1 /* 2 * Tegra host1x Syncpoints 3 * 4 * Copyright (c) 2010-2013, 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 for (i = 0; i < host->info->nb_pts && sp->name; i++, sp++) 65 ; 66 67 if (i >= host->info->nb_pts) 68 return NULL; 69 70 if (flags & HOST1X_SYNCPT_HAS_BASE) { 71 sp->base = host1x_syncpt_base_request(host); 72 if (!sp->base) 73 return NULL; 74 } 75 76 name = kasprintf(GFP_KERNEL, "%02u-%s", sp->id, 77 dev ? dev_name(dev) : NULL); 78 if (!name) 79 return NULL; 80 81 sp->dev = dev; 82 sp->name = name; 83 84 if (flags & HOST1X_SYNCPT_CLIENT_MANAGED) 85 sp->client_managed = true; 86 else 87 sp->client_managed = false; 88 89 return sp; 90 } 91 92 u32 host1x_syncpt_id(struct host1x_syncpt *sp) 93 { 94 return sp->id; 95 } 96 EXPORT_SYMBOL(host1x_syncpt_id); 97 98 /* 99 * Updates the value sent to hardware. 100 */ 101 u32 host1x_syncpt_incr_max(struct host1x_syncpt *sp, u32 incrs) 102 { 103 return (u32)atomic_add_return(incrs, &sp->max_val); 104 } 105 EXPORT_SYMBOL(host1x_syncpt_incr_max); 106 107 /* 108 * Write cached syncpoint and waitbase values to hardware. 109 */ 110 void host1x_syncpt_restore(struct host1x *host) 111 { 112 struct host1x_syncpt *sp_base = host->syncpt; 113 unsigned int i; 114 115 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) 116 host1x_hw_syncpt_restore(host, sp_base + i); 117 118 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 119 host1x_hw_syncpt_restore_wait_base(host, sp_base + i); 120 121 wmb(); 122 } 123 124 /* 125 * Update the cached syncpoint and waitbase values by reading them 126 * from the registers. 127 */ 128 void host1x_syncpt_save(struct host1x *host) 129 { 130 struct host1x_syncpt *sp_base = host->syncpt; 131 unsigned int i; 132 133 for (i = 0; i < host1x_syncpt_nb_pts(host); i++) { 134 if (host1x_syncpt_client_managed(sp_base + i)) 135 host1x_hw_syncpt_load(host, sp_base + i); 136 else 137 WARN_ON(!host1x_syncpt_idle(sp_base + i)); 138 } 139 140 for (i = 0; i < host1x_syncpt_nb_bases(host); i++) 141 host1x_hw_syncpt_load_wait_base(host, sp_base + i); 142 } 143 144 /* 145 * Updates the cached syncpoint value by reading a new value from the hardware 146 * register 147 */ 148 u32 host1x_syncpt_load(struct host1x_syncpt *sp) 149 { 150 u32 val; 151 152 val = host1x_hw_syncpt_load(sp->host, sp); 153 trace_host1x_syncpt_load_min(sp->id, val); 154 155 return val; 156 } 157 158 /* 159 * Get the current syncpoint base 160 */ 161 u32 host1x_syncpt_load_wait_base(struct host1x_syncpt *sp) 162 { 163 host1x_hw_syncpt_load_wait_base(sp->host, sp); 164 165 return sp->base_val; 166 } 167 168 /* 169 * Increment syncpoint value from cpu, updating cache 170 */ 171 int host1x_syncpt_incr(struct host1x_syncpt *sp) 172 { 173 return host1x_hw_syncpt_cpu_incr(sp->host, sp); 174 } 175 EXPORT_SYMBOL(host1x_syncpt_incr); 176 177 /* 178 * Updated sync point form hardware, and returns true if syncpoint is expired, 179 * false if we may need to wait 180 */ 181 static bool syncpt_load_min_is_expired(struct host1x_syncpt *sp, u32 thresh) 182 { 183 host1x_hw_syncpt_load(sp->host, sp); 184 185 return host1x_syncpt_is_expired(sp, thresh); 186 } 187 188 /* 189 * Main entrypoint for syncpoint value waits. 190 */ 191 int host1x_syncpt_wait(struct host1x_syncpt *sp, u32 thresh, long timeout, 192 u32 *value) 193 { 194 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq); 195 void *ref; 196 struct host1x_waitlist *waiter; 197 int err = 0, check_count = 0; 198 u32 val; 199 200 if (value) 201 *value = 0; 202 203 /* first check cache */ 204 if (host1x_syncpt_is_expired(sp, thresh)) { 205 if (value) 206 *value = host1x_syncpt_load(sp); 207 208 return 0; 209 } 210 211 /* try to read from register */ 212 val = host1x_hw_syncpt_load(sp->host, sp); 213 if (host1x_syncpt_is_expired(sp, thresh)) { 214 if (value) 215 *value = val; 216 217 goto done; 218 } 219 220 if (!timeout) { 221 err = -EAGAIN; 222 goto done; 223 } 224 225 /* allocate a waiter */ 226 waiter = kzalloc(sizeof(*waiter), GFP_KERNEL); 227 if (!waiter) { 228 err = -ENOMEM; 229 goto done; 230 } 231 232 /* schedule a wakeup when the syncpoint value is reached */ 233 err = host1x_intr_add_action(sp->host, sp->id, thresh, 234 HOST1X_INTR_ACTION_WAKEUP_INTERRUPTIBLE, 235 &wq, waiter, &ref); 236 if (err) 237 goto done; 238 239 err = -EAGAIN; 240 /* Caller-specified timeout may be impractically low */ 241 if (timeout < 0) 242 timeout = LONG_MAX; 243 244 /* wait for the syncpoint, or timeout, or signal */ 245 while (timeout) { 246 long check = min_t(long, SYNCPT_CHECK_PERIOD, timeout); 247 int remain; 248 249 remain = wait_event_interruptible_timeout(wq, 250 syncpt_load_min_is_expired(sp, thresh), 251 check); 252 if (remain > 0 || host1x_syncpt_is_expired(sp, thresh)) { 253 if (value) 254 *value = host1x_syncpt_load(sp); 255 256 err = 0; 257 258 break; 259 } 260 261 if (remain < 0) { 262 err = remain; 263 break; 264 } 265 266 timeout -= check; 267 268 if (timeout && check_count <= MAX_STUCK_CHECK_COUNT) { 269 dev_warn(sp->host->dev, 270 "%s: syncpoint id %u (%s) stuck waiting %d, timeout=%ld\n", 271 current->comm, sp->id, sp->name, 272 thresh, timeout); 273 274 host1x_debug_dump_syncpts(sp->host); 275 276 if (check_count == MAX_STUCK_CHECK_COUNT) 277 host1x_debug_dump(sp->host); 278 279 check_count++; 280 } 281 } 282 283 host1x_intr_put_ref(sp->host, sp->id, ref); 284 285 done: 286 return err; 287 } 288 EXPORT_SYMBOL(host1x_syncpt_wait); 289 290 /* 291 * Returns true if syncpoint is expired, false if we may need to wait 292 */ 293 bool host1x_syncpt_is_expired(struct host1x_syncpt *sp, u32 thresh) 294 { 295 u32 current_val; 296 u32 future_val; 297 298 smp_rmb(); 299 300 current_val = (u32)atomic_read(&sp->min_val); 301 future_val = (u32)atomic_read(&sp->max_val); 302 303 /* Note the use of unsigned arithmetic here (mod 1<<32). 304 * 305 * c = current_val = min_val = the current value of the syncpoint. 306 * t = thresh = the value we are checking 307 * f = future_val = max_val = the value c will reach when all 308 * outstanding increments have completed. 309 * 310 * Note that c always chases f until it reaches f. 311 * 312 * Dtf = (f - t) 313 * Dtc = (c - t) 314 * 315 * Consider all cases: 316 * 317 * A) .....c..t..f..... Dtf < Dtc need to wait 318 * B) .....c.....f..t.. Dtf > Dtc expired 319 * C) ..t..c.....f..... Dtf > Dtc expired (Dct very large) 320 * 321 * Any case where f==c: always expired (for any t). Dtf == Dcf 322 * Any case where t==c: always expired (for any f). Dtf >= Dtc (because Dtc==0) 323 * Any case where t==f!=c: always wait. Dtf < Dtc (because Dtf==0, 324 * Dtc!=0) 325 * 326 * Other cases: 327 * 328 * A) .....t..f..c..... Dtf < Dtc need to wait 329 * A) .....f..c..t..... Dtf < Dtc need to wait 330 * A) .....f..t..c..... Dtf > Dtc expired 331 * 332 * So: 333 * Dtf >= Dtc implies EXPIRED (return true) 334 * Dtf < Dtc implies WAIT (return false) 335 * 336 * Note: If t is expired then we *cannot* wait on it. We would wait 337 * forever (hang the system). 338 * 339 * Note: do NOT get clever and remove the -thresh from both sides. It 340 * is NOT the same. 341 * 342 * If future valueis zero, we have a client managed sync point. In that 343 * case we do a direct comparison. 344 */ 345 if (!host1x_syncpt_client_managed(sp)) 346 return future_val - thresh >= current_val - thresh; 347 else 348 return (s32)(current_val - thresh) >= 0; 349 } 350 351 /* remove a wait pointed to by patch_addr */ 352 int host1x_syncpt_patch_wait(struct host1x_syncpt *sp, void *patch_addr) 353 { 354 return host1x_hw_syncpt_patch_wait(sp->host, sp, patch_addr); 355 } 356 357 int host1x_syncpt_init(struct host1x *host) 358 { 359 struct host1x_syncpt_base *bases; 360 struct host1x_syncpt *syncpt; 361 unsigned int i; 362 363 syncpt = devm_kcalloc(host->dev, host->info->nb_pts, sizeof(*syncpt), 364 GFP_KERNEL); 365 if (!syncpt) 366 return -ENOMEM; 367 368 bases = devm_kcalloc(host->dev, host->info->nb_bases, sizeof(*bases), 369 GFP_KERNEL); 370 if (!bases) 371 return -ENOMEM; 372 373 for (i = 0; i < host->info->nb_pts; i++) { 374 syncpt[i].id = i; 375 syncpt[i].host = host; 376 } 377 378 for (i = 0; i < host->info->nb_bases; i++) 379 bases[i].id = i; 380 381 host->syncpt = syncpt; 382 host->bases = bases; 383 384 host1x_syncpt_restore(host); 385 386 /* Allocate sync point to use for clearing waits for expired fences */ 387 host->nop_sp = host1x_syncpt_alloc(host, NULL, 0); 388 if (!host->nop_sp) 389 return -ENOMEM; 390 391 return 0; 392 } 393 394 struct host1x_syncpt *host1x_syncpt_request(struct device *dev, 395 unsigned long flags) 396 { 397 struct host1x *host = dev_get_drvdata(dev->parent); 398 399 return host1x_syncpt_alloc(host, dev, flags); 400 } 401 EXPORT_SYMBOL(host1x_syncpt_request); 402 403 void host1x_syncpt_free(struct host1x_syncpt *sp) 404 { 405 if (!sp) 406 return; 407 408 host1x_syncpt_base_free(sp->base); 409 kfree(sp->name); 410 sp->base = NULL; 411 sp->dev = NULL; 412 sp->name = NULL; 413 sp->client_managed = false; 414 } 415 EXPORT_SYMBOL(host1x_syncpt_free); 416 417 void host1x_syncpt_deinit(struct host1x *host) 418 { 419 struct host1x_syncpt *sp = host->syncpt; 420 unsigned int i; 421 422 for (i = 0; i < host->info->nb_pts; i++, sp++) 423 kfree(sp->name); 424 } 425 426 /* 427 * Read max. It indicates how many operations there are in queue, either in 428 * channel or in a software thread. 429 */ 430 u32 host1x_syncpt_read_max(struct host1x_syncpt *sp) 431 { 432 smp_rmb(); 433 434 return (u32)atomic_read(&sp->max_val); 435 } 436 EXPORT_SYMBOL(host1x_syncpt_read_max); 437 438 /* 439 * Read min, which is a shadow of the current sync point value in hardware. 440 */ 441 u32 host1x_syncpt_read_min(struct host1x_syncpt *sp) 442 { 443 smp_rmb(); 444 445 return (u32)atomic_read(&sp->min_val); 446 } 447 EXPORT_SYMBOL(host1x_syncpt_read_min); 448 449 u32 host1x_syncpt_read(struct host1x_syncpt *sp) 450 { 451 return host1x_syncpt_load(sp); 452 } 453 EXPORT_SYMBOL(host1x_syncpt_read); 454 455 unsigned int host1x_syncpt_nb_pts(struct host1x *host) 456 { 457 return host->info->nb_pts; 458 } 459 460 unsigned int host1x_syncpt_nb_bases(struct host1x *host) 461 { 462 return host->info->nb_bases; 463 } 464 465 unsigned int host1x_syncpt_nb_mlocks(struct host1x *host) 466 { 467 return host->info->nb_mlocks; 468 } 469 470 struct host1x_syncpt *host1x_syncpt_get(struct host1x *host, unsigned int id) 471 { 472 if (host->info->nb_pts < id) 473 return NULL; 474 475 return host->syncpt + id; 476 } 477 EXPORT_SYMBOL(host1x_syncpt_get); 478 479 struct host1x_syncpt_base *host1x_syncpt_get_base(struct host1x_syncpt *sp) 480 { 481 return sp ? sp->base : NULL; 482 } 483 EXPORT_SYMBOL(host1x_syncpt_get_base); 484 485 u32 host1x_syncpt_base_id(struct host1x_syncpt_base *base) 486 { 487 return base->id; 488 } 489 EXPORT_SYMBOL(host1x_syncpt_base_id); 490