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	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
237out:
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 */
245static 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
299void 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
327int 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;
569out:
570	return ret;
571}
572
573