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 } 437