drivers/ieee1394/iso.c

   1 /*
   2  * IEEE 1394 for Linux
   3  *
   4  * kernel ISO transmission/reception
   5  *
   6  * Copyright (C) 2002 Maas Digital LLC
   7  *
   8  * This code is licensed under the GPL.  See the file COPYING in the root
   9  * directory of the kernel sources for details.
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/sched.h>
  14 #include "iso.h"
  15
  16 void hpsb_iso_stop(struct hpsb_iso *iso)
  17 {
  18         if (!(iso->flags & HPSB_ISO_DRIVER_STARTED))
  19                 return;
  20
  21         iso->host->driver->isoctl(iso, iso->type == HPSB_ISO_XMIT ?
  22                                   XMIT_STOP : RECV_STOP, 0);
  23         iso->flags &= ~HPSB_ISO_DRIVER_STARTED;
  24 }
  25
  26 void hpsb_iso_shutdown(struct hpsb_iso *iso)
  27 {
  28         if (iso->flags & HPSB_ISO_DRIVER_INIT) {
  29                 hpsb_iso_stop(iso);
  30                 iso->host->driver->isoctl(iso, iso->type == HPSB_ISO_XMIT ?
  31                                           XMIT_SHUTDOWN : RECV_SHUTDOWN, 0);
  32                 iso->flags &= ~HPSB_ISO_DRIVER_INIT;
  33         }
  34
  35         dma_region_free(&iso->data_buf);
  36         kfree(iso);
  37 }
  38
  39 static struct hpsb_iso *hpsb_iso_common_init(struct hpsb_host *host,
  40                                              enum hpsb_iso_type type,
  41                                              unsigned int data_buf_size,
  42                                              unsigned int buf_packets,
  43                                              int channel, int dma_mode,
  44                                              int irq_interval,
  45                                              void (*callback) (struct hpsb_iso
  46                                                                *))
  47 {
  48         struct hpsb_iso *iso;
  49         int dma_direction;
  50
  51         /* make sure driver supports the ISO API */
  52         if (!host->driver->isoctl) {
  53                 printk(KERN_INFO
  54                        "ieee1394: host driver '%s' does not support the rawiso API\n",
  55                        host->driver->name);
  56                 return NULL;
  57         }
  58
  59         /* sanitize parameters */
  60
  61         if (buf_packets < 2)
  62                 buf_packets = 2;
  63
  64         if ((dma_mode < HPSB_ISO_DMA_DEFAULT)
  65             || (dma_mode > HPSB_ISO_DMA_PACKET_PER_BUFFER))
  66                 dma_mode = HPSB_ISO_DMA_DEFAULT;
  67
  68         if ((irq_interval < 0) || (irq_interval > buf_packets / 4))
  69                 irq_interval = buf_packets / 4;
  70         if (irq_interval == 0)  /* really interrupt for each packet */
  71                 irq_interval = 1;
  72
  73         if (channel < -1 || channel >= 64)
  74                 return NULL;
  75
  76         /* channel = -1 is OK for multi-channel recv but not for xmit */
  77         if (type == HPSB_ISO_XMIT && channel < 0)
  78                 return NULL;
  79
  80         /* allocate and write the struct hpsb_iso */
  81
  82         iso =
  83             kmalloc(sizeof(*iso) +
  84                     buf_packets * sizeof(struct hpsb_iso_packet_info),
  85                     GFP_KERNEL);
  86         if (!iso)
  87                 return NULL;
  88
  89         iso->infos = (struct hpsb_iso_packet_info *)(iso + 1);
  90
  91         iso->type = type;
  92         iso->host = host;
  93         iso->hostdata = NULL;
  94         iso->callback = callback;
  95         init_waitqueue_head(&iso->waitq);
  96         iso->channel = channel;
  97         iso->irq_interval = irq_interval;
  98         iso->dma_mode = dma_mode;
  99         dma_region_init(&iso->data_buf);
 100         iso->buf_size = PAGE_ALIGN(data_buf_size);
 101         iso->buf_packets = buf_packets;
 102         iso->pkt_dma = 0;
 103         iso->first_packet = 0;
 104         spin_lock_init(&iso->lock);
 105
 106         if (iso->type == HPSB_ISO_XMIT) {
 107                 iso->n_ready_packets = iso->buf_packets;
 108                 dma_direction = PCI_DMA_TODEVICE;
 109         } else {
 110                 iso->n_ready_packets = 0;
 111                 dma_direction = PCI_DMA_FROMDEVICE;
 112         }
 113
 114         atomic_set(&iso->overflows, 0);
 115         iso->bytes_discarded = 0;
 116         iso->flags = 0;
 117         iso->prebuffer = 0;
 118
 119         /* allocate the packet buffer */
 120         if (dma_region_alloc
 121             (&iso->data_buf, iso->buf_size, host->pdev, dma_direction))
 122                 goto err;
 123
 124         return iso;
 125
 126       err:
 127         hpsb_iso_shutdown(iso);
 128         return NULL;
 129 }
 130
 131 int hpsb_iso_n_ready(struct hpsb_iso *iso)
 132 {
 133         unsigned long flags;
 134         int val;
 135
 136         spin_lock_irqsave(&iso->lock, flags);
 137         val = iso->n_ready_packets;
 138         spin_unlock_irqrestore(&iso->lock, flags);
 139
 140         return val;
 141 }
 142
 143 struct hpsb_iso *hpsb_iso_xmit_init(struct hpsb_host *host,
 144                                     unsigned int data_buf_size,
 145                                     unsigned int buf_packets,
 146                                     int channel,
 147                                     int speed,
 148                                     int irq_interval,
 149                                     void (*callback) (struct hpsb_iso *))
 150 {
 151         struct hpsb_iso *iso = hpsb_iso_common_init(host, HPSB_ISO_XMIT,
 152                                                     data_buf_size, buf_packets,
 153                                                     channel,
 154                                                     HPSB_ISO_DMA_DEFAULT,
 155                                                     irq_interval, callback);
 156         if (!iso)
 157                 return NULL;
 158
 159         iso->speed = speed;
 160
 161         /* tell the driver to start working */
 162         if (host->driver->isoctl(iso, XMIT_INIT, 0))
 163                 goto err;
 164
 165         iso->flags |= HPSB_ISO_DRIVER_INIT;
 166         return iso;
 167
 168       err:
 169         hpsb_iso_shutdown(iso);
 170         return NULL;
 171 }
 172
 173 struct hpsb_iso *hpsb_iso_recv_init(struct hpsb_host *host,
 174                                     unsigned int data_buf_size,
 175                                     unsigned int buf_packets,
 176                                     int channel,
 177                                     int dma_mode,
 178                                     int irq_interval,
 179                                     void (*callback) (struct hpsb_iso *))
 180 {
 181         struct hpsb_iso *iso = hpsb_iso_common_init(host, HPSB_ISO_RECV,
 182                                                     data_buf_size, buf_packets,
 183                                                     channel, dma_mode,
 184                                                     irq_interval, callback);
 185         if (!iso)
 186                 return NULL;
 187
 188         /* tell the driver to start working */
 189         if (host->driver->isoctl(iso, RECV_INIT, 0))
 190                 goto err;
 191
 192         iso->flags |= HPSB_ISO_DRIVER_INIT;
 193         return iso;
 194
 195       err:
 196         hpsb_iso_shutdown(iso);
 197         return NULL;
 198 }
 199
 200 int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel)
 201 {
 202         if (iso->type != HPSB_ISO_RECV || iso->channel != -1 || channel >= 64)
 203                 return -EINVAL;
 204         return iso->host->driver->isoctl(iso, RECV_LISTEN_CHANNEL, channel);
 205 }
 206
 207 int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel)
 208 {
 209         if (iso->type != HPSB_ISO_RECV || iso->channel != -1 || channel >= 64)
 210                 return -EINVAL;
 211         return iso->host->driver->isoctl(iso, RECV_UNLISTEN_CHANNEL, channel);
 212 }
 213
 214 int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask)
 215 {
 216         if (iso->type != HPSB_ISO_RECV || iso->channel != -1)
 217                 return -EINVAL;
 218         return iso->host->driver->isoctl(iso, RECV_SET_CHANNEL_MASK,
 219                                          (unsigned long)&mask);
 220 }
 221
 222 int hpsb_iso_recv_flush(struct hpsb_iso *iso)
 223 {
 224         if (iso->type != HPSB_ISO_RECV)
 225                 return -EINVAL;
 226         return iso->host->driver->isoctl(iso, RECV_FLUSH, 0);
 227 }
 228
 229 static int do_iso_xmit_start(struct hpsb_iso *iso, int cycle)
 230 {
 231         int retval = iso->host->driver->isoctl(iso, XMIT_START, cycle);
 232         if (retval)
 233                 return retval;
 234
 235         iso->flags |= HPSB_ISO_DRIVER_STARTED;
 236         return retval;
 237 }
 238
 239 int hpsb_iso_xmit_start(struct hpsb_iso *iso, int cycle, int prebuffer)
 240 {
 241         if (iso->type != HPSB_ISO_XMIT)
 242                 return -1;
 243
 244         if (iso->flags & HPSB_ISO_DRIVER_STARTED)
 245                 return 0;
 246
 247         if (cycle < -1)
 248                 cycle = -1;
 249         else if (cycle >= 8000)
 250                 cycle %= 8000;
 251
 252         iso->xmit_cycle = cycle;
 253
 254         if (prebuffer < 0)
 255                 prebuffer = iso->buf_packets - 1;
 256         else if (prebuffer == 0)
 257                 prebuffer = 1;
 258
 259         if (prebuffer >= iso->buf_packets)
 260                 prebuffer = iso->buf_packets - 1;
 261
 262         iso->prebuffer = prebuffer;
 263
 264         /* remember the starting cycle; DMA will commence from xmit_queue_packets()
 265            once enough packets have been buffered */
 266         iso->start_cycle = cycle;
 267
 268         return 0;
 269 }
 270
 271 int hpsb_iso_recv_start(struct hpsb_iso *iso, int cycle, int tag_mask, int sync)
 272 {
 273         int retval = 0;
 274         int isoctl_args[3];
 275
 276         if (iso->type != HPSB_ISO_RECV)
 277                 return -1;
 278
 279         if (iso->flags & HPSB_ISO_DRIVER_STARTED)
 280                 return 0;
 281
 282         if (cycle < -1)
 283                 cycle = -1;
 284         else if (cycle >= 8000)
 285                 cycle %= 8000;
 286
 287         isoctl_args[0] = cycle;
 288
 289         if (tag_mask < 0)
 290                 /* match all tags */
 291                 tag_mask = 0xF;
 292         isoctl_args[1] = tag_mask;
 293
 294         isoctl_args[2] = sync;
 295
 296         retval =
 297             iso->host->driver->isoctl(iso, RECV_START,
 298                                       (unsigned long)&isoctl_args[0]);
 299         if (retval)
 300                 return retval;
 301
 302         iso->flags |= HPSB_ISO_DRIVER_STARTED;
 303         return retval;
 304 }
 305
 306 /* check to make sure the user has not supplied bogus values of offset/len
 307    that would cause the kernel to access memory outside the buffer */
 308
 309 static int hpsb_iso_check_offset_len(struct hpsb_iso *iso,
 310                                      unsigned int offset, unsigned short len,
 311                                      unsigned int *out_offset,
 312                                      unsigned short *out_len)
 313 {
 314         if (offset >= iso->buf_size)
 315                 return -EFAULT;
 316
 317         /* make sure the packet does not go beyond the end of the buffer */
 318         if (offset + len > iso->buf_size)
 319                 return -EFAULT;
 320
 321         /* check for wrap-around */
 322         if (offset + len < offset)
 323                 return -EFAULT;
 324
 325         /* now we can trust 'offset' and 'length' */
 326         *out_offset = offset;
 327         *out_len = len;
 328
 329         return 0;
 330 }
 331
 332 int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
 333                                u8 tag, u8 sy)
 334 {
 335         struct hpsb_iso_packet_info *info;
 336         unsigned long flags;
 337         int rv;
 338
 339         if (iso->type != HPSB_ISO_XMIT)
 340                 return -EINVAL;
 341
 342         /* is there space in the buffer? */
 343         if (iso->n_ready_packets <= 0) {
 344                 return -EBUSY;
 345         }
 346
 347         info = &iso->infos[iso->first_packet];
 348
 349         /* check for bogus offset/length */
 350         if (hpsb_iso_check_offset_len
 351             (iso, offset, len, &info->offset, &info->len))
 352                 return -EFAULT;
 353
 354         info->tag = tag;
 355         info->sy = sy;
 356
 357         spin_lock_irqsave(&iso->lock, flags);
 358
 359         rv = iso->host->driver->isoctl(iso, XMIT_QUEUE, (unsigned long)info);
 360         if (rv)
 361                 goto out;
 362
 363         /* increment cursors */
 364         iso->first_packet = (iso->first_packet + 1) % iso->buf_packets;
 365         iso->xmit_cycle = (iso->xmit_cycle + 1) % 8000;
 366         iso->n_ready_packets--;
 367
 368         if (iso->prebuffer != 0) {
 369                 iso->prebuffer--;
 370                 if (iso->prebuffer <= 0) {
 371                         iso->prebuffer = 0;
 372                         rv = do_iso_xmit_start(iso, iso->start_cycle);
 373                 }
 374         }
 375
 376       out:
 377         spin_unlock_irqrestore(&iso->lock, flags);
 378         return rv;
 379 }
 380
 381 int hpsb_iso_xmit_sync(struct hpsb_iso *iso)
 382 {
 383         if (iso->type != HPSB_ISO_XMIT)
 384                 return -EINVAL;
 385
 386         return wait_event_interruptible(iso->waitq,
 387                                         hpsb_iso_n_ready(iso) ==
 388                                         iso->buf_packets);
 389 }
 390
 391 void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error)
 392 {
 393         unsigned long flags;
 394         spin_lock_irqsave(&iso->lock, flags);
 395
 396         /* predict the cycle of the next packet to be queued */
 397
 398         /* jump ahead by the number of packets that are already buffered */
 399         cycle += iso->buf_packets - iso->n_ready_packets;
 400         cycle %= 8000;
 401
 402         iso->xmit_cycle = cycle;
 403         iso->n_ready_packets++;
 404         iso->pkt_dma = (iso->pkt_dma + 1) % iso->buf_packets;
 405
 406         if (iso->n_ready_packets == iso->buf_packets || error != 0) {
 407                 /* the buffer has run empty! */
 408                 atomic_inc(&iso->overflows);
 409         }
 410
 411         spin_unlock_irqrestore(&iso->lock, flags);
 412 }
 413
 414 void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
 415                               u16 total_len, u16 cycle, u8 channel, u8 tag,
 416                               u8 sy)
 417 {
 418         unsigned long flags;
 419         spin_lock_irqsave(&iso->lock, flags);
 420
 421         if (iso->n_ready_packets == iso->buf_packets) {
 422                 /* overflow! */
 423                 atomic_inc(&iso->overflows);
 424                 /* Record size of this discarded packet */
 425                 iso->bytes_discarded += total_len;
 426         } else {
 427                 struct hpsb_iso_packet_info *info = &iso->infos[iso->pkt_dma];
 428                 info->offset = offset;
 429                 info->len = len;
 430                 info->total_len = total_len;
 431                 info->cycle = cycle;
 432                 info->channel = channel;
 433                 info->tag = tag;
 434                 info->sy = sy;
 435
 436                 iso->pkt_dma = (iso->pkt_dma + 1) % iso->buf_packets;
 437                 iso->n_ready_packets++;
 438         }
 439
 440         spin_unlock_irqrestore(&iso->lock, flags);
 441 }
 442
 443 int hpsb_iso_recv_release_packets(struct hpsb_iso *iso, unsigned int n_packets)
 444 {
 445         unsigned long flags;
 446         unsigned int i;
 447         int rv = 0;
 448
 449         if (iso->type != HPSB_ISO_RECV)
 450                 return -1;
 451
 452         spin_lock_irqsave(&iso->lock, flags);
 453         for (i = 0; i < n_packets; i++) {
 454                 rv = iso->host->driver->isoctl(iso, RECV_RELEASE,
 455                                                (unsigned long)&iso->infos[iso->
 456                                                                           first_packet]);
 457                 if (rv)
 458                         break;
 459
 460                 iso->first_packet = (iso->first_packet + 1) % iso->buf_packets;
 461                 iso->n_ready_packets--;
 462
 463                 /* release memory from packets discarded when queue was full  */
 464                 if (iso->n_ready_packets == 0) {        /* Release only after all prior packets handled */
 465                         if (iso->bytes_discarded != 0) {
 466                                 struct hpsb_iso_packet_info inf;
 467                                 inf.total_len = iso->bytes_discarded;
 468                                 iso->host->driver->isoctl(iso, RECV_RELEASE,
 469                                                           (unsigned long)&inf);
 470                                 iso->bytes_discarded = 0;
 471                         }
 472                 }
 473         }
 474         spin_unlock_irqrestore(&iso->lock, flags);
 475         return rv;
 476 }
 477
 478 void hpsb_iso_wake(struct hpsb_iso *iso)
 479 {
 480         wake_up_interruptible(&iso->waitq);
 481
 482         if (iso->callback)
 483                 iso->callback(iso);
 484 }