1 /* 2 * 3 * 4 * Copyright (C) 2005 Mike Isely <isely@pobox.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 * 19 */ 20 21 #include "pvrusb2-ioread.h" 22 #include "pvrusb2-debug.h" 23 #include <linux/errno.h> 24 #include <linux/string.h> 25 #include <linux/mm.h> 26 #include <linux/slab.h> 27 #include <linux/mutex.h> 28 #include <asm/uaccess.h> 29 30 #define BUFFER_COUNT 32 31 #define BUFFER_SIZE PAGE_ALIGN(0x4000) 32 33 struct pvr2_ioread { 34 struct pvr2_stream *stream; 35 char *buffer_storage[BUFFER_COUNT]; 36 char *sync_key_ptr; 37 unsigned int sync_key_len; 38 unsigned int sync_buf_offs; 39 unsigned int sync_state; 40 unsigned int sync_trashed_count; 41 int enabled; // Streaming is on 42 int spigot_open; // OK to pass data to client 43 int stream_running; // Passing data to client now 44 45 /* State relevant to current buffer being read */ 46 struct pvr2_buffer *c_buf; 47 char *c_data_ptr; 48 unsigned int c_data_len; 49 unsigned int c_data_offs; 50 struct mutex mutex; 51 }; 52 53 static int pvr2_ioread_init(struct pvr2_ioread *cp) 54 { 55 unsigned int idx; 56 57 cp->stream = NULL; 58 mutex_init(&cp->mutex); 59 60 for (idx = 0; idx < BUFFER_COUNT; idx++) { 61 cp->buffer_storage[idx] = kmalloc(BUFFER_SIZE,GFP_KERNEL); 62 if (!(cp->buffer_storage[idx])) break; 63 } 64 65 if (idx < BUFFER_COUNT) { 66 // An allocation appears to have failed 67 for (idx = 0; idx < BUFFER_COUNT; idx++) { 68 if (!(cp->buffer_storage[idx])) continue; 69 kfree(cp->buffer_storage[idx]); 70 } 71 return -ENOMEM; 72 } 73 return 0; 74 } 75 76 static void pvr2_ioread_done(struct pvr2_ioread *cp) 77 { 78 unsigned int idx; 79 80 pvr2_ioread_setup(cp,NULL); 81 for (idx = 0; idx < BUFFER_COUNT; idx++) { 82 if (!(cp->buffer_storage[idx])) continue; 83 kfree(cp->buffer_storage[idx]); 84 } 85 } 86 87 struct pvr2_ioread *pvr2_ioread_create(void) 88 { 89 struct pvr2_ioread *cp; 90 cp = kzalloc(sizeof(*cp),GFP_KERNEL); 91 if (!cp) return NULL; 92 pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_create id=%p",cp); 93 if (pvr2_ioread_init(cp) < 0) { 94 kfree(cp); 95 return NULL; 96 } 97 return cp; 98 } 99 100 void pvr2_ioread_destroy(struct pvr2_ioread *cp) 101 { 102 if (!cp) return; 103 pvr2_ioread_done(cp); 104 pvr2_trace(PVR2_TRACE_STRUCT,"pvr2_ioread_destroy id=%p",cp); 105 if (cp->sync_key_ptr) { 106 kfree(cp->sync_key_ptr); 107 cp->sync_key_ptr = NULL; 108 } 109 kfree(cp); 110 } 111 112 void pvr2_ioread_set_sync_key(struct pvr2_ioread *cp, 113 const char *sync_key_ptr, 114 unsigned int sync_key_len) 115 { 116 if (!cp) return; 117 118 if (!sync_key_ptr) sync_key_len = 0; 119 if ((sync_key_len == cp->sync_key_len) && 120 ((!sync_key_len) || 121 (!memcmp(sync_key_ptr,cp->sync_key_ptr,sync_key_len)))) return; 122 123 if (sync_key_len != cp->sync_key_len) { 124 if (cp->sync_key_ptr) { 125 kfree(cp->sync_key_ptr); 126 cp->sync_key_ptr = NULL; 127 } 128 cp->sync_key_len = 0; 129 if (sync_key_len) { 130 cp->sync_key_ptr = kmalloc(sync_key_len,GFP_KERNEL); 131 if (cp->sync_key_ptr) { 132 cp->sync_key_len = sync_key_len; 133 } 134 } 135 } 136 if (!cp->sync_key_len) return; 137 memcpy(cp->sync_key_ptr,sync_key_ptr,cp->sync_key_len); 138 } 139 140 static void pvr2_ioread_stop(struct pvr2_ioread *cp) 141 { 142 if (!(cp->enabled)) return; 143 pvr2_trace(PVR2_TRACE_START_STOP, 144 "/*---TRACE_READ---*/ pvr2_ioread_stop id=%p",cp); 145 pvr2_stream_kill(cp->stream); 146 cp->c_buf = NULL; 147 cp->c_data_ptr = NULL; 148 cp->c_data_len = 0; 149 cp->c_data_offs = 0; 150 cp->enabled = 0; 151 cp->stream_running = 0; 152 cp->spigot_open = 0; 153 if (cp->sync_state) { 154 pvr2_trace(PVR2_TRACE_DATA_FLOW, 155 "/*---TRACE_READ---*/ sync_state <== 0"); 156 cp->sync_state = 0; 157 } 158 } 159 160 static int pvr2_ioread_start(struct pvr2_ioread *cp) 161 { 162 int stat; 163 struct pvr2_buffer *bp; 164 if (cp->enabled) return 0; 165 if (!(cp->stream)) return 0; 166 pvr2_trace(PVR2_TRACE_START_STOP, 167 "/*---TRACE_READ---*/ pvr2_ioread_start id=%p",cp); 168 while ((bp = pvr2_stream_get_idle_buffer(cp->stream)) != NULL) { 169 stat = pvr2_buffer_queue(bp); 170 if (stat < 0) { 171 pvr2_trace(PVR2_TRACE_DATA_FLOW, 172 "/*---TRACE_READ---*/" 173 " pvr2_ioread_start id=%p" 174 " error=%d", 175 cp,stat); 176 pvr2_ioread_stop(cp); 177 return stat; 178 } 179 } 180 cp->enabled = !0; 181 cp->c_buf = NULL; 182 cp->c_data_ptr = NULL; 183 cp->c_data_len = 0; 184 cp->c_data_offs = 0; 185 cp->stream_running = 0; 186 if (cp->sync_key_len) { 187 pvr2_trace(PVR2_TRACE_DATA_FLOW, 188 "/*---TRACE_READ---*/ sync_state <== 1"); 189 cp->sync_state = 1; 190 cp->sync_trashed_count = 0; 191 cp->sync_buf_offs = 0; 192 } 193 cp->spigot_open = 0; 194 return 0; 195 } 196 197 struct pvr2_stream *pvr2_ioread_get_stream(struct pvr2_ioread *cp) 198 { 199 return cp->stream; 200 } 201 202 int pvr2_ioread_setup(struct pvr2_ioread *cp,struct pvr2_stream *sp) 203 { 204 int ret; 205 unsigned int idx; 206 struct pvr2_buffer *bp; 207 208 mutex_lock(&cp->mutex); 209 do { 210 if (cp->stream) { 211 pvr2_trace(PVR2_TRACE_START_STOP, 212 "/*---TRACE_READ---*/" 213 " pvr2_ioread_setup (tear-down) id=%p",cp); 214 pvr2_ioread_stop(cp); 215 pvr2_stream_kill(cp->stream); 216 if (pvr2_stream_get_buffer_count(cp->stream)) { 217 pvr2_stream_set_buffer_count(cp->stream,0); 218 } 219 cp->stream = NULL; 220 } 221 if (sp) { 222 pvr2_trace(PVR2_TRACE_START_STOP, 223 "/*---TRACE_READ---*/" 224 " pvr2_ioread_setup (setup) id=%p",cp); 225 pvr2_stream_kill(sp); 226 ret = pvr2_stream_set_buffer_count(sp,BUFFER_COUNT); 227 if (ret < 0) { 228 mutex_unlock(&cp->mutex); 229 return ret; 230 } 231 for (idx = 0; idx < BUFFER_COUNT; idx++) { 232 bp = pvr2_stream_get_buffer(sp,idx); 233 pvr2_buffer_set_buffer(bp, 234 cp->buffer_storage[idx], 235 BUFFER_SIZE); 236 } 237 cp->stream = sp; 238 } 239 } while (0); 240 mutex_unlock(&cp->mutex); 241 242 return 0; 243 } 244 245 int pvr2_ioread_set_enabled(struct pvr2_ioread *cp,int fl) 246 { 247 int ret = 0; 248 if ((!fl) == (!(cp->enabled))) return ret; 249 250 mutex_lock(&cp->mutex); 251 do { 252 if (fl) { 253 ret = pvr2_ioread_start(cp); 254 } else { 255 pvr2_ioread_stop(cp); 256 } 257 } while (0); 258 mutex_unlock(&cp->mutex); 259 return ret; 260 } 261 262 static int pvr2_ioread_get_buffer(struct pvr2_ioread *cp) 263 { 264 int stat; 265 266 while (cp->c_data_len <= cp->c_data_offs) { 267 if (cp->c_buf) { 268 // Flush out current buffer first. 269 stat = pvr2_buffer_queue(cp->c_buf); 270 if (stat < 0) { 271 // Streaming error... 272 pvr2_trace(PVR2_TRACE_DATA_FLOW, 273 "/*---TRACE_READ---*/" 274 " pvr2_ioread_read id=%p" 275 " queue_error=%d", 276 cp,stat); 277 pvr2_ioread_stop(cp); 278 return 0; 279 } 280 cp->c_buf = NULL; 281 cp->c_data_ptr = NULL; 282 cp->c_data_len = 0; 283 cp->c_data_offs = 0; 284 } 285 // Now get a freshly filled buffer. 286 cp->c_buf = pvr2_stream_get_ready_buffer(cp->stream); 287 if (!cp->c_buf) break; // Nothing ready; done. 288 cp->c_data_len = pvr2_buffer_get_count(cp->c_buf); 289 if (!cp->c_data_len) { 290 // Nothing transferred. Was there an error? 291 stat = pvr2_buffer_get_status(cp->c_buf); 292 if (stat < 0) { 293 // Streaming error... 294 pvr2_trace(PVR2_TRACE_DATA_FLOW, 295 "/*---TRACE_READ---*/" 296 " pvr2_ioread_read id=%p" 297 " buffer_error=%d", 298 cp,stat); 299 pvr2_ioread_stop(cp); 300 // Give up. 301 return 0; 302 } 303 // Start over... 304 continue; 305 } 306 cp->c_data_offs = 0; 307 cp->c_data_ptr = cp->buffer_storage[ 308 pvr2_buffer_get_id(cp->c_buf)]; 309 } 310 return !0; 311 } 312 313 static void pvr2_ioread_filter(struct pvr2_ioread *cp) 314 { 315 unsigned int idx; 316 if (!cp->enabled) return; 317 if (cp->sync_state != 1) return; 318 319 // Search the stream for our synchronization key. This is made 320 // complicated by the fact that in order to be honest with 321 // ourselves here we must search across buffer boundaries... 322 mutex_lock(&cp->mutex); 323 while (1) { 324 // Ensure we have a buffer 325 if (!pvr2_ioread_get_buffer(cp)) break; 326 if (!cp->c_data_len) break; 327 328 // Now walk the buffer contents until we match the key or 329 // run out of buffer data. 330 for (idx = cp->c_data_offs; idx < cp->c_data_len; idx++) { 331 if (cp->sync_buf_offs >= cp->sync_key_len) break; 332 if (cp->c_data_ptr[idx] == 333 cp->sync_key_ptr[cp->sync_buf_offs]) { 334 // Found the next key byte 335 (cp->sync_buf_offs)++; 336 } else { 337 // Whoops, mismatched. Start key over... 338 cp->sync_buf_offs = 0; 339 } 340 } 341 342 // Consume what we've walked through 343 cp->c_data_offs += idx; 344 cp->sync_trashed_count += idx; 345 346 // If we've found the key, then update state and get out. 347 if (cp->sync_buf_offs >= cp->sync_key_len) { 348 cp->sync_trashed_count -= cp->sync_key_len; 349 pvr2_trace(PVR2_TRACE_DATA_FLOW, 350 "/*---TRACE_READ---*/" 351 " sync_state <== 2 (skipped %u bytes)", 352 cp->sync_trashed_count); 353 cp->sync_state = 2; 354 cp->sync_buf_offs = 0; 355 break; 356 } 357 358 if (cp->c_data_offs < cp->c_data_len) { 359 // Sanity check - should NEVER get here 360 pvr2_trace(PVR2_TRACE_ERROR_LEGS, 361 "ERROR: pvr2_ioread filter sync problem" 362 " len=%u offs=%u", 363 cp->c_data_len,cp->c_data_offs); 364 // Get out so we don't get stuck in an infinite 365 // loop. 366 break; 367 } 368 369 continue; // (for clarity) 370 } 371 mutex_unlock(&cp->mutex); 372 } 373 374 int pvr2_ioread_avail(struct pvr2_ioread *cp) 375 { 376 int ret; 377 if (!(cp->enabled)) { 378 // Stream is not enabled; so this is an I/O error 379 return -EIO; 380 } 381 382 if (cp->sync_state == 1) { 383 pvr2_ioread_filter(cp); 384 if (cp->sync_state == 1) return -EAGAIN; 385 } 386 387 ret = 0; 388 if (cp->stream_running) { 389 if (!pvr2_stream_get_ready_count(cp->stream)) { 390 // No data available at all right now. 391 ret = -EAGAIN; 392 } 393 } else { 394 if (pvr2_stream_get_ready_count(cp->stream) < BUFFER_COUNT/2) { 395 // Haven't buffered up enough yet; try again later 396 ret = -EAGAIN; 397 } 398 } 399 400 if ((!(cp->spigot_open)) != (!(ret == 0))) { 401 cp->spigot_open = (ret == 0); 402 pvr2_trace(PVR2_TRACE_DATA_FLOW, 403 "/*---TRACE_READ---*/ data is %s", 404 cp->spigot_open ? "available" : "pending"); 405 } 406 407 return ret; 408 } 409 410 int pvr2_ioread_read(struct pvr2_ioread *cp,void __user *buf,unsigned int cnt) 411 { 412 unsigned int copied_cnt; 413 unsigned int bcnt; 414 const char *src; 415 int stat; 416 int ret = 0; 417 unsigned int req_cnt = cnt; 418 419 if (!cnt) { 420 pvr2_trace(PVR2_TRACE_TRAP, 421 "/*---TRACE_READ---*/ pvr2_ioread_read id=%p" 422 " ZERO Request? Returning zero.",cp); 423 return 0; 424 } 425 426 stat = pvr2_ioread_avail(cp); 427 if (stat < 0) return stat; 428 429 cp->stream_running = !0; 430 431 mutex_lock(&cp->mutex); 432 do { 433 434 // Suck data out of the buffers and copy to the user 435 copied_cnt = 0; 436 if (!buf) cnt = 0; 437 while (1) { 438 if (!pvr2_ioread_get_buffer(cp)) { 439 ret = -EIO; 440 break; 441 } 442 443 if (!cnt) break; 444 445 if (cp->sync_state == 2) { 446 // We're repeating the sync key data into 447 // the stream. 448 src = cp->sync_key_ptr + cp->sync_buf_offs; 449 bcnt = cp->sync_key_len - cp->sync_buf_offs; 450 } else { 451 // Normal buffer copy 452 src = cp->c_data_ptr + cp->c_data_offs; 453 bcnt = cp->c_data_len - cp->c_data_offs; 454 } 455 456 if (!bcnt) break; 457 458 // Don't run past user's buffer 459 if (bcnt > cnt) bcnt = cnt; 460 461 if (copy_to_user(buf,src,bcnt)) { 462 // User supplied a bad pointer? 463 // Give up - this *will* cause data 464 // to be lost. 465 ret = -EFAULT; 466 break; 467 } 468 cnt -= bcnt; 469 buf += bcnt; 470 copied_cnt += bcnt; 471 472 if (cp->sync_state == 2) { 473 // Update offset inside sync key that we're 474 // repeating back out. 475 cp->sync_buf_offs += bcnt; 476 if (cp->sync_buf_offs >= cp->sync_key_len) { 477 // Consumed entire key; switch mode 478 // to normal. 479 pvr2_trace(PVR2_TRACE_DATA_FLOW, 480 "/*---TRACE_READ---*/" 481 " sync_state <== 0"); 482 cp->sync_state = 0; 483 } 484 } else { 485 // Update buffer offset. 486 cp->c_data_offs += bcnt; 487 } 488 } 489 490 } while (0); 491 mutex_unlock(&cp->mutex); 492 493 if (!ret) { 494 if (copied_cnt) { 495 // If anything was copied, return that count 496 ret = copied_cnt; 497 } else { 498 // Nothing copied; suggest to caller that another 499 // attempt should be tried again later 500 ret = -EAGAIN; 501 } 502 } 503 504 pvr2_trace(PVR2_TRACE_DATA_FLOW, 505 "/*---TRACE_READ---*/ pvr2_ioread_read" 506 " id=%p request=%d result=%d", 507 cp,req_cnt,ret); 508 return ret; 509 } 510