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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  cx18 buffer queues
   4  *
   5  *  Derived from ivtv-queue.c
   6  *
   7  *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
   8  *  Copyright (C) 2008  Andy Walls <awalls@md.metrocast.net>
   9  */
  10
  11 #include "cx18-driver.h"
  12 #include "cx18-queue.h"
  13 #include "cx18-streams.h"
  14 #include "cx18-scb.h"
  15 #include "cx18-io.h"
  16
  17 void cx18_buf_swap(struct cx18_buffer *buf)
  18 {
  19         int i;
  20
  21         for (i = 0; i < buf->bytesused; i += 4)
  22                 swab32s((u32 *)(buf->buf + i));
  23 }
  24
  25 void _cx18_mdl_swap(struct cx18_mdl *mdl)
  26 {
  27         struct cx18_buffer *buf;
  28
  29         list_for_each_entry(buf, &mdl->buf_list, list) {
  30                 if (buf->bytesused == 0)
  31                         break;
  32                 cx18_buf_swap(buf);
  33         }
  34 }
  35
  36 void cx18_queue_init(struct cx18_queue *q)
  37 {
  38         INIT_LIST_HEAD(&q->list);
  39         atomic_set(&q->depth, 0);
  40         q->bytesused = 0;
  41 }
  42
  43 struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
  44                                  struct cx18_queue *q, int to_front)
  45 {
  46         /* clear the mdl if it is not to be enqueued to the full queue */
  47         if (q != &s->q_full) {
  48                 mdl->bytesused = 0;
  49                 mdl->readpos = 0;
  50                 mdl->m_flags = 0;
  51                 mdl->skipped = 0;
  52                 mdl->curr_buf = NULL;
  53         }
  54
  55         /* q_busy is restricted to a max buffer count imposed by firmware */
  56         if (q == &s->q_busy &&
  57             atomic_read(&q->depth) >= CX18_MAX_FW_MDLS_PER_STREAM)
  58                 q = &s->q_free;
  59
  60         spin_lock(&q->lock);
  61
  62         if (to_front)
  63                 list_add(&mdl->list, &q->list); /* LIFO */
  64         else
  65                 list_add_tail(&mdl->list, &q->list); /* FIFO */
  66         q->bytesused += mdl->bytesused - mdl->readpos;
  67         atomic_inc(&q->depth);
  68
  69         spin_unlock(&q->lock);
  70         return q;
  71 }
  72
  73 struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q)
  74 {
  75         struct cx18_mdl *mdl = NULL;
  76
  77         spin_lock(&q->lock);
  78         if (!list_empty(&q->list)) {
  79                 mdl = list_first_entry(&q->list, struct cx18_mdl, list);
  80                 list_del_init(&mdl->list);
  81                 q->bytesused -= mdl->bytesused - mdl->readpos;
  82                 mdl->skipped = 0;
  83                 atomic_dec(&q->depth);
  84         }
  85         spin_unlock(&q->lock);
  86         return mdl;
  87 }
  88
  89 static void _cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
  90                                           struct cx18_mdl *mdl)
  91 {
  92         struct cx18_buffer *buf;
  93         u32 buf_size = s->buf_size;
  94         u32 bytesused = mdl->bytesused;
  95
  96         list_for_each_entry(buf, &mdl->buf_list, list) {
  97                 buf->readpos = 0;
  98                 if (bytesused >= buf_size) {
  99                         buf->bytesused = buf_size;
 100                         bytesused -= buf_size;
 101                 } else {
 102                         buf->bytesused = bytesused;
 103                         bytesused = 0;
 104                 }
 105                 cx18_buf_sync_for_cpu(s, buf);
 106         }
 107 }
 108
 109 static inline void cx18_mdl_update_bufs_for_cpu(struct cx18_stream *s,
 110                                                 struct cx18_mdl *mdl)
 111 {
 112         struct cx18_buffer *buf;
 113
 114         if (list_is_singular(&mdl->buf_list)) {
 115                 buf = list_first_entry(&mdl->buf_list, struct cx18_buffer,
 116                                        list);
 117                 buf->bytesused = mdl->bytesused;
 118                 buf->readpos = 0;
 119                 cx18_buf_sync_for_cpu(s, buf);
 120         } else {
 121                 _cx18_mdl_update_bufs_for_cpu(s, mdl);
 122         }
 123 }
 124
 125 struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
 126         u32 bytesused)
 127 {
 128         struct cx18 *cx = s->cx;
 129         struct cx18_mdl *mdl;
 130         struct cx18_mdl *tmp;
 131         struct cx18_mdl *ret = NULL;
 132         LIST_HEAD(sweep_up);
 133
 134         /*
 135          * We don't have to acquire multiple q locks here, because we are
 136          * serialized by the single threaded work handler.
 137          * MDLs from the firmware will thus remain in order as
 138          * they are moved from q_busy to q_full or to the dvb ring buffer.
 139          */
 140         spin_lock(&s->q_busy.lock);
 141         list_for_each_entry_safe(mdl, tmp, &s->q_busy.list, list) {
 142                 /*
 143                  * We should find what the firmware told us is done,
 144                  * right at the front of the queue.  If we don't, we likely have
 145                  * missed an mdl done message from the firmware.
 146                  * Once we skip an mdl repeatedly, relative to the size of
 147                  * q_busy, we have high confidence we've missed it.
 148                  */
 149                 if (mdl->id != id) {
 150                         mdl->skipped++;
 151                         if (mdl->skipped >= atomic_read(&s->q_busy.depth)-1) {
 152                                 /* mdl must have fallen out of rotation */
 153                                 CX18_WARN("Skipped %s, MDL %d, %d times - it must have dropped out of rotation\n",
 154                                           s->name, mdl->id,
 155                                           mdl->skipped);
 156                                 /* Sweep it up to put it back into rotation */
 157                                 list_move_tail(&mdl->list, &sweep_up);
 158                                 atomic_dec(&s->q_busy.depth);
 159                         }
 160                         continue;
 161                 }
 162                 /*
 163                  * We pull the desired mdl off of the queue here.  Something
 164                  * will have to put it back on a queue later.
 165                  */
 166                 list_del_init(&mdl->list);
 167                 atomic_dec(&s->q_busy.depth);
 168                 ret = mdl;
 169                 break;
 170         }
 171         spin_unlock(&s->q_busy.lock);
 172
 173         /*
 174          * We found the mdl for which we were looking.  Get it ready for
 175          * the caller to put on q_full or in the dvb ring buffer.
 176          */
 177         if (ret != NULL) {
 178                 ret->bytesused = bytesused;
 179                 ret->skipped = 0;
 180                 /* 0'ed readpos, m_flags & curr_buf when mdl went on q_busy */
 181                 cx18_mdl_update_bufs_for_cpu(s, ret);
 182                 if (s->type != CX18_ENC_STREAM_TYPE_TS)
 183                         set_bit(CX18_F_M_NEED_SWAP, &ret->m_flags);
 184         }
 185
 186         /* Put any mdls the firmware is ignoring back into normal rotation */
 187         list_for_each_entry_safe(mdl, tmp, &sweep_up, list) {
 188                 list_del_init(&mdl->list);
 189                 cx18_enqueue(s, mdl, &s->q_free);
 190         }
 191         return ret;
 192 }
 193
 194 /* Move all mdls of a queue, while flushing the mdl */
 195 static void cx18_queue_flush(struct cx18_stream *s,
 196                              struct cx18_queue *q_src, struct cx18_queue *q_dst)
 197 {
 198         struct cx18_mdl *mdl;
 199
 200         /* It only makes sense to flush to q_free or q_idle */
 201         if (q_src == q_dst || q_dst == &s->q_full || q_dst == &s->q_busy)
 202                 return;
 203
 204         spin_lock(&q_src->lock);
 205         spin_lock(&q_dst->lock);
 206         while (!list_empty(&q_src->list)) {
 207                 mdl = list_first_entry(&q_src->list, struct cx18_mdl, list);
 208                 list_move_tail(&mdl->list, &q_dst->list);
 209                 mdl->bytesused = 0;
 210                 mdl->readpos = 0;
 211                 mdl->m_flags = 0;
 212                 mdl->skipped = 0;
 213                 mdl->curr_buf = NULL;
 214                 atomic_inc(&q_dst->depth);
 215         }
 216         cx18_queue_init(q_src);
 217         spin_unlock(&q_src->lock);
 218         spin_unlock(&q_dst->lock);
 219 }
 220
 221 void cx18_flush_queues(struct cx18_stream *s)
 222 {
 223         cx18_queue_flush(s, &s->q_busy, &s->q_free);
 224         cx18_queue_flush(s, &s->q_full, &s->q_free);
 225 }
 226
 227 /*
 228  * Note, s->buf_pool is not protected by a lock,
 229  * the stream better not have *anything* going on when calling this
 230  */
 231 void cx18_unload_queues(struct cx18_stream *s)
 232 {
 233         struct cx18_queue *q_idle = &s->q_idle;
 234         struct cx18_mdl *mdl;
 235         struct cx18_buffer *buf;
 236
 237         /* Move all MDLS to q_idle */
 238         cx18_queue_flush(s, &s->q_busy, q_idle);
 239         cx18_queue_flush(s, &s->q_full, q_idle);
 240         cx18_queue_flush(s, &s->q_free, q_idle);
 241
 242         /* Reset MDL id's and move all buffers back to the stream's buf_pool */
 243         spin_lock(&q_idle->lock);
 244         list_for_each_entry(mdl, &q_idle->list, list) {
 245                 while (!list_empty(&mdl->buf_list)) {
 246                         buf = list_first_entry(&mdl->buf_list,
 247                                                struct cx18_buffer, list);
 248                         list_move_tail(&buf->list, &s->buf_pool);
 249                         buf->bytesused = 0;
 250                         buf->readpos = 0;
 251                 }
 252                 mdl->id = s->mdl_base_idx; /* reset id to a "safe" value */
 253                 /* all other mdl fields were cleared by cx18_queue_flush() */
 254         }
 255         spin_unlock(&q_idle->lock);
 256 }
 257
 258 /*
 259  * Note, s->buf_pool is not protected by a lock,
 260  * the stream better not have *anything* going on when calling this
 261  */
 262 void cx18_load_queues(struct cx18_stream *s)
 263 {
 264         struct cx18 *cx = s->cx;
 265         struct cx18_mdl *mdl;
 266         struct cx18_buffer *buf;
 267         int mdl_id;
 268         int i;
 269         u32 partial_buf_size;
 270
 271         /*
 272          * Attach buffers to MDLs, give the MDLs ids, and add MDLs to q_free
 273          * Excess MDLs are left on q_idle
 274          * Excess buffers are left in buf_pool and/or on an MDL in q_idle
 275          */
 276         mdl_id = s->mdl_base_idx;
 277         for (mdl = cx18_dequeue(s, &s->q_idle), i = s->bufs_per_mdl;
 278              mdl != NULL && i == s->bufs_per_mdl;
 279              mdl = cx18_dequeue(s, &s->q_idle)) {
 280
 281                 mdl->id = mdl_id;
 282
 283                 for (i = 0; i < s->bufs_per_mdl; i++) {
 284                         if (list_empty(&s->buf_pool))
 285                                 break;
 286
 287                         buf = list_first_entry(&s->buf_pool, struct cx18_buffer,
 288                                                list);
 289                         list_move_tail(&buf->list, &mdl->buf_list);
 290
 291                         /* update the firmware's MDL array with this buffer */
 292                         cx18_writel(cx, buf->dma_handle,
 293                                     &cx->scb->cpu_mdl[mdl_id + i].paddr);
 294                         cx18_writel(cx, s->buf_size,
 295                                     &cx->scb->cpu_mdl[mdl_id + i].length);
 296                 }
 297
 298                 if (i == s->bufs_per_mdl) {
 299                         /*
 300                          * The encoder doesn't honor s->mdl_size.  So in the
 301                          * case of a non-integral number of buffers to meet
 302                          * mdl_size, we lie about the size of the last buffer
 303                          * in the MDL to get the encoder to really only send
 304                          * us mdl_size bytes per MDL transfer.
 305                          */
 306                         partial_buf_size = s->mdl_size % s->buf_size;
 307                         if (partial_buf_size) {
 308                                 cx18_writel(cx, partial_buf_size,
 309                                       &cx->scb->cpu_mdl[mdl_id + i - 1].length);
 310                         }
 311                         cx18_enqueue(s, mdl, &s->q_free);
 312                 } else {
 313                         /* Not enough buffers for this MDL; we won't use it */
 314                         cx18_push(s, mdl, &s->q_idle);
 315                 }
 316                 mdl_id += i;
 317         }
 318 }
 319
 320 void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl)
 321 {
 322         int dma = s->dma;
 323         u32 buf_size = s->buf_size;
 324         struct pci_dev *pci_dev = s->cx->pci_dev;
 325         struct cx18_buffer *buf;
 326
 327         list_for_each_entry(buf, &mdl->buf_list, list)
 328                 pci_dma_sync_single_for_device(pci_dev, buf->dma_handle,
 329                                                buf_size, dma);
 330 }
 331
 332 int cx18_stream_alloc(struct cx18_stream *s)
 333 {
 334         struct cx18 *cx = s->cx;
 335         int i;
 336
 337         if (s->buffers == 0)
 338                 return 0;
 339
 340         CX18_DEBUG_INFO("Allocate %s stream: %d x %d buffers (%d.%02d kB total)\n",
 341                 s->name, s->buffers, s->buf_size,
 342                 s->buffers * s->buf_size / 1024,
 343                 (s->buffers * s->buf_size * 100 / 1024) % 100);
 344
 345         if (((char __iomem *)&cx->scb->cpu_mdl[cx->free_mdl_idx + s->buffers] -
 346                                 (char __iomem *)cx->scb) > SCB_RESERVED_SIZE) {
 347                 unsigned bufsz = (((char __iomem *)cx->scb) + SCB_RESERVED_SIZE -
 348                                         ((char __iomem *)cx->scb->cpu_mdl));
 349
 350                 CX18_ERR("Too many buffers, cannot fit in SCB area\n");
 351                 CX18_ERR("Max buffers = %zu\n",
 352                         bufsz / sizeof(struct cx18_mdl_ent));
 353                 return -ENOMEM;
 354         }
 355
 356         s->mdl_base_idx = cx->free_mdl_idx;
 357
 358         /* allocate stream buffers and MDLs */
 359         for (i = 0; i < s->buffers; i++) {
 360                 struct cx18_mdl *mdl;
 361                 struct cx18_buffer *buf;
 362
 363                 /* 1 MDL per buffer to handle the worst & also default case */
 364                 mdl = kzalloc(sizeof(struct cx18_mdl), GFP_KERNEL|__GFP_NOWARN);
 365                 if (mdl == NULL)
 366                         break;
 367
 368                 buf = kzalloc(sizeof(struct cx18_buffer),
 369                                 GFP_KERNEL|__GFP_NOWARN);
 370                 if (buf == NULL) {
 371                         kfree(mdl);
 372                         break;
 373                 }
 374
 375                 buf->buf = kmalloc(s->buf_size, GFP_KERNEL|__GFP_NOWARN);
 376                 if (buf->buf == NULL) {
 377                         kfree(mdl);
 378                         kfree(buf);
 379                         break;
 380                 }
 381
 382                 INIT_LIST_HEAD(&mdl->list);
 383                 INIT_LIST_HEAD(&mdl->buf_list);
 384                 mdl->id = s->mdl_base_idx; /* a somewhat safe value */
 385                 cx18_enqueue(s, mdl, &s->q_idle);
 386
 387                 INIT_LIST_HEAD(&buf->list);
 388                 buf->dma_handle = pci_map_single(s->cx->pci_dev,
 389                                 buf->buf, s->buf_size, s->dma);
 390                 cx18_buf_sync_for_cpu(s, buf);
 391                 list_add_tail(&buf->list, &s->buf_pool);
 392         }
 393         if (i == s->buffers) {
 394                 cx->free_mdl_idx += s->buffers;
 395                 return 0;
 396         }
 397         CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name);
 398         cx18_stream_free(s);
 399         return -ENOMEM;
 400 }
 401
 402 void cx18_stream_free(struct cx18_stream *s)
 403 {
 404         struct cx18_mdl *mdl;
 405         struct cx18_buffer *buf;
 406         struct cx18 *cx = s->cx;
 407
 408         CX18_DEBUG_INFO("Deallocating buffers for %s stream\n", s->name);
 409
 410         /* move all buffers to buf_pool and all MDLs to q_idle */
 411         cx18_unload_queues(s);
 412
 413         /* empty q_idle */
 414         while ((mdl = cx18_dequeue(s, &s->q_idle)))
 415                 kfree(mdl);
 416
 417         /* empty buf_pool */
 418         while (!list_empty(&s->buf_pool)) {
 419                 buf = list_first_entry(&s->buf_pool, struct cx18_buffer, list);
 420                 list_del_init(&buf->list);
 421
 422                 pci_unmap_single(s->cx->pci_dev, buf->dma_handle,
 423                                 s->buf_size, s->dma);
 424                 kfree(buf->buf);
 425                 kfree(buf);
 426         }
 427 }