drivers/media/pci/cx18/cx18-queue.c

   1 /*
   2  *  cx18 buffer queues
   3  *
   4  *  Derived from ivtv-queue.c
   5  *
   6  *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
   7  *  Copyright (C) 2008  Andy Walls <awalls@md.metrocast.net>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  */
  19
  20 #include "cx18-driver.h"
  21 #include "cx18-queue.h"
  22 #include "cx18-streams.h"
  23 #include "cx18-scb.h"
  24 #include "cx18-io.h"
  25
  26 void cx18_buf_swap(struct cx18_buffer *buf)
  27 {
  28         int i;
  29
  30         for (i = 0; i < buf->bytesused; i += 4)
  31                 swab32s((u32 *)(buf->buf + i));
  32 }
  33
  34 void _cx18_mdl_swap(struct cx18_mdl *mdl)
  35 {
  36         struct cx18_buffer *buf;
  37
  38         list_for_each_entry(buf, &mdl->buf_list, list) {
  39                 if (buf->bytesused == 0)
  40                         break;
  41                 cx18_buf_swap(buf);
  42         }
  43 }
  44
  45 void cx18_queue_init(struct cx18_queue *q)
  46 {
  47         INIT_LIST_HEAD(&q->list);
  48         atomic_set(&q->depth, 0);
  49         q->bytesused = 0;
  50 }
  51
  52 struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
  53                                  struct cx18_queue *q, int to_front)
  54 {
  55         /* clear the mdl if it is not to be enqueued to the full queue */
  56         if (q != &s->q_full) {
  57                 mdl->bytesused = 0;
  58                 mdl->readpos = 0;
  59                 mdl->m_flags = 0;
  60                 mdl->skipped = 0;
  61                 mdl->curr_buf = NULL;
  62         }
  63
  64         /* q_busy is restricted to a max buffer count imposed by firmware */
  65         if (q == &s->q_busy &&
  66             atomic_read(&q->depth) >= CX18_MAX_FW_MDLS_PER_STREAM)
  67                 q = &s->q_free;
  68
  69         spin_lock(&q->lock);
  70
  71         if (to_front)
  72                 list_add(&mdl->list, &q->list); /* LIFO */
  73         else
  74                 list_add_tail(&mdl->list, &q->list); /* FIFO */
  75         q->bytesused += mdl->bytesused - mdl->readpos;
  76         atomic_inc(&q->depth);
  77
  78         spin_unlock(&q->lock);
  79         return q;
  80 }
  81
  82 struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
  83 {
  84         struct cx18_mdl *mdl = NULL;
  85
  86         spin_lock(&q->lock);
  87         if (!list_empty(&q->list)) {
  88                 mdl = list_first_entry(&q->list, struct cx18_mdl, list);
  89                 list_del_init(&mdl->list);
  90                 q->bytesused -= mdl->bytesused - mdl->readpos;
  91                 mdl->skipped = 0;
  92                 atomic_dec(&q->depth);
  93         }
  94         spin_unlock(&q->lock);
  95         return mdl;
  96 }
  97
  98 static void _cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
  99                                           struct cx18_mdl *mdl)
 100 {
 101         struct cx18_buffer *buf;
 102         u32 buf_size = s->buf_size;
 103         u32 bytesused = mdl->bytesused;
 104
 105         list_for_each_entry(buf, &mdl->buf_list, list) {
 106                 buf->readpos = 0;
 107                 if (bytesused >= buf_size) {
 108                         buf->bytesused = buf_size;
 109                         bytesused -= buf_size;
 110                 } else {
 111                         buf->bytesused = bytesused;
 112                         bytesused = 0;
 113                 }
 114                 cx18_buf_sync_for_cpu(s, buf);
 115         }
 116 }
 117
 118 static inline void cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
 119                                                 struct cx18_mdl *mdl)
 120 {
 121         struct cx18_buffer *buf;
 122
 123         if (list_is_singular(&mdl->buf_list)) {
 124                 buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
 125                                        list);
 126                 buf->bytesused = mdl->bytesused;
 127                 buf->readpos = 0;
 128                 cx18_buf_sync_for_cpu(s, buf);
 129         } else {
 130                 _cx18_mdl_update_bufs_for_cpu(s, mdl);
 131         }
 132 }
 133
 134 struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
 135         u32 bytesused)
 136 {
 137         struct cx18 *cx = s->cx;
 138         struct cx18_mdl *mdl;
 139         struct cx18_mdl *tmp;
 140         struct cx18_mdl *ret = NULL;
 141         LIST_HEAD(sweep_up);
 142
 143         /*
 144          * We don't have to acquire multiple q locks here, because we are
 145          * serialized by the single threaded work handler.
 146          * MDLs from the firmware will thus remain in order as
 147          * they are moved from q_busy to q_full or to the dvb ring buffer.
 148          */
 149         spin_lock(&s->q_busy.lock);
 150         list_for_each_entry_safe(mdl, tmp, &s->q_busy.list, list) {
 151                 /*
 152                  * We should find what the firmware told us is done,
 153                  * right at the front of the queue.  If we don't, we likely have
 154                  * missed an mdl done message from the firmware.
 155                  * Once we skip an mdl repeatedly, relative to the size of
 156                  * q_busy, we have high confidence we've missed it.
 157                  */
 158                 if (mdl->id != id) {
 159                         mdl->skipped++;
 160                         if (mdl->skipped >= atomic_read(&s->q_busy.depth)-1) {
 161                                 /* mdl must have fallen out of rotation */
 162                                 CX18_WARN("Skipped %s, MDL %d, %d times - it must have dropped out of rotation\n",
 163                                           s->name, mdl->id,
 164                                           mdl->skipped);
 165                                 /* Sweep it up to put it back into rotation */
 166                                 list_move_tail(&mdl->list, &sweep_up);
 167                                 atomic_dec(&s->q_busy.depth);
 168                         }
 169                         continue;
 170                 }
 171                 /*
 172                  * We pull the desired mdl off of the queue here.  Something
 173                  * will have to put it back on a queue later.
 174                  */
 175                 list_del_init(&mdl->list);
 176                 atomic_dec(&s->q_busy.depth);
 177                 ret = mdl;
 178                 break;
 179         }
 180         spin_unlock(&s->q_busy.lock);
 181
 182         /*
 183          * We found the mdl for which we were looking.  Get it ready for
 184          * the caller to put on q_full or in the dvb ring buffer.
 185          */
 186         if (ret != NULL) {
 187                 ret->bytesused = bytesused;
 188                 ret->skipped = 0;
 189                 /* 0'ed readpos, m_flags & curr_buf when mdl went on q_busy */
 190                 cx18_mdl_update_bufs_for_cpu(s, ret);
 191                 if (s->type != CX18_ENC_STREAM_TYPE_TS)
 192                         set_bit(CX18_F_M_NEED_SWAP, &ret->m_flags);
 193         }
 194
 195         /* Put any mdls the firmware is ignoring back into normal rotation */
 196         list_for_each_entry_safe(mdl, tmp, &sweep_up, list) {
 197                 list_del_init(&mdl->list);
 198                 cx18_enqueue(s, mdl, &s->q_free);
 199         }
 200         return ret;
 201 }
 202
 203 /* Move all mdls of a queue, while flushing the mdl */
 204 static void cx18_queue_flush(struct cx18_stream *s,
 205                              struct cx18_queue *q_src, struct cx18_queue *q_dst)
 206 {
 207         struct cx18_mdl *mdl;
 208
 209         /* It only makes sense to flush to q_free or q_idle */
 210         if (q_src == q_dst || q_dst == &s->q_full || q_dst == &s->q_busy)
 211                 return;
 212
 213         spin_lock(&q_src->lock);
 214         spin_lock(&q_dst->lock);
 215         while (!list_empty(&q_src->list)) {
 216                 mdl = list_first_entry(&q_src->list, struct cx18_mdl, list);
 217                 list_move_tail(&mdl->list, &q_dst->list);
 218                 mdl->bytesused = 0;
 219                 mdl->readpos = 0;
 220                 mdl->m_flags = 0;
 221                 mdl->skipped = 0;
 222                 mdl->curr_buf = NULL;
 223                 atomic_inc(&q_dst->depth);
 224         }
 225         cx18_queue_init(q_src);
 226         spin_unlock(&q_src->lock);
 227         spin_unlock(&q_dst->lock);
 228 }
 229
 230 void cx18_flush_queues(struct cx18_stream *s)
 231 {
 232         cx18_queue_flush(s, &s->q_busy, &s->q_free);
 233         cx18_queue_flush(s, &s->q_full, &s->q_free);
 234 }
 235
 236 /*
 237  * Note, s->buf_pool is not protected by a lock,
 238  * the stream better not have *anything* going on when calling this
 239  */
 240 void cx18_unload_queues(struct cx18_stream *s)
 241 {
 242         struct cx18_queue *q_idle = &s->q_idle;
 243         struct cx18_mdl *mdl;
 244         struct cx18_buffer *buf;
 245
 246         /* Move all MDLS to q_idle */
 247         cx18_queue_flush(s, &s->q_busy, q_idle);
 248         cx18_queue_flush(s, &s->q_full, q_idle);
 249         cx18_queue_flush(s, &s->q_free, q_idle);
 250
 251         /* Reset MDL id's and move all buffers back to the stream's buf_pool */
 252         spin_lock(&q_idle->lock);
 253         list_for_each_entry(mdl, &q_idle->list, list) {
 254                 while (!list_empty(&mdl->buf_list)) {
 255                         buf = list_first_entry(&mdl->buf_list,
 256                                                struct cx18_buffer, list);
 257                         list_move_tail(&buf->list, &s->buf_pool);
 258                         buf->bytesused = 0;
 259                         buf->readpos = 0;
 260                 }
 261                 mdl->id = s->mdl_base_idx; /* reset id to a "safe" value */
 262                 /* all other mdl fields were cleared by cx18_queue_flush() */
 263         }
 264         spin_unlock(&q_idle->lock);
 265 }
 266
 267 /*
 268  * Note, s->buf_pool is not protected by a lock,
 269  * the stream better not have *anything* going on when calling this
 270  */
 271 void cx18_load_queues(struct cx18_stream *s)
 272 {
 273         struct cx18 *cx = s->cx;
 274         struct cx18_mdl *mdl;
 275         struct cx18_buffer *buf;
 276         int mdl_id;
 277         int i;
 278         u32 partial_buf_size;
 279
 280         /*
 281          * Attach buffers to MDLs, give the MDLs ids, and add MDLs to q_free
 282          * Excess MDLs are left on q_idle
 283          * Excess buffers are left in buf_pool and/or on an MDL in q_idle
 284          */
 285         mdl_id = s->mdl_base_idx;
 286         for (mdl = cx18_dequeue(s, &s->q_idle), i = s->bufs_per_mdl;
 287              mdl != NULL && i == s->bufs_per_mdl;
 288              mdl = cx18_dequeue(s, &s->q_idle)) {
 289
 290                 mdl->id = mdl_id;
 291
 292                 for (i = 0; i < s->bufs_per_mdl; i++) {
 293                         if (list_empty(&s->buf_pool))
 294                                 break;
 295
 296                         buf = list_first_entry(&s->buf_pool, struct cx18_buffer,
 297                                                list);
 298                         list_move_tail(&buf->list, &mdl->buf_list);
 299
 300                         /* update the firmware's MDL array with this buffer */
 301                         cx18_writel(cx, buf->dma_handle,
 302                                     &cx->scb->cpu_mdl[mdl_id + i].paddr);
 303                         cx18_writel(cx, s->buf_size,
 304                                     &cx->scb->cpu_mdl[mdl_id + i].length);
 305                 }
 306
 307                 if (i == s->bufs_per_mdl) {
 308                         /*
 309                          * The encoder doesn't honor s->mdl_size.  So in the
 310                          * case of a non-integral number of buffers to meet
 311                          * mdl_size, we lie about the size of the last buffer
 312                          * in the MDL to get the encoder to really only send
 313                          * us mdl_size bytes per MDL transfer.
 314                          */
 315                         partial_buf_size = s->mdl_size % s->buf_size;
 316                         if (partial_buf_size) {
 317                                 cx18_writel(cx, partial_buf_size,
 318                                       &cx->scb->cpu_mdl[mdl_id + i - 1].length);
 319                         }
 320                         cx18_enqueue(s, mdl, &s->q_free);
 321                 } else {
 322                         /* Not enough buffers for this MDL; we won't use it */
 323                         cx18_push(s, mdl, &s->q_idle);
 324                 }
 325                 mdl_id += i;
 326         }
 327 }
 328
 329 void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl)
 330 {
 331         int dma = s->dma;
 332         u32 buf_size = s->buf_size;
 333         struct pci_dev *pci_dev = s->cx->pci_dev;
 334         struct cx18_buffer *buf;
 335
 336         list_for_each_entry(buf, &mdl->buf_list, list)
 337                 pci_dma_sync_single_for_device(pci_dev, buf->dma_handle,
 338                                                buf_size, dma);
 339 }
 340
 341 int cx18_stream_alloc(struct cx18_stream *s)
 342 {
 343         struct cx18 *cx = s->cx;
 344         int i;
 345
 346         if (s->buffers == 0)
 347                 return 0;
 348
 349         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%d.%02d kB total)\n",
 350                 s->name, s->buffers, s->buf_size,
 351                 s->buffers * s->buf_size / 1024,
 352                 (s->buffers * s->buf_size * 100 / 1024) % 100);
 353
 354         if (((char __iomem *)&cx->scb->cpu_mdl[cx->free_mdl_idx + s->buffers] -
 355                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 356                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 357                                         ((char __iomem *)cx->scb->cpu_mdl));
 358
 359                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 360                 CX18_ERR("Max buffers = %zu\n",
 361                         bufsz / sizeof(struct cx18_mdl_ent));
 362                 return -ENOMEM;
 363         }
 364
 365         s->mdl_base_idx = cx->free_mdl_idx;
 366
 367         /* allocate stream buffers and MDLs */
 368         for (i = 0; i < s->buffers; i++) {
 369                 struct cx18_mdl *mdl;
 370                 struct cx18_buffer *buf;
 371
 372                 /* 1 MDL per buffer to handle the worst & also default case */
 373                 mdl = kzalloc(sizeof(struct cx18_mdl), GFP_KERNEL|__GFP_NOWARN);
 374                 if (mdl == NULL)
 375                         break;
 376
 377                 buf = kzalloc(sizeof(struct cx18_buffer),
 378                                 GFP_KERNEL|__GFP_NOWARN);
 379                 if (buf == NULL) {
 380                         kfree(mdl);
 381                         break;
 382                 }
 383
 384                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 385                 if (buf->buf == NULL) {
 386                         kfree(mdl);
 387                         kfree(buf);
 388                         break;
 389                 }
 390
 391                 INIT_LIST_HEAD(&mdl->list);
 392                 INIT_LIST_HEAD(&mdl->buf_list);
 393                 mdl->id = s->mdl_base_idx; /* a somewhat safe value */
 394                 cx18_enqueue(s, mdl, &s->q_idle);
 395
 396                 INIT_LIST_HEAD(&buf->list);
 397                 buf->dma_handle = pci_map_single(s->cx->pci_dev,
 398                                 buf->buf, s->buf_size, s->dma);
 399                 cx18_buf_sync_for_cpu(s, buf);
 400                 list_add_tail(&buf->list, &s->buf_pool);
 401         }
 402         if (i == s->buffers) {
 403                 cx->free_mdl_idx += s->buffers;
 404                 return 0;
 405         }
 406         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 407         cx18_stream_free(s);
 408         return -ENOMEM;
 409 }
 410
 411 void cx18_stream_free(struct cx18_stream *s)
 412 {
 413         struct cx18_mdl *mdl;
 414         struct cx18_buffer *buf;
 415         struct cx18 *cx = s->cx;
 416
 417         CX18_DEBUG_INFO("Deallocating buffers for %s stream\n", s->name);
 418
 419         /* move all buffers to buf_pool and all MDLs to q_idle */
 420         cx18_unload_queues(s);
 421
 422         /* empty q_idle */
 423         while ((mdl = cx18_dequeue(s, &s->q_idle)))
 424                 kfree(mdl);
 425
 426         /* empty buf_pool */
 427         while (!list_empty(&s->buf_pool)) {
 428                 buf = list_first_entry(&s->buf_pool, struct cx18_buffer, list);
 429                 list_del_init(&buf->list);
 430
 431                 pci_unmap_single(s->cx->pci_dev, buf->dma_handle,
 432                                 s->buf_size, s->dma);
 433                 kfree(buf->buf);
 434                 kfree(buf);
 435         }
 436 }