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 dma_sync_single_for_device(&pci_dev->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 = dma_map_single(&s->cx->pci_dev->dev, 389 buf->buf, s->buf_size, 390 s->dma); 391 cx18_buf_sync_for_cpu(s, buf); 392 list_add_tail(&buf->list, &s->buf_pool); 393 } 394 if (i == s->buffers) { 395 cx->free_mdl_idx += s->buffers; 396 return 0; 397 } 398 CX18_ERR("Couldn't allocate buffers for %s stream\n", s->name); 399 cx18_stream_free(s); 400 return -ENOMEM; 401 } 402 403 void cx18_stream_free(struct cx18_stream *s) 404 { 405 struct cx18_mdl *mdl; 406 struct cx18_buffer *buf; 407 struct cx18 *cx = s->cx; 408 409 CX18_DEBUG_INFO("Deallocating buffers for %s stream\n", s->name); 410 411 /* move all buffers to buf_pool and all MDLs to q_idle */ 412 cx18_unload_queues(s); 413 414 /* empty q_idle */ 415 while ((mdl = cx18_dequeue(s, &s->q_idle))) 416 kfree(mdl); 417 418 /* empty buf_pool */ 419 while (!list_empty(&s->buf_pool)) { 420 buf = list_first_entry(&s->buf_pool, struct cx18_buffer, list); 421 list_del_init(&buf->list); 422 423 dma_unmap_single(&s->cx->pci_dev->dev, buf->dma_handle, 424 s->buf_size, s->dma); 425 kfree(buf->buf); 426 kfree(buf); 427 } 428 } 429