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 static struct host1x_syncpt *host1x_syncpt_alloc(struct host1x *host, 46 struct host1x_client *client, 47 unsigned long flags) 48 { 49 struct host1x_syncpt *sp = host->syncpt; 50 unsigned int i; 51 char *name; 52 53 mutex_lock(&host->syncpt_mutex); 54 55 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++) 56 ; 57 58 if (i >= host->info->nb_pts) 59 goto unlock; 60 61 if (flags & HOST1X_SYNCPT_HAS_BASE) { 62 sp->base = host1x_syncpt_base_request(host); 63 if (!sp->base) 64 goto unlock; 65 } 66 67 name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id, 68 client ? dev_name(client->dev) : NULL); 69 if (!name) 70 goto free_base; 71 72 sp->client = client; 73 sp->name = name; 74 75 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED) 76 sp->client_managed = true; 77 else 78 sp->client_managed = false; 79 80 mutex_unlock(&host->syncpt_mutex); 81 return sp; 82 83 free_base: 84 host1x_syncpt_base_free(sp->base); 85 sp->base = NULL; 86 unlock: 87 mutex_unlock(&host->syncpt_mutex); 88 return NULL; 89 } 90 91 /** 92 * host1x_syncpt_id() - retrieve syncpoint ID 93 * @sp: host1x syncpoint 94 * 95 * Given a pointer to a struct host1x_syncpt, retrieves its ID. This ID is 96 * often used as a value to program into registers that control how hardware 97 * blocks interact with syncpoints. 98 */ 99 u32 host1x_syncpt_id(struct host1x_syncpt *sp) 100 { 101 return sp->id; 102 } 103 EXPORT_SYMBOL(host1x_syncpt_id); 104 105 /** 106 * host1x_syncpt_incr_max() - update the value sent to hardware 107 * @sp: host1x syncpoint 108 * @incrs: number of increments 109 */ 110 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs) 111 { 112 return (u32)atomic_add_return(incrs, &sp->max_val); 113 } 114 EXPORT_SYMBOL(host1x_syncpt_incr_max); 115 116 /* 117 * Write cached syncpoint and waitbase values to hardware. 118 */ 119 void host1x_syncpt_restore(struct host1x *host) 120 { 121 struct host1x_syncpt *sp_base = host->syncpt; 122 unsigned int i; 123 124 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) 125 host1x_hw_syncpt_restore(host, sp_base + i); 126 127 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 128 host1x_hw_syncpt_restore_wait_base(host, sp_base + i); 129 130 wmb(); 131 } 132 133 /* 134 * Update the cached syncpoint and waitbase values by reading them 135 * from the registers. 136 */ 137 void host1x_syncpt_save(struct host1x *host) 138 { 139 struct host1x_syncpt *sp_base = host->syncpt; 140 unsigned int i; 141 142 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) { 143 if (host1x_syncpt_client_managed(sp_base + i)) 144 host1x_hw_syncpt_load(host, sp_base + i); 145 else 146 WARN_ON(!host1x_syncpt_idle(sp_base + i)); 147 } 148 149 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 150 host1x_hw_syncpt_load_wait_base(host, sp_base + i); 151 } 152 153 /* 154 * Updates the cached syncpoint value by reading a new value from the hardware 155 * register 156 */ 157 u32 host1x_syncpt_load(struct host1x_syncpt *sp) 158 { 159 u32 val; 160 161 val = host1x_hw_syncpt_load(sp->host, sp); 162 trace_host1x_syncpt_load_min(sp->id, val); 163 164 return val; 165 } 166 167 /* 168 * Get the current syncpoint base 169 */ 170 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp) 171 { 172 host1x_hw_syncpt_load_wait_base(sp->host, sp); 173 174 return sp->base_val; 175 } 176 177 /** 178 * host1x_syncpt_incr() - increment syncpoint value from CPU, updating cache 179 * @sp: host1x syncpoint 180 */ 181 int host1x_syncpt_incr(struct host1x_syncpt *sp) 182 { 183 return host1x_hw_syncpt_cpu_incr(sp->host, sp); 184 } 185 EXPORT_SYMBOL(host1x_syncpt_incr); 186 187 /* 188 * Updated sync point form hardware, and returns true if syncpoint is expired, 189 * false if we may need to wait 190 */ 191 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh) 192 { 193 host1x_hw_syncpt_load(sp->host, sp); 194 195 return host1x_syncpt_is_expired(sp, thresh); 196 } 197 198 /** 199 * host1x_syncpt_wait() - wait for a syncpoint to reach a given value 200 * @sp: host1x syncpoint 201 * @thresh: threshold 202 * @timeout: maximum time to wait for the syncpoint to reach the given value 203 * @value: return location for the syncpoint value 204 */ 205 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout, 206 u32 *value) 207 { 208 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 209 void *ref; 210 struct host1x_waitlist *waiter; 211 int err = 0, check_count = 0; 212 u32 val; 213 214 if (value) 215 *value = 0; 216 217 /* first check cache */ 218 if (host1x_syncpt_is_expired(sp, thresh)) { 219 if (value) 220 *value = host1x_syncpt_load(sp); 221 222 return 0; 223 } 224 225 /* try to read from register */ 226 val = host1x_hw_syncpt_load(sp->host, sp); 227 if (host1x_syncpt_is_expired(sp, thresh)) { 228 if (value) 229 *value = val; 230 231 goto done; 232 } 233 234 if (!timeout) { 235 err = -EAGAIN; 236 goto done; 237 } 238 239 /* allocate a waiter */ 240 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL); 241 if (!waiter) { 242 err = -ENOMEM; 243 goto done; 244 } 245 246 /* schedule a wakeup when the syncpoint value is reached */ 247 err = host1x_intr_add_action(sp->host, sp, thresh, 248 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE, 249 &wq, waiter, &ref); 250 if (err) 251 goto done; 252 253 err = -EAGAIN; 254 /* Caller-specified timeout may be impractically low */ 255 if (timeout < 0) 256 timeout = LONG_MAX; 257 258 /* wait for the syncpoint, or timeout, or signal */ 259 while (timeout) { 260 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout); 261 int remain; 262 263 remain = wait_event_interruptible_timeout(wq, 264 syncpt_load_min_is_expired(sp, thresh), 265 check); 266 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) { 267 if (value) 268 *value = host1x_syncpt_load(sp); 269 270 err = 0; 271 272 break; 273 } 274 275 if (remain < 0) { 276 err = remain; 277 break; 278 } 279 280 timeout -= check; 281 282 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) { 283 dev_warn(sp->host->dev, 284 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n", 285 current->comm, sp->id, sp->name, 286 thresh, timeout); 287 288 host1x_debug_dump_syncpts(sp->host); 289 290 if (check_count == MAX_STUCK_CHECK_COUNT) 291 host1x_debug_dump(sp->host); 292 293 check_count++; 294 } 295 } 296 297 host1x_intr_put_ref(sp->host, sp->id, ref); 298 299 done: 300 return err; 301 } 302 EXPORT_SYMBOL(host1x_syncpt_wait); 303 304 /* 305 * Returns true if syncpoint is expired, false if we may need to wait 306 */ 307 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh) 308 { 309 u32 current_val; 310 u32 future_val; 311 312 smp_rmb(); 313 314 current_val = (u32)atomic_read(&sp->min_val); 315 future_val = (u32)atomic_read(&sp->max_val); 316 317 /* Note the use of unsigned arithmetic here (mod 1<<32). 318 * 319 * c = current_val = min_val = the current value of the syncpoint. 320 * t = thresh = the value we are checking 321 * f = future_val = max_val = the value c will reach when all 322 * outstanding increments have completed. 323 * 324 * Note that c always chases f until it reaches f. 325 * 326 * Dtf = (f - t) 327 * Dtc = (c - t) 328 * 329 * Consider all cases: 330 * 331 * A) .....c..t..f..... Dtf < Dtc need to wait 332 * B) .....c.....f..t.. Dtf > Dtc expired 333 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large) 334 * 335 * Any case where f==c: always expired (for any t). Dtf == Dcf 336 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0) 337 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0, 338 * Dtc!=0) 339 * 340 * Other cases: 341 * 342 * A) .....t..f..c..... Dtf < Dtc need to wait 343 * A) .....f..c..t..... Dtf < Dtc need to wait 344 * A) .....f..t..c..... Dtf > Dtc expired 345 * 346 * So: 347 * Dtf >= Dtc implies EXPIRED (return true) 348 * Dtf < Dtc implies WAIT (return false) 349 * 350 * Note: If t is expired then we *cannot* wait on it. We would wait 351 * forever (hang the system). 352 * 353 * Note: do NOT get clever and remove the -thresh from both sides. It 354 * is NOT the same. 355 * 356 * If future valueis zero, we have a client managed sync point. In that 357 * case we do a direct comparison. 358 */ 359 if (!host1x_syncpt_client_managed(sp)) 360 return future_val - thresh >= current_val - thresh; 361 else 362 return (s32)(current_val - thresh) >= 0; 363 } 364 365 int host1x_syncpt_init(struct host1x *host) 366 { 367 struct host1x_syncpt_base *bases; 368 struct host1x_syncpt *syncpt; 369 unsigned int i; 370 371 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt), 372 GFP_KERNEL); 373 if (!syncpt) 374 return -ENOMEM; 375 376 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases), 377 GFP_KERNEL); 378 if (!bases) 379 return -ENOMEM; 380 381 for (i = 0; i < host->info->nb_pts; i++) { 382 syncpt[i].id = i; 383 syncpt[i].host = host; 384 385 /* 386 * Unassign syncpt from channels for purposes of Tegra186 387 * syncpoint protection. This prevents any channel from 388 * accessing it until it is reassigned. 389 */ 390 host1x_hw_syncpt_assign_to_channel(host, &syncpt[i], NULL); 391 } 392 393 for (i = 0; i < host->info->nb_bases; i++) 394 bases[i].id = i; 395 396 mutex_init(&host->syncpt_mutex); 397 host->syncpt = syncpt; 398 host->bases = bases; 399 400 host1x_syncpt_restore(host); 401 host1x_hw_syncpt_enable_protection(host); 402 403 /* Allocate sync point to use for clearing waits for expired fences */ 404 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0); 405 if (!host->nop_sp) 406 return -ENOMEM; 407 408 return 0; 409 } 410 411 /** 412 * host1x_syncpt_request() - request a syncpoint 413 * @client: client requesting the syncpoint 414 * @flags: flags 415 * 416 * host1x client drivers can use this function to allocate a syncpoint for 417 * subsequent use. A syncpoint returned by this function will be reserved for 418 * use by the client exclusively. When no longer using a syncpoint, a host1x 419 * client driver needs to release it using host1x_syncpt_free(). 420 */ 421 struct host1x_syncpt *host1x_syncpt_request(struct host1x_client *client, 422 unsigned long flags) 423 { 424 struct host1x *host = dev_get_drvdata(client->parent->parent); 425 426 return host1x_syncpt_alloc(host, client, flags); 427 } 428 EXPORT_SYMBOL(host1x_syncpt_request); 429 430 /** 431 * host1x_syncpt_free() - free a requested syncpoint 432 * @sp: host1x syncpoint 433 * 434 * Release a syncpoint previously allocated using host1x_syncpt_request(). A 435 * host1x client driver should call this when the syncpoint is no longer in 436 * use. Note that client drivers must ensure that the syncpoint doesn't remain 437 * under the control of hardware after calling this function, otherwise two 438 * clients may end up trying to access the same syncpoint concurrently. 439 */ 440 void host1x_syncpt_free(struct host1x_syncpt *sp) 441 { 442 if (!sp) 443 return; 444 445 mutex_lock(&sp->host->syncpt_mutex); 446 447 host1x_syncpt_base_free(sp->base); 448 kfree(sp->name); 449 sp->base = NULL; 450 sp->client = NULL; 451 sp->name = NULL; 452 sp->client_managed = false; 453 454 mutex_unlock(&sp->host->syncpt_mutex); 455 } 456 EXPORT_SYMBOL(host1x_syncpt_free); 457 458 void host1x_syncpt_deinit(struct host1x *host) 459 { 460 struct host1x_syncpt *sp = host->syncpt; 461 unsigned int i; 462 463 for (i = 0; i < host->info->nb_pts; i++, sp++) 464 kfree(sp->name); 465 } 466 467 /** 468 * host1x_syncpt_read_max() - read maximum syncpoint value 469 * @sp: host1x syncpoint 470 * 471 * The maximum syncpoint value indicates how many operations there are in 472 * queue, either in channel or in a software thread. 473 */ 474 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp) 475 { 476 smp_rmb(); 477 478 return (u32)atomic_read(&sp->max_val); 479 } 480 EXPORT_SYMBOL(host1x_syncpt_read_max); 481 482 /** 483 * host1x_syncpt_read_min() - read minimum syncpoint value 484 * @sp: host1x syncpoint 485 * 486 * The minimum syncpoint value is a shadow of the current sync point value in 487 * hardware. 488 */ 489 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp) 490 { 491 smp_rmb(); 492 493 return (u32)atomic_read(&sp->min_val); 494 } 495 EXPORT_SYMBOL(host1x_syncpt_read_min); 496 497 /** 498 * host1x_syncpt_read() - read the current syncpoint value 499 * @sp: host1x syncpoint 500 */ 501 u32 host1x_syncpt_read(struct host1x_syncpt *sp) 502 { 503 return host1x_syncpt_load(sp); 504 } 505 EXPORT_SYMBOL(host1x_syncpt_read); 506 507 unsigned int host1x_syncpt_nb_pts(struct host1x *host) 508 { 509 return host->info->nb_pts; 510 } 511 512 unsigned int host1x_syncpt_nb_bases(struct host1x *host) 513 { 514 return host->info->nb_bases; 515 } 516 517 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host) 518 { 519 return host->info->nb_mlocks; 520 } 521 522 /** 523 * host1x_syncpt_get() - obtain a syncpoint by ID 524 * @host: host1x controller 525 * @id: syncpoint ID 526 */ 527 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id) 528 { 529 if (id >= host->info->nb_pts) 530 return NULL; 531 532 return host->syncpt + id; 533 } 534 EXPORT_SYMBOL(host1x_syncpt_get); 535 536 /** 537 * host1x_syncpt_get_base() - obtain the wait base associated with a syncpoint 538 * @sp: host1x syncpoint 539 */ 540 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp) 541 { 542 return sp ? sp->base : NULL; 543 } 544 EXPORT_SYMBOL(host1x_syncpt_get_base); 545 546 /** 547 * host1x_syncpt_base_id() - retrieve the ID of a syncpoint wait base 548 * @base: host1x syncpoint wait base 549 */ 550 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base) 551 { 552 return base->id; 553 } 554 EXPORT_SYMBOL(host1x_syncpt_base_id); 555