SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/media/video/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@radix.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  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  22  *  02111-1307  USA
  23  */
  24
  25 #include "cx18-driver.h"
  26 #include "cx18-queue.h"
  27 #include "cx18-streams.h"
  28 #include "cx18-scb.h"
  29 #include "cx18-io.h"
  30
  31 void cx18_buf_swap(struct cx18_buffer *buf)
  32 {
  33         int i;
  34
  35         for (i = 0; i < buf->bytesused; i += 4)
  36                 swab32s((u32 *)(buf->buf + i));
  37 }
  38
  39 void _cx18_mdl_swap(struct cx18_mdl *mdl)
  40 {
  41         struct cx18_buffer *buf;
  42
  43         list_for_each_entry(buf, &mdl->buf_list, list) {
  44                 if (buf->bytesused == 0)
  45                         break;
  46                 cx18_buf_swap(buf);
  47         }
  48 }
  49
  50 void cx18_queue_init(struct cx18_queue *q)
  51 {
  52         INIT_LIST_HEAD(&q->list);
  53         atomic_set(&q->depth, 0);
  54         q->bytesused = 0;
  55 }
  56
  57 struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
  58                                  struct cx18_queue *q, int to_front)
  59 {
  60         /* clear the mdl if it is not to be enqueued to the full queue */
  61         if (q != &s->q_full) {
  62                 mdl->bytesused = 0;
  63                 mdl->readpos = 0;
  64                 mdl->m_flags = 0;
  65                 mdl->skipped = 0;
  66                 mdl->curr_buf = NULL;
  67         }
  68
  69         /* q_busy is restricted to a max buffer count imposed by firmware */
  70         if (q == &s->q_busy &&
  71             atomic_read(&q->depth) >= CX18_MAX_FW_MDLS_PER_STREAM)
  72                 q = &s->q_free;
  73
  74         spin_lock(&q->lock);
  75
  76         if (to_front)
  77                 list_add(&mdl->list, &q->list); /* LIFO */
  78         else
  79                 list_add_tail(&mdl->list, &q->list); /* FIFO */
  80         q->bytesused += mdl->bytesused - mdl->readpos;
  81         atomic_inc(&q->depth);
  82
  83         spin_unlock(&q->lock);
  84         return q;
  85 }
  86
  87 struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
  88 {
  89         struct cx18_mdl *mdl = NULL;
  90
  91         spin_lock(&q->lock);
  92         if (!list_empty(&q->list)) {
  93                 mdl = list_first_entry(&q->list, struct cx18_mdl, list);
  94                 list_del_init(&mdl->list);
  95                 q->bytesused -= mdl->bytesused - mdl->readpos;
  96                 mdl->skipped = 0;
  97                 atomic_dec(&q->depth);
  98         }
  99         spin_unlock(&q->lock);
 100         return mdl;
 101 }
 102
 103 static void _cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
 104                                           struct cx18_mdl *mdl)
 105 {
 106         struct cx18_buffer *buf;
 107         u32 buf_size = s->buf_size;
 108         u32 bytesused = mdl->bytesused;
 109
 110         list_for_each_entry(buf, &mdl->buf_list, list) {
 111                 buf->readpos = 0;
 112                 if (bytesused >= buf_size) {
 113                         buf->bytesused = buf_size;
 114                         bytesused -= buf_size;
 115                 } else {
 116                         buf->bytesused = bytesused;
 117                         bytesused = 0;
 118                 }
 119                 cx18_buf_sync_for_cpu(s, buf);
 120         }
 121 }
 122
 123 static inline void cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
 124                                                 struct cx18_mdl *mdl)
 125 {
 126         struct cx18_buffer *buf;
 127
 128         if (list_is_singular(&mdl->buf_list)) {
 129                 buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
 130                                        list);
 131                 buf->bytesused = mdl->bytesused;
 132                 buf->readpos = 0;
 133                 cx18_buf_sync_for_cpu(s, buf);
 134         } else {
 135                 _cx18_mdl_update_bufs_for_cpu(s, mdl);
 136         }
 137 }
 138
 139 struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
 140         u32 bytesused)
 141 {
 142         struct cx18 *cx = s->cx;
 143         struct cx18_mdl *mdl;
 144         struct cx18_mdl *tmp;
 145         struct cx18_mdl *ret = NULL;
 146         LIST_HEAD(sweep_up);
 147
 148         /*
 149          * We don't have to acquire multiple q locks here, because we are
 150          * serialized by the single threaded work handler.
 151          * MDLs from the firmware will thus remain in order as
 152          * they are moved from q_busy to q_full or to the dvb ring buffer.
 153          */
 154         spin_lock(&s->q_busy.lock);
 155         list_for_each_entry_safe(mdl, tmp, &s->q_busy.list, list) {
 156                 /*
 157                  * We should find what the firmware told us is done,
 158                  * right at the front of the queue.  If we don't, we likely have
 159                  * missed an mdl done message from the firmware.
 160                  * Once we skip an mdl repeatedly, relative to the size of
 161                  * q_busy, we have high confidence we've missed it.
 162                  */
 163                 if (mdl->id != id) {
 164                         mdl->skipped++;
 165                         if (mdl->skipped >= atomic_read(&s->q_busy.depth)-1) {
 166                                 /* mdl must have fallen out of rotation */
 167                                 CX18_WARN("Skipped %s, MDL %d, %d "
 168                                           "times - it must have dropped out of "
 169                                           "rotation\n", s->name, mdl->id,
 170                                           mdl->skipped);
 171                                 /* Sweep it up to put it back into rotation */
 172                                 list_move_tail(&mdl->list, &sweep_up);
 173                                 atomic_dec(&s->q_busy.depth);
 174                         }
 175                         continue;
 176                 }
 177                 /*
 178                  * We pull the desired mdl off of the queue here.  Something
 179                  * will have to put it back on a queue later.
 180                  */
 181                 list_del_init(&mdl->list);
 182                 atomic_dec(&s->q_busy.depth);
 183                 ret = mdl;
 184                 break;
 185         }
 186         spin_unlock(&s->q_busy.lock);
 187
 188         /*
 189          * We found the mdl for which we were looking.  Get it ready for
 190          * the caller to put on q_full or in the dvb ring buffer.
 191          */
 192         if (ret != NULL) {
 193                 ret->bytesused = bytesused;
 194                 ret->skipped = 0;
 195                 /* 0'ed readpos, m_flags & curr_buf when mdl went on q_busy */
 196                 cx18_mdl_update_bufs_for_cpu(s, ret);
 197                 if (s->type != CX18_ENC_STREAM_TYPE_TS)
 198                         set_bit(CX18_F_M_NEED_SWAP, &ret->m_flags);
 199         }
 200
 201         /* Put any mdls the firmware is ignoring back into normal rotation */
 202         list_for_each_entry_safe(mdl, tmp, &sweep_up, list) {
 203                 list_del_init(&mdl->list);
 204                 cx18_enqueue(s, mdl, &s->q_free);
 205         }
 206         return ret;
 207 }
 208
 209 /* Move all mdls of a queue, while flushing the mdl */
 210 static void cx18_queue_flush(struct cx18_stream *s,
 211                              struct cx18_queue *q_src, struct cx18_queue *q_dst)
 212 {
 213         struct cx18_mdl *mdl;
 214
 215         /* It only makes sense to flush to q_free or q_idle */
 216         if (q_src == q_dst || q_dst == &s->q_full || q_dst == &s->q_busy)
 217                 return;
 218
 219         spin_lock(&q_src->lock);
 220         spin_lock(&q_dst->lock);
 221         while (!list_empty(&q_src->list)) {
 222                 mdl = list_first_entry(&q_src->list, struct cx18_mdl, list);
 223                 list_move_tail(&mdl->list, &q_dst->list);
 224                 mdl->bytesused = 0;
 225                 mdl->readpos = 0;
 226                 mdl->m_flags = 0;
 227                 mdl->skipped = 0;
 228                 mdl->curr_buf = NULL;
 229                 atomic_inc(&q_dst->depth);
 230         }
 231         cx18_queue_init(q_src);
 232         spin_unlock(&q_src->lock);
 233         spin_unlock(&q_dst->lock);
 234 }
 235
 236 void cx18_flush_queues(struct cx18_stream *s)
 237 {
 238         cx18_queue_flush(s, &s->q_busy, &s->q_free);
 239         cx18_queue_flush(s, &s->q_full, &s->q_free);
 240 }
 241
 242 /*
 243  * Note, s->buf_pool is not protected by a lock,
 244  * the stream better not have *anything* going on when calling this
 245  */
 246 void cx18_unload_queues(struct cx18_stream *s)
 247 {
 248         struct cx18_queue *q_idle = &s->q_idle;
 249         struct cx18_mdl *mdl;
 250         struct cx18_buffer *buf;
 251
 252         /* Move all MDLS to q_idle */
 253         cx18_queue_flush(s, &s->q_busy, q_idle);
 254         cx18_queue_flush(s, &s->q_full, q_idle);
 255         cx18_queue_flush(s, &s->q_free, q_idle);
 256
 257         /* Reset MDL id's and move all buffers back to the stream's buf_pool */
 258         spin_lock(&q_idle->lock);
 259         list_for_each_entry(mdl, &q_idle->list, list) {
 260                 while (!list_empty(&mdl->buf_list)) {
 261                         buf = list_first_entry(&mdl->buf_list,
 262                                                struct cx18_buffer, list);
 263                         list_move_tail(&buf->list, &s->buf_pool);
 264                         buf->bytesused = 0;
 265                         buf->readpos = 0;
 266                 }
 267                 mdl->id = s->mdl_base_idx; /* reset id to a "safe" value */
 268                 /* all other mdl fields were cleared by cx18_queue_flush() */
 269         }
 270         spin_unlock(&q_idle->lock);
 271 }
 272
 273 /*
 274  * Note, s->buf_pool is not protected by a lock,
 275  * the stream better not have *anything* going on when calling this
 276  */
 277 void cx18_load_queues(struct cx18_stream *s)
 278 {
 279         struct cx18 *cx = s->cx;
 280         struct cx18_mdl *mdl;
 281         struct cx18_buffer *buf;
 282         int mdl_id;
 283         int i;
 284         u32 partial_buf_size;
 285
 286         /*
 287          * Attach buffers to MDLs, give the MDLs ids, and add MDLs to q_free
 288          * Excess MDLs are left on q_idle
 289          * Excess buffers are left in buf_pool and/or on an MDL in q_idle
 290          */
 291         mdl_id = s->mdl_base_idx;
 292         for (mdl = cx18_dequeue(s, &s->q_idle), i = s->bufs_per_mdl;
 293              mdl != NULL && i == s->bufs_per_mdl;
 294              mdl = cx18_dequeue(s, &s->q_idle)) {
 295
 296                 mdl->id = mdl_id;
 297
 298                 for (i = 0; i < s->bufs_per_mdl; i++) {
 299                         if (list_empty(&s->buf_pool))
 300                                 break;
 301
 302                         buf = list_first_entry(&s->buf_pool, struct cx18_buffer,
 303                                                list);
 304                         list_move_tail(&buf->list, &mdl->buf_list);
 305
 306                         /* update the firmware's MDL array with this buffer */
 307                         cx18_writel(cx, buf->dma_handle,
 308                                     &cx->scb->cpu_mdl[mdl_id + i].paddr);
 309                         cx18_writel(cx, s->buf_size,
 310                                     &cx->scb->cpu_mdl[mdl_id + i].length);
 311                 }
 312
 313                 if (i == s->bufs_per_mdl) {
 314                         /*
 315                          * The encoder doesn't honor s->mdl_size.  So in the
 316                          * case of a non-integral number of buffers to meet
 317                          * mdl_size, we lie about the size of the last buffer
 318                          * in the MDL to get the encoder to really only send
 319                          * us mdl_size bytes per MDL transfer.
 320                          */
 321                         partial_buf_size = s->mdl_size % s->buf_size;
 322                         if (partial_buf_size) {
 323                                 cx18_writel(cx, partial_buf_size,
 324                                       &cx->scb->cpu_mdl[mdl_id + i - 1].length);
 325                         }
 326                         cx18_enqueue(s, mdl, &s->q_free);
 327                 } else {
 328                         /* Not enough buffers for this MDL; we won't use it */
 329                         cx18_push(s, mdl, &s->q_idle);
 330                 }
 331                 mdl_id += i;
 332         }
 333 }
 334
 335 void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl)
 336 {
 337         int dma = s->dma;
 338         u32 buf_size = s->buf_size;
 339         struct pci_dev *pci_dev = s->cx->pci_dev;
 340         struct cx18_buffer *buf;
 341
 342         list_for_each_entry(buf, &mdl->buf_list, list)
 343                 pci_dma_sync_single_for_device(pci_dev, buf->dma_handle,
 344                                                buf_size, dma);
 345 }
 346
 347 int cx18_stream_alloc(struct cx18_stream *s)
 348 {
 349         struct cx18 *cx = s->cx;
 350         int i;
 351
 352         if (s->buffers == 0)
 353                 return 0;
 354
 355         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers "
 356                         "(%d.%02d kB total)\n",
 357                 s->name, s->buffers, s->buf_size,
 358                 s->buffers * s->buf_size / 1024,
 359                 (s->buffers * s->buf_size * 100 / 1024) % 100);
 360
 361         if (((char __iomem *)&cx->scb->cpu_mdl[cx->free_mdl_idx + s->buffers] -
 362                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 363                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 364                                         ((char __iomem *)cx->scb->cpu_mdl));
 365
 366                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 367                 CX18_ERR("Max buffers = %zd\n",
 368                         bufsz / sizeof(struct cx18_mdl_ent));
 369                 return -ENOMEM;
 370         }
 371
 372         s->mdl_base_idx = cx->free_mdl_idx;
 373
 374         /* allocate stream buffers and MDLs */
 375         for (i = 0; i < s->buffers; i++) {
 376                 struct cx18_mdl *mdl;
 377                 struct cx18_buffer *buf;
 378
 379                 /* 1 MDL per buffer to handle the worst & also default case */
 380                 mdl = kzalloc(sizeof(struct cx18_mdl), GFP_KERNEL|__GFP_NOWARN);
 381                 if (mdl == NULL)
 382                         break;
 383
 384                 buf = kzalloc(sizeof(struct cx18_buffer),
 385                                 GFP_KERNEL|__GFP_NOWARN);
 386                 if (buf == NULL) {
 387                         kfree(mdl);
 388                         break;
 389                 }
 390
 391                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 392                 if (buf->buf == NULL) {
 393                         kfree(mdl);
 394                         kfree(buf);
 395                         break;
 396                 }
 397
 398                 INIT_LIST_HEAD(&mdl->list);
 399                 INIT_LIST_HEAD(&mdl->buf_list);
 400                 mdl->id = s->mdl_base_idx; /* a somewhat safe value */
 401                 cx18_enqueue(s, mdl, &s->q_idle);
 402
 403                 INIT_LIST_HEAD(&buf->list);
 404                 buf->dma_handle = pci_map_single(s->cx->pci_dev,
 405                                 buf->buf, s->buf_size, s->dma);
 406                 cx18_buf_sync_for_cpu(s, buf);
 407                 list_add_tail(&buf->list, &s->buf_pool);
 408         }
 409         if (i == s->buffers) {
 410                 cx->free_mdl_idx += s->buffers;
 411                 return 0;
 412         }
 413         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 414         cx18_stream_free(s);
 415         return -ENOMEM;
 416 }
 417
 418 void cx18_stream_free(struct cx18_stream *s)
 419 {
 420         struct cx18_mdl *mdl;
 421         struct cx18_buffer *buf;
 422         struct cx18 *cx = s->cx;
 423
 424         CX18_DEBUG_INFO("Deallocating buffers for %s stream\n", s->name);
 425
 426         /* move all buffers to buf_pool and all MDLs to q_idle */
 427         cx18_unload_queues(s);
 428
 429         /* empty q_idle */
 430         while ((mdl = cx18_dequeue(s, &s->q_idle)))
 431                 kfree(mdl);
 432
 433         /* empty buf_pool */
 434         while (!list_empty(&s->buf_pool)) {
 435                 buf = list_first_entry(&s->buf_pool, struct cx18_buffer, list);
 436                 list_del_init(&buf->list);
 437
 438                 pci_unmap_single(s->cx->pci_dev, buf->dma_handle,
 439                                 s->buf_size, s->dma);
 440                 kfree(buf->buf);
 441                 kfree(buf);
 442         }
 443 }