1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Tegra host1x Syncpoints 4 * 5 * Copyright (c) 2010-2015, NVIDIA Corporation. 6 */ 7 8 #include <linux/module.h> 9 #include <linux/device.h> 10 #include <linux/slab.h> 11 12 #include <trace/events/host1x.h> 13 14 #include "syncpt.h" 15 #include "dev.h" 16 #include "intr.h" 17 #include "debug.h" 18 19 #define SYNCPT_CHECK_PERIOD (2 * HZ) 20 #define MAX_STUCK_CHECK_COUNT 15 21 22 static struct host1x_syncpt_base * 23 host1x_syncpt_base_request(struct host1x *host) 24 { 25 struct host1x_syncpt_base *bases = host->bases; 26 unsigned int i; 27 28 for (i = 0; i < host->info->nb_bases; i++) 29 if (!bases[i].requested) 30 break; 31 32 if (i >= host->info->nb_bases) 33 return NULL; 34 35 bases[i].requested = true; 36 return &bases[i]; 37 } 38 39 static void host1x_syncpt_base_free(struct host1x_syncpt_base *base) 40 { 41 if (base) 42 base->requested = false; 43 } 44 45 /** 46 * host1x_syncpt_alloc() - allocate a syncpoint 47 * @host: host1x device data 48 * @flags: bitfield of HOST1X_SYNCPT_* flags 49 * @name: name for the syncpoint for use in debug prints 50 * 51 * Allocates a hardware syncpoint for the caller's use. The caller then has 52 * the sole authority to mutate the syncpoint's value until it is freed again. 53 * 54 * If no free syncpoints are available, or a NULL name was specified, returns 55 * NULL. 56 */ 57 struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host, 58 unsigned long flags, 59 const char *name) 60 { 61 struct host1x_syncpt *sp = host->syncpt; 62 char *full_name; 63 unsigned int i; 64 65 if (!name) 66 return NULL; 67 68 mutex_lock(&host->syncpt_mutex); 69 70 for (i = 0; i < host->info->nb_pts && kref_read(&sp->ref); i++, sp++) 71 ; 72 73 if (i >= host->info->nb_pts) 74 goto unlock; 75 76 if (flags & HOST1X_SYNCPT_HAS_BASE) { 77 sp->base = host1x_syncpt_base_request(host); 78 if (!sp->base) 79 goto unlock; 80 } 81 82 full_name = kasprintf(GFP_KERNEL, "%u-%s", sp->id, name); 83 if (!full_name) 84 goto free_base; 85 86 sp->name = full_name; 87 88 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED) 89 sp->client_managed = true; 90 else 91 sp->client_managed = false; 92 93 kref_init(&sp->ref); 94 95 mutex_unlock(&host->syncpt_mutex); 96 return sp; 97 98 free_base: 99 host1x_syncpt_base_free(sp->base); 100 sp->base = NULL; 101 unlock: 102 mutex_unlock(&host->syncpt_mutex); 103 return NULL; 104 } 105 EXPORT_SYMBOL(host1x_syncpt_alloc); 106 107 /** 108 * host1x_syncpt_id() - retrieve syncpoint ID 109 * @sp: host1x syncpoint 110 * 111 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is 112 * often used as a value to program into registers that control how hardware 113 * blocks interact with syncpoints. 114 */ 115 u32 host1x_syncpt_id(struct host1x_syncpt *sp) 116 { 117 return sp->id; 118 } 119 EXPORT_SYMBOL(host1x_syncpt_id); 120 121 /** 122 * host1x_syncpt_incr_max() - update the value sent to hardware 123 * @sp: host1x syncpoint 124 * @incrs: number of increments 125 */ 126 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs) 127 { 128 return (u32)atomic_add_return(incrs, &sp->max_val); 129 } 130 EXPORT_SYMBOL(host1x_syncpt_incr_max); 131 132 /* 133 * Write cached syncpoint and waitbase values to hardware. 134 */ 135 void host1x_syncpt_restore(struct host1x *host) 136 { 137 struct host1x_syncpt *sp_base = host->syncpt; 138 unsigned int i; 139 140 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) 141 host1x_hw_syncpt_restore(host, sp_base + i); 142 143 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 144 host1x_hw_syncpt_restore_wait_base(host, sp_base + i); 145 146 host1x_hw_syncpt_enable_protection(host); 147 148 wmb(); 149 } 150 151 /* 152 * Update the cached syncpoint and waitbase values by reading them 153 * from the registers. 154 */ 155 void host1x_syncpt_save(struct host1x *host) 156 { 157 struct host1x_syncpt *sp_base = host->syncpt; 158 unsigned int i; 159 160 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) { 161 if (host1x_syncpt_client_managed(sp_base + i)) 162 host1x_hw_syncpt_load(host, sp_base + i); 163 else 164 WARN_ON(!host1x_syncpt_idle(sp_base + i)); 165 } 166 167 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 168 host1x_hw_syncpt_load_wait_base(host, sp_base + i); 169 } 170 171 /* 172 * Updates the cached syncpoint value by reading a new value from the hardware 173 * register 174 */ 175 u32 host1x_syncpt_load(struct host1x_syncpt *sp) 176 { 177 u32 val; 178 179 val = host1x_hw_syncpt_load(sp->host, sp); 180 trace_host1x_syncpt_load_min(sp->id, val); 181 182 return val; 183 } 184 185 /* 186 * Get the current syncpoint base 187 */ 188 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp) 189 { 190 host1x_hw_syncpt_load_wait_base(sp->host, sp); 191 192 return sp->base_val; 193 } 194 195 /** 196 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache 197 * @sp: host1x syncpoint 198 */ 199 int host1x_syncpt_incr(struct host1x_syncpt *sp) 200 { 201 return host1x_hw_syncpt_cpu_incr(sp->host, sp); 202 } 203 EXPORT_SYMBOL(host1x_syncpt_incr); 204 205 /* 206 * Updated sync point form hardware, and returns true if syncpoint is expired, 207 * false if we may need to wait 208 */ 209 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh) 210 { 211 host1x_hw_syncpt_load(sp->host, sp); 212 213 return host1x_syncpt_is_expired(sp, thresh); 214 } 215 216 /** 217 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value 218 * @sp: host1x syncpoint 219 * @thresh: threshold 220 * @timeout: maximum time to wait for the syncpoint to reach the given value 221 * @value: return location for the syncpoint value 222 */ 223 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout, 224 u32 *value) 225 { 226 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 227 void *ref; 228 struct host1x_waitlist *waiter; 229 int err = 0, check_count = 0; 230 u32 val; 231 232 if (value) 233 *value = 0; 234 235 /* first check cache */ 236 if (host1x_syncpt_is_expired(sp, thresh)) { 237 if (value) 238 *value = host1x_syncpt_load(sp); 239 240 return 0; 241 } 242 243 /* try to read from register */ 244 val = host1x_hw_syncpt_load(sp->host, sp); 245 if (host1x_syncpt_is_expired(sp, thresh)) { 246 if (value) 247 *value = val; 248 249 goto done; 250 } 251 252 if (!timeout) { 253 err = -EAGAIN; 254 goto done; 255 } 256 257 /* allocate a waiter */ 258 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL); 259 if (!waiter) { 260 err = -ENOMEM; 261 goto done; 262 } 263 264 /* schedule a wakeup when the syncpoint value is reached */ 265 err = host1x_intr_add_action(sp->host, sp, thresh, 266 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE, 267 &wq, waiter, &ref); 268 if (err) 269 goto done; 270 271 err = -EAGAIN; 272 /* Caller-specified timeout may be impractically low */ 273 if (timeout < 0) 274 timeout = LONG_MAX; 275 276 /* wait for the syncpoint, or timeout, or signal */ 277 while (timeout) { 278 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout); 279 int remain; 280 281 remain = wait_event_interruptible_timeout(wq, 282 syncpt_load_min_is_expired(sp, thresh), 283 check); 284 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) { 285 if (value) 286 *value = host1x_syncpt_load(sp); 287 288 err = 0; 289 290 break; 291 } 292 293 if (remain < 0) { 294 err = remain; 295 break; 296 } 297 298 timeout -= check; 299 300 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) { 301 dev_warn(sp->host->dev, 302 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n", 303 current->comm, sp->id, sp->name, 304 thresh, timeout); 305 306 host1x_debug_dump_syncpts(sp->host); 307 308 if (check_count == MAX_STUCK_CHECK_COUNT) 309 host1x_debug_dump(sp->host); 310 311 check_count++; 312 } 313 } 314 315 host1x_intr_put_ref(sp->host, sp->id, ref, true); 316 317 done: 318 return err; 319 } 320 EXPORT_SYMBOL(host1x_syncpt_wait); 321 322 /* 323 * Returns true if syncpoint is expired, false if we may need to wait 324 */ 325 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh) 326 { 327 u32 current_val; 328 329 smp_rmb(); 330 331 current_val = (u32)atomic_read(&sp->min_val); 332 333 return ((current_val - thresh) & 0x80000000U) == 0U; 334 } 335 336 int host1x_syncpt_init(struct host1x *host) 337 { 338 struct host1x_syncpt_base *bases; 339 struct host1x_syncpt *syncpt; 340 unsigned int i; 341 342 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt), 343 GFP_KERNEL); 344 if (!syncpt) 345 return -ENOMEM; 346 347 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases), 348 GFP_KERNEL); 349 if (!bases) 350 return -ENOMEM; 351 352 for (i = 0; i < host->info->nb_pts; i++) { 353 syncpt[i].id = i; 354 syncpt[i].host = host; 355 356 /* 357 * Unassign syncpt from channels for purposes of Tegra186 358 * syncpoint protection. This prevents any channel from 359 * accessing it until it is reassigned. 360 */ 361 host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL); 362 } 363 364 for (i = 0; i < host->info->nb_bases; i++) 365 bases[i].id = i; 366 367 mutex_init(&host->syncpt_mutex); 368 host->syncpt = syncpt; 369 host->bases = bases; 370 371 /* Allocate sync point to use for clearing waits for expired fences */ 372 host->nop_sp = host1x_syncpt_alloc(host, 0, "reserved-nop"); 373 if (!host->nop_sp) 374 return -ENOMEM; 375 376 if (host->info->reserve_vblank_syncpts) { 377 kref_init(&host->syncpt[26].ref); 378 kref_init(&host->syncpt[27].ref); 379 } 380 381 return 0; 382 } 383 384 /** 385 * host1x_syncpt_request() - request a syncpoint 386 * @client: client requesting the syncpoint 387 * @flags: flags 388 * 389 * host1x client drivers can use this function to allocate a syncpoint for 390 * subsequent use. A syncpoint returned by this function will be reserved for 391 * use by the client exclusively. When no longer using a syncpoint, a host1x 392 * client driver needs to release it using host1x_syncpt_put(). 393 */ 394 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client, 395 unsigned long flags) 396 { 397 struct host1x *host = dev_get_drvdata(client->host->parent); 398 399 return host1x_syncpt_alloc(host, flags, dev_name(client->dev)); 400 } 401 EXPORT_SYMBOL(host1x_syncpt_request); 402 403 static void syncpt_release(struct kref *ref) 404 { 405 struct host1x_syncpt *sp = container_of(ref, struct host1x_syncpt, ref); 406 407 atomic_set(&sp->max_val, host1x_syncpt_read(sp)); 408 409 sp->locked = false; 410 411 mutex_lock(&sp->host->syncpt_mutex); 412 413 host1x_syncpt_base_free(sp->base); 414 kfree(sp->name); 415 sp->base = NULL; 416 sp->name = NULL; 417 sp->client_managed = false; 418 419 mutex_unlock(&sp->host->syncpt_mutex); 420 } 421 422 /** 423 * host1x_syncpt_put() - free a requested syncpoint 424 * @sp: host1x syncpoint 425 * 426 * Release a syncpoint previously allocated using host1x_syncpt_request(). A 427 * host1x client driver should call this when the syncpoint is no longer in 428 * use. 429 */ 430 void host1x_syncpt_put(struct host1x_syncpt *sp) 431 { 432 if (!sp) 433 return; 434 435 kref_put(&sp->ref, syncpt_release); 436 } 437 EXPORT_SYMBOL(host1x_syncpt_put); 438 439 void host1x_syncpt_deinit(struct host1x *host) 440 { 441 struct host1x_syncpt *sp = host->syncpt; 442 unsigned int i; 443 444 for (i = 0; i < host->info->nb_pts; i++, sp++) 445 kfree(sp->name); 446 } 447 448 /** 449 * host1x_syncpt_read_max() - read maximum syncpoint value 450 * @sp: host1x syncpoint 451 * 452 * The maximum syncpoint value indicates how many operations there are in 453 * queue, either in channel or in a software thread. 454 */ 455 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp) 456 { 457 smp_rmb(); 458 459 return (u32)atomic_read(&sp->max_val); 460 } 461 EXPORT_SYMBOL(host1x_syncpt_read_max); 462 463 /** 464 * host1x_syncpt_read_min() - read minimum syncpoint value 465 * @sp: host1x syncpoint 466 * 467 * The minimum syncpoint value is a shadow of the current sync point value in 468 * hardware. 469 */ 470 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp) 471 { 472 smp_rmb(); 473 474 return (u32)atomic_read(&sp->min_val); 475 } 476 EXPORT_SYMBOL(host1x_syncpt_read_min); 477 478 /** 479 * host1x_syncpt_read() - read the current syncpoint value 480 * @sp: host1x syncpoint 481 */ 482 u32 host1x_syncpt_read(struct host1x_syncpt *sp) 483 { 484 return host1x_syncpt_load(sp); 485 } 486 EXPORT_SYMBOL(host1x_syncpt_read); 487 488 unsigned int host1x_syncpt_nb_pts(struct host1x *host) 489 { 490 return host->info->nb_pts; 491 } 492 493 unsigned int host1x_syncpt_nb_bases(struct host1x *host) 494 { 495 return host->info->nb_bases; 496 } 497 498 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host) 499 { 500 return host->info->nb_mlocks; 501 } 502 503 /** 504 * host1x_syncpt_get_by_id() - obtain a syncpoint by ID 505 * @host: host1x controller 506 * @id: syncpoint ID 507 */ 508 struct host1x_syncpt *host1x_syncpt_get_by_id(struct host1x *host, 509 unsigned int id) 510 { 511 if (id >= host->info->nb_pts) 512 return NULL; 513 514 if (kref_get_unless_zero(&host->syncpt[id].ref)) 515 return &host->syncpt[id]; 516 else 517 return NULL; 518 } 519 EXPORT_SYMBOL(host1x_syncpt_get_by_id); 520 521 /** 522 * host1x_syncpt_get_by_id_noref() - obtain a syncpoint by ID but don't 523 * increase the refcount. 524 * @host: host1x controller 525 * @id: syncpoint ID 526 */ 527 struct host1x_syncpt *host1x_syncpt_get_by_id_noref(struct host1x *host, 528 unsigned int id) 529 { 530 if (id >= host->info->nb_pts) 531 return NULL; 532 533 return &host->syncpt[id]; 534 } 535 EXPORT_SYMBOL(host1x_syncpt_get_by_id_noref); 536 537 /** 538 * host1x_syncpt_get() - increment syncpoint refcount 539 * @sp: syncpoint 540 */ 541 struct host1x_syncpt *host1x_syncpt_get(struct host1x_syncpt *sp) 542 { 543 kref_get(&sp->ref); 544 545 return sp; 546 } 547 EXPORT_SYMBOL(host1x_syncpt_get); 548 549 /** 550 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint 551 * @sp: host1x syncpoint 552 */ 553 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp) 554 { 555 return sp ? sp->base : NULL; 556 } 557 EXPORT_SYMBOL(host1x_syncpt_get_base); 558 559 /** 560 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base 561 * @base: host1x syncpoint wait base 562 */ 563 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base) 564 { 565 return base->id; 566 } 567 EXPORT_SYMBOL(host1x_syncpt_base_id); 568 569 static void do_nothing(struct kref *ref) 570 { 571 } 572 573 /** 574 * host1x_syncpt_release_vblank_reservation() - Make VBLANK syncpoint 575 * available for allocation 576 * 577 * @client: host1x bus client 578 * @syncpt_id: syncpoint ID to make available 579 * 580 * Makes VBLANK<i> syncpoint available for allocatation if it was 581 * reserved at initialization time. This should be called by the display 582 * driver after it has ensured that any VBLANK increment programming configured 583 * by the boot chain has been disabled. 584 */ 585 void host1x_syncpt_release_vblank_reservation(struct host1x_client *client, 586 u32 syncpt_id) 587 { 588 struct host1x *host = dev_get_drvdata(client->host->parent); 589 590 if (!host->info->reserve_vblank_syncpts) 591 return; 592 593 kref_put(&host->syncpt[syncpt_id].ref, do_nothing); 594 } 595 EXPORT_SYMBOL(host1x_syncpt_release_vblank_reservation); 596