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
12static 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
31static 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
43static 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
53static 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. */
69int 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. */
121static 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
172static 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
236out:
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 */
244static 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
298void 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
326int 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;
565out:
566	return ret;
567}
568
569