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_set_buf_bytesused(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         }
 120 }
 121
 122 static inline void cx18_mdl_set_buf_bytesused(struct cx18_stream *s,
 123                                               struct cx18_mdl *mdl)
 124 {
 125         struct cx18_buffer *buf;
 126
 127         if (list_is_singular(&mdl->buf_list)) {
 128                 buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
 129                                        list);
 130                 buf->bytesused = mdl->bytesused;
 131                 buf->readpos = 0;
 132         } else {
 133                 _cx18_mdl_set_buf_bytesused(s, mdl);
 134         }
 135 }
 136
 137 struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
 138         u32 bytesused)
 139 {
 140         struct cx18 *cx = s->cx;
 141         struct cx18_mdl *mdl;
 142         struct cx18_mdl *tmp;
 143         struct cx18_mdl *ret = NULL;
 144         LIST_HEAD(sweep_up);
 145
 146         /*
 147          * We don't have to acquire multiple q locks here, because we are
 148          * serialized by the single threaded work handler.
 149          * MDLs from the firmware will thus remain in order as
 150          * they are moved from q_busy to q_full or to the dvb ring buffer.
 151          */
 152         spin_lock(&s->q_busy.lock);
 153         list_for_each_entry_safe(mdl, tmp, &s->q_busy.list, list) {
 154                 /*
 155                  * We should find what the firmware told us is done,
 156                  * right at the front of the queue.  If we don't, we likely have
 157                  * missed an mdl done message from the firmware.
 158                  * Once we skip an mdl repeatedly, relative to the size of
 159                  * q_busy, we have high confidence we've missed it.
 160                  */
 161                 if (mdl->id != id) {
 162                         mdl->skipped++;
 163                         if (mdl->skipped >= atomic_read(&s->q_busy.depth)-1) {
 164                                 /* mdl must have fallen out of rotation */
 165                                 CX18_WARN("Skipped %s, MDL %d, %d "
 166                                           "times - it must have dropped out of "
 167                                           "rotation\n", s->name, mdl->id,
 168                                           mdl->skipped);
 169                                 /* Sweep it up to put it back into rotation */
 170                                 list_move_tail(&mdl->list, &sweep_up);
 171                                 atomic_dec(&s->q_busy.depth);
 172                         }
 173                         continue;
 174                 }
 175                 /*
 176                  * We pull the desired mdl off of the queue here.  Something
 177                  * will have to put it back on a queue later.
 178                  */
 179                 list_del_init(&mdl->list);
 180                 atomic_dec(&s->q_busy.depth);
 181                 ret = mdl;
 182                 break;
 183         }
 184         spin_unlock(&s->q_busy.lock);
 185
 186         /*
 187          * We found the mdl for which we were looking.  Get it ready for
 188          * the caller to put on q_full or in the dvb ring buffer.
 189          */
 190         if (ret != NULL) {
 191                 ret->bytesused = bytesused;
 192                 ret->skipped = 0;
 193                 /* 0'ed readpos, m_flags & curr_buf when mdl went on q_busy */
 194                 cx18_mdl_set_buf_bytesused(s, ret);
 195                 cx18_mdl_sync_for_cpu(s, ret);
 196                 if (s->type != CX18_ENC_STREAM_TYPE_TS)
 197                         set_bit(CX18_F_M_NEED_SWAP, &ret->m_flags);
 198         }
 199
 200         /* Put any mdls the firmware is ignoring back into normal rotation */
 201         list_for_each_entry_safe(mdl, tmp, &sweep_up, list) {
 202                 list_del_init(&mdl->list);
 203                 cx18_enqueue(s, mdl, &s->q_free);
 204         }
 205         return ret;
 206 }
 207
 208 /* Move all mdls of a queue, while flushing the mdl */
 209 static void cx18_queue_flush(struct cx18_stream *s,
 210                              struct cx18_queue *q_src, struct cx18_queue *q_dst)
 211 {
 212         struct cx18_mdl *mdl;
 213
 214         /* It only makes sense to flush to q_free or q_idle */
 215         if (q_src == q_dst || q_dst == &s->q_full || q_dst == &s->q_busy)
 216                 return;
 217
 218         spin_lock(&q_src->lock);
 219         spin_lock(&q_dst->lock);
 220         while (!list_empty(&q_src->list)) {
 221                 mdl = list_first_entry(&q_src->list, struct cx18_mdl, list);
 222                 list_move_tail(&mdl->list, &q_dst->list);
 223                 mdl->bytesused = 0;
 224                 mdl->readpos = 0;
 225                 mdl->m_flags = 0;
 226                 mdl->skipped = 0;
 227                 mdl->curr_buf = NULL;
 228                 atomic_inc(&q_dst->depth);
 229         }
 230         cx18_queue_init(q_src);
 231         spin_unlock(&q_src->lock);
 232         spin_unlock(&q_dst->lock);
 233 }
 234
 235 void cx18_flush_queues(struct cx18_stream *s)
 236 {
 237         cx18_queue_flush(s, &s->q_busy, &s->q_free);
 238         cx18_queue_flush(s, &s->q_full, &s->q_free);
 239 }
 240
 241 /*
 242  * Note, s->buf_pool is not protected by a lock,
 243  * the stream better not have *anything* going on when calling this
 244  */
 245 void cx18_unload_queues(struct cx18_stream *s)
 246 {
 247         struct cx18_queue *q_idle = &s->q_idle;
 248         struct cx18_mdl *mdl;
 249         struct cx18_buffer *buf;
 250
 251         /* Move all MDLS to q_idle */
 252         cx18_queue_flush(s, &s->q_busy, q_idle);
 253         cx18_queue_flush(s, &s->q_full, q_idle);
 254         cx18_queue_flush(s, &s->q_free, q_idle);
 255
 256         /* Reset MDL id's and move all buffers back to the stream's buf_pool */
 257         spin_lock(&q_idle->lock);
 258         list_for_each_entry(mdl, &q_idle->list, list) {
 259                 while (!list_empty(&mdl->buf_list)) {
 260                         buf = list_first_entry(&mdl->buf_list,
 261                                                struct cx18_buffer, list);
 262                         list_move_tail(&buf->list, &s->buf_pool);
 263                         buf->bytesused = 0;
 264                         buf->readpos = 0;
 265                 }
 266                 mdl->id = s->mdl_base_idx; /* reset id to a "safe" value */
 267                 /* all other mdl fields were cleared by cx18_queue_flush() */
 268         }
 269         spin_unlock(&q_idle->lock);
 270 }
 271
 272 /*
 273  * Note, s->buf_pool is not protected by a lock,
 274  * the stream better not have *anything* going on when calling this
 275  */
 276 void cx18_load_queues(struct cx18_stream *s)
 277 {
 278         struct cx18 *cx = s->cx;
 279         struct cx18_mdl *mdl;
 280         struct cx18_buffer *buf;
 281         int mdl_id;
 282         int i;
 283
 284         /*
 285          * Attach buffers to MDLs, give the MDLs ids, and add MDLs to q_free
 286          * Excess MDLs are left on q_idle
 287          * Excess buffers are left in buf_pool and/or on an MDL in q_idle
 288          */
 289         mdl_id = s->mdl_base_idx;
 290         for (mdl = cx18_dequeue(s, &s->q_idle), i = s->bufs_per_mdl;
 291              mdl != NULL && i == s->bufs_per_mdl;
 292              mdl = cx18_dequeue(s, &s->q_idle)) {
 293
 294                 mdl->id = mdl_id;
 295
 296                 for (i = 0; i < s->bufs_per_mdl; i++) {
 297                         if (list_empty(&s->buf_pool))
 298                                 break;
 299
 300                         buf = list_first_entry(&s->buf_pool, struct cx18_buffer,
 301                                                list);
 302                         list_move_tail(&buf->list, &mdl->buf_list);
 303
 304                         /* update the firmware's MDL array with this buffer */
 305                         cx18_writel(cx, buf->dma_handle,
 306                                     &cx->scb->cpu_mdl[mdl_id + i].paddr);
 307                         cx18_writel(cx, s->buf_size,
 308                                     &cx->scb->cpu_mdl[mdl_id + i].length);
 309                 }
 310
 311                 if (i == s->bufs_per_mdl)
 312                         cx18_enqueue(s, mdl, &s->q_free);
 313                 else
 314                         cx18_push(s, mdl, &s->q_idle); /* not enough buffers */
 315                 mdl_id += i;
 316         }
 317 }
 318
 319 void _cx18_mdl_sync_for_cpu(struct cx18_stream *s, struct cx18_mdl *mdl)
 320 {
 321         int dma = s->dma;
 322         u32 buf_size = s->buf_size;
 323         struct pci_dev *pci_dev = s->cx->pci_dev;
 324         struct cx18_buffer *buf;
 325
 326         list_for_each_entry(buf, &mdl->buf_list, list)
 327                 pci_dma_sync_single_for_cpu(pci_dev, buf->dma_handle,
 328                                             buf_size, dma);
 329 }
 330
 331 void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl)
 332 {
 333         int dma = s->dma;
 334         u32 buf_size = s->buf_size;
 335         struct pci_dev *pci_dev = s->cx->pci_dev;
 336         struct cx18_buffer *buf;
 337
 338         list_for_each_entry(buf, &mdl->buf_list, list)
 339                 pci_dma_sync_single_for_device(pci_dev, buf->dma_handle,
 340                                                buf_size, dma);
 341 }
 342
 343 int cx18_stream_alloc(struct cx18_stream *s)
 344 {
 345         struct cx18 *cx = s->cx;
 346         int i;
 347
 348         if (s->buffers == 0)
 349                 return 0;
 350
 351         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers "
 352                         "(%d.%02d kB total)\n",
 353                 s->name, s->buffers, s->buf_size,
 354                 s->buffers * s->buf_size / 1024,
 355                 (s->buffers * s->buf_size * 100 / 1024) % 100);
 356
 357         if (((char __iomem *)&cx->scb->cpu_mdl[cx->free_mdl_idx + s->buffers] -
 358                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 359                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 360                                         ((char __iomem *)cx->scb->cpu_mdl));
 361
 362                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 363                 CX18_ERR("Max buffers = %zd\n",
 364                         bufsz / sizeof(struct cx18_mdl_ent));
 365                 return -ENOMEM;
 366         }
 367
 368         s->mdl_base_idx = cx->free_mdl_idx;
 369
 370         /* allocate stream buffers and MDLs */
 371         for (i = 0; i < s->buffers; i++) {
 372                 struct cx18_mdl *mdl;
 373                 struct cx18_buffer *buf;
 374
 375                 /* 1 MDL per buffer to handle the worst & also default case */
 376                 mdl = kzalloc(sizeof(struct cx18_mdl), GFP_KERNEL|__GFP_NOWARN);
 377                 if (mdl == NULL)
 378                         break;
 379
 380                 buf = kzalloc(sizeof(struct cx18_buffer),
 381                                 GFP_KERNEL|__GFP_NOWARN);
 382                 if (buf == NULL) {
 383                         kfree(mdl);
 384                         break;
 385                 }
 386
 387                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 388                 if (buf->buf == NULL) {
 389                         kfree(mdl);
 390                         kfree(buf);
 391                         break;
 392                 }
 393
 394                 INIT_LIST_HEAD(&mdl->list);
 395                 INIT_LIST_HEAD(&mdl->buf_list);
 396                 mdl->id = s->mdl_base_idx; /* a somewhat safe value */
 397                 cx18_enqueue(s, mdl, &s->q_idle);
 398
 399                 INIT_LIST_HEAD(&buf->list);
 400                 buf->dma_handle = pci_map_single(s->cx->pci_dev,
 401                                 buf->buf, s->buf_size, s->dma);
 402                 cx18_buf_sync_for_cpu(s, buf);
 403                 list_add_tail(&buf->list, &s->buf_pool);
 404         }
 405         if (i == s->buffers) {
 406                 cx->free_mdl_idx += s->buffers;
 407                 return 0;
 408         }
 409         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 410         cx18_stream_free(s);
 411         return -ENOMEM;
 412 }
 413
 414 void cx18_stream_free(struct cx18_stream *s)
 415 {
 416         struct cx18_mdl *mdl;
 417         struct cx18_buffer *buf;
 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 }