
482 				dprintk(DBGLVL_CMD, "%s() INVALID_DATA\n",
483 					__func__);
484 				ret = SAA_ERR_BAD_PARAMETER;
485 				break;
486 			case PVC_ERRORCODE_TIMEOUT:
487 				dprintk(DBGLVL_CMD, "%s() TIMEOUT\n", __func__);
488 				ret = SAA_ERR_TIMEOUT;
489 				break;
490 			case PVC_ERRORCODE_NAK:
491 				dprintk(DBGLVL_CMD, "%s() NAK\n", __func__);
492 				ret = SAA_ERR_NULL_PACKET;
493 				break;
494 			case PVC_ERRORCODE_UNKNOWN:
495 			case PVC_ERRORCODE_INVALID_CONTROL:
496 				dprintk(DBGLVL_CMD,
497 					"%s() UNKNOWN OR INVALID CONTROL\n",
498 					__func__);
499 				ret = SAA_ERR_NOT_SUPPORTED;
500 				break;
501 			default:
502 				dprintk(DBGLVL_CMD, "%s() UNKNOWN\n", __func__);
503 				ret = SAA_ERR_NOT_SUPPORTED;
504 			}
505 
506 			/* See of other commands are on the bus */
507 			if (saa7164_cmd_dequeue(dev) != SAA_OK)
508 				printk(KERN_ERR "dequeue(2) failed\n");
509 
510 			return ret;
511 		}
512 
513 		/* If response is invalid */
514 		if ((presponse_t->id != pcommand_t->id) ||
515 			(presponse_t->command != pcommand_t->command) ||
516 			(presponse_t->controlselector !=
517 				pcommand_t->controlselector) ||
518 			(((resp_dsize - data_recd) != presponse_t->size) &&
519 				!(presponse_t->flags & PVC_CMDFLAG_CONTINUE)) ||
520 			((resp_dsize - data_recd) < presponse_t->size)) {
521 
522 			/* Invalid */
523 			dprintk(DBGLVL_CMD, "%s() Invalid\n", __func__);
524 			ret = saa7164_bus_get(dev, presponse_t, NULL, 0);
525 			if (ret != SAA_OK) {
526 				printk(KERN_ERR "get failed\n");
527 				return ret;
528 			}
529 
530 			/* See of other commands are on the bus */
531 			if (saa7164_cmd_dequeue(dev) != SAA_OK)
532 				printk(KERN_ERR "dequeue(3) failed\n");
533 			continue;
534 		}
535 
536 		/* OK, now we're actually getting out correct response */
537 		ret = saa7164_bus_get(dev, presponse_t, buf + data_recd, 0);
538 		if (ret != SAA_OK) {
539 			printk(KERN_ERR "get failed\n");
540 			return ret;
541 		}
542 
543 		data_recd = presponse_t->size + data_recd;
544 		if (resp_dsize == data_recd) {
545 			dprintk(DBGLVL_CMD, "%s() Resp recd\n", __func__);
546 			break;
547 		}
548 
549 		/* See of other commands are on the bus */
550 		if (saa7164_cmd_dequeue(dev) != SAA_OK)
551 			printk(KERN_ERR "dequeue(3) failed\n");
552 
553 		continue;
554 
555 	} /* (loop) */
556 
557 	/* Release the sequence number allocation */
558 	saa7164_cmd_free_seqno(dev, pcommand_t->seqno);
559 
560 	/* if powerdown signal all pending commands */
561 
562 	dprintk(DBGLVL_CMD, "%s() Calling dequeue then exit\n", __func__);
563 
564 	/* See of other commands are on the bus */
565 	if (saa7164_cmd_dequeue(dev) != SAA_OK)
566 		printk(KERN_ERR "dequeue(4) failed\n");
567 
568 	ret = SAA_OK;
569 out:
570 	return ret;
571 }
572 
573