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 
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 
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 
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 
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. */
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. */
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 
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 	cmds = size / bus->m_wMaxReqSize;
191 	if (size % bus->m_wMaxReqSize == 0)
192 		cmds -= 1;
193 
194 	cmd_sent = 0;
195 
196 	/* Split the request into smaller chunks */
197 	for (idx = 0; idx < cmds; idx++) {
198 
199 		msg->flags |= SAA_CMDFLAG_CONTINUE;
200 		msg->size = bus->m_wMaxReqSize;
201 		tmp = buf + idx * bus->m_wMaxReqSize;
202 
203 		ret = saa7164_bus_set(dev, msg, tmp);
204 		if (ret != SAA_OK) {
205 			printk(KERN_ERR "%s() set failed %d\n", __func__, ret);
206 
207 			if (cmd_sent) {
208 				ret = SAA_ERR_BUSY;
209 				goto out;
210 			}
211 			ret = SAA_ERR_OVERFLOW;
212 			goto out;
213 		}
214 		cmd_sent = 1;
215 	}
216 
217 	/* If not the last command... */
218 	if (idx != 0)
219 		msg->flags &= ~SAA_CMDFLAG_CONTINUE;
220 
221 	msg->size = size - idx * bus->m_wMaxReqSize;
222 
223 	ret = saa7164_bus_set(dev, msg, buf + idx * bus->m_wMaxReqSize);
224 	if (ret != SAA_OK) {
225 		printk(KERN_ERR "%s() set last failed %d\n", __func__, ret);
226 
227 		if (cmd_sent) {
228 			ret = SAA_ERR_BUSY;
229 			goto out;
230 		}
231 		ret = SAA_ERR_OVERFLOW;
232 		goto out;
233 	}
234 	ret = SAA_OK;
235 
236 out:
237 	mutex_unlock(&dev->cmds[msg->id].lock);
238 	return ret;
239 }
240 
241 /* Wait for a signal event, without holding a mutex. Either return TIMEOUT if
242  * the event never occurred, or SAA_OK if it was signaled during the wait.
243  */
244 static int saa7164_cmd_wait(struct saa7164_dev *dev, u8 seqno)
245 {
246 	wait_queue_head_t *q = NULL;
247 	int ret = SAA_BUS_TIMEOUT;
248 	unsigned long stamp;
249 	int r;
250 
251 	if (saa_debug >= 4)
252 		saa7164_bus_dump(dev);
253 
254 	dprintk(DBGLVL_CMD, "%s(seqno=%d)\n", __func__, seqno);
255 
256 	mutex_lock(&dev->lock);
257 	if ((dev->cmds[seqno].inuse == 1) &&
258 		(dev->cmds[seqno].seqno == seqno)) {
259 		q = &dev->cmds[seqno].wait;
260 	}
261 	mutex_unlock(&dev->lock);
262 
263 	if (q) {
264 		/* If we haven't been signalled we need to wait */
265 		if (dev->cmds[seqno].signalled == 0) {
266 			stamp = jiffies;
267 			dprintk(DBGLVL_CMD,
268 				"%s(seqno=%d) Waiting (signalled=%d)\n",
269 				__func__, seqno, dev->cmds[seqno].signalled);
270 
271 			/* Wait for signalled to be flagged or timeout */
272 			/* In a highly stressed system this can easily extend
273 			 * into multiple seconds before the deferred worker
274 			 * is scheduled, and we're woken up via signal.
275 			 * We typically are signalled in < 50ms but it can
276 			 * take MUCH longer.
277 			 */
278 			wait_event_timeout(*q, dev->cmds[seqno].signalled,
279 				(HZ * waitsecs));
280 			r = time_before(jiffies, stamp + (HZ * waitsecs));
281 			if (r)
282 				ret = SAA_OK;
283 			else
284 				saa7164_cmd_timeout_seqno(dev, seqno);
285 
286 			dprintk(DBGLVL_CMD, "%s(seqno=%d) Waiting res = %d (signalled=%d)\n",
287 				__func__, seqno, r,
288 				dev->cmds[seqno].signalled);
289 		} else
290 			ret = SAA_OK;
291 	} else
292 		printk(KERN_ERR "%s(seqno=%d) seqno is invalid\n",
293 			__func__, seqno);
294 
295 	return ret;
296 }
297 
298 void saa7164_cmd_signal(struct saa7164_dev *dev, u8 seqno)
299 {
300 	int i;
301 	dprintk(DBGLVL_CMD, "%s()\n", __func__);
302 
303 	mutex_lock(&dev->lock);
304 	for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
305 		if (dev->cmds[i].inuse == 1) {
306 			dprintk(DBGLVL_CMD,
307 				"seqno %d inuse, sig = %d, t/out = %d\n",
308 				dev->cmds[i].seqno,
309 				dev->cmds[i].signalled,
310 				dev->cmds[i].timeout);
311 		}
312 	}
313 
314 	for (i = 0; i < SAA_CMD_MAX_MSG_UNITS; i++) {
315 		if ((dev->cmds[i].inuse == 1) && ((i == 0) ||
316 			(dev->cmds[i].signalled) || (dev->cmds[i].timeout))) {
317 			dprintk(DBGLVL_CMD, "%s(seqno=%d) calling wake_up\n",
318 				__func__, i);
319 			dev->cmds[i].signalled = 1;
320 			wake_up(&dev->cmds[i].wait);
321 		}
322 	}
323 	mutex_unlock(&dev->lock);
324 }
325 
326 int saa7164_cmd_send(struct saa7164_dev *dev, u8 id, enum tmComResCmd command,
327 	u16 controlselector, u16 size, void *buf)
328 {
329 	struct tmComResInfo command_t, *pcommand_t;
330 	struct tmComResInfo response_t, *presponse_t;
331 	u8 errdata[256];
332 	u16 resp_dsize;
333 	u16 data_recd;
334 	u32 loop;
335 	int ret;
336 	int safety = 0;
337 
338 	dprintk(DBGLVL_CMD, "%s(unitid = %s (%d) , command = 0x%x, sel = 0x%x)\n",
339 		__func__, saa7164_unitid_name(dev, id), id,
340 		command, controlselector);
341 
342 	if ((size == 0) || (buf == NULL)) {
343 		printk(KERN_ERR "%s() Invalid param\n", __func__);
344 		return SAA_ERR_BAD_PARAMETER;
345 	}
346 
347 	/* Prepare some basic command/response structures */
348 	memset(&command_t, 0, sizeof(command_t));
349 	memset(&response_t, 0, sizeof(response_t));
350 	pcommand_t = &command_t;
351 	presponse_t = &response_t;
352 	command_t.id = id;
353 	command_t.command = command;
354 	command_t.controlselector = controlselector;
355 	command_t.size = size;
356 
357 	/* Allocate a unique sequence number */
358 	ret = saa7164_cmd_alloc_seqno(dev);
359 	if (ret < 0) {
360 		printk(KERN_ERR "%s() No free sequences\n", __func__);
361 		ret = SAA_ERR_NO_RESOURCES;
362 		goto out;
363 	}
364 
365 	command_t.seqno = (u8)ret;
366 
367 	/* Send Command */
368 	resp_dsize = size;
369 	pcommand_t->size = size;
370 
371 	dprintk(DBGLVL_CMD, "%s() pcommand_t.seqno = %d\n",
372 		__func__, pcommand_t->seqno);
373 
374 	dprintk(DBGLVL_CMD, "%s() pcommand_t.size = %d\n",
375 		__func__, pcommand_t->size);
376 
377 	ret = saa7164_cmd_set(dev, pcommand_t, buf);
378 	if (ret != SAA_OK) {
379 		printk(KERN_ERR "%s() set command failed %d\n", __func__, ret);
380 
381 		if (ret != SAA_ERR_BUSY)
382 			saa7164_cmd_free_seqno(dev, pcommand_t->seqno);
383 		else
384 			/* Flag a timeout, because at least one
385 			 * command was sent */
386 			saa7164_cmd_timeout_seqno(dev, pcommand_t->seqno);
387 
388 		goto out;
389 	}
390 
391 	/* With split responses we have to collect the msgs piece by piece */
392 	data_recd = 0;
393 	loop = 1;
394 	while (loop) {
395 		dprintk(DBGLVL_CMD, "%s() loop\n", __func__);
396 
397 		ret = saa7164_cmd_wait(dev, pcommand_t->seqno);
398 		dprintk(DBGLVL_CMD, "%s() loop ret = %d\n", __func__, ret);
399 
400 		/* if power is down and this is not a power command ... */
401 
402 		if (ret == SAA_BUS_TIMEOUT) {
403 			printk(KERN_ERR "Event timed out\n");
404 			saa7164_cmd_timeout_seqno(dev, pcommand_t->seqno);
405 			return ret;
406 		}
407 
408 		if (ret != SAA_OK) {
409 			printk(KERN_ERR "spurious error\n");
410 			return ret;
411 		}
412 
413 		/* Peek response */
414 		ret = saa7164_bus_get(dev, presponse_t, NULL, 1);
415 		if (ret == SAA_ERR_EMPTY) {
416 			dprintk(4, "%s() SAA_ERR_EMPTY\n", __func__);
417 			continue;
418 		}
419 		if (ret != SAA_OK) {
420 			printk(KERN_ERR "peek failed\n");
421 			return ret;
422 		}
423 
424 		dprintk(DBGLVL_CMD, "%s() presponse_t->seqno = %d\n",
425 			__func__, presponse_t->seqno);
426 
427 		dprintk(DBGLVL_CMD, "%s() presponse_t->flags = 0x%x\n",
428 			__func__, presponse_t->flags);
429 
430 		dprintk(DBGLVL_CMD, "%s() presponse_t->size = %d\n",
431 			__func__, presponse_t->size);
432 
433 		/* Check if the response was for our command */
434 		if (presponse_t->seqno != pcommand_t->seqno) {
435 
436 			dprintk(DBGLVL_CMD,
437 				"wrong event: seqno = %d, expected seqno = %d, will dequeue regardless\n",
438 				presponse_t->seqno, pcommand_t->seqno);
439 
440 			ret = saa7164_cmd_dequeue(dev);
441 			if (ret != SAA_OK) {
442 				printk(KERN_ERR "dequeue failed, ret = %d\n",
443 					ret);
444 				if (safety++ > 16) {
445 					printk(KERN_ERR
446 					"dequeue exceeded, safety exit\n");
447 					return SAA_ERR_BUSY;
448 				}
449 			}
450 
451 			continue;
452 		}
453 
454 		if ((presponse_t->flags & PVC_RESPONSEFLAG_ERROR) != 0) {
455 
456 			memset(&errdata[0], 0, sizeof(errdata));
457 
458 			ret = saa7164_bus_get(dev, presponse_t, &errdata[0], 0);
459 			if (ret != SAA_OK) {
460 				printk(KERN_ERR "get error(2)\n");
461 				return ret;
462 			}
463 
464 			saa7164_cmd_free_seqno(dev, pcommand_t->seqno);
465 
466 			dprintk(DBGLVL_CMD, "%s() errdata %02x%02x%02x%02x\n",
467 				__func__, errdata[0], errdata[1], errdata[2],
468 				errdata[3]);
469 
470 			/* Map error codes */
471 			dprintk(DBGLVL_CMD, "%s() cmd, error code  = 0x%x\n",
472 				__func__, errdata[0]);
473 
474 			switch (errdata[0]) {
475 			case PVC_ERRORCODE_INVALID_COMMAND:
476 				dprintk(DBGLVL_CMD, "%s() INVALID_COMMAND\n",
477 					__func__);
478 				ret = SAA_ERR_INVALID_COMMAND;
479 				break;
480 			case PVC_ERRORCODE_INVALID_DATA:
481 				dprintk(DBGLVL_CMD, "%s() INVALID_DATA\n",
482 					__func__);
483 				ret = SAA_ERR_BAD_PARAMETER;
484 				break;
485 			case PVC_ERRORCODE_TIMEOUT:
486 				dprintk(DBGLVL_CMD, "%s() TIMEOUT\n", __func__);
487 				ret = SAA_ERR_TIMEOUT;
488 				break;
489 			case PVC_ERRORCODE_NAK:
490 				dprintk(DBGLVL_CMD, "%s() NAK\n", __func__);
491 				ret = SAA_ERR_NULL_PACKET;
492 				break;
493 			case PVC_ERRORCODE_UNKNOWN:
494 			case PVC_ERRORCODE_INVALID_CONTROL:
495 				dprintk(DBGLVL_CMD,
496 					"%s() UNKNOWN OR INVALID CONTROL\n",
497 					__func__);
498 				ret = SAA_ERR_NOT_SUPPORTED;
499 				break;
500 			default:
501 				dprintk(DBGLVL_CMD, "%s() UNKNOWN\n", __func__);
502 				ret = SAA_ERR_NOT_SUPPORTED;
503 			}
504 
505 			/* See of other commands are on the bus */
506 			if (saa7164_cmd_dequeue(dev) != SAA_OK)
507 				printk(KERN_ERR "dequeue(2) failed\n");
508 
509 			return ret;
510 		}
511 
512 		/* If response is invalid */
513 		if ((presponse_t->id != pcommand_t->id) ||
514 			(presponse_t->command != pcommand_t->command) ||
515 			(presponse_t->controlselector !=
516 				pcommand_t->controlselector) ||
517 			(((resp_dsize - data_recd) != presponse_t->size) &&
518 				!(presponse_t->flags & PVC_CMDFLAG_CONTINUE)) ||
519 			((resp_dsize - data_recd) < presponse_t->size)) {
520 
521 			/* Invalid */
522 			dprintk(DBGLVL_CMD, "%s() Invalid\n", __func__);
523 			ret = saa7164_bus_get(dev, presponse_t, NULL, 0);
524 			if (ret != SAA_OK) {
525 				printk(KERN_ERR "get failed\n");
526 				return ret;
527 			}
528 
529 			/* See of other commands are on the bus */
530 			if (saa7164_cmd_dequeue(dev) != SAA_OK)
531 				printk(KERN_ERR "dequeue(3) failed\n");
532 			continue;
533 		}
534 
535 		/* OK, now we're actually getting out correct response */
536 		ret = saa7164_bus_get(dev, presponse_t, buf + data_recd, 0);
537 		if (ret != SAA_OK) {
538 			printk(KERN_ERR "get failed\n");
539 			return ret;
540 		}
541 
542 		data_recd = presponse_t->size + data_recd;
543 		if (resp_dsize == data_recd) {
544 			dprintk(DBGLVL_CMD, "%s() Resp recd\n", __func__);
545 			break;
546 		}
547 
548 		/* See of other commands are on the bus */
549 		if (saa7164_cmd_dequeue(dev) != SAA_OK)
550 			printk(KERN_ERR "dequeue(3) failed\n");
551 	} /* (loop) */
552 
553 	/* Release the sequence number allocation */
554 	saa7164_cmd_free_seqno(dev, pcommand_t->seqno);
555 
556 	/* if powerdown signal all pending commands */
557 
558 	dprintk(DBGLVL_CMD, "%s() Calling dequeue then exit\n", __func__);
559 
560 	/* See of other commands are on the bus */
561 	if (saa7164_cmd_dequeue(dev) != SAA_OK)
562 		printk(KERN_ERR "dequeue(4) failed\n");
563 
564 	ret = SAA_OK;
565 out:
566 	return ret;
567 }
568 
569