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 <linux/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---*/ pvr2_ioread_start id=%p error=%d", 173 cp,stat); 174 pvr2_ioread_stop(cp); 175 return stat; 176 } 177 } 178 cp->enabled = !0; 179 cp->c_buf = NULL; 180 cp->c_data_ptr = NULL; 181 cp->c_data_len = 0; 182 cp->c_data_offs = 0; 183 cp->stream_running = 0; 184 if (cp->sync_key_len) { 185 pvr2_trace(PVR2_TRACE_DATA_FLOW, 186 "/*---TRACE_READ---*/ sync_state <== 1"); 187 cp->sync_state = 1; 188 cp->sync_trashed_count = 0; 189 cp->sync_buf_offs = 0; 190 } 191 cp->spigot_open = 0; 192 return 0; 193 } 194 195 struct pvr2_stream *pvr2_ioread_get_stream(struct pvr2_ioread *cp) 196 { 197 return cp->stream; 198 } 199 200 int pvr2_ioread_setup(struct pvr2_ioread *cp,struct pvr2_stream *sp) 201 { 202 int ret; 203 unsigned int idx; 204 struct pvr2_buffer *bp; 205 206 mutex_lock(&cp->mutex); 207 do { 208 if (cp->stream) { 209 pvr2_trace(PVR2_TRACE_START_STOP, 210 "/*---TRACE_READ---*/ pvr2_ioread_setup (tear-down) id=%p", 211 cp); 212 pvr2_ioread_stop(cp); 213 pvr2_stream_kill(cp->stream); 214 if (pvr2_stream_get_buffer_count(cp->stream)) { 215 pvr2_stream_set_buffer_count(cp->stream,0); 216 } 217 cp->stream = NULL; 218 } 219 if (sp) { 220 pvr2_trace(PVR2_TRACE_START_STOP, 221 "/*---TRACE_READ---*/ pvr2_ioread_setup (setup) id=%p", 222 cp); 223 pvr2_stream_kill(sp); 224 ret = pvr2_stream_set_buffer_count(sp,BUFFER_COUNT); 225 if (ret < 0) { 226 mutex_unlock(&cp->mutex); 227 return ret; 228 } 229 for (idx = 0; idx < BUFFER_COUNT; idx++) { 230 bp = pvr2_stream_get_buffer(sp,idx); 231 pvr2_buffer_set_buffer(bp, 232 cp->buffer_storage[idx], 233 BUFFER_SIZE); 234 } 235 cp->stream = sp; 236 } 237 } while (0); 238 mutex_unlock(&cp->mutex); 239 240 return 0; 241 } 242 243 int pvr2_ioread_set_enabled(struct pvr2_ioread *cp,int fl) 244 { 245 int ret = 0; 246 if ((!fl) == (!(cp->enabled))) return ret; 247 248 mutex_lock(&cp->mutex); 249 do { 250 if (fl) { 251 ret = pvr2_ioread_start(cp); 252 } else { 253 pvr2_ioread_stop(cp); 254 } 255 } while (0); 256 mutex_unlock(&cp->mutex); 257 return ret; 258 } 259 260 static int pvr2_ioread_get_buffer(struct pvr2_ioread *cp) 261 { 262 int stat; 263 264 while (cp->c_data_len <= cp->c_data_offs) { 265 if (cp->c_buf) { 266 // Flush out current buffer first. 267 stat = pvr2_buffer_queue(cp->c_buf); 268 if (stat < 0) { 269 // Streaming error... 270 pvr2_trace(PVR2_TRACE_DATA_FLOW, 271 "/*---TRACE_READ---*/ pvr2_ioread_read id=%p queue_error=%d", 272 cp,stat); 273 pvr2_ioread_stop(cp); 274 return 0; 275 } 276 cp->c_buf = NULL; 277 cp->c_data_ptr = NULL; 278 cp->c_data_len = 0; 279 cp->c_data_offs = 0; 280 } 281 // Now get a freshly filled buffer. 282 cp->c_buf = pvr2_stream_get_ready_buffer(cp->stream); 283 if (!cp->c_buf) break; // Nothing ready; done. 284 cp->c_data_len = pvr2_buffer_get_count(cp->c_buf); 285 if (!cp->c_data_len) { 286 // Nothing transferred. Was there an error? 287 stat = pvr2_buffer_get_status(cp->c_buf); 288 if (stat < 0) { 289 // Streaming error... 290 pvr2_trace(PVR2_TRACE_DATA_FLOW, 291 "/*---TRACE_READ---*/ pvr2_ioread_read id=%p buffer_error=%d", 292 cp,stat); 293 pvr2_ioread_stop(cp); 294 // Give up. 295 return 0; 296 } 297 // Start over... 298 continue; 299 } 300 cp->c_data_offs = 0; 301 cp->c_data_ptr = cp->buffer_storage[ 302 pvr2_buffer_get_id(cp->c_buf)]; 303 } 304 return !0; 305 } 306 307 static void pvr2_ioread_filter(struct pvr2_ioread *cp) 308 { 309 unsigned int idx; 310 if (!cp->enabled) return; 311 if (cp->sync_state != 1) return; 312 313 // Search the stream for our synchronization key. This is made 314 // complicated by the fact that in order to be honest with 315 // ourselves here we must search across buffer boundaries... 316 mutex_lock(&cp->mutex); 317 while (1) { 318 // Ensure we have a buffer 319 if (!pvr2_ioread_get_buffer(cp)) break; 320 if (!cp->c_data_len) break; 321 322 // Now walk the buffer contents until we match the key or 323 // run out of buffer data. 324 for (idx = cp->c_data_offs; idx < cp->c_data_len; idx++) { 325 if (cp->sync_buf_offs >= cp->sync_key_len) break; 326 if (cp->c_data_ptr[idx] == 327 cp->sync_key_ptr[cp->sync_buf_offs]) { 328 // Found the next key byte 329 (cp->sync_buf_offs)++; 330 } else { 331 // Whoops, mismatched. Start key over... 332 cp->sync_buf_offs = 0; 333 } 334 } 335 336 // Consume what we've walked through 337 cp->c_data_offs += idx; 338 cp->sync_trashed_count += idx; 339 340 // If we've found the key, then update state and get out. 341 if (cp->sync_buf_offs >= cp->sync_key_len) { 342 cp->sync_trashed_count -= cp->sync_key_len; 343 pvr2_trace(PVR2_TRACE_DATA_FLOW, 344 "/*---TRACE_READ---*/ sync_state <== 2 (skipped %u bytes)", 345 cp->sync_trashed_count); 346 cp->sync_state = 2; 347 cp->sync_buf_offs = 0; 348 break; 349 } 350 351 if (cp->c_data_offs < cp->c_data_len) { 352 // Sanity check - should NEVER get here 353 pvr2_trace(PVR2_TRACE_ERROR_LEGS, 354 "ERROR: pvr2_ioread filter sync problem len=%u offs=%u", 355 cp->c_data_len,cp->c_data_offs); 356 // Get out so we don't get stuck in an infinite 357 // loop. 358 break; 359 } 360 361 continue; // (for clarity) 362 } 363 mutex_unlock(&cp->mutex); 364 } 365 366 int pvr2_ioread_avail(struct pvr2_ioread *cp) 367 { 368 int ret; 369 if (!(cp->enabled)) { 370 // Stream is not enabled; so this is an I/O error 371 return -EIO; 372 } 373 374 if (cp->sync_state == 1) { 375 pvr2_ioread_filter(cp); 376 if (cp->sync_state == 1) return -EAGAIN; 377 } 378 379 ret = 0; 380 if (cp->stream_running) { 381 if (!pvr2_stream_get_ready_count(cp->stream)) { 382 // No data available at all right now. 383 ret = -EAGAIN; 384 } 385 } else { 386 if (pvr2_stream_get_ready_count(cp->stream) < BUFFER_COUNT/2) { 387 // Haven't buffered up enough yet; try again later 388 ret = -EAGAIN; 389 } 390 } 391 392 if ((!(cp->spigot_open)) != (!(ret == 0))) { 393 cp->spigot_open = (ret == 0); 394 pvr2_trace(PVR2_TRACE_DATA_FLOW, 395 "/*---TRACE_READ---*/ data is %s", 396 cp->spigot_open ? "available" : "pending"); 397 } 398 399 return ret; 400 } 401 402 int pvr2_ioread_read(struct pvr2_ioread *cp,void __user *buf,unsigned int cnt) 403 { 404 unsigned int copied_cnt; 405 unsigned int bcnt; 406 const char *src; 407 int stat; 408 int ret = 0; 409 unsigned int req_cnt = cnt; 410 411 if (!cnt) { 412 pvr2_trace(PVR2_TRACE_TRAP, 413 "/*---TRACE_READ---*/ pvr2_ioread_read id=%p ZERO Request? Returning zero.", 414 cp); 415 return 0; 416 } 417 418 stat = pvr2_ioread_avail(cp); 419 if (stat < 0) return stat; 420 421 cp->stream_running = !0; 422 423 mutex_lock(&cp->mutex); 424 do { 425 426 // Suck data out of the buffers and copy to the user 427 copied_cnt = 0; 428 if (!buf) cnt = 0; 429 while (1) { 430 if (!pvr2_ioread_get_buffer(cp)) { 431 ret = -EIO; 432 break; 433 } 434 435 if (!cnt) break; 436 437 if (cp->sync_state == 2) { 438 // We're repeating the sync key data into 439 // the stream. 440 src = cp->sync_key_ptr + cp->sync_buf_offs; 441 bcnt = cp->sync_key_len - cp->sync_buf_offs; 442 } else { 443 // Normal buffer copy 444 src = cp->c_data_ptr + cp->c_data_offs; 445 bcnt = cp->c_data_len - cp->c_data_offs; 446 } 447 448 if (!bcnt) break; 449 450 // Don't run past user's buffer 451 if (bcnt > cnt) bcnt = cnt; 452 453 if (copy_to_user(buf,src,bcnt)) { 454 // User supplied a bad pointer? 455 // Give up - this *will* cause data 456 // to be lost. 457 ret = -EFAULT; 458 break; 459 } 460 cnt -= bcnt; 461 buf += bcnt; 462 copied_cnt += bcnt; 463 464 if (cp->sync_state == 2) { 465 // Update offset inside sync key that we're 466 // repeating back out. 467 cp->sync_buf_offs += bcnt; 468 if (cp->sync_buf_offs >= cp->sync_key_len) { 469 // Consumed entire key; switch mode 470 // to normal. 471 pvr2_trace(PVR2_TRACE_DATA_FLOW, 472 "/*---TRACE_READ---*/ sync_state <== 0"); 473 cp->sync_state = 0; 474 } 475 } else { 476 // Update buffer offset. 477 cp->c_data_offs += bcnt; 478 } 479 } 480 481 } while (0); 482 mutex_unlock(&cp->mutex); 483 484 if (!ret) { 485 if (copied_cnt) { 486 // If anything was copied, return that count 487 ret = copied_cnt; 488 } else { 489 // Nothing copied; suggest to caller that another 490 // attempt should be tried again later 491 ret = -EAGAIN; 492 } 493 } 494 495 pvr2_trace(PVR2_TRACE_DATA_FLOW, 496 "/*---TRACE_READ---*/ pvr2_ioread_read id=%p request=%d result=%d", 497 cp,req_cnt,ret); 498 return ret; 499 } 500