1 /* 2 * Tegra host1x Syncpoints 3 * 4 * Copyright (c) 2010-2015, NVIDIA Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program. If not, see <http://www.gnu.org/licenses/>. 17 */ 18 19 #include <linux/module.h> 20 #include <linux/device.h> 21 #include <linux/slab.h> 22 23 #include <trace/events/host1x.h> 24 25 #include "syncpt.h" 26 #include "dev.h" 27 #include "intr.h" 28 #include "debug.h" 29 30 #define SYNCPT_CHECK_PERIOD (2 * HZ) 31 #define MAX_STUCK_CHECK_COUNT 15 32 33 static struct host1x_syncpt_base * 34 host1x_syncpt_base_request(struct host1x *host) 35 { 36 struct host1x_syncpt_base *bases = host->bases; 37 unsigned int i; 38 39 for (i = 0; i < host->info->nb_bases; i++) 40 if (!bases[i].requested) 41 break; 42 43 if (i >= host->info->nb_bases) 44 return NULL; 45 46 bases[i].requested = true; 47 return &bases[i]; 48 } 49 50 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base) 51 { 52 if (base) 53 base->requested = false; 54 } 55 56 static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host, 57 struct device *dev, 58 unsigned long flags) 59 { 60 int i; 61 struct host1x_syncpt *sp = host->syncpt; 62 char *name; 63 64 mutex_lock(&host->syncpt_mutex); 65 66 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++) 67 ; 68 69 if (i >= host->info->nb_pts) 70 goto unlock; 71 72 if (flags & HOST1X_SYNCPT_HAS_BASE) { 73 sp->base = host1x_syncpt_base_request(host); 74 if (!sp->base) 75 goto unlock; 76 } 77 78 name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id, 79 dev ? dev_name(dev) : NULL); 80 if (!name) 81 goto free_base; 82 83 sp->dev = dev; 84 sp->name = name; 85 86 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED) 87 sp->client_managed = true; 88 else 89 sp->client_managed = false; 90 91 mutex_unlock(&host->syncpt_mutex); 92 return sp; 93 94 free_base: 95 host1x_syncpt_base_free(sp->base); 96 sp->base = NULL; 97 unlock: 98 mutex_unlock(&host->syncpt_mutex); 99 return NULL; 100 } 101 102 /** 103 * host1x_syncpt_id() - retrieve syncpoint ID 104 * @sp: host1x syncpoint 105 * 106 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is 107 * often used as a value to program into registers that control how hardware 108 * blocks interact with syncpoints. 109 */ 110 u32 host1x_syncpt_id(struct host1x_syncpt *sp) 111 { 112 return sp->id; 113 } 114 EXPORT_SYMBOL(host1x_syncpt_id); 115 116 /** 117 * host1x_syncpt_incr_max() - update the value sent to hardware 118 * @sp: host1x syncpoint 119 * @incrs: number of increments 120 */ 121 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs) 122 { 123 return (u32)atomic_add_return(incrs, &sp->max_val); 124 } 125 EXPORT_SYMBOL(host1x_syncpt_incr_max); 126 127 /* 128 * Write cached syncpoint and waitbase values to hardware. 129 */ 130 void host1x_syncpt_restore(struct host1x *host) 131 { 132 struct host1x_syncpt *sp_base = host->syncpt; 133 unsigned int i; 134 135 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) 136 host1x_hw_syncpt_restore(host, sp_base + i); 137 138 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 139 host1x_hw_syncpt_restore_wait_base(host, sp_base + i); 140 141 wmb(); 142 } 143 144 /* 145 * Update the cached syncpoint and waitbase values by reading them 146 * from the registers. 147 */ 148 void host1x_syncpt_save(struct host1x *host) 149 { 150 struct host1x_syncpt *sp_base = host->syncpt; 151 unsigned int i; 152 153 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) { 154 if (host1x_syncpt_client_managed(sp_base + i)) 155 host1x_hw_syncpt_load(host, sp_base + i); 156 else 157 WARN_ON(!host1x_syncpt_idle(sp_base + i)); 158 } 159 160 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 161 host1x_hw_syncpt_load_wait_base(host, sp_base + i); 162 } 163 164 /* 165 * Updates the cached syncpoint value by reading a new value from the hardware 166 * register 167 */ 168 u32 host1x_syncpt_load(struct host1x_syncpt *sp) 169 { 170 u32 val; 171 172 val = host1x_hw_syncpt_load(sp->host, sp); 173 trace_host1x_syncpt_load_min(sp->id, val); 174 175 return val; 176 } 177 178 /* 179 * Get the current syncpoint base 180 */ 181 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp) 182 { 183 host1x_hw_syncpt_load_wait_base(sp->host, sp); 184 185 return sp->base_val; 186 } 187 188 /** 189 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache 190 * @sp: host1x syncpoint 191 */ 192 int host1x_syncpt_incr(struct host1x_syncpt *sp) 193 { 194 return host1x_hw_syncpt_cpu_incr(sp->host, sp); 195 } 196 EXPORT_SYMBOL(host1x_syncpt_incr); 197 198 /* 199 * Updated sync point form hardware, and returns true if syncpoint is expired, 200 * false if we may need to wait 201 */ 202 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh) 203 { 204 host1x_hw_syncpt_load(sp->host, sp); 205 206 return host1x_syncpt_is_expired(sp, thresh); 207 } 208 209 /** 210 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value 211 * @sp: host1x syncpoint 212 * @thresh: threshold 213 * @timeout: maximum time to wait for the syncpoint to reach the given value 214 * @value: return location for the syncpoint value 215 */ 216 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout, 217 u32 *value) 218 { 219 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 220 void *ref; 221 struct host1x_waitlist *waiter; 222 int err = 0, check_count = 0; 223 u32 val; 224 225 if (value) 226 *value = 0; 227 228 /* first check cache */ 229 if (host1x_syncpt_is_expired(sp, thresh)) { 230 if (value) 231 *value = host1x_syncpt_load(sp); 232 233 return 0; 234 } 235 236 /* try to read from register */ 237 val = host1x_hw_syncpt_load(sp->host, sp); 238 if (host1x_syncpt_is_expired(sp, thresh)) { 239 if (value) 240 *value = val; 241 242 goto done; 243 } 244 245 if (!timeout) { 246 err = -EAGAIN; 247 goto done; 248 } 249 250 /* allocate a waiter */ 251 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL); 252 if (!waiter) { 253 err = -ENOMEM; 254 goto done; 255 } 256 257 /* schedule a wakeup when the syncpoint value is reached */ 258 err = host1x_intr_add_action(sp->host, sp->id, thresh, 259 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE, 260 &wq, waiter, &ref); 261 if (err) 262 goto done; 263 264 err = -EAGAIN; 265 /* Caller-specified timeout may be impractically low */ 266 if (timeout < 0) 267 timeout = LONG_MAX; 268 269 /* wait for the syncpoint, or timeout, or signal */ 270 while (timeout) { 271 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout); 272 int remain; 273 274 remain = wait_event_interruptible_timeout(wq, 275 syncpt_load_min_is_expired(sp, thresh), 276 check); 277 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) { 278 if (value) 279 *value = host1x_syncpt_load(sp); 280 281 err = 0; 282 283 break; 284 } 285 286 if (remain < 0) { 287 err = remain; 288 break; 289 } 290 291 timeout -= check; 292 293 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) { 294 dev_warn(sp->host->dev, 295 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n", 296 current->comm, sp->id, sp->name, 297 thresh, timeout); 298 299 host1x_debug_dump_syncpts(sp->host); 300 301 if (check_count == MAX_STUCK_CHECK_COUNT) 302 host1x_debug_dump(sp->host); 303 304 check_count++; 305 } 306 } 307 308 host1x_intr_put_ref(sp->host, sp->id, ref); 309 310 done: 311 return err; 312 } 313 EXPORT_SYMBOL(host1x_syncpt_wait); 314 315 /* 316 * Returns true if syncpoint is expired, false if we may need to wait 317 */ 318 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh) 319 { 320 u32 current_val; 321 u32 future_val; 322 323 smp_rmb(); 324 325 current_val = (u32)atomic_read(&sp->min_val); 326 future_val = (u32)atomic_read(&sp->max_val); 327 328 /* Note the use of unsigned arithmetic here (mod 1<<32). 329 * 330 * c = current_val = min_val = the current value of the syncpoint. 331 * t = thresh = the value we are checking 332 * f = future_val = max_val = the value c will reach when all 333 * outstanding increments have completed. 334 * 335 * Note that c always chases f until it reaches f. 336 * 337 * Dtf = (f - t) 338 * Dtc = (c - t) 339 * 340 * Consider all cases: 341 * 342 * A) .....c..t..f..... Dtf < Dtc need to wait 343 * B) .....c.....f..t.. Dtf > Dtc expired 344 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large) 345 * 346 * Any case where f==c: always expired (for any t). Dtf == Dcf 347 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0) 348 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0, 349 * Dtc!=0) 350 * 351 * Other cases: 352 * 353 * A) .....t..f..c..... Dtf < Dtc need to wait 354 * A) .....f..c..t..... Dtf < Dtc need to wait 355 * A) .....f..t..c..... Dtf > Dtc expired 356 * 357 * So: 358 * Dtf >= Dtc implies EXPIRED (return true) 359 * Dtf < Dtc implies WAIT (return false) 360 * 361 * Note: If t is expired then we *cannot* wait on it. We would wait 362 * forever (hang the system). 363 * 364 * Note: do NOT get clever and remove the -thresh from both sides. It 365 * is NOT the same. 366 * 367 * If future valueis zero, we have a client managed sync point. In that 368 * case we do a direct comparison. 369 */ 370 if (!host1x_syncpt_client_managed(sp)) 371 return future_val - thresh >= current_val - thresh; 372 else 373 return (s32)(current_val - thresh) >= 0; 374 } 375 376 /* remove a wait pointed to by patch_addr */ 377 int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr) 378 { 379 return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr); 380 } 381 382 int host1x_syncpt_init(struct host1x *host) 383 { 384 struct host1x_syncpt_base *bases; 385 struct host1x_syncpt *syncpt; 386 unsigned int i; 387 388 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt), 389 GFP_KERNEL); 390 if (!syncpt) 391 return -ENOMEM; 392 393 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases), 394 GFP_KERNEL); 395 if (!bases) 396 return -ENOMEM; 397 398 for (i = 0; i < host->info->nb_pts; i++) { 399 syncpt[i].id = i; 400 syncpt[i].host = host; 401 } 402 403 for (i = 0; i < host->info->nb_bases; i++) 404 bases[i].id = i; 405 406 mutex_init(&host->syncpt_mutex); 407 host->syncpt = syncpt; 408 host->bases = bases; 409 410 host1x_syncpt_restore(host); 411 412 /* Allocate sync point to use for clearing waits for expired fences */ 413 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0); 414 if (!host->nop_sp) 415 return -ENOMEM; 416 417 return 0; 418 } 419 420 /** 421 * host1x_syncpt_request() - request a syncpoint 422 * @dev: device requesting the syncpoint 423 * @flags: flags 424 * 425 * host1x client drivers can use this function to allocate a syncpoint for 426 * subsequent use. A syncpoint returned by this function will be reserved for 427 * use by the client exclusively. When no longer using a syncpoint, a host1x 428 * client driver needs to release it using host1x_syncpt_free(). 429 */ 430 struct host1x_syncpt *host1x_syncpt_request(struct device *dev, 431 unsigned long flags) 432 { 433 struct host1x *host = dev_get_drvdata(dev->parent); 434 435 return host1x_syncpt_alloc(host, dev, flags); 436 } 437 EXPORT_SYMBOL(host1x_syncpt_request); 438 439 /** 440 * host1x_syncpt_free() - free a requested syncpoint 441 * @sp: host1x syncpoint 442 * 443 * Release a syncpoint previously allocated using host1x_syncpt_request(). A 444 * host1x client driver should call this when the syncpoint is no longer in 445 * use. Note that client drivers must ensure that the syncpoint doesn't remain 446 * under the control of hardware after calling this function, otherwise two 447 * clients may end up trying to access the same syncpoint concurrently. 448 */ 449 void host1x_syncpt_free(struct host1x_syncpt *sp) 450 { 451 if (!sp) 452 return; 453 454 mutex_lock(&sp->host->syncpt_mutex); 455 456 host1x_syncpt_base_free(sp->base); 457 kfree(sp->name); 458 sp->base = NULL; 459 sp->dev = NULL; 460 sp->name = NULL; 461 sp->client_managed = false; 462 463 mutex_unlock(&sp->host->syncpt_mutex); 464 } 465 EXPORT_SYMBOL(host1x_syncpt_free); 466 467 void host1x_syncpt_deinit(struct host1x *host) 468 { 469 struct host1x_syncpt *sp = host->syncpt; 470 unsigned int i; 471 472 for (i = 0; i < host->info->nb_pts; i++, sp++) 473 kfree(sp->name); 474 } 475 476 /** 477 * host1x_syncpt_read_max() - read maximum syncpoint value 478 * @sp: host1x syncpoint 479 * 480 * The maximum syncpoint value indicates how many operations there are in 481 * queue, either in channel or in a software thread. 482 */ 483 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp) 484 { 485 smp_rmb(); 486 487 return (u32)atomic_read(&sp->max_val); 488 } 489 EXPORT_SYMBOL(host1x_syncpt_read_max); 490 491 /** 492 * host1x_syncpt_read_min() - read minimum syncpoint value 493 * @sp: host1x syncpoint 494 * 495 * The minimum syncpoint value is a shadow of the current sync point value in 496 * hardware. 497 */ 498 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp) 499 { 500 smp_rmb(); 501 502 return (u32)atomic_read(&sp->min_val); 503 } 504 EXPORT_SYMBOL(host1x_syncpt_read_min); 505 506 /** 507 * host1x_syncpt_read() - read the current syncpoint value 508 * @sp: host1x syncpoint 509 */ 510 u32 host1x_syncpt_read(struct host1x_syncpt *sp) 511 { 512 return host1x_syncpt_load(sp); 513 } 514 EXPORT_SYMBOL(host1x_syncpt_read); 515 516 unsigned int host1x_syncpt_nb_pts(struct host1x *host) 517 { 518 return host->info->nb_pts; 519 } 520 521 unsigned int host1x_syncpt_nb_bases(struct host1x *host) 522 { 523 return host->info->nb_bases; 524 } 525 526 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host) 527 { 528 return host->info->nb_mlocks; 529 } 530 531 /** 532 * host1x_syncpt_get() - obtain a syncpoint by ID 533 * @host: host1x controller 534 * @id: syncpoint ID 535 */ 536 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id) 537 { 538 if (id >= host->info->nb_pts) 539 return NULL; 540 541 return host->syncpt + id; 542 } 543 EXPORT_SYMBOL(host1x_syncpt_get); 544 545 /** 546 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint 547 * @sp: host1x syncpoint 548 */ 549 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp) 550 { 551 return sp ? sp->base : NULL; 552 } 553 EXPORT_SYMBOL(host1x_syncpt_get_base); 554 555 /** 556 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base 557 * @base: host1x syncpoint wait base 558 */ 559 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base) 560 { 561 return base->id; 562 } 563 EXPORT_SYMBOL(host1x_syncpt_base_id); 564