summaryrefslogtreecommitdiffstats
path: root/drivers/ieee1394/iso.c
blob: f26680ebef7cdcd5387627a98c79120d48dc77bb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
/*
 * IEEE 1394 for Linux
 *
 * kernel ISO transmission/reception
 *
 * Copyright (C) 2002 Maas Digital LLC
 *
 * This code is licensed under the GPL.  See the file COPYING in the root
 * directory of the kernel sources for details.
 */

#include <linux/slab.h>
#include <linux/sched.h>
#include "iso.h"

void hpsb_iso_stop(struct hpsb_iso *iso)
{
	if (!(iso->flags & HPSB_ISO_DRIVER_STARTED))
		return;

	iso->host->driver->isoctl(iso, iso->type == HPSB_ISO_XMIT ?
				  XMIT_STOP : RECV_STOP, 0);
	iso->flags &= ~HPSB_ISO_DRIVER_STARTED;
}

void hpsb_iso_shutdown(struct hpsb_iso *iso)
{
	if (iso->flags & HPSB_ISO_DRIVER_INIT) {
		hpsb_iso_stop(iso);
		iso->host->driver->isoctl(iso, iso->type == HPSB_ISO_XMIT ?
					  XMIT_SHUTDOWN : RECV_SHUTDOWN, 0);
		iso->flags &= ~HPSB_ISO_DRIVER_INIT;
	}

	dma_region_free(&iso->data_buf);
	kfree(iso);
}

static struct hpsb_iso *hpsb_iso_common_init(struct hpsb_host *host,
					     enum hpsb_iso_type type,
					     unsigned int data_buf_size,
					     unsigned int buf_packets,
					     int channel, int dma_mode,
					     int irq_interval,
					     void (*callback) (struct hpsb_iso
							       *))
{
	struct hpsb_iso *iso;
	int dma_direction;

	/* make sure driver supports the ISO API */
	if (!host->driver->isoctl) {
		printk(KERN_INFO
		       "ieee1394: host driver '%s' does not support the rawiso API\n",
		       host->driver->name);
		return NULL;
	}

	/* sanitize parameters */

	if (buf_packets < 2)
		buf_packets = 2;

	if ((dma_mode < HPSB_ISO_DMA_DEFAULT)
	    || (dma_mode > HPSB_ISO_DMA_PACKET_PER_BUFFER))
		dma_mode = HPSB_ISO_DMA_DEFAULT;

	if ((irq_interval < 0) || (irq_interval > buf_packets / 4))
		irq_interval = buf_packets / 4;
	if (irq_interval == 0)	/* really interrupt for each packet */
		irq_interval = 1;

	if (channel < -1 || channel >= 64)
		return NULL;

	/* channel = -1 is OK for multi-channel recv but not for xmit */
	if (type == HPSB_ISO_XMIT && channel < 0)
		return NULL;

	/* allocate and write the struct hpsb_iso */

	iso =
	    kmalloc(sizeof(*iso) +
		    buf_packets * sizeof(struct hpsb_iso_packet_info),
		    GFP_KERNEL);
	if (!iso)
		return NULL;

	iso->infos = (struct hpsb_iso_packet_info *)(iso + 1);

	iso->type = type;
	iso->host = host;
	iso->hostdata = NULL;
	iso->callback = callback;
	init_waitqueue_head(&iso->waitq);
	iso->channel = channel;
	iso->irq_interval = irq_interval;
	iso->dma_mode = dma_mode;
	dma_region_init(&iso->data_buf);
	iso->buf_size = PAGE_ALIGN(data_buf_size);
	iso->buf_packets = buf_packets;
	iso->pkt_dma = 0;
	iso->first_packet = 0;
	spin_lock_init(&iso->lock);

	if (iso->type == HPSB_ISO_XMIT) {
		iso->n_ready_packets = iso->buf_packets;
		dma_direction = PCI_DMA_TODEVICE;
	} else {
		iso->n_ready_packets = 0;
		dma_direction = PCI_DMA_FROMDEVICE;
	}

	atomic_set(&iso->overflows, 0);
	iso->bytes_discarded = 0;
	iso->flags = 0;
	iso->prebuffer = 0;

	/* allocate the packet buffer */
	if (dma_region_alloc
	    (&iso->data_buf, iso->buf_size, host->pdev, dma_direction))
		goto err;

	return iso;

      err:
	hpsb_iso_shutdown(iso);
	return NULL;
}

int hpsb_iso_n_ready(struct hpsb_iso *iso)
{
	unsigned long flags;
	int val;

	spin_lock_irqsave(&iso->lock, flags);
	val = iso->n_ready_packets;
	spin_unlock_irqrestore(&iso->lock, flags);

	return val;
}

struct hpsb_iso *hpsb_iso_xmit_init(struct hpsb_host *host,
				    unsigned int data_buf_size,
				    unsigned int buf_packets,
				    int channel,
				    int speed,
				    int irq_interval,
				    void (*callback) (struct hpsb_iso *))
{
	struct hpsb_iso *iso = hpsb_iso_common_init(host, HPSB_ISO_XMIT,
						    data_buf_size, buf_packets,
						    channel,
						    HPSB_ISO_DMA_DEFAULT,
						    irq_interval, callback);
	if (!iso)
		return NULL;

	iso->speed = speed;

	/* tell the driver to start working */
	if (host->driver->isoctl(iso, XMIT_INIT, 0))
		goto err;

	iso->flags |= HPSB_ISO_DRIVER_INIT;
	return iso;

      err:
	hpsb_iso_shutdown(iso);
	return NULL;
}

struct hpsb_iso *hpsb_iso_recv_init(struct hpsb_host *host,
				    unsigned int data_buf_size,
				    unsigned int buf_packets,
				    int channel,
				    int dma_mode,
				    int irq_interval,
				    void (*callback) (struct hpsb_iso *))
{
	struct hpsb_iso *iso = hpsb_iso_common_init(host, HPSB_ISO_RECV,
						    data_buf_size, buf_packets,
						    channel, dma_mode,
						    irq_interval, callback);
	if (!iso)
		return NULL;

	/* tell the driver to start working */
	if (host->driver->isoctl(iso, RECV_INIT, 0))
		goto err;

	iso->flags |= HPSB_ISO_DRIVER_INIT;
	return iso;

      err:
	hpsb_iso_shutdown(iso);
	return NULL;
}

int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel)
{
	if (iso->type != HPSB_ISO_RECV || iso->channel != -1 || channel >= 64)
		return -EINVAL;
	return iso->host->driver->isoctl(iso, RECV_LISTEN_CHANNEL, channel);
}

int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel)
{
	if (iso->type != HPSB_ISO_RECV || iso->channel != -1 || channel >= 64)
		return -EINVAL;
	return iso->host->driver->isoctl(iso, RECV_UNLISTEN_CHANNEL, channel);
}

int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask)
{
	if (iso->type != HPSB_ISO_RECV || iso->channel != -1)
		return -EINVAL;
	return iso->host->driver->isoctl(iso, RECV_SET_CHANNEL_MASK,
					 (unsigned long)&mask);
}

int hpsb_iso_recv_flush(struct hpsb_iso *iso)
{
	if (iso->type != HPSB_ISO_RECV)
		return -EINVAL;
	return iso->host->driver->isoctl(iso, RECV_FLUSH, 0);
}

static int do_iso_xmit_start(struct hpsb_iso *iso, int cycle)
{
	int retval = iso->host->driver->isoctl(iso, XMIT_START, cycle);
	if (retval)
		return retval;

	iso->flags |= HPSB_ISO_DRIVER_STARTED;
	return retval;
}

int hpsb_iso_xmit_start(struct hpsb_iso *iso, int cycle, int prebuffer)
{
	if (iso->type != HPSB_ISO_XMIT)
		return -1;

	if (iso->flags & HPSB_ISO_DRIVER_STARTED)
		return 0;

	if (cycle < -1)
		cycle = -1;
	else if (cycle >= 8000)
		cycle %= 8000;

	iso->xmit_cycle = cycle;

	if (prebuffer < 0)
		prebuffer = iso->buf_packets - 1;
	else if (prebuffer == 0)
		prebuffer = 1;

	if (prebuffer >= iso->buf_packets)
		prebuffer = iso->buf_packets - 1;

	iso->prebuffer = prebuffer;

	/* remember the starting cycle; DMA will commence from xmit_queue_packets()
	   once enough packets have been buffered */
	iso->start_cycle = cycle;

	return 0;
}

int hpsb_iso_recv_start(struct hpsb_iso *iso, int cycle, int tag_mask, int sync)
{
	int retval = 0;
	int isoctl_args[3];

	if (iso->type != HPSB_ISO_RECV)
		return -1;

	if (iso->flags & HPSB_ISO_DRIVER_STARTED)
		return 0;

	if (cycle < -1)
		cycle = -1;
	else if (cycle >= 8000)
		cycle %= 8000;

	isoctl_args[0] = cycle;

	if (tag_mask < 0)
		/* match all tags */
		tag_mask = 0xF;
	isoctl_args[1] = tag_mask;

	isoctl_args[2] = sync;

	retval =
	    iso->host->driver->isoctl(iso, RECV_START,
				      (unsigned long)&isoctl_args[0]);
	if (retval)
		return retval;

	iso->flags |= HPSB_ISO_DRIVER_STARTED;
	return retval;
}

/* check to make sure the user has not supplied bogus values of offset/len
   that would cause the kernel to access memory outside the buffer */

static int hpsb_iso_check_offset_len(struct hpsb_iso *iso,
				     unsigned int offset, unsigned short len,
				     unsigned int *out_offset,
				     unsigned short *out_len)
{
	if (offset >= iso->buf_size)
		return -EFAULT;

	/* make sure the packet does not go beyond the end of the buffer */
	if (offset + len > iso->buf_size)
		return -EFAULT;

	/* check for wrap-around */
	if (offset + len < offset)
		return -EFAULT;

	/* now we can trust 'offset' and 'length' */
	*out_offset = offset;
	*out_len = len;

	return 0;
}

int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
			       u8 tag, u8 sy)
{
	struct hpsb_iso_packet_info *info;
	unsigned long flags;
	int rv;

	if (iso->type != HPSB_ISO_XMIT)
		return -EINVAL;

	/* is there space in the buffer? */
	if (iso->n_ready_packets <= 0) {
		return -EBUSY;
	}

	info = &iso->infos[iso->first_packet];

	/* check for bogus offset/length */
	if (hpsb_iso_check_offset_len
	    (iso, offset, len, &info->offset, &info->len))
		return -EFAULT;

	info->tag = tag;
	info->sy = sy;

	spin_lock_irqsave(&iso->lock, flags);

	rv = iso->host->driver->isoctl(iso, XMIT_QUEUE, (unsigned long)info);
	if (rv)
		goto out;

	/* increment cursors */
	iso->first_packet = (iso->first_packet + 1) % iso->buf_packets;
	iso->xmit_cycle = (iso->xmit_cycle + 1) % 8000;
	iso->n_ready_packets--;

	if (iso->prebuffer != 0) {
		iso->prebuffer--;
		if (iso->prebuffer <= 0) {
			iso->prebuffer = 0;
			rv = do_iso_xmit_start(iso, iso->start_cycle);
		}
	}

      out:
	spin_unlock_irqrestore(&iso->lock, flags);
	return rv;
}

int hpsb_iso_xmit_sync(struct hpsb_iso *iso)
{
	if (iso->type != HPSB_ISO_XMIT)
		return -EINVAL;

	return wait_event_interruptible(iso->waitq,
					hpsb_iso_n_ready(iso) ==
					iso->buf_packets);
}

void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error)
{
	unsigned long flags;
	spin_lock_irqsave(&iso->lock, flags);

	/* predict the cycle of the next packet to be queued */

	/* jump ahead by the number of packets that are already buffered */
	cycle += iso->buf_packets - iso->n_ready_packets;
	cycle %= 8000;

	iso->xmit_cycle = cycle;
	iso->n_ready_packets++;
	iso->pkt_dma = (iso->pkt_dma + 1) % iso->buf_packets;

	if (iso->n_ready_packets == iso->buf_packets || error != 0) {
		/* the buffer has run empty! */
		atomic_inc(&iso->overflows);
	}

	spin_unlock_irqrestore(&iso->lock, flags);
}

void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
			      u16 total_len, u16 cycle, u8 channel, u8 tag,
			      u8 sy)
{
	unsigned long flags;
	spin_lock_irqsave(&iso->lock, flags);

	if (iso->n_ready_packets == iso->buf_packets) {
		/* overflow! */
		atomic_inc(&iso->overflows);
		/* Record size of this discarded packet */
		iso->bytes_discarded += total_len;
	} else {
		struct hpsb_iso_packet_info *info = &iso->infos[iso->pkt_dma];
		info->offset = offset;
		info->len = len;
		info->total_len = total_len;
		info->cycle = cycle;
		info->channel = channel;
		info->tag = tag;
		info->sy = sy;

		iso->pkt_dma = (iso->pkt_dma + 1) % iso->buf_packets;
		iso->n_ready_packets++;
	}

	spin_unlock_irqrestore(&iso->lock, flags);
}

int hpsb_iso_recv_release_packets(struct hpsb_iso *iso, unsigned int n_packets)
{
	unsigned long flags;
	unsigned int i;
	int rv = 0;

	if (iso->type != HPSB_ISO_RECV)
		return -1;

	spin_lock_irqsave(&iso->lock, flags);
	for (i = 0; i < n_packets; i++) {
		rv = iso->host->driver->isoctl(iso, RECV_RELEASE,
					       (unsigned long)&iso->infos[iso->
									  first_packet]);
		if (rv)
			break;

		iso->first_packet = (iso->first_packet + 1) % iso->buf_packets;
		iso->n_ready_packets--;

		/* release memory from packets discarded when queue was full  */
		if (iso->n_ready_packets == 0) {	/* Release only after all prior packets handled */
			if (iso->bytes_discarded != 0) {
				struct hpsb_iso_packet_info inf;
				inf.total_len = iso->bytes_discarded;
				iso->host->driver->isoctl(iso, RECV_RELEASE,
							  (unsigned long)&inf);
				iso->bytes_discarded = 0;
			}
		}
	}
	spin_unlock_irqrestore(&iso->lock, flags);
	return rv;
}

void hpsb_iso_wake(struct hpsb_iso *iso)
{
	wake_up_interruptible(&iso->waitq);

	if (iso->callback)
		iso->callback(iso);
}
OpenPOWER on IntegriCloud